Patent Application
20100118005
The present invention relates to a plasma display panel and a plasma display device.
A plasma display panel (PDP) has two glass plates adhered to each other and displays an image by emitting discharge light in a space formed between the glass plates. Cells corresponding to pixels in an image are self-luminescence ones, which are coated with phosphors which emit visible lights of red, green, and blue under ultraviolet rays generated by discharge.
For example, a PDP having a 3-electrode structure displays an image by generating sustain discharge between an X-electrode and a Y-electrode. A cell (cell to be lit) to generate the sustain discharge is selected, for example, by selectively generating address discharge between the Y-electrode and an address electrode.
In a general PDP, the X-electrode and the Y-electrode are disposed on a front glass plate, and address electrodes are disposed on a back glass plate. Furthermore, in recent years, a PDP in which three kinds of electrodes of the X-electrode, the Y-electrode, and the address electrodes are disposed on a front glass plate has been proposed (see Patent Document 1, for example). In this PDP, first-layer electrodes such as the X-electrode and the Y-electrode are formed on a glass base, and second-layer electrodes such as address electrodes which are orthogonal to an extension direction of the first-layer electrodes are formed on a dielectric layer covering the first-layer electrodes. The front glass plate includes the glass base and the dielectric layer formed on the glass base.
In the PDP of Patent Document 1, the edge part of the dielectric layer is positioned more inside than the edge part of the glass base and is formed to be inclined. An incline is formed on the edge part of the dielectric layer, so that the connection parts of the second-layer electrodes (address electrodes) are formed on a surface of the glass base. In general, when the dielectric layer is formed by a vapor deposition method or the like, it is difficult to accurately form an incline of the dielectric layer and the manufacturing cost increases. Furthermore, metal microspheres deposit on surfaces of the dielectric layer and the like by a sputtering method or a vapor deposition method, so that the thickness of a metal film formed with metal microspheres is likely to vary on the incline (especially folded portion) of the dielectric layer. For this reason, wirings (metal films) of electrodes may be broken in portions where the metal film is thin. In addition, when an electrode pattern is formed using an exposure process after metal microspheres have deposited on surfaces of the dielectric layer and the like by a sputtering method or a vapor deposition method, it is difficult to obtain accurate focus of exposure on the incline of the dielectric layer and the manufacturing cost increases.
A proposition of the present invention is to easily form connection parts coupled with a circuit driving a PDP in which electrodes orthogonal to each other are formed on a front glass plate.
A plasma display panel has a first and a second plate facing each other. A plurality of first electrodes extending in a first direction and disposed at intervals and a first dielectric layer covering the first electrodes are provided on the first plate. Further, a plurality of second electrodes extending in a second direction orthogonal to the first direction and disposed at intervals are provided on the first dielectric layer. Each of the second electrodes has a connection part to couple with a circuit applying a voltage to the second electrodes at least at one end part of each of the second electrodes, the connection part being provided on the dielectric layer. For example, an edge part on a side of the connection part of the second plate is positioned more inside than the connection part.
According to the present invention, connection parts coupled with a circuit driving a PDP in which electrodes orthogonal to each other are formed on a front glass plate can be easily formed.
Embodiments of the present invention will be described below using the drawings.
The PDP 10 has a front plate part 12 constituting an image display surface 16 and a back plate part 14 facing the front plate part 12. Discharge spaces (cells) not shown in the figure are formed between the front plate part 12 and the back plate part 14. The front plate part 12 and the back plate part 14 are made of, for example, glass plates. An optical filter 20 is adhered to a protection glass (not shown) which is attached to an opening part 32 of the front case 30. The optical filter 20 may have an electromagnetic wave shielding function. Furthermore, the optical filter 20 may be directly adhered not to the protection glass but to the image display surface 16 side of the PDP 10.
The front plate part 12 has X bus electrodes Xb and Y bus electrodes Yb which are formed in parallel along the first direction D1 and formed alternately along the second direction D2 on a glass base FS (first plate) (on the underside of it in the figure) in order to generate discharge (sustain discharge) repeatedly. An X transparent electrode Xt extending in the second direction D2 from the X bus electrode Xb toward the Y bus electrode Yb is coupled with the X bus electrode Xb. Furthermore, a Y transparent electrode Yt extending in the second direction D2 from the Y bus electrode Yb toward the X bus electrode Xb is coupled with the Y bus electrode Yb. In other words, the X transparent electrode Xt and the Y transparent electrode Yt face each other along the second direction D2.
The X bus electrodes Xb and the Y bus electrodes Yb are opaque electrodes made of metal material or the like, and the X transparent electrodes Xt and the Y transparent electrodes Yt are transparent electrodes which are made of ITO film or the like and transmit light. The transparent electrodes Xt and Yt may be disposed in the whole area between the glass base FS and the bus electrodes Xb and Yb which are in contact with the transparent electrodes Xt and Yt respectively. Furthermore, the transparent electrodes Xt and Yt may be made of the same material (metal material or the like) as that of the bus electrodes Xb and Yb integrally with the bus electrodes Xb and Yb. An X electrode XE (sustain electrode, one kind of first electrodes) includes the X bus electrode Xb and the X transparent electrode Xt, and a Y electrode YE (scan electrode, one kind of first electrodes) include the Y bus electrode Yb and the Y transparent electrode Yt.
The electrodes Xb, Xt, Yb, and Yt are covered with a dielectric layer DL1. For example, the dielectric layer DL1 is a silicon dioxide film (film of SiO2, film of silicon dioxide) formed by a CVD method. A plurality of address electrodes AE (second electrodes) extending in a direction (second direction D2) orthogonal to the bus electrodes Xb and Yb are provided on the dielectric layer DL1 (on the underside of it in the figure). The address electrodes AE are covered with a dielectric layer DL2, and a surface of the dielectric layer DL2 is covered with a protective layer PL of MgO or the like.
A back plate part 14 facing the front plate part 12 through discharge spaces DS has barrier ribs BR formed in parallel with each other on a glass base RS (second plate). The barrier ribs BR extend in a direction (second direction D2) orthogonal to the bus electrodes Xb and Yb and face the address electrodes AE. In other words, the address electrodes AE are disposed in positions facing the barrier ribs BR. The barrier ribs BR make up the side walls of cells. In addition, phosphors PHr, PHg, and PHb, which emit visible lights of red (R), green (G), and blue (B), respectively, when excited by ultraviolet rays, are coated on the sides of the barrier ribs BR and on the glass base RS between the barrier ribs BR adjacent to each other.
One pixel of the PDP 10 is made up of three cells emitting red, green, and blue light. One cell (a pixel of one color) is formed in an area defined by bus electrodes Xb and Yb and barrier ribs BR. Like this, the PDP 10 has cells disposed in a matrix to display an image and two or more kinds of cells emitting light of colors different from each other arranged alternately. Cells formed along the bus electrodes Xb and Yb make up display lines, which is not particularly shown in the figure.
The PDP 10 is made up by adhering the front plate part 12 and the back plate part 14 to each other so that the protective layer PL and the barrier ribs BR come into contact with each other and encapsulating the discharge spaces DS with discharge gas such as Ne or Xe.
The drivers XDRV, YDRV, and ADRV have lead parts XLD coupled to the bus electrodes Xb (sustain electrodes), lead parts YLD coupled to the bus electrodes Yb (scan electrodes), and lead parts ALD coupled to the address electrodes AE, respectively. The drivers XDRV, YDRV, and ADRV operate as a driver unit driving the PDP 10. The power-supply unit PWR generates power supply voltages Vsc, Vs/2, −Vs/2, Vsa, etc. supplied to the drivers YDRV, XDRV, and ADRV.
The control unit CNT selects a subfield used based on image data R0-7, G0-7, and B0-7, and outputs control signals YCNT, XCNT, and ACNT to the drivers YDRV, XDRV, and ADRV. Subfields are obtained by dividing one field for displaying one screen of the PDP 10, and the number of times of sustain discharge has been set for each subfield. Then, a multiple gradation image is displayed by selecting the subfield used for each of cells C1 constituting pixels.
Furthermore, end parts of the address electrodes AE are positioned between the edge part of the dielectric layer DL1 and the edge part of the glass base RS (dielectric layer DL2 in more detail) and function as connection parts MCT and SCT to couple with a circuit (driver ADRV) applying a voltage to the address electrodes AE. For example, the connection parts SCT are spare connection parts coupled to the driver ADRV when any defect has occurred to connection between the driver ADRV and the connection parts MCT (main connection parts). Only the connection parts MCT are provided at the end parts of the address electrodes AE, and the connection parts SCT need not be provided. The edge part of the glass base RS in the back plate part 14 is positioned more inside than the edge part of the dielectric layer DL2.
The address electrodes AE are provided in positions overlapping the barrier ribs BR, and the transparent electrodes Xt and Yt disposed along the first direction D1 are alternately arranged. Thus, in cells C1 adjacent to each other in the first direction D1 with an address electrode AE in between, the transparent electrodes Yt of both of the cells C1 are not adjacent to both sides of one address electrode AE.
For this reason, when address discharge is generated between the address electrode AE and the transparent electrode Yt of the cell C1 to which attention is paid (in an address period), erroneous discharge can be prevented from occurring in the adjacent cell C1. When address discharge is generated in the discharge space DS of the cell C1 to which attention is paid, the barrier rib BR also acts as part of the dielectric layer, and an electric field between the address electrode AE and the transparent electrode Yt is generated in the discharge space DS (a concave portion of the back plate part 14 shown in
A groove GR is formed on the outer surround part (seal area SL) outside the display area (area surrounded by a thick broken line in the figure) of the glass base RS, and seal material SM such as low-melting glass is disposed in the groove GR. The front plate part 12 is adhered to the back plate part 14 with the seal material SM disposed in the groove GR so that the protective layer PL comes into contact with the barrier ribs BR and the seal area SL. For example, the area of the adhered surface between the seal material SM and the front plate part 12 (protective layer PL in more detail) is made smaller than the area of the opening part of the groove GR.
An exhaust hole EH extending to the outer surface of the glass base RS is provided in an exhaust space ES formed between the seal area SL and the barrier ribs BR. Because of this, the discharge spaces DS of the assembled PDP 10 can be set to a vacuum state, and discharge gas can be encapsulated in the discharge spaces DS.
In general, the address electrodes AE are formed into an electrode pattern using an exposure process after metal microspheres deposited on a surface of the dielectric layer DL1 by a sputtering method or a vapor deposition method. In the present invention, the connection parts MCT and SCT (address electrodes AE) are formed on a plane of the dielectric layer DL1. Since no incline needs to be formed on the edge part of the dielectric layer DL1, the dielectric layer DL1 can be easily formed. Furthermore, since the connection parts MCT and SCT are formed on the plane, the connection parts MCT and SCT are formed accurately and easily with a general manufacturing process by the above vapor deposition method or the like.
As described above, the driver ADRV has the lead parts ALD. In addition, the lead parts ALD have connection parts ACT (plate connection parts) at their ends. The connection parts ACT are coupled with the connection parts MCT provided on the address electrodes AE of the PDP 10 by solder SD or the like. The circuit unit 60 is provided on a flexible printed-circuit board or the like, and the lead parts ALD, XLD, and YLD are formed using a manufacturing process different from that for the electrodes AE, XE, and YE of the PDP 10. For example, the address electrodes AE are formed using a process of depositing metal microspheres on a surface of the dielectric layer DL1, and the lead parts ALD excluding the connection parts ACT are isolated from the dielectric layer DL1.
In order to prevent connections between the connection parts ACT and the connection parts MCT and SCT from becoming difficult because the connection parts MCT and SCT are formed on the dielectric layer DL1, the edge part on the connection parts MCT and SCT side of the glass base RS is positioned more inside than the connection parts MCT and SCT. In other words, the edge part on the connection parts MCT and SCT side of the glass base RS is positioned more inside than the connection parts MCT and SCT, so that the circuit unit 60 (connection parts ACT in more detail) can be easily coupled to the connection parts MCT and SCT.
Furthermore, the lead parts XLD of the driver XDRV have connection parts XCT2 at their ends. The connection parts XCT2 are coupled with the connection parts XCT1 provided on the bus electrodes Xb of the PDP 10 by solder SD or the like. In this embodiment, the edge part on the connection parts XCT1 side of the glass base RS is positioned more inside than the connection parts XCT1, so that the connection parts XCT2 can be easily coupled to the connection parts XCT1.
Furthermore, the lead parts YLD of the driver YDRV have connection parts YCT2 at their ends. The connection parts YCT2 are coupled with the connection parts YCT1 provided on the bus electrodes Yb of the PDP 10 by solder SD or the like. In this embodiment, the edge part on the connection parts YCT1 side of the glass base RS is positioned more inside than the connection parts YCT1, so that the connection parts YCT2 can be easily coupled to the connection parts YCT1.
First, in the reset period RST, a negative voltage decreasing gradually (slope pulse) is applied to the sustain electrodes XE (bus electrodes Xb and transparent electrodes Xt), and a positive voltage is applied to the scan electrodes YE (bus electrodes Yb and transparent electrodes Yt) (
In the address period ADR, a scan voltage becoming an anode at address discharge is applied to the sustain electrodes XE, a scan pulse becoming a cathode at address discharge is applied to the scan electrodes YE, and an address pulse (voltage Vsa) becoming an anode at address discharge is applied to address electrodes AE corresponding to lit cells (
In other words, a voltage larger than the minimum voltage generating discharge (firing voltage) is applied between the scan electrodes YE and the address electrodes AE, and a voltage smaller than the firing voltage is applied between the sustain electrodes XE and the address electrodes AE. Because of this, when address discharge is generated between the address electrode AE and the scan electrode YE of the cell to which attention is paid, erroneous discharge can be prevented from occurring between the sustain electrode XE of the adjacent cell and the address electrode AE. The second address pulse shown in the address electrode AE waveform is applied to select discharge cells of another display line (
In the sustain period SUS, negative and positive sustain pulses are applied to the sustain electrodes XE and the scan electrodes YE, respectively (
In the erase period ERS, a negative pre-erase pulse and a positive high-voltage pre-erase pulse are applied to the sustain electrodes XE and the scan electrodes YE, respectively, and discharge occurs (
As described above, in this embodiment, the connection parts MCT and SCT are formed on a plane of the dielectric layer DL1, so that the address electrodes AE having the connection parts MCT and SCT can be easily formed. In addition, the end part of the dielectric layer DL1 need not be made an incline, so that the dielectric layer DL1 can be easily formed. Furthermore, the edge part on the connection parts MCT and SCT side of the glass base RS is positioned more inside than the connection parts MCT and SCT, so that the circuit unit 60 can be easily coupled to the connection parts MCT and SCT. As a result of this, connection parts coupled with a circuit driving the PDP can be easily formed.
In the above embodiment, an example that one pixel is made up of three cells (red (R), green (G), blue (B)) is described. The present invention is not limited to such an embodiment. For example, one pixel may be made up of four cells or more. Alternatively, one pixel may be made up of cells emitting colors other than red (R), green (G), and blue (B), or one pixel may include cells emitting colors other than red (R), green (G), and blue (B).
In the above embodiment, an example that the end parts of the address electrodes AE are positioned between the edge part of the dielectric layer DL1 and the edge part of the glass base RS is described. The present invention is not limited to such an embodiment. For example, the position of the edge part of the dielectric layer DL1 along the first direction D1 and the positions of the end parts of the address electrodes AE may be set to the same with each other. In addition, the position of the edge part of the glass base FS along the first direction D1, the position of the edge part of the dielectric layer DL1 along the first direction D1, and the positions of the end parts of the address electrodes AE may be set to the same with each other. In this case also, the same effect as the above embodiment can be obtained.
In the above embodiment, an example that three kinds of electrodes of the sustain electrode XE, the scan electrode YE, and the address electrodes AE are formed in the front plate part 12 is described. The present invention is not limited to such an embodiment. For example, two kinds of electrodes of the X-electrodes (second electrodes) which also serve as the address electrodes and the scan electrodes YE (first electrodes) may be formed in the front plate part 12. Alternatively, a Z-electrode assisting sustain discharge between the sustain electrode XE and the scan electrode YE may be provided, and four kinds of electrodes of the sustain electrode XE (one kind of first electrodes), the scan electrode YE (one kind of first electrodes), the address electrodes AE (second electrodes), and the Z-electrode (one kind of first electrodes) may be formed in the front plate part 12. In this case also, the same effect as that of the above embodiment can be obtained.
In the above embodiment, an example that the barrier ribs BR are disposed only in positions facing the address electrodes AE is described. The present invention is not limited to such an embodiment. For example, as shown in
For example, the barrier ribs BR and BR2 are formed by cutting the glass base RS by a sandblast method or the like. The discharge spaces DS may be formed through the processes of coating of paste-state barrier rib material, drying, sandblasting, and baking. Furthermore, the barrier ribs BR and BR2 may be formed with lamination by printing. In this case also, the same effect as that of the above embodiment can be obtained.
In the above embodiment, an example that seal material SM is disposed in the groove GR formed on the outer surround part (seal area SL) of the glass base RS is described. The present invention is not limited to such an embodiment. For example, the seal material SM may be disposed on the seal area SL (outer surround part) without forming the groove GR. In this case, the top surface SL1 of the seal area SL may be formed to about the same height as the bottom of concave portions (discharge space DS) formed between the barrier ribs BR or may be formed to about the same height as the top surface BR1 of the barrier ribs BR. In this case, the same effect as that of the above embodiment can be obtained.
In the above embodiment, an example that the transparent electrodes Xt and Yt are disposed in positions facing each other along the second direction D2 is described. The present invention is not limited to such an embodiment. For example, as shown in
The apical ends SD1 of the transparent electrodes Xt2 coupled with the bus electrodes Xb face the apical ends SD2 of the transparent electrodes Yt2 coupled with the bus electrodes Yb. Furthermore, the transparent electrodes Xt2 and Yt2 are each formed in T-shaped to widen the opposed parts. The shape of the transparent electrodes Xt2 and Yt2 may be a rectangle or a trapezoid. Furthermore, projection parts Ap project from the address electrodes AE toward the transparent electrodes Yt2 of their respective cells and are integrally formed with the address electrodes AE. For this reason, address discharge can be generated in the cell C1 to which attention is paid by applying a voltage between the address electrode AE and the transparent electrode Yt2. In this case also, the same effect as that of the above embodiment can be obtained.
Although the present invention has been described in detail, the above embodiment and its variations are only examples of the present invention, and the present invention is not limited to them. It should be understood that various modifications can be made without departing from the scope of the present invention.
The present invention can be applied to a plasma display panel and a plasma display device.
| Filing Document | Filing Date | Country | Kind | 371c Date |
|---|---|---|---|---|
| PCT/JP2007/000541 | 5/21/2007 | WO | 00 | 10/30/2009 |
