JP3243936B2 - Image display device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image display device for driving an electro-optical material layer using plasma to select an image.

[0002]

2. Description of the Related Art In general, as a means for increasing the resolution and contrast of a display, for example, there is a method of providing an active element such as a transistor for each display pixel and driving it, that is, a so-called active matrix address system. . However, in this case, since it is necessary to provide a large number of semiconductor elements such as thin film transistors, there is a concern about a yield problem particularly when the display is enlarged, and a problem arises that the cost is inevitably increased.

Therefore, as a means for solving this problem,
A method has been proposed in which discharge plasma is used as an active element instead of a semiconductor element such as a MOS transistor or a thin film transistor. Hereinafter, an example of an image display device that drives liquid crystal using discharge plasma will be briefly described.

In this image display device, a liquid crystal layer, which is an electro-optical material layer, and a discharge region where plasma discharge is performed,
It is arranged adjacently via a thin dielectric microsheet made of glass or the like.

In the discharge region, a plurality of first electrodes made of line-shaped conductive paste are arranged at equal intervals on a glass substrate as a first substrate, and the anode and the cathode are alternately arranged. It has been. At one end of each plasma electrode, terminals for applying a voltage to the plasma electrode are alternately provided. Further, partitions made of an insulating paste having a width smaller than that of the plasma electrode are formed on each plasma electrode in parallel with each other, and an ionizable gas is sealed in the discharge region. Then, in each discharge region, the exposed both ends of the plasma electrode due to the formation of the partition function as an anode and a cathode, respectively. The lower part of the microsheet is supported and fixed by the frit provided on the upper end of the partition and the peripheral part of the glass substrate.

On the microsheet, an alignment layer for adjusting the alignment of the liquid crystal and the liquid crystal layer made of a nematic liquid crystal or the like sandwiched between the layers are provided with the periphery thereof supported by a liquid crystal seal. A transparent substrate, which is a second substrate, is disposed above the color filter 1 via a liquid crystal seal and an alignment layer. On the lower part of the transparent substrate, that is, on the surface on the liquid crystal layer side, a plurality of transparent electrodes as second electrodes are formed. These transparent electrodes are orthogonal to the above-mentioned plasma electrodes, and each intersection region with each plasma electrode corresponds to each pixel.

In the above-mentioned image display device, the discharge area where the plasma discharge is performed is sequentially switched and scanned by the above-mentioned terminals, and the signal voltage is applied to the transparent electrode on the liquid crystal layer side in synchronization with the scanning, whereby the signal is applied. The voltage is held in each pixel, and the liquid crystal layer is driven. Therefore, each discharge region corresponds to one scanning line, and the discharge region is divided for each scanning unit.

[0008]

In a large-sized display device such as the above-mentioned image display device, there is a problem that the electric resistance of the plasma electrode is increased. Therefore, an underlayer is provided by printing a paste containing silver having excellent conductivity on a glass substrate serving as the first substrate in a predetermined shape by a screen printing method. As a result, the resistance values of both the plasma electrode and the underlayer decrease, and the underlayer also functions as a part of the electrode portion. At this time, the electric resistance of the electrode portion is half that of the case without the underlayer. It is as follows.

However, when the underlayer is formed by the screen printing method as described above, there is inevitably a limitation in printing accuracy. The limitation is that the width of the underlayer is about 70 μm, and the formation of the underlayer having the width of about this limit lacks certainty in the screen printing method and is poor in mass productivity. If formation failure occurs in the underlayer, the underlayer may be exposed from the plasma electrode when the plasma electrode is formed. As a result, the performance of the image display device is deteriorated without accurate plasma discharge.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems, and has as its object to reduce the resistance of the plasma electrode as the first electrode. It is an object of the present invention to provide an image display device capable of increasing the size of the requested device.

[0011]

SUMMARY OF THE INVENTION The present invention is directed to an image display device utilizing a plasma discharge. That is, in the image display device according to the present invention, a dielectric film is attached to a first substrate having a plurality of strip-shaped first electrodes and a partition, and a second electrode having a second electrode orthogonal to the first substrate is provided. Is an apparatus in which the substrate is disposed on the dielectric film via the electro-optic material layer.

Then, a plurality of band-shaped grooves are formed in the first substrate corresponding to the first electrodes, and the grooves are filled with silver paste, and the first paste made of a conductive paste is formed on each groove. It is characterized by forming electrodes.

At this time, a nickel paste having excellent conductivity is used as the conductive paste. This is because the silver paste has an order of magnitude lower in electrical resistance by one digit or more than the nickel paste, and the electrical resistance of the first electrode can be efficiently reduced.

Further, the firing temperature of the silver paste is 480 ° C.
It is characterized in that a paste is prepared so as to be 580 ° C. After firing the silver paste, a so-called frit seal is performed as a subsequent process.
A temperature of about 470 ° C. is applied to the silver paste. If the firing temperature of the silver paste is lower than 480 ° C., the silver paste may be melted at the time of frit sealing, causing a different reaction and increasing the electric resistance value. In addition, the firing temperature is set to 580 ° C. from the requirement regarding the upper limit of the heat resistance temperature of the glass material as the material of the first substrate.

[0015]

The image display device according to the present invention has a structure in which a plurality of band-shaped grooves are formed on one main surface of the first substrate, and these grooves are filled with silver paste. Therefore, the silver paste surface is easily made parallel to one main surface of the first substrate, and the first electrode made of the conductive paste is accurately formed on each of the grooves filled with the silver paste.
The silver paste has a structure functioning as a silver electrode together with the electrode. That is, since the silver paste is not exposed from the first electrode and the electrode including the first electrode and the silver electrode has a low electric resistance value, the size of the device can be increased.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, specific embodiments of the image display device according to the present invention will be described with reference to the drawings.

The above-mentioned image display device uses a discharge plasma to drive a liquid crystal as an electro-optical material to select an image. In this image display device, as shown in FIG. 1, a liquid crystal layer 11 which is an electro-optic material layer and a discharge region 12 where plasma discharge is performed are formed via a thin dielectric microsheet 13 made of glass or the like. They are arranged adjacent to each other.

In the discharge region 12, a plurality of plasma electrodes 15 as a first electrode made of a nickel paste having excellent line conductivity are formed on a glass substrate 14 as a first substrate at equal intervals. The cathode K and the anode A are alternately arranged. Terminals for applying a voltage to the plasma electrodes 15 are provided alternately at one end of each plasma electrode 15.

Further, a partition 16 made of an insulating paste having a width smaller than that of the plasma electrode 15 is formed on each plasma electrode 15.
Are arranged in the longitudinal direction of the plasma electrode 15, and the discharge region 12
An ionizable gas is sealed therein.

Here, in each discharge region 12, both ends in the width direction of the partition 16 and the narrow plasma electrode 15 are exposed by the formation of the partition 16, and the partition 16 is partitioned by two opposing partitions 16. The defined area is used as a plasma chamber, and the exposed portions 15a and 15
b functions as a pair of electrodes (cathode and anode). Further, the upper end portions of these partition walls 16 and the glass substrate 14
The lower part of the microsheet 13 is supported and fixed by a frit 17 provided on the peripheral edge of the microsheet 13.

In this embodiment, a plasma electrode 1 is placed under each plasma electrode 15 on a glass substrate 14 as a first substrate.
Grooves 23 are formed in parallel with 5, and a silver paste is filled in these grooves 23 to form silver electrodes 24. Here, the surface of the silver electrode 24 in the groove 23 and the surface of the glass substrate 14 are parallel to each other, and the plasma electrode 15 is formed on each groove 23. Here, the silver paste is
It is necessary that the electric resistance value is lower than that of the nickel paste which is the material of the plasma electrode 15, and it is preferable that the electric resistance value is lower by one digit or more.

The liquid crystal layer 11 made of nematic liquid crystal or the like sandwiched between alignment layers 18a and 18b for adjusting the alignment of the liquid crystal is provided on the microsheet 13 with its periphery supported by a liquid crystal seal 19. I have. A transparent substrate 21 as a second substrate is provided above the color filter 20 via the liquid crystal seal 19 and the alignment layer 18b.
Is arranged. The lower part of the transparent substrate 21, that is, the liquid crystal layer 11
A plurality of transparent electrodes 22 as second electrodes are formed on the surface on the side. These transparent electrodes 22 are orthogonal to the respective plasma electrodes 15, and the respective intersection regions with the respective plasma electrodes 15 correspond to the respective pixels 23.

In the above image display device, the discharge area 12 where the plasma discharge is performed is sequentially switched and scanned by the terminals, and the transparent electrode 22 on the liquid crystal layer 21 side is scanned.
By applying a signal voltage in synchronization with this, the signal voltage is held in each pixel, and the liquid crystal layer 11 is driven.
Therefore, each discharge region 12 corresponds to one scan line, and the discharge region is divided for each scan unit.

As described above, in the above image display device, a plurality of band-shaped grooves 23 are formed on one main surface of the glass substrate 14 as the first substrate, and these grooves 23 are filled with silver paste. Having a structure of Therefore, the silver paste surface is easily made parallel to one main surface of the glass substrate 14, and the plasma electrode 15, which is the first electrode made of the nickel paste, is accurately formed on each groove 23 filled with the silver paste. The silver paste is configured to function as the silver electrode 24 together with the plasma electrode 15. That is, since the electrodes composed of the plasma electrodes 15 and the silver electrodes 24 have a low electric resistance without exposing the silver paste, the size of the apparatus can be increased.

Here, in order to manufacture the image display device, first, as shown in FIG. 2, grooves 23 are formed on the glass substrate 14 in parallel with each other. As a method of forming this,
First, a resist is applied to the surface of the glass substrate 14 using a photolithography technique to form a resist layer. Next, after pre-baking, applying a predetermined mask, and exposing, post-baking is performed, developed, and etched into a predetermined groove shape. Then, the groove 23 is completed by removing the resist layer.

Thereafter, as shown in FIG.
3 is filled with a silver paste to form a silver electrode 24 so that the surface of the silver electrode 24 and the surface of the glass substrate 14 are parallel to each other. Next, as shown in FIG. 4, a nickel paste is printed on each of the grooves 23 by using a screen having a predetermined opening by a screen printing method, and a line-shaped plasma electrode 15 having a predetermined width is formed by printing at equal intervals. And dry.

Then, as shown in FIG. 5, an insulating paste is printed on each of the printed plasma electrodes 15 by a screen printing method to a width smaller than that of the plasma electrodes 15 to form a partition 16 having a predetermined shape. Form and dry.

Thereafter, a plasma electrode 15 made of silver paste in each groove 23 formed on the glass substrate 14 and a nickel paste formed on these grooves 23 and a partition made of an insulating paste formed on the plasma electrode 15 are formed. Baking at a temperature of 480 ° C. to 580 ° C.

Here, after baking the silver electrode 24 made of silver paste, a so-called frit seal is performed as a post-process, so that a temperature of about 450 ° C. to 470 ° C. is applied to the silver electrode 24 at this time. The firing temperature of the silver electrode 24 is 48
If the temperature is lower than 0 ° C., the silver paste may melt at the time of frit sealing, causing an unusual reaction and increasing the electric resistance. In addition, the firing temperature is set to 580 due to a request regarding the upper limit of the heat resistance temperature of the glass material as the material of the first substrate.
℃.

After that, through various post-processes,
The silver electrode 24, the plasma electrode 15, and the partition 16 are completed.

Next, each of the discharge regions 12 formed by supporting and fixing the lower portion of the microsheet 13 made of glass or SiO ₂ by the frit 17 provided at the upper end of each partition 16 and the peripheral edge of the glass substrate 14. A gas that can be ionized is sealed in the inside.

Then, the image display device is completed by sequentially laminating the liquid crystal layer 11 as an electro-optical material and the transparent substrate 21 on which the plurality of transparent electrodes 22 are formed on the microsheet 13. As the liquid crystal layer 11, a liquid crystal material such as a nematic liquid crystal is used. Therefore, the alignment layers 18 a and 18 b and the color filter 20 are arranged on the upper and lower portions, and the micro sheet 1
3 and a predetermined gap, and can be easily manufactured by injecting, for example, a nematic liquid crystal between the transparent substrate 21 and the microsheet 13 like a normal liquid crystal cell.

As described above, when manufacturing the image display device according to the present embodiment, a plurality of grooves 23 at predetermined regular intervals are formed on one main surface of the glass substrate 14 as the first substrate by the photolithography technique. A high-precision groove having a predetermined width is formed. Since the silver paste is filled in these grooves to form the silver electrodes 24, the surface on which the silver paste is formed and one main surface of the glass substrate 14 can be easily made parallel. Therefore, in the next step, the groove 2 is formed by screen printing.
By printing a nickel paste in a predetermined shape on 3, the desired first electrode, ie, the plasma electrode 15 is formed without exposing the silver paste.

[0034]

According to the image display device of the present invention, a dielectric film is bonded on a first substrate having a plurality of strip-shaped first electrodes and barrier ribs, and a second film is formed on the second substrate orthogonal to the first substrate.
A second substrate having electrodes is disposed on the dielectric film with an electro-optic material layer interposed therebetween, and a plurality of band-shaped grooves are formed on the first substrate corresponding to the first electrodes, These grooves are filled with silver paste, and the first electrodes made of conductive paste are formed on the respective grooves, so that the electric resistance of the first electrodes can be reduced. It is possible to increase the size of the device, which is a demand at the time.

[0035]

[Brief description of the drawings]

FIG. 1 is a cross-sectional view schematically illustrating an image display device manufactured according to a first embodiment.

FIG. 2 is a cross-sectional view schematically showing a state where each groove is formed on a glass substrate.

FIG. 3 is a cross-sectional view schematically showing a state in which a silver paste is filled in each groove to form a silver electrode.

FIG. 4 is a cross-sectional view schematically showing a state where a plasma electrode is formed on each groove.

FIG. 5 is a cross-sectional view schematically showing a state in which a partition is formed on a plasma electrode.

[Explanation of symbols]

 Reference Signs List 11 liquid crystal layer 12 discharge region 13 microsheet 14 glass substrate 15 plasma electrode 15a anode 15b cathode 16 partition wall 17 frit 18a, 18b alignment layer 19 liquid crystal seal 20 color filter 21 transparent substrate 22 transparent electrode 23 groove 24 silver electrode

Claims (3)

(57) [Claims] 1. A dielectric film is bonded to a first substrate having a plurality of strip-shaped first electrodes and partition walls, and a second substrate having a second electrode orthogonal to the first substrate is formed of an electro-optical material. A plurality of strip-shaped grooves corresponding to the first electrodes are formed on the first substrate, and the grooves are filled with a silver paste; An image display device, wherein the first electrode made of a conductive paste is formed on each groove. 2. The image display device according to claim 1, wherein the conductive paste is a nickel paste. 3. The sintering temperature of the silver paste is 480 ° C.-58.
The image display device according to claim 1, wherein the temperature is 0 ° C.