JP2000019527A - Liquid crystal display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress the lowering of brightness and contrast by preventing the lowering of brightness due to contamination of liquid crystal caused by columnar spacers and the generation of an electric short-circuit between substrates. SOLUTION: This device is equipped with polarizing plates POL1, POL2 and a driving means for applying a driving voltage to a group of electrodes. The device is provided with the arrayed structure of the electrodes arranged as the group of electrodes applies a primarily parallel voltage to boundaries between orientation controlling layers ORI1, ORI2 and a liquid crystal layer LC and columnar spacers SP formed by patterning of an overcoat layer OC film-formed on the upper layer of black matrices BM an color filters FIL and under the lower layer of the orientation controlling layer ORI2. In this case, the base part and the top part of the columnar spacer SP have about the same area, its cross-section in the direction in parallel to the plane of substrates has an acute angle shape to the direction of rubbing and the top part of the orientation controlling layer ORI2 film-formed on the upper layer of the columnar spacer SP is brought in contact with the orientation controlling layer ORI1 of the other substrate SUB1.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid crystal display device, and more particularly, to a so-called in-plane switching method provided with a spacer having a novel structure for keeping a distance between a pair of substrates for sealing a liquid crystal composition constant. Liquid crystal display device.

[0002]

2. Description of the Related Art A liquid crystal display device has been widely used as a display device capable of displaying a high-definition color image for a notebook computer or a computer monitor.

This type of liquid crystal display device basically constitutes a so-called liquid crystal panel in which a liquid crystal composition is sandwiched between at least two substrates made of transparent glass or the like at opposing gaps. A type (simple matrix type liquid crystal display device) in which a predetermined pixel is turned on and off by selectively applying a voltage to various electrodes for pixel formation formed on the substrate, and the above-mentioned various electrodes and an active element for pixel selection are formed. The active matrix type is broadly classified into a type in which predetermined pixels are turned on and off by selecting the active element (active matrix type liquid crystal display device).

An active matrix type liquid crystal display device is
Thin film transistor (TFT) as its active element
Is typical. 2. Description of the Related Art A liquid crystal display device using a thin film transistor is widely used as a monitor for a display terminal of OA equipment because it is thin and lightweight and has high image quality comparable to a cathode ray tube.

[0005] The display methods of this liquid crystal display device are roughly classified into the following two types based on the difference in the method of driving the liquid crystal. Part 1
First, the liquid crystal composition is sandwiched between two substrates each having a transparent electrode, operated by a voltage applied to the transparent electrode, and light transmitted through the transparent electrode and incident on the liquid crystal composition layer is modulated for display. Most of the products currently in wide use adopt this method.

The other is to operate by an electric field formed almost parallel to the substrate surface between two electrodes formed on the same substrate, and to make light incident on a layer of the liquid crystal composition from a gap between the two electrodes. Is modulated and displayed, and has a feature that a viewing angle is extremely wide, and is a very promising method as an active matrix liquid crystal display device. Regarding the features of this method, for example, Japanese Patent Publication No. 5-505247,
JP-B-63-21907, JP-A-6-16087
No. 8 and other publications. Hereinafter, this type of liquid crystal display device is referred to as a horizontal electric field type liquid crystal display device.

The distance between a pair of substrates (the thickness of the liquid crystal composition layer: cell gap) is generally set to a predetermined value by dispersing spherical spacers (not shown) between the two substrates. It is. A polarizing plate is provided on the outer surface of each substrate, and a so-called normally black display mode can be achieved by arranging the polarizing axes of the polarizing plates at right angles.

In addition, instead of the spherical spacer as described above, a conical or polygonal pyramid spacer is fixedly formed on the protective film of the color filter substrate on the substrate, or a columnar shape is formed by laminating a color filter layer. A fixed spacer is disclosed in Japanese Patent Application Laid-Open No. 9-73088. However, the invention disclosed in this publication specifies the shape and arrangement only from the viewpoint of reducing the effect of rubbing defects caused by the bristle of the rubbing cloth being disturbed by the spacer, and the invention is based on the formation of the spacer. This is different from the object of the present invention to reduce a decrease in luminance and contrast due to a difference in thickness of the liquid crystal layer near the spacer from other portions.

FIG. 8 is a sectional view of an essential part for explaining an example of the configuration of a conventional in-plane switching type liquid crystal display device in which a spacer is formed by overlapping colored layers. This liquid crystal display device has one substrate S
Video signal line DL, counter electrode CT, pixel electrode P on UB1
X is formed, and a protective film PSV is formed on these layers.
And a coloring layer (color filter) FIL having an alignment control layer ORI1 formed at an interface with a layer of a liquid crystal composition (hereinafter, also simply referred to as liquid crystal) LC, and partitioned by a black matrix BM on the other substrate SUB2. The overcoat layer OC was formed so as to cover these upper layers so that the components of the color filter FIL and the black matrix BM did not affect the liquid crystal composition LC, and was formed at the interface with the liquid crystal LC layer. It has an orientation control layer ORI2.

The GI on one substrate SUB1
And AOF are insulating films, and the video signal lines DL are conductive films d1 and d2.
The counter electrode CT is made of a conductive film g1, and the pixel electrode PX is made of a conductive film g2. The liquid crystal L is applied with an electric field substantially parallel to the substrate formed between the pixel electrode PX and the counter electrode CT.
An image is displayed by controlling the orientation direction of the C molecule.

[0011]

In the case where the conical or polygonal pyramid-shaped spacer is provided, the cross-sectional shape of the columnar spacer SP in the direction perpendicular to the substrate has a tapered shape in which the bottom is large and the top is small. Becomes Therefore, the thickness of the liquid crystal layer LC around the columnar spacer SP is smaller than the thickness of the central part of the pixel. Therefore, the thickness of the liquid crystal layer LC becomes non-uniform in the display area, which causes a decrease in brightness and contrast. When the area at the bottom of the columnar spacer SP is reduced, the area at the top is also reduced. At this time, if the mechanical strength of the columnar spacer SP is large, the columnar spacer SP may break the insulating layer of the other substrate and reach a conductive layer such as an electrode. In addition, the liquid crystal is contaminated by the destruction of the insulating layer, which causes a decrease in luminance.

Similarly, the adjacent color filters FIL described with reference to FIG. 8 are overlapped on the upper layer of the black matrix BM to increase the thickness, and the columnar spacer SP is formed in the shape of a protrusion of the overcoat layer OC formed thereon. Also, the cross-sectional shape of the columnar spacer SP in the direction perpendicular to the substrate is tapered such that the bottom portion is large and the top portion is small due to the overcoat layer OC formed on the color filter FIL. The resolution of such a columnar spacer SP is limited by its constituent materials and manufacturing processability, and its bottom may reach the display region (pixel portion) in some cases.

For this reason, the thickness dLC1 of the liquid crystal layer LC around the columnar spacer SP is smaller than the thickness dLC2 of the central part of the pixel. Therefore, in the display area, the liquid crystal layer LC
Has a non-uniform thickness, which causes a decrease in brightness and contrast. When the area at the bottom of the columnar spacer SP is reduced, the area at the top is also reduced. At this time, the columnar spacer S
If the mechanical strength of P is large, the columnar spacer SP may break the insulating layer of the other substrate and reach a conductive layer such as an electrode. In addition, the liquid crystal is contaminated by the destruction of the insulating layer, which causes a decrease in luminance. Further, when a transparent conductive layer such as ITO is formed also on the top of the columnar spacer SP as described in JP-A-9-73088, an electrical short circuit occurs between the substrates, resulting in display failure. There is.

On the other hand, if the mechanical strength of the columnar spacer SP is low, the columnar spacer SP is broken, and the liquid crystal layer LS
Has a problem that the thickness (cell gap) becomes uneven and display unevenness is caused.

The shape of the columnar spacer SP can be formed on the top of the color filter shown in FIG.
As described in Japanese Patent Publication No. 73088, a conical or polygonal pyramid shape is used. In a shape in which a portion of the rubbing cloth to which the bristle touches becomes a top portion and has a taper, a columnar shape in contact with a substrate on which a columnar spacer is not formed. The area of the spacer SP becomes extremely small, which causes a decrease in luminance due to contamination of liquid crystal, a display failure due to an electrical short circuit between the substrates, and an uneven display due to an uneven thickness of the liquid crystal layer for the same reason as described above. There is a problem.

An object of the present invention is to prevent a decrease in luminance due to liquid crystal contamination caused by columnar spacers, prevent an electric short circuit between substrates, and suppress a decrease in luminance and contrast, thereby preventing display unevenness. It is to provide a liquid crystal display device.

[0017]

SUMMARY OF THE INVENTION The present invention eliminates alignment defects caused by columnar spacers in the rubbing treatment of an alignment film, eliminates unevenness in the thickness of the liquid crystal layer around the columnar spacers, and further reduces the thickness of the columnar spacers. In order to prevent the insulation layer and the like formed on the opposing substrate from being destroyed to cause liquid crystal contamination and to prevent the occurrence of an electric short circuit between the substrates, the following means is employed.

In order to eliminate problems such as poor orientation in the rubbing process, the side where the rubbing cloth of the columnar spacer first contacts is the front side, and the side where the rubbing cloth flows is the rear side. The shape becomes an acute angle to the rubbing direction. Accordingly, the resistance applied to the rubbing cloth by the front side of the columnar spacer is reduced, and the bristle of the rubbing cloth is easily restored to the original state along the shape of the columnar spacer behind the columnar spacer. Therefore, the rubbing cloth is less likely to be damaged by the columnar spacer, and required rubbing is also easily performed on the rear portion of the columnar spacer.

Further, by forming the columnar spacer so that the area of the bottom side and the area of the top are the same, the pressure applied to the opposing substrate by the top of the columnar spacer is reduced, and the insulating layer and the protective film of the opposing substrate are damaged. And contamination of the liquid crystal is prevented.

Since no transparent conductive film such as ITO is formed on the columnar spacer, only the columnar spacer, which is an insulator, comes into contact with the opposing substrate, and no electrical short circuit occurs between the substrates. . That is, it is preferable to apply the present invention to a horizontal electric field type liquid crystal display device in which all the electrode groups for driving liquid crystal are formed on the active matrix substrate side.

That is, in order to achieve the above object, the present invention is characterized in having the following configuration.

(1) A pair of substrates, at least one of which is transparent, at least two or more types of color filters having different colors for color display formed on one of the pair of substrates, and interposed between the color filters. A black matrix, an electrode group including a signal wiring and a counter wiring formed on the other of the pair of substrates, and a liquid crystal composition having a dielectric anisotropy between the pair of substrates. A liquid crystal panel having a layer and an alignment control layer for arranging the molecular arrangement of the layer of the liquid crystal composition in a predetermined direction, a polarizing plate laminated on each of the pair of substrates with a polarization axis orthogonal to each other, and A driving unit for applying a driving voltage to the electrode group, wherein the electrode group applies a voltage mainly parallel to an interface between the alignment control layer and the liquid crystal composition layer. A columnar spacer formed by patterning an organic film formed on an upper layer of the black matrix and the color filter and a lower layer of the alignment control layer on at least one of the pair of substrates; The columnar spacer has the same area at the bottom and top, and the cross section in the direction parallel to the substrate surface has an acute angle with respect to the rubbing direction, and is formed on the columnar spacer. The top of the orientation control layer is in contact with the orientation control layer of the other substrate.

It should be noted that the acute angle of the cross section of the columnar spacer in the above configuration with respect to the rubbing direction does not mean only a completely acute angle. That is, in the process of forming the columnar spacer, the corner is usually rounded, and the acute angle means that the intersection of the tangent lines is an acute angle.

With this configuration, it is possible to obtain a liquid crystal display device of high display quality which eliminates non-uniformity of the thickness of the liquid crystal layer and does not decrease luminance and contrast.

(2) The method according to (1), wherein the columnar spacer is formed by patterning an organic film formed above the black matrix and the color filter and below the orientation control layer.

(3) The liquid crystal composition according to (1), wherein the columnar spacer has a dielectric property or a conductivity property higher than that of the liquid crystal composition.

According to the above configurations (2) and (3), an unnecessary electric field is not formed in the display area, and crosstalk is suppressed.
A liquid crystal display device with high display quality can be obtained.

[0028]

Embodiments of the present invention will be described below in detail with reference to the accompanying drawings. FIG. 1 is a plan view of an essential part for explaining a configuration near one pixel of a liquid crystal panel constituting a lateral electric field type active matrix type liquid crystal display device which is a first embodiment of a liquid crystal display device according to the present invention, and FIG. FIG. 2 is a sectional view taken along line 1-1 ′ of FIG.

In FIG. 2, a pair of substrates SUB1 and SU
Various electrodes and structural films disposed between B2 are the same as those in FIG. 8 except for the columnar spacer SP.

In FIGS. 1 and 2, DL is a video signal line,
SD2 is a drain electrode extending from the video signal line, CL is a counter voltage signal line, CT is a counter electrode same as the counter voltage signal line, PX is a pixel electrode, SD1 is a source electrode same as the pixel electrode, Cstg is a storage capacitor, GL Denotes a scanning signal line, GT denotes the same gate electrode as the scanning electrode, BM denotes a black matrix (indicated by a boundary line of a pixel opening), TFT denotes a thin film transistor, and SP denotes a columnar spacer.

As shown in FIG. 1, one columnar spacer SP is formed immediately below the black matrix BM in the area of the video signal line DL. However, the present invention is not limited to this. One or more may be formed at any place other than (part). Further, in this embodiment, the columnar spacers SP are formed on the color filter substrate side, but may be formed on the active matrix substrate side.

In this liquid crystal display device, an electrode group for applying an electric field substantially parallel to the substrate to the liquid crystal layer LC is formed on the active matrix substrate side. The columnar spacer SP is composed of a color filter FIL and a black matrix BM.
Is formed by patterning an overcoat layer OC covering the same, and an alignment control layer ORI2 is formed on the surface of the overcoat layer OC in the same manner as the pixel portion.

The orientation control layer ORI2 on the top of the columnar spacer SP contacts the orientation control layer ORI1 formed on the active matrix substrate to regulate the thickness of the liquid crystal layer LC.

FIG. 3 is a schematic perspective view for explaining an example of the shape of the columnar spacer in this embodiment. The front side and the rear side in the rubbing direction of a cross section parallel to the substrate form an acute angle.
And the edge is rounded. This is the columnar spacer S
In the exposure and development processes that are the process of forming P,
This is because it is difficult to form an angular shape due to light diffusion, diffraction, and the like, and it goes without saying that an angular shape may be used if it can be created.

It should be noted that the shape of the columnar spacer SP is not limited to a rhombic cross section as shown in FIGS.
The shape may be a substantially elliptical shape or a substantially oval shape having acute angles on the front side and the rear side in the rubbing direction.

According to this embodiment, a decrease in luminance due to liquid crystal contamination caused by the columnar spacer is prevented, an electrical short circuit between the substrates is prevented, and a decrease in luminance and contrast is suppressed. A liquid crystal display device can be provided.

In this embodiment, the number of columnar spacers SP per pixel is one as shown in FIG.
As described above, this number is not limited to one.
Also, a plurality may be arranged regularly, in a staggered manner, or randomly. If the dielectric constant or the conductivity characteristic of the columnar spacer SP is higher than that of the liquid crystal LC, an electric field is more easily formed on the columnar spacer SP than in the liquid crystal LC. Accordingly, the electric field between these electrodes causes the liquid crystal LC
Becomes difficult to be driven. For this reason, even in a portion where there is no columnar spacer SP, light is easily shielded in the normally black display mode. Therefore, it is desirable that the dielectric properties or conductivity properties of the columnar spacer be higher than those of the liquid crystal composition.

According to the present embodiment, the bottom and top of the columnar spacer have substantially the same area, so that the thickness of the liquid crystal layer as described in FIG. 8 is smaller in the vicinity of the columnar spacer than in the display area. Such non-uniformity is avoided, and the occurrence of display unevenness can be suppressed.

As described above, the thickness of the liquid crystal LC can be controlled by the columnar spacers, and it is not necessary to use generally used spherical spacers (plastic beads). Therefore, it is possible to prevent a decrease in contrast due to light leakage from the periphery of the spacer, which is likely to occur in the spherical spacer, a display failure when the spacers are unevenly arranged, and an alignment failure in the rubbing process.

Next, the outline of the manufacturing process of the liquid crystal display device of each of the above embodiments will be described.

First, in the same manner as in the known process for forming a thin film transistor, a thin film transistor made of amorphous silicon AS is formed by repeating film formation and patterning on a glass substrate having a thickness of 0.7 mm or 1.1 mm as one substrate SUB1. , A plurality of video signal lines DL for applying a predetermined voltage to the electrode group via a thin-film transistor TFT, and a plurality of video signal lines DL and a drain electrode SD2. A plurality of scanning signal lines GL for controlling conduction of the voltage signal lines CL and the thin film transistors TFT
And the gate electrode GT are formed in a lattice shape to form an active matrix substrate.

The thin film transistor TFT, each electrode group and each wiring are covered with an insulating film GI and a protective film PSV. Thereafter, an alignment film material is applied and baked, and a liquid crystal alignment control ability is imparted by a rubbing treatment to obtain an alignment control layer ORI1.

The other substrate SUB2 has a thickness of 0.1 mm.
A photosensitive black resist is applied to a 7 mm or 1.1 mm glass substrate, and a black matrix is formed through exposure, development, and baking steps using a photomask having a predetermined pattern. Next, using the photosensitive red, green, and blue resin resists, the same exposure, development, and baking steps as described above are repeated to form a red colored layer (color filter layer) FIL (FIL (R), FIL (G), FIL
(B)) is formed.

A transparent ultraviolet-curable resin resist is applied on the entire surface of the color filter layer, and a position where the spacer SP is to be formed is irradiated with ultraviolet rays through a photomask having a desired pattern and developed. At this time, the developing time is stopped at a time during which the non-photosensitive portion is not removed, and baking is performed to form the protective film OC covering the black matrix BM and the color filter layer FIL and the columnar spacer SP.

Since the top (the tip on the SUB1 side) of the columnar spacer SP is substantially flat, the columnar spacer SP does not have a gradual forward taper, and has a character-like columnar spacer SP whose bottom and top have substantially the same area. Become. Further, the black matrix BM and the coloring layer (color filter) F
After the formation of the IL, a transparent UV-curable resin resist is applied and baked to cover the entire surface with the protective film OC, and the transparent UV-curable resin resist is applied again to form a desired pattern at a position where the spacer SP is to be formed. The column spacers SP can also be obtained by irradiating ultraviolet rays through a photomask having the developed, baked, and baked. Thereafter, an alignment film material is applied to the color filter substrate and fired to obtain an alignment film ORI2 having a liquid crystal alignment control ability.

As described above, the columnar spacers SP may be formed on the active matrix substrate (SUB1) side. In this case, a transparent ultraviolet-curable resin resist is applied on the insulating film PSV of the active matrix substrate, and ultraviolet rays are irradiated to a position where the spacer SP is to be formed through a photomask having a desired pattern,
The columnar spacer SP is also obtained by developing and baking. In addition, the protective film PSV is deposited by the height of the columnar spacer SP, a resin resist for patterning is applied, and the position where the columnar spacer SP is to be formed is irradiated with ultraviolet rays through a photomask having a desired pattern to perform patterning. By etching the protective film PSV by dry etching and controlling the etching time, the columnar spacer SP and the protective film PSV can be simultaneously formed.

The active matrix substrate and the color filter substrate manufactured as described above are opposed to each other, the periphery thereof is fixed with an adhesive leaving a liquid crystal filling port, and a liquid crystal composition is sealed between the two substrates. The liquid crystal filling port is sealed with a sealing material. Thereafter, the distance between the two substrates is regulated by a columnar spacer by pressing to obtain a liquid crystal display device having a predetermined cell gap. According to the liquid crystal display device formed in this way, since the stress on the rubbing cloth is small and the restoring force of the nap of the rubbing cloth is also high, the occurrence of uneven display due to the rubbing defect is suppressed, and the contamination of the liquid crystal and between the substrates are prevented. An electrical short circuit is also prevented, and a liquid crystal display device with high reliability and high display quality can be obtained.

Next, the driving means of the liquid crystal display device to which the present invention is applied and specific examples of products will be described.

FIG. 4 is a schematic explanatory view of a driving means of a liquid crystal display device to which the present invention is applied. The liquid crystal display device is constituted by a set of a plurality of pixels in which an image display section is arranged in a matrix. Is configured to independently control the modulation of transmitted light from a backlight (not shown) arranged at the back of the liquid crystal display device.

On the active matrix substrate (SUB1), which is one of the components of the liquid crystal display substrate, the active pixel region AR extends in the x direction (row direction) and is juxtaposed in the y direction (column direction). The scanning signal lines GL and the counter voltage signal lines CL are insulated from each other, and extend in the y direction, and video signal lines DL arranged in parallel in the x direction are formed.

Here, a unit pixel is formed in a rectangular area surrounded by each of the scanning signal line GL, the counter voltage signal line CL, and the video signal line DL.

The liquid crystal display device is provided with a vertical scanning circuit V and a video signal driving circuit H as its external circuits, and the vertical scanning circuit V sequentially supplies a scanning signal (voltage) to each of the scanning signal lines GL. The video signal drive circuit H supplies a video signal (voltage) to the video signal line DL in accordance with the timing.

The vertical scanning circuit V and the video signal drive circuit H are supplied with power from the liquid crystal drive power supply circuit 3 and input image information from the CPU 1 after being divided into display data and control signals by the controller 2 respectively. It is supposed to be.

FIG. 5 is an explanatory diagram of an example of a driving waveform of a liquid crystal display device to which the present invention is applied. In FIG.
A binary AC rectangular wave of CH and VCL is formed, and in synchronism therewith, the non-selection voltages of the scanning signals VG (i-1) and VG (i) are changed by binary values of VCH and VCL every scanning period.
The amplitude width of the counter voltage and the amplitude value of the non-selection voltage are the same.

The video signal voltage is a voltage obtained by subtracting half the amplitude of the counter voltage from the voltage to be applied to the liquid crystal layer.

The counter voltage may be DC, but by converting it to AC, the maximum amplitude of the video signal voltage can be reduced, and a video signal drive circuit (signal side driver) having a low withstand voltage can be used.

FIG. 6 is an exploded perspective view for explaining the entire structure of the liquid crystal display device according to the present invention.
A liquid crystal display module in which two substrates SUB1 and SUB2 are bonded to each other, a driving unit, a backlight, and a liquid crystal display module (hereinafter, referred to as an MDL) in which other components are integrated is described.

SHD is a shield case (also called a metal frame) made of a metal plate, WD is a display window, INS1
3 to 3 are insulating sheets, PCBs 1 to 3 are circuit boards constituting driving means (PCB 1 is a drain side circuit board: a circuit board for driving a video signal line, PCB 2 is a gate side circuit board, PCB
3 is an interface circuit board), JN1 to 3 are joiners for electrically connecting the circuit boards PCB1 to PCB3, TC
P1 and TCP2 are tape carrier packages, PNL is a liquid crystal panel, GC is a rubber cushion, ILS is a light shielding spacer, PRS is a prism sheet, SPS is a diffusion sheet,
GLB is a light guide plate, RFS is a reflection sheet, MCA is a lower case (mold frame) formed by integral molding, MO is an MCA opening, LP is a fluorescent tube, LPC is a lamp cable, and GB supports a fluorescent tube LP. A rubber bush, BAT denotes a double-sided adhesive tape, BL denotes a backlight made of a fluorescent tube, a light guide plate, and the like, and a liquid crystal display module MDL is assembled by stacking diffusion plate members in the arrangement shown in the figure.

The liquid crystal display module MDL has two kinds of storage / holding members of a lower case MCA and a shield case SHD, and includes insulating sheets INS1 to INS3 and circuit boards PCB1 to PCB1.
3. A metal shield case SHD in which a liquid crystal panel PNL is stored and fixed, and a lower case MCA in which a backlight BL including a fluorescent tube LP, a light guide plate GLB, a prism sheet PRS, and the like are stored are combined.

An integrated circuit chip for driving each pixel of the liquid crystal panel PNL is mounted on the video signal line driving circuit board PCB1, and an interface circuit board PCB3
Is mounted with an integrated circuit chip that receives a video signal from an external host, receives a control signal such as a timing signal, and a timing converter TCON that processes timing to generate a clock signal.

The clock signal generated by the timing converter is integrated on the video signal line driving circuit board PCB1 via the clock signal line CLL laid on the interface circuit board PCB3 and the video signal line driving circuit board PCB1. Supplied to the circuit chip.

The interface circuit board PCB3 and the video signal line driving circuit board PCB1 are multilayer wiring boards, and the clock signal line CLL is connected to the interface circuit board PCB3 and the video signal line driving circuit board PC
It is formed as an inner wiring of B1.

The liquid crystal panel PNL has a drain-side circuit board PCB1, a gate-side circuit board PCB2, and an interface circuit board PCB3 for driving TFTs.
Are connected by tape carrier packages TCP1 and TCP2, and the circuit boards are connected by joiners JN1, JN2, JN3.

The liquid crystal panel PNL is an in-plane switching mode active matrix type liquid crystal display device according to the present invention, and includes the columnar spacer described in the above embodiment in order to maintain the distance between the two substrates at a predetermined value. ing.

FIG. 7 is a perspective view of a notebook computer as an example of an electronic apparatus on which the liquid crystal display device according to the present invention is mounted.

This notebook computer (portable personal computer) comprises a keyboard section (main body section) and a display section connected to the keyboard section by a hinge. Keyboard and host (host computer), CP
U and other signal generation functions, and the display unit has a liquid crystal panel P
NL, and drive circuit boards PCB1 and PCB
2, PCB3 with control chip TCON,
In addition, an inverter power supply board serving as a backlight power supply is mounted.

The liquid crystal display module described with reference to FIG. 11 in which the liquid crystal display panel PNL, the various circuit boards PCB1, PCB2, PCB3, the inverter power supply board, and the backlight are integrated is mounted.

[0068]

As described above, according to the present invention,
By making the front side and the rear side of the columnar spacer with respect to the rubbing direction acute, the resistance given to the rubbing cloth in the rubbing process is reduced, and the bristle of the rubbing cloth at the rear glass side of the columnar spacer has the shape of the columnar spacer. It is easy to restore to the original state along. Therefore, damage to the hairs of the rubbing cloth on the rear side of the columnar spacer is small, and rubbing failure on the rear side is also reduced.

Further, since the bottom and top areas of the columnar spacer are formed to have substantially the same area, the pressure exerted on the opposing substrate by the top of the columnar spacer can be reduced.
Damage to the insulating film and the protective film of the counter substrate can be prevented, and contamination of the liquid crystal can be avoided.

Further, since there is no transparent electrode such as ITO in the upper layer of the columnar spacer, only the columnar spacer, which is an insulator, comes into contact with the opposing substrate, and an electrical short circuit between the substrates does not occur.

As described above, according to the present invention, a liquid crystal display device for displaying images with high reliability and high quality can be obtained.

[Brief description of the drawings]

FIG. 1 is a plan view of a principal part for explaining a configuration near one pixel of a liquid crystal panel constituting a lateral electric field type active matrix type liquid crystal display device which is a first embodiment of a liquid crystal display device according to the present invention.

FIG. 2 is a cross-sectional view taken along line 1-1 'of FIG.

FIG. 3 is a schematic perspective view illustrating an example of the shape of a columnar spacer in the present embodiment.

FIG. 4 is a schematic explanatory view of a driving unit of a liquid crystal display device to which the present invention is applied.

FIG. 5 is an explanatory diagram of an example of a driving waveform of a liquid crystal display device to which the present invention is applied.

FIG. 6 is an exploded perspective view illustrating the overall configuration of the liquid crystal display device according to the present invention.

FIG. 7 is a perspective view of a notebook computer as an example of an electronic apparatus on which the liquid crystal display device according to the present invention is mounted.

FIG. 8 is a cross-sectional view of a main part illustrating a configuration of a conventional in-plane switching mode liquid crystal display device in which a spacer is formed by overlapping colored layers.

[Explanation of symbols]

DL Video signal line SD2 Drain electrode extending from video signal line CL Counter voltage signal line CT Counter electrode same as counter voltage signal line PX Pixel electrode SD1 Source electrode same as pixel electrode Cstg Storage capacitance GL Scan signal line GT Same as scan electrode Gate electrode BM Black matrix (indicated by the boundary of the opening of the pixel portion) TFT Thin film transistor SP Columnar spacer.

Continued on the front page (72) Inventor Shigeru Matsuyama 3300 Hayano Mobara-shi, Chiba Pref.Electronic Device Division, Hitachi, Ltd. (Reference) 2H089 HA29 LA09 LA10 LA16 LA19 LA20 MA04X NA13 PA06 PA08 QA14 QA15 TA04 2H090 HD14 LA02 2H092 NA04 PA03 5C094 AA03 AA06 AA07 BA03 BA43 CA24 DA13 EC03 HA08

Claims (3)

[Claims] 1. A pair of substrates, at least one of which is transparent, at least two or more types of color filters having different colors for color display formed on one of the pair of substrates, and black interposed between the color filters. A matrix, an electrode group formed over the other of the pair of substrates, a layer of a liquid crystal composition having dielectric anisotropy between the pair of substrates, and molecules of the layer of the liquid crystal composition. A liquid crystal panel having an alignment control layer for arranging the array in a predetermined direction, a polarizing plate laminated on each of the pair of substrates with the polarization axes orthogonal to each other, and applying a driving voltage to the electrode group. Wherein the electrode group is arranged such that a voltage mainly parallel to an interface between the alignment control layer and the liquid crystal composition layer is applied. An electrode array structure, at least one of the pair of substrates has a columnar spacer on an upper layer of the black matrix and the color filter, and the columnar spacer has substantially the same area at the bottom side and the top and at the substrate surface The cross section in the direction parallel to the rubbing direction has a shape having an acute angle with respect to the rubbing direction, and the top of the alignment control layer formed on the columnar spacer is in contact with the alignment control layer formed on the other substrate. A liquid crystal display device comprising: 2. The method according to claim 1, wherein the columnar spacer is formed by patterning an organic film formed above the black matrix and the color filter and below the orientation control layer. Liquid crystal display. 3. The liquid crystal display device according to claim 1, wherein the columnar spacer has a higher dielectric constant or higher conductivity than that of the liquid crystal composition.