JP2006267776A - Liquid crystal display device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a color filter substrate for a liquid crystal display device which can be easily inspected even after panel formation. <P>SOLUTION: In this liquid crystal display device configured by laminating an active matrix substrate and a color filter substrate through a seal, and sealing a liquid crystal layer into a region surrounded by the seal between them, and deciding a display area, the color filter substrate is provided with a transparent substrate, color filters in a plurality of colors for color display formed like a matrix at the upper part of the display area of the substrate, a light shielding pattern formed between the adjacent color filters at the upper part of the display area of the substrate, a transparent electrode formed at the upper part of the color filter, an alignment layer formed at the upper part of the transparent electrode and the first inspection pattern of at least one of the color filter formed outside the alignment layer and the light shielding pattern at the upper part of the transparent substrate. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a liquid crystal display device, and more particularly to a liquid crystal display device capable of color display.

A liquid crystal display device performs display by applying an electric field to a liquid crystal layer sandwiched between a pair of substrates and controlling the orientation of liquid crystal molecules. In order to apply an electric field, an electrode is formed on each substrate. In order to control the alignment of the liquid crystal molecules when they are off, an alignment film is formed on the electrode. In the transmissive liquid crystal display device, the substrate is composed of a transparent substrate such as a glass substrate, and the electrode is composed of a transparent conductive film such as indium-tin oxide (ITO). In order to enclose the liquid crystal, a seal is disposed outside the display area.
Many liquid crystal display devices having a large number of pixels are formed using an active matrix (or array) substrate and a common electrode substrate. On the active matrix substrate, gate bus lines are arranged in parallel in the row direction, drain bus lines are arranged in parallel in the column direction, and switching elements such as thin film transistors (TFTs) are arranged in a matrix at each intersection. An electrode is connected to each switching element. A common electrode common to all the pixels is disposed on the common electrode substrate.

  In a liquid crystal display device that performs color display, color filters such as red (R), green (G), and blue (B) are formed on a common electrode substrate. A light shielding pattern such as a black matrix is arranged between the color filters as necessary. Since the surface of the color filter and the light-shielding pattern is uneven, the common electrode and the alignment film are formed after the surface is flattened with a flattening film. Spacers are used to keep the spacing between the substrates constant.

In general, a twisted nematic (TN) liquid crystal display device in which liquid crystal molecules rotate between substrates has a narrow viewing angle. As a liquid crystal display device capable of widening the viewing angle, a negative type liquid crystal material having negative dielectric anisotropy and a vertical alignment film for aligning liquid crystal molecules perpendicularly to the substrate surface are used to electrically change the birefringence. 2. Description of the Related Art Vertical alignment (VA) mode liquid crystal display devices that perform display under control are known. A multi-domain VA mode liquid crystal display device in which the direction in which liquid crystal molecules are tilted when an electric field is applied is controlled in a plurality of directions can display images with a wide viewing angle. Projections and slits are used to control the alignment direction of the liquid crystal. For example, a protrusion having a desired shape can be formed using a photoresist material and photolithography. Columnar spacers for controlling the distance between the substrates can also be formed using a photoresist material. It is convenient to form structures such as protrusions and spacers on the common electrode of the color filter substrate. JP, 2002-162629, A In a manufacturing process, it is efficient to form the panel for a plurality of sheets of liquid crystal display on one glass substrate. In order to monitor each process, a test pattern for monitoring is arranged outside the panel area. The components of the active matrix are mainly concerned with electrical characteristics. The thickness of the color filter, the light shielding pattern, the alignment control protrusion, the liquid crystal layer thickness control spacer, etc. of the color filter substrate is mainly a problem. These thicknesses can be monitored by stylus measurement.

  An object of the present invention is to provide a liquid crystal display device capable of color display and easily inspected even after being panelized.

According to one aspect of the present invention,
A liquid crystal display device in which an active matrix substrate and a color filter substrate are bonded via a seal, a liquid crystal layer is sealed in a region surrounded by the seal between the two, and a display region is defined,
The color filter substrate is
A transparent substrate,
A plurality of color filters for color display formed in a matrix above the display area of the substrate;
A light-shielding pattern formed between adjacent color filters above the display area of the substrate;
A transparent electrode formed above the color filter;
An alignment film formed above the transparent electrode;
Above the transparent substrate, the color filter formed outside the alignment film, a first inspection pattern of at least one of a light shielding pattern, and
A liquid crystal display device is provided.

  Since the inspection pattern is formed in the panel region, it remains after the paneling and can be monitored. Since it is not covered with an alignment film, monitoring can be easily performed with high accuracy. By removing the alignment film with a solvent, it is possible to avoid dissolving the inspection pattern.

  Conventionally, inspection patterns have been formed outside the panel region, but due to manufacturing costs, all inspection patterns cannot be measured, and sampling inspections have been performed. However, display defects may be found after the panel is formed, and the panel is divided to measure each component in order to investigate the cause. If the inspection pattern is covered with the alignment film, the thickness of only the inspection pattern cannot be measured with high accuracy. When the alignment film is removed with a solvent such as toluene, protrusions and spacers formed of a resin material such as polyimide, acrylic, and novolac are also dissolved.

  FIG. 1A is a cross-sectional view schematically showing a configuration of a VA mode liquid crystal display device. A color filter substrate 1 and an active matrix substrate 2 face each other, and a liquid crystal layer 3 is sandwiched therebetween to constitute a liquid crystal cell. A seal 4 seals the liquid crystal layer 3. The compensation plate CM compensates for the refractive index anisotropy of the liquid crystal layer. A pair of polarizing plates P1 and P2 are disposed on both sides of the liquid crystal cell.

  FIG. 1B is a plan view schematically showing the configuration of the color filter substrate. On the color filter substrate 1 formed of a glass substrate, R, G, and B color filters 11 are arranged for each pixel region, and a light shielding pattern 12 separates adjacent color filter regions. A common electrode 15 is formed on the color filter 11 and the light shielding pattern 12. On the color filter, a liquid crystal molecule alignment control protrusion 13 and a liquid crystal layer thickness control columnar spacer 14 are arranged. An alignment film 16 is applied on these structures. The inspection pattern 18 is formed in a region outside the alignment film. Instead of the primary color filter, a predation color filter, a combination of the primary color filter and another color filter, or the like can also be used.

  FIG. 1C is a plan view schematically showing the configuration of the active matrix substrate. On the active matrix substrate 2 formed of a glass substrate, gate bus lines 21 are arranged in parallel in the row direction, and drain bus lines 22 are arranged in parallel in the column direction. A TFT 23 is connected to the intersection of the gate bus line 21 and the drain bus line 22. A pixel electrode 24 is connected to the TFT 23. The pixel electrode 24 and the auxiliary capacitor bus line 25 constitute a storage capacitor. An alignment film 26 is applied over these structures. Hereinafter, the arrangement in the glass substrate for producing the color filter substrate as shown in FIG. 1B will be described.

  FIG. 2 shows a first arrangement example of inspection patterns. A plurality of panel areas 1 are defined on the glass substrate 10, and a display area DIS is defined at the center of each panel area 1. An alignment film application region 16 is defined in which the alignment film is applied so as to include the display region. A seal application region 17 is defined in the alignment film application region 16. An inspection pattern placement region 18 for placing the inspection pattern is defined in the panel region 1 and outside the alignment film application region 16. Since the alignment film 16, the seal 4, and the like are not applied to the position area 18 after the paneling, the inspection pattern such as a color filter can be measured.

  FIG. 3 shows a second arrangement example. The alignment film application region 16 is defined so as to include the display region DIS, as in the first arrangement example shown in FIG. In this arrangement example, a seal application region 17 is defined outside the alignment film application region 16. The inspection pattern arrangement area 18 is defined in the panel area 1 and outside the seal application area. Since the alignment film 16, the seal 4, and the like are not applied to the position area 18 after the paneling, the inspection pattern such as a color filter can be measured.

  FIG. 4 shows an example of the third case. The arrangement of the panel area 1, the alignment film application area 16, the seal application area 17, and the inspection pattern arrangement area 18 is the same as that of the first example shown in FIG. The inspection patterns are not arranged in the entire inspection pattern arrangement area 18 but are arranged in the four corner areas 18C of the inspection pattern arrangement area 18. By arranging the inspection patterns at the four corners, the distribution in the panel can be estimated.

  As the inspection pattern, a light shielding pattern inspection pattern may be formed instead of the color filter. More preferably, an inspection pattern for both the color filter and the light shielding pattern is formed. It is preferable to form at least one of the alignment control protrusions of the liquid crystal molecules and the inspection pattern of the spacer for controlling the thickness of the liquid crystal layer. Furthermore, a transparent electrode inspection pattern can be formed.

  FIG. 5 shows an example of the arrangement of inspection patterns to be arranged inside the inspection pattern arrangement area 18. The test pattern of the light shielding pattern 12 is arranged in a stripe shape, and is separated from the test pattern 12 by a predetermined distance d, the test pattern of the R, G, B color filter 11, the alignment control protrusion 13 of the liquid crystal molecules, and the thickness control spacer of the liquid crystal layer. 14 inspection patterns, and further, an inspection pattern of the transparent electrode 15 are arranged. It is possible to inspect the positional deviation of each pattern by measuring the other position of the thickness measurement.

  As mentioned above, although this invention was demonstrated along the Example, this invention is not restrict | limited to these. For example, a similar inspection pattern can be applied to a color liquid crystal display device other than the VA mode. However, in that case, the alignment control protrusions of the liquid crystal molecules are omitted. It is also possible to omit the spacer for controlling the thickness of the liquid crystal layer. It will be apparent to those skilled in the art that other various modifications, improvements, combinations, and the like can be made. The features of the present invention will be described below.

(Appendix 1)
A liquid crystal display device in which an active matrix substrate and a color filter substrate are bonded via a seal, a liquid crystal layer is sealed in a region surrounded by the seal between the two, and a display region is defined,
The color filter substrate is
A transparent substrate,
A plurality of color filters for color display formed in a matrix above the display area of the substrate;
A light-shielding pattern formed between adjacent color filters above the display area of the substrate;
A transparent electrode formed above the color filter;
An alignment film formed above the transparent electrode;
Above the transparent substrate, the color filter formed outside the alignment film, a first inspection pattern of at least one of a light shielding pattern, and
A liquid crystal display device.

(Appendix 2)
The color filter substrate is formed of a resin material above the color filter, and at least one of alignment control protrusions of liquid crystal molecules, a thickness control spacer of the liquid crystal layer, and
A second inspection pattern of at least one of the alignment control protrusion and the thickness control spacer formed on the outside of the alignment film;
The liquid crystal display device according to appendix 1, further comprising:

(Appendix 3)
The liquid crystal display device according to appendix 1 or 2, wherein the inspection pattern is formed outside the seal in the color filter substrate.

(Appendix 4)
The liquid crystal display device according to any one of supplementary notes 1 to 3, wherein the inspection pattern is formed at least at four corners.

(Appendix 5)
The first inspection pattern includes inspection patterns of both the color filter and the light shielding pattern, and inspection patterns other than the inspection pattern of the light shielding pattern are provided apart from and adjacent to the inspection pattern of the light shielding pattern. The liquid crystal display device according to any one of appendices 1 to 4.

(Appendix 6)
A transparent substrate having one or more display regions and a panel region including each display region and defining a substrate region of the liquid crystal display device;
A plurality of color filters for color display formed in a matrix above the display area of the substrate;
A light-shielding pattern formed between adjacent color filters above the display area of the substrate;
A transparent electrode formed above the color filter;
An alignment film formed above the transparent electrode;
Above the substrate, the color filter formed on the outside of the alignment film and on the inside of the panel region, at least one first inspection pattern of a light shielding pattern, and
A color filter substrate for a liquid crystal display device.

It is sectional drawing which shows the structure of a VA mode liquid crystal display device roughly, and the top view of a color filter substrate. It is a top view of an active matrix substrate. It is a top view which shows the 1st example of arrangement | positioning of the test | inspection pattern arrangement | positioning area | region of a color filter board | substrate. It is a top view which shows the 2nd example of arrangement | positioning of the test | inspection pattern arrangement | positioning area | region of a color filter board | substrate. It is a top view which shows the example of arrangement | positioning of the test pattern in the test pattern arrangement | positioning area | region of a color filter board | substrate. It is a top view which shows the relative arrangement example of each test | inspection pattern within the test | inspection pattern arrangement | positioning area | region of a color filter board | substrate.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Color filter substrate 2 Active matrix substrate 3 Liquid crystal layer 4 Seal P Polarizing plate CM Compensation plate 11 Color filter 12 Light-shielding pattern 13 Protrusion for alignment control (of liquid crystal molecules) 14 Thickness control spacer (of liquid crystal layer) 15 Common electrode 16 Alignment film 17 Inspection pattern 21 Gate bus line 22 Drain bus line 23 TFT (Thin Film Transistor)
24 pixel electrode 25 auxiliary capacity bus line 26 alignment film

Claims (5)

A liquid crystal display device in which an active matrix substrate and a color filter substrate are bonded via a seal, a liquid crystal layer is sealed in a region surrounded by the seal between the two, and a display region is defined,
The color filter substrate is
A transparent substrate,
A plurality of color filters for color display formed in a matrix above the display area of the substrate;
A light-shielding pattern formed between adjacent color filters above the display area of the substrate;
A transparent electrode formed above the color filter;
An alignment film formed above the transparent electrode;
Above the transparent substrate, the color filter formed outside the alignment film, a first inspection pattern of at least one of a light shielding pattern, and
A liquid crystal display device. The color filter substrate is formed of a resin material above the color filter, and at least one of alignment control protrusions of liquid crystal molecules, a thickness control spacer of the liquid crystal layer, and
A second inspection pattern of at least one of the alignment control protrusion and the thickness control spacer formed on the outside of the alignment film;
The liquid crystal display device according to claim 1, further comprising:   3. The liquid crystal display device according to claim 1, wherein the inspection pattern is formed outside a seal in the color filter substrate.   The liquid crystal display device according to claim 1, wherein the inspection pattern is formed in at least four corners.   The first inspection pattern includes both inspection patterns of the color filter and the light shielding pattern, and inspection patterns other than the inspection pattern of the light shielding pattern are provided adjacent to and apart from the inspection pattern of the light shielding pattern. The liquid crystal display device according to claim 1.

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