Liquid crystal display device and method for manufacturing the same

a technology of liquid crystal display and liquid crystal, which is applied in the direction of identification means, instruments, non-linear optics, etc., can solve the problems of uniformity degradation, leakage of light, and increase of ta

Inactive Publication Date: 2005-02-17
ADVANCED DISPLAY
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Benefits of technology

[0018] In accordance with the present invention, there is further provided a liquid crystal display device comprising a sealing material provided on a periphery of a substrate for preventing leakage of liquid crystal, projections formed by etching a film formed on the substrate, and another substrate opposing the substrate being remote therefrom by a gap and being supported by the projections, wherein heights of columnar spacers are varied.

Problems solved by technology

However, many technical drawbacks such as degradations in uniformity of the gap owing to aggregation of spacers, increases in tact caused in spacer dispersing processes, and leakage of light owing to blurs in orientation in proximities of spacers were pointed out in view of such spacer dispersing methods.
Even if it is possible to disperse the spacers in an uniform manner, the presence of variations in spacer diameters (average value ±0.2 μm) make it difficult to neglect variations in the spacers themselves.
However, in putting the above techniques related to columnar spacers into practical use, there was presented a new technical drawback that ambient temperatures need to be considered.
Effects of the spacers of applying uniform pressure to the substrate might not be exhibited and display blurs accompanying degradations in uniformity of the gap will be induced.

Method used

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  • Liquid crystal display device and method for manufacturing the same
  • Liquid crystal display device and method for manufacturing the same
  • Liquid crystal display device and method for manufacturing the same

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embodiment 1

[0034] Arrangements of the liquid crystal display device and a thin film transistor will first be explained. A relationship between an area occupying rate of columnar spacers and ambient temperature will be explained thereafter.

[0035] (1) Basic Arrangements of the Liquid Crystal Display Device

[0036]FIG. 1 is a view showing an arrangement of the liquid crystal display device. FIG. 2 is a view illustrating a condition in which a liquid crystal contacting surface of a color filter substrate formed with columnar spacers is facing up, which is an enlarged view of region IV of FIG. 1.

[0037] A TFT substrate 11 and a color filter substrate 12 are disposed in a mutually opposing manner with a specified gap (not shown) being formed therebetween, and liquid crystal LC is filled into this gap. The TFT substrate 11 is formed with scanning signal wiring 13 and image signal wiring 14 which are mutually intersecting. For controlling a pixel region V enclosed by the wiring 13, 14 through switchin...

embodiment 2

[0048] The present embodiment is characterized in that problems owing to ambient temperatures of columnar spacers are improved by performing a pressurized sealing process in the liquid crystal display device. An outline of the pressurized sealing process and effects thereof will now be explained.

[0049] A thermosetting type sealing material (XN31A manufactured by Mitsui Toatsu Kagaku Kabushiki Kaisha) is applied by means of a dispenser device on a periphery of a TFT substrate or a color filter substrate in an annular manner except for a liquid crystal injection inlet for injecting liquid crystal (a portion forming the injection inlet when the substrates are overlapped). Thereafter, the TFT substrate and the color filter substrate are overlapped and heated to approximately 200° C. whereupon thermosetting thereof is performed for 1 hour in a condition of 60,000 Pa. It should be noted that MACROROD PF-41 (manufactured by Nippon Electric Glass Co., Ltd.) is mixed to the sealing material...

embodiment 3

[0057] The present embodiment is characterized in that two types of spacers of different height are disposed. As illustrated in FIG. 6(a), a difference in height L is set for a first group of columnar spacers 23A and a second group of columnar spacers 23B. When the glass substrate 3 is subjected to a compressing pressure P0 and an amount of compression a of the columnar spacers 23B is not more than L, only reaction force f1 of the second group of columnar spacers 23B acts on the substrate (FIG. 6(b)). Thus, the reaction force f1 of the columnar spacers 23B will be smaller than a reaction force caused when employing columnar spacers 23 of identical height (a sum of f1 and f2) (see FIG. 6(c)). Consequently, the amount of compressive deformation of the columnar spacers might be larger in case of varying heights of the columnar spacers compared to a case in which the heights are identical under conditions that area occupying ratio of columnar spacers and compressive force of columnar sp...

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Abstract

A liquid crystal display device comprising a sealing material provided on a periphery of a substrate, projections formed by etching a film formed on the substrate, and another substrate opposing the substrate being remote therefrom by a gap and being supported by the projections. An area occupying rate of the projections portions with respect to a region enclosed by the sealing material is not less than 0.0001 and not more than 0.003. It is possible to obtain a liquid crystal display device free of display blurs at the time of using the same in a high temperature condition and with which no bubbles are generated when using the same in a low temperature condition by setting the area occupying ratio for the columnar spacers to be an optimal value.

Description

BACKGROUND OF THE INVENTION [0001] The present invention relates to a liquid crystal display device and a method for manufacturing the same wherein the device employs columnar spacers (projections) for maintaining a gap into which liquid crystal is injected constant. [0002] A liquid crystal display device is arranged to create images by varying an amount of light 5 from a backlight light source by controlling conditions of orientation of liquid crystal molecules through a thin film transistor (TFT) 1 as illustrated in FIG. 9. In case liquid crystal LC is employed as optical shutters, accuracies of thicknesses of liquid crystal layers (gaps) account for influences on display characteristics such as light transmission rate, contrast ratio or response speed, so that it is crucial to maintain the thickness constant. It is generally the case that this is achieved through bead-like minute particles called spacers 4. The spacers 4 are composed of spherical silica or divinyl benzene polymer...

Claims

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Application Information

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IPC IPC(8): G02F1/1335G02F1/1339G09F9/00
CPCG02F1/13394G02F1/133512G02F1/1339
InventorTAMATANI, AKIRANIWANO, YASUNORI
OwnerADVANCED DISPLAY