JP2000305067A - Plasma address display - Google Patents

Abstract

(57) [Summary] [Problem] When the driving of the liquid crystal is repeated, the barrier rib 1
There is a problem that electric charges easily accumulate between the top of the dielectric rib 9 and the dielectric sheet 13, and the liquid crystal near the upper part of the barrier rib 19 burns, thereby deteriorating the display quality. A conductor layer is provided between a dielectric sheet and a top of a barrier rib. This conductor layer 10
By having a portion exposed to the plasma chamber 6, the potential of the plasma chamber 6 and the conductor layer 10 above the barrier ribs are increased.
Can be made the same.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a plasma addressed display device.

[0002]

2. Description of the Related Art Conventionally, as a means for increasing the resolution and contrast of a matrix type electro-optical device using a liquid crystal cell as an electro-optical cell, for example, a liquid crystal display device has a switching device such as a thin film transistor for each pixel. An active matrix addressing method in which elements are provided and driven in a line-sequential manner is generally known.

However, in this case, it is necessary to provide a large number of semiconductor elements such as thin film transistors on a substrate.
In particular, there is a disadvantage that the manufacturing yield is deteriorated when the area is increased. For this reason, recently, instead of a switching element composed of a thin film transistor or the like, Japanese Patent Laid-Open No.
Japanese Patent Application Publication No. 6 (1994) and the like have proposed a system using a switch based on plasma discharge.

FIG. 5 is a partial sectional configuration diagram of a conventional plasma addressed display device. As shown in FIG. 5, the plasma addressed display device includes a liquid crystal cell 11 and a plasma cell 12.
And a dielectric panel 13 interposed therebetween. The liquid crystal cell 11 includes a plurality of data electrodes (not shown) extending in the left-right direction provided at predetermined intervals in a direction perpendicular to the paper surface of FIG.
And a liquid crystal layer 14 filled with liquid crystal between the data electrodes. The plasma cell 12 has a glass substrate 15, a plasma chamber 16, a cathode electrode 17, an anode electrode 18, and a barrier rib 19. On the glass substrate 15, a cathode electrode 17 and an anode electrode 18 are formed in a striped pattern extending in a direction perpendicular to the plane of FIG. Further, barrier ribs 19 made of a dielectric reaching the lower surface of the dielectric sheet 13 are formed in a stripe pattern. An ionizable gas is sealed in the plasma chamber 16 individually sealed by the dielectric sheet 13, the glass substrate 15, and the barrier rib 19. As this gas,
For example, helium, neon, argon, xenon, or a mixed gas thereof is used.

In the above configuration, for example, when a predetermined voltage is applied to the cathode electrode 17 and the anode electrode 18 corresponding to the plasma chamber 16 shown in FIG. 5, the cathode electrode 17 and the anode electrode 18 serve as a cathode and an anode, respectively. In operation, the gas in the portion of the plasma chamber 16 is selectively ionized to generate a plasma discharge, and the inside thereof is maintained at a substantially anode potential. In this state, when a data voltage is applied to the data electrode, the data voltage is written to the liquid crystal layer 14 of the pixel corresponding to the plasma chamber 16 via the dielectric sheet 13. When the plasma discharge ends, the plasma chamber 16 becomes a floating potential, and the liquid crystal layer 14 of the corresponding pixel
Is held until the next writing period (for example, after one frame). At this time, the plasma chamber 16 functions as a sampling switch, and the liquid crystal layer 1 of each pixel is
4 functions as a sampling capacitor.

Since the liquid crystal operates by the data voltage written from the data electrode to the liquid crystal layer 14 of each pixel, display is performed in pixel units. Therefore, a two-dimensional image can be displayed by sequentially scanning a pair of plasma chambers in which a data voltage is written to the liquid crystal layers 14 of a plurality of pixels arranged in the column direction by generating a plasma discharge in the row direction. .

[0007]

When the above-described plasma addressed display device is driven, a discharge channel is selectively scanned in a line-sequential manner, and a predetermined image signal is supplied to the data electrode in synchronization with the scan. As a result, electric charges corresponding to the signal voltage are stored in the dielectric sheet 13 of each discharge channel. When the top of the barrier rib 19 shown in FIG. 5A is enlarged, it has irregularities as shown in FIG. 6, and has a slight gap between itself and the dielectric sheet 13. When the plasma address display device is driven to selectively scan the discharge channel line-sequentially and supply a predetermined image signal to the data electrode in synchronization with this, the discharge channel is also provided between the dielectric sheet 13 and the barrier rib 19. The electric charge flows into the dielectric sheet 13 above the barrier rib 19 and the electric charge is also charged.

The electric charge flowing into the minute space on the barrier rib 19 is greatly affected by the electric potential of the dielectric sheet 13 of the adjacent channel and the electric charge written in the previous frame. Therefore, when the discharge channel is driven line-sequentially and the dielectric sheet 13 is charged with the image signal voltage, the upper portion of the barrier rib 19 is not completely rewritten but is written in a state where a DC offset is applied. Will be performed. That is, when the driving of the liquid crystal is repeated, electric charges easily accumulate between the top of the barrier rib 19 and the dielectric sheet 13, and the barrier rib 19
There is a problem in that image sticking occurs in the liquid crystal near the upper part of the display, and the display quality deteriorates.

[0009]

According to a first aspect of the present invention, there is provided a plasma addressed display device including an electro-optical cell and a plasma cell which are stacked via a dielectric sheet, wherein the plasma cell includes a glass substrate and a plasma substrate. A stripe-shaped barrier rib for partitioning a plasma chamber is provided between the dielectric sheet and the dielectric sheet, and a conductor layer is provided between the dielectric sheet and the barrier rib.

[0010] In the invention described in claim 2, the conductor layer is formed of N
It contains at least one of i, Al, Ag, Au, Cu, and Pt.

The invention according to claim 3 is characterized in that the thickness of the conductor layer is 1 μm or more and 30 μm or less.

According to a fourth aspect of the present invention, a potential detecting means for detecting the potential of the conductor layer is provided, and the potential output from the plasma driving circuit or the liquid crystal driving circuit is adjusted by the potential detected by the potential detecting means. It is characterized by having means.

According to a fifth aspect of the present invention, there is provided a semiconductor device comprising: potential detecting means for detecting a potential of the conductor layer; and means for applying a predetermined voltage to the conductor layer based on the potential detected by the potential detecting means. Features.

The operation of the present invention will be described below.

When a discharge channel is selected, a constant voltage is applied to the discharge electrode, and the inside of the channel is filled with plasma, charged particles also flow into the minute gap between the top of the barrier rib and the dielectric sheet.

According to the first aspect of the present invention, since the conductor layer is provided between the dielectric sheet and the barrier rib, the potential of the conductor layer always becomes equal to the potential of the plasma chamber.
Therefore, no excess charge accumulates at the top of the barrier rib, and the potential of the top of the barrier rib is always equal to the potential of the plasma chamber regardless of the magnitude or sign of the liquid crystal drive voltage. Therefore, it is possible to prevent image sticking of the liquid crystal near the upper part of the barrier rib.

According to the second aspect of the present invention, the conductor layer is made of Ni,
By including at least one of Al, Ag, Au, Cu, and Pt, a conductor layer having a low resistance value can be used. When the resistance value of the conductor layer is large, a difference occurs between the potential of the plasma chamber and the potential of the top of the barrier rib, and the potential of the top of the barrier rib becomes unstable, resulting in burning of the liquid crystal layer.

According to the third aspect of the present invention, by setting the thickness of the conductor layer to 1 μm or more, disconnection (discontinuity) of the conductor layer is caused.
Can be prevented, and when the thickness is 30 μm or less, cracks due to thermal stress with the barrier rib material can be prevented.

In the plasma chamber, a small spatial potential distribution is generated due to the plasma density distribution. In order to prevent image sticking of the liquid crystal on the barrier rib, it is necessary to directly detect the potential of the conductive layer and control the liquid crystal voltage or the plasma driving voltage in accordance with the potential.

According to the fourth aspect of the present invention, since the potential of the conductive layer is directly detected by the potential detection circuit, the potential of the conductive layer can be measured accurately. From the measured potential, the liquid crystal driving circuit or The voltage from the plasma driving circuit can be controlled to prevent burn-in of the liquid crystal layer.

According to the fifth aspect of the present invention, since the potential of the conductive layer is directly detected by the potential detecting circuit, the potential of the conductive layer can be accurately measured, and the offset voltage is applied to the conductive layer from the measured potential. By applying the correction voltage that cancels out, it is possible to control the potential at the top of the barrier rib more easily than controlling the plasma discharge voltage and the liquid crystal drive voltage. This makes it possible to make the charged particle distribution in the plasma chamber uniform. In addition, it is possible to prevent burn-in of the liquid crystal.

[0022]

(Embodiment 1) Embodiment 1 will be described with reference to the drawings. FIG. 1 is a partial cross-sectional configuration diagram of a plasma addressed display device of the present invention. As shown in FIG. 1, the plasma addressed display device has a flat panel structure in which a liquid crystal cell 1, a plasma cell 2, and a dielectric sheet 3 interposed therebetween are stacked. The liquid crystal cell 1 includes a plurality of data electrodes (row electrodes) provided at predetermined intervals in a direction perpendicular to the paper surface of FIG. 1 and extending in the left-right direction, and a liquid crystal filled between the dielectric sheet 3 and the data electrodes. And a layer 4.

The plasma cell 2 has a glass substrate 5, a plasma chamber 6, a cathode electrode 7, an anode electrode 8, and a barrier rib 9. On the glass substrate 5, a cathode electrode 7 and an anode electrode 8 are formed in a stripe pattern extending in the direction perpendicular to the paper of FIG. Further, barrier ribs 9 are formed on the lower surface of the dielectric sheet 3 in a stripe pattern. A conductor layer 10 is provided between the dielectric sheet 3 and the top of the barrier rib 9. This conductor layer 10
By having a portion exposed to the plasma chamber 6, the potential of the plasma chamber 6 and the conductor layer 10 above the barrier ribs are increased.
Can be made the same.

An ionizable gas is sealed in the plasma chamber 6, which is individually sealed by the dielectric sheet 3, the glass substrate 5, and the barrier rib 9. As this gas,
For example, helium, neon, argon, xenon, or a mixed gas thereof is used.

In the above configuration, when a predetermined voltage is applied to the cathode electrode 7 and the anode electrode 8, the cathode electrode 7 and the anode electrode 8 act as a cathode and an anode, respectively, and the gas in the plasma chamber 6 is ionized. As a result, a plasma discharge is generated, and the inside of the plasma chamber 6 is maintained at a substantially anode potential (normally-several volts). In this state, when a data voltage is applied to the data electrode, the data voltage is written to the liquid crystal layer 4 of the pixel corresponding to the plasma chamber 6 via the dielectric sheet 3. When the plasma discharge ends, the plasma chamber 6 becomes a floating potential and the liquid crystal layer 4 of the corresponding pixel
Is held until the next writing period (for example, after one frame). At this time, the plasma chamber 6 functions as a sampling switch, and the liquid crystal layer 4 of each pixel functions as a sampling capacitor.

Since the liquid crystal operates by the data voltage written from the data electrode to the liquid crystal layer 4 of each pixel, display is performed in pixel units. Therefore, a two-dimensional image can be displayed by sequentially scanning in a row direction a pair of plasma chambers that generate a plasma discharge and write a data voltage to the liquid crystal layer 4 of a plurality of pixels arranged in the column direction in the row direction. .

In the present embodiment, the conductor layer 10 is formed, and the potential of the conductor layer 10 matches the potential in the plasma chamber 6. Therefore, the plasma discharge ends and the plasma chamber 6
Is a floating potential (a potential at which the data signal of the data electrode is not written in the liquid crystal), a voltage that causes burn-in to the liquid crystal is not applied to the liquid crystal layer above the barrier rib 9. Further, when the plasma discharge is generated and the plasma chamber 6 is substantially at the anode potential, an extra offset voltage is not applied to the liquid crystal layer above the barrier ribs 9, so that the burn-in of the liquid crystal can be suppressed. In a display device having a large number of plasma chambers 6, the plasma chamber 6 has a floating potential (a potential at which a data signal is not written to the liquid crystal) in most of one frame period. The voltage at which image sticking occurs is not applied.

As the conductor layer 10, Ni, Al, Ag,
A conductive paste containing at least one of Au, Cu, and Pt is obtained by printing and firing. As an example, when a paste containing only Ni is used, by firing in air at a firing temperature of 580 ° C. for 30 minutes, a resistance of 20 μm and a small resistance of 40 mΩ / □ can be realized.

The problem that a potential difference between the conductor layer 10 and the discharge channel occurs due to a voltage drop due to the resistance of the conductor layer 10 and an offset voltage is applied can be suppressed by using a low-resistance material for the conductor layer 10. Can be prevented from burning.

In the present embodiment, the conductor layer 1
The thickness of 0 is desirably 1 to 30 μm. 1 μm
If less, the conductor layer will not be continuous and will be disconnected,
If it exceeds 30 μm, cracks occur or the conductor layer peels off due to thermal stress with the barrier rib material.

Also in the plasma addressed display device of the present embodiment, in the case where burn-in occurs due to the wiring resistance value, driving conditions, etc., the burn-in can be prevented by the second and third embodiments.

(Embodiment 2) Next, Embodiment 2 will be described with reference to FIG. A description of the same configuration as in the first embodiment will be omitted. In the present embodiment, as shown in FIG.
0 potential detection circuit is connected. Then, a DC voltage offset is superimposed on the data voltage applied from the data electrode according to the potential detected by the potential detection circuit. Conductor layer 1
If the potential of 0 is −10 V, the liquid crystal driving voltage is −1.
A 0 V offset voltage is superimposed, and control is performed so that the liquid crystal voltage is inverted with reference to −10 V. Burn-in caused by applying an extra offset voltage to the liquid crystal layer can be suppressed by canceling out the offset voltage applied to the liquid crystal layer. By driving in this way, the burn-in of the liquid crystal is completely eliminated. Here, the offset voltage is not always kept constant, but the potential is always detected by the potential detection circuit of the conductor layer 10 and the offset amount is controlled in accordance therewith, whereby the burn-in elimination effect is dramatically improved. Further, the voltage applied to the plasma driving circuit may be adjusted.

(Embodiment 3) Next, Embodiment 3 will be described with reference to FIG. A description of the same configuration as in the first embodiment will be omitted. In the present embodiment, as shown in FIG.
0 potential detection circuit is connected. Then, a DC voltage is applied to the conductor layer 10 according to the potential detected by the potential detection circuit. For example, if the potential of the conductor layer 10 is +10 V,
A voltage of −10 V is applied to the conductor layer 10. FIG. 4 shows an example of the relationship between the detection potential in the conductor layer 10 and the applied voltage thereafter. As shown in the figure, a positive voltage is applied when the potential of the conductor layer is negative, and a negative voltage is applied when the potential is positive. As shown in FIG. 4, if the potential of the conductor layer 10 is +10 V, a voltage of −10 V is applied to the conductor layer 10.
This amount is determined by the driving condition of the liquid crystal layer 4 on the plasma channel. For example, FIG. 4 shows a case of driving in which burn-in can be prevented when the voltage of the dielectric sheet is 0 V.

By performing such control, the image sticking of the liquid crystal layer 4 on the barrier rib 9 is completely eliminated. Also,
When the voltage applied to the conductor layer 10 is higher than the anode potential of the plasma channel, for example, -10 V, the distribution of charged particles in the plasma channel changes near the barrier rib. In the plasma chamber, among the charged particles, electrons are very small particles,
Since the probability of collision with gas atoms is low, they are uniformly distributed in the plasma chamber. On the other hand, ions are large particles,
It is difficult to diffuse in the plasma chamber, and the density near the barrier ribs away from the cathode decreases. In this case, when about -10 V is applied to the conductor layer, the ions are attracted to the conductor layer 10 having a higher potential than the space potential, and the bias of the charged particles in the plasma chamber can be reduced. It is possible to eliminate unevenness in writing.

The dielectric sheet 3 is sometimes called an intermediate sheet, a microsheet or a thin intermediate layer. Further, the barrier rib 9 may be called a partition wall or a dielectric wall.

[0036]

According to the first aspect of the invention, since the conductor layer is provided between the dielectric sheet and the barrier rib, the potential of the conductor layer always becomes equal to the potential of the plasma chamber. Therefore, no excess charge accumulates at the top of the barrier rib, and the potential of the top of the barrier rib is always equal to the potential of the plasma chamber regardless of the magnitude or sign of the liquid crystal drive voltage. Therefore, it is possible to prevent image sticking of the liquid crystal near the upper part of the barrier rib.

According to the invention of claim 2, the conductor layer is made of Ni,
By including at least one of Al, Ag, Au, Cu, and Pt, a conductor layer having a low resistance value can be used. When the resistance value of the conductor layer is large, a difference occurs between the potential of the plasma chamber and the potential of the top of the barrier rib, and the potential of the top of the barrier rib becomes unstable, resulting in burning of the liquid crystal layer.

According to the third aspect of the present invention, by setting the thickness of the conductor layer to 1 μm or more, disconnection (discontinuity) of the conductor layer is caused.
Can be prevented, and when the thickness is 30 μm or less, cracks due to thermal stress with the barrier rib material can be prevented.

According to the fourth aspect of the present invention, since the potential of the conductive layer is directly detected by the potential detecting circuit, the potential of the conductive layer can be measured accurately. From the measured potential, the liquid crystal driving circuit or The voltage from the plasma driving circuit can be controlled to prevent burn-in of the liquid crystal layer.

According to the fifth aspect of the present invention, since the potential of the conductive layer is directly detected by the potential detecting circuit, the potential of the conductive layer can be accurately measured, and the offset voltage is applied to the conductive layer from the measured potential. By applying the correction voltage that cancels out, it is possible to control the potential at the top of the barrier rib more easily than controlling the plasma discharge voltage and the liquid crystal drive voltage. This makes it possible to make the charged particle distribution in the plasma chamber uniform. In addition, it is possible to prevent burn-in of the liquid crystal.

[Brief description of the drawings]

FIG. 1 is a sectional view of a plasma addressed display device according to a first embodiment.

FIG. 2 is a sectional view of a plasma addressed display device according to a second embodiment.

FIG. 3 is a sectional view of a plasma addressed display device according to a third embodiment.

FIG. 4 is a diagram showing a relationship between a detection potential in a conductor layer 10 and a subsequently applied voltage in the third embodiment.

FIG. 5 is a sectional view of a conventional plasma addressed display device.

FIG. 6 is an enlarged view of a portion A in FIG. 5;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1, 11 Liquid crystal cell 2, 12 Plasma cell 3, 13 Dielectric sheet 4, 14 Liquid crystal layer 5, 15 Glass substrate 6, 16 Plasma chamber 7, 17 Cathode electrode 8, 18 Anode electrode 9, 19 Barrier rib 10 Conductive layer

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 2H089 HA36 QA02 QA16 5C040 FA09 GA03 GB14 GF13 GK20 KA01 KB17 MA07 5C094 AA03 AA36 AA53 AA54 AA55 BA43 CA19 DA13 DB10 EA10 EC03 EC04 FA02 FB02 FB12 GA10 JA08

Claims (5)

[Claims] 1. A plasma addressed display device comprising an electro-optical cell and a plasma cell stacked via a dielectric sheet, wherein the plasma cell defines a plasma chamber between a glass substrate and the dielectric sheet. A plasma addressed display device comprising stripe-shaped barrier ribs, wherein a conductor layer is provided between the dielectric sheet and the barrier ribs. 2. The conductor layer is made of Ni, Al, Ag, Au,
2. The plasma addressed display device according to claim 1, comprising at least one of Cu and Pt. 3. The conductor layer has a thickness of 1 μm or more and 30 μm or more.
A plasma addressed display device characterized by the following. 4. A potential detecting means for detecting a potential of the conductor layer, and a means for adjusting a potential output from a plasma driving circuit or a liquid crystal driving circuit based on the potential detected by the potential detecting means. 2. The plasma addressed display device according to claim 1, wherein: 5. A potential detecting means for detecting a potential of the conductor layer, wherein the potential detected by the potential detecting means is
2. The plasma addressed display device according to claim 1, further comprising means for applying a predetermined voltage to the conductor layer.