JPH09318930A - Plasma address liquid crystal display device and its manufacture - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the manufacture yield by setting nearly the same print conditions for barrier ribs between an effective and an ineffective screen area and making it easy to form the barrier ribs. SOLUTION: A base pattern 16 is printed on substrate glass 4 and nickel paste is printed in layers on the base pattern 16 to form a discharge electrode 5. Cover glass 19 is printed at both the end parts of the discharge electrode 5 and their prolongations. On the discharge electrode 5 and cover glass 19, glass paste with which ceramic of alumina, etc., is mixed is laminated and printed several times by a screen printing method to form the barrier ribs 7. Those barrier ribs 7 are not formed directly on the substrate glass 4, so the printability is superior.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a plasma addressed liquid crystal display device having a structure in which a plasma discharge cell and a liquid crystal panel are superposed, a liquid crystal panel is used for display, and the plasma discharge cell is used for switching liquid crystal pixels, and a manufacturing method thereof. Pertain to.

[0002]

2. Description of the Related Art Conventionally, a so-called plasma addressed liquid crystal display device utilizing discharge plasma has been known as an image display device for driving a liquid crystal. For example, JP-A-4-26
Japanese Patent No. 5931 discloses a plasma addressed liquid crystal (PALC) which uses a liquid crystal panel for display and uses a plasma discharge cell for switching liquid crystal pixels.
The applicant has proposed an image display device of d Liquid Crystal) display type.

A schematic structure of an example of a conventional plasma addressed liquid crystal display device will be described below. FIG. 4 is a plan view of the plasma addressed liquid crystal display device, FIG. 5 is a sectional view of the plasma addressed liquid crystal display device, and FIG. 6 is a manufacturing process diagram of the plasma addressed liquid crystal display device. As shown in FIG. 5, the plasma addressed liquid crystal display device has a structure in which a plasma discharge cell section 2 and a liquid crystal panel section 3 are superposed.

The plasma discharge cell portion 2 has a discharge electrode 5 on the anode side and a discharge electrode 6 on the cathode side formed by printing on the substrate glass 4, a barrier rib (partition) 7 formed by printing, and a thin glass plate 8. And a frit 9 for sticking together.

The liquid crystal panel section 3 comprises a display electrode 11 formed on the liquid crystal glass 10 and a liquid crystal layer 12 provided between the liquid crystal glass 10 and the thin glass plate 8. The liquid crystal glass 10 is non-conductive, optically transparent and has a flat shape. The display electrode 11 is made of a transparent conductive material such as indium tin oxide (ITO) and is optically transparent. A plurality of display electrodes 11 are arranged at equal intervals in parallel with each other in the vertical direction (Y direction shown in FIG. 4) of the display screen. For example, nematic liquid crystal is injected into the liquid crystal layer 12.

The discharge electrodes 5 and 6 are arranged in parallel at a predetermined interval in a direction orthogonal to the display electrode 11, that is, in the horizontal direction of the display screen (X direction shown in FIG. 4). The barrier rib 7 is formed on the discharge electrode 5 on the anode side, and excluding the portion forming the frit 9 on the extension of the discharge electrode 5 on the anode side. This barrier rib 7
Is formed by laminating and printing a plurality of glass pastes containing a ceramic such as alumina by a screen printing method.

The inside of the discharge chamber sealed by the frit 9 is divided by a plurality of barrier ribs 7 and divided into independent discharge cells P. Each discharge cell P
Corresponds to each scanning line on the display screen. The barrier rib 7 also plays a role of regulating the distance between the substrate glass 4 and the thin glass plate 8. Substrate glass 4 and thin glass 8
The distance between and is usually about 200 microns. An ionizable gas is enclosed in the discharge chamber sealed by the frit 9. As the ionizable gas, helium, neon, argon, or a mixed gas thereof is used.

The plasma-addressed liquid crystal display device having such a configuration supplies a video signal to the display electrodes 11 arranged in the vertical (Y) direction with respect to the display screen, and
A discharge cell P corresponding to a scanning line by applying a predetermined voltage between the discharge electrode 5 on the anode side and the discharge electrode 6 on the cathode side
An image is displayed in the effective screen area 14 shown in FIG. 4 by causing a plasma discharge inside.

As shown in FIG. 6, the plasma addressed liquid crystal display device includes a printing process S1, a polishing / frit process S2,
The plasma discharge cell section 2 is formed by the exhaust / gas filling step S3 and the plasma side alignment step S4, and the liquid crystal glass 10 and the plasma discharge cell section 2 formed by the color filter step S5 and the filter side alignment step S6 are assembled into a liquid crystal section. It is manufactured by assembling in step S7 and injecting liquid crystal in liquid crystal injecting step S8.

In the printing step S1, the anode side electrode 5 and the cathode side electrode 6 are formed on the substrate glass 4, and further,
Barrier ribs 7 that are partition walls are formed. In the polishing / frit step S2, the upper end surfaces of the barrier ribs 7 are polished to be smooth, and the frit 9 is used to bond the thin glass plates 8 to form the discharge cells P. Next, in the exhaust / gas filling step S3, the discharge cell P is exhausted to fill the gas and the mercury is scattered. Then, the plasma addressed liquid crystal display device is sequentially sent to the alignment step S4, the liquid crystal part assembling step S7, and the liquid crystal injecting step S8 after the exhaust / gas filling step S3 to be manufactured.

By the way, since the plasma addressed liquid crystal display device has a structure in which an image is displayed by using a backlight (not shown) as a light source, the chip tube 13 for exhausting and gas filling in the exhausting / gas filling step S3 is provided. It cannot be installed in the effective screen area 14. Therefore, as shown in FIG. 4, in the plasma addressed liquid crystal display device, the invalid screen area 1 for mounting the tip tube 13 is provided.
5 are provided. Hereinafter, the valid screen area 14 and the invalid screen area 15 will be described with reference to the drawings. FIG. 7 is a plan view of the plasma discharge cell portion in the effective screen area, FIG. 8 is a sectional view of the plasma discharge cell portion in the effective screen area, and FIG. 9 is a plasma discharge cell portion in the ineffective screen area. 10 is a plan view of the portion, FIG. 10 is a cross-sectional view of the plasma discharge cell portion in the invalid screen area, and FIG. 11 is a step at the discharge electrode end.

An effective screen area 14 in which plasma discharge is performed
Then, for example, it has the following structure. As shown in FIG. 8, the discharge electrodes 5 and 6 in the effective screen area 14 are formed by multi-layer printing of a nickel paste on a base 16 formed by printing on the substrate glass 4. Each of the discharge electrodes 5 and 6 is formed by printing this nickel paste in multiple layers in order to adjust its thickness to a predetermined value.

The base 16 is formed to absorb B ₂ O ₃ generated from the nickel paste and to prevent unevenness in transmittance due to sagging of the nickel paste. Since the base 16 and the discharge electrodes 5 and 6 require alignment accuracy, they are printed on the same screen (same pattern).

The discharge electrodes 5 and 6 on the anode side and the cathode side are connected to silver extraction electrodes 17 and 18 in order to maintain the airtightness of the frit 9. In the effective screen area 14, as shown in FIG. 7, an extraction electrode 17 on the anode side is formed on one end side of the substrate glass 4,
On the other hand, the cathode side take-out electrode 18 is formed on the other end side of the substrate glass 4.

The discharge electrode 5 on the anode side is a discharge electrode 17 on the anode side from the left end side of the discharge electrode 5 on the anode side.
It is taken out through the silver take-out pattern 17a.
The discharge electrode 6 on the cathode side is extracted from the left end side of the discharge electrode 6 on the cathode side to the extraction electrode 18 on the cathode side via a silver extraction pattern 18a.

The discharge electrode 5 on the anode side is made longer on the left end side thereof in order to prevent a short circuit at the extraction portion.
Similarly, the discharge electrode 6 on the cathode side has its right end lengthened. Since FIG. 7 shows the state in which the cover glass 19 is covered, the difference in length between both ends of each of the discharge electrodes 5 and 6 cannot be identified, so refer to FIG.

The discharge electrodes 5 and 6 are apt to cause abnormal discharge at the ends thereof due to electric field concentration. Therefore, in order to prevent this abnormal discharge, each of the discharge electrodes 5 and 6 has its both ends covered with the cover glass 19 as shown in FIG. In the effective screen area 14, as shown in FIG. 8, in order to supplement the mechanical strength of the cover glass 19 covering the joint between the silver take-out pattern 17a and the nickel discharge electrode 5, the outer side of the joint is provided. Barrier ribs 7 are formed up to.

In the effective screen area 14, although not shown in the drawing, a barrier rib 7 is also formed at the joint between the extraction pattern 18a on the cathode side and the discharge electrode 6 on the cathode side, and the joint is formed. The mechanical strength of the cover glass 19 which covers it is supplemented.

In the effective screen area 14, in order to prevent mercury scattered in the discharge cell P and the respective extraction electrodes 17, 18 (including the extraction patterns 17a, 18a) from forming an amalgam, each discharge electrode is formed. The frit 9 is applied to the end positions of the cover glass 19 which covers the end parts 5 and 6. The barrier ribs 7 are formed on both sides of the frit 9 at an interval sufficient for applying the frit 9 and at an interval such that the laminated thin glass plate 8 is not broken by the gap between the frit 9 and the barrier rib 7. ing. Frit 9
Patterns 17a, 18a formed on the outer side of the
Is covered with a cover glass 19 with a sufficient space for coating the frit 9 in order to prevent silver migration.

On the other hand, the invalid screen area 15 in which discharge electrodes need not be taken out has the following structure. In the invalid screen area 15, as shown in FIG. 10, barrier ribs 7 are provided on both sides of the frit 9 as in the effective screen area 14 in order to prevent the thin glass plate 8 from being broken. The flit 9 in the invalid screen area 15 is formed continuously with the frit 9 in the valid screen area 14. Therefore, in the invalid screen area 15, the positional relationship between the barrier rib 7 and the frit 9 at the X-axis end is the same as that in the effective screen area 14.

In the invalid screen area 15, in order to make the printability, the shape after printing, and the strength of the barrier rib 7 uniform over the entire surface,
Similar to the effective screen area 14, a base 16 and discharge electrodes 5 and 6 are provided. However, since discharge is not performed, in the invalid screen area 15, each extraction electrode 17, 18 and each extraction pattern 17a, 18a.
No cover glass 19 is provided to cover the.

[0022]

By the way, in the conventional plasma addressed liquid crystal display device, in forming the invalid screen area 15 shown in FIGS. 9 and 10, the following problems occur in the process of printing the barrier ribs 7. occured. That is,
In the conventional plasma addressed liquid crystal display device, when printing the barrier rib 7 of the invalid screen area 15, as shown in FIG. 11, the end surface (X-axis direction) shape of the base 16 and the discharge electrodes 5 and 6 has a height of 50 microns or more. Since there is a right-angled step having a certain height, a thin line with a small amount of paste discharged such as the barrier rib 7 is apt to cause so-called rib chipping in which this step is not printed.

Further, in the conventional plasma addressed liquid crystal display device, as shown in FIG. 10, the barrier rib 7 of the invalid screen area 15 includes a portion directly printed on the substrate glass 4. In this part, the surface to be printed is smooth as compared with the discharge electrode 5 and the cover glass 19 and thus the surface area is small, so that the adhesiveness of the discharged paste is poor and it is difficult to print.

On the other hand, in the effective screen area 14 where squeezing is performed at the same time, the take-out patterns 17a, 18a and the cover glass 19 are printed with a thickness of 20 μm or more, so that in the portion directly printed on the substrate glass 4. The squeegee printing pressure became weak, and it was difficult to print the paste for forming the barrier ribs 7.

As a result, in the invalid screen area 15, there is a problem that the manufacturing allowance when the squeegee printing pressure becomes weak is narrow. As described above, the conventional plasma addressed liquid crystal display device has a problem that rib printing is likely to occur in the invalid screen area 15 when the barrier rib 7 is printed, and the manufacturing yield is deteriorated.

As a solution to such a problem, it was considered to make the pattern of the base 16 and the discharge electrodes 5 and 6 longer than the barrier rib 7 in the invalid screen area 15. However, in order to prevent the thin glass plate 8 from breaking, the distance between the barrier rib 7 and the frit 9 must be 1 mm or less, and further, the positioning accuracy of the base 16, the discharge electrodes 5, 6, and the barrier rib 7, In consideration of the fact that the paste easily drips at the end of the discharge electrode and it is difficult to control the printing position, the above-described method of extending the pattern of the base 16 and the discharge electrodes 5 and 6 beyond the barrier rib 7 has a very narrow manufacturing allowance. found.

In order to solve the above problems, the present invention provides
It is an object of the present invention to provide a plasma addressed liquid crystal display device and manufacturing method thereof in which the printing conditions of the barrier ribs are made substantially the same in the effective screen area and the ineffective screen area to facilitate the formation of the barrier ribs and improve the manufacturing yield.

[0028]

In order to solve the above-mentioned problems, a plasma addressed liquid crystal display device according to the present invention comprises:
It is characterized in that a cover glass for preventing abnormal discharge formed by printing on the end of the discharge electrode of the plasma discharge cell is also provided in the invalid screen region where it is not necessary to take out the discharge electrode.

In the plasma addressed liquid crystal display device, the discharge electrode end is covered with a cover glass over both the effective screen area and the ineffective screen area, and barrier ribs are formed on the discharge electrode and the cover glass by printing. Therefore, according to the present invention, the printing conditions for forming the barrier ribs are substantially the same in the effective screen area and the ineffective screen area, and the barrier ribs are satisfactorily formed over all the areas to be printed.

Further, in the method of manufacturing a plasma addressed liquid crystal display device according to the present invention, a cover glass for preventing abnormal discharge formed by printing on the discharge electrode end of the plasma discharge cell is provided with an ineffective screen in which discharge electrode need not be taken out. It is characterized in that it is formed extending in the region.

In the plasma addressed liquid crystal display device, since the discharge electrode ends are covered with the cover glass over both the effective screen area and the ineffective screen area, barrier ribs are formed between the effective screen area and the ineffective screen area. Printing conditions are almost the same. Therefore, the defect that the barrier ribs are not partially printed is eliminated, and the yield of the barrier rib formation process is improved.

[0032]

Embodiments of the present invention will be described below with reference to the accompanying drawings. Note that the same drawings and reference numerals are used for the same parts as in the related art, and detailed description thereof will be omitted. FIG. 1 is a plan view of a plasma discharge cell portion of an invalid screen area 15 of a plasma addressed liquid crystal display device 1 according to the present invention, and FIG. 2 is a plasma discharge of an invalid screen area 15 of the plasma addressed liquid crystal display device 1. FIG. 3 shows a cross-sectional view of the cell portion, and FIG. 3 shows an explanatory view of the step shape of the discharge electrode end of the plasma addressed liquid crystal display device 1 according to the present invention.

The plasma addressed liquid crystal display device 1 is shown in FIG.
Further, as shown in FIG. 2, in the plasma discharge cell portion 2 of the invalid screen area 15, a plurality of discharge electrodes 5 and 6 are formed on the substrate glass 4. In the plasma addressed liquid crystal display device 1, since it is not necessary to cause discharge in the invalid screen area 15, these discharge electrodes 5, 6
The extraction electrodes 17 and 18 are not provided.

In the plasma addressed liquid crystal display device 1, the ends of the discharge electrodes 5 and 6 are covered with a cover glass 19 in the invalid screen area 15.
Barrier ribs are formed on the surface 9. That is, in the plasma addressed liquid crystal display device 1, the invalid screen area 15
Also in the same manner as in the effective screen area 14, each discharge electrode 5,
Similarly to the effective screen area 14, the outside of the discharge cell P sealed by the frit 9 is covered with the cover glass 1 as well as the end portion of the cover glass 19.
The structure is covered with 9.

This cover glass 19 is formed on each discharge electrode 5,
It is formed by printing the glass paste with a large discharge amount over the stepped portion of 6. Cover glass 19
2 and 3, the step portion after printing the cover glass 19 has a gentle slope (for example, an inclination of 60 degrees or less).
When forming the cover glass 19, the paste is allowed to drip on the surface of the substrate glass 4 having a low printing surface so that the step difference after printing the cover glass 19 is 50 μm or less.

The plasma addressed liquid crystal display device 1
Then, the barrier rib 7 is printed after the cover glass 19 is formed in this way. Therefore, in the plasma addressed liquid crystal display device 1, the barrier ribs 7 formed by the printing process are printed on the discharge electrodes 5 or the cover glass 19. Therefore, in the plasma addressed liquid crystal display device 1, the barrier rib 7 is not directly printed on any part of the substrate glass 4.

As described above, in the plasma addressed liquid crystal display device 1, the effective screen area 1 is not limited to the effective screen area 15.
By providing the cover glass 19 as in the case of 4, the printing conditions when forming the barrier ribs 7 are substantially the same in the effective screen area 14 and the ineffective screen area 15. That is, in the plasma addressed liquid crystal display device 1, since the heights of the printing surfaces which are squeezed simultaneously are the same in the effective screen area 14 and the ineffective screen area 15, the squeegee printing pressure becomes uniform and the printability difference is eliminated.

Therefore, the plasma addressed liquid crystal display device 1
In the above, the so-called rib chipping defect in which the barrier rib 7 is not printed partially does not occur. Further, in the plasma addressed liquid crystal display device 1, since the height of the step portion of each discharge electrode 5, 6 is 50 μm or less, and the height of the step portion is low, the reliability of the barrier rib 7 at the time of printing is high. It is possible to secure the sex.

Further, in the plasma addressed liquid crystal display device 1, the barrier ribs 7 are printed not on the substrate glass 4 where the paste is hard to print due to the smoothness and small surface area, but on the discharge electrode having a large surface area and the cover glass 19. Be seen. Therefore, in the plasma addressed liquid crystal display device 1,
In the printing process of the barrier ribs 7, the adhesiveness of the discharged paste is improved and the manufacturing allowance for the squeegee printing pressure is widened.

In the plasma addressed liquid crystal display device 1, since the cover glass 19 covering the discharge electrodes 5 in the invalid screen area 15 is formed with a gentle gradient, the surface area on which the barrier ribs 7 are printed is further increased by this gradient portion, The reliability of the barrier rib 7 during printing can be ensured.

[0041]

As described above, in the plasma addressed liquid crystal display device according to the present invention, the cover glass for preventing abnormal discharge formed on the discharge electrode end of the plasma discharge cell by printing does not need to take out the discharge electrode. Since it is also provided in the invalid screen area, the printing conditions for forming the barrier ribs are substantially the same in the valid screen area and the invalid screen area, and the barrier ribs are formed uniformly and satisfactorily over all the areas to be printed.

Further, in the method of manufacturing the plasma addressed liquid crystal display device according to the present invention, the cover glass for preventing abnormal discharge formed on the discharge electrode end of the plasma discharge cell by printing is provided with an invalid screen in which discharge electrode need not be taken out. Since it is formed by extending the area, the printing conditions for forming barrier ribs in the effective screen area and the ineffective screen area are almost the same, the defect that the barrier ribs are not partially printed is eliminated, and the yield of the barrier rib forming process is improved. It

[Brief description of drawings]

FIG. 1 is a plan view of a plasma discharge cell portion in an invalid screen area of a plasma addressed liquid crystal display device according to the present invention.

FIG. 2 is a cross-sectional view of a plasma discharge cell portion in an invalid screen area of a plasma addressed liquid crystal display device according to the present invention.

FIG. 3 is an explanatory diagram showing a step shape of a discharge electrode end of the plasma addressed liquid crystal display device according to the present invention.

FIG. 4 is a plan view of a plasma addressed liquid crystal display device.

FIG. 5 is a cross-sectional view of a plasma addressed liquid crystal display device.

FIG. 6 is a manufacturing process diagram of a plasma addressed liquid crystal display device.

FIG. 7 is a plan view of a plasma discharge cell portion in an effective screen area.

FIG. 8 is a cross-sectional view of a plasma discharge cell portion in an effective screen area.

FIG. 9 is a plan view of a plasma discharge cell portion in an invalid screen area of a conventional plasma addressed liquid crystal display device.

FIG. 10 is a cross-sectional view of a plasma discharge cell portion in an invalid screen area of a conventional plasma addressed liquid crystal display device.

FIG. 11 is an explanatory diagram showing a step at the discharge electrode end in the invalid screen area of the conventional plasma addressed liquid crystal display device.

[Explanation of reference numerals] 1 plasma addressed liquid crystal display device, 2 plasma discharge cell section, 3 liquid crystal panel section, 4 substrate glass, 5, 6
Discharge electrode, 7 barrier rib, 8 thin glass, 9 frit, 10 liquid crystal glass, 11 display electrode, 12 liquid crystal layer, 13 chip tube, 14 effective screen area, 15 ineffective screen area, 16 base, 17, 18 extraction electrode, 1
9 Cover glass, P discharge cell

Claims (6)

[Claims] 1. A plasma addressed liquid crystal display device in which a plasma discharge cell portion and a liquid crystal panel portion, in which barrier ribs for forming a plasma discharge cell are formed over a discharge electrode by using a printing process, are overlapped with each other. A plasma addressed liquid crystal display device characterized in that a cover glass for preventing abnormal discharge formed by printing on the discharge electrode end of a discharge cell is also provided in an invalid screen area where discharge electrodes are not required to be taken out. 2. The plasma addressed liquid crystal display device according to claim 1, wherein the edge of the discharge electrode is covered with the cover glass to make the gradient of the step at the end of the discharge electrode gentle. 3. The plasma addressed liquid crystal display device according to claim 1, wherein the step difference at the end of the discharge electrode after being covered with the cover glass is 50 μm or less. 4. A method of manufacturing a plasma addressed liquid crystal display device in which a plasma discharge cell portion, in which a barrier rib for forming a plasma discharge cell is formed over a discharge electrode by using a printing process, and a liquid crystal panel portion are overlapped with each other. A plasma-addressed liquid crystal display device characterized in that a cover glass for preventing abnormal discharge formed by printing on a discharge electrode end of a plasma discharge cell is extended to an invalid screen region where discharge electrodes are not required to be taken out. Production method. 5. The method of manufacturing a plasma addressed liquid crystal display device according to claim 4, wherein the edge of the discharge electrode is covered with the cover glass to make the slope of the step of the discharge electrode gentle. . 6. The method of manufacturing a plasma addressed liquid crystal display device according to claim 4, wherein a step difference of the discharge electrode end after covering with the cover glass is set to 50 μm or less.