JP2006163433A - Liquid crystal display device and manufacturing method thereof - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an in-surface response type liquid crystal display device of high display quality which prevents light absence due to a spacer, has a sufficiently high contrast, and provides no rough feel on a display surface. <P>SOLUTION: A projection pattern 32 is provided below an alignment control film 24 on an electrode substrate 100a and partially on a gate wire and/or a source wire 21, a spacer 30a arranged on the projection pattern 32 defines a gap between the electrode substrate 100a and a color filter substrate 101, and at least one of the alignment control film 24 on the electrode substrate 100a and an alignment control film 29 on the color filter substrate 101 is not brought into contact with spacers 30a arranged in other regions, so light absence due to flawing of the alignment control films 24 and 29 caused by movement of spacers 30a is prevented to solve the problem. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an in-plane response type liquid crystal display device, and more particularly to a spacer material and device configuration for preventing light leakage in a black display state caused by a spacer that defines a panel gap.

Liquid crystal display devices are widely used as display elements for wristwatches, calculators, and the like because they are thin, lightweight, and have low power consumption. In particular, TN liquid crystal display devices that are actively driven by thin film transistors (TFTs) or the like are spreading to areas where CRTs have conventionally been used as display elements for word processors, personal computers, and the like.
However, this TN type liquid crystal display device has a problem that the viewing angle is generally narrow, and it is observed as contrast reduction and gradation inversion when observed from an oblique direction. In order to solve this problem, an in-plane response type liquid crystal display device has been devised. The operation principle of this in-plane response type liquid crystal display device will be described with reference to FIG.
8A and 8B are schematic views showing the structure of a general in-plane response type liquid crystal display device. In the figure, 1a and 1b are comb-shaped electrodes formed on the same substrate, 2 is a liquid crystal molecule, 3 is an electrode substrate on which a plurality of comb-shaped electrodes 1a and 1b are formed, 4 is a counter substrate, and 5 is a comb-shaped electrode 1a. 1 is the equipotential line of the electric field applied between 1b, 6 is the incident light, 7 and 8 are polarizing plates having a transmission axis in the direction of the arrow, 9 is the outgoing transmitted light, and 10 is the orientation direction of the liquid crystal. . 8A shows a liquid crystal alignment state when no voltage is applied between the pair of comb electrodes 1a and 1b, and FIG. 8B shows a liquid crystal alignment state when a voltage is applied between the comb electrodes 1a and 1b. Show.

When no voltage is applied, the liquid crystal molecules 2 are aligned as in the alignment direction 10 in FIG. At this time, if the transmission axis of the polarizing plate 7 is aligned with the orientation direction 10 and the polarizing plate 8 is arranged so as to be orthogonal to the polarizing direction, the incident light 6 cannot pass through the polarizing plate 8 and is in a black (dark) state. Become. On the other hand, when a voltage is applied between the comb electrodes 1a and 1b, as shown in FIG. 8B, an electric field is generated substantially parallel to the substrate surface, and the alignment direction of the liquid crystal molecules 2 changes. In other words, since the birefringence of the liquid crystal layer changes, the incident light 6 passes through the polarizing plate 8 and enters a white (bright) state. That is, in the in-plane response type liquid crystal display device, the black (dark) state is the linearly polarized incident light 6 transmitted through one polarizing plate 7 in which the alignment direction 10 of the liquid crystal molecules 2 coincides with the absorption axis or transmission axis. On the other hand, the liquid crystal layer has no effect and reaches the other polarizing plate 8 whose transmission axis or absorption axis is orthogonal to the previous polarizing plate 7, and is obtained by being unable to transmit this polarizing plate 8. is there.
Thus, in the in-plane response type liquid crystal display device, the liquid crystal molecules 2 respond almost parallel to the substrate surface by applying / not applying voltage. Therefore, even if the viewing direction changes, the optical contribution of the liquid crystal molecules 2 hardly changes. Therefore, there is no deterioration in contrast and display quality due to viewing angle, and extremely excellent viewing angle characteristics are exhibited.

However, in an actual in-plane response type liquid crystal display device, an axial misalignment occurs as shown in FIG. 9 in the vicinity of the spacer that defines the panel gap, and birefringence occurs with respect to incident light, resulting in elliptically polarized light. Therefore, there is a problem that it can be transmitted through the other polarizing plate and is observed as light leakage in a black (dark) state. In FIG. 9, 11 and 13 are portions where the liquid crystal alignment is disturbed, 12 is a spacer, 14 is an alignment control film provided on the counter substrate 4, and 15 is an alignment control film provided on the electrode substrate 3. In the drawings, the same or corresponding parts are denoted by the same reference numerals, and description thereof is omitted.
The disorder of the liquid crystal alignment takes the form shown in FIG. 9A or FIG. 9B or a combination of both depending on the combination of the material of the spacer 12 and the material of the liquid crystal molecules 2. In addition, since the manner of disturbance varies depending on the surface state of the spacer 12, it is not a regular disturbance but an irregular disturbance. At this time, in the portions 11 and 13 where the liquid crystal alignment is disturbed, the light incident from the lower side of the panel is transmitted to the upper side of the panel due to the influence of the birefringence of the liquid crystal layer, and is observed as light leakage. The contrast ratio (brightness in white (bright) state (transmittance)) / (brightness in black (dark) state (transmittance), which is one of the display characteristics of liquid crystal display elements, is particularly noticeable during black display. ) Has a problem that the luminance (transmittance) in the black state decreases because of an increase. In addition, the panel in which light is lost has a problem that the display surface becomes rough in visual observation.

  Further, when the spacer 12 damages the surfaces of the alignment control films 14 and 15, an abnormal alignment region may be generated and observed as light leakage in a black (dark) state. This phenomenon will be described with reference to FIG. In the figure, reference numerals 14a and 15a denote alignment control films in the vicinity of the spacer 12, and reference numerals 16 and 17 denote portions where the liquid crystal alignment is disturbed. In general, the material of the spacer 12 is a simple substance such as silica, divinylbenzene, acrylate resin or the like, and is not physically or chemically bound to the alignment control film 14 or the alignment control film 15 inside the panel. Therefore, when a physical vibration or load is applied to the panel, the spacer 12 moves or is pressed against the upper and lower substrates. For this reason, one or both of the alignment control films 14a and 15a in the vicinity of the spacer 12 are damaged, and portions 16 and 17 in which the liquid crystal alignment is disturbed are generated. The portions 16 and 17 in which the liquid crystal alignment is disturbed are observed as light leakage in a black (dark) state, and there is a problem that the display surface is roughened in contrast reduction or visual observation.

As a method for solving the above problems, in a conventional liquid crystal display device, as a method for dispersing and fixing spacers, for example, in Patent Document 1, Patent Document 2 or Patent Document 3, the spacer is placed at an arbitrary position on the substrate. A method for selective placement is presented. Patent Documents 4 and 5 propose a liquid crystal display device in which the spacer surface is covered with an adhesive resin such as a thermoplastic resin, and the spacer is fixed on the substrate, and a method for manufacturing the same.
JP-A-4-136916 Japanese Patent Laid-Open No. 4-60517 Japanese Patent Laid-Open No. 9-160051 JP-A-2-120719 JP-A-8-160433

  However, in order to selectively arrange the spacers at arbitrary positions on the substrate, it is necessary to increase the number of manufacturing processes and materials, and there is a problem that the manufacturing cost increases. In addition, when using spacers coated with an adhesive on the surface, the adhesive melts and the adhesion area increases, so the problem is that the light-exiting area increases, and the liquid crystal material is contaminated by the adhesive and thermoplastic resin. There is also a problem that it is necessary to add new equipment investment and a process for reacting an adhesive or a thermoplastic resin.

  The present invention has been made to solve the above-described problems, and prevents light leakage due to the spacer, has a sufficiently high contrast ratio, and has a high display quality in-plane response without a rough impression on the display surface. An object of the present invention is to provide a liquid crystal display device manufacturing method capable of manufacturing a liquid crystal display device and capable of manufacturing the liquid crystal display device without increasing costs.

  A liquid crystal display device according to the present invention includes a first substrate having a plurality of electrodes such as scanning signal lines, video signal lines, and pixel electrodes, a color filter, a light shielding film, and the like, and has a certain distance from the first substrate. A second substrate disposed opposite to the substrate, an alignment control film provided on each of the opposing surfaces of the two substrates, a spacer that defines a gap between the two substrates, and a substrate disposed between the two substrates. In a liquid crystal display device in which a voltage is applied between the electrodes to generate an electric field substantially parallel to the substrate surface and the liquid crystal molecules respond in-plane, scanning is performed below the alignment control film of the first substrate and scanning. A convex pattern is locally provided on one or both of the signal line and the video signal line, and the gap between the first substrate and the second substrate is defined by a spacer arranged on the convex pattern. And spacers placed in other areas At least one of the one substrate alignment layer and the second substrate alignment layer of is that to avoid contact.

  In addition, a first substrate having a plurality of electrodes such as a scanning signal line, a video signal line, and a pixel electrode, a color filter, a light shielding film, and the like, and a first substrate disposed opposite to the first substrate with a certain distance therebetween. Two substrates, an alignment control film provided on opposite surfaces of the two substrates, a spacer for defining a gap between the two substrates, and a liquid crystal disposed between the two substrates, and between the electrodes In a liquid crystal display device in which an electric field is applied to the substrate surface to generate an electric field substantially parallel to the substrate surface and the liquid crystal molecules respond in-plane, it is locally convex on the light shielding film below the alignment control film of the second substrate. The gap between the first substrate and the second substrate is defined by the spacer disposed on the convex pattern, and the alignment control film of the first substrate and the spacer disposed in the other region are provided. At least one of the orientation control films on the second substrate is It is that so as not to touch.

  In addition, a first substrate having a plurality of electrodes such as a scanning signal line, a video signal line, and a pixel electrode, a color filter, a light shielding film, and the like, and a first substrate disposed opposite to the first substrate with a certain distance therebetween. Two substrates, an alignment control film provided on opposite surfaces of the two substrates, a spacer for defining a gap between the two substrates, and a liquid crystal disposed between the two substrates, and between the electrodes In the liquid crystal display device in which an electric field is applied to the substrate surface to generate an electric field substantially parallel to the substrate surface and the liquid crystal molecules respond in-plane, the scanning signal line and the video signal line are below the alignment control film of the first substrate. Locally convex patterns are provided on either or both wirings and below the alignment control film of the second substrate and on the light shielding film so as to overlap each other, and are arranged on the convex pattern. Of the first substrate and the second substrate by the spacers Defining a gap, a spacer positioned other areas, in which at least one of the first alignment layer of the substrate and a second substrate alignment layer of was to avoid contact.

  In addition, a first substrate having a plurality of electrodes such as a scanning signal line, a video signal line, and a pixel electrode, a color filter, a light shielding film, and the like, and a first substrate disposed opposite to the first substrate with a certain distance therebetween. Two substrates, an alignment control film provided on opposite surfaces of the two substrates, a spacer for defining a gap between the two substrates, and a liquid crystal disposed between the two substrates, and between the electrodes In the liquid crystal display device in which an electric field is applied to the substrate surface to generate an electric field substantially parallel to the substrate surface and the liquid crystal molecules respond in-plane, the spacer has a diameter d slightly smaller than the gap D between the two substrates, and D It is assumed that −d> 0.2 μm, and at least one of the alignment control film of the first substrate and the alignment control film of the second substrate is not in contact with the spacer.

In addition, a first substrate having a plurality of electrodes such as a scanning signal line, a video signal line, and a pixel electrode, a color filter, a light shielding film, and the like, and a first substrate disposed opposite to the first substrate with a certain distance therebetween. Two substrates, an alignment control film provided on opposite surfaces of the two substrates, a spacer for defining a gap between the two substrates, and a liquid crystal disposed between the two substrates, and between the electrodes In a liquid crystal display device in which an electric field is applied to the substrate surface to generate an electric field substantially parallel to the substrate surface and the liquid crystal molecules respond in-plane, the internal pressure at which the liquid crystal is disposed is -0.3 kgf / cm ^{2 with} respect to atmospheric pressure. As described above, at least one of the alignment control film of the first substrate and the alignment control film of the second substrate is prevented from contacting the spacer.

  A manufacturing method of a liquid crystal display device according to the present invention includes a first substrate having a plurality of electrodes such as scanning signal lines, video signal lines, and pixel electrodes and an alignment control film, a color filter, a light shielding film, and an alignment control film. A step of forming a panel by disposing a spacer between the second substrates and bonding them with a sealing material that is formed at the outer edge portion between the two substrates and a part of which reaches the substrate end portion to form a liquid crystal injection port The panel is installed in a liquid crystal injector in which a container filled with liquid crystal is installed, and the liquid crystal injector and the panel are evacuated, and the inlet is immersed in the liquid crystal in the container. In this state, the liquid crystal injector is returned to atmospheric pressure, and the liquid crystal is filled into the panel from the inlet by the pressure difference, and then left for a predetermined time, and the alignment control film of the first substrate and the second substrate are placed on the spacer. At least one of the orientation control films of When no touch is obtained so as to produce and a step of sealing the injection port is.

  According to the present invention, a locally convex pattern is provided below the alignment control film of the first substrate and on one or both of the scanning signal line and the video signal line, or the first By providing a locally convex pattern below the orientation control film of the second substrate and on the light-shielding film, a gap between the first substrate and the second substrate is provided by a spacer disposed on the convex pattern. Since the alignment control film of the first substrate and the alignment control film of the second substrate are not in contact with the spacers arranged in other regions, the alignment control is performed by moving the spacers. Light leakage due to scratches on the film can be prevented, and a high-quality liquid crystal display device having a sufficiently high contrast ratio and no rough impression on the display surface can be obtained.

Reference Example 1
Reference examples of the present invention will be described below with reference to the drawings. FIG. 1 is a cross-sectional view showing a manufacturing process of an in-plane response type liquid crystal display device in Reference Example 1 of the present invention. In the figure, 100 is an electrode substrate (first substrate) having a plurality of electrodes such as scanning signal lines, video signal lines and pixel electrodes, 20 is a glass substrate, 21 is a source wiring which is a video signal line, and 22 is A gate insulating film, 23 is a pixel electrode, and 24 is an alignment control film. Reference numeral 101 denotes a color filter substrate (second substrate) that has a color filter, a light shielding film, and the like, and is disposed to face the electrode substrate 100 at a predetermined distance, 25 is a glass substrate, 26 is a pigment or chromium, and the like. A light shielding film made of a metal, 27 a color filter made of a pigment or a dye, 28 an organic or inorganic material, an overcoat film for improving the reliability of the color filter, and 29 an orientation control film. The orientation control films 24 and 29 are provided on the opposing surfaces of the two substrates 100 and 101, respectively. Further, 30 is a spacer for defining a gap between the two substrates 100 and 101, 31 is a liquid crystal disposed between the two substrates 100 and 101, and 40 is a roller necessary for the rubbing process.

  In this reference example, in an in-plane response type liquid crystal display device in which a voltage is applied between electrodes formed on the electrode substrate 100 to generate an electric field substantially parallel to the substrate surface and liquid crystal molecules respond in-plane, the electrode substrate 100 The surface of the spacer 30 that defines the gap between the two substrates of the color filter substrate 101 is a molecular compound having a vinyl group or a polymerization initiator, and one or two or more kinds of polymerizations starting from the vinyl group or the polymerization initiator. A possible monomer was coated with a thermoplastic polymer formed by graft polymerization. As a result, the functional group of the monomer constituting the thermoplastic polymer is bonded to the alignment control films 24 and 29 by the van der Waals force or hydrogen bond, so that the spacer 30 becomes the electrode substrate 100 and the color filter substrate 101. Are fixed to at least one of the substrates.

A branched polymer produced by graft polymerization is called a graft polymer. This is mainly due to the addition of a monomer to this chain and the addition of monomers to grow the branch. can get. The characteristic of the graft polymer is that the monomers constituting the trunk (main chain part) and the branch (branch) are different. On the surface of the spacer 31 in this reference example, there are functional groups of the graft polymerized monomer, such as hydroxyl group, carboxyl group, epoxy group, silyl group, silanol group, isocyanate group and the like. These functional groups are bonded to the alignment control films 24 and 29 by van der Waals force or hydrogen bonds, and the bonded portion is very small, so that the light escape region can be suppressed small. According to this method, light leakage from the spacer 30 portion due to the uniaxial alignment disorder generated around the spacer 30 remains, but the alignment control films 24 and 29 are damaged by the movement of the spacer 30 which was the largest factor. It is possible to prevent light leakage due to lighting.
In addition, light escape from the spacer 30 part can also be prevented by making the thermoplastic polymer which coat | covers the spacer 30 have many long-chain alkyl groups on the surface. This long chain alkyl group is bonded to a graft polymer chain formed by graft polymerization, and preferably has 6 or more carbon atoms. This will be described in detail in Reference Example 2 described later.

Below, the manufacturing method of the liquid crystal display device in this reference example is demonstrated. First, as shown in FIG. 1A, a plurality of electrodes such as a gate wiring that is a scanning signal line, a source wiring 21 that is a video signal line, and a pixel electrode 23 are formed on a glass substrate 20 by photolithography. Then, the electrode substrate 100 is formed. The source wiring 21 was formed of amorphous silicon 0.2 μm, Cr 0.1 μm, and Al 0.3 μm, the gate insulating film 22 was formed of SiN 0.4 μm, and the pixel electrode 23 was formed of Cr 0.1 μm. Further, an orientation control film 24 (AL1044 manufactured by Nippon Synthetic Rubber Co., Ltd.) having a thickness of 0.07 μm is formed on the electrode substrate 100 by a transfer method, and cured by applying heat in an oven at 180 ° C. Next, as shown in FIG. 1B, the cured orientation control film 24 is rubbed using a roller 40 equipped with a nylon rubbing cloth. Thereby, the electrode substrate 100 of the in-plane response type liquid crystal display device that applies an electric field in a direction parallel to the substrate surface is formed. Next, as shown in FIG. 1C, spacers 30 (manufactured by NATCO PAINT: KSE, spacer diameter 4.0 ± 0.2 μm) having functional groups on the surface are sprayed. The dispersion density of the spacers 30 was 300 / cm ^{2 on} average (variation 200 to 400 / cm ² ).

  Subsequently, as shown in FIG. 1D, a light shielding film 26 made of a metal such as a pigment or chromium, a color filter 27 made of a pigment or a dye, an organic or inorganic material on another glass substrate 25 by a photolithography method. An overcoat film 28 is formed, an orientation control film 29 (AL1044 manufactured by Nippon Synthetic Rubber Co., Ltd.) is formed at a thickness of 0.07 μm, and is cured by applying heat in an oven at 180 ° C., followed by rubbing treatment. And the color filter substrate 101 is formed. Further, a sealant (not shown) made of an epoxy-based adhesive for bonding the two substrates is applied around the surface of the color filter substrate 101 where the orientation control film 29 is formed by a dispenser method.

Next, as shown in FIG. 1E, both the substrates are opposed and overlapped so that each pixel electrode region on the electrode substrate 100 and the color filter 27 of the color filter substrate 101 face each other. Thereafter, thermocompression bonding is performed in which a pressure of 0.5 kgf / cm ² is applied to the entire substrate, and the sealing material is cured while applying heat at 150 ° C. In this step, the sealing material is cured, the gap between the opposing substrates is made uniform by the spacer 30, and the functional groups present on the surface of the spacer 30 and the orientation control films 24 and 29 are combined to fix the spacer 30. Is done.
Thereafter, as shown in FIG. 1F, the liquid crystal 31 is injected into the gap between the substrates by a decompression method and sealed. In addition, there is a technique in which both substrates are pressurized after the liquid crystal is injected in the decompression method, and after the extra liquid crystal is discharged to the outside, sealing is performed. In this reference example, the alignment control films 24 and 29 may be disconnected. When this is done, it is confirmed that the bond between the spacer 30 and the alignment control films 24 and 29 is cut at a rate of 50% or more. Therefore, the liquid crystal was injected by the decompression method after the liquid crystal 31 reached the substrate end opposite to the injection part, and left for 1 hour, and sealed without applying pressure.

In the in-plane response type liquid crystal display device manufactured by the above process, since the spacer 30 having a functional group on the surface is bonded to the alignment control films 24 and 29, even if a physical impact is applied to the panel, The spacer 30 does not move, and the combined area is very small, so light leakage can be suppressed to a small level, and good display characteristics can be obtained without a decrease in contrast ratio and a rough impression on the display surface. It was.
Note that, depending on the combination of the uneven shape of the electrode substrate 100 and the color filter substrate 101, the size of the spacer 30, the strength of the pressure bonding, and the like, the spacer 30 is either the electrode substrate 100 or the color filter substrate 101 in the thermocompression bonding process. In this case, the spacer 30 can be prevented from moving, and the same effect can be obtained.

Reference Example 2
In this reference example, a spacer material capable of preventing light leakage caused by uniaxial alignment disturbance occurring around a conventional spacer will be described. The structure of the in-plane response type liquid crystal display device in the present reference example is the same as the structure described in the first reference example (FIG. 1) except that the spacer material is different, and the illustration is omitted.
The spacer in this reference example is made of a polymer compound having a large number of long-chain alkyl groups on the surface. This long chain alkyl group is bonded to a graft polymer chain by graft polymerization and has 6 or more carbon atoms. According to this reference example, since the alignment regulating force on the spacer surface is strong, it is possible to achieve a state in which no -axial alignment disorder occurs in the periphery of the spacer and no light leakage occurs.

  In the reference example 1, the spacer 30 is fixed to at least one of the electrode substrate 100 and the color filter substrate 101, thereby preventing light leakage due to the alignment control films 24 and 29 being damaged by the movement of the spacer 30. However, it was not possible to prevent light leakage due to the uniaxial alignment disorder generated around the spacer 30. On the other hand, according to this reference example, it is possible to prevent light leakage due to uniaxial alignment disorder generated around the spacer. That is, by combining the above Reference Example 1 and the present Reference Example, light leakage can be completely prevented, and there is no in-plane response type liquid crystal display with good display characteristics without a decrease in contrast ratio or a rough impression on the display surface. A device can be obtained.

Embodiment 1 FIG.
FIG. 2 is a cross-sectional view showing a manufacturing process of the in-plane response type liquid crystal display device according to the first embodiment of the present invention, and FIG. 3 is a cross-sectional view showing the in-plane response type liquid crystal display device produced in the present embodiment. is there. In the figure, 100a is an electrode substrate created in the present embodiment, 32 is a convex pattern locally formed on the source wiring 21, and 30a is a spacer. In the drawings, the same or corresponding parts are denoted by the same reference numerals, and description thereof is omitted.
In the present embodiment, a locally convex pattern 32 is formed below one or both of the gate wiring (not shown) and the source wiring 21 below the orientation control film 24 of the electrode substrate 100a. The gap between the electrode substrate 100a and the color filter substrate 101 is defined by the spacer 30a disposed on the convex pattern 32, and the alignment control film 24 and the color of the electrode substrate 100a are disposed on the spacer 30a disposed in the other region. In this arrangement, at least one of the orientation control films 29 of the filter substrate 101 is prevented from contacting. Note that the particle size accuracy distribution of a normal spacer is about 0.2 μm in standard deviation, and 0.6 μm when the σ value is applied as a process control standard. Therefore, the height of the convex pattern 32 is 0. The thickness was 6 μm or more.

A method for manufacturing the liquid crystal display device in this embodiment will be described with reference to FIGS. First, as shown in FIG. 2A, an electrode substrate 100a is manufactured by the same method as in Reference Example 1. Next, as shown in FIG. 2B, a convex pattern 32 of length × width × height 5 μm × 50 μm × 0.6 μm is formed on the source wiring 21 having a wiring width of 6 μm by photolithography. To do. The material of the convex pattern 32 may be a pigment, a material used for the electrode substrate 100a (SiN, SiO ₂ , Al, Cr) or the like, but considering the influence on liquid crystal driving, the pigment, SiN, SiO ₂ Insulating materials such as are desirable. In this case, considering the good contact with the base, 0.6 μm of SiN was laminated. Thereafter, as shown in FIG. 2C, an alignment control film 24 was formed, and the liquid crystal display device shown in FIG.

  The diameter of the spacer 30a used in the present embodiment is a pattern 32 that is more convex than the spacer 30 used in Reference Example 1 above when the thickness of the liquid crystal display device in Reference Example 1 is the same as that of the liquid crystal layer. The height is reduced by 0.6 μm. Therefore, a region other than the convex pattern 32, for example, the spacer 30a disposed in the pixel portion does not contact both the alignment control film 24 of the electrode substrate 100a and the alignment control film 29 of the color filter substrate 101. That is, since there is no light leakage due to scratches on the alignment control films 24 and 29 due to the movement of the spacer 30a, good display characteristics can be obtained without a decrease in contrast ratio or a rough impression on the display surface.

Embodiment 2. FIG.
FIG. 4 is a cross-sectional view showing the manufacturing process of the in-plane response type liquid crystal display device according to the second embodiment of the present invention, and FIG. 5 is a cross-sectional view showing the in-plane response type liquid crystal display device created in the present embodiment. is there. In the figure, 101a is a color filter substrate prepared in the present embodiment, 33 is a convex pattern locally formed on the light shielding film 26 of the color filter substrate 101a, and 30b is a spacer. In the drawings, the same or corresponding parts are denoted by the same reference numerals, and description thereof is omitted.
In the present embodiment, a locally convex pattern 33 is provided below the alignment control film 29 of the color filter substrate 101 a and on the light shielding film 26, and the electrode is formed by the spacer 30 b disposed on the convex pattern 33. A gap between the substrate 100 and the color filter substrate 101a is defined, and at least one of the alignment control film 24 of the electrode substrate 100 and the alignment control film 29 of the color filter substrate 101a is not in contact with the spacer 30b disposed in the other region. It is what I did. The height of the convex pattern 33 is set to 0.6 μm or more for the same reason as in the first embodiment.

A method for manufacturing the liquid crystal display device in this embodiment will be described with reference to FIGS. First, as shown in FIG. 4A, on a glass substrate 25, a light shielding film 26 made of a metal such as a pigment or chromium, a color filter 27 made of a pigment or a dye, and an overcoating made of an organic or inorganic material are formed by a photolithography method. The color filter substrate 101a provided with the film 28 is formed. Next, as shown in FIG. 4B, a convex pattern 33 of length × width × height 15 μm × 50 μm × 0.6 μm is formed on the light-shielding film 26 having a width of 25 μm by photolithography. Form. The material of the convex pattern 33 may be a pigment or a material used for an electrode substrate (SiN, SiO ₂ , Al, Cr) or the like, but considering the influence on liquid crystal driving, the pigment, SiN, SiO _2, etc. Insulating materials are desirable. In this embodiment, considering the good contact with the base, an acrylic resin that is the same material as the overcoat film 28 is laminated by 0.6 μm. Thereafter, as shown in FIG. 4C, an alignment control film 29 was formed, and the liquid crystal display device shown in FIG. 5 was completed by the same steps as in Reference Example 1.

  The diameter of the spacer 30b used in the present embodiment is a pattern 32 that is more convex than the spacer 30 used in Reference Example 1 above when the thickness of the liquid crystal display device in Reference Example 1 is the same as that of the liquid crystal layer. The height is reduced by 0.6 μm. Therefore, a region other than the convex pattern 32, for example, the spacer 30b disposed in the pixel portion does not contact both the alignment control film 24 of the electrode substrate 100a and the alignment control film 29 of the color filter substrate 101. That is, since there is no light leakage due to scratches on the alignment control films 24 and 29 due to the movement of the spacer 30b, good display characteristics can be obtained without a decrease in contrast ratio and a rough impression on the display surface.

The same effect can be obtained by combining the first embodiment and the present embodiment. That is, the light shielding film 26 is below the alignment control film 24 of the electrode substrate 100a, on one or both of the gate wiring and the source wiring 21, and below the alignment control film 29 of the color filter substrate 101a. On the top, locally convex patterns 32 and 33 are provided so as to overlap each other, and the spacer 30a (30b) disposed on the convex patterns 32 and 33 defines the gap between the electrode substrate and the color filter substrate, It is also possible to prevent at least one of the alignment control film 24 of the electrode substrate 100a and the alignment control film 29 of the color filter substrate 101a from coming into contact with the spacers 30a (30b) arranged in other regions. Also in this case, the total height of the convex patterns 32 and 33 provided on the electrode substrate 100a and the color filter substrate 101a is 0.6 μm or more, and is made of an insulating material such as pigment, SiN, or SiO _2. To do. Moreover, the structure arrange | positioned so that the position of the convex parts 32 and 33 provided in the electrode substrate 100a and the color filter substrate 101a may mutually differ may be sufficient.

Embodiment 3 FIG.
In the first embodiment and the second embodiment, locally convex patterns 32 and 33 are provided on the electrode substrate 100a or the color filter substrate 101a, and the spacers disposed on the convex patterns 32 and 33 are provided. The gap between the electrode substrate and the color filter substrate is defined by the above, and at least one of the alignment control film of the electrode substrate and the alignment control film of the color filter substrate is not in contact with the spacer disposed in the pixel region which is the other region. However, in the present embodiment, by setting the spacer diameter to be slightly smaller than the gap between the two substrates, the spacer may include at least one of the alignment control film of the electrode substrate and the alignment control film of the color filter substrate. Either one is not touched. The spacer has a diameter d satisfying Dd> 0.2 μm with respect to the gap D between the two substrates.
According to the present embodiment, since the spacer diameter is sufficiently small with respect to the gap D between the two substrates, the spacer is not sandwiched between the two substrates and the alignment control film is not damaged, and light leakage associated therewith is prevented. Can be prevented. Since the particle size accuracy distribution of a normal spacer is about 0.2 μm in standard deviation, the necessary difference between the gap between the substrates and the spacer diameter is 0.2 μm or more.

Embodiment 4 FIG.
In the present embodiment, in the liquid crystal injection process and the sealing process of the in-plane response type liquid crystal display element, the pressure inside the panel in which the liquid crystal is arranged is set to −0.3 kgf / cm ² or more with respect to the atmospheric pressure. Thus, the spacer is brought into contact with only one of the alignment control film of the electrode substrate and the alignment control film of the color filter substrate to suppress light leakage.
A method for manufacturing the liquid crystal display device in this embodiment will be described with reference to FIGS. In the figure, 34 is a sealing material formed at the outer edge between the substrates, part of which reaches the edge of the substrate to form a liquid crystal injection port 35, 36 is liquid crystal, and 37 is a container filled with liquid crystal 36. A liquid crystal storage tray, 38 is inside the panel, and 39 is a liquid crystal injector.
First, a spacer is arranged between an electrode substrate having a plurality of electrodes such as a gate wiring, a source wiring, and a pixel electrode and an alignment control film, and a color filter substrate having a color filter, a light shielding film and an alignment control film, and two sheets A panel is formed by bonding together with a sealing material 34 that is formed at the outer edge between the substrates and part of the substrate reaches the edge of the substrate to form a liquid crystal injection port.

Next, as shown in FIG. 6A, the panel is installed in a liquid crystal injector 39 in which a liquid crystal storage dish 37 filled with liquid crystal 36 is installed, and the liquid crystal injector 39 and the inside of the panel are installed. 38 is evacuated. Although depending on the mechanism and performance of the liquid crystal panel, it is desirable that the vacuum state is about 10 ⁻² torr in consideration of the remaining amount of air remaining in the panel interior 38. The shape and material of the liquid crystal injector 39 are not limited as long as the liquid crystal injector 39 has a size that can be sealed by a panel. In FIG. 6, the number of liquid crystal injection holes 35 is one, but it is sufficient that one or more liquid crystal injection holes 35 are formed on one side.
Next, as shown in FIG. 6B, after the inside of the liquid crystal injector 39 including the panel interior 38 is in a uniform vacuum state, the injection port 35 is attached to the liquid crystal 36. As a result, the panel interior 38 is covered with the liquid crystal 36. Thereafter, as shown in FIG. 6 (c), the liquid crystal injector 39 is returned to the atmospheric pressure (760 torr) with the injection port 35 immersed in the liquid crystal 36 in the liquid crystal storage dish 37, and the liquid crystal 36 is injected by the pressure difference. After filling the inside of the panel 38 from the inlet 35, the panel is left for a predetermined time, and pressure from the outside is not applied to the panel, and the spacer is either the alignment control film of the electrode substrate or the alignment control film of the color filter substrate. The inlet is sealed in contact with only one side. In the present embodiment, after filling, the injection port 35 is sealed by leaving it for 120 minutes or longer. At this time, the pressure inside the panel in which the liquid crystal is arranged is −0.3 kgf / cm ² or more with respect to the atmospheric pressure, and the pressure from the outside is slightly applied. If so, a state in which no light leakage is observed is obtained. That is, the predetermined time is a time during which the pressure inside the panel becomes −0.3 kgf / cm ² or more with respect to the atmospheric pressure.

  In general, in the method of injecting liquid crystal using a differential pressure from the atmospheric pressure as described above, the liquid crystal 36 is filled in the panel interior 38 when the atmospheric pressure and the internal pressure of the liquid crystal display panel become equal. In FIG. 6C, when the liquid crystal 36 is filled into the panel interior 38 from the inlet 35, the panel interior 38 is in a state of being pressurized at atmospheric pressure. Therefore, the gap between the two substrates is very narrow. In this state, the liquid crystal 36 enters the inside due to the pressure difference between the panel interior 38 and the atmospheric pressure and the capillary phenomenon. When the liquid crystal 36 reaches the seal 34 on the opposite side of the inlet 35, the liquid crystal injection on the appearance is completed, but when the liquid crystal 36 reaches the seal 34, the internal pressure of the panel is in a negative pressure state. From this state, the transition in which the panel interior 38 balances with the atmospheric pressure is called relaxation time.

  FIG. 7 shows the relationship between the relaxation time and the gap (panel gap) between the two substrates facing each other. The liquid crystal display device in FIG. 7 is an in-plane response type liquid crystal display device having a diagonal size of 10.4 ”S-VGA, and the main constituent members are plastic spacers having a spherical diameter of 3.2 μm on spacers scattered in the display surface. (Sekisui Fine Chemical Co., Ltd .; Micropearl SP-2032), an alignment control film (Nippon Synthetic Rubber Co., Ltd .; Optomer AL1044) is formed on both sides of the substrate facing 0.06 μm, and a sealing material that bonds the two substrates together (Mitsui Chemicals) Company: Structbond XN-21S) mixed with glass spacer (Nippon Denki Glass Co., Ltd .; Microlot PF-45) and used a liquid crystal material with a viscosity of 20 cp for in-plane response type liquid crystal display devices. The inlet is 24 mm wide, and the relationship between the relaxation time and the panel gap under the same conditions is saturated when left for about 200 minutes. The time was 210 minutes, that is, it took 410 minutes to complete the liquid crystal injection, and the filling time of the liquid crystal increased in proportion to the size of the liquid crystal display element, so that the production of the large element was completed. As the amount increases, the manufacturing facility is under pressure, so in the manufacturing process of the conventional TN liquid crystal display device, the sealing process is performed when the required panel gap and liquid crystal layer uniformity are satisfied. It was common to move and secure production.

However, in the case of the in-plane response type liquid crystal display device, it is necessary to strictly manage the above process as compared with the TN method. If the relaxation time is shortened in the liquid crystal injection process, the amount of liquid crystal filled in the panel is reduced. As a result, the spacer existing in the display surface is sandwiched between two substrates disposed opposite to each other, resulting in a light-exiting region in the periphery of the spacer. For example, in the case of FIG. 7, a light-out region around the spacer occurs at a relaxation time of 100 minutes, and does not occur after 120 minutes. That is, it is considered that the spacer is in contact with both orientation control films of the two substrates arranged opposite to each other at a relaxation time of 100 minutes, and is in contact with only one side at 120 minutes. When the internal pressure in the liquid crystal panel at the relaxation time of 120 minutes is calculated from the state of the panel gap, it is in a state of −0.28 kgf / cm ² with respect to the atmospheric pressure. Since the state where no light leakage occurs is between the relaxation times of 100 to 120 minutes, the pressure in the in-plane response type liquid crystal display device can be managed to be −0.3 kgf / cm ² or more. is necessary.

  In addition, the kind of liquid crystal material used in the first to fourth embodiments is not particularly limited, and a liquid crystal material used in a normal TN liquid crystal display device can be used. The value of the dielectric anisotropy of the liquid crystal material is not particularly limited, but is preferably in the range of 1 ≦ Δε ≦ 12. When the dielectric anisotropy of the liquid crystal material is Δε <1, the responsiveness to the electric field is low, and thus a high voltage is required for driving. In the case of Δε> 12, since the polarization of the liquid crystal material is large, impurities such as ionic impurities are easily included, and the liquid crystal material is likely to be deteriorated. The product of the refractive index anisotropy (Δn) of the liquid crystal material and the panel gap (d), the value of Δn · d is not particularly limited, but is preferably 0.1 μm or more and 0.4 μm or less. Although the display can be performed even when the thickness is less than 0.1 μm or exceeds 0.4 μm, there are cases where the coloration is large and good color reproducibility cannot be obtained.

  In addition, the type of liquid crystal alignment control film that can be used in the first to fourth embodiments is not particularly limited, and it is possible to use a soluble polyimide, an amic acid baking type polyimide, or the like used in a normal liquid crystal display device. it can. The size of the pretilt angle is not particularly limited, but is preferably 10 degrees or less. When the angle exceeds 10 degrees, the angle dependency of the viewing angle is large, and the excellent viewing angle characteristic that is a feature of the in-plane response type liquid crystal display device may not be obtained.

  The present invention can be used for an in-plane response type liquid crystal display device used as a display element of a personal computer or the like.

It is sectional drawing which shows the manufacturing process of the in-plane response type liquid crystal display device in the reference example 1 of this invention. It is sectional drawing which shows the manufacturing process of the in-plane response type liquid crystal display device in Embodiment 1 of this invention. It is sectional drawing which shows the in-plane response type liquid crystal display device in Embodiment 1 of this invention. It is sectional drawing which shows the manufacturing process of the in-plane response type liquid crystal display device in Embodiment 2 of this invention. It is sectional drawing which shows the in-plane response type liquid crystal display device in Embodiment 2 of this invention. It is explanatory drawing which shows the manufacturing method of the in-plane response type liquid crystal display device in Embodiment 4 of this invention. It is a figure which shows the relationship between the panel gap | interval and relaxation time of a liquid crystal display device. It is a schematic diagram which shows the structure of a general in-plane response type liquid crystal display device. In the conventional in-plane response type liquid crystal display device, it is a figure explaining the light omission by the disorder of the uniaxial liquid crystal alignment which generate | occur | produces in the spacer vicinity. In the conventional in-plane response type liquid crystal display device, it is a diagram for explaining light leakage due to disorder of liquid crystal alignment that occurs when the spacer damages the surface of the alignment control film.

Explanation of symbols

1a, 1b comb type electrode, 2 liquid crystal molecules, 3 electrode substrate, 4 counter substrate,
5 equipotential lines, 6 incident light, 7, 8 polarizing plate, 9 outgoing transmitted light,
10 alignment direction of liquid crystal, 11, 13, 16, 17 portions where liquid crystal alignment is disturbed,
12 spacer, 14, 15 orientation control film, 20 glass substrate,
21 source wiring, 22 gate insulating film, 23 pixel electrode,
24 orientation control film, 25 glass substrate, 26 light shielding film,
27 color filter, 28 overcoat film, 29 orientation control film,
30, 30a, 30b spacer, 31 liquid crystal,
32, 33 Convex pattern, 34 Sealant, 35 Inlet, 36 Liquid crystal,
37 Liquid crystal storage tray, 38 Inside panel, 39 Liquid crystal injector, 40 rollers,
100, 100a Electrode substrate, 101, 101a Color filter substrate.

Claims (10)

A first substrate having a plurality of electrodes such as a scanning signal line, a video signal line, and a pixel electrode, and a second substrate having a color filter, a light-shielding film, and the like and arranged to face the first substrate with a certain distance therebetween. A substrate, an alignment control film provided on each of the opposing surfaces of the two substrates, a spacer that defines a gap between the two substrates, and a liquid crystal disposed between the two substrates, In a liquid crystal display device in which a voltage is applied between the electrodes to generate an electric field substantially parallel to the substrate surface and the liquid crystal molecules respond in-plane,
A convex pattern is locally provided below the alignment control film on the first substrate and on one or both of the scanning signal line and the video signal line, and the convex pattern. A gap between the first substrate and the second substrate is defined by the spacer disposed above, and the alignment control film and the second substrate on the first substrate are disposed on the spacer disposed in another region. A liquid crystal display device characterized in that at least one of the alignment control films on the substrate is not in contact. A first substrate having a plurality of electrodes such as a scanning signal line, a video signal line, and a pixel electrode, and a second substrate having a color filter, a light-shielding film, and the like and arranged to face the first substrate with a certain distance therebetween. A substrate, an alignment control film provided on each of the opposing surfaces of the two substrates, a spacer that defines a gap between the two substrates, and a liquid crystal disposed between the two substrates, In a liquid crystal display device in which a voltage is applied between the electrodes to generate an electric field substantially parallel to the substrate surface and the liquid crystal molecules respond in-plane,
A locally convex pattern is provided below the alignment control film of the second substrate and on the light shielding film, and the first substrate and the above are provided by the spacers disposed on the convex pattern. At least one of the alignment control film of the first substrate and the alignment control film of the second substrate does not contact the spacers that define the gap of the second substrate and are disposed in other regions. A liquid crystal display device characterized by that. The liquid crystal display device according to claim 1, wherein the convex pattern has a height of 0.6 μm or more. A first substrate having a plurality of electrodes such as a scanning signal line, a video signal line, and a pixel electrode, and a second substrate having a color filter, a light-shielding film, and the like and arranged to face the first substrate with a certain distance therebetween. A substrate, an alignment control film provided on each of the opposing surfaces of the two substrates, a spacer that defines a gap between the two substrates, and a liquid crystal disposed between the two substrates, In a liquid crystal display device in which a voltage is applied between the electrodes to generate an electric field substantially parallel to the substrate surface and the liquid crystal molecules respond in-plane,
Below the orientation control film on the first substrate, on one or both of the scanning signal lines and the video signal lines, and below the orientation control film on the second substrate. A locally convex pattern is provided on the light-shielding film so as to overlap with each other, and a gap between the first substrate and the second substrate is defined by the spacer disposed on the convex pattern. The liquid crystal is characterized in that at least one of the alignment control film of the first substrate and the alignment control film of the second substrate is not in contact with the spacer disposed in the other region. Display device. 5. The liquid crystal display device according to claim 4, wherein the convex patterns provided on the first substrate and the second substrate have a total height of 0.6 [mu] m or more. The liquid crystal display device according to claim 1, wherein the convex pattern is made of an insulating material such as pigment, SiN, or SiO ₂ . A first substrate having a plurality of electrodes such as a scanning signal line, a video signal line, and a pixel electrode, and a second substrate having a color filter, a light-shielding film, and the like and arranged to face the first substrate with a certain distance therebetween. A substrate, an alignment control film provided on each of the opposing surfaces of the two substrates, a spacer that defines a gap between the two substrates, and a liquid crystal disposed between the two substrates, In a liquid crystal display device in which a voltage is applied between the electrodes to generate an electric field substantially parallel to the substrate surface and the liquid crystal molecules respond in-plane,
The spacer has a diameter d slightly smaller than the gap D between the two substrates and D−d> 0.2 μm. The spacer includes the alignment control film on the first substrate and the spacer. A liquid crystal display device characterized in that at least one of the alignment control films on the second substrate does not contact. A first substrate having a plurality of electrodes such as a scanning signal line, a video signal line, and a pixel electrode, and a second substrate having a color filter, a light-shielding film, and the like and arranged to face the first substrate with a certain distance therebetween. A substrate, an alignment control film provided on each of the opposing surfaces of the two substrates, a spacer that defines a gap between the two substrates, and a liquid crystal disposed between the two substrates, In a liquid crystal display device in which a voltage is applied between the electrodes to generate an electric field substantially parallel to the substrate surface and the liquid crystal molecules respond in-plane,
The internal pressure where the liquid crystal is arranged is −0.3 kgf / cm ² or more with respect to atmospheric pressure, and the alignment control film of the first substrate and the alignment control of the second substrate are used as the spacer. A liquid crystal display device characterized in that at least one of the films is not in contact. A spacer is arranged between a first substrate having a plurality of electrodes such as scanning signal lines, video signal lines, pixel electrodes and an alignment control film, and a second substrate having a color filter, a light shielding film and an alignment control film, A step of forming a panel by bonding together with a sealing material that is formed at the outer edge portion between the two substrates and a part of the substrate reaches the end of the substrate to form a liquid crystal injection port;
Installing the panel in a liquid crystal injector in which a container filled with liquid crystal is installed, and evacuating the liquid crystal injector and the panel;
The liquid crystal injector is returned to atmospheric pressure in a state where the injection port is immersed in the liquid crystal in the container, and after the liquid crystal is filled into the panel from the injection port by a pressure difference, the liquid crystal injector is further left for a predetermined time, And a step of sealing the injection port in a state where at least one of the alignment control film of the first substrate and the alignment control film of the second substrate is not in contact with the spacer. Device manufacturing method. 10. The method for manufacturing a liquid crystal display device according to claim 9, wherein the predetermined time is a time during which the pressure inside the panel is −0.3 kgf / cm ² or more with respect to atmospheric pressure.

Images