JP3442107B2 - Surface discharge type plasma display panel - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a surface discharge type plasma display panel (PDP) of a matrix display system.

The surface discharge type PDP is suitable for color display by a phosphor, and its applications such as OA equipment and display devices for publications have been expanded and started to spread.

[0003]

2. Description of the Related Art Here, a structure of a surface discharge type PDP will be described with reference to FIG. 1 showing an embodiment of the present invention.

In general, a matrix display type surface discharge type P
In DP, a pair of electrodes (main electrodes for surface discharge) that are adjacent to each other through a discharge gap on one inner surface of a pair of glass substrates 11 and 21 that face each other through a discharge space 30.
A large number of electrode pairs 12 of X and Y are arranged. The electrode pair 12 is covered with a dielectric layer 17 for AC driving, and a protective film 1 made of MgO is formed on the dielectric layer 17.
8 are provided.

On the inner surface of the other glass substrate 21, partition walls 29 partitioning the discharge space 30 into unit light emitting areas EU in the line direction, and address electrodes A for selectively emitting light in the unit light emitting areas EU, Phosphor 28 of a predetermined emission color
R, 28G, 28B are provided. The dielectric layer 17 and the partition 29 are each formed by printing a low melting point glass paste by screen printing and then firing.

At the time of display, for example, first, a voltage exceeding the discharge start voltage is applied between the electrodes X and Y to generate a surface discharge in line units (discharge in the surface direction of the dielectric layer 17). When the surface discharge occurs, wall charges having a polarity opposite to the applied voltage are accumulated in the dielectric layer 17 on the electrodes X and Y, and the wall charges cause the electrodes X and Y in the unit light emitting regions EU to be discharged.
The cell voltage, which is the relative potential difference between the two, drops and the discharge stops. Then, for each line, a discharge erasing pulse is applied to the address electrode A selected according to the display pattern to eliminate unnecessary wall charges.

After that, a discharge sustaining voltage is alternately applied to the electrodes X and Y of each line. As a result, the fluorescent substance 28 is excited by the ultraviolet rays generated by the surface discharge to emit light only in the unit light emitting region EU in which the wall charges have not disappeared. At this time, the brightness of the display is adjusted by appropriately selecting the cycle of applying the sustaining voltage.

[0008]

Conventionally, the electrodes X and Y forming the electrode pair 12 corresponding to each display line are formed.
Were formed in parallel with each other, and the thickness of the dielectric layer 17 covering each electrode pair 12 was uniform over the entire display area. Further, the gap size of the discharge space 30, that is, the protective film 1
8 and the surface of the phosphor 28 on the address electrode A were also uniform over the entire display area. That is, in the conventional surface discharge PDP, the discharge conditions (discharge start voltage) in each unit light emitting region EU are almost the same.

Therefore, when a voltage pulse for sustaining discharge is applied to the electrodes X and Y via the driver circuit, as shown in FIG. 6, during the period in which the applied voltage changes from zero to a predetermined peak value. Therefore, when the applied voltage is within the range of the variation width vj of the discharge start voltage, the surface discharge is generated almost simultaneously in each unit light emitting region EU in the line, and the discharge current is concentrated and flows in a short time. was there.

For example, in a PDP in which the number of dots in one line (one dot is composed of three unit light emitting areas EU) is "640" and the peak value of the discharge sustaining voltage is set to about 180V, the discharge start voltage The minimum and maximum are 160
It was about V and about 170 V, and the peak value of the discharge current of one line was about 10 mA.

As the peak value of the discharge current increases, the load on the driver circuit and the power source increases, and it becomes difficult to increase the size of the PDP. The present invention has been made in view of the above problems and aims to reduce the peak value of the discharge current.

[0012]

[Means for Solving the Problems] P according to the invention of claim 1
In order to solve the above problems, the DP is a pair of substrates 1 facing each other with the discharge space 30 in between, as shown in FIGS. 1 and 2.
1, 21; a plurality of electrode pairs 12 for surface discharge arranged on the one substrate 11; and a dielectric layer 17 covering each electrode pair 12, and a matrix display type surface discharge plasma. In the display panel 1, the electrode pairs 12 are arranged such that the size of the discharge gap is from one end to the other end in the extension direction.
It is formed so as to gradually increase in size .

In the PDP according to the second aspect of the present invention, the thickness of the dielectric layer 17 is set in the extending direction of each electrode pair 12.
It is formed by gradually increasing from one end to the other end . In the PDP according to the invention of claim 3, the pair of substrates 11 and 12 are opposed to each other such that the gap size of the discharge space 30 gradually increases from one end to the other end in the extension direction of each electrode pair 12. Configured.

[0014]

The larger the discharge gap of the electrode pair 12, the higher the discharge start voltage of the surface discharge in each unit light emitting region in the line.

When a voltage pulse having a predetermined crest value is applied to the electrode pair 12, surface discharge occurs in each unit light emitting region in order from the side having a smaller discharge gap in the middle of the applied voltage value approaching the crest value. As a result, the time when the surface discharge occurs in each unit light emitting region is dispersed, and the peak value of the discharge current flowing through the electrode pair 12 becomes small.

The discharge starting voltage becomes higher as the dielectric layer 17 covering the electrode pair 12 becomes thicker, and becomes lower as the gap size of the discharge space 30 becomes larger.

[0017]

1 is an exploded perspective view showing a sectional structure of a portion corresponding to one pixel of a PDP 1 according to a first embodiment of the present invention, and FIG. 2 is a plan view schematically showing an electrode structure of the PDP 1 of FIG. ,
FIG. 3 is a diagram showing the relationship between the applied voltage and the discharge current in the PDP 1 of FIG.

The PDP 1 is a surface discharge type PDP having a three-electrode structure.
And a glass substrate 11 on the display surface H side, an electrode pair 12 including a pair of display electrodes X and Y extending in the display line direction,
A dielectric layer 17 for AC driving, a protective film 18 made of MgO, a glass substrate 21 on the back side, a plurality of barrier ribs 29 defining the gap size of the discharge space 30, and an address electrode A provided between the barrier ribs 29. , And R (red), G (green), B
It is composed of phosphors 28R, 28G, 28B of three primary colors of (blue).

The internal discharge space 30 is partitioned by the partition walls 29 in the line direction for each unit light emitting region EU. In the discharge space 30, neon is used as a discharge gas that emits ultraviolet rays for exciting the phosphors 28R, 28G, 28B. Xenon (1
(About 15 mol%) mixed with several hundreds of Penning gas
It is enclosed so that the gas pressure is about rr.

The display electrodes X and Y are composed of phosphors 28R and 28R.
Since it is arranged on the display surface H side with respect to G and 28B,
It is composed of a strip-shaped transparent conductor 41 and a narrow metal layer 42 for compensating for its conductivity. Transparent conductor 41
Is a Nesa film (tin oxide film), for example, and the metal layer 42 is an aluminum thin film, for example. The transparent conductor 41 and the metal layer 42 are formed by lift-off or photolithography, respectively.

A selective discharge cell (not shown) for selecting display or non-display of the unit light emitting region EU is defined at each intersection of one of the pair of display electrodes X and Y and the address electrode A. A main discharge cell (not shown) for surface discharge is defined near the discharge cell. As a result, of the phosphors 28R, 28G, and 28B that are continuous in the vertical direction in the figure, a portion corresponding to each unit light-emission region EU can be selectively caused to emit light, and full-color display by combining R, G, and B is possible. Is possible.

Each pixel (dot) EG constituting the display screen
Are three unit light emitting regions E having the same area and arranged in the line direction.
Composed of U. The planar shape of the pixel EG is a square advantageous for image quality, and the planar shape of the unit light emitting region EU is a rectangle long in the vertical direction (for example, a size of about 600 μm × 200 μm).

Now, the electrode pair 12 consisting of the display electrodes X and Y
2 is formed such that the dimension of the discharge gap, which is the gap between the electrodes, gradually changes in the extension direction (line direction), as shown in FIG. That is, the linear display electrodes X,
The Y's are not parallel to each other, but are provided symmetrically with respect to the display line L so as to spread from the left side to the right side of the drawing.

The size range of the discharge gap is based on the size of the discharge gap g at the center of the line L, and ±
It is selected in the range of about 10%. For example, when the size of the discharge gap g is 50 μm, the size of the discharge gap g1 on one end side of the line L is 45 μm, and the size of the discharge gap g2 on the other end side is 55 μm.

If the number of pixels EG on the line L is "640", the length of the line L is about 40c.
m, and the difference in the discharge gap between both ends of the line L is about 10 μm, the inclination of the display electrodes X and Y with respect to the line L is actually very small.

In the PDP 1 having the above-described structure, the discharge start voltage of the surface discharge increases as the discharge gap of the electrode pair 12 increases, so that the electrode pair 12 is displayed during display.
When a voltage pulse having a predetermined crest value is applied to, the surface discharge is sequentially delayed as the discharge gap becomes larger in each unit light emitting region EU in the line L while the value of the applied voltage approaches from 0 to the crest value. That is, as shown in FIG. 3, the voltage range v in which the surface discharge occurs is wide, and each unit light emitting area EU is
The start time of the surface discharge of is different.

Therefore, the discharge current flows in the electrode pair 12 in a time-dispersed manner, and the peak value of the discharge current becomes small. The time for the value of the applied voltage to transition from zero to the peak value depends on the resistance value of the display electrodes X and Y and the capacitance between the electrodes, but is usually about 1 ms. Therefore, macroscopically, the one-line unit light emitting region EU emits light almost at the same time.

FIG. 4 shows a PDP 2 according to the second embodiment of the present invention.
3 is a cross-sectional view schematically showing the structure of FIG. In FIG.
The components corresponding to those in FIG. 1 are denoted by the same reference numerals regardless of the difference in shape. The same applies to the following.

The PDP 2 includes a glass substrate 11 on the display surface side,
Electrode pair 12 for surface discharge extending in the line direction, dielectric layer 1
7, glass substrate 21 on the back side, partition walls 29 partitioning the discharge space 30 into unit light emitting regions, address electrodes A, phosphors 2.
8 and a sealing glass 31 for sealing the periphery of the glass substrates 11 and 21. The electrode pair 12 is composed of two display electrodes that are parallel to each other.

The discharge space 30 is filled with a suitable discharge gas. Further, the dielectric layer 1 is formed on the surface of the dielectric layer 17.
Mg of about several hundred Å with the function of preventing the deterioration of No. 7 and lowering the firing voltage by secondary electron emission.
An O film is provided.

Now, in the PDP 2, the dielectric layer 17
Is formed so that its thickness gradually changes in the extension direction (line direction) of the electrode pair 12. That is, the surface of the dielectric layer 17 is a surface inclined with respect to the glass substrate 11, and the thickness d1 on one end side of the electrode pair 12 is, for example, 15 μm.
The thickness d2 on the other end side is, for example, about 25 μm.

The dielectric layer 17 whose thickness changes in this way
Can be formed by adjusting the pressing force of the squeegee during screen printing of low melting point glass.
When the pressing force is increased as compared with the case of printing with a uniform thickness, the thickness is reduced, and when the pressing force is reduced, the thickness is increased.

The thicker the dielectric layer 17 covering the electrode pair 12, the higher the discharge start voltage. Therefore, in the PDP2 as well, as in the case of the PDP1 described above, the surface discharge timing of each unit light emitting region of one line is shifted, so that the peak value of the discharge current is smaller than that of the conventional PDP.

FIG. 5 shows a PDP 3 according to the third embodiment of the present invention.
3 is a cross-sectional view schematically showing the structure of FIG. The PDP 3 includes a pair of glass substrates 11 and 21, an electrode pair 12 for surface discharge extending in the line direction, a dielectric layer 17, barrier ribs 29 arranged at equal intervals in the line direction, address electrodes A, phosphors 28, and sealing glass. 31 and the like.

The electrode pair 12 is composed of two display electrodes parallel to each other, and the dielectric layer 17 has a uniform thickness over the entire display area. M on the surface of the dielectric layer 17
A gO film is provided.

Each partition wall 29 divides the discharge space 30 into unit light emitting regions in the line direction, and defines the gap size of the discharge space 30 by contact with the dielectric layer 17. PD
In P3, the glass substrates 11 and 21 face each other so that the gap size of the discharge space 30 in each unit light emitting region gradually changes in the extension direction of the electrode pair 12 by appropriately selecting the height of each partition wall 29. It is arranged.

Here, the total thickness of the address electrode A and the fluorescent substance 28 thereon is about 15 μm, and the height of the partition wall 29 at the center of the line is, for example, 100 μm. That is, the gap size of the discharge space 30 in the central unit light emitting region is about 85 μm. On the contrary,
The gap dimension h1 of the discharge space 30 on one end side of the line is, for example, about 75 to 80 μm, and the gap dimension h2 of the discharge space 30 on the other end side is, for example, about 90 to 95 μm.

The height of the partition wall 29 can be changed by increasing or decreasing the pressing force of the squeegee in the screen printing of the low melting point glass, or by increasing or decreasing the number of screen printings depending on the site.

The smaller the gap size of the discharge space 30 is, the higher the discharge starting voltage is because the movement of ions is suppressed. Therefore, even in PDP3, the above PDP
As in the case of 1 and 2, the timing of the surface discharge of each unit light emitting region of one line is shifted, so that the peak value of the discharge current is smaller than that of the conventional PDP.

According to the above-described embodiment, the discharge current for displaying one line flows dispersed in time, and its peak value is small. Therefore, the driver circuit corresponding to each electrode pair 12 and the power supply of the entire PDP are provided. It is possible to reduce the burden of. That is, if the power supply capabilities of the driver circuit and the power supply are constant, the number of dots in one line can be increased, and the display surface H can be easily enlarged.

In the embodiment of FIG. 2, when a voltage pulse is applied to a plurality of lines L at the same time, the electrode pair 1 should have a different discharge gap between the lines.
2 may be formed to reduce the peak value of the discharge current for a plurality of lines.

The embodiment of FIG. 2 shows an example in which the size of the discharge gap continuously changes, but the electrode pair 12 is arranged so that the size of the discharge gap changes stepwise in the line direction.
May be formed.

In the embodiment of FIG. 4, an example in which the thickness of the dielectric layer 17 changes continuously is shown, but the dielectric layer 17 is formed so that its thickness changes stepwise in the line direction. You may.

[0044]

According to the present invention, the peak value of the discharge current can be reduced and the load on the drive system can be reduced.

[Brief description of drawings]

FIG. 1 is an exploded perspective view showing a sectional structure of a portion corresponding to one pixel of a PDP according to a first embodiment of the present invention.

FIG. 2 is a plan view schematically showing an electrode structure of the PDP shown in FIG.

FIG. 3 is a diagram showing a relationship between an applied voltage and a discharge current in the PDP of FIG.

FIG. 4 is a sectional view schematically showing a structure of a PDP according to a second embodiment of the present invention.

FIG. 5 is a sectional view schematically showing a structure of a PDP according to a third embodiment of the present invention.

FIG. 6 is a diagram showing a relationship between an applied voltage and a discharge current in a conventional PDP.

[Explanation of symbols]

1, 2 and 3 PDP (surface discharge type plasma display panel) 30 discharge space 11 glass substrate (substrate) 12 electrode pair 17 dielectric layer 21 glass substrate (substrate)

Front page continuation (58) Fields surveyed (Int.Cl. ⁷ , DB name) H01J 11/02 H01J 11/00 G09G 3/28

Claims (3)

(57) [Claims] A pair of board facing 1. A sandwich between discharge space,
A plurality of electrode pairs for surface discharge are arranged in the one board on
When surface discharge type plasma display panel in <br/> Oite matrix display system having a dielectric layer covering the respective electrode pairs, each electrode pair, one end dimension of the extension direction of the discharge gap
A surface discharge type plasma display panel, which is formed so as to gradually increase from one end to the other end . A pair of board facing wherein across the inter-discharge space,
A plurality of electrode pairs for surface discharge are arranged in the one board on
When surface discharge type plasma display panel in <br/> Oite matrix display system having a dielectric layer covering each electrode pair, wherein the dielectric layer is extended thickness of each electrode pair One end of the direction
A surface discharge type plasma display panel, which is formed so as to gradually increase from one end to the other end . A pair of board facing 3. A sandwich between discharge space,
A plurality of electrode pairs for surface discharge are arranged in the one board on
When surface discharge type plasma display panel in <br/> Oite matrix display system having a dielectric layer covering each electrode pair, the pair of base plates, the gap dimension between the discharge space Gradually increase from one end to the other end in the extension direction of each electrode pair.
Surface discharge type plasma display panel characterized by comprising disposed opposite such that.