JPH1140063A - Plasma display panel - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress a voltage drop in a plasma display panel to the utmost while holding the numerical aperture of its cells uniform. SOLUTION: A plasma display panel 1 comprises a pair of substrates holding discharge space therebetween, the front substrate of which has on its inner surface a pair of strip electrodes X and Y each made of a transparent conductive film 41 and a metal film 42 at every matrix display line. The width W of the metal film 42 of one electrode X is gradually decreased and that of the metal film 42 of the other electrode Y is gradually increased in every line from one end to the other of the screen region E1 in the line direction such that they keep a constant distance D2 therebetween irrespective of their positions in the line direction.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a surface discharge type plasma display panel (PDP).
l) concerning.

[0002] Surface discharge type PDPs have been commercialized as color display devices for televisions and computer systems. Although the screen size has reached 42 inches, a larger screen is desired in the market.

[0003]

2. Description of the Related Art As is well known, a PDP is a flat type display device comprising a pair of substrates provided with components such as electrodes, and a surface discharge type PDP is provided with an anode and a cathode in a discharge for securing luminance. This is a PDP in which a pair of main electrodes are arranged in parallel on the same substrate to generate surface discharge along the substrate surface. Although a structure in which the main electrodes are shared between adjacent lines is also known, basically, a pair of main electrodes is arranged for each line, and the total number thereof is 2n.
(N is the number of lines). In the surface discharge type PDP, the phosphor layer for color display is provided on the other substrate opposite to the substrate provided with the main electrode, so that deterioration of the phosphor layer due to ion bombardment during discharge can be reduced. it can. An arrangement in which the phosphor layer is disposed on the rear substrate is called "reflection type", and an arrangement in which the phosphor layer is disposed on the front side substrate is called "transmission type". For higher luminance, a reflection type in which the front surface of the phosphor layer is a light emitting surface is advantageous.

In a reflection type surface discharge type PDP, a main electrode is disposed on a front substrate. In order to avoid blocking of the display light, the main electrode needs to be a transparent electrode. But I
The conductivity of transparent conductive materials such as TO and Nesa is insufficient for practical use. Therefore, in a surface discharge type PDP, a laminate of a transparent conductive film and a metal film for supplementing conductivity is provided as a main electrode.

FIG. 5 is a plan view showing the structure of a main electrode pair of a conventional surface discharge type PDP 90. In the PDP 90, a pair of band-shaped main electrodes Xj,
Yj are arranged. Each of the main electrodes Xj and Yj is composed of a transparent conductive film 410 and a metal film 420 having a smaller width. The transparent conductive film 410 and the metal film 420 have a linear band shape inside the screen area E1 in which cells are arranged vertically and horizontally. In order to minimize the amount of light shielding, the metal film 420 is overlapped on the transparent conductive film 410 so as to approach the edge opposite to the gap (surface discharge gap) g between the transparent conductive films 410. Further, the metal film 4 of each main electrode Xj, Yj
Numeral 20 extends from the screen area E1 to the vicinity of the edge of the substrate so as to be connected to an external driving circuit, and extends outside the screen area E1 into a shape suitable for wiring (such as a bent band) outside the screen area E1. It is patterned.

Conventionally, the width w of the metal film 420 has been constant within the range of the screen area E1. Metal film 420
The distance d2 between the two and the dimension d1 of the surface discharge gap g were also constant.

[0007]

By the way, in the PDP, as the screen becomes larger, the influence of the voltage drop due to the resistance of the electrodes becomes more serious. That is, a decrease in the discharge intensity (luminance) due to a decrease in the voltage applied to the cell (voltage drop) becomes remarkable.

To reduce the voltage drop, the metal film 42
What is necessary is just to make 0 larger and lower resistance. However, the metal film 42
If the width of 0 is increased, the “aperture ratio”, which is the ratio of the non-light-shielding portion in the cell, decreases, and the luminous efficiency decreases.

An object of the present invention is to reduce the voltage drop as much as possible while ensuring the uniformity of the cell aperture ratio.

[0010]

A PDP according to the first aspect of the present invention.
A pair of strip-shaped electrodes is arranged for each matrix display line on the inner surface of the front substrate in a pair of substrates sandwiching a discharge space, and each of the electrodes comprises a transparent conductive film and a metal film.
DP, in the screen area, the width of the metal film of one electrode of each of the lines gradually decreases from one end to the other end in the line direction, and conversely, the width of the metal film of the other electrode The width is gradually increased, and the interval between the metal films of the pair of electrodes is configured to be constant regardless of the position in the line direction.

In the PDP according to the present invention, the edges of the transparent conductive film and the metal film constituting each of the main electrodes, which are farther from the surface discharge gap, are substantially parallel, and the metal film is The transparent conductive film is superimposed on the side far from the surface discharge gap.

In the PDP according to a third aspect of the present invention, in each of the lines, the width of at least one of the transparent conductive films is changed on a cell-by-cell basis so that the distance between the transparent conductive films of the pair of electrodes does not vary in the line direction. It is uniform.

[0013]

FIG. 1 is a block diagram of a plasma display device 100 according to the present invention. Plasma display device 10
0 is a matrix type color display device AC
It comprises a driving type PDP 1 and a driving unit 80 for selectively lighting cells constituting a screen (screen), and is used as a wall-mounted television receiver, a monitor of a computer system, or the like.

The PDP 1 is a surface discharge type PDP in which a pair of sustain electrodes (main electrodes) X and Y are arranged in parallel. Each cell has a three-electrode structure in which the sustain electrodes X and Y and the address electrode A correspond to each other. It has an electrode matrix.
In the screen area E1, the sustain electrodes X and Y extend in the line direction (horizontal direction) of the screen, and the address electrodes A are data electrodes for selecting cells in column units, and extend in the column direction (vertical direction). . The sustain electrode X of each line is electrically shared, and is connected to the drive unit 86 at one end (left end in the drawing) in the line direction. On the other hand, the sustain electrode Y of each line is independently connected to the drive unit 86 at the other end (right end in the drawing) in the line direction, and is used as a scan electrode for selecting cells in line units. The address electrode A is a data electrode for selecting a cell in a column unit, and extends in the column direction (vertical direction).

The drive unit 80 includes a controller 81,
It has a frame memory 82, an X driver circuit 86, a Y driver circuit 87, an address driver circuit 88, and a power supply circuit (not shown). Multi-valued video data DR, DG, and DB indicating the RGB luminance level (gray level) of each pixel are input to the drive unit 80 from an external device together with various synchronization signals. Video data DR, DG, DB
Are once stored in the frame memory 82, converted into sub-frame data Dsf for each color by the controller 81, and stored in the frame memory 82 again. The subframe data Dsf is a set of binary data indicating whether or not the cells need to be lit in each subframe obtained by dividing one frame for gradation display. The X driver circuit 86 is responsible for applying a voltage to the sustain electrode X, and the Y driver circuit 87 is responsible for applying a voltage to the sustain electrode Y. The address driver circuit 88 selectively applies an address voltage to the address electrode A according to the sub-frame data Dsf transferred from the frame memory 82.

FIG. 2 is a perspective view showing the internal structure of the PDP 1 of the present invention. In the PDP 1, a pair of sustain electrodes X and Y are arranged for each line L, which is a horizontal cell row of the screen, on the inner surface of the glass substrate 11 on the front side of the substrate pair sandwiching the discharge space 30. Sustain electrode X, Y
Are each composed of a transparent conductive film 41 and a metal film 42 for reducing the resistance value.
7. An MgO film 18 is deposited on the surface of the dielectric layer 17. Dielectric layer 17 and MgO film 18
It has excellent light transmission. Note that the sustain electrodes X, Y,
The substrate on which the laminate of the dielectric layer 17 and the protective film is formed is called a substrate structure. On the inner surface of the glass substrate 21 on the back side, a base layer 22, an address electrode A, an insulating layer 24, partition walls 29, and phosphor layers 28R, 28G, 28B of three colors (R, G, B) for color display. Is provided. Each partition 29 is linear in plan view. These partitions 2
9, the discharge space 30 is partitioned in the line direction for each sub-pixel (unit light emitting area), and the gap size of the discharge space 30 is defined to a constant value (about 150 μm).
The discharge space 30 is filled with a discharge gas obtained by mixing a small amount of xenon with neon. The phosphor layers 28R, 28G,
28B is locally excited by ultraviolet rays generated by the discharge and emits visible light of a predetermined color.

One pixel of the display is composed of three sub-pixels arranged in the line direction. The structure within each sub-pixel is a cell. Since the arrangement pattern of the partition walls 29 is a stripe pattern, a portion of the discharge space 30 corresponding to each column is continuous in the column direction across all the lines. The emission colors of the sub-pixels in each column are the same.

The PDP 1 having the above-described structure is composed of each glass substrate 1
Predetermined components are separately provided for the substrates 1 and 21 to produce front and rear substrate structures, and the two substrate structures are overlapped to seal the periphery of the facing gap, and the inside is filled with exhaust gas and discharge gas. It is manufactured by a series of steps. In manufacturing the front substrate structure, the sustain electrodes X and Y, which are the features of the present invention, are formed by patterning an ITO thin film to form a transparent conductive film 41, and then forming a three-layer structure of, for example, chromium-copper-chromium. It is formed by depositing a metal thin film on almost the entire surface of the glass substrate 11 and patterning it by photolithography.

FIG. 3 is a plan view showing the structure of the main electrode pair of the present invention. In the screen area E1, the sustain electrodes X,
Each transparent conductive film 41 of Y has a fixed width (for example, 300
μm) and are parallel to each other. And
The dimension D1 of the surface discharge gap g is constant over the entire length of the line. On the other hand, the width W of the metal film 41 changes along the line direction. In the PDP 1, the thickness gradually increases from the power supply side connected to the drive unit 80 to the opposite side. For example, if the screen is 42 inches in size, the line length is about 960 mm, and the width W is
Is about 100 μm, and about 150 μm on the opposite side. Each metal film 42 is disposed on the transparent conductive film 41 so as to be closer to an edge farther from the surface discharge gap g. The edge of each metal film 42 on the side far from the surface discharge gap g is parallel to the transparent conductive film 41, and the edge on the side near the surface discharge gap g is slightly inclined with respect to the line direction. Edges of the pair of metal films 42 closer to the surface discharge gap g are parallel to each other. That is, the distance D between the metal films 42
2 is constant over the entire length of the line, and the aperture ratio of cells in the line is uniform.

Here, assuming that the minimum value of the width W of the metal film 42 is the conventional width w, the metal film 4 has an increased width W.
2 is increased, and the sustain electrodes X,
The overall resistance of Y will decrease. Further, since the width W of the metal film 42 of the sustain electrode Y increases as the distance from the power supply side increases, the transition from the counter discharge with the address electrode A to the surface discharge with the sustain electrode X in the addressing shifts from the power supply side. A distant cell occurs in the same manner as a cell near the power supply side, and the addressing reliability is increased.

FIG. 4 is a diagram showing a modification of the main electrode pair structure. In the example of FIG. 4, the sustain electrodes Xb and Yb include a substantially linear band-shaped transparent conductive film 41b whose edge near the surface discharge gap g ′ is patterned in a stepwise manner so that the width changes in cell units. And a metal film 42b patterned so as to gradually become thinner from the power supply side to the opposite side. Since the width D1i (i is the cell number) of the surface discharge gap g 'is slightly different for each cell, the discharge start timing is slightly shifted between the cells when a plurality of cells are turned on, and the temporal concentration of the discharge current is reduced. You. The voltage drop is reduced by lowering the peak value of the discharge current. It is sufficient that the discharge start timing is appropriately non-uniform, and it is not necessary that the widths D1i of the surface discharge gaps g 'in all cells be different from each other.

In the case of the structure shown in FIG. 4, as a sustain pulse alternately applied to the sustain electrodes Xb and Yb to generate a surface discharge, a step-like pulse whose peak value increases stepwise is effective. In a cell where discharge easily occurs, discharge occurs at a stage where the peak value is small. When the discharge occurs, the effective voltage decreases due to the charging of the wall charges, so that no discharge occurs even if the peak value subsequently increases. Even in a cell in which no discharge has occurred, discharge occurs when the peak value becomes large. In other words, the step-like pulse can reliably generate surface discharge in all cells even if the discharge start condition is intentionally made non-uniform in order to reduce the voltage drop.

According to the above-described embodiment, the metal films 42, 4
The metal films 42, 42 are formed such that the edges near the surface discharge gaps g, g 'in 2b are oblique to the line direction.
Since the width W of b is changed, the shape of the opening of each cell becomes substantially uniform. By making the edges closer to the surface discharge gaps g and g 'parallel and skewing the edges farther from the surface discharge gaps g and g', the width W can be changed while keeping the interval between the metal films constant. In this case, the shape of the opening of the cell is greatly different between the end and the center of the line.

[0024]

According to the first to third aspects of the present invention,
Voltage drop can be reduced while ensuring uniformity of cell aperture ratio.

[Brief description of the drawings]

FIG. 1 is a block diagram of a plasma display device according to the present invention.

FIG. 2 is a perspective view showing the internal structure of the PDP of the present invention.

FIG. 3 is a plan view showing a structure of a main electrode pair of the present invention.

FIG. 4 is a view showing a modification of the main electrode pair structure.

FIG. 5 is a plan view showing a structure of a main electrode pair of a conventional surface discharge type PDP.

[Explanation of symbols]

 Reference Signs List 1 PDP (matrix display device) 11 Glass substrate (front side substrate) 30 Discharge space 41, 41b Transparent conductive film 42, 42b Metal film D1 Interval between transparent conductive films D2 Interval between metal films g, g 'Surface discharge gap L Line W Width X, Y Sustain electrode (main electrode)

Claims (3)

[Claims] 1. A plasma display comprising a pair of strip-shaped electrodes arranged on the inner surface of a front-side substrate of a pair of substrates sandwiching a discharge space, for each line of a matrix display, each of said electrodes comprising a transparent conductive film and a metal film. In the panel, in the screen area, the width of the metal film of one electrode of each of the lines gradually decreases from one end to the other end in the line direction, and conversely, the width of the metal film of the other electrode is reduced. A plasma display panel, wherein the width is gradually increased, and a distance between the metal films of the pair of electrodes is constant regardless of a position in a line direction. 2. An edge of the transparent conductive film and the metal film constituting each of the main electrodes on a side far from the surface discharge gap is substantially parallel, and the metal film is on a side far from the surface discharge gap. 2. The plasma display panel according to claim 1, wherein the plasma display panel is overlapped with the transparent conductive film. 3. In each of the lines, by changing the width of at least one transparent conductive film on a cell-by-cell basis,
3. The plasma display panel according to claim 1, wherein a distance between the transparent conductive films of the pair of electrodes is not uniform in a line direction.