The present invention relates to a display device.
In regard to a display device, PTLs 1 to 3 disclose a configuration in which a dummy region not being used for display is provided around a display region. Further, in recent years, a display device in which a display region is formed on a surface and a side surface has been put to practical use.
In the display device as described above, a fine metal mask (FMM) is used when a luminescent material is deposited during manufacturing. In a case of the display device in which a display region is formed on a surface and a side surface, display in the side display region is required, but it is particularly difficult to maintain a mask precision at an end portion of the display region. Thus, there is a problem in that a yield becomes poor and a cost increases.
The present invention has been made to solve the above-described problem, and an object thereof is to improve a yield of a display device in which a display region is formed on a surface and a side surface.
In order to solve the above-described problem, a display device according to an aspect of the present invention in which a plurality of light-emitting elements are formed, the plurality of light-emitting elements each including a first electrode, an edge cover formed in a layer above the first electrode and covering an end portion of the first electrode, a light-emitting layer formed in a layer above the first electrode, and a second electrode formed in a layer above the light-emitting layer is the display device including: a first display region provided on a surface of the display device, a plurality of first light-emitting elements being formed in the first display region; and a second display region continuous with the first display region and provided on a side surface of the display device, a plurality of second light-emitting elements being formed in the second display region, wherein a first opening of the edge cover that exposes the first electrode of the first light-emitting element is larger than a second opening of the edge cover that exposes the first electrode of the second light-emitting element, and a first light-emitting layer that overlaps the first opening and is the light-emitting layer has equal shape and equal size to a second light-emitting layer that overlaps the second opening and is the light-emitting layer.
According to an aspect of the present invention, a yield of a display device in which a display region is formed on a surface and a side surface can be improved.
(a) of
The display panel P includes a surface display region DA (first display region) disposed on a surface (front) side of the display device 1, and a side display region DB (second display region) continuous with the surface display region DA and disposed on a side surface side of the display device 1. In the display device 1 according to the present embodiment, the side display region DB is formed on each of two side surfaces extending in a longitudinal direction of the display device 1. However, the side display region DB may be formed on at least one of the two side surfaces extending in the longitudinal direction of the display device 1.
Note that, in the surface display region DA of the display panel P, a notch portion L is formed in one side extending in a short-hand direction. However, the notch portion L is not necessary and may be omitted.
The side display region DB includes a first side display region DB1 and a second side display region DB2. The first side display region DB1 is formed along an end portion (both left and right end portions of the display panel P) of the side display region DB on an opposite side to the surface display region DA. The second side display region DB2 is formed so as to be sandwiched between the surface display region DA and the first side display region DB1. In other words, the second side display region DB2 is formed along an end portion of the side display region DB on the surface display region DA side.
The display panel P includes a group of subpixels SPA (first light-emitting elements) formed in the surface display region DA, a group of subpixels SPB (second light-emitting elements) formed in the first side display region DB1, and a group of subpixels SPC (third light-emitting elements) formed in the second side display region DB2. The display panel 1 displays information in the surface display region DA and the side display region DB.
Note that a shape of the display panel P is not particularly limited as long as the display panel P includes the surface display region DA and the side display region DB. For example, four corners of the display panel P may be formed at a substantially right angle or may be formed in a curved shape.
Examples of the material of the resin layer 12 include polyimide, epoxy, and polyamide. Examples of the material of the base material 10 include polyethylene terephthalate (PET).
The barrier layer 3 is a layer that inhibits moisture or impurities from reaching the TFT layer 4 or the light-emitting element layer 5 when the display device 1 is being used, and can be constituted by a silicon oxide film, a silicon nitride film, or a silicon oxynitride film, or by a layered film of these, for example, formed using chemical vapor deposition (CVD).
The TFT layer 4 includes a semiconductor film 15, an inorganic insulating film 16 formed in a layer above the semiconductor film 15, a gate electrode G formed in a layer above the inorganic insulating film 16, an inorganic insulating film 18 formed in a layer above the gate electrode G, a capacitance electrode C formed in a layer above the inorganic insulating film 18, an inorganic insulating film 20 formed in a layer above the capacitance electrode C, a source electrode S and a drain electrode D both formed in a layer above the inorganic insulating film 20, and a flattening film 21 formed in a layer above the source electrode S and the drain electrode D.
A thin film transistor Tr is configured to include the semiconductor film 15, the inorganic insulating film 16 (the gate insulating film), and the gate electrode G. The source electrode S is connected to a source region of the semiconductor film 15, and the drain electrode D is connected to a drain region of the semiconductor film 15.
The semiconductor film 15 is formed of low-temperature polysilicon (LTPS) or an oxide semiconductor, for example. Note that in
Each of the inorganic insulating films 16, 18, and 20 can be formed of, for example, a silicon oxide (SiOx) film or a silicon nitride (SiNx) film, or a layered film of these, formed by using a CVD method. The flattening film (interlayer insulating film) 21 can be formed of, for example, a coatable photosensitive organic material such as a polyimide or an acrylic.
The gate electrode G, the source electrode S, the drain electrode D. and the terminals are formed of a metal single layer film or a layered film including, for example, at least one of aluminum (Al), tungsten (W), molybdenum (Mo), tantalum (Ta), chromium (Cr), titanium (Ti), and copper (Cu).
The light-emitting element layer 5 (e.g., an organic light-emitting diode layer) includes an anode electrode 22 (a first electrode) formed in a layer above the flattening film 21, an edge cover 23 that defines the subpixels SPA, SPB, or SPC in an active area (a region overlapping the light-emitting element layer 5), a light-emitting layer 24 formed in a layer above the anode electrode 22, and a cathode electrode 25 (a second electrode) formed in a layer above the light-emitting layer 24. A light-emitting element (e.g., an organic light-emitting diode, or OLED) is configured to include the anode electrode 22, the light-emitting layer 24, and the cathode electrode 25. In the display device 1, the anode electrode 22 and the cathode electrode 25 can have the opposite arrangement. In other words, the first electrode may be the cathode electrode, and the second electrode may be the anode electrode.
The edge cover 23 surrounds an end portion of the anode electrode 22. The light-emitting layer 24 is formed so as to cover a region (a light-emitting region) surrounded by the edge cover 23 by using vapor deposition or an ink-jet method. When the light-emitting element layer 5 is an organic light-emitting diode (OLED) layer, for example, a hole injection layer, a hole transport layer, the light-emitting layer 24, an electron transport layer, and an electron injection layer are layered above the bottom face of the edge cover 23 (a portion from which the anode electrode 22 is exposed). Here, the layers aside from the light-emitting layer 24 can be common layers.
The anode electrode 22 is formed by layering Indium Tin Oxide (ITO) and an alloy containing Ag, for example, and has light reflectivity (to be described below in more detail). The cathode electrode 25 can be formed of a transparent conductive material such as ITO or Indium Zinc Oxide (IZO).
If the light-emitting element layer 5 is an OLED layer, positive holes and electrons recombine inside the light-emitting layer 24 in response to a drive current between the anode electrode 22 and the cathode electrode 25, and light is emitted as a result of excitons, which are generated by the recombination, falling into a ground state. Since the cathode electrode 25 is transparent and the anode electrode 22 is photoreflective, the light emitted from the light-emitting layer 24 travels upwards and results in top emission.
The light-emitting element layer 5 is not only limited to being configured by the OLED elements, but may also be configured by inorganic light emitting diodes or quantum dot light emitting diodes.
The sealing layer 6 is transparent, and includes an inorganic sealing film 26 that covers the cathode electrode 25, the organic sealing film 27 formed in a layer above the inorganic sealing film 26, and an inorganic sealing film 28 that covers the organic sealing film 27. The inorganic sealing films 26 and 28 may be made of a silicon oxide film, a silicon nitride film, a silicon oxynitride film, or a layered film of these, formed by CVD using a mask, for example. The organic sealing film 27 is thicker than the inorganic sealing films 26 and 28, is a transparent organic film, and can be constituted with a coatable photosensitive organic material such as a polyimide or an acrylic. For example, after coating the inorganic sealing film 26 with an ink containing such an organic material using an ink-jet method, the ink is cured by UV irradiation. The sealing layer 6 covers the light-emitting element layer 5 and inhibits foreign matters, such as water and oxygen, from infiltrating to the light-emitting element layer 5.
The function film 39 has an optical compensation function, a touch sensor function, a protection function, or the like, for example.
As illustrated in (b) of
As illustrated in (c) of
The “equal shape and equal size” mentioned above means that if the luminescent material of the light-emitting layer 24 is deposited in each of the surface display region DA and the side display region DB by using masks having mask patterns of equal shape and equal size, the light-emitting layers 24 of equal shape and equal size will effectively be formed in the surface display region DA and the side display region DB. Accordingly, the light-emitting layer 24 in the subpixel SPA, the light-emitting layer 24 in the subpixel SPB, and the light-emitting layer 24 in the subpixel SPC do not necessarily have to have exactly equal shape and equal size.
As illustrated in
(a) to (c) of
In this way, by making the opening HB smaller than the opening HA and the opening HC, even in a case where there is a lower mask precision in the deposition pattern used when depositing the luminescent material in the first side display region DB1, the subpixel SPB can function correctly. Specifically, when a fine metal mask is stretched while aligning with the mask opening, the fine metal mask can be stretched even in a case where a precision of the mask opening in the end portion of the fine metal mask where it is difficult to have a precision is lowered. Further, even after the fine metal mask is deposited in a mask frame, a twist is easily generated in the mask opening at the end of the fine metal mask due to a relationship in density of the mask opening of the fine metal mask. Even when the twist is generated in such a manner, the subpixel SPB can function correctly according to the present configuration. Thus, a yield of the display device 1 can be improved.
Note that, since the opening HB in the edge cover 23 formed in the second side display region DB2 is smaller than the opening HA in the edge cover 23 formed in surface the display region DA and the opening HC of the edge cover 23 formed in the second side display region DB2, the second side display region DB2 has a poorer display accuracy than the surface display region DA and the second side display region DB2. In other words, the surface display region DA and the second side display region DB2 are suited to the display of high-resolution images, whereas the first side display region DB1 is suited to the display of low-resolution images. However, the side display region DB is not located in front of the user's line of sight, and is provided mainly for icon display for starting up an application. Thus, the display quality may be changed between the surface display region DA and the side display region DB (particularly, the first side display region DB1 located at both end portions of the display panel P).
Note that the first side display region DB1 may be formed along at least the end portion (both left and right end portions of the display panel P) of the side display region DB on an opposite side to the surface display region DA. Even in this case, the yield of the display device 1 described above can be improved. However, the second side display region DB2 may be omitted, and the subpixel SPB may be formed across the entire side display region DB. In this way, the yield of the display device 1 described above can be further improved.
Note that, in order to ensure sufficient light emission from the light-emitting layer 24, a contact hole cannot be provided in the surface display region DA and the second side display region DB2 so as to overlap a part of the light-emitting layer 24 that fills the openings HA and HC. Thus, as illustrated in (a) and (c) of
On the other hand, in the first side display region DB1, a part of the light-emitting layer 24 that does not overlap the opening HB does not function as the effective light-emitting layer 24. Thus, as illustrated in (b) of
Note that a pixel circuit is provided in a matrix corresponding to points in the surface display region DA and the side display region DB where the plurality of data signal lines and the plurality of scanning signal lines intersect.
The pixel circuit illustrated in
The transistors T1 to T7 are p-channel transistors. The capacitor C1 is a capacitance element constituted by two electrodes. A light emission control line is connected to control terminals of T3 and T4. The scanning signal line (n) is connected to control terminals of T2 and T5. The scanning signal line (n−1) is connected to control terminals of T6 and T7. However, the control terminal of T7 may be connected to the scanning signal line (n). An initialization power source line is connected to one of conduction terminals of T6 and T7. The data signal line is connected to one of conduction terminals of T2. A high power supply voltage line is connected to one of conduction terminals of T3. A cathode of the organic EL element is common in the plurality of pixel circuits and electrically connected to a low power supply voltage ELVSS.
The terminal portion 54 is formed in the frame region DC on a side of the other side on an opposite side to one side extending in the short-hand direction in which the notch portion L is formed. The terminal portion 54 is connected to the surface display region DA and the side display region DB via the bent portion 56. In such a display panel P, a display control circuit (not illustrated) such as a monolithic gate driver is formed in the first side display region DB or the frame region DC adjacent to the first side display region DB1, and the terminal portion 54 is formed in the frame region DC.
The display control circuit controls display in the surface display region DA and the side display region DB. The terminal portion 54 is attached to one end of a cable for electrically connecting the display panel P to an external device.
Another embodiment of the present invention will be described below. Note that, for convenience of description, members having the same functions as those of the members described in the above-described embodiment will be denoted by the same reference numerals and signs, and the description thereof will not be repeated.
(a) of
The display panel P includes a surface display region DA (first display region) disposed on a surface (front) side of the display device 11, and a side display region DB (second display region) continuous with the surface display region DA and disposed on a side surface side of the display device 11. In the display device 11 according to the present embodiment, the side display region DB is formed on each of two side surfaces extending in a short-hand direction of the display device 11. However, the side display region DB may be formed on at least one of the two side surfaces extending in the short-hand direction of the display device 11.
In the surface display region DA, a notch portion L is formed in one end portion extending in the short-hand direction. However, the notch portion L is not necessary and may be omitted.
The side display region DB includes a first side display region DB1 and a second side display region DB2. The first side display region DB1 is formed along an end portion (both left and right end portions of the display panel P) of the side display region DB on an opposite side to the surface display region DA. The second side display region DB2 is formed so as to be sandwiched between the surface display region DA and the first side display region DB1. In other words, the second side display region DB2 is formed along an end portion of the side display region DB on the surface display region DA side.
The side display region DB includes a first side display region DB1 and a second side display region DB2. The first side display region DB1 is formed along an end portion (both upper and lower end portions of the display panel P) of the side display region DB on an opposite side to the surface display region DA. The second side display region DB2 is formed so as to be sandwiched between the surface display region DA and the first side display region DB1. In other words, the second side display region DB2 is formed along an end portion of the side display region DB on the surface display region DA side.
The display panel P includes a group of subpixels SPA (first light-emitting elements) formed in the surface display region DA, a group of subpixels SPB (second light-emitting elements) formed in the first side display region DB1, and a group of subpixels SPC (third light-emitting elements) formed in the second side display region DB2. The display panel 1 displays information in the surface display region DA and the side display region DB.
In this way, a position in which the side display region DB is formed is not particularly limited as long as the position is on a side surface of the display device. In other words, the side display region DB may be formed on at least one side surface of the two side surfaces extending in a longitudinal direction of the display device. Further, the side display region DB may be formed on at least one side surface of the two side surfaces extending in the short-hand direction of the display device. Furthermore, the side display region DB may be formed on both of the side surface extending in the longitudinal direction and the side surface extending in the short-hand direction of the display device.
Another embodiment of the present invention will be described below. Note that, for convenience of description, members having the same functions as those of the members described in the above-described embodiment will be denoted by the same reference numerals and signs, and the description thereof will not be repeated.
In
In the present embodiment, in the first side display region DB1, the plurality of subpixels SPB that display the same color can be arranged side-by-side in the column direction. In this case, the plurality of subpixels SPB arranged side-by-side in the column direction are driven by a common image signal. Furthermore, the plurality of subpixels SPB arranged side-by-side in the column direction are electrically connected to a common single anode electrode 22.
As illustrated in
In
In the first side display region DB1, only a single line is necessary to connect the two subpixels SPB arranged in each position (Rn,Cn) to the corresponding light emission control transistor Td. In other words, a wiring line for connecting one of the two subpixels SPB to the corresponding other light emission control transistor Td does not need to be provided in the first side display region DB1. Accordingly, the number of necessary wiring lines in the first side display region DB1 can be reduced, which can make it easier to design the subpixel structure in the first side display region DB1. Furthermore, wiring lines that connect different anode electrodes 22 to each other are not needed in the first side display region DB1, which makes it possible to freely lay out the regions in layers below the anode electrodes 22 in the first side display region DB1. In this way, a monolithic gate driver or the like, for example, can be formed in the first side display region DB1.
In the first side display region DB1, the plurality of the subpixels SPB in the group of the subpixels SPB, which are arranged in different positions, are electrically connected to a common light emission control transistor Td among the plurality of light emission control transistors TdR, TdG, and TdB. For example, the two subpixels SPB arranged in the position (R1,C1) and the two subpixels SPB arranged in the position (R4,C1) three places to the right are electrically connected to the drain electrode of a common light emission control transistor TdR. In other words, four red subpixels SPB are electrically connected to a single light emission control transistor TdR.
In
Based on this, of all the light emission control transistors Td formed in the first side display region DB1, one quarter of those transistors are connected to any one of the subpixels SPB. The remaining three quarters do not need to be connected to subpixels SPB. As such, the locations in the first side display region DB1 where these remaining subpixels SPB are formed can be, for example, incorporated into the gate drivers or used as part of TFTs used for time-division switched driving.
In all of the configurations illustrated in
Note that an electro-optical element (an electro-optical element of which luminance and transmittance are controlled by an electric current) included in the display device according to the first to third embodiments is not particularly limited. Examples of the display device according to the present embodiment include an organic Electro Luminescence (EL) display provided with an Organic Light Emitting Diode (OLED) as the electro-optical element, an inorganic EL display provided with an inorganic light emitting diode as the electro-optical element, and a Quantum dot Light Emitting Diode (QLED) display provided with a QLED as the electro-optical element.
Aspect 1: a display device in which a plurality of light-emitting elements are formed, the plurality of light-emitting elements each including a first electrode, an edge cover formed in a layer above the first electrode and covering an end portion of the first electrode, a light-emitting layer formed in a layer above the first electrode, and a second electrode formed in a layer above the light-emitting layer, the display device including: a first display region provided on a surface of the display device, a plurality of first light-emitting elements being formed in the first display region; and a second display region continuous with the first display region and provided on a side surface of the display device, a plurality of second light-emitting elements being formed in the second display region, wherein a first opening of the edge cover that exposes the first electrode of each of the plurality of first light-emitting elements is larger than a second opening of the edge cover that exposes the first electrode of each of the plurality of second light-emitting elements, and a first light-emitting layer that overlaps the first opening and is the light-emitting layer has equal shape and equal size to a second light-emitting layer that overlaps the second opening and is the light-emitting layer.
Aspect 2: the display device according to aspect 1, wherein the plurality of second light-emitting elements are formed along at least an end portion of the second display region on an opposite side to the first display region.
Aspect 3: the display device according to aspect 2, wherein, in the second display region, a third light-emitting element is formed between the plurality of first light-emitting elements and the plurality of second light-emitting elements, and the first opening has equal shape and equal size to a third opening of the edge cover that exposes the first electrode of the third light-emitting element, and the first light-emitting layer has equal shape and equal size to a third light-emitting layer that overlaps the third opening and is the light-emitting layer.
Aspect 4: the display device according to aspects 1 to 3, wherein the second display region is formed on a side surface extending in a longitudinal direction of the display device.
Aspect 5: the display device according to aspects 1 to 4, wherein the second display region is formed on a side surface extending in a short-hand direction of the display device.
Aspect 6: the display device according to aspects 1 to 5, wherein the first electrode of each of the plurality of second light-emitting elements is smaller than the first electrode of each of the plurality of first light-emitting elements.
Aspect 7: the display device according to aspects 1 to 6, wherein the first electrodes of the plurality of second light-emitting elements configured to emit light of the same color are electrically connected to each other via a wiring line of a TFT layer.
Aspect 8: the display device according to aspects 1 to 6, wherein a common first electrode is formed in the plurality of second light-emitting elements configured to emit light of the same color.
Aspect 9: the display device according to aspects 1 to 8, wherein the plurality of second light-emitting elements configured to emit light of the same color are driven by a common image signal.
Aspect 10: the display device according to aspects 1 to 8, wherein the plurality of second light-emitting elements configured to emit light of the same color are connected to a common drive transistor.
The present invention is not limited to each of the embodiments described above, and various modifications may be implemented within a range not departing from the scope of the claims. Embodiments obtained by appropriately combining technical approaches stated in each of the different embodiments also fall within the scope of the technology of the present invention. Novel technical features may also be formed by combining the technical approaches stated in each of the embodiments.
Filing Document | Filing Date | Country | Kind |
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PCT/JP2018/035802 | 9/26/2018 | WO | 00 |