Patent Grant
9773450
The present disclosure relates to pixel configurations made up of pixels each including, for example, an organic electro-luminescence element (hereinafter also referred to as an EL or an OLED), EL displays (EL display panels) on which EL elements are arranged in a matrix, EL display driving methods, driver IC boards for use in EL displays, flexible boards, etc.
Active-matrix (hereinafter also referred to as AM) organic EL displays on which organic EL elements are arranged in a matrix have been employed as display panels for products such as smartphones. Each EL element has an EL layer between an anode electrode and a cathode electrode. The EL element emits light triggered by a current or a voltage supplied between the anode and cathode electrodes (terminals) (for example, see Patent Literature 1).
The liquid crystal display panel (LCD) includes gate signal lines arranged on a per pixel basis. EL displays each include pixels each including at least two gate signal lines formed or arranged therein, and most of the EL displays include pixels through which three or four gate signal lines are formed or arranged (for example, see Patent Literature 2).
Patent Literature 1 discloses a configuration in which connection transmission lines which electrically connect input transmission lines and output transmission lines on a flexible board (COF (chip on film)) mounting driver ICs of an active-matrix (this may be abbreviated as AM below) organic EL display having organic EL elements in the shape of a matrix.
Patent Literature 2 discloses a configuration in which input signal lines etc. are formed in serial connection on a flexible board mounting driver ICs.]
Japanese Unexamined Patent Application Publication No. 2007-188078
Japanese Unexamined Patent Application Publication No. 2006-049514
An EL display (EL display panel) does not require a backlight for image display, and thus can be provided with a thin panel module. In order to take advantage of the feature of being able to provide the EL display with such a thin panel, a configuration (PCB-less configuration) without any printed circuit board (PCB) is employed for a gate driver IC side.
In the PCB-less configuration, all of power supply lines and control signal lines need to be formed in a COF. The COF has only a single wiring layer, and thus lines formed in the COF cannot intersect each other. For this reason, there is a need to layout the lines etc. in serial connection so as not to generate any intersection parts of the power supply lines and control lines.
However, since the EL display (EL display panel) has a large number of control signal lines, the density of the lines to be formed on the COF is large, and thus a short circuit defect is likely to occur.
The present disclosure was made considering these problems, and has an object to provide EL displays with a reduced number of control lines formed in serial connection on their COFs, with a high yield rate at low cost.
The EL display according to an aspect of the present disclosure includes a panel board on which a plurality of luminescence elements are arranged, and a flexible board on which gate driver ICs for driving the panel board are mounted.
An EL display according to the present disclosure includes: a panel board including a display screen on which pixels each including an EL element are arranged in a matrix; gate signal lines arranged on a per pixel row basis; source signal lines arranged on a per pixel column basis; gate driver circuits mounted on a flexible board; and a source driver circuit which outputs a video signal to the source signal lines. Each of the gate driver circuits includes gate signal output terminals, driver terminals, and control terminals. First connection parts, gate signal connection parts, second connection parts, and third connection parts are arranged on a side of the flexible board. The flexible board includes (i) terminals connection lines which connect terminals and the gate signal connection parts, and (ii) one or more serial connection lines which connect at least two of the connection parts. The control terminals are arranged between the gate signal output terminals and the driver terminals. The gate signal connection parts and the gate signal output terminals are connected with terminal connection lines. The first connection parts, the driver terminals, and the third connection parts are connected with the serial connection lines. Panel lines formed on the panel board are connected to the second connection parts. The second connection parts and the control terminals are connected with terminal connection lines. With this configuration, it is possible to reduce the number of control lines to be formed in serial connection on the COF, and thereby to provide the EL display at low cost, resulting in a high yield rate.
It is to be noted that the driver terminals of the EL display according to the present disclosure may be driver terminals which apply a voltage to the gate driver ICs.
According to the present disclosure, it is possible to reduce the number of control lines to be formed in serial connection on each of the COFs, and thereby to provide EL displays at low cost, resulting in a high yield rate.
Hereinafter, embodiments are described in detail referring to the drawings as appropriate. Unnecessarily detailed descriptions may be omitted. For example, already well-known matters may not be described in detail, and substantially the same configurations may not be described repeatedly. This omission etc. is performed to prevent the following descriptions from being unnecessarily redundant, and to thereby allow any person skilled in the art to easily understand the descriptions.
The Inventors provide the attached drawings and the following descriptions to allow the person skilled in the art to fully understand the present disclosure, without any intention to limit the subject matter of the claims by the drawings and descriptions.
(Underlying Knowledge Forming Basis of the Present Disclosure)
The underlying knowledge forming the basis of the present disclosure is described before the present disclosure is described in detail.
A liquid crystal display panel (LCD) includes gate signal lines formed or arranged on a per pixel basis. On the other hand, an EL display (hereinafter also referred to as an “EL display panel” in the embodiments) includes gate signal lines formed or arranged such that at least two gate signal lines pass through each of pixels. For example, in most EL displays, three or four gate signal lines are formed or arranged on a per pixel basis.
In view of the above-described matters, the EL displays are configured to have a considerably larger number of gate signal lines than that of the LCDs.
An LCD requires an on voltage (Von), an off voltage (Voff), a logic voltage (Vcc), and a video signal voltage (AVdd).
An EL display requires several kinds of on voltages (Von) and also several kinds of off voltages (Voff). The EL display requires also a video signal voltage (AVdd) and a logic voltage (Vcc). The EL display may require an initial voltage (Vini), a reset voltage (Vrst) etc. depending on a pixel circuit configuration. The EL display also requires an anode voltage (Vdd) and a cathode voltage (Vss). In addition, the plurality of gate signal lines each of which controls a corresponding one of pixels operate differently, and control signals for controlling the respective gate signal lines to operate are also required. For this reason, the number of control signals is also large. Accordingly, the number of control signal lines and the number of power supply lines in the EL display are four to five times larger than those of the LCD.
As illustrated in
Likewise, each pixel 16 is connected to a corresponding one of source signal lines 18. Each source signal line 18 has an end connected to a corresponding one of the source driver ICs 14 mounted on a corresponding one of the COF 22s. A printed circuit board (PCB) is connected to the corresponding COF 22s, and a video signal and a control signal are applied from the printed board (PCB) to the corresponding COF 22s.
COFs 22s with the source drivers IC 14 are mounted onto a panel. In addition, a printed circuit board (PCB) 23s is attached to each COF 22s.
In the present disclosure, circuits for driving gate signal lines are described as gate driver ICs 12, but the present disclosure is not limited thereto. For example, the gate driver ICs 12 may be directly formed on a display panel board at the same time when processes of forming a pixel circuit etc. are performed, according to a technique using TAOS, or a low or high temperature polysilicon. In other words, the gate driver ICs are not limited to semiconductor chips, and means gate driver circuits. This applies to the source driver ICs 14, that is, the source driver ICs are not limited to semiconductor chips, and means source driver circuits. Needless to say, no COF is required when driver ICs are directly formed onto a display panel board at the same time when processes of forming a pixel circuit etc. are performed, according to the technique using TAOS, or a low or high temperature polysilicon.
The COF 22g with the gate driver ICs 12 is also mounted onto the panel. No printed circuit board (PCB) is attached to the COF 22g. Stated differently, this is a configuration without any printed circuit board (PCB-less configuration). By employing such a printed circuit board without any PCB (the PCB-less configuration), a thin panel module can be configured.
In each of pixels 16 in
A cathode voltage Vss is applied to the cathode terminal of an EL element 15. An anode voltage Vdd is applied to the source terminal of the driver transistor 11a.
When an on voltage is applied to a gate signal line 17b (Gd), the switch transistor 11d is turned on, and a current for light emission is supplied from the driver transistor 11a to the EL element 15. The EL element 15 emits light based on the magnitude of the current for light emission. The magnitude of the current for light emission is determined by applying the pixel 16 with a video signal applied to a source signal line 18, using a switch transistor 11b.
A terminal of a capacitor 19b is connected to the gate terminal of the driver transistor 11a, and the other terminal of the capacitor 19b is connected to an electrode or seven lines to which an anode voltage (Vdd) is applied. The source terminal of the switch transistor 11b is connected to the source signal line 18, and the drain terminal of the switch transistor 11b is connected to the gate terminal of the driver transistor 11a. On the other hand, a source driver IC 14 applies the source signal line 18 with a video signal.
The gate signal lines 17 (17a, 17b) are connected to the gate driver ICs 12 (12a, 12b) arranged right and left of a display screen 25.
The gate driver ICs 12 (12a, 12b) apply selection voltages (on voltages Von) of the pixels 16 to the gate signal lines 17. The applied on voltages of the gate signal lines 17b turn on the switch transistors 11b, and video signals applied to the source signal lines 18 are applied to the pixels 16.
An EL display panel 49 has the display screen 25 on which the pixels 16 each including the EL element 15 are arranged in a matrix.
With the configuration, even when the display screen is large or for high definition display, it is possible to apply the pixels on the display screen with video signals effectively. In addition, it is possible to prevent luminance slope from occurring on the display screen, and provide excellent image display.
It is to be noted that the driver terminals of the EL display according to the present disclosure may be driver terminals which apply voltages to the gate driver ICs.
In addition, an EL display does not require a backlight for image display, and thus can be provided with a thin panel module. In order to take advantage of the feature of being able to provide the EL display with such a thin panel, a PCB-less configuration is employed for the gate driver ICs 12 (12a, 12b) side as illustrated in
When PCBs are used, it is only necessary that power supply lines and control signal lines for use in the gate driver ICs 12 (12a, 12b) are supplied from the PCBs.
In the configuration without any PCB (PCB-less configuration) as illustrated in
In
As described above, the wiring layout is realized on the panel board 31 in the following serial connection: from the panel line 91a via the connection terminal 75a via the COF line 74a via the driver input terminal 73a via the COF line 74c via the driver input terminal 73b via the COF line 74b via the connection terminal 75b to the panel line 91b.
It is to be noted that outputs of the gate driver ICs 12 are output from driver output terminals 72. The driver output terminals 72 and connection terminals 71 are electrically connected through COF lines 74e. The driver output terminals 72 are electrically connected to gate signal lines 17 using ACF resin.
EL displays each include pixels passed through by at least two gate signal lines, and most of the EL displays include pixels passed through by three or four gate signal lines.
In view of the above-described matters, the EL displays are configured to have a considerably larger number of signal lines than that of the LCDs. Accordingly, the number of control signal lines for controlling the gate signal lines 17 etc. is also large.
The respective gate signal lines of the pixels are for controlling different transistors, and require different voltage amplitudes. Accordingly, an EL display requires several kinds of on voltages (Von) and also requires several kinds of off voltages (Voff). In addition, an initial voltage (Vini) and a reset voltage (Vrst), etc. may be required. In addition, the plurality of gate signal lines each of which controls a corresponding one of pixels operate differently, and control signals for controlling operations of the respective gate signal lines are also required. For this reason, the number of control signals is also large. Accordingly, the number of control signal lines and the number of power supply lines in the EL display are four to five times larger than those in an LCD.
Since the EL display has such a large number of power supply lines and such a large number of control lines, the number of lines to be formed on the COF 22g is extremely large. In general, the number is tree times larger than that of the LCD.
Since the number of power supply lines and the number of control lines to be formed on the COF are large as illustrated in
If Distance A in the COF 22g is long, the range within which the driver output terminals 72 are formed is reduced. Alternatively, the long sides of the chips of the gate drivers IC 12 need to be lengthened. This results in increase in the size of the gate driver ICs 12, increasing the price of the gate driver ICs.
In order to reduce the number of COF lines 74 to be formed on the COF 22g, a means for forming array connection lines 54 as illustrated in
However, since the array connection lines 54 each intersects with the gate signal lines 17, if a pin hole exists at any of the intersection parts, the corresponding one of the array connection lines 54 and the gate signal lines 17 is short circuited. The EL display has a large number of gate signal lines 17. For this reason, the number of gate driver output terminals per gate driver IC 12 is also large. Accordingly, the number of intersection parts between the array connection lines 54 and the gate signal lines 17 is large, and thus short-circuit defects are likely to occur. In particular, the part on which the array connection lines 54 are formed is not provided with any protection cover, and is likely to be damaged mechanically. For this reason, short-circuit defects are likely to occur at the intersection parts.
In view of the above, the COFs 22g with the gate driver ICs 12 are mounted on and connected to the panel board 31, and, in the EL display having such a PCB-less configuration has the constraints below.
One of the constraints is (1) the lines 74 formed on each COF 22g cannot intersect with any line. The other is (2) the gate signal lines 17 on the panel board cannot intersect with the input signal lines and the power lines, or if the gate signal lines 17 on the panel board intersect with the input signal lines and the power lines, there is a high risk that any of the intersection parts is short-circuited, resulting in a significant reduction in the panel manufacturing yield.
As described above, it was difficult to provide an EL display having a panel board 31 on and to which COFs 22g with gate driver ICs 12 are mounted and connected and has such a PCB-less configuration.
In view of this, in embodiments below, descriptions are given of EL displays each having a reduced number of control lines formed in serial connection on a COF, and thereby reducing the cost and increasing the yield.
Hereinafter, displays according to embodiments are described with reference to
Each of
In the present disclosure, the drawings include omitted, magnified or reduced portions for help understanding or creation of the drawings. For example, a glass substrate 48 etc. are thin in the cross sectional view of a display panel illustrated in
Examples of omitted parts are indicated below. In the EL display in
On the light emission surface, a glareproof sheet having an uneven surface is formed or arranged in order to prevent natural light from being reflected on the light emission surface. However, such a glareproof sheet is not illustrated in
In the following descriptions, the connection terminal 75a corresponds to a first connection part in the present disclosure. The connection terminal 71 corresponds to a gate signal connection part in the present disclosure. The connection terminal 75b corresponds to a third connection part in the present disclosure. The driver output terminals 72 correspond to gate signal output terminals in the present disclosure. The driver input terminals 73a and 73b correspond to driver terminals in the present disclosure. The connection terminal 75c corresponds to a second connection part in the present disclosure. The COF lines 74a, 74b, and 74c correspond to serial connection lines in the present disclosure. The COF lines 74d and 74e correspond to terminal connection lines in the present disclosure. Input control lines 261 correspond to panel lines in the present disclosure.
Each of
A sealing substrate 30 and the panel board 31 are each, for example, a glass substrate. Each of the sealing substrate 30 and the panel board 31 may be formed using a silicon wafer, a metal substrate, a ceramic substrate, a plastic sheet (plate), or the like. In order to provide excellent heat dissipation, each of the sealing substrate 30 and the panel board 31 may of course be made of sapphire glass, or the like.
As illustrated in
The sealing substrate 30 has, for example, a cap shape. The sealing substrate 30 is a means for preventing or controlling infiltration of water content from outside, and the shape thereof is not limited to the cap shape. The sealing substrate 30 may be made of fusion glass. Alternatively, the sealing substrate 30 may be a compound of a resin, an inorganic material, or/and the like. The sealing substrate 30 is formed to be a thin film using vapor deposition technique or the like.
Temperature sensors (not illustrated) are formed or arranged in a space between the sealing substrate 30 and the panel board 31, on e.g. a surface of the sealing substrate 30. Depending on the results of outputs from these temperature sensors, the amplitudes of videos output from a source driver IC 14 etc. are varied. In addition, at the time when the panel is tested, the operation speeds of gate drivers IC 12 are adjusted based on the temperatures output from these temperature sensors. With the speed adjustment, appropriate operation speeds can be set.
A COF in the present disclosure is formed to absorb light by applying or forming a light absorbing composition or material to a surface of the COF, or bonding a sheet to the surface thereof. In addition, a heat dissipation plate is arranged or formed on the surfaces of driver ICs mounted on the COF, so as to dissipate heat from the driver ICs. In addition, a heat dissipation sheet and a heat dissipation plate are arranged or formed on the rear surface of the COF, so as to dissipate heat from the driver ICs.
In
Here, aperture rates of R, G, and B pixels may be varied. By varying the aperture rates, it is possible to vary the densities of currents flowing in the respective R, G, and B EL elements 15. By varying the densities of currents, it is possible to equalize deterioration speeds of the respective R, G, and B EL elements 15. By equalizing the deterioration speeds, the white balance of the EL display is retained.
The display in the present disclosure has pixels 16W of W (white), in addition to pixels of three primary colors of RGB. An excellent color peak luminance can be obtained by forming or arranging the pixels 16W. Furthermore, a high luminance display can be realized.
Each of the pixels 16 of the EL panel (EL display) in the present disclosure is configured to have switch transistors 11 and an EL element 15 as illustrated in
An insulation layer is formed between gate signal lines 17 etc. and color filters 33, but the insulation layer is not illustrated because no explanation thereof is necessary. This applies to the other embodiments.
As illustrated in
An insulation film 34 is formed on the color filters 33 (33R, 33G, and 33B). The insulation film 34 prevents EL films 41 etc. from deteriorating due to water content exuded from the color filters 33. The insulation film 34 functions also as a smoothing film.
Transistors 11 which constitute pixels 16 are formed on a layer above the color filters 33. A light blocking film 36 is formed on the transistors 11. As necessary, a light blocking film 36 is formed on a layer below the transistors 11, and a layer below or above gate driver circuits. The anode electrodes 40 and the transistors 11 are connected at connection parts 37.
The light blocking film 36 is formed with a metal thin film made of chromium or the like, to have a film thickness ranging from 50 nm to 150 nm inclusive. A thin light blocking film 36 provides a small light blocking effect, while a thick light blocking film 36 makes it difficult to pattern transistors 11 in a layer above the light blocking film 36 due to unevenness of the light blocking film 36.
By arranging or forming source signal lines 18, the anode electrodes 40 or cathode electrodes above the gate signal lines 17, electric fields from the source signal lines 18 and the gate signal lines 17 are blocked by the anode electrodes 40 or the cathode electrodes. With this blocking, it is possible to reduce noise in image display.
An insulation film or an insulation film (planarizing film) 34 made of an acrylic material is formed to insulate the source signal lines 18 and the gate signal lines 17, and the anode electrodes 40 are formed on the insulation film 34.
Such a configuration in which the anode electrodes 40 are overlapped at least partly above the gate signal lines 17 etc. is referred to as a high aperture (HA) structure. This configuration reduces unnecessary interference light etc. and realizes an excellent light emission state.
The insulation film (planarizing film) 34 functions also as an inter-layer insulation film. The insulation film (planarizing film) 34 reduces parasitic capacitances of the gate signal lines 17 etc. and the anode electrodes 40. In order to reduce the parasitic capacitances, the insulation film (planarizing film) 34 is formed to have a thickness of 0.4 μm or larger. However, a thin insulation film 34 increases connection errors at the connection parts 37. For this reason, the insulation film 34 is configured or formed to have a thickness of 2.0 μm or smaller.
An insulation film 34 having a thickness of 0.4 μm or smaller causes an inter-layer insulation error, reducing the yield. An insulation film 34 having a thickness of 2.0 μm or larger makes it difficult to form contact connection parts, which causes insufficient contact, reducing the yield.
As the anode electrodes 40 of the pixels 16, transparent electrodes made of ITO, IGZO, IZO, TAOS, or the like can be used.
The parasitic capacitances occurring between the anode electrodes 40 and the gate signal lines 17 affect rise and fall times of the gate signal lines 17. The gate signal lines 17 for which a fast response is required is driven by the gate driver ICs 12 connected from outside. An anode voltage, a cathode voltage, etc. are supplied from rings (not illustrated) reinforced using reinforcement lines (not illustrated) of the COF 22. Accordingly, falls of voltages such as the anode voltages are small irrespective of the positions in the display screen.
A light scattering film 38 contributes to increase in light emitted from the panel. Light generated from one of the EL films 41 of the EL elements enters the panel board 31 (Trajectory a) and emitted from the panel board 31. However, when the light is incident on the light emission surface of the panel board 31 with a light incident angle larger than a critical angle, the incident light is reflected and returns to the EL film 41 (a trajectory b).
The light scattering film 38 is preferably formed to have a film thickness ranging from 0.1 (μm) to 1.5 (μm) inclusive, depending on a light diffusion performance.
It is to be noted that a circularly polarizing plate (circularly polarizing film) 32 is arranged on the light emission surface of the panel board 31. An integrated one of a polarizing plate and a phase film is referred to as a circularly polarizing plate (circularly polarizing film).
In a conventional EL display panel, the light having Trajectory b is diffused on the EL display panel and is absorbed therein. Accordingly, the light having Trajectory b is absorbed therein, and is not emitted from the panel to outside.
On the EL display panel according to the present disclosure, the light having Trajectory b is diffused on the light scattering film 38, and the trajectory of the light changes. As the result of the change in the trajectory, the light whose angle is reduced at or below the critical angle on the light emission surface of the panel is emitted from the panel (Trajectory c).
In this way, the trajectory of the light reflected on the boundary face of the panel is changed to be emitted from the panel to outside. Accordingly, the EL display panel has a high light utilization rate, and realizes a high luminance display.
Although the light scattering film 38 is formed above the insulation film 34 in the above non-limiting example, the light scattering film 38 may be formed in a layer below the insulation film 34.
In the peripheral parts of the color filters 33, a black matrix (BM) may be formed. Preferably, the black matrix (BM) is configured with a light absorbing film having a light absorbing property. This is because halation light in the panel can be reduced.
Examples of materials for use as a light absorbing film includes a material obtained by including carbon in an organic material such as acrylic resin, a material obtained by dispersing a black dye or a pigment in an organic resin, and a material such as a color filter obtained by dyeing using gelatin or casein using a block acid dye.
Alternatively, a material obtained using a fluoran dye representing a black color may be used, or a black color obtained by mixing a green dye and a red dye can also be used. Other examples include a PrMnO3 film formed by sputtering, a phthalocyanine film formed by plasma polymerization.
Ribs (banks) 39 are formed in the peripheral parts of the anode electrodes 40. Ribs (banks) are also used as ribs (banks) 39 for use in mask deposition for ELs. The ribs (banks) 39 are used as contact parts of deposition masks to form EL films 41 (41R, 41G, 41B).
On the EL films 41, cathode electrodes 43 made of a metal material is formed. Examples of materials for use as the cathode electrodes 43 include silver (Ag), aluminum (Al), magnesium (Mg), calcium (Ca), or an alloy containing one or more of these metals. An example is a composition of Mg and Ag. In addition, it is also possible to use transparent electrodes made of ITO, IGZO, IZO, TAOS, or the like, depending on the structure of each EL element 15.
Needless to say, the above embodiments are also applicable to other embodiments in the present disclosure. In addition, the above embodiments can of course be combined with other embodiments.
As illustrated in
In addition, in the EL display of “top light extraction”, a low resistance line 44 made of a metal thin film in a layer above or below the cathode electrodes. Examples of compositions for use as the low resistance line 44 are the same as in a black matrix (BM) of a liquid crystal display panel. For example, chromium (Cr), aluminium (Al), titanium (Ti), and copper (Cu) may be used. Other examples include a three layer configuration of Ti, Cu, and Ti, and a three layer composition of Ti, Al, and Ti. Alternatively, an alloy of metal materials may be formed. Needless to say, the configurations, methods, and other details are also applicable to rings (not illustrated).
A thicker BM film is easy to have a reduced resistance and preferable. However, considering an unevenness problem, the film thickness thereof is set to be a range from 200 (nm) to 800 (nm) inclusive. The BM 44 is formed corresponding to the position of pixels 16 and the anode electrodes 40. In other words, the BM 44 is mainly formed between pixel electrodes.
It is to be noted that a BM 44 may be formed for each of groups of R, G, B, and (W) pixels, or for each of a plurality of groups of R, G, B, and (W) pixels. The BM 44 may be formed on the layer above the gate driver ICs 12. This is because the BM 44 functions as a light blocking film, to prevent operation errors of the gate driver ICs 12.
Although the BM 44 has been described above, the BM 44 is different from an BM in LCD because there is no need to form an BM in an organic EL. A low resistance line (BM) 44 does not always need to be formed on a layer above optically transparent electrodes, and may be formed on a layer below optically transparent electrodes. Alternatively, a low resistance line (BM) 44 may be stacked with cathode electrodes and anode electrodes.
In addition, preferably, a sheet resistance value or a resistance value per unit length of an BM 44 varies corresponding to the part of a display screen 25. A voltage decreases significantly at the center part or a part with many voltage supply points of the display screen 25. For this reason, with increase in the distances from the voltage supply points, the BM 44 is made wider or the resistance value is reduced by thickening the BM 44. The resistance value or the sheet resistance value of the BM 44 is reduced more significantly with decrease in the distance to the center part of the display screen 25 by widening or thickening the BM 44.
An BM 44 can be formed thick when designing a panel. An BM 44 can be formed thick at the part corresponding to the center part of a display screen 25 by depositing the material of the BM 44 in a distribution. For example, a concentric circle like distribution of film thicknesses is generated.
A glass substrate 48 is bonded with a bonding layer 47. The glass substrate 48 may be a thin sealing film. Alternatively, a glass substrate 48 may be configured as a sealing film.
When using a sealing film (thin sealing film) as a replacement for the glass substrate 48, for example, a DLC film with diamond like carbon deposited thereon may be used. This film has a high moisture proof performance. This film is used as a sealing film.
Needless to say, the DLC film or the like may be directly deposited on the surfaces of the cathode electrodes 43. Alternatively, a thin sealing film may be formed by stacking a thin resin film and a thin metal film.
A cathode voltage Vss is applied to the cathode terminal of the EL element 15. An anode voltage Vdd is applied to the source terminal of the driver transistor 11a. There is a relationship of the anode voltage Vdd>the cathode voltage Vss.
Here, the anode voltage is variable based on a maximum amplitude of a video signal to be output by a source driver IC 14.
In addition, by turning on or off the switch transistor 11d, a duty drive is performed.
When an on voltage is applied to a gate signal line 17b, the switch transistor 11d is turned on, and a current for light emission is supplied from the driver transistor 11a to the EL element 15. The EL element 15 emits light based on the magnitude of the current for light emission. The magnitude of the current for light emission is determined by applying a video signal applied to a source signal line 18 to the pixel 16a using the switch transistor 11b.
A first terminal of a capacitor 19a is connected to the gate terminal of the driver transistor 11a, and the first terminal of the capacitor 19a is connected to the drain terminal of the switch transistor 11b. The source terminal of the switch transistor 11b is connected to the source signal line 18. The applied on voltage of the gate signal line 17a turns on the switch transistor 11a, and a video signal Vs (voltage, current) applied to the source signal line 18 is applied to the pixel 16a.
The first terminal of the capacitor 19a is connected to the drain terminal of the switch transistor 11b, and the second terminal is connected to the anode electrode and receives an anode voltage Vdd.
Although the second terminal of the capacitor 19a is connected to the anode electrode 40 and receives the anode voltage Vdd, this is a non-limiting example. For example, another arbitrary direct voltage is applied thereto.
Although the source terminal of the driver transistor 11a is connected to the anode electrode 40 and receives the anode voltage Vdd, this is a non-limiting example. For example, another arbitrary direct voltage is applied thereto. In other words, the second terminal of the capacitor 19a and the source terminal of the driver transistor 11a may be connected to terminals having different potentials.
A gate driver IC 12a and a gate driver IC 12b are connected to the gate signal line 17a which drives the switch transistor 11b for applying the pixel 16a with a video signal Vs. As an example, the gate driver IC 12a is arranged left of the display screen 25, and the gate driver IC 12b is arranged right of the display screen 25 (refer to
As illustrated in
As illustrated in
Each group of one of shift resisters 51 (51a, 51b) and the output buffer 52 (52a, 52b) is referred to as the gate signal output circuit 53 (53a, 53b).
The reason why two gate driver ICs 12 (12a, 12b) are arranged for a gate signal line 17a is described below.
The gate signal line 17a is connected to the switch transistor 11b. The switch transistor 11b is a transistor for writing a video signal to the pixel 16a, and the switch transistor 11b needs to perform a fast on and off operation (high slew rate operation). The gate signal line 17a performs the high slew rate operation by driving the two gate driver ICs 12 (12a, 12b).
Although the two gate driver ICs 12 are connected to the gate signal line 17 in the above embodiments, the present disclosure is not limited thereto. As illustrated in
The gate signal line 17a drives the two gate driver ICs (12a, 12b), and thereby eliminating a luminance slope at right and left sides and the center of a display screen 25. Even when the load capacity of the gate signal line 17a is large, it is possible to turn on or off the switch transistor 11b effectively.
The gate driver IC 12a is connected to a gate signal line 17b. In other words, the gate signal line 17b is connected to the output buffer 52.
The gate signal line 17b is connected to a switch transistor 11d. The switch transistor 11d has a function for switching on or off a drive current to be flown from the driver transistor 11a to an EL element 15. The on and off operation for causing a current to flow to the EL element 15 can be performed only at a low slew rate.
Accordingly, the gate signal line 17b can obtain sufficient performances by driving the gate driver IC 12a (the output buffer 52).
In
In the embodiment in
In
Accordingly, the speed of the shift clock of the gate driver IC 12b is the half of the speed of the shift clock of the gate driver IC 12a.
SEL terminals which are control terminals for logic setting are arranged or formed between driver input terminals 73b which apply a voltage to the control terminals such as CLk to which serial connection lines are connected and the driver output terminals 72.
In this embodiment, each of the control terminals which set logics is arranged or formed between (i) corresponding one of the driver input terminals 73a to which the serial connection lines are connected or corresponding one of the driver input terminals 73b to which the serial connection lines are connected and (ii) the driver output terminals 72. However, this configuration is a non-limiting example. A COF 22g has only a single wiring layer, and thus it is impossible to form intersection parts in COF lines 74 (74a to 74e). Accordingly, the positions of terminals of the driver ICs can be represented as the connection positions in the COF 22g.
For example, in
Accordingly, in the present disclosure, the connection terminals 75c of the COF 22g for the Buf (Buf1, Buf2) terminals which are logic setting terminals are arranged between or connected to the connection terminals 75a and the connection terminals 71. In addition, in the present disclosure, the SEL (SEL1, SEL2) terminals which are logic setting terminals are arranged between or connected to the connection terminals 75b and the connection terminals 71. In addition, the COF line 74a, a COF line 74c, and the COF line 74b (not illustrated) constitute a group of serial connection lines.
In the EL display in
In the pixel 16 in
In
A first terminal of a switch transistor 11e is connected to an electrode or a line to which a reset voltage Vref is applied, and a second terminal of the switch transistor 11e is connected to the gate terminal of the driver transistor 11a. The gate terminal of the switch transistor 11e is connected to the gate signal line 17c.
A first terminal of the switch transistor 11b which applies the pixel 16 with a video signal is connected to a source line 18, and a second terminal of the switch transistor 11b is connected to the gate terminal of the driver transistor 11a. The gate terminal of the switch transistor 11b is connected to the gate signal line 17a.
A first terminal of a switch transistor 11c is connected to an electrode or a line to which an initial voltage Vini is applied, and a second terminal of the switch transistor 11a is connected to a second terminal of the drive transistor 11a. The gate terminal of the switch transistor 11c is connected to the gate signal line 17d.
A first terminal of an EL element 15 is connected to a second terminal of the driver transistor 11a, and a second terminal of the EL element 15 is connected to an electrode or a line to which a cathode voltage Vss is applied.
A first terminal of a capacitor 19 is connected to the gate terminal of the driver transistor 11a, and a second terminal of the capacitor 19 is connected to a second terminal of the driver transistor 11a.
For at least one of the switch transistors 11b or a switch transistor 11e, a multi-gate (dual-gate or above) structure is employed, and a lightly doped drain (LDD) configuration is combined. With this configuration, an off-leak is controlled, an excellent contrast can be obtained, and offset cancelling can be performed. In addition, an excellent high luminance display and image display can be realized.
The gate signal line 17a and the gate signal line 17c are driven at both sides by the gate driver IC 12a and the gate driver IC 12b. In addition, the gate signal line 17c and the gate signal line 17d are driven at one side by the gate driver IC 12a.
In
The following are connected or arranged to a gate signal output circuit 53a: a data input terminal (Dat1) which inputs data to a shift register (not illustrated); an enable input terminal (Enb1) which enables or disables output from the shift register (not illustrated) (an on voltage is output to a gate signal line, and an off voltage is output to the gate signal line); and a clock input terminal (Clk1) which inputs a clock for shifting data in the shift register (not illustrated).
The following are connected or arranged to the gate signal output circuit 53b: a data input terminal (Dat2) which inputs data to a shift register (not illustrated); an enable input terminal (Enb2) which enables or disables output from the shift register (not illustrated) (an on voltage is output to a gate signal line when the output is enabled, and an off voltage is output to the gate signal line when the output is disabled); and a clock input terminal (Clk2) which inputs a clock for shifting data in the shift register (not illustrated).
On the flexible board 22g, COF lines 74 (74a, 74b, 74c, 74d, and 74e) are formed. A signal or a voltage is applied to the gate driver IC 12 from the driver input terminals 73 (73a, 73B) via the COF lines 74a, 74b, and 74c.
As illustrated in
The SEL terminals and the voltage application terminals Voff (Viff1, Voff2) are arranged or formed at an output side of the gate driver IC 12.
The connection terminals 75c of logic setting terminals such as SEL (SEL1, SEL 2) terminals are arranged or formed between connection terminals 71 and driver input terminals (73b).
The connection terminals 75c receive predetermined voltages such as logic voltages from the logic terminals SEL1 and SEL2. One of the logic voltages is applied to an operation terminal 76 of the gate driver IC 12 via a line 74d (hereinafter referred to as a “terminal connection line”) which connects a point inside the COF 22g and a connection terminal 71.
Signal output from the gate driver IC 12 are output from the connection terminals 71 via driver output terminals 72 and COF lines 74e. Gate signal lines 17 are connected to the connection terminals 71.
As illustrated in
As illustrated in
At the input stages for the control signals such as Dat1, Enb1, Clk1, Dat2, Enb2, Clk2, input circuits such as Schmidt circuit and a hysteresis circuit are formed. Each of gate signal output circuits 53 (53a, 53b) is configured to latch input signals. For example, in the Clk2, a clock input to a connection terminal 75a is applied to the driver input terminal 73a via a COF line 74a. The clock signal applied to the driver input terminal 73a is subjected to noise removal at the Schmidt circuit of the gate signal output circuit 53b, and latched by a latch circuit (not illustrated). The latched clock data is output to the driver input terminal 73b via a line (not illustrated) formed inside the gate signal output circuit 53a. The clock data Clk2 output from the driver input terminal 73b is output from the connection terminal 75b via a COF line 74c.
In
When a line connecting the driver input terminal 73a and the driver input terminal 73b is a power supply line such as a Von voltage line and a Voff voltage line, the COF line 74b functions as a bypass line. The COF line 74b reduces an impedance of a power supply line, and increases stable supply of power.
As illustrated in each of
As illustrated in each of
Control signals such as the clock Clk, data Dat, enable Enb are transmitted via the internal line 262 (262a to 262c). COF lines 74c transmit an on voltage Von, an off voltage Voff, a logic voltage Vcc, and a ground voltage Vgg.
Since the internal lines 262 (262a to 262c) transmit the control signals such as the clock Clk, data Dat, enable Enb, the COF 22g does not require formation or arrangement of the COF lines 74c for control signal lines. For this reason, Distance A and Distance B in
The lines for transmitting the control signals such as the clock Clk, data Dat, enable Enb are configured to arrange the bi-directional buffer 271 (271a, 271b) in the internal lines 262 (262a to 262c), and the bi-directional buffer 271 supports hysteresis input. Accordingly, a waveform is adjusted to adjust a delay time. For this reason, synchronous control of gate signal lines 17 on a display screen is easy to realize. Since synchronization with a delay circuit 485 in
In addition, driver input terminals S3b and S2b are electrically connected through a COF line 74f1. The driver input terminals S2b and S3b are electrically connected through a COF line 74f2.
With the configuration, a control signal can be supplied to the plurality of driver input terminals S2b and S3b by a COF line 74a1 which supplies a control signal to a gate driver IC 12. In addition, a voltage can be supplied to the driver input terminals S2b and S3b by a COF line 74c1 which supplies a control signal to a gate driver IC 12.
In an EL display illustrated in
An on voltage and an off voltage to be applied to gate signal lines 17 are output from driver output terminals 72 of the gate driver IC 12. The driver output terminals 72 and connection terminals 71 are electrically connected through COF lines 74e formed in a COF 22g.
Lines which connect between two or more connection terminals 75 (75a, 75b) such as a clock CLK terminal, a data Dat terminal, on a Von voltage terminal are connected to a driver input terminal 73b and a driver input terminal 73a (the lines are hereinafter referred to as “serial connection lines”, and are for example, in
The driver input terminal 73a and the connection terminal 75a are electrically connected through the COF line 74a formed in the COF 22g. In addition, the driver input terminal 73b and a connection terminal 75b are electrically connected through the COF line 74c formed in a COF 22g.
As illustrated in each of
Operation terminals 76 of a gate driver IC 12 are arranged or formed between (i) driver output terminals 72 and driver input terminals 73a, or (ii) the driver output terminals 72 and driver input terminals 73b. Alternatively, operation terminals 76 are arranged or formed between the both, that is, between (i) driver output terminals 72 and driver input terminals 73a, or (ii) the driver output terminals 72 and driver input terminals 73b.
The following are formed in the COF 22g: COF connection lines (74a, 74b, 74c) to be serial connection lines are formed; and a COF connection line 74e for transmitting an on voltage (Von) and off voltages (Voff1, Voff2) from the gate driver IC 12 to the gate signal line 17.
A COF connection line 74d is arranged or formed either between a COF connection line 74e and a COF connection line 74c, or between a COF connection line 74a and the COF connection line 74e. Thus, the COF connection line 74d does not have any intersection parts with the COF connection line 74e, the COF connection line 74a, the COF connection line 74b, and the COF connection line 74c. Accordingly, even when the COF 22g is wired at one side, the COF connection line 74d can be easily formed.
Furthermore, it is easy to layout a pattern on the COF connection line 74d from the panel side (on which the panel lines 91 (91a, 91b) are formed) so that a voltage can be applied to the COF lines 74d.
As described above, the terminals (such as the SEL terminals) connected to the COF connection line 74d do not need to be connected in serial connection. For this reason, it is possible to reduce the number of COF lines 74a, 74b, and 74c to be the serial connection lines.
With the configuration disclosed above, it is possible to shorten or reduce Distance B, Distance A, Distance C, and Distance D explained with reference to
In
As illustrated in
On a panel board 31, panel lines 91 (91a (91a1), 91b(91b1)) are formed or patterned. The panel lines 91 are power supply lines such as an on voltage Von, off voltages Voff, an anode voltage Vdd, and a cathode voltage Vss, and control lines such as Clk, Enb, etc.
The Von denotes an on voltage to be applied to the gate signal line 17, Voff denotes an off voltage to be applied to the gate signal line 17, Vcc is a ground voltage Vgg of the power supply of a logic circuit to be used in the gate driver IC 12, and Vgg is a ground voltage of the logic terminal.
The panel line 91a1 located innermost of the panel line 91a and the panel line 91b1 located innermost of the panel line 91b are lines to which a voltage Vcc or a voltage Vgg is applied. The voltage Vcc or the voltage Vgg means a setting voltage of the logic terminal in a broad sense.
However, a voltage to be applied to the panel lines 91a1 and 91a2 may be a voltage Von or a voltage Voff. In other words, the voltage to be applied may be a constant voltage fixed in a certain period. The voltage Von or the voltage Voff is subject to a level shift process or a level down process at a level transform circuit in the driver IC 12, and the resulting voltage can be used as a voltage level signal for logic setting of the gate driver IC 12.
An input control line 261a branches from the panel line 91a1. The input control line 261a is connected to a connection terminal 75c of a COF 22g. The connection terminal 75c is a terminal to which a control voltage at a logic level is to be applied. The control voltage at the logic level is a signal voltage for logic setting. For example, a voltage at or above a first predetermined voltage is assumed to be Level H of the logic, and a voltage below the first predetermined voltage is assumed to be Level L. An operation terminal 76 and the connection terminal 75c of the gate driver IC 12 are electrically connected to the COF connection line 74d.
An input control line 261b branches from the panel line 91b1. The input control line 261b is connected to the connection terminal 75c of the COF 22g. The operation terminal 76 and the connection terminal 75c of the gate driver IC 12 are electrically connected to the COF connection line 74d. The operation terminal 76 is arranged between the connection terminal 71 of the gate signal line 17 and a driver input terminal 73a of the gate driver IC 12.
The panel line 91a is connected to the COF line 74a of the COF 22g through a connection terminal 75a at the upper part of the drawing sheet. The COF line 74a is connected to the driver input terminal 73a. The driver input terminal 73a and a driver input terminal 73b are electrically connected through the COF line 74b.
As described above, on the gate driver IC 12, a plurality of driver input terminals 73 (73a, 73b) are arranged or formed for a voltage of one kind and a control signal of one kind.
The driver input terminal 73b and the connection terminal 75b are electrically connected through the COF line 74c. The connection terminal 75b is connected to the panel line 91b.
As described above, they are formed or arranged in serial connection to the panel line 91a, the connection terminal 75a, the COF line 74a, the driver input terminal 73a, the COF line 74b, the driver input terminal 73b, the COF line 74c, the connection terminal 75b, and the panel line 91b. In other words, they are connected by the serial connection lines.
A voltage and a control signal from a driver circuit (not illustrated) are applied from a voltage and signal input unit 101 to a panel substrate 31, and are then applied to the flexible board 22g1 through a panel line 91a, and are then applied to a driver input terminal 73a of a gate driver IC 12a. The voltage and signal input unit 101 is connected to a source print board 23. The voltage and the signal are supplied from the source print board 23 to the COF 22g through the voltage and signal input unit 101.
The voltage and the control signal from the flexible board 22g1 are applied to the flexible board (COF) 22g2 through the panel line 91b, and are then applied to a gate driver IC 12b. The voltage and the control signal from the flexible board (COF) 22g2 are applied to a next flexible board (COF) 22g3 (not illustrated) through a panel line 91c. As described above, the voltage and the control signal are connected in serial connection to a plurality of flexible boards (COF) 22g through the panel line 91b.
A voltage Vcc (a logic voltage of a driver IC) is applied to input control lines 261. In other words, a logic voltage (normally, a voltage Vcc or Vgg) to be applied to the connection terminal 75c is applied to the panel line 91a. The connection terminal 75c and an operation terminal 76 are electrically connected through a connection line 74d. A logic voltage is applied to lines (91a1, 91b1) located innermost of the panel line 91. The logic voltage is applied to an operation terminal 76 connected to the COF connection line 74d.
As illustrated in
In a state where one or more of the SEL terminals is open (no voltage is applied thereto), the logic is L. In the case of L, a two-value drive of gate voltages (
More specifically, an array pattern is laid out so that a voltage is applied to operation terminals 76 through the input control lines 261, or a pattern (not wire-connected) is laid out so that the operation terminals 76 is open without applying a voltage to the operation terminals 76. With this configuration, it is possible to determine logic levels of the SEL terminals (SEL1 to SEL4). Based on these logic levels, it is possible to set or determine which one of a two-value drive of gate voltages or a three-value drive of gate voltages is performed by each of gate signal output circuits 53 (53a, 53b, 53c, 53d).
As illustrated in each of
The internal lines 262 constitute an internal line pattern of the gate driver IC 12. It electrically connects the driver input terminal 73a and the driver input terminal 73b.
In each of the gate signal output circuits 53 (53a, 53b, 53c, 53d), the following are arranged or formed: an input (application) terminal of an on voltage (Von); a data input (Dat) terminal; an enable (Enb) terminal; and a clock (Clk) terminal. A terminal (UD terminal) which inverses a vertical scanning direction is shared by these four gate signal output circuits 53.
These SEL terminals are arranged corresponding to the respective gate signal output circuits 53 (53a, 53b, 53c, 53d). Each of the SEL terminals is a terminal for setting or operating a two-value drive of gate voltages and a three-value drive of gate voltages. In a broad sense, the SEL terminals are terminals for switching or controlling drive modes of the gate signal output circuits 53 (53a, 53b, 53c, 53d). Accordingly, the drive methods are not limited to the two-value drive of gate voltages and the three-value drive of gate voltages. For example, each of the SEL terminals may be a terminal for setting a selection of one of the four value voltages which are a voltage Von1, a voltage Von2, a voltage Voff1, and a voltage Voff2.
The gate signal output circuit 53a is set to the three-value drive of gate voltages by setting the SEL1 terminal to Logic “H”, and the gate signal output circuit 53b is set to the three-value drive of gate voltages by setting the SEL2 terminal to Logic “H”. The gate signal output circuit 53c is set to the three-value drive of gate voltages by setting a SEL3 terminal to Logic “H”, and the gate signal output circuit 53d is set to the three-value drive of gate voltages by setting a SEL4 terminal to Logic “H”. It is to be noted that the settings of Logic “H” and “L” may be inversed.
The one for which the three-value drive of gate voltages is performed is 17a gate signal line a connected to a transistor for writing a video signal to a pixel 16. Even when a plurality of gate signal lines are formed or arranged in the pixel 16, the gate signal line connected to the transistor for applying the video signal is identified solely as a gate signal line 17a. In other words, even when a plurality of gate signal driver circuits are formed in the gate driver IC 12, one of them can be set to be subject to the three-value drive of gate voltages, and the other gate signal driver circuit may be subject to the the two-value drive of gate voltages.
For example, when eight gate signal driver circuits are arranged or formed on the gate driver IC 12, the number of SEL terminals may be three, and a decoder (3-8 decoder) for selecting one of eight 3-bit gate signal line driver circuits may be configured.
As described above, in the present disclosure, the SEL terminals make it possible to switch between the two-value drive of gate voltages and the three-value drive of gate voltages independently or indivisualy for the gate signal output circuits 53 (53a, 53b, 53c, 53d) corresponding respectively to the gate signal lines.
In the present disclosure, the gate signal line 17 connected to the transistor for writing a video signal is driven by a both-side drive (performed by two gate driver ICs 12 arranged right and left of a display screen 25). The other gate signal lines for which fast slew rate is not required is driven by a one-side drive (performed by one of the gate driver ICs 12 arranged right and left of the display screen 25).
In each of the EL display illustrated in
The EL display according to this embodiment connects control signal lines for logic control, etc. from the panel side (on which the panel line 91 is formed) to the operation terminals 76. With this configuration, the number of COF lines 74 (74a, 74b, 74c) is reduced. In a conventional EL display, all of control signal lines and power supply lines need to be formed in serial connection. Thus, as illustrated in
In addition, input control lines 261 are formed to branch from lines to which predetermined voltages (e.g. a logic voltage Vcc, a ground voltage Vgg) are applied from the panel lines 91 (91a, 91b). In a configuration according to a wiring layout design for forming an array pattern, voltages corresponding to logics to be set are applied to the operation terminals 76. With this configuration, Distance C for forming the panel lines 91 (91a, 91b) in
Although the above descriptions have been given of the gate driver IC 12 and the COF 22g, needless to say, the same descriptions can also apply to the source driver IC 14 and the COF 22s.
Of course, the above embodiments are also applicable to other embodiments in the present disclosure. In addition, the above embodiments can, not to mention, be combined with other embodiments.
SEL terminals (for setting a two-value drive of gate voltages and a three-value drive of gate voltages of a gate signal output circuit 53) that are control terminals for logic setting are arranged or formed between driver input terminals 73b and the driver output terminals 72, to which serial connection lines are connected.
A UD terminal that is a control terminal for logic setting is arranged or formed between driver input terminals 73b apply voltages (a voltage Von, a voltage Voff) and the driver output terminals 72 to which serial connection lines are connected.
Likewise, when the gate signal output circuit 53b performs a three-value drive of gate voltages, a voltage VonB, a voltage Voff1b, and a voltage Voff2b are output. When the gate signal output circuit 53c performs a three-value drive of gate voltages, a voltage VonC, a voltage Voff1c, and a voltage Voff2c are output. When the gate signal output circuit 53d performs a three-value drive of gate voltages, a voltage VonD, a voltage Voff1d, and a voltage Voff2d are output.
The other details are the same as in
In addition, a COF line 74a, a COF line 74c (not illustrated), and a COF line 74b constitute a group of serial connection lines. The connection terminal 75a of one of the SEL terminals for logic setting or operation setting is connected or arranged between the connection terminals 71 of the gate signal lines 17 and the connection terminals 75a. The connection terminal 75c of the UD terminal for logic setting or operation setting is connected or arranged between the connection terminals 71 of the gate signal lines 17 and the connection terminals 75b. When a logic voltage is applied to the operation terminals 76, or a pull-up or a pull-down is performed in the gate driver IC C12, no voltage is applied to the operation terminals 76 so as to keep the operation terminals 76 open.
An input control line 261b branches from a panel line 91a2 of the panel line 91a. It is assumed that, for example, a logic voltage Vgg is applied to the input control line 261b as a branch. The input control line 261b is connected to operation terminals 76b.
With this configuration, the operation terminals 76b to which the ground voltage Vgg is applied have a logic level of L. The operation terminals 76a to which the logic voltage Vcc is applied have a logic level of H.
The operation terminals 76 (76a, 76b) are terminals for defining or setting modes, operations, and actions of gate signal output circuits 53 (53a to 53d) in a gate driver IC 12. The logic levels (H, L) applied to the operation terminals 76 set actions of the gate driver IC 12.
In the configuration of
In
The voltage Von applied to the driver input terminal 73c is used as a voltage of Logic H. The voltage Voff applied to the driver input terminal 73b is used as a voltage of Logic L.
The driver input terminal 73c is connected to an internal line 262c. The driver input terminal 73b is connected to an internal line 262b. The internal line 262c becomes a voltage of Logic (logic level) H, and is output to terminals H4 to H1 of a gate driver IC 12. An internal line 262b becomes a voltage of Logic (logic level) L, and is output to terminals L5 to L1 of the gate driver IC 12. Operation terminals C8 to C1 are the operation terminals 76.
As a connection denoted as “A” in
Likewise, as a connection denoted as “B” in
As a connection denoted as “C” in
As a connection denoted as “D” in
As described above, an EL display according to this embodiment is configured to perform a method for setting the logic levels of the operation terminals 76 through the internal lines 262 (262b, 262c).
In other words, in each of the embodiments illustrated in
As illustrated in each of
Similarly, for example, the driver input terminals 73 (73b1, 73b2) are formed as input terminals of two driver input terminals, 73 and the driver input terminals 73b1 and the driver input terminals 73b2 are electrically connected through a corresponding one of the internal lines 262.
In addition, some of the driver input terminals 73a2 are electrically connected through a COF line 74f1. In addition, some of the driver input terminals 73a1 are electrically connected through a COF line 74f2. Similarly, some of the driver input terminals 73b2 are electrically connected through a COF line 74f1. Some of the driver input terminals 73b1 are electrically connected through a COF line 74f2.
With this configuration, a plurality of Von1 voltages can be supplied to the driver input terminals 73a1 and 73a2 through a COF line 74a1 which supplies the voltages Von1 to the gate driver IC 12. With this configuration, a plurality of voltages Von2 can be supplied to the driver input terminals 73a2 and 73a1 through a COF line 74a2 which supplies the voltages Von2 to the gate driver IC 12.
In addition, a plurality of voltages Von1 can be supplied to the driver input terminals 73b1 and 73b2 through a COF line 74c1 which supplies the voltages Von1 to the gate driver IC 12. In addition, a plurality of voltages Von2 can be supplied to the driver input terminals 73b1 and 73b2 through a COF line 74b2 which supplies the voltages Von2 to the gate driver IC 12.
Although this embodiment has been described regarding the driver input terminals, the present disclosure is not limited thereto. For example, the embodiment in
Although the above embodiments have been described regarding the control signals of the driver input terminals, the present disclosure is not limited thereto. For example, voltage supply lines explained in
Needless to say, the above embodiments are also applicable to other embodiments in the present disclosure. Of course, the above embodiments can be combined with other embodiments.
An output waveform in
As illustrated in
The two-value drive of gate voltages (
The voltage Von is a voltage for turning on a transistor 11 of a pixel 16. The voltages Voff1 and Voff2 are voltages for turning off the transistor 11 of the pixel 16. More specifically, the voltage Von ranges from 15 (V) to 30 (V) inclusive. The voltage Voff2 ranges from −15 (V) to −8 (V) inclusive. The voltage Voff1 ranges from −8 (V) to −3 (V) inclusive.
In each of
Each of
As illustrated in
As illustrated in
As in the case of the voltages Von (Von1, Von2), voltages Voff (Voff1, Voff2) can also be varied or adjusted by the respective gate signal output circuits 53 (53a, 53b). These configurations are the same as in
Although the voltages Von (Von1, Von2) and voltages Voff (Voff1, Voff2) can be varied or adjusted by the respective gate signal output circuits 53 (53a, 53b) in each of
The application period Ta of the voltage Von is an nH period (n is an integer of 1 or larger) in which synchronization with a Clk signal is realized. The three-value drive of gate voltages in
The voltage Voff2 is applied in the 1 H period (Period Tb) in order to quickly stop selecting (turning off) pixels selected for being applied with a video signal, after writing the video signal thereto. In addition, the voltage Voff1 is retained (in Period Tc) in order to prevent a deep voltage (Voff2) from being applied to the gate terminal of the transistors 11 so as to prevent a change such as a Vt shift from occurring and changing a transistor characteristic.
As illustrated in
As illustrated in
After an application period of the voltage Von, the voltage Voff2 is applied in a 1 H period or a period (Period Tb) shorter than the 1 H period. After an application period of the voltage Voff2, the voltage Voff1 is applied to the gate signal line 17 corresponding to the selected pixel row, and the gate signal line is retained at the voltage Voff1 in a period (Period Tc) before a next frame period in which a voltage Von is applied.
In the case of the two-value drive of gate voltages (a normal drive of gate voltages), there is no Period Tb as illustrated in
After an application period of the voltage Von, the voltage Voff2 is applied in a 1 H period or in a period shorter than the 1 H period. After an application period of the voltage Voff2, the voltage Voff1 is applied to the gate signal line 17 corresponding to the selected pixel row, and the gate signal line 17 is retained at the voltage Voff1 in a period before a next frame period in which a voltage Von is applied.
It is to be noted that the two-value drive of gate voltages and the three-value drive of gate voltages are set by a logic signal to be applied to SEL (SEL1, SEL2) terminals. As illustrated in each of FIGS. 20A and 20B, a gate signal output circuit 53 is set to the mode of two-value drive of gate voltages when the logic voltage to be applied to the SEL (SEL1, SEL2) terminals is “L”. When the logic voltage to be applied to the SEL (SEL1, SEL2) terminals is “H”, the gate signal output circuit 53 is set to the mode of three-value drive of gate voltages.
As illustrated in
In the t1 period in the two-value drive of gate voltages, the transistors connected to the gate signal lines 17 (17a, 17b) are not in a completely off state, and thus, for example, video signals written to the pixels 16 leak. On the other hand, in the t1 period in the three-value drive of gate voltages, since the applied voltage Voff2 reduces, to t2, the period for the transition from the Von voltage level to the Voff1 voltage level, no video signals written to the pixels 16 do not leak. Accordingly, no crosstalk, signal leak, etc. occur, which enables generation of an excellent display image.
In the embodiment described with reference to
The gate signal output circuit 53a is set to the three-value drive of gate voltages by setting the SEL1 terminal to the “H” logic, and the gate signal output circuit 53b is set to the three-value drive of gate voltages by setting the SEL2 terminal to the “H” logic. The gate signal output circuit 53c is set to the three-value drive of gate voltages by setting a SEL3 terminal to the “H” logic, and the gate signal output circuit 53d is set to the three-value drive of gate voltages by setting a SEL4 terminal to the “H” logic.
For example, when eight gate signal driver circuits are arranged or formed on a single gate driver IC 12, the number of SEL terminals may be three, and a decoder (3-8 decoder) for selecting one of the eight 3-bit gate signal line driver circuits may be configured.
As described above, in the present disclosure, the SEL terminals enable a switch between the two-value drive of gate voltages and the three-value drive of gate voltages independently or indivisually for the gate signal output circuits 53 corresponding respectively to the gate signal lines 17.
In the present disclosure, the gate signal line 17 connected to the transistors for wringing a video signal is driven by a both-side drive (performed by the two gate driver ICs 12 arranged right and left of a display screen 25). The other gate signal lines for which fast slew rate is not required is driven by a one-side drive (performed by one of the gate driver ICs 12 arranged right and left of the display screen 25).
In this embodiment of the present disclosure, the both-side drive means a drive performed by the two gate driver ICs 12 (12a, 12b) arranged right and left of the display screen 25. However, this is a non-limiting example. The both-side drive means any drive performed by the gate driver IC 12a. For example, the both-side drive includes a drive in which two gate driver ICs (12a, 12b) are connected or arranged at one side of a gate signal line 17.
In other words, the both-side drive is a drive method in which the single gate signal line 17a is driven by the plurality of gate driver ICs 12 (12a, 12b). Although descriptions are given assuming that the gate signal line 17a is driven by the gate driver ICs 12 (12a, 12b), this is a non-limiting example. For example, the present disclosure covers a configuration in which gate driver circuits (not illustrated) are formed or arranged directly on a panel board 31 according to a technique using TAOS, or a low or high temperature polysilicon, and the gate driver circuits drive gate signal lines 17.
Accordingly, the present disclosure covers a configuration in which gate driver circuits are connected to both sides of a single gate signal line 17. The present disclosure further covers a configuration in which a gate driver IC 12 is connected to one side of a single gate signal line 17, and a gate driver circuit is connected to the other end. The present disclosure further covers a configuration in which two gate driver circuits are connected to one side of a single gate signal line 17.
The present disclosure is explained mainly taking, as an example, a method for applying a video signal voltage to pixels 16 (a program voltage method). However, this disclosure is a non-limiting example. A method for applying a video signal current to pixels 16 (a program current method) is also possible. A digital drive method, such as a PWM drive, for causing pixels 16 to display the video signal in a flickering or digitally flickering manner. Another drive method is also possible. The drive method may be a luminescence area variation drive in which a luminescence area represents a luminescence intensity.
The PWM drive is, for example, a method in which a voltage of a predetermined value is applied to pixels 16 through switch transistors 11b to turn on or off switch transistors 11d, so that a video is displayed in grayscale according to the number of bits corresponding to the grayscale.
In addition, the switch transistors 11d are controlled to turn on and off to generate a belt-shaped black display (non-display) on the display screen 25 so as to control the amount of current flowing on the display screen 25.
Two gate signal output circuits 53 (53a, 53b) are arranged or formed in the gate driver ICs 12 (12a, 12b). A1, A2, A3, . . . and B1, B2, B3, . . . of the gate signal output circuits 53 denote data units (referred to as blocks 141) whose data is shifted according to a clock of a shift terminal (Clk terminal).
The gate signal output circuit 53a of the gate driver IC 12a drives a gate signal line 17a. The gate signal output circuit 53b of the gate driver IC 12a drives a gate signal line 17b.
In the gate signal output circuit 53a, Blocks A1 and B1 drive (control) pixels 16a, Blocks A2 and B2 drive (control) pixels 16b, and Blocks A3 and B3 drive (control) pixels 16c. The same applies to the succeeding blocks. In other words, in the gate driver IC 12a, an input of a clock (Clk) shifts the pixel row selection position by a pixel row.
In the gate signal output circuit 53b, Block A1 drives (controls) pixels 16a, Block B2 drives (controls) pixels 16b, and Block B2 drives (controls) pixels 16c. The same applies to the succeeding blocks. In other words, in the gate driver IC 12b, an input of a clock shifts the pixel row selection position by two pixel rows.
Accordingly, in order to cause the gate driver IC 12a and the gate driver IC 12b to select a pixel row in synchronization with each other, there is a need to cause the gate driver IC 12b to operate at a clock speed that is the half of the clock speed of the gate driver IC 12a.
The gate driver IC 17a of each pixel row is connected to the gate signal output line 53a of the gate driver IC 12a. In addition, the gate signal line 17a passing through an odd pixel row is connected to the gate signal output circuit 53a of the gate driver 12a, and the gate signal line 17b passing through an even pixel row is connected to the gate signal output circuit 53b of the gate driver 12b. The gate signal line 17b of each pixel row is connected to the gate signal output circuit 53b of the gate driver IC 12a.
With these connections, the gate signal line 17a of each pixel row is subject to a both-side drive by (i) the gate signal output circuit 53a of the gate driver IC 12a and (ii) the gate signal output circuit 53a and the gate signal output circuit 53b of the gate driver IC 12b. Accordingly, it is possible to drive, at a high slew rate, the gate signal line 17a to which the switch transistors 11b for applying a video signal to pixels are connected.
The gate signal line 17b is driven only by the gate signal output circuit 53b of the gate driver IC 12a. However, the switch transistor 11d does not require fast on and off actions. Accordingly, it is possible to realize practically sufficient characteristics by performing the one-side drive only by the gate signal output circuit 53b of the gate driver IC 12a.
The gate driver IC 12a drives the gate signal line 17a and the gate signal line 17b. The gate driver IC 12b drives only the gate signal line 17a. The gate driver IC 12a and the gate driver IC 12b have basically the same configurations. Accordingly, the number of gate driver ICs 12b arranged right of or connected to a display screen 25 may be the half of the number of gate driver ICs 12a arranged left of or connected to the display screen 25. For this reason, compared to a conventional EL display, the number of gate driver ICs 12 (12a, 12b) can be reduced, which enables cost reduction.
For example, in the EL display (EL display panel) illustrated in
The gate driver IC 12a and the gate signal line 17b are ICs having basically the same specifications although they are different in state of connections of control signal lines etc. (as illustrated in
The plurality of gate signal output circuits 53 (53a, 53b) formed or arranged on the gate driver IC 12b drive the gate signal lines 17 (17a, 17b) at different pixel rows. For example, in the configuration in which the two gate signal lines 17 (17a, 17b) are provided per pixel as illustrated in
In
The on data and off data retained or latched in the shift registers 51 (51a, 51b) sequentially shift data retention states in the blocks 141 according to clock signals applied to the clock (Clk) terminals. A shift direction is changed by a logic signal applied to a UD terminal (not illustrated).
Enb terminals are terminals for controlling enable signals. By setting the Enb terminals to Data “H”, an on voltage or an off voltage is output to the gate signal lines 17, in association with the on data or the off data retained or latched in the shift registers 51.
By setting the Enb terminals to Data “L”, an off voltage is output to the gate signal lines 17 or an off voltage in the gate signal lines 17 is retained, irrespective of the on data or the off data retained or latched in the shift registers 51.
In
Although the clock terminal (ClkA) is not illustrated in the gate signal output circuit 53b of the gate driver IC 12a in the drawing of
In
The gate driver IC 12a includes switch circuits 161. The switch circuits 161 are intended to realize the three-value drive of gate voltages in each of
Each of the switch circuits 161 has functions of selecting a voltage from among a voltage Voff1, a voltage Voff2, a voltage Von, and outputting the selected voltage to a corresponding one of the gate signal lines 17.
As illustrated in
The three-value drive of gate voltages illustrated in
As illustrated in
As illustrated in
The voltage Von, the voltage Voff1, the voltage Voff2 are input by external terminals of the gate driver ICs 12 (12a, 12b). In
The plurality of gate driver ICs 12 (12a, 12b) are mounted on a display panel. The voltage Von, voltage Voff1, and voltage Voff2 are applied in common to the plurality of gate driver ICs 12 (12a, 12b).
A voltage Von and a voltage Voff1 appropriate for each of gate signal lines 17 vary depending on a pixel circuit configuration. A requirement level for a Voff2 also varies. Accordingly, it is preferable that the voltage Von, voltage Voff1, and voltage Voff2 can be set independently according to the kind of each gate signal line 17.
For example, taking the pixel circuit in
Normally, a voltage Voff1 appropriate for the gate signal line 17b is higher than those of the other gate signal lines 17 (17a to 17d). This is because the voltage Voff1 to be applied to the switch transistor 11d is made higher than the other so as to reduce an absolute value (Von−Voff1) of a voltage to be applied to the switch transistor 11d.
The switch transistor 11b performs a three-value drive of gate voltages, and the other switch transistors 11d, 11c, and 11e perform a two-value drive of gate voltages. Accordingly, the gate signal line 17b requires a voltage Voff2, but the other gate signals do not require any voltage Voff2. For this reason, as illustrated in
A voltage Voff2 may be shared by the gate signal output circuits 53 (53a, 53b). This is because, in most cases, one of the gate signal lines 17 which requires a voltage Voff2 is identified by one of transistors 11 which applies a video signal.
A configuration in which a voltage Voff1 and a voltage Voff2 are shared by a plurality of signal output circuits 53 and voltages Von are independent is also provided here as an example. In addition, a configuration in which a voltage Von and a voltage Voff2 are shared by a plurality of signal output circuits 53 and a voltage Voff1 is independent is also provided here as another example.
Each of
In each of
In each of
In each of
In each of
Actions etc. of the gate signal output circuit 53b of the gate driver IC 12a are not explained. This is because actions or methods for driving the gate signal output circuit 53b are identical or similar to those of the gate signal output circuit 53a of the gate driver IC 12a. More specifically, this is because the method performed by the gate signal output circuit 53a of the gate driver IC 12a to select the gate signal line 17a or control an on voltage position is identical or similar in actions to the method performed by the gate signal output circuit 53b of the gate driver IC 12a to select the gate signal line 17b or control an on voltage position.
In each of
To facilitate understanding or simplify the drawings, descriptions regarding a latch and a shift of data by the Clk (ClkA, ClkB1, ClkB2) terminal are not provided.
In each of
In each of
In
The DatA2 terminal of the gate driver IC 12a is set to “L” because actions regarding control of the gate signal lines 17b are not explained in order to facilitate understanding. The DatA2 terminal is, of course, set to “H” or “L” and the EnbA2 terminal is set to “H” or “L” since on and off control is performed for the gate signal lines 17b of the gate driver IC 12a in the method for driving the EL display (EL display panel) in the actual disclosure herein.
In
Likewise, in the gate driver IC 12b, the DatB1 terminal is set to “H” and the EnbB1 terminal is set to “H”. Triggered by an input of the ClkB1 terminal, on data (with a circle mark) is input to the block 141 (A1) of the gate signal output circuit 53a of the gate driver IC 12b. Since the EnbB1 terminal of the gate signal output circuit 53a of the gate driver IC 12b is set to “H”, an on voltage is output to the gate signal line 17a passing through the pixel 16a.
With the settings or control states, the gate signal line 17a passing through the pixel 16a is subject to a both-side drive by the gate signal output circuit 53a of the gate driver IC 12a and the gate signal output circuit 53a of the gate driver IC 12b.
The DatB2 terminal is set to “L” and the EnbB2 terminal is set to “L” in the gate driver IC 12b, and thus, triggered by the input of the ClkB2 terminal, off data (without a circle mark) is input to the block (B1) of the blocks 141 of the gate signal output circuit 53b of the gate driver IC 12b. Since the EnbB2 terminal of the gate signal output circuit 53b of the gate driver IC 12b is set to “L”, an off voltage is output to the gate signal line 17a passing through the pixels 16b. In this case, an off voltage is output to the gate signal line 17a of the pixel 16b because off data (without a circle mark) is retained in the block 141 (B1) of the gate signal output circuit 53b of the gate driver IC 12b even when the EnbB2 terminal of the gate signal output circuit 53b of the gate driver IC 12b is set to “H”.
In other words, voltages (an on voltage and an off voltage) to be output to the gate signal line 17a of the gate driver IC 12b can be controlled using data latched or retained in the block 141. In addition, such control can also be performed by logic setting of the EnbB2 terminal. Accordingly, needless to say, any of these methods is possible in the method for driving the EL display (EL display panel) of the present disclosure.
With the actions and control, in
In
Since the EnbA1 terminal of the gate signal output circuit 53a of the gate driver IC 12a is set to “H”, an off voltage is output to the gate signal line 17a passing through the pixels 16a, and an on voltage is output to the gate signal line 17a passing through the pixels 16b. Accordingly, a video signal applied to a source signal line (not illustrated) is applied to the pixels 16b. The video signal firstly applied to the pixels 16a is retained.
Likewise, in the gate driver IC 12b, the DatB2 terminal is set to “H” and the EnbB2 terminal is set to “H”. Triggered by an input of the ClkB2 terminal, on data (with a circle mark) is input to the block 141 (B1) of the gate signal output circuit 53b of the gate driver IC 12b. Since the EnbB2 terminal of the gate signal output circuit 53b of the gate driver IC 12b is set to “H”, an on voltage is output to the gate signal line 17a of the pixels 16b.
With the settings or control states, the gate signal line 17a passing through the pixels 16b is subject to a both-side drive by the gate signal output circuit 53a of the gate driver IC 12a and the gate signal output circuit 53b of the gate driver IC 12b.
In
With the actions and control, in
In
Likewise, in the gate driver IC 12b, the DatB1 terminal is set to “L” and the EnbB1 terminal is set to “H”. Triggered by an input of the ClkB1 terminal, off data (without a circle mark) is input to the block 141 (A1) of the gate signal output circuit 53a of the gate driver IC 12b. The data of the block 141 (A1) of the gate signal output circuit 53a of the gate driver IC 12b is transferred to the block 141 (A2). Since the EnbB1 terminal of the gate signal output circuit 53a of the gate driver IC 12b is set to “H”, an off voltage is output to the gate signal line 17a of the pixel 16a, and an on voltage is output to the gate signal line 17a passing through the pixels 16c.
With the settings or control states, the gate signal line 17a passing through the pixels 16c is subject to a both-side drive by the gate signal output circuit 53a of the gate driver IC 12a and the gate signal output circuit 53a of the gate driver IC 12b.
Since the DatB2 terminal is set to “L” and the EnbB2 terminal is set to “L” in the gate driver IC 12b and there is no input to the ClkB2 terminal, data of the gate signal output circuit 53b of the gate driver IC 12b is not shifted. Accordingly, the data retained in the block 141 (B1) of the gate signal output circuit 53b of the gate driver IC 12b is not transferred to the block 141 (B2). Since the EnbB1 terminal is set to “L”, an off voltage is applied to the gate signal line 17a passing through the pixel 16b.
With the settings or control states, the gate signal line 17a passing through the pixels 16c is subject to a both-side drive by the gate signal output circuit 53a of the gate driver IC 12a and the gate signal output circuit 53a of the gate driver IC 12b.
With the actions and control, in
In
Likewise, in the gate driver IC 12b, the DatB2 terminal is set to “L” and the EnbB2 terminal is set to “H”. Triggered by an input of the ClkB2 terminal, off data (without a circle mark) is input to the block 141 (B1) of the gate signal output circuit 53a of the gate driver IC 12b. The data of the block 141 (B1) of the gate signal output circuit 53a of the gate driver IC 12b is transferred to the block 141 (B2). Since the EnbB1 terminal of the gate signal output circuit 53b of the gate driver IC 12b is set to “H”, an off voltage is output to the gate signal line 17a passing through the pixels 16b, and an on voltage is output to the gate signal line 17a of the pixels 16d.
With the settings or control states, the gate signal line 17a passing through the pixels 16d is subject to a both-side drive by the gate signal output circuit 53a of the gate driver IC 12a and the gate signal output circuit 53b of the gate driver IC 12b.
Since the DatB2 terminal is set to “L” and the EnbB2 terminal is set to “L” in the gate driver IC 12a and there is no input to the ClkB1 terminal, data of the gate signal output circuit 53a of the gate driver IC 12b is not shifted. Accordingly, the data retained in the block 141 (A1) of the gate signal output circuit 53a of the gate driver IC 12b is not transferred to the block 141 (A2). Since the EnbB1 terminal is set to “L”, an off voltage is applied to the gate signal line 17a passing through the pixels 16c.
With the settings or control states, the gate signal line 17a passing through the pixels 16d is subject to a both-side drive by the gate signal output circuit 53a of the gate driver IC 12a and the gate signal output circuit 53b of the gate driver IC 12b.
With the actions and control, in
As described above, the gate signal line 17a passing through the pixel 16c is subject to the both-side drive by means that: the gate driver IC 12a shifting the data positions of the gate signal output circuits 53a and 53b in synchronization with the ClkA terminal; and the gate driver IC 12b controlling the gate signal output circuits 53a and 53b according to different clocks (ClkB1, ClkB2) alternately or independently and controlling the EnbB1 terminal and the EnbB2 terminal alternately or independently.
In this embodiment, the clock ClkB1 of the gate signal output circuit 53a and the clock ClkB2 of the gate signal output circuit 53b of the gate driver IC 12b are caused to act alternately, and the data positions (with and without a circle mark) in the blocks 141 are shifted. However, the present disclosure is not limited thereto.
For example, in each of
When the enable terminal EnbB1 of the gate signal output circuit 53a is set to “H” and the enable terminal EnbB2 of the gate signal output circuit 53b is set to “L” in the state of
As described above, the drive methods of the present disclosure can of course be performed also by, for example, controlling the gate driver IC 12a and the gate driver IC 12b, or controlling the gate signal output circuit 53a and the gate signal output circuit 53b of each of the gate driver ICs 12. These matters apply also to control of the gate signal line 17b. Needless to say, these are also applicable in other embodiments of the present disclosure.
The above embodiment describes a case where a single mark is provided to some of blocks 141 of each of the gate signal output circuits 53 (53a, 53b). However, the present disclosure is not limited thereto. Data (with or without a circle mark) input to each of shift registers 51 (51a, 51b) inside the gate signal output circuits 53 (53a, 53b) is made through the clock terminals (Clk) and the data terminals (Dat). Accordingly, it is only necessary to control or operate the data terminals and the clock terminals in order to input data to shift registers 51 (51a, 51b) etc. Accordingly, consecutive data items with a circle mark can be input to the shift registers 51, and discrete data items with a circle mark can be serially input to the shift registers 51 (51a, 51b).
Each of
This embodiment of the present disclosure is given focusing on an example of consecutive data items with a circle mark, as illustrated for the purpose of facilitating understanding. In reality, not to mention, data items without a circle mark are retained in blocks 141 other than blocks 141 with a circle mark in the shift register 51.
In
On the other hand, by applying an “H” logic to the DatB1 and DatB2 terminals of the gate driver IC 12b and inputting a clock signal to the ClkB1 and ClkB2 terminals once, a circle mark position (on voltage position) is retained in the block 141 (A1) of the gate signal output circuit 53a and the block 141 (B1) of the gate signal output circuit 53b of the gate driver IC 12b. By setting the EnbB1 terminal and the EnbB2 terminal of the gate signal output circuit 53a of the gate driver IC 12b to “H”, an on voltage is applied (output) to each of the gate signal lines 17a each passing through the pixels 16a or the pixels 16b. The EnbA1 terminal of the gate driver IC 12a is set to With the settings or control states, each of the gate signal lines 17a each passing through the pixels 16a or the pixels 16b is subject to a both-side drive by the gate signal output circuit 53a of the gate driver IC 12a and the gate signal output circuits 53a and 53b of the gate driver IC 12b.
With the settings or control states, the gate signal lines 17a each passing through the pixels 16b or the pixels 16c are subject to a both-side drive by the gate signal output circuit 53a of the gate driver IC 12a and the gate signal output circuits 53a and 53b of the gate driver IC 12b. Accordingly, compared to
With the settings or control states, the gate signal lines 17a each passing through the pixels 16c or the pixels 16d are subject to a both-side drive by the gate signal output circuit 53a of the gate driver IC 12a and the gate signal output circuits 53a and 53b of the gate driver IC 12b. Accordingly, compared to
With the settings or control states, the gate signal lines 17a each passing through the pixels 16d or the pixels 16e are subject to a both-side drive by the gate signal output circuit 53a of the gate driver IC 12a and the gate signal output circuits 53a and 53b of the gate driver IC 12b. Accordingly, compared to
As described above, the consecutive circle mark positions are sequentially shifted to the positions of blocks 141 of the shift registers 51. With reference to
Each of
In the above settings and control states, an on voltage is output to the gate signal lines 17b each passing through the pixels 16a, 16b, or 16c. In addition, an on voltage is output to the gate signal line 17a passing through the pixels 16a. Accordingly, the gate signal line 17a passing through the pixels 16a is subject to a both-side drive, and the gate signal lines 17b each passing through the pixels 16a, 16b, or 16c are subject to a one-side drive. In the pixel configuration in
With the above actions or operations, it is possible to turn on or off an arbitrary pixel row of the EL display (EL display panel) by controlling or operating the gate signal output circuit 53b of the gate driver IC 12a. In addition, a duty drive can be performed by switching-on positions. Needless to say, the above embodiments are also applicable to other embodiments in the present disclosure. In addition, the above embodiments can be combined with other embodiments.
In the above settings and control states, an on voltage is output to the gate signal lines 17b each passing through the pixels 16b, 16c, or 16d. In addition, an on voltage is output to the gate signal line 17a passing through the pixels 16b. Accordingly, the gate signal line 17a passing through the pixel 16b is subject to a both-side drive, and the gate signal lines 17b each passing through the pixels 16b, 16c, or 16d are subject to a one-side drive.
As described above, each of the gate signal lines 17a is subject to the both-side drive by the gate signal output circuit 53a of the gate driver IC 12a and the gate signal output circuits 53a and 53b of the gate driver IC 12b. The gate signal output circuit 53b of the gate driver IC 12a performs a one-side drive on the gate signal line 17b.
As described above, the consecutive circle mark positions are sequentially shifted to positions of blocks 141 of the shift registers 51, and a duty drive etc. is performed.
In the present disclosure as described above, the gate driver IC 12a and the gate driver IC 12b have the same gate driver ICs 12 intended to realize or perform either a both-side drive or a one-side drive on each gate signal line 17 by controlling or operating control terminals (such as Dat terminals, Enb terminals, Clk terminals) according to positions (a right position of the display screen 25, a left position of the display screen 25) at which the EL display (EL display panel) is mounted.
Accordingly, by generating gate drivers IC 12 (12a, 12b) of one kind according to the present disclosure and mounting them on EL displays having a wide variety of pixel circuits, the EL displays which realize excellent image display can be provided. The gate driver ICs 12 (12a, 12b) of the present disclosure can be appropriate for such a wide variety of pixel circuits. Accordingly, the gate driver ICs 12 (12a, 12b) can be used as general-purpose ones. Since mass production of these ICs is possible, the cost can be reduced.
In addition, the gate driver ICs 12 (12a, 12b) of the present disclosure can set scanning directions for the shift registers using a vertical inverse setting logic terminal (the UD terminal, for example see
Furthermore, the three-value drive of gate voltages and the two-value drive of gate voltages are realized by performing control or setting on SEL terminals etc. In particular, since an EL display (EL display panel) includes a plurality of gate signal lines 17 passing through pixels 16, the physical positions of the gate signal lines 17 which should be subject to a both-side drive for pixels are not determined until the pixels are laid out (the physical positions are, for example, the positions of the gate signal lines 17a which apply a video signal to corresponding ones of the pixels 16). However, it is unpractical to develop or design gate driver ICs 12 (12a, 12b) etc. after the pixel layout design was completed because it takes significantly long time to complete manufacturing the EL display (EL display panel). In the present disclosure, the gate driver ICs 12 (12a, 12b) can be mounted on any of positions (a right position of the display screen 25, a left position of the display screen 25) in the EL display (the EL display panel). Furthermore, it is possible to easily perform a both-side drive or a one-side drive on each gate signal line 17 by, for example, controlling the gate signal output circuit 53. It is possible to select and perform either the three-value drive of gate voltages or the two-value drive of gate voltages on any of the gate signal lines 17.
In addition, as illustrated in each of
As illustrated in each of
In addition, the pixels according to the present disclosure are similar to the pixels 16 illustrated in
The gate driver ICs 12 (12a, 12b) have identical or similar specifications or configurations. Accordingly, the UDA terminal of the gate driver IC 12a and the UDB terminal of the gate driver IC 12b are provided with opposite logic settings. For example, when the UDA terminal is set to “H”, the UDB terminal is set to “L”.
One (ClkA1 terminal) of clock terminals (Clk terminals) is shared by gate signal output circuits 53a and 53b of each of the gate driver ICs 12 (12a, 12b), and another one (ClkA2 terminal) of the clock terminals (Clk terminals) is shared by gate signal output circuits 53c and 53d of each of the gate drivers IC 12 (12a, 12b). This configuration is intended to cause the gate signal output circuits 53a and 53b to operate at an identical clock and cause the gate signal output circuits 53c and 53d to operate at an identical clock in the gate driver IC 12b, and to apply the wire-connection state of the gate driver IC 12b (the connection state of the Clk terminal) to the gate driver IC 12a.
Since the gate signal output circuits 53a, 53b, 53c, and 53d are operated at an identical clock in the gate driver IC 12a according to the drive method illustrated with reference to
In
In the gate driver IC 12b: a DatB1 terminal and an EnbB1 terminal are connected to the the gate signal output circuit 53a; and a DatB2 terminal and an EnbB2 terminal are connected to the gate signal output circuit 53b. In the gate driver IC 12b: a DatB3 terminal and an EnbB3 terminal are connected to the gate signal output circuit 53c; and a DatB4 terminal and an EnbB4 terminal are connected to the gate signal output circuit 53d.
In
The DatB1 terminal, the DatB2 terminal, the DatB3 terminal, and the DatB4 terminal of the gate driver IC 12b are set to “H”, and triggered by clock inputs of the ClkB1 and ClkB terminals, data with a circle mark is set to the blocks 141 (A1, B1, C1, D1) of the gate driver IC 12a.
Since the EnbB1 terminal and the EnbB2 terminal of the gate driver IC 12b are set to “H”, and the EnbB3 terminal and the EnbB4 terminal are set to “L”, an on voltage is applied to the gate signal lines 17a and 17b of the pixels 16a, and an off voltage is applied to the gate signal lines 17c and 17d passing through the pixels 16a. An off voltage is applied to the gate signal lines 17 passing through the other pixels 16.
With the setting states, the gate signal lines 17a and 17b passing through the pixels 16a are subject to a both-side drive. The gate signal lines 17c and 17d passing through the pixels 16a (the pixel row in which the pixels 16a are positioned) are subject to a one-side drive. As described above, by using the identical gate driver ICs 12 and arranging the gate driver ICs 12a and 12b right and left of a display screen 25, the present disclosure makes it possible to easily perform a both-side drive and a one-side drive. Here, the scanning direction of the gate driver ICs 12a and 12b are inverted.
The gate signal line 17a is connected to switch transistors 11b which apply a video signal. It is possible to turn on or off the switch transistors 11b quickly by performing a both-side drive on the gate signal line 17a. Furthermore, it is possible to turn on or off the switch transistors 11b further quickly by performing a three-value drive of gate voltages on the gate signal output circuit 53a which drives the gate signal lines 17a. Accordingly, it is possible to realize excellent image (video) writing on the display screen 25.
The switch transistors 11d which function or act at the time of offset cancellation are connected to the gate signal line 17b. It is possible to turn on or off the switch transistors 11d quickly by performing a both-side drive on the gate signal line 17b. Furthermore, it is possible to turn on or off the switch transistors 11b further quickly by performing a three-value drive of gate voltages on the gate signal output circuit 53b which drives the gate signal line 17a. Accordingly, an excellent offset cancellation is performed.
Here, the voltage value of an on voltage (Von) to be applied to an input terminal (VonB terminal) for an on voltage of the gate signal output circuit 53b is set to be higher than the voltage values of input terminals (VonA, VonC, VonD) for the other on voltages. For example, the setting is performed such that a voltage VonB>a voltage VonA is satisfied. Preferably, the VonB voltage is set to be from +3 (V) to +15 (V) inclusive with respect to the voltage VonA. Preferably, the voltage VonB is set to be from +5 (V) to +10 (V) inclusive with respect to the voltage VonA. It is possible to reduce the on resistances of the switch transistors 11d by increasing the voltage vonB (the on voltages of the switch transistors 11d). Accordingly, it is possible to reduce a voltage fall between channels of the switch transistors 11d, and to thus reduce an anode voltage Vdd and power consumed by the EL display (EL display panel).
As described above, according to the present disclosure, it is possible to arbitrarily set or apply an on voltage Von of the gate signal output circuit 53. In addition, it is possible to set the drive method of the gate signal output circuit 53 (a two-value drive of gate voltages, a three-value drive of gate voltages, etc.). Accordingly, it is possible to provide excellent image display, and to reduce power to be consumed by the EL display (EL display panel). Needless to say, the above embodiments are also applicable to other embodiments in the present disclosure. In addition, the above embodiments can of course be combined with other embodiments.
The gate signal line 17c and the gate signal line 17d drive switch transistors 11e and 11c. The switch transistors 11e each have a function for applying a reference voltage (voltage Vref) to the gate terminal of a corresponding one of driver transistors 11a. Application of the voltage Vref does not need to be performed quickly. Accordingly, a one-side drive is sufficient for the gate signal line 17c. The switch transistors 11c each have a function for applying an initial voltage (voltage Vini) to a second terminal of the corresponding driver transistor 11a. Application of the voltage Vini does not need to be performed quickly. Accordingly, a one-side drive is sufficient for the gate signal line 17d.
As described above, the gate signal lines 17 (17a, 17b) that require a both-side drive is driven by the gate driver IC 12a and the gate driver IC 12b. The gate signal lines 17 (17c, 17d) that require a one-side drive is driven by the gate driver IC 12a. It is possible to reduce the number of gate driver ICs 12b by performing the drives or arranging the gate driver ICs 12, and to thus reduce the cost of the EL display (EL display panel). As the gate driver IC 12a and the gate driver IC 12b, the gate driver ICs 12 having identical specifications (same kind ones) can be employed. Accordingly, it is possible to increase flexibility of the gate driver ICs 12, and to reduce the cost for developing and designing the gate driver ICs 12.
Data items with a circle mark of the blocks 141 (A1, B1, C1, D1) of the gate driver IC 12a are shifted in the shift registers, and are retained in blocks 141 (A2, B2, C2, D2). In addition, since the EnbA1 terminal, the EnbA2 terminal, the EnbA3 terminal, and the EnbA4 terminal of the gate driver IC 12a are set to “H”, an on voltage is applied to the gate signal lines 17a, 17b, 17c, and 17d passing through the pixels 16b and driven by the gate driver IC 12a. An off voltage is applied to the gate signal lines 17 passing through the other pixels 16 (16a, 16c, . . . ).
The DatB1 terminal, the DatB2 terminal, the DatB3 terminal, and the DatB4 terminal of the gate driver IC 12b are set to “L”, and clock inputs of the ClkB1 and ClkB2 terminals have not been provided from the state of
The EnbB1 terminal and the EnbB2 terminal of the gate driver IC 12b are set to “L”, and the EnbB3 terminal and the EnbB4 terminal of the gate driver IC 12b are set to “H”. Accordingly, an off voltage is applied to the gate signal lines 17a and 17b passing through the pixels 16a, and an on voltage is applied to the gate signal lines 17a and 17b passing through the pixels 16b (the pixel row in which the pixels 16b are positioned). An off voltage is applied to the gate signal lines 17 passing through the other pixels 16.
With the setting states, the gate signal lines 17a and 17b passing through the pixels 16b (the pixel row in which the pixels 16b are positioned) are subject to a both-side drive. The gate signal lines 17c and 17d passing through the pixels 16b (the pixel row in which the pixel 16b is positioned) are subject to a one-side drive.
The DatB1 terminal, the DatB2 terminal, the DatB3 terminal, and the DatB4 terminal of the gate driver IC 12b are set to “L”, and a clock is input to the two ClkB1 and ClkB2 terminals. Accordingly, data items with a circle mark in the blocks 141 (A1, B1, C1, D1) of the gate driver IC 12b are shifted to the blocks 141 (A2, B2, C2, D2) and retained therein.
The EnbB1 terminal and the EnbB2 terminal of the gate driver IC 12b are set to “H”, and the EnbB3 terminal and the EnbB4 terminal of the gate driver IC 12b are set to “L”. Accordingly, an on voltage is applied to the gate signal lines 17a and 17b passing through the pixels 16c (the pixel row in which the pixels 16c are positioned), and an off voltage is applied to the gate signal lines 17a and 17b passing through pixels 16d. An off voltage is applied to the gate signal lines 17 passing through the other pixels 16.
With the setting states, the gate signal lines 17a and 17b passing through the pixels 16c (the pixel row in which the pixels 16c are positioned) are subject to a both-side drive. The gate signal lines 17c and 17d passing through the pixels 16c (the pixel row in which the pixels 16c are positioned) are subject to a one-side drive.
Data items with a circle mark of the blocks 141 (A3, B3, C3, D3) of the gate driver IC 12a are shifted in the shift registers, and are retained in the blocks 141 (A4, B4, C4, D4). In addition, since the EnbA1 terminal, the EnbA2 terminal, the EnbA3 terminal, and the EnbA4 terminal of the gate driver IC 12a are set to “H”, an on voltage is applied to the gate signal lines 17a, 17b, 17c, and 17d passing through the pixels 16d (the pixel row in which the pixels 16d are positioned) and driven by the gate driver IC 12a. An off voltage is applied to the gate signal lines 17 passing through the other pixels 16 (16a, 16b, 16c, 17e . . . ).
The DatB1 terminal, the DatB2 terminal, the DatB3 terminal, and the DatB4 terminal of the gate driver IC 12b are set to “L”, and no clocks have been input to the ClkB1 and ClkB2 terminals have not been provided from the state of
The EnbB1 terminal and the EnbB2 terminal of the gate driver IC 12b are set to “L”, and the EnbB3 terminal and the EnbB4 terminal of the gate driver IC 12b are set to “H”. Accordingly, an on voltage is applied to the gate signal lines 17a and 17b passing through the pixels 16d, and an off voltage is applied to the gate signal lines 17a and 17b passing through the pixels 16c. An off voltage is applied to the gate signal lines 17 passing through the other pixels 16.
With the setting states, the gate signal lines 17a and 17b passing through the pixels 16d (the pixel row in which the pixels 16d are positioned) are subject to a both-side drive. The gate signal lines 17c and 17d passing through the pixels 16d (the pixel row in which the pixels 16d are positioned) are subject to a one-side drive.
In each of
In
Although this embodiment has been described taking a pixel configuration in
As in
In each pixel 16 in
In
A first terminal of the switch transistor 11e is connected to an electrode or a line to which a reset voltage Va is applied, and a second terminal of the switch transistor 11e is connected to the gate terminal of the driver transistor 11a. The gate terminal of the switch transistor 11e is connected to the gate signal line 17c.
A first terminal of the switch transistor 11b which provides the pixel 16 with a video signal is connected to the source line 18, and a second terminal of the switch transistor 11b is connected to a first terminal of a second capacitor 19b. A second terminal of the second capacitor 19b is connected to the gate terminal of the driver transistor 11a. The gate terminal of the switch transistor 11b is connected to the gate signal line 17a.
A first terminal of a first capacitor 19a is connected to an anode voltage Vdd, a second terminal of the first capacitor 19a is connected to the first terminal of the second capacitor 19b of the gate terminal of the driver transistor 11a.
A first terminal of the switch transistor 11c is connected to the gate terminal of the driver transistor 11a, and a second terminal of the switch transistor 11c is connected to a second terminal of the driver transistor 11a. The gate terminal of the switch transistor 11c is connected to the gate signal line 17b.
Multiple gates (at least dual gates) are used for at least one of the switch transistors 11b and 11e in combination with an LDD structure, which makes it possible to reduce off leak and realize excellent contrast and offset cancellation. In addition, an excellent high luminance display and image display can be obtained.
The gate signal line 17a and the gate signal line 17c are driven at both sides by the gate driver IC 12a and the gate driver IC 12b. In addition, the gate signal line 17c and the gate signal line 17d are driven at one side by the gate driver IC 12a.
In
Needless to say, the drive methods according to the present disclosure are applicable also to the pixel configuration in
In
Each of control terminals (Enb, Dat, Clk) are arranged or formed at at least two positions in the gate signal output circuit 53. SEL terminals are arranged between driver output terminals 72 and the Von terminals.
An output from the gate signal output circuit 53 is output from a connection terminal 71 after passing through the driver output terminal 72 of the gate driver IC 12 and a COF line 74. A gate signal line 17 is connected to the connection terminal 71.
Control signals such as Dat1, Dat2, Enb1, Enb2, Clk1, Clk2 etc. are bi-directional signals. Accordingly, data can be transferred in a direction from connection terminals 75a to 75b, and also in a direction of connection terminals 75b to 75a. The data transfer direction is switched by logic control performed by a transfer direction switching terminal (not illustrated).
The gate driver IC 12 includes a switch circuit 161. The switch circuit 161 is a switch circuit for realizing three-value drives of gate voltages in
The three-value drive of gate voltages illustrated in
Needless to say, this embodiment is also applicable to other embodiments in the present disclosure. In addition, this embodiment can of course be combined with other embodiments.
Each of the R, G, and B gamma circuits includes a ladder resistor provided with eight taps (Vi0, Vi1, Vi2, Vi3, Vi4, Vi5, Vi6, and Vi7) each connected to a terminal of the source driver IC (circuit) 14.
The tap position of Vi0 is a minimum grayscale of video signals (a minimum voltage value or an origin). The tap position of Vi7 is a maximum grayscale of video signals (a maximum voltage value).
The tap position of Vi1 corresponds to a voltage value equal to 1/1024 of a video signal amplitude or a voltage value approximate thereto.
The tap position of Vi2 corresponds to a voltage value equal to 1/36 of the video signal amplitude or a voltage value approximate thereto.
The tap position of Vi3 corresponds to a voltage value equal to 1/12 of the video signal amplitude or a voltage value approximate thereto.
The tap position of Vi4 corresponds to a voltage value equal to ⅙ of the video signal amplitude or a voltage value approximate thereto.
The tap position of Vi5 corresponds to a voltage value equal to ⅓ of the video signal amplitude or a voltage value approximate thereto.
The tap position of Vi6 corresponds to a voltage value equal to ⅔ of the video signal amplitude or a voltage value approximate thereto.
A gamma curve can be set or changed as illustrated in
The amplitude of the video signals can be changed by changing or modifying the tap positions (Vi0 to Vi7) at which the voltages are to be input (set). For example, as illustrated in
When the voltages Vi1 and Vi7 are changed, the amplitude of the video signals is also changed. When the amplitude of the video signals is changed, output voltages (on voltages and off voltages) of the gate driver ICs 12 are changed. As described earlier, each gate driver IC 12 of the present disclosure can change or set an on voltage (Von) and off voltages (Voff1, Voff2). Accordingly, for example, a combination with the source driver IC (circuit) 14 in
According to the present disclosure, the switch transistors 11 which apply video signals to the pixels 16 perform a both-side drive.
In addition, the switch transistors 11 which act or contribute at the time of offset cancellation perform a both-side drive. On the other hand, an one-side drive is sufficient for some of the switch transistors (e.g. switch transistors 11d) which do not affect image display even if an on or off delay occurred.
As described above, according to the present disclosure, one of a both-side drive or a one-side drive is selected based on on or off time required for the transistors 11 of the pixels 16 or based on a load capacity of each gate signal line 17. Here, a three-value drive of gate voltages or a two-value drive of gate voltages is selected.
As described above, relationships between the video for image display and (i) rise or fall times of gate signal lines or (ii) on or off times of the transistors 11 are important. In other words, it is important that relationships between video signal systems and control systems of the switch transistors 11 are set or adjusted to the optimum ones.
For this reason, according to the present disclosure, a delay circuit 485 is formed or provided in the source driver IC 14 as illustrated in
In
Ten combinations of comparator input signals LV0A, LV0B to LV9A, LV9B are output to a digital receiver 481. A video signal from the digital receiver 481 is latched in a latch circuit 484, and retained in a period of 1 H (one horizontal scanning period) or 2 H (two horizontal scanning periods).
A video signal from the latch circuit 484 is input to the delay circuit 485, and the delay circuit 485 delays the video signal according to a preset action or a control method.
An output of the delay circuit 485 is applied to a digital-analog (DA) conversion circuit 486. The DA conversion circuit 486 outputs an analog voltage on which gamma conversion was performed, according to voltages VXi0 to VXi7 (X: R, G, or B) set in gamma setting circuits 482.
An output from the DA conversion circuit 486 is input to a buffer circuit 487, and is output to the source signal lines Y1 to Y720 via a switch circuit 488. The buffer circuit 487 is configured to have settings of a plurality of buffer performances such as Strong, Middle, and Weak.
The switch circuit 488 is a switch circuit capable of selecting one of a precharge voltage or a video signal voltage. When a precharge voltage is selected, the precharge voltage is applied to a corresponding one of the source signal lines Y1 to Y720, and electric charge accumulated in the corresponding one of the source signal lines Y1 to Y720 is forcibly charged or released.
It is preferable that gamma characteristics be set to be linear as illustrated in
Voltage settings to the terminals for the voltages VXi0 to VXi7 (X denotes R, G, or B) can be performed from outside the source driver IC (circuit) 14. A gamma curve can be arbitrarily set by setting voltages.
Needless to say, this embodiment is also applicable to other embodiments in the present disclosure. In addition, this embodiment can of course be combined with other embodiments.
The present disclosure has been explained taking EL display panels as examples in this specification, but the technical ideas of the present disclosure are not limited to the EL display panels. For example, the matters relating to the methods for the COFs in the present disclosure are of course applicable to LCDs etc.
Details (or part of the details) in the above embodiment described with reference to the drawings are applicable to various kinds of electronic devices. More specifically, the details are applicable to display parts of such electronic devices.
Examples of such electronic devices include: video cameras; digital cameras; goggles type displays; navigation systems; audio reproduction devices (car audio devices, audio compositions, etc.); computers; gaming machines; mobile information terminals (mobile computers, mobile telephones, mobile gaming machines, or electronic book readers, etc.); image reproduction devices with recording media (specifically, devices capable of reproducing images recorded on the recording media such as digital versatile discs (DVDs) and having a display on which the images can be displayed).
This applies to other drawings. The matters and content illustrated in the drawings or described in this embodiment of the specification according to the present disclosure are also applicable to other embodiments. The EL display panel illustrated in the drawings or described in this embodiment disclosed herein is applicable to EL displays according to the present disclosure.
For example, needless to say, as an EL display 491 of a note type personal computer in
In the specification and drawings, generic names may be used to refer to the identical, similar, or related ones. For example, when both gate signal lines 17 and source signal lines 18 are described at the same time, these lines may be described or illustrated as signal lines 17 (18). A glass substrate 48 and a sealing substrate 30 may be referred to as substrates 30 (48).
Parts assigned with the same numbers or symbols have identical or similar shapes, materials, functions, relevant matters, perform identical or similar actions, or provide identical or similar effects.
In the embodiments of the specification and the drawings, matters, structures, effects etc. as described in other embodiments of the specification and the drawings are applicable unless otherwise specified, and thus the identical or similar descriptions etc. are not repeated.
The details illustrated in the drawings etc. can be combined with other embodiments etc. even when no such indication is provided. For example, it is possible to configure an information display device as illustrated in
In this disclosure, for convenience′ sake, configurations with only a panel are normally referred to as EL display panels, and configurations including a peripheral circuit such as a COF 22g as illustrated in
Although the COF 22g or the gate driver ICs 12 have been described in each of the embodiments of the present disclosure, the technical idea of the present disclosure is of course also applicable to the COF 22s or the source driver IC 14 in the embodiment.
Accordingly, the matters described in the specification are of course applicable to the COF 22s or the source driver IC 14, and also to the EL display including the same. This embodiment is of course also applicable to other embodiments in the present disclosure. In addition, this embodiment can be of course combined with other embodiments.
Although the driver transistors 11a and the switch transistors 11 (11b, 11c, 11d, 11e) have been described as thin-film transistors in the present disclosure, the present disclosure is not limited to the thin-film transistors. Thin-film diodes (TFD) or the like can be used to configure the same.
Such thin-film elements are non-limiting examples, and transistors formed on a silicon wafer are also possible. For example, transistors may be firstly formed on a silicon wafer, then pealed off from the silicon wafer, and finally printed on a glass board.
As a matter of course, the transistors 11 may be FETs, MOS-FETs, MOS transistors, or bi-polar transistors.
It is preferable that the transistors 11 according to the present disclosure be configured to have a lightly doped drain (LDD), irrespective of whether each transistor 11 is an N-channel transistor or a P-channel transistor.
Each transistor 11 may be made any of a high temperature polysilicon (HTPS), a low temperature polysilicon (LTPS), a continuous grain silicon (CGS), a transparent amorphous oxide semiconductor (TAOS, IZO), an amorphous silicon (AS), or an infrared RTA.
In
Preferably, the transistors have a top gate structure. With the top gate structure, parasitic capacitance is reduced. This is because a gate electrode pattern of the top gate serves as a light blocking layer which blocks light emitted from EL elements 15, to reduce operation errors by the transistors and off-leak currents.
It is preferable to perform a process for enabling employment of copper lines or copper alloy lines as line materials for either gate signal lines or source signal lines, or both of gate signal lines and source signal lines. This is because line resistances of the signal lines can be reduced, which makes it possible to realize a larger EL display panel.
It is preferable that gate signal lines 17 driven (controlled) by a gate driver IC (circuit) 12 be configured to have a low impedance. Accordingly, the same applies to the configuration or structure of gate signal lines 17.
In particular, it is preferable that a low temperature polysilicon be employed. With the low temperature polysilicon, transistors are configured to have a top gate structure and thus have a small parasitic capacitance, P-channel transistors can be generated, and a copper wiring or copper alloy wiring process can be used. Preferably, a Tu-Cu-Ti three layer structure be employed for the copper lines.
In the case of a transparent amorphous oxide (TAOS) semiconductor, an Mo-Cu-Mo three layer structure be employed.
The thickness, size, etc. of some part are magnified or reduced to simplify explanation. This applies to the other drawings.
The panel board 31 described as a glass substrate may be a panel board 31 formed using a silicon wafer. Alternatively, the panel board 31 may be a panel board 31 formed using a metal substrate, a ceramic substrate, a plastic sheet (plate), or the like.
The materials and configurations for a sealing substrate 30 are similar to those for the panel board 31. In order to provide excellent heat dissipation, each of the sealing substrate 30 and the panel board 31 may of course be a sealing substrate 30 and a panel board 31 made of sapphire glass, or the like.
Needless to say, the embodiment is also applicable to other embodiments in the present disclosure. In addition, this embodiment can be of course combined with other embodiments.
By configuring the information devices or the like in
The embodiments can be performed in arbitrary combination with other embodiments.
The present disclosure makes it possible to reduce the number of control lines which are formed in serial connection on COFs can be reduced, and to provide EL displays with an excellent yield at low cost.
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| Filing Document | Filing Date | Country | Kind |
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| PCT/JP2013/006030 | 10/9/2013 | WO | 00 |
| Publishing Document | Publishing Date | Country | Kind |
|---|---|---|---|
| WO2014/061235 | 4/24/2014 | WO | A |
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