JPH0434409A - Structure and production of lcd panel - Google Patents

Abstract

PURPOSE:To decrease the mismatch of the chiral concn. and cell state at the time of liquid crystal injection and to improve a yield by integrally forming a cell for display consisting of one display region and a cell for evaluation consisting of >=2 pieces of small regions on a substrate and forming these cells in such a manner that the respective cells can be subjected to the same driving. CONSTITUTION:The LC panel structure is provided with the display region 11 constituting the cell for display and the plural small regions 14-1 to 14-n constituting the cell for evaluation which is in the same empty cell state as the empty cells state of the display region 11 and is formed with X electrodes 12 and Y electrodes 13 so as to be subjected to the same driving on the same substrate 10. The liquid crystals 15-1 to 15-n of the different chiral concns. are injected into the small regions 14-1 to 14-n of the LC panel structure in this case and the normal injection to the display region 11 is executed after the optimum chiral concn. is investigated. The mismatch of the chiral concn. and cell state at the time of the liquid crystal injection is prevented in this way and contribution is made to the improvement in the yield.

Description

[Detailed Description of the Invention] [Summary] Regarding the structure and manufacturing method of a liquid crystal display panel used in display devices such as OA equipment, an object of the present invention is to reduce mismatch between chiral concentration and cell state during liquid crystal injection and improve yield. In an STN-LCD panel, in which two transparent insulating substrates each having a transparent electrode and an alignment film are placed facing each other at a predetermined distance, and a liquid crystal is sealed in the facing gap, the above-mentioned panel has at least A display cell consisting of one display area and an evaluation cell consisting of at least two or more small areas are integrally formed on a substrate, and each of these cells is configured to be driven simultaneously.

[Industrial application field]

The present invention relates to the structure and manufacturing method of a liquid crystal display panel used in display devices such as office automation equipment.

[Conventional technology]

A conventional STN-LCD panel (super twisted nematic liquid crystal display panel) is, as shown in FIG.
A pair of glass substrates 3 and 3' are placed opposite to each other with a minute interval, the periphery is sealed with a sealing material 4 to form a cell, and a liquid crystal 5 is injected into the cell.The twist angle of the liquid crystal is that of a normal LCD.
It is thicker than the panel and has a temperature of about 240 to 270°C.

In such an STN-LCD panel, a chiral agent is mixed into the liquid crystal, but the chiral concentration needs to be delicately adjusted depending on the condition of the substrate surface and the distance between the substrates. In the production of this STN-LCD/channel, when determining the optimal chiral concentration of the liquid crystal to be injected into the manufactured empty cell, several other cells (evaluation cells) are used inside the empty cell. were filled with liquid crystals of different chiral concentrations, and the optimum concentration was determined to be one that did not cause defects.

[Problem to be solved by the invention]

The cell [A] to be actually made into a panel and the cell [B] for evaluation are different in the presence or absence of a color filter, substrate area, substrate surface condition, process, drive, etc., so the alignment film is different between [A] and [B]. It is not possible to match panel conditions such as thickness, liquid crystal alignment state, cell thickness, etc. and drive conditions. Moreover, the paneling conditions for cell [A] also change between lofts. Therefore, a problem arises in that the optimum chiral concentration determined by the evaluation cell deviates significantly from the optimum conditions for the actual panel. In that case, defects such as stripe domains or microdomains occur in panel [A], resulting in a significant decrease in yield.

In view of the above conventional problems, it is an object of the present invention to provide a structure and manufacturing method for an LCD panel that reduces the mismatch between chiral concentration and cell state during liquid crystal injection and increases yield.

[Failure to solve the problem]

FIG. 1 shows a diagram explaining the principle of the present invention.

As shown in the figure, the LCD panel structure of the present invention has a display area 11 constituting a display cell on the same substrate 10, and a display area 11 which is in the same empty cell state and can be driven in the same way. It is characterized in that a plurality of small regions 14-1 to 14-, which constitute an evaluation cell in which an X electrode 12 and a Y electrode 13 are formed, are provided.

Further, the method for manufacturing an LCD panel of the present invention includes injecting liquid crystals 15-1 to 15-9 having different chiral concentrations into the small regions 14-1 to 14-0 of the CD panel structure described above, and checking the optimum chiral concentration. , the main injection into the display area 11 is performed.

[For production]

Liquid crystals 15-1 to 15-, having different chiral concentrations are injected into the small regions 14-1 to 14, and the X electrode 12 and the Y electrode 13 are driven to determine the optimum chiral concentration by evaluating the presence or absence of defects. However, by injecting liquid crystal having the optimum chiral concentration into the display region 11, mismatch between the chiral concentration and the cell state can be prevented.

〔Example〕

FIG. 2 is a diagram showing one embodiment of the LCD panel structure of the present invention.

In the figure, 10a is an upper substrate, 10b (indicated by a dotted line) is a lower substrate facing the upper substrate 10a at a minute interval, and each has a plurality of protrusions 16-1 to 16-16. -, , and alignment films are formed. Furthermore, an X electrode 12.12' is provided on one substrate (lower substrate 10b in the figure), and a Y electrode 13.13' is provided on the other substrate (upper substrate 10a in the figure). Also, the upper and lower substrates 10a.

Between 10b is a seal pattern 17 surrounding the display area 11 and a plurality of small areas 14-1 to 14-9 used for panel evaluation.
A seal pattern 18 surrounding the is provided. Note that a liquid crystal injection port 19 is provided in the seal pattern 17 surrounding the display area 11.
is provided. Further, the projections 16-1 to 16- of the upper and lower substrates 10a and 10b. and small areas 14-1 to 14 for evaluation.
-, , correspond to each other, each of the protrusions 16-1 to 16-7 is provided with a liquid crystal injection opening 20, and one of the substrates of the protrusions (lower substrate 10b in the figure) is provided with a liquid crystal injection opening 20 for evaluation. One end of the Y electrode 13' in the small regions 14-1 to IL is drawn out.

It should be noted that although the above embodiment has been described with respect to a simple matrix type LCD panel, it is also applicable to an active matrix type LCD panel.

Next, a method for manufacturing an LCD panel according to the present invention will be described, and in this case as well, a simple matrix type LCD panel will be explained as an example.

In the method of the present invention, first, before injecting liquid crystal into the display area 11,
Liquid crystals having different chiral concentrations are injected into the evaluation small regions 14-1 to 14-h, respectively. Next, each cell in the small regions 14-1 to 14-h is driven using the X electrode 12' and the Y electrode 13', and the presence or absence of defects is checked to determine the optimum chiral concentration. Next, this liquid crystal with the optimum chiral concentration is injected into the display area 11 through the injection opening 19 and sealed, and then the substrates 10a and 10b are cut along the line A-A to form the display area, which is the part that will actually be used. Small regions 14-1 to ILr, which are portions that are not actually used, are separated from 11.

The LCD panel created in this way has display area 1
1 and the small evaluation regions 14-1 to IL have the same conditions such as alignment film and cell thickness, so the small evaluation regions 14-1 to 14
- The liquid crystal with the optimum chiral concentration determined in step (a) is displayed in the display area 11.
However, since it is optimized, it is possible to obtain an LCD panel that does not cause defects such as stripe domains and microdomains.

FIG. 3 is a diagram showing another embodiment of the present invention.

In this embodiment, a seal pattern 17 surrounding a display area 11 and a plurality of evaluation small areas 14-1 to 14-1. A seal pattern 18 is formed surrounding the X electrode 12 and an alignment film are formed on the other substrate 10b. When injecting liquid crystal into the display area 11, each small area 14-1 to 14-
After dropping liquid crystals 15-1 to 15-9 with different chiral concentrations onto 1 to 14-n using a dropper 21 or the like, the liquid crystals 15-1 to 15-9 having different chiral concentrations are bonded to the other substrate 10b.
The electrodes 13 are used to drive each cell in the small areas 14-1 to 14-h, the optimum chiral concentration is determined, and then the display area 11
A liquid crystal having an optimum chiral concentration is injected into the periphery, and after sealing the injection port 19, a cut is made along the line A--A.

This embodiment has the same effect as the previous embodiment, and also requires no injection opening and other protrusions for injecting liquid crystal into the small evaluation regions 14-1 to 14-h. This simplifies the board structure.

〔Effect of the invention〕

As explained above, according to the present invention, a small area for chiral concentration evaluation is provided on the same substrate as the display area, and the optimum chiral concentration is determined using the small area prior to injection of liquid crystal into the display area. , it is possible to prevent a mismatch between the chiral concentration and the cell state when liquid crystal is injected, and this greatly contributes to improving the yield.

[Brief explanation of drawings]

Fig. 1 is a diagram explaining the principle of the present invention, Fig. 2 is a diagram showing an embodiment of the invention, Fig. 3 is a diagram showing another embodiment of the invention, and Fig. 4 is a diagram showing a conventional STN-LCD panel. FIG. In the figure, 10.10a and 10b are substrates, 11 is a display area, 12.12' is an X electrode, 13.13' is a Y electrode, 14-1 to 14-, , are small areas, 15-1 to 15- 1. 16-1 to 16- are liquid crystals, 16-1 to 16- are projections, 17 and 18 are seal patterns, 19 is an injection port, and 20 is an injection opening. Figure 12, 12'...×electrode + 3.13'...Y electrode 1 day...°Injection port 20...Injection closing opening Section 4 showing a conventional STN-LCD panel figure

Claims (1)

[Claims] 1. In an STN-LCD panel in which two transparent insulating substrates each having a transparent electrode and an alignment film are opposed to each other with a predetermined interval therebetween, and a liquid crystal is sealed in the opposing gap, the above-mentioned The panel includes a display cell consisting of at least one display area (11) and at least two or more small areas (14_
−_1 to 14_-_n) and a substrate (
10) An LCD panel structure characterized in that the LCD panel structure is formed integrally on the top and is configured such that each cell can be driven in the same way. 2. In the LCD panel structure according to claim 1, each small area (14_-_1 to 14_-_n) in the evaluation cell
The liquid crystal injection port portions (16_-_1 to 16_-_n) have a transparent insulating substrate structure in which each protrusion (16_-_1 to 16_-_n) is protruding.
Injection openings (20) corresponding to _1-16_-_n)
An LCD panel structure having a seal structure composed of a pattern (18) surrounding each small area (14_-_1 to 14_-_n). 3. When injecting liquid crystal into the LCD panel structure according to claim 1, liquid crystals having different chiral concentrations are injected into the small areas (14_-_1 to 14_-_n) to find out the optimum chiral concentration, and then the display area is (11) A method for manufacturing an LCD panel, characterized by performing main injection into the liquid.