JP2001265260A - Plasma address display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a plasma address display device in which lowering of display quality caused by a crosstalk phenomenon is suppressed and prevented. SOLUTION: A display device 100 having a plurality or pixel areas 117 arranged in a matrix form, has a display medium layer 105 arranged between a 1st substrate 103 and a dielectric layer 107, and a 2nd substrate 116 arranged to face the display medium layer 105 via the dielectric layer 107, and is provided with plasma channels 112 extending in the direction of row between the dielectric layer 107 and the 2nd substrate 116. The 1st substrate 103 has a counter electrode 104 on the side of the display medium layer 105, and the 2nd substrate 116 has scanning electrodes 109 extending in the direction of row in parallel with the plasma channels 112 and signal electrodes 108 extending in the direction of column different from the scanning electrodes 109. Since it is unnecessary to apply a different voltage to the counter electrode 104 in column units, crosstalk due to a lateral field is prevented from occurring.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a plasma addressed display device, and more particularly to a plasma addressed display device suitably used as a high resolution display device.

[0002]

2. Description of the Related Art An active matrix address type display device is used as a matrix image display device capable of displaying high resolution and high contrast. At present, active matrix display devices widely used are of a type in which switching elements (for example, thin film transistors) provided in each picture element region are driven in a line-sequential manner.

[0003] In the specification of the present application, an area of the display device corresponding to a "picture element" which is a minimum unit of display is called a "picture element area". In a color display device, R, G, B
Each "dot" corresponds to one "pixel".

However, an active matrix type display device requires a large number of switching elements to be provided on a substrate, and thus has a problem that the yield is deteriorated particularly when a large-area display device is manufactured.

In order to solve this problem, Buzak et al.
Japanese Patent Application Laid-Open No. 1-217396 proposes a plasma addressed display device using a discharge plasma switch instead of the above switching element.

Referring to FIG. 14, a plasma addressed liquid crystal display device (hereinafter referred to as "PALC") for driving a liquid crystal cell using a discharge plasma switch will be briefly described.

FIG. 14 is a partially cutaway view of the PALC 200. The PALC 200 has a structure in which a liquid crystal cell 201 and a plasma cell 202 are stacked with a common dielectric layer 203 interposed therebetween. The plasma cell 202 includes an insulating substrate 2 on which a plurality of stripe-shaped grooves 205 parallel to each other are formed.
Each of the grooves 205 and the dielectric layer 203 has a sealed plasma channel (also referred to as a “discharge channel”). Let the plasma channel be denoted by the same reference numeral 205 as the groove. Plasma channel 2
A gas that can be ionized by electric discharge is enclosed in 05. A pair of plasma electrodes 206 is provided at the bottom of the groove 205.
And 207 are provided. Using one of the pair of electrodes 206 and 207 as an anode (A) and the other as a cathode (K), a voltage is applied to the gas sealed in the plasma channel 205 to ionize the gas to generate discharge plasma.

On the other hand, the liquid crystal cell 201 is
And a liquid crystal layer 209 provided between the first dielectric layer 203 and the dielectric layer 203. On a surface of the upper substrate 208 facing the liquid crystal layer 209, a plurality of transparent electrodes 210 in a stripe shape parallel to each other are provided.
Is provided. The striped transparent electrode 210 is
Stripe-shaped groove 205 provided on lower substrate 204
(That is, the plasma channels), and each intersection defines an individual pixel region arranged in a matrix.

In this PALC 200, for example,
The plasma channel 205 is a unit for row scanning, and the transparent electrode 210 is a unit for column driving. Each plasma channel 205 is sequentially activated by selective plasma discharge, and line-sequential scanning is performed for each row. In sync with this,
A drive signal is applied to each of the transparent electrodes 210 as a column drive unit to drive the liquid crystal layer 209 for each pixel region. When the plasma channel 205 is activated by the plasma discharge, the inside of the plasma channel 205 becomes almost uniformly at the anode potential, and one end of each pixel region is connected to the anode potential via the dielectric layer 203. Thus, the plasma channel 205 forms a so-called plasma switch. A drive signal is applied to the other end of each picture element region in synchronization with the time when the switch is turned on, and the liquid crystal layer 209 is driven.
The applied drive signal is held even after the plasma switch is turned off, and so-called sample hold is performed.

[0010]

However, the above-described plasma addressed display device has various problems described below.

The dielectric layer 203 not only seals the liquid crystal layer 209 and the plasma channel 205, but also
It also functions as an insulation barrier between the plasma channel 09 and the plasma channel 205. Such a dielectric layer 203 is a dielectric sheet such as a thin glass plate, and functions as a dielectric of a capacitor interposed between the pixel region and the plasma switch. The thickness of the liquid crystal layer 209 is considerably smaller than the thickness of the dielectric layer 203, for example, about 6 μm (about 12% of the thinnest dielectric layer (about 50 μm for practical use)). The drive voltage applied to the pixel region is distributed (capacity division) to the liquid crystal layer 209 and the plasma channel 205 according to the thickness and the dielectric constant.
The effective component directly contributing to 09 is about 1/10 of the drive voltage. In other words, a drive voltage that is about 10 times the effective voltage to be applied to the liquid crystal layer 209 is required.

In order to apply a sufficient electric field to the liquid crystal layer 209, the thickness of the dielectric layer 203 is preferably as small as possible. However, the dielectric layer (typically thin glass) 20
When the thickness of No. 3 is reduced, there is a problem that the operability is reduced and the yield of the manufacturing process is reduced.

As described above, in the conventional plasma addressed display device, since a relatively high driving voltage is used, the potential difference between the adjacent transparent electrodes 210 in different display states becomes large, and as a result, the adjacent transparent electrodes 210 become large. Transparent electrode 21
There is a problem that an electric field leaks (leakage of a horizontal electric field) occurs during zero, and display quality is degraded due to so-called crosstalk.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and has as its object to provide a plasma addressed display device in which a decrease in display quality due to a crosstalk phenomenon is suppressed or prevented.

[0015]

According to the present invention, there is provided a plasma addressed display device comprising: a first substrate; a dielectric layer provided so as to face the first substrate; A display medium layer provided therebetween, a second substrate provided so as to face the display medium layer via the dielectric layer, and a second substrate provided between the dielectric layer and the second substrate. ,
A plurality of plasma channels, each containing an ionizable gas, extending in a first direction, comprising a plurality of rows along the first substrate and a plurality of columns along a second direction different from the first direction. A plasma address display device having a plurality of picture element regions arranged in a matrix,
The first substrate has at least one counter electrode on the display medium layer side, and the second substrate is provided in each of the plurality of plasma channels.
A plurality of scan electrodes extending in the direction,
A plurality of signal electrodes extending in a direction, the plurality of plasma channels are provided corresponding to the plurality of rows, and the plurality of plasma channels are selectively discharged by a scan voltage selectively applied to the plurality of scan electrodes. And the display medium layers of the plurality of picture element regions are addressed on a row-by-row basis by the scanning voltage, and via the plasma channel in which a plasma discharge is selectively generated among the plurality of plasma channels. The display state changes depending on the applied voltage between the plurality of signal electrodes and the at least one counter electrode, thereby achieving the above object.

It is preferable that the at least one counter electrode is a single counter electrode provided commonly to the plurality of picture element regions. The at least one counter electrode may be a plurality of striped electrodes provided corresponding to the plurality of columns, and a common counter voltage may be applied to the plurality of striped electrodes.

It is preferable that the plurality of scanning electrodes and the plurality of signal electrodes function as plasma electrodes for the plasma discharge.

It is preferable that the plurality of signal electrodes have a branch portion extending in the first direction in a region corresponding to the plurality of picture element regions.

After selectively applying the scan voltage to the plurality of scan electrodes, the plurality of picture element regions belong to a row addressed by a plasma channel in which plasma discharge is selectively generated by the scan voltage. Preferably, a signal voltage corresponding to a picture element region is applied to the plurality of signal electrodes.

Preferably, after selectively applying the scan voltage to the plurality of scan electrodes, the scan electrode to which the scan voltage is applied is brought into a high impedance state.

It is preferable that a counter voltage synchronized with a signal voltage applied to the plurality of signal electrodes is applied to the at least one counter electrode.

Each of the plurality of scanning electrodes and the plurality of signal electrodes has a first electrode layer and a second electrode layer covering the first electrode layer, and the second electrode layer is higher than the first electrode layer. It is preferable to be formed from a material having a small work function.

[0023] It is preferable that the plasma density in a plasma channel in which a plasma discharge is selectively generated among the plurality of plasma channels is lower in a region between the plurality of columns than in another region.

It is preferable that each of the plurality of plasma channels has a partition in each of the regions between the plurality of rows.

Hereinafter, the operation of the present invention will be described.

A plasma address display device according to the present invention is a display device having a plurality of picture element regions arranged in a matrix, comprising: a display medium layer provided between a first substrate and a dielectric layer; A second substrate provided to face the display medium layer via the dielectric layer; and a plasma channel extending in the row direction between the dielectric layer and the second substrate.
The first substrate has a counter electrode on the display medium layer side. The second substrate has a scanning electrode extending in a row direction parallel to the plasma channel and a signal electrode extending in a column direction different from the scanning electrode. The plasma channel selectively generates a plasma discharge by a scanning voltage applied to the scanning electrode,
The display media layer is addressed row by row. A voltage between the signal electrode and the counter electrode is applied to the display medium layer via the plasma channel in which the plasma discharge has occurred. The display medium layer changes the display state according to this voltage. That is,
In the plasma addressed display device of the present invention, both the scan electrodes for addressing the display medium layer in units of rows and the signal electrodes extending in the column direction for applying a signal voltage to the display medium layer are formed on the second substrate. It is provided in. Therefore, it is not necessary to apply different voltages for each column to the counter electrode provided on the display medium layer side of the first substrate, so that occurrence of crosstalk due to the lateral electric field is prevented.

The signal voltage applied to the signal electrode provided on the second substrate is applied to the display medium layer via the plasma channel in the discharge state and the dielectric layer in contact with the plasma channel. Therefore, unlike the transparent electrode (column electrode) in the conventional plasma address display device, the signal electrode does not need to have a width corresponding to one column of the picture element region. That is, the signal electrode does not need to be formed using a transparent conductive material, and can be formed using a material (typically, a metal material) having higher conductivity than the transparent conductive material. Since the signal electrodes can be formed using a material with high conductivity, the deterioration of display quality due to a voltage drop or signal delay due to an increase in the electrical resistance of the electrodes due to the large screen and high definition of the display device is suppressed. Can be prevented.

The counter electrode may be a single counter electrode (common electrode) provided in common for a plurality of picture element regions (over the entire picture element region), or a stripe provided for each column. It may be a shaped electrode.

The formation of a single counter electrode (consisting of a single continuous conductive layer) simplifies the structure and manufacturing process of the plasma addressed display device, thereby improving the manufacturing yield. . The counter electrode formed over the entire display region can be formed by using a mask deposition method (for example, a mask sputtering method). With the use of the mask deposition method, there is no need to use a photolithography process, so that the counter substrate (the substrate on which the counter electrode is formed) is not exposed to, for example, a strongly alkaline stripping solution used in a resist stripping step. .
Therefore, a protective layer (also called a passivation layer) provided for protecting a color filter layer formed on an opposite substrate from a stripping liquid in a color display device can be omitted. As described above, by using a single electrode as the counter electrode, the structure and manufacturing process of the plasma addressed display device can be simplified,
The yield can be improved or the product cost can be reduced.

Further, since the single counter electrode has a larger area than a conventional transparent electrode (column electrode), a sufficiently low resistance can be realized with a relatively thin transparent conductive layer. Therefore, it is not necessary to increase the thickness of the transparent conductive layer at the expense of transmittance in order to reduce the resistance of the counter electrode.

Since the signal electrode is provided on the second substrate together with the scan electrode, when the scan electrode is used as a cathode (or anode) for plasma discharge, the signal electrode is used as an anode (or cathode) for plasma discharge.
Can be used as When such a configuration is adopted, it is not necessary to separately provide an anode (or a cathode), so that the structure and the manufacturing process of the display device can be simplified.

In a configuration in which the signal electrode is used as a plasma electrode (anode or cathode) for plasma discharge, a plasma discharge is generated in the vicinity of the intersection between the scanning electrode and the signal electrode (region where the electric field strength is high). Since the plasma discharge depends on the distance between the cathode and the anode, merely intersecting the linear scanning electrode and the signal electrode causes unevenness (instability) of the plasma discharge and lowers the display quality. Sometimes. If a configuration is employed in which the signal electrode has a branch portion extending in parallel with the scanning electrode in a region corresponding to the pixel region, a portion where the cathode and the anode are arranged in parallel is formed, so that the uniformity of plasma discharge generation Performance (stability) is enhanced, and display quality can be improved.

After a scan voltage is selectively applied to the scan electrode, a signal voltage corresponding to a picture element region belonging to a row addressed by a plasma channel in which plasma discharge is selectively generated by the scan voltage is applied to the signal electrode. As a result, the activated plasma channels have the potential of the signal electrode corresponding to each pixel region for each column. Therefore, the display medium layer in each picture element region can be set to a display state corresponding to the signal voltage.

When a signal voltage is applied to the signal electrode, an amount of charge corresponding to the voltage between the signal electrode and the counter electrode is induced and accumulated on the lower surface (the second substrate side) of the dielectric layer. After selectively applying a scan voltage to the scan electrode, the scan electrode to which the scan voltage is applied is brought into a high impedance state, so that these charges do not flow to the scan electrode functioning as a cathode, and are opposed to the signal electrode. A decrease in voltage between the electrode and the electrode (a decrease in voltage holding ratio) is prevented.

By applying a counter voltage synchronized with the signal voltage applied to the signal electrode to the counter electrode, the polarity of the voltage between the signal electrode and the counter electrode can be inverted. As a result, it is possible to suppress or prevent burning and afterimages. The driving polarity of the signal electrode can be fixed to a single value, and the withstand voltage of the signal circuit for controlling the signal voltage can be reduced.

The scanning electrode and the signal electrode have a first electrode layer and a second electrode layer covering the first electrode layer, and the second electrode layer has a higher electric resistance than the first electrode layer. The display quality can be further improved. The first electrode layer having a lower electric resistance than the second electrode layer suppresses a voltage drop or a signal delay in the extending direction (row or column direction) of the electrode due to the resistance of the electrode. Further, the second electrode layer having an electric resistance higher than that of the first electrode layer participates in the plasma discharge, and when the plasma discharge is locally generated, the larger the voltage drop is, the more the plasma discharge is suppressed. A uniform plasma discharge can be obtained.

In the plasma addressed display device, crosstalk (referred to as "data diffusion crosstalk: DDC") occurs due to a cause different from the crosstalk due to the lateral electric field described above. DDC occurs when charges induced and accumulated on the lower surface of the dielectric layer in the plasma channel in accordance with the voltage applied to the pixel region, diffuse in the plasma channel.

Therefore, by adopting a configuration in which the plasma density in the plasma channel in which the plasma discharge has occurred is lower in the region between the plurality of columns than in the other regions, D
DC can be suppressed and prevented. For example, by forming a partition in each plasma channel in a region between a plurality of columns, a plasma density in a region between a plurality of columns can be reduced.

[0039]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a plasma addressed display device according to an embodiment of the present invention will be described with reference to the drawings. The present invention is not limited by the following embodiments.

(Embodiment 1) FIG. 1 shows a plasma addressed liquid crystal display (PALC) 1 according to Embodiment 1 of the present invention.
00 is shown. The PALC 100 is a liquid crystal display device using a liquid crystal layer as a display medium layer, but the present invention can be widely applied to various plasma address display devices regardless of the display mode and the type of display medium.

The PALC 100 includes a first substrate (for example, a glass substrate) 103, a dielectric layer (for example, thin glass) 107 provided so as to face the first substrate 103, a first substrate 103 and a dielectric layer 107. A display cell 101 including a liquid crystal layer 105 provided between the display cell 101 and a dielectric layer 107.
A second layer provided to face the liquid crystal layer 105 with the
A substrate (eg, a glass substrate) 116 and a dielectric layer 105
And a second substrate 116, the plasma cell 102 including a plurality of plasma channels 112 each including an ionizable gas and extending in the row direction. The PALC 100 has a plurality of picture element regions 117 arranged in a matrix along a row direction which is a direction in which the plasma channel 112 extends and a column direction different from (typically orthogonal to) the row direction. are doing.

The first substrate 103 has a counter electrode 104 on the liquid crystal layer 105 side. The counter electrode 104 is a single transparent conductive film (for example, an ITO (indium tin oxide) film)
Is a flat solid electrode formed from, for example, a mask deposition method. The liquid crystal layer 105 may be a liquid crystal layer for various electro-optical operation modes. If necessary, alignment films (not shown) are provided on both sides of the liquid crystal layer 105 (the surfaces of the first substrate 103 and the dielectric layer 107 that are in contact with the liquid crystal layer 105). The thickness of the liquid crystal layer 105 is set to a predetermined thickness (for example, 6 μm) by the spacer.

The second substrate 116 has a plasma channel 11
2 has a scanning electrode (cathode) 109 extending in the row direction and a signal electrode (anode) 108 extending in the column direction. The scanning electrode 109 and the signal electrode 108 are insulated from each other by an insulating layer (not shown). The signal electrode 108 and the scanning signal 109 are formed of a metal material, and have a desired thickness (for example, about 30 to about 60 μm).
It is preferable to have In the following embodiments, a structure in which the signal electrode 108 also functions as an anode will be described. However, as in the related art, an anode provided in parallel with the scanning electrode (cathode) 109 may be separately provided. Further, the scan electrode 109 can function as an anode and the signal electrode 108 can function as a cathode.

One picture element region 117 is defined for each intersection between the scanning electrode 109 and the signal electrode 108. The two-dimensional spread of the picture element region 117 is defined by a region where plasma is substantially generated, as described later. The width of the pixel region 117 in the column direction is substantially defined by the interval between the partition walls 110, and the width in the row direction is the width of the plasma in the row direction (the positional relationship between the signal electrode (anode) 108 and the scanning electrode (cathode) 109). Etc.).

The plasma channel 112 is provided on the second substrate 11
6 and the dielectric layer 107 are separated from each other by stripe-shaped barrier ribs 110 formed therebetween. Partition wall 110
Are provided substantially parallel to the scanning electrodes 109, and the scanning electrodes 109 are arranged between the adjacent partition walls 110. The plasma channel 112 includes the second substrate 116, the dielectric layer 1
An ionizable gas (for example, helium, neon, and argon, or a mixed gas thereof) is sealed in a space surrounded by 07 and the partition 110. The plasma channel 112 selectively generates a plasma discharge by a scanning voltage selectively applied to the scanning electrode 109, and addresses the liquid crystal layer 105 in the pixel region in units of rows.
A voltage between the counter electrode 104 and the signal electrode 108 is applied to the liquid crystal layer 105 (and the dielectric layer 107) of the picture element region 117 addressed by the selective plasma discharge,
The orientation of the liquid crystal layer 105 changes according to the voltage, and display is performed.

The PALC 100 according to the present invention is not limited to a transmissive display device, but may be a reflective display device. In the case of a reflective display device, one of the first substrate 104 and the second substrate 116 may be a transparent substrate (for example, a glass substrate). The arrangement when the PALC 100 is actually used is not limited to the arrangement shown in FIG. 1 (the first substrate 104 is on top), and may be reversed.

Next, the structure and manufacturing method of the plasma cell 102 will be described with reference to FIGS. As described above, the liquid crystal cell 101 has substantially the same structure as the conventional PALC except that the counter electrode 104 can be a single electrode commonly used for all the pixel regions 117. Detailed description is omitted.

FIG. 2 is a top view of the plasma cell 102, and FIGS. 3A and 3B correspond to sectional views taken along lines 3a-3a 'and 3b-3b' in FIG.

As shown in FIG. 2, the partition 110 is formed in a stripe shape. Signal electrode 108 and scanning electrode 1
An end portion 09 (not shown) extends from the display region (consisting of picture element regions arranged in a matrix) toward the peripheral portion, and is used for electrical connection with the outside (such as a drive circuit). Can be

On the main surface of the second substrate (for example, a glass substrate) 116, a conductive material is deposited with a predetermined thickness (for example, about 30 to about 60 μm) to form a conductive film, and the conductive film is patterned. Thus, the signal electrode 108 and the scan electrode 1
09 is formed. For example, when patterning is performed using a sandblast method, the following procedure can be adopted.

First, the conductive film is formed using any appropriate material (eg, nickel, tungsten, copper, aluminum) by any appropriate method (eg, vacuum deposition, sputtering, or screen printing). obtain. Next, a photoresist is coated on the conductive film, and the photoresist is patterned through a mask having a predetermined pattern. By spraying abrasive particles on the exposed portions, the conductive film is mechanically etched to a predetermined depth to form the scan electrodes 109.

Next, an insulating layer 111 is provided at the intersection of the signal electrode 108 and the scanning electrode 109. For example, when forming using a screen printing method, the following procedures can be adopted. First, the insulating layer is selectively patterned in a predetermined area by a screen printing method using any appropriate material (for example, a glass paste having a low melting point). Then, the insulating layer 111 is obtained by sintering the glass paste.

After forming the insulating layer 111, the signal electrode 108 can be formed in the same manner using the same material as that of the scanning electrode 109. In addition, the extraction part (extended part for external connection) of the signal electrode 108 and the scanning electrode 109 is
It can be patterned by another step. For example, the extraction portions of the signal electrode 108 and the scanning electrode 109 may be patterned by mechanical etching using abrasive particles, or may be patterned by chemical etching using any appropriate solution (for example, strong acid). May be used.

The partition 110 can be formed by the same method using the same material as the insulating layer 111. For example, a desired thickness is obtained by repeating the above-described step of forming the insulating layer 111 a plurality of times.

On the other hand, as shown in FIG.
A frit seal 118 is printed on the periphery of the main surface of No. 6 so as to surround the display area. Preferably, at least one connection groove 1 is provided inside the frit seal 118.
20 are formed. The connecting groove 120 is formed in the second substrate 1
It is provided so that the pattern of the stripe-shaped partition wall 110 formed on 16 is interrupted. The second substrate 116 having such a configuration is attached to the dielectric layer 107 with a frit seal 118, and is subjected to heat and pressure treatments to hermetically seal the second substrate 116 and the dielectric layer 107.

Communication groove 120 formed in second substrate 116
Is a stripe-shaped plasma channel (discharge region) 11
Cross 2 After the second substrate 116 and the dielectric layer 107 are hermetically sealed, a predetermined ionizable gas (plasma gas) is supplied to each plasma channel 112 through the communication groove 120.
To be introduced. At the end of the gas introduction, the vent 119
Is sealed. Thus, the plasma cell 102 is manufactured.

In the liquid crystal cell 101, for example, the first substrate 103 is bonded to the dielectric layer 107 of the plasma cell 102 via a spacer at a predetermined gap, and the liquid crystal layer 1 is
The liquid crystal cell 101 can be manufactured by sealing and filling the liquid crystal material constituting the liquid crystal material 05. If necessary, the first substrate 103 may be provided with a color filter layer or a black matrix. Thus, the PALC 100 including the liquid crystal cell 101 and the plasma cell 102 can be manufactured.

In the PALC 100 of the present embodiment,
Scan electrode 1 for addressing liquid crystal layer 105 in units of rows
09 and the signal electrode 108 extending in the column direction for applying a signal voltage to the liquid crystal layer 105 are both connected to the second substrate 116.
It is provided in. Therefore, it is not necessary to apply different voltages to the opposing electrode 104 of the first substrate 103 for each column, so that the occurrence of crosstalk due to the lateral electric field is prevented.

Since the counter electrode 104 is formed from a single continuous conductive layer, it is possible to improve the production yield of the PALC 100. Furthermore, a single counter electrode 1
04 has a larger area than conventional transparent electrodes (column electrodes), so that a relatively thin transparent conductive layer can realize sufficiently low resistance. Therefore, in order to reduce the resistance of the counter electrode 104,
There is no need to thicken the transparent conductive layer at the expense of transmittance,
Bright display is realized.

Since the signal electrode 108 is provided on the second substrate 116 together with the scanning electrode 109, the scanning electrode 109 can be used as a cathode and the signal electrode 108 can be used as an anode. There is no need, and the structure and manufacturing process of the display device can be simplified.

(Embodiment 2) A PALC according to another embodiment of the present invention will be described. In the following embodiments, for simplicity, components having substantially the same functions as those of the PALC 100 of the first embodiment are denoted by the same reference numerals, and description thereof will be omitted.

The PALC of the second embodiment is a
Has a branching portion 108 ′ for each pixel region 117 and is different from the PALC 100 of the first embodiment. FIG.
The structure of the PALC plasma cell of Embodiment 2 (corresponding to the plasma cell 102 of FIG. 1) will be described with reference to FIG. 5 and FIG.

FIG. 4 is a schematic plan view of the second substrate 116, and FIGS. 5 (a), 5 (b) and 5 (c) show 5a-5a ', 5b-5b' and 5c- It is a schematic cross section along line 5c '.

In the picture element region defined corresponding to the intersection of the signal electrode 108 and the scanning electrode 109, the signal electrode 10
8 has a branch part 108 '. Branch 108 '
Are arranged substantially parallel to the scanning electrodes 109. That is,
The distance between the branching portion 108 'and the scanning electrode 109 is substantially constant in each picture element region 117. Branch 108 '
Are formed integrally with the scanning electrode 109.

In the PALC 100 of the first embodiment, a linear (for example, about 100 μm wide) scan electrode (cathode) 1
Since a plasma discharge is generated near the intersection of the signal electrode 09 and the signal electrode (anode) 108 (region where the electric field strength is high), the generation of the plasma discharge becomes non-uniform (unstable) and the display quality may deteriorate. . On the other hand, Embodiment 2
The signal electrode 108 has a branching portion 108 ′ extending in parallel with the scanning electrode 109 in a region corresponding to the pixel region 117.
The uniformity of plasma discharge generation (stability)
And display quality can be improved. In order to increase the uniformity of the plasma discharge, it is preferable that the branch portion 108 ′ is provided so as to face the scan electrode 109 in parallel over the entire pixel region 117.

(Embodiment 3) A PALC of still another embodiment according to the present invention will be described. P according to Embodiment 3
The ALC differs from the PALC 100 of the first embodiment in that the ALC has a partition wall 110a that substantially divides the plasma channel 112 into regions corresponding to the pixel regions 117.

Referring to FIG. 6, a PAL according to the third embodiment will be described.
The structure of the C plasma cell will be described. FIG. 6 shows the first embodiment.
2 corresponds to FIG.

The partition 110 a extends in the column direction, and a plasma channel 112 (see FIG. 1) formed in a gap between the dielectric layer 107 and the second substrate 116 is formed in a region corresponding to the pixel region 117. Is substantially divided. The distance between the adjacent partitions 110a is appropriately changed according to the size of the picture area. The partition 110a can be formed over the second substrate 116 by a similar method using a material similar to that of the partition 110. However, it is only necessary that the region where the plasma discharge occurs can be practically limited, and it is not necessary to join or contact the dielectric layer 107.

The width of the plasma discharge in the plasma channel 112 in the row direction can be restricted by the partition wall 110a. As a result, the range in which the lines of electric force applied by the voltage between the counter electrode 104 and the signal electrode 108 applied to the liquid crystal layer 105 and the dielectric layer 107 via the plasma channel 112 are limited, and Along with the adjacent pixel area 117 is prevented. Therefore, DD
A high-quality display in which the generation of C is suppressed / prevented is realized.

The plasma channel 112 is connected to the picture element region 117.
The configuration in which the partition 110a is divided into regions corresponding to the above can be applied to other PALCs. For example, when applied to the PALC of Embodiment 2, the partition 110a can be easily formed by partially increasing the height of the insulating layer 111 for insulating and protecting the signal electrode 108,
DDC can be suppressed and prevented.

(Embodiment 4) A PALC of still another embodiment according to the present invention will be described. P according to Embodiment 4
The ALC differs from the PALC 100 of the first embodiment in that the signal electrode 108 and the scanning electrode 109 are each formed from a plurality of conductive layers.

The structure of the signal electrode 108 and the scanning electrode 109 of the PALC according to the fourth embodiment will be described with reference to FIGS. 7 (a), 7 (b) and 7 (c). Here, the signal electrode 108 and the scan electrode 1 of the PALC 100 of the first embodiment are described.
09 is formed using two conductive layers. 7A corresponds to a sectional view taken along line 3a-3a 'in FIG. 2, and FIGS. 7B and 7C correspond to sectional views taken along line 3b-3b' in FIG.

Each signal electrode 108 and 109
Are the lower conductive layers (first electrode layers) 108b and 109b
And an upper conductive layer (second electrode layer) 108 formed thereon
a and 109a. The upper conductive layers 108a and 109a are formed of the plasma channel 112 of the plurality of conductive layers forming the respective electrodes 108 and 109.
And the lower conductive layers 108b and 1
09b indicates a conductive layer other than the upper conductive layers 108a and 109a. Here, a two-layer structure is illustrated, but a structure having a plurality of lower conductive layers 108b and 109b may be employed.

The material forming lower conductive layers 108b and 109b is a low-resistance material (eg, copper or aluminum)
Is preferred. When the center of the electrodes 108 and 109 (the lower conductive layers 108b and 109b) has a low resistance value,
Voltage drop in the direction in which the electrodes extend (row or column direction) can be suppressed.

On the other hand, as the material forming the upper conductive layers 108a and 109a directly involved in the plasma discharge, a material having a small work function is suitable. In general, when the work function is small, the γ coefficient (the number of electrons emitted when one plasma ion collides) is large, and the discharge voltage can be reduced. As such typical materials,
Borides such as lanthanum hexaboride, gadolinium hexaboride, and yttrium tetraboride. Since these materials have characteristics of a high melting point and a low sputtering rate, they are well known as materials suitable for discharge electrode materials.

Next, a method for forming the above-described two-layer structure electrode will be described.

First, the lower conductive layer 1 of the scan electrode 108 is formed on the second substrate 116 to a desired thickness by, for example, a vacuum evaporation method.
08b is made of a low-resistance material (for example, aluminum)
It is formed using. Next, a photoresist is coated on the low-resistance conductive film, and the photoresist is patterned through a mask having a predetermined pattern. The lower conductive layer 109b of the scan electrode 109 is formed by spraying abrasive particles onto the exposed low-resistance conductive film.

Next, the insulating layer 111 is formed at a predetermined position by, for example, a screen printing method.
The lower conductive layer 108b of the signal electrode 108 is formed in the same manner as the lower conductive layer 109b.

Next, a high-resistance material is laminated on the lower conductive layers 109b and 108b by, for example, an electrodeposition method, baked, and then patterned to form the upper conductive layers 108a and 108a.
By forming 09a, a signal electrode 108 and a scanning electrode 109 having the cross-sectional structure shown in FIG. 7B are obtained. When this process is adopted, the upper conductive layer 10
There is an advantage that the steps for forming 8a and 109a can be shared. Scan electrode 109 in a portion covered with insulating layer 111
Is formed only with the lower conductive layer 109b, but the upper conductive layer 109a is effective when exposed to the plasma channel 112, and is not required below the insulating layer 111.

Alternatively, in the above forming process,
After forming the lower conductive layer 109b of the scan electrode 109,
After forming the upper conductive layer 109a of the scan electrode 109 using a high-resistance material by, for example, a sputtering method, the signal electrode 108 having the cross-sectional structure shown in FIG. And scanning electrode 1
09 is obtained.

It is needless to say that the configuration in which the signal electrode 108 and the scanning electrode 109, which also function as plasma discharge electrodes, have a multilayer structure can be applied not only to the PALC of the first embodiment but also to the PALCs of the second and third embodiments.

Next, the operation of the PALC according to the present invention will be described.

FIGS. 8, 9A, 9B, 9C and 1
The operation of the PALC in which the signal electrode 108 also functions as the anode will be described with reference to FIG. The operation (driving method) of the PALC in which the anode is formed separately from the signal electrode 108 can be easily understood by those skilled in the art from the following description, and the description is omitted.

FIG. 8 is a schematic block diagram of a drive circuit used as a drive circuit of the PALC according to the first to fourth embodiments. 9A, 9B, and 9C are schematic diagrams illustrating the operation of the PALC of the above embodiment. FIG.
5 is a timing chart of each signal for driving the PALC of the embodiment.

As shown in FIG. 8, the driving circuit has a signal circuit 131, a scanning circuit 132, and a control circuit 133. A plurality of signal electrodes D1 to Dm are connected to the signal circuit 131 via buffers. Scanning circuit 132
Are connected to a plurality of scanning electrodes (cathodes) K1 to Kn via buffers. Note that the signal electrodes D1 to Dm correspond to those indicated by reference numeral 108 in the previous drawings, and correspond to the scanning electrode (cathode) K1.
To Kn correspond to those indicated by reference numeral 109. The portion where the signal electrode 108 and the scanning electrode 109 intersect (the portion that generates plasma discharge) is the plasma switch 1
Functions as 14.

Here, the opposing electrode 104 is grounded. The control circuit 133 includes the signal circuit 131 and the scanning circuit 1.
32 are controlled synchronously with each other. The scanning electrodes 109 connected to the scanning circuit 132 are scanned line-sequentially, and a plasma discharge voltage is applied between the scanning electrodes 109 and the corresponding signal electrodes 108 to generate a plasma discharge.

On the other hand, an analog drive voltage is applied to the signal electrode 108 connected to the signal circuit 131 in synchronization with line-sequential scanning. Each pixel region 117 is defined at the intersection of the signal electrode 108 serving as a column driving unit and the scanning electrode 109 serving as a row scanning unit (see FIG. 1).

9A to 9C schematically show one picture element area. The picture element region 117 has a laminated structure, and includes a first substrate 103, a counter electrode 104, a liquid crystal layer 105, a dielectric layer 107, a signal electrode 108 and a scanning electrode 109,
The substrate 116 is overlaid. The virtual electrode 113
Is a functional representation of electric charge induced and accumulated on the surface of the dielectric layer 107 on the plasma channel 112 side by plasma discharge.

FIGS. 9A to 9C respectively show the period to (or period ') in the timing chart of FIG.
1 to 3) schematically show the operating state of the PALC.

The state in the period of FIG. 10 (FIG. 9A): all the signal electrodes 108 are set to the ground potential, and the scanning electrode 1 in a certain row is set.
At 09, a scanning signal 132 'is applied. At this time, FIG.
As shown in A, a plasma discharge is generated in the corresponding plasma channel 112, and an ionized gas (plasma) 115 is generated (also referred to as "the plasma channel is activated"). This state corresponds to a state in which the plasma switch 114 is conductive and the virtual electrode 113 is present. On the other hand, in the non-selected rows, the plasma switch 114 is not activated because the plasma channel 112 is not activated.
Is in a non-conductive state.

State of FIG. 10 (FIG. 9B): When a predetermined analog drive voltage 131 ′ is applied to the signal electrode 108 at the time when the plasma switch 114 is turned on, the liquid crystal existing between the counter electrode 104 and the grounded electrode is applied. A drive voltage is applied to the layer 105 and the dielectric layer 107. That is,
The liquid crystal layer 105 in each picture element region forms a sampling capacitor, and the corresponding plasma switch 114 functions as a sampling switch. At this time, the dielectric layer 107 functions as a part of the sampling capacitor. According to the applied drive voltage, as shown in FIG.
The orientation state of 05 changes.

State in FIG. 10 (FIG. 9C): When application of the plasma voltage to scanning electrode 109 and signal electrode 108 is completed, plasma 115 is extinguished, and the plasma switch is turned off. The charge stored in the sampling capacitor is retained even after the plasma switch is turned off, so that a so-called sampling hold is performed. The liquid crystal layer 105 maintains the alignment state shown in FIG. 9B.

The image display operation will be described with reference to FIG. For simplicity, FIG. 10 shows n + 1 of FIG.
The operation of only the plasma switch 114 (one picture element region 117 shown in FIG. 1) in the row m + 1 will be described.

A case will be described in which the scanning of the n-th row (period to) is completed, and then the scanning of the (n + 1) -th row is started.

First, all the anode / signal electrodes are set to the ground level, and during that period, a scanning signal is applied to the (n + 1) th row of scanning electrodes 109 (period ′ in FIG. 10). And n +
The plasma channel in the first row causes a plasma discharge to turn on the plasma switch. While the plasma switch on the (n + 1) th row is in the conductive state (period 'in FIG. 10),
An analog drive voltage is applied to the signal electrode 108 in the (m + 1) th column (actually, an analog signal voltage corresponding to each of all the columns is applied at this time). The signal is written. Thereafter, even when the plasma switch is turned off (period 'in FIG. 10), the written image signal (voltage corresponding to the image signal) is composed of the counter electrode / liquid crystal layer / dielectric layer / virtual electrode. Held by the capacitor.

By repeating this operation for each scanning electrode (plasma channel), the PALC is driven line-sequentially.

Referring to FIG. 11, a PA according to the present invention will be described.
Another operation example of the LC will be described. For comparison, reference is also made to FIG. 9B used in the above description of the operation.

In FIG. 9B, an analog drive signal is applied to the signal electrode 108 while the plasma switch is in a conductive state (a state in which the ionized gas 115 is generated). However, the applied drive voltage (corresponding to the image signal) is applied to the scan electrode (cathode) 10 via the plasma switch.
9, the driving voltage applied to the liquid crystal layer 105 and the dielectric layer 107 decreases (arrow in FIG. 11).

This decrease in drive voltage is caused by the
A plasma discharge is generated by applying a scan voltage to the scan electrode 10 (see the period or ′ in FIGS. 9A and 10), and then, as shown in FIG.
8 can be suppressed by setting it to a high impedance state (FIG. 11 shows a state in which the switch S is disconnected). Such an operation is performed by the scanning circuit 13.
2 can easily be realized.

Next, still another operation example of the PALC according to the present invention will be described with reference to FIGS. The PALC according to the present invention may be driven by the line inversion drive shown in FIG. 12 or by the frame inversion drive (including the field inversion) shown in FIG.

The line inversion drive is executed by controlling each signal as shown in FIG.

After selecting a row by applying a scanning voltage to the scanning electrode 109, the anode / signal electrode 108 is selected.
And applies an opposing voltage to the opposing electrode in synchronization with the analog driving signal applied. The polarity of the counter voltage applied in synchronization with the line-sequential driving executed on a row basis is inverted for each row. As a result, the liquid crystal layer 105 and the dielectric layer 10
The polarity of the voltage written to 7 is inverted for each scanning unit (row).

The frame inversion drive is executed by controlling the respective signals as shown in FIG.

After selecting a row by applying a scanning voltage to the scanning electrode 109, the anode / signal electrode 108 is selected.
And applies an opposing voltage to the opposing electrode in synchronization with the analog driving signal applied. The polarity of the counter voltage applied in synchronization with the line-sequential driving executed on a row-by-row basis is inverted for each frame. As a result, the polarity of the voltage written in the liquid crystal layer 105 and the dielectric layer 107 is inverted for each frame. When one frame is divided into a plurality of fields for scanning, the polarity of the counter voltage may be reversed for each field (field inversion driving).

As described above, by changing the polarity of the voltage applied to the liquid crystal layer 105 (inverting the polarity every certain period), it is possible to suppress the burn-in of the display and the occurrence of an afterimage. In addition, deterioration of the liquid crystal material can be suppressed, and the life can be extended. Further, since the driving polarity of the signal electrode 108 can be fixed to a single value, the withstand voltage of the signal circuit 131 in FIG. 8 can be reduced. For example, a maximum of ±
When a voltage of 60 V is applied, if the voltage of the counter electrode is fixed to 0 V, it is necessary to apply a voltage of ± 60 V, that is, a bipolar voltage, to the signal electrode. When the voltage of the counter electrode is fixed to 60 V, the voltage of the signal electrode is 0 V to 120 V.
May be applied, but a voltage having a large amplitude (120 V) is required. On the other hand, if a driving method in which the voltage of the counter electrode is changed from 0 to 60 V and the voltage of the signal electrode is changed in the range of 60 V to 0 V in synchronization with this, the polarity of the voltage applied to the signal electrode becomes single. And the amplitude only needs to be 60 V, and the withstand voltage of the signal circuit can be reduced.

[0106]

According to the present invention, there is provided a plasma addressed display device in which a reduction in display quality due to a crosstalk phenomenon is suppressed or prevented.

In the plasma addressed display device of the present invention, both the scan electrodes for addressing the display medium layer in units of rows and the signal electrodes extending in the column direction for applying a signal voltage to the display medium layer are provided. It is provided on the second substrate. Therefore, it is not necessary to apply different voltages for each column to the counter electrode provided on the display medium layer side of the first substrate, so that occurrence of crosstalk due to the lateral electric field is prevented.

Further, since the signal electrode can be formed using a material (typically, a metal material) having a higher conductivity than the transparent conductive material, the signal electrode can be formed with a larger screen and higher definition of the display device. It is possible to suppress and prevent a decrease in display quality due to a voltage drop or a signal delay due to an increase in electric resistance.

Further, by forming a single counter electrode (consisting of a single continuous conductive layer), it is possible to simplify the structure and manufacturing process of the plasma addressed display device, thereby improving the yield or improving the product. Cost reduction can be realized.

Further, since the single counter electrode has a larger area than a conventional transparent electrode (column electrode), a sufficiently low resistance can be realized with a relatively thin transparent conductive layer. Therefore, high-quality display is realized without sacrificing the transmittance.

[Brief description of the drawings]

FIG. 1 is a perspective view schematically showing a PALC 100 according to a first embodiment of the present invention.

FIG. 2 is a plasma cell 1 of the PALC 100 according to the first embodiment.
It is a typical top view of No. 02.

3A is a schematic cross-sectional view of the plasma cell 102, taken along line 3a-3a ′ of FIG.

3B is a schematic cross-sectional view of the plasma cell 102, taken along line 3b-3b ′ of FIG.

FIG. 3C is a second substrate 1 used in the plasma cell 102;
16 is a schematic top view of FIG.

FIG. 4 shows a second substrate 1 used for the PALC of the second embodiment.
It is a schematic plan view of No. 16.

FIGS. 5 (a), (b) and (c) respectively show FIG.
FIG. 9 is a schematic cross-sectional view of the second substrate 116 taken along lines 5a-5a ′, 5b-5b ′, and 5c-5c ′ therein.

FIG. 6 is a schematic top view of a plasma cell 102 used for PALC of Embodiment 3.

FIG. 7 shows a signal electrode 1 used for a PALC according to a fourth embodiment.
FIG. 8 is a schematic cross-sectional view of a reference numeral 08 and a scanning electrode 109.

FIG. 8 is a block diagram schematically showing a PALC drive circuit according to an embodiment of the present invention.

FIG. 9A is a schematic diagram illustrating the operation of a PALC according to an embodiment of the present invention (scanning voltage application period).

FIG. 9B is a schematic explanatory view of the operation of the PALC of the embodiment according to the present invention (signal voltage application period).

FIG. 9C is a schematic diagram illustrating the operation of the PALC according to the embodiment of the present invention (signal voltage hold period).

FIG. 10 is a timing chart of signals for driving a PALC according to an embodiment of the present invention.

FIG. 11 is a schematic explanatory view of another operation of the PALC according to the embodiment of the present invention (signal voltage application period).

FIG. 12 is a timing chart of each signal for line inversion driving of the PALC according to the embodiment of the present invention.

FIG. 13 is a timing chart of signals for performing frame inversion driving of the PALC according to the embodiment of the present invention.

FIG. 14 shows a conventional plasma addressed liquid crystal display device 200.
FIG.

[Explanation of symbols]

 100, 200 Plasma address display device 101, 201 Display cell 102, 202 Plasma cell 103, 116, 204, 208 Substrate 104 Counter electrode (common electrode) 105, 209 Liquid crystal layer 107, 203 Dielectric layer (thin glass) 108 Signal electrode (Anode) 108 'Signal electrode branch 109 Scan electrode (cathode) 110, 110a Partition wall 112, 205 Plasma channel 113 Virtual electrode 114 Plasma switch 115 Ionized gas (plasma) 117 Pixel region 118 Frit seal 120 Communication groove 131 Signal circuit 132 Scanning circuit 133 Control circuit

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 2H089 HA36 QA16 TA09 TA12 5C006 AA22 AB05 AC02 BB12 EB04 FA36 FA37 FA51 5C080 AA10 BB05 CC03 CC06 DD10 FF09 JJ02 JJ04 JJ06 KK02 KK43 5C094 AA02 AA04 EA03 DA07 EC04 FB16 GA10

Claims (10)

[Claims] A first substrate; a dielectric layer provided to face the first substrate; a display medium layer provided between the first substrate and the dielectric layer; A second substrate provided so as to face the display medium layer with a body layer interposed therebetween; and a second substrate provided between the dielectric layer and the second substrate, each including a gas that can be ionized, A plurality of picture element regions arranged in a matrix comprising a plurality of rows along the first direction and a plurality of columns along a second direction different from the first direction. A plasma addressed display device, wherein the first substrate has at least one counter electrode on the display medium layer side, and the second substrate is provided in each of the plurality of plasma channels, Extend in the first direction A plurality of scan electrodes, each having a plurality of signal electrodes extending in the second direction, wherein the plurality of plasma channels are provided corresponding to the plurality of rows, and are selectively provided to the plurality of scan electrodes. A plasma discharge is selectively generated by a scanning voltage applied to the plurality of picture element regions, the display medium layers of the plurality of picture element regions are addressed in units of rows by the scanning voltage, and selection of the plurality of plasma channels is performed. A plasma addressed display device, wherein a display state is changed by a voltage applied between the plurality of signal electrodes and the at least one counter electrode, which is applied through a plasma channel in which a plasma discharge is generated. 2. The plasma addressed display device according to claim 1, wherein the at least one counter electrode is a single counter electrode commonly provided in the plurality of picture element regions. 3. The plasma addressed display device according to claim 1, wherein said plurality of scanning electrodes and said plurality of signal electrodes function as plasma electrodes for said plasma discharge. 4. The plasma addressed display device according to claim 3, wherein the plurality of signal electrodes have a branch portion extending in the first direction in a region corresponding to the plurality of picture element regions. 5. The method according to claim 1, wherein the scan voltage is selectively applied to the plurality of scan electrodes, and then a row of the plurality of picture element regions addressed by a plasma channel that selectively generates plasma discharge by the scan voltage. 5. The plasma addressed display device according to claim 1, wherein a signal voltage corresponding to a picture element region belonging to (c) is applied to said plurality of signal electrodes. 6. 6. The plasma addressed display device according to claim 5, wherein after selectively applying the scan voltage to the plurality of scan electrodes, the scan electrode to which the scan voltage is applied is brought into a high impedance state. 7. The plasma addressed display device according to claim 5, wherein a counter voltage synchronized with a signal voltage applied to the plurality of signal electrodes is applied to the at least one counter electrode. 8. The plurality of scanning electrodes and the plurality of signal electrodes have a first electrode layer and a second electrode layer covering the first electrode layer, and the second electrode layer is a first electrode layer. 8. A material having a lower work function than a material having a lower work function.
The plasma addressed display device according to any one of the above. 9. The plasma density in a plasma channel where a plasma discharge is selectively generated among the plurality of plasma channels is lower in a region between the plurality of columns than in another region. The plasma addressed display device according to any one of the above. 10. The plasma addressed display device according to claim 9, wherein each of the plurality of plasma channels has a partition in each of regions between the plurality of columns.