JPH11202787A - Liquid crystal display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make a liquid crystal display module fixable to the case of a display part without using a screw. SOLUTION: For this liquid crystal display device, the liquid crystal display module MDL composed by fixing a liquid crystal panel PNL composed by holding a liquid crystal layer interposing between a pair of oppositely arranged transparent substrates SUB1 and SUB2 provided with an electrode for picture element selection on at least one of them, a driving circuit means for applying a voltage corresponding to display signals to the liquid crystal panel PNL and a back light BL installed on the back surface of the liquid crystal panel PNL by an upper frame SHD1 and a lower frame SHD 2 connected to the upper frame SHD1 is mounted to the case CASE for constituting the display part. The liquid crystal display module MDL is provided with at least one each of tabs TAB1-TAB4 provided projectingly outwards on the parallel two sides of one or both of the upper frame SHD1 and the lower frame SHD2 and the case CASE is provided with a bottom surface and at least a pair of opposing side walls where tab receiving holes facing the bottom surface are formed. By engaging the tabs TAB1-TAB4 with the tab receiving holes, the liquid crystal display module MDL is fixed to the case CASE.

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 liquid crystal display device having a reduced external dimension by attaching a liquid crystal display module without using a screw in a case of a display unit.

[0002]

2. Description of the Related Art In a liquid crystal display device capable of high-definition display for a notebook computer or a computer monitor, a liquid crystal panel, a driving circuit board for driving the liquid crystal panel, and a light source for illuminating the liquid crystal panel from behind (a so-called back light). (Lights) are laminated, sandwiched and fixed between an upper frame and a lower frame to form a liquid crystal display module, which is fixed to the display case of the notebook computer or the computer monitor.

[0003] To fix the liquid crystal display module to the case of the display section, a screw hole is formed in a tab protruding from two parallel sides of the liquid crystal display module, and a screw is formed between the screw hole and a boss formed in the case. It is common to fix via

FIG. 22 is a plan view of a display section for explaining a fixing structure of a liquid crystal display module in a conventional liquid crystal display device.
FIG. 23 is a partial cross-sectional view taken along the line AA of FIG. 22 and illustrates a display unit of a notebook computer as an example.

In FIGS. 22 and 23, the display unit has a case CASE having a side wall surrounding a bottom surface, and the case CASE.
And a liquid crystal display module MDL mounted therein. The liquid crystal display module MDL includes a first substrate SUB1
A liquid crystal panel PNL composed of polarizing plates POL1 and POL2 with a liquid crystal layer sandwiched between the first substrate and the second substrate SUB2 and adhered to the front and rear surfaces, respectively, and a backlight BL installed on the rear surface of the liquid crystal panel PNL as an upper frame. The SHD1 and the lower frame SHD2 are fixed via a spacer such as a rubber cushion GC. A drive circuit board and the like on which a circuit for driving the liquid crystal panel is mounted are not shown.

The liquid crystal display module MDL is provided with four tabs TAB1, TAB2, TAB3, and TAB4 having screw holes protruding from the upper frame SHD1 and the lower frame SHD on each of two opposing parallel sides thereof. Boss B with four tabs formed on the bottom of case CASE
Align the screw receiving holes formed in the OS with the screws SCR1,
Fixed at SCR2, SCR3, SCR4.

HNG1 and HNG2 are hinges for rotatably mounting the main body of the notebook computer.

A backlight is a backlighting device for visualizing an image generated on a liquid crystal. In a notebook computer which is required to be thin, a so-called backlight in which a linear light source is arranged on a side edge of a light guide plate is used. A side edge type is employed, and a side edge type is also used in a liquid crystal display device for a monitor in order to reduce the depth.

However, large-sized liquid crystal display devices such as a computer monitor often employ a direct-type backlight to obtain higher-luminance illumination light.

[0010] Each type of backlight is modularized together with a liquid crystal panel, and is housed and fixed in a case of a display unit.

As described above, this type of liquid crystal display device basically constitutes a so-called liquid crystal panel in which a liquid crystal layer is sandwiched between two substrates at least one of which is made of transparent glass or the like. Image display is performed by applying a required voltage or the like to various electrodes for pixel formation formed on one or both of the two substrates constituting the liquid crystal panel from a driving circuit incorporated in the periphery of the panel.

This image formation is performed by selectively applying a voltage to various electrodes for pixel formation formed on the substrate of the liquid crystal panel to turn on and off a predetermined pixel. By forming an element and selecting this active element, the method is classified into a type of turning on and off a predetermined pixel.

The latter type of liquid crystal display device is called an active matrix type, and is the mainstream of the liquid crystal display device because of its contrast performance, high-speed display performance and the like. A conventional active matrix type liquid crystal display device employs a so-called vertical electric field method in which an electric field for changing the orientation direction of a liquid crystal layer is applied between an electrode formed on one substrate and an electrode formed on the other substrate. I was

In recent years, the direction of an electric field applied to a liquid crystal layer is set to a direction substantially parallel to the substrate surface.
A liquid crystal display device of the PS type is also realized. As this in-plane switching mode liquid crystal display device, a device in which a very wide viewing angle is obtained by using a comb electrode on one of two substrates is known (Japanese Patent Publication No. 63-21907,
U.S. Pat. No. 4,345,249).

[0015]

The screen size of such a liquid crystal panel has been increasing year by year, and a so-called narrow frame has been demanded in order to accommodate the liquid crystal panel in a limited display case. .

In the conventional fixing structure shown in FIGS. 20 and 21, from the viewpoint of mounting strength, M3.0 or M3.0 is generally used.
3.5 screws are used. For this reason, there is a limitation in reducing the size of the tab for attaching the liquid crystal display module to the display unit of a limited size, and as a result, there has been a problem that the width of the picture frame cannot be reduced to some extent. .

In the case of using a conventional screw, it is necessary to ensure the strength of the boss receiving the screw.
There is also a problem that it is difficult to reduce the thickness.

An object of the present invention is to solve the above-mentioned problems of the prior art, and to fix the liquid crystal display module to the case of the display unit without using screws, so that even if the liquid crystal panel becomes large in size, the frame can be formed. It is an object of the present invention to provide a liquid crystal display device that can respond to the narrowing.

[0019]

In order to achieve the above object, according to the present invention, a tab having no screw holes is provided on two parallel sides of a liquid crystal display module, and a case of a display unit, Alternatively, a tab receiving hole is formed at a position corresponding to the tab of the reinforcing member installed in the case, and the tab is engaged with the tab receiving hole, thereby fixing the liquid crystal display module without screws.

That is, the present invention provides the following (1) to (3)
It is characterized by having the configuration of (1) A liquid crystal panel having a liquid crystal layer sandwiched between a pair of transparent substrates having a pixel selection electrode on at least one of them opposed to each other, and a drive for applying a voltage according to a display signal to the panel. A liquid crystal display device in which a liquid crystal display module in which a circuit means and a backlight installed on the back of the liquid crystal panel are fixed by an upper frame and a lower frame connected to the upper frame is mounted on a case forming a display unit. The liquid crystal display module includes at least one tab protruding outward on two parallel sides of one or both of the upper frame and the lower frame, and the case faces the bottom surface and the bottom surface. The liquid crystal display module has at least a pair of opposing side walls formed with tab receiving holes. Characterized by being fixed to the case.

The number of the tabs may be one per each side, but by forming two tabs, reliable fixing can be achieved. Further, the number of the tabs may be three on each side, or the number of tabs may be different between one side and the other side.

In this configuration, the tab of the liquid crystal display module may be engaged with the tab receiving hole formed in the case by a response curved outward using the elasticity of the case.

Accordingly, even when the screen size of the liquid crystal panel becomes large, it is possible to cope with the narrow frame, and it is possible to provide a liquid crystal display device in which the number of parts is reduced and the assembling process is simplified.

(2) A liquid crystal panel having a liquid crystal layer sandwiched between a pair of transparent substrates having a pixel selection electrode on at least one of them facing each other, and applying a voltage corresponding to a display signal to the panel. Liquid crystal display module comprising a liquid crystal display module in which a driving circuit means for fixing a liquid crystal display module and a backlight installed on the back of the liquid crystal panel are fixed by an upper frame and a lower frame connected to the upper frame. In the display device, the liquid crystal display module includes at least one tab projecting outward on two sides parallel to one or both of the upper frame and the lower frame, and the case has a bottom surface and a bottom surface. A side wall provided with a tab receiving hole on one side wall, and a side wall provided with the tab receiving hole and an inner side wall opposed to each other across the bottom surface. The liquid crystal display module has a reinforcing member fixed to the case with a tab receiving hole, and the tab of the liquid crystal display module is engaged with the tab receiving hole of the side wall and the tab receiving hole of the reinforcing member. It is characterized by being fixed to the case.

The number of the tabs may be one for each side as in the case of (1), but by forming two tabs, the tab can be securely fixed. Further, the number of the tabs may be three on each side, or the number of tabs may be different between one side and the other side.

In this configuration, the tab on one side of the liquid crystal display module is engaged with the tab receiving hole of the reinforcing member before being incorporated in the case first, and then the other side is inserted into the tab receiving hole formed in the case. And the reinforcing member is fixed.

This makes it possible to provide a liquid crystal display device which can cope with an increase in the size of the screen of the liquid crystal panel by reducing the frame width, simplifying the assembling process by reducing the number of parts.

(3) A liquid crystal panel having a liquid crystal layer sandwiched between a pair of transparent substrates having a pixel selection electrode on at least one of them facing each other, and applying a voltage corresponding to a display signal to the panel. Liquid crystal display module comprising a liquid crystal display module in which a driving circuit means for fixing a liquid crystal display module and a backlight installed on the back of the liquid crystal panel are fixed by an upper frame and a lower frame connected to the upper frame. In the display device, the liquid crystal display module includes at least one tab protruding from each of parallel side surfaces of one or both of the upper frame and the lower frame, and has parallel side walls facing each other with the bottom surface interposed therebetween. A pair of reinforcing members fixed to the case with tab receiving holes provided inside the case, and the liquid crystal display module is provided in the tab receiving holes of the pair of reinforcing members. By engaging the tab of Yuru, characterized in that fixing the liquid crystal display module to said casing.

The tabs are similar to the tabs (1) and (2).
One piece may be provided for each side, but two pieces can be securely fixed. Further, the number of the tabs may be three on each side, or the number of tabs may be different between one side and the other side.

In this configuration, the tabs on each side of the liquid crystal display module are engaged with the tab receiving holes of the reinforcing member before being incorporated into the case, and then the reinforcing member is fixed to the case.

This makes it possible to provide a liquid crystal display device which can cope with the case where the screen of the liquid crystal panel has a large screen by reducing the width of the frame, reduce the number of parts, and simplify the assembling process.

[0032]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below in detail with reference to examples.

FIG. 1 is a plan view of a display unit for explaining a fixing structure of a liquid crystal display module in a liquid crystal display device according to a first embodiment of the present invention, and FIG. 2 is a partial cross-sectional view taken along line AA of FIG. The present invention is applied to a display portion of a notebook computer.

In FIGS. 1 and 2, the display unit has a case CASE having a side wall surrounding the bottom surface as in the conventional example, and a liquid crystal display module MDL mounted in the case CASE.
It is composed of The liquid crystal display module MDL has the first
Polarizer POL having a liquid crystal layer sandwiched between the substrate SUB1 and the second substrate SUB2, and attached to the front and back surfaces, respectively.
A liquid crystal panel PNL comprising POL1 and POL2 and a backlight BL installed on the back of the liquid crystal panel PNL are fixed to the upper frame SHD1 and the lower frame SHD2 via a spacer such as a rubber cushion GC. A drive circuit board and the like on which a circuit for driving the liquid crystal panel is mounted are not shown.

Then, four tabs TAB1 and TAB1 protruding from the upper frame SHD1 and the lower frame SHD on each of two opposite parallel sides of the liquid crystal display module MDL.
AB2, TAB3, and TAB4 are provided. Case C in which these four tabs are made of a material having some flexibility
The ASE is engaged with and fixed to the tab receiving hole ALC formed in the inner wall of the ASE.

The tabs TAB1, TAB2 and TA of this embodiment
Since B3 and TAB4 do not require a conventional screw hole, their protruding length can be made shorter than before. For example, the conventional tab has a diameter of about 7 mm, which is about 3 mm.
Degree.

HNG1 and HNG2 are hinges for rotatably mounting the main body of the notebook computer.

In this embodiment, the tab receiving hole ALC formed in the inner wall of the case CASE and the liquid crystal display module MDL
The tab TAB of the liquid crystal display module MDL is engaged with one of the tab receiving holes ALC of the case CASE, and then the case CASE is bent to the rear side, and the flexibility of the case CASE is adjusted. The tab TAB on the remaining side of the liquid crystal display module MDL is engaged with the other side of the liquid crystal display module MDL using the above.

This makes it possible to provide a liquid crystal display device in which the frame width can be reduced even when the size of the screen of the liquid crystal panel is increased, and the number of components is reduced and the assembly process is simplified.

FIG. 3 is a plan view of a display unit for explaining a fixing structure of a liquid crystal display module in a liquid crystal display device according to a second embodiment of the present invention, and FIG. 4 is a partial cross-sectional view taken along line BB of FIG. As in the first embodiment, the present invention is applied to a display unit of a notebook computer. Note that FIG.
2 is the same as FIG.

In FIGS. 3 and 4, the basic configuration of the liquid crystal display module MDL is the same as that of the first embodiment, and a description thereof will be omitted. In this embodiment, a tab receiving hole similar to that of FIG. 2 is formed inside one side wall (right side in the figure) of the case CASE, and a reinforcing member ST2 is provided in the other side wall (left side in the figure). A tab receiving hole ALC is formed in the reinforcing member ST2. Although the tab receiving holes ALC formed in the reinforcing member ST2 are shown as through holes, they may be holes that do not penetrate.

Also, four tabs TAB1, TAB2 and TAB3, TAB protruding from the upper frame SHD1 on two opposite parallel sides of the liquid crystal display module MDL.
4 is provided. Tab TAB on one side of these four tabs
1, TAB2 is engaged with a tab receiving hole formed on one side wall of the case CASE, and the other tabs TAB3, TAB4
Is engaged with the tab receiving hole ALC formed in the reinforcing member ST2.

In this embodiment, first, the tab T of the liquid crystal display module MDL is inserted into the tab receiving hole ALC of the reinforcing member ST2.
After engaging AB3 and TAB4, tabs TAB1 and TAB
2 is engaged with the tab receiving hole formed in the case CASE,
The reinforcing member ST2 is fixed to the case CASE.

According to this embodiment, even when the size of the screen of the liquid crystal panel is increased, the frame width can be reduced, and the number of components can be reduced and the assembly process can be simplified to provide a liquid crystal display device.

FIG. 5 is a plan view of a display portion for explaining a fixing structure of a liquid crystal display module in a liquid crystal display device according to a third embodiment of the present invention, and FIG. 6 is a partial cross-sectional view taken along line AA of FIG. As in the first and second embodiments, the present invention is applied to the display unit of a notebook computer.

In FIGS. 5 and 6, the basic structure of the liquid crystal display module MDL is the same as that of the first embodiment, and the description is omitted. In this embodiment, reinforcing members ST1 and ST2 are provided inside one side wall (right side in the figure) and inside the other side wall (left side in the figure) of the case CASE.
1 and SY2 are formed with tab receiving holes ALC. In addition,
Although the tab receiving holes ALC formed in the reinforcing members ST1 and ST2 are shown as through holes, they may be holes that do not penetrate.

Also, four tabs TAB1, TAB2 and TAB3, TAB protruding from the upper frame SHD1 on each of two opposing parallel sides of the liquid crystal display module MDL.
4 is provided. After the four tabs TAB1, TAB2 and the tabs TAB3, TAB4 are respectively engaged with the tab receiving holes ALC formed in the reinforcing members ST1, ST2, the two reinforcing members ST1, ST2 are fixed to the case CASE.

According to this embodiment, even when the size of the screen of the liquid crystal panel is increased, the width of the frame can be reduced, and the number of components can be reduced and the assembly process can be simplified to provide a liquid crystal display device.

The shape of the tab in each of the above embodiments is arbitrary, and it can be formed on either the upper frame, the lower frame, or the upper and lower frames, and the embodiments can be combined and applied.

As described above, according to each embodiment of the present invention,
Since no screws are used when fixing the liquid crystal display module to the display case, the space required for forming screws and screw holes is not required, making it easier to reduce the width of the frame or reduce the size of the same screen size. At the same time, the display portion can be made thinner.

FIG. 7 is a perspective view of a notebook computer for explaining an overall example of a liquid crystal display device according to the present invention.

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.

Then, the liquid crystal display panel PNL, the various circuit boards PCB1, PCB2, PCB3, the inverter power supply board, and the liquid crystal display module integrated with the backlight are fixed by any one of the structures of the above embodiments. . Thus, a notebook computer with a narrower frame can be obtained.

Next, the details of the liquid crystal display device of the present invention are shown in FIG.
This will be described with reference to FIG.

FIG. 8 is a plan view showing one pixel of an active matrix type color liquid crystal display device which is an example of the liquid crystal display device of the present invention, a light shielding region of the black matrix BM, and its periphery.

As shown in FIG. 8, each pixel has a scanning signal line (gate signal line or horizontal signal line) GL, a counter voltage signal line (counter electrode line) CL, and two adjacent video signal lines (drain). The signal line or the vertical signal line) is arranged in an intersecting region with the DL (in a region surrounded by four signal lines).

Each pixel includes a thin film transistor TFT, a storage capacitor Cstg, a pixel electrode PX, and a counter electrode CT. The scanning signal lines GL and the counter voltage signal lines CL extend in the left-right direction in FIG. The video signal lines DL extend in the up-down direction, and a plurality of video signal lines DL are arranged in the left-right direction. The pixel electrode PX is connected to the thin film transistor TFT, and the counter electrode CT is integrated with the counter voltage signal line CL.

The pixel electrode PX and the counter electrode CT are opposed to each other, and the alignment state of the liquid crystal LC is controlled by the electric field between each pixel electrode PX and the counter electrode CT, and the transmitted light is modulated to control the display. The pixel electrode PX and the counter electrode CT are formed in a comb-like shape, and each is an electrode that is elongated in the vertical direction in FIG.

The number O (the number of comb teeth) of the counter electrode CT in one pixel is equal to the number P (the number of comb teeth) of the pixel electrode PX and O =
It is configured to always have the relationship of P + 1 (O = 2, P = 1 in this embodiment). This is because the counter electrode CT and the pixel electrode PX are alternately arranged, and the counter electrode CT is always adjacent to the video signal line DL.

Thus, the counter electrode CT and the pixel electrode PX are
The electric field lines from the video signal line DL can be shielded by the counter electrode CT so that the electric field between them is not affected by the electric field generated from the video signal line DL.

Since the potential of the counter electrode CT is always supplied from the outside by the counter voltage signal line CL, the potential is stable. Therefore, there is almost no change in potential even adjacent to the video signal line DL. In addition, since the geometric position of the pixel electrode PX from the video signal line DL becomes farther,
The parasitic capacitance between the pixel electrode PX and the video signal line DL is greatly reduced, and the fluctuation of the pixel electrode potential Vs due to the video signal voltage can be controlled.

Thus, it is possible to suppress crosstalk (defective image quality called vertical smear) occurring in the vertical direction.

The electrode width W between the pixel electrode PX and the counter electrode CT
Each of p and Wc is set to 6 μm, which is set sufficiently larger than 4.5 μm which exceeds the maximum set thickness of the liquid crystal layer described later.
It is preferable to have a margin of 20% or more in consideration of processing variations in manufacturing. Therefore, it is preferable that the margin be sufficiently larger than 5.4 μm.

Thus, the electric field component applied to the liquid crystal layer parallel to the substrate surface becomes larger than the electric field component in the direction perpendicular to the substrate surface, and it is possible to suppress an increase in the voltage for driving the liquid crystal. The maximum value of the electrode width Wp, Wc of each electrode is
It is preferable that the distance be smaller than the distance L between the pixel electrode PX and the counter electrode CT.

This is because, if the distance between the electrodes is too small, the curvature of the lines of electric force becomes severe, and the area where the electric field component perpendicular to the substrate surface is larger than the electric field component parallel to the substrate surface increases. This is because an electric field component parallel to the above cannot be efficiently applied to the liquid crystal layer. Therefore, the pixel electrode PX and the counter electrode C
The interval L between T needs to be larger than 7.2 μm if the margin is 20%. In this embodiment, the diagonal is about 1
Since the pixel pitch is about 60 μm because the resolution is 4.5 cm (5.7 inches) and the resolution is 640 × 480 dots, the distance L> 7.2 μm by dividing the pixel into two.
Was realized.

The electrode width of the video signal line DL is set to 8 μm, which is slightly wider than the pixel electrode PX and the counter electrode CT in order to prevent disconnection, and the interval between the video signal line DL and the counter electrode CT is short-circuited. In order to prevent this, an interval of about 1 μm is provided, a video signal line DL is formed on the upper side of the gate insulating film, and a counter electrode CT is formed on the lower side.

On the other hand, the electrode interval between the pixel electrode PX and the counter electrode CT changes depending on the liquid crystal material used. this is,
Since the electric field strength that achieves the maximum transmittance varies depending on the liquid crystal material, the electrode spacing is set according to the liquid crystal material, and within the range of the maximum amplitude of the signal voltage set by the withstand voltage of the video signal driving circuit (signal side driver) used. , So that the maximum transmittance can be obtained. When a liquid crystal material described later is used, the electrode interval is about 15 μm.

In this configuration example, the black matrix BM is formed on the gate line GL, the counter voltage signal line CL, the thin film transistor TFT, the drain line DL, and between the drain line DL and the counter electrode CT in plan view.

<< Cross-Sectional Structure of Matrix (Pixel) >> FIG. 9 shows a thin film transistor TF taken along the line FF in FIG.
FIG. 10 is a cross-sectional view of the storage capacitor Cstg taken along the line GG in FIG. 8, and FIG. 11 is a cross-sectional view of the vicinity of an electrode of one pixel in an image display area of a horizontal electric field type liquid crystal display substrate and the periphery of the substrate It is sectional drawing of a part.

As shown in FIG. 11, a thin film transistor TFT, a storage capacitor Cstg (not shown) and an electrode group C are provided on the lower transparent glass substrate SUB1 side with respect to the liquid crystal layer LC.
T, PX are formed, and a color filter FIL and a black matrix B for shading are formed on the upper transparent glass substrate SUB2 side.
An M pattern is formed. Although not publicly known,
As proposed in Japanese Patent Application No. 7-198349 by the same applicant, it is also possible to form the pattern of the light-shielding black matrix BM on the lower transparent glass substrate SUB1 side.

On the inner surface (on the liquid crystal LC side) of each of the transparent glass substrates SUB1 and SUB2, there are provided alignment films ORI11 and ORI12 for controlling the initial alignment of the liquid crystal, and the transparent glass substrates SUB1 and SUB2 are provided with alignment films ORI11 and ORI12. Polarizing plates POL1 and POL2 whose polarization axes are orthogonally arranged (crossed Nicol arrangement) are provided on the outer surfaces of each.

Next, the lower transparent glass substrate SUB1 side (T
The configuration of the FT substrate will be described in detail.

TFT Substrate << Thin Film Transistor >> The thin film transistor TFT operates so that the channel resistance between the source and the drain decreases when a positive bias is applied to the gate electrode GT, and the channel resistance increases when the bias is set to zero.

As shown in FIG. 10, the thin-film transistor TFT has a gate electrode GT, a gate insulating film GI, and an i-type (intrinsic, not doped with a conductivity type determining impurity) amorphous silicon (Si) film. Type semiconductor layer AS, a pair of source electrode SD1, drain electrode SD
2

It should be understood that the source and the drain are originally determined by the bias polarity between them, and in the circuit of this liquid crystal display device, the polarity is inverted during the operation, so that the source and the drain are understood to be switched during the operation. However, in the following description, one is fixed and the other is fixed as a drain for convenience.

<< Gate Electrode GT >> The gate electrode GT is formed continuously with the scanning signal line GL, and a part of the scanning signal line GL is configured as the gate electrode GT. The gate electrode GT is a portion exceeding the active region of the thin film transistor TFT, and is formed larger than that so as to completely cover the i-type semiconductor layer AS (as viewed from below).

Thus, in addition to the role of the gate electrode GT itself, the gate electrode GT is designed so that external light and backlight do not hit the i-type semiconductor layer AS. In this example, the gate electrode GT is formed of a single-layer conductive film g1. As the conductive film g1, for example, an aluminum (Al) film formed by sputtering is used, and an anodic oxide film AOF of Al is provided thereon.

<< Scanning Signal Line GL >> The scanning signal line GL is formed of the conductive film g1. The conductive film g1 of the scanning signal line GL is formed in the same manufacturing process as the conductive film g1 of the gate electrode GT, and is integrally formed. Through this scanning signal line GL, a gate voltage Vg is supplied from an external circuit to the gate electrode GT.

An anodic oxide film AOF of Al is also provided on the scanning signal line GL. The portion that intersects with the video signal line DL is made thin to reduce the probability of short-circuit with the video signal line DL, and is made bifurcated so that even if it is short-circuited, it can be separated by laser trimming.

<< Counter Electrode CT >> The counter electrode CT is formed of the same conductive film g1 as the gate electrode GT and the scanning signal line GL. Also, an anodic oxide film A of Al is formed on the counter electrode CT.
An OF is provided. The counter electrode CT has an anodic oxide film A
Since they are completely covered with the OF, even if they are brought as close as possible to the video signal lines, they will not be short-circuited.

Further, they may be configured to cross each other. The counter electrode CT is configured to apply a counter voltage Vcom. In this embodiment, the counter voltage Vc
om is a potential lower than an intermediate DC potential between the minimum level drive voltage Vdmin and the maximum level drive voltage Vdmax applied to the video signal line DL by a feedthrough voltage ΔVs generated when the thin film transistor element TFT is turned off. However, if you want to reduce the power supply voltage of the integrated circuit used in the video signal drive circuit to about half,
An AC voltage may be applied.

<< Counter Voltage Signal Line CL >> Counter Voltage Signal Line C
L is composed of the conductive film g1. The conductive film g1 of the counter voltage signal line CL is formed in the same manufacturing process as the conductive film g1 of the gate electrode GT, the scanning signal line GL, and the counter electrode CT, and is formed integrally with the counter electrode CT.

The counter voltage Vcom is supplied from the external circuit to the counter electrode CT through the counter voltage signal line CL. or,
An anodic oxide film AOF of Al is also provided on the counter voltage signal line CL. Note that the portion that intersects with the video signal line DL is
Like the scanning signal line GL, it may be made thinner to reduce the probability of short-circuiting with the video signal line DL, or it may be split into two parts so that even if it is short-circuited, it can be separated by laser trimming.

<< Insulating Film GI >> The insulating film GI is used as a gate insulating film for applying an electric field to the semiconductor layer AS together with the gate electrode GT in the thin film transistor TFT. The insulating film GI is formed above the gate electrode GT and the scanning signal line GL.

As the insulating film GI, for example, plasma CVD
The silicon nitride film formed by
It is formed to a thickness of nm (240 nm in this embodiment).

The gate insulating film GI is formed in the matrix portion A
R is formed so as to surround the entirety of R, and the peripheral portion is removed so as to expose the external connection terminals DTM and GTM. Also,
The insulating film GI also contributes to electrical insulation between the scanning signal lines GL and the counter voltage signal lines CL and the video signal lines DL.

<< i-type semiconductor layer AS >> i-type semiconductor layer AS
Is amorphous silicon and is formed with a thickness of 20 to 220 nm (in this example, a thickness of about 200 nm). The layer d0 is made of N doped with phosphorus (P) for ohmic contact.
This is a (+) type amorphous silicon semiconductor layer, which is left only where the i-type semiconductor layer AS exists below and the conductive film d1 (d2) exists above.

The i-type semiconductor layer AS is also provided between the scanning signal line GL and the intersection of the opposite signal line CL and the video signal line DL. The i-type semiconductor layer AS at the intersection reduces a short circuit between the scanning signal line GL and the opposing signal line CL and the video signal line DL at the intersection.

<< Source electrode SDI, drain electrode SD
2 >> Each of the source electrode SDI and the drain electrode SD2 is composed of a conductive film d1 in contact with the N (+) type semiconductor layer d0 and a conductive film d2 formed thereon.

The conductive film d1 is formed with a thickness of 50 to 100 nm (about 60 nm in this embodiment) using a chromium (Cr) film formed by sputtering. Since the stress increases when the Cr film is formed to have a large thickness, the Cr film has a thickness of 200 nm.
It is formed in a range that does not exceed a certain thickness. Cr film is N
To improve the adhesion to the (+) type semiconductor layer d0,
2 is used for the purpose of a so-called barrier layer that prevents Al from diffusing into the N (+) type semiconductor layer d0.

As the conductive film d1, a refractory metal (Mo, Ti, Ta, W) film or a refractory metal silicide (MoSi ₂ , TiSi ₂ , TaSi ₂ , WSi ₂ ) film may be used in addition to the Cr film. .

The conductive film d2 has a thickness of 30
It is formed to a thickness of about 0 to 500 nm (about 400 nm). The Al film has a smaller stress than the Cr film and can be formed to have a large thickness, and can reduce the resistance values of the source electrode SD1, the drain electrode SD2 and the video signal line DL, and can reduce the gate electrode GT and the i-type semiconductor. There is a function of ensuring the overcoming of the step caused by the layer AS (improving the step coverage).

After patterning the conductive films d1 and d2 with the same mask pattern, the N (+) type semiconductor layer d0 is removed using the same mask or using the conductive films d1 and d2 as a mask. That is, the i-type semiconductor layer AS
The remaining N (+) type semiconductor layer d0 is a conductive film d1,
Portions other than the conductive film d2 are removed by self-alignment.
At this time, since the N (+)-type semiconductor layer d0 is etched so as to completely remove its thickness, the i-type semiconductor layer A is removed.
Although the surface portion of S is also slightly etched, its degree may be controlled by the etching time.

<< Video Signal Line DL >> The video signal line DL is composed of the second conductive film d2 and the third conductive film d3 in the same layer as the source electrode SD1 and the drain electrode SD2. The video signal line DL is formed integrally with the drain electrode SD2.

<< Pixel Electrode PX >> The pixel electrode PX is a second conductive film d of the same layer as the source electrode SD1 and the drain electrode SD2.
2, the third conductive film d3. Also, the pixel electrode P
X is formed integrally with the source electrode SD1.

<< Storage Capacitor Cstg >> The pixel electrode PX is formed so as to overlap the counter voltage signal line CL at the end opposite to the end connected to the thin film transistor TFT. This superposition constitutes a storage capacitor (capacitance element) Cstg having the pixel electrode PX as one electrode PL2 and the counter voltage signal line CL as the other electrode PL1, as is apparent from FIG. The dielectric film of the storage capacitor Cstg includes an insulating film GI used as a gate insulating film of the thin film transistor TFT and an anodic oxide film AOF.

As shown in FIG. 8, the storage capacitor Cstg is formed in the conductive film g1 of the counter voltage signal line CL in plan view.

In this case, the storage capacitor Cstg is made of Al because the material of the electrode positioned below the insulating film GI is made of Al and the surface is anodized. It is possible to obtain a storage capacitor which is less likely to cause adverse effects due to a point defect (short-circuit with an electrode positioned on the upper side) caused by a so-called hillock or the like.

<< Protective Film PSV1 >> Thin Film Transistor TF
On T, a protective film PSV1 is provided. Protective film PS
V1 is formed mainly to protect the thin film transistor TFT from moisture and the like, and uses a material having high transparency and good moisture resistance. The protective film PSV1 is formed of, for example, a silicon oxide film or a silicon nitride film formed by a plasma CVD apparatus, and has a thickness of about 500 nm.

The protective film PSV1 is formed so as to surround the entire matrix part AR, and the peripheral part is connected to the external connection terminal DT.
M and GTM have been removed to expose. Regarding the thickness relationship between the protective film PSV1 and the gate insulating film GI, the former is made thicker in consideration of the protective effect, and the latter is made thinner in consideration of the transconductance gm of the transistor.

[0102] The color filter substrate Next, FIG. 11, the upper transparent glass substrate SUB by 14
The configuration of the two sides (color filter substrate) will be described in detail.

<< Light shielding film BM >> Upper transparent glass substrate SUB
On the second side, an unnecessary gap (pixel electrode PX and counter electrode CT)
Transmitted light from the gap other than the gap between
A light-shielding film BM (a so-called black matrix) is formed so as not to lower the contrast ratio and the like. Light shielding film BM
Also serves to prevent external light or backlight light from entering the i-type semiconductor layer AS. That is, the i-type semiconductor layer AS of the thin film transistor TFT is sandwiched between the upper and lower light-shielding films BM and the large gate electrode GT, so that external natural light or backlight does not shine.

The closed rectangular outline of the light shielding film BM shown in FIG. 8 indicates an opening on the inside of which the light shielding film BM is not formed. This contour pattern is an example.

In a horizontal electric field type liquid crystal display device, a black matrix having the highest possible resistance is suitable.
Generally, a resin composition is used. For this resistance standard,
Although it is not publicly known, Japanese Patent Application No. 7-1919 filed by the same applicant
No. 94. That is, if the specific resistance of the liquid crystal composition LC is described as 10 ^N as 10 ^N , then the specific resistance of the black matrix BM is 10 ^N Ω · cm or more, and the specific resistance of the black matrix BM is 10 M
When written as 10 ^M and 10 ^M Ω · cm or more and, N ≧
9, a relationship that satisfies M ≧ 6. Alternatively, N ≧ 13,
It is desirable that the relationship satisfy M ≧ 7.

Further, from the viewpoint of reducing the surface reflection of the liquid crystal display device, it is desirable to use a resin composition as a material for forming the black matrix.

Further, as compared with the case where a metal film such as Cr is used for the black matrix, the step of etching the metal film is unnecessary, so that the manufacturing process of the color filter substrate can be simplified. When a metal film is used, the manufacturing steps are: 1) metal film formation, 2) resist coating, 3) exposure, 4) development, 5)
Metal film etching, 6) resist stripping.

On the other hand, when a resin is used, the manufacturing process is as follows.
1) resin application, 2) exposure, and 3) development, and the process can be significantly shortened.

However, the resin composition has a lower light-shielding property than the metal film. Increasing the thickness of the resin improves the light-shielding properties, but increases the variation in the thickness of the black matrix. This means that, for example, when there is a thickness variation of ± 10%, when the thickness of the black matrix is 1.0 μm, ± 0.1 μm,
This is because when it is 2 μm, it becomes ± 0.2 μm.

When the thickness of the black matrix is increased, the variation in the thickness of the color filter substrate increases, and it becomes difficult to improve the gap accuracy of the liquid crystal display substrate.
For the above reasons, it is desirable that the thickness of the resin is 2 μm or less.

In order to increase the OD value to about 4.0 or more at a film thickness of 1 μm, for example, when blackening is performed by increasing the carbon content, the specific resistance value of the black matrix BM is about 10 ⁶
Ω · cm or less and cannot be used at present. OD
The value can be defined as the value obtained by multiplying the extinction coefficient by the film thickness.

For this reason, in this embodiment, the light shielding film BM
Is formed of a resin composition obtained by mixing a black inorganic pigment into a resist material, and is formed to a thickness of about 1.3 ± 0.1 μm. Examples of the inorganic pigment include palladium and electroless plated Ni. Further, the specific resistance of the black matrix BM was set to about 10 ⁹ Ω · cm, and the OD value was set to about 2.0.

The calculation result of the light transmission amount when this resin composition black matrix BM is used is shown below.

OD value = log (100 / Y) Y = ∫A (λ) · B (λ) · C (λ) dλ / ∫A (λ)
C (λ) dλ Here, A is the visibility, B is the transmittance, C is the light source spectrum, and λ is the wavelength of the incident light.

When light is shielded by a film having an OD value of 2.0, Y = 1% is obtained from the above equation (1), and the incident light intensity is 4000 cd /
Assuming m ² , about 40 cd / m ² of light will be transmitted. This light intensity is sufficiently bright to be visually recognized by humans.

The light-shielding film BM is also formed in a frame shape at the peripheral portion, and its pattern is a pattern shown in FIG.
Are formed continuously with the pattern of the matrix section shown in FIG.

<< Color Filter FIL >> The color filter FIL is formed in a stripe shape by repeating red, green, and blue at positions facing the pixels. The color filter FIL is formed so as to overlap the edge portion of the light shielding film BM.

In the present invention, the plane layout of the overlapping portion is defined. Details will be described later.

The color filter FIL can be formed, for example, as follows. First, the upper transparent glass substrate SU
A dye base such as an acrylic resin is formed on the surface of B2, and the dye base other than the red filter formation region is removed by photolithography. Thereafter, the dyed base material is dyed with a red dye and subjected to a fixing treatment to form a red filter R. Next, the green filter G,
Blue filters B are sequentially formed.

<< Overcoat Film OC >> The overcoat film OC is provided to prevent the dye of the color filter FIL from leaking to the liquid crystal LC, and to flatten the steps formed by the color filter FIL and the light shielding film BM. The overcoat film OC is formed of, for example, a transparent resin material such as an acrylic resin or an epoxy resin.

[0120] The liquid crystal layer and the polarizing plate Subsequently, the liquid crystal layer, orientation film, described polarizing plate or the like.

<< Liquid Crystal Layer >> As the liquid crystal material LC, the dielectric anisotropy Δ △ is positive and the value is 13.2, and the refractive index anisotropy Δn
Is 0.081 (589 nm, 20 ° C.), a dielectric anisotropy Δ △ is negative and the value is −7.3, and a refractive index anisotropy Δn is 0.053 (589 nm, 20 ° C.). The nematic liquid crystal of C) was used.

The thickness (gap) of the liquid crystal layer was more than 2.8 μm and less than 4.5 μm when the dielectric anisotropy Δε was positive.
This is because the retardation Δn · d exceeds 0.25 μm.
When it is less than 32 μm, a dielectric constant characteristic having almost no wavelength dependence within the visible light range is obtained, and most of the liquid crystal having a positive dielectric anisotropy Δ △ has a birefringence anisotropy Δn of 0. 0.07 or more
This is because it is less than 09.

On the other hand, when the dielectric anisotropy Δ △ was negative, the thickness (gap) of the liquid crystal layer was set to more than 4.2 μm and less than 8.0 μm. This is because, like the liquid crystal having a positive dielectric anisotropy Δε, the retardation Δn · d exceeds 0.25 μm by 0.32 μm.
Most of the liquid crystal having a negative dielectric anisotropy Δ △ has a birefringence anisotropy Δn of more than 0.04 to suppress the dielectric anisotropy Δ △ is negative.
This is because it is less than 6.

Further, the maximum transmittance can be obtained when the liquid crystal molecules are rotated by 45 ° from the rubbing direction to the electric field direction by a combination of an alignment film and a polarizing plate described later. The thickness (gap) of the liquid crystal layer is controlled by polymer beads.

The liquid crystal material LC is not particularly limited as long as it is a nematic liquid crystal. Dielectric anisotropy △ ε
The larger the value, the lower the driving voltage, and the smaller the refractive index anisotropy Δn, the smaller the thickness (gap) of the liquid crystal layer.
Can be made thicker, the liquid crystal filling time can be shortened, and the gap variation can be reduced.

<< Orientation Film >> Polyimide is used as the orientation film ORI. The rubbing direction RDR is parallel to each other between the upper and lower substrates, and the angle φLC between the applied electric field direction EDR and the angle φLC.
Is 75 °. FIG. 12 shows the relationship.

The rubbing direction RDR and the applied electric field direction E
The angle with DR is 45 ° or more and less than 90 ° when the dielectric anisotropy △ ε of the liquid crystal material is positive, and is more than 0 ° and 45 ° or less when the dielectric anisotropy △ ε is negative. Is fine.

<< Polarizing Plate >> As the polarizing plate POL, G1220DU (trade name) manufactured by Nitto Denko Corporation was used. As shown in FIG. 10, the polarization transmission axis MAX1 of the lower polarizing plate POL1 was used.
With the rubbing direction RDR, and the upper polarizer POL
The polarization transmission axis MAX2 is orthogonal to it.

As a result, it is possible to obtain a normally closed characteristic in which the transmittance increases as the voltage applied to the pixel of the present invention (the voltage between the pixel electrode PX and the counter electrode CT) increases.

Further, in the liquid crystal display device referred to as the in-plane switching method disclosed in the present invention, when a high potential such as static electricity is applied from the outside of the surface on the upper substrate SUB2 side, display abnormality occurs. . Therefore, a layer of a transparent conductive film having a sheet resistance of 1 × 10 ⁸ Ω / □ or less is formed further above or on the surface of the upper polarizing plate POL2, or a sheet resistance of 1 × is provided between the polarizing plate and the transparent substrate. I of 10 ⁸ Ω / □ or less
Forming a layer of a transparent conductive film such as TO, or mixing conductive particles such as ITO, SnO ₂ , and In ₂ O _{3 with} the adhesive layer of the polarizing plate to reduce the sheet resistance to 1 × 10 ⁸ Ω / □ or less. It becomes necessary. Regarding this measure, it is not publicly known, but in Japanese Patent Application No. 7-264443 filed by the same applicant,
There is a detailed description of the improvement of the shield function.

<< Configuration around Matrix >> FIG. 13 shows a display panel PNL including upper and lower glass substrates SUB1 and SUB2.
2 is a plan view of a main part around a matrix (AR) of FIG. FIG. 14 shows an external connection terminal GTM to which a scanning circuit is connected on the left side.
It is sectional drawing of a vicinity.

In the manufacture of this panel, if the size is small, a plurality of devices are simultaneously processed on a single glass substrate and then divided in order to improve the throughput. If the size is large, manufacturing equipment is shared. For each type, a glass substrate of a standardized size is processed and then reduced to a size suitable for each type. In each case, the glass is cut after passing through a single process.

FIGS. 13 and 14 show examples of the latter.
13 and 14, the upper and lower substrates SUB1 and SUB2 are used.
LN indicates the edge of both substrates before cutting. In any case, in the completed state, the external connection terminal group T
The size of the upper substrate SUB2 is limited to the inside of the lower substrate SUB1 so that g, Td, and the terminal CTM are present (the upper side and the left side in the figure) so as to expose them.

The terminal groups Tg and Td are respectively a scanning circuit connection terminal GTM and a video signal circuit connection terminal DT described later.
M and a plurality of lead wiring portions are collectively named for a unit of a tape carrier package TCP (see FIGS. 15 and 16) on which the integrated circuit chip CHI is mounted.

The lead wiring from the matrix section of each group to the external connection terminal section is inclined as approaching both ends. This is because the display panel P is set in the arrangement pitch of the package TCP and the connection terminal pitch in each package TCP.
This is for adjusting to the terminals DTM and GTM of the NL.

The counter electrode terminal CTM is connected to the counter electrode CT.
Is a terminal for applying a counter voltage from the outside. The counter electrode signal line CL in the matrix portion is connected to a scanning circuit terminal GTM.
, And the common voltage signal lines are grouped together by a common bus line CB to form a common electrode terminal CT
M.

Between the transparent glass substrates SUB1 and SUB2, along the edge thereof, except for the liquid crystal filling port INJ, the liquid crystal L
A seal pattern SL is formed so as to seal C.
The sealing material is made of, for example, an epoxy resin.

The layers of the alignment films ORI1 and ORI2 are formed inside the seal pattern SL. Polarizing plates POL1, P
OL2 is formed on the outer surfaces of the lower transparent glass substrate SUB1 and the upper transparent glass substrate SUB2, respectively.

The etching LC is sealed in a region partitioned by the seal pattern SL between the lower alignment film ORI1 and the upper alignment film ORI2 for setting the direction of the liquid crystal molecules.
The lower alignment film ORI1 is formed above the protective film PSV1 on the lower transparent glass substrate SUB1 side.

In this liquid crystal display device, various layers are separately stacked on the lower transparent glass substrate SUB1 side and the upper transparent glass substrate SUB2 side, and the seal pattern SL is formed on the substrate SUB2.
Side, the lower transparent glass substrate SUB1 and the upper transparent glass substrate SUB2 are overlapped with each other to form a seal pattern SL
The liquid crystal LC is injected from the opening INJ, the inlet INJ is sealed with an epoxy resin or the like, and the upper and lower substrates are cut to be assembled.

<< Equivalent Circuit of Entire Display Device >> FIG. 16 is a schematic explanatory diagram of peripheral circuits of a liquid crystal display device according to the present invention.
As shown in the figure, the liquid crystal display substrate is constituted by a set of a plurality of pixels in which an image display unit is arranged in a matrix,
Each pixel is configured to independently control the modulation of transmitted light from a backlight disposed behind the liquid crystal display substrate.

An active pixel area is provided on an active matrix substrate SUB1, which is one of the components of the liquid crystal display substrate.
The gate signal line GL and the counter voltage signal line CL, which extend in the x direction (row direction) and are arranged in parallel in the y direction (column direction), extend in the y direction while being insulated from the AR, and extend in the x direction. The provided drain signal line DL is formed.

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

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

The vertical scanning circuit V and the video signal driving circuit H are supplied with power from the liquid crystal driving 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. It is supposed to be.

<< Driving Method >> FIG. 17 is a driving waveform diagram of the liquid crystal display device of the present invention. The opposite voltage is VCH and VCL.
Value AC rectangular wave and the scanning signal VG
(I-1) The non-selection voltage of VG (i) is changed by two 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 of 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.

<< Function of Storage Capacitance Cstg >> Storage Capacitance Cs
tg is written to the pixel (thin film transistor TFT
Is provided for long storage of video information (after the power is turned off).

In the method of applying an electric field parallel to the substrate surface used in the present invention, unlike the method of applying the electric field perpendicular to the substrate surface, the capacitance (the so-called liquid crystal capacitance) formed by the pixel electrode and the counter electrode is different. Since there is almost no storage, the storage Cstg is an essential component.

The storage capacitor Cstg also functions to reduce the effect of the gate potential change ΔVg on the pixel electrode potential Vs when the thin film transistor TFT switches. This situation is represented by the following equation.

ΔVs = [Cgs / (Cgs + Cstg +
Cpix)] × ΔVg where Cgs is a parasitic capacitance formed between the gate electrode GT and the source electrode SDI of the thin film transistor TFT,
Cpix represents a capacitance formed between the pixel electrode PX and the counter electrode CT, and ΔVs represents a change in pixel electrode potential due to ΔVg, a so-called feedthrough voltage.

The change ΔVs causes a DC component applied to the liquid crystal LC, but the value can be reduced as the storage capacitance Cstg is increased.

The reduction of the DC component applied to the liquid crystal LC is as follows.
It is possible to improve the life of the liquid crystal LC and reduce so-called burn-in in which a previous image remains when the liquid crystal display screen is switched.

As described above, since the gate electrode GT is made large so as to completely cover the i-type semiconductor layer AS, the area of overlap with the source electrode SDI and the drain electrode SD2 increases, and therefore the parasitic capacitance Cgs increases. The pixel electrode potential Vs has an adverse effect of being easily affected by the gate (scanning) signal Vg. However, the storage capacity Cs
By providing tg, this disadvantage is also eliminated.

<< Manufacturing Method >> Next, a method of manufacturing the liquid crystal display device on the substrate SUB1 side will be described.

FIG. 18, FIG. 19 and FIG. 20 are explanatory views of the manufacturing process of the liquid crystal display device according to the present invention. In FIG. 18, the central letter is the abbreviation of the process name, and the left side in FIG. The right side of the thin film transistor TFT portion shown in the drawing shows the flow of processing viewed from the cross-sectional shape near the gate terminal. Also,
Except for Step B and Step D, Step A to Step I are divided corresponding to each photographic process (photolithography), and any cross-sectional view of each process is a stage where the processing after the photographic process is completed and the photoresist is removed. Is shown.

In the present invention, photographic processing refers to a series of operations from application of a photoresist, through selective exposure using a mask to development of the photoresist, and a repetitive description will be omitted. Description will be given below according to the divided steps.

Step A (FIG. 18) A 300 nm thick Al-Pd or Al-Pd film is formed on a lower transparent glass substrate SUB1 made of AN635 glass (trade name).
Conductive film g made of W, Al-Ta, Al-Ti-Ta, etc.
1 is provided by sputtering. After the photographic processing, the conductive film g1 is selectively etched with a mixed acid solution of phosphoric acid, acid and glacial acetic acid. Thereby, the gate electrode GT, the scanning signal line GL, the counter electrode CT, the counter voltage signal line CL, and the electrode PL
1, gate terminal GTM, first conductive layer of common bus line CB, first conductive layer of counter electrode terminal CTM, gate terminal GT
An anodizing bus line SHg (not shown) connecting M and an anodizing pad (not shown) connected to the anodizing bus line SHg are formed.

Step B (FIG. 18) After the formation of the anodic oxidation mask AO by direct writing, a solution in which 3% tartaric acid was adjusted to PH 6.25 ± 0.05 with ammonia and diluted 1: 9 with ethylene glycol solution was used. The substrate SUB1 is immersed in an anodic oxidizing solution to adjust the formation current density to 0.5 mA / cm ² (constant current formation).

Next, anodic oxidation is performed until the formation voltage 125 V necessary for obtaining a predetermined alumina (Al ₂ O ₃ ) film thickness is reached. Thereafter, it is desirable to maintain this state for several tens of minutes (constant voltage formation). This is a uniform Al ₂ O
_This is important for obtaining _three films. Thereby, the conductive film g1 is anodized, and the gate electrode GT and the scanning signal line G
L, counter electrode CT, counter voltage signal line CL and electrode PL1
An anodic oxide film AOF having a thickness of 180 bnm is formed thereon.

Step C (FIG. 18) A transparent conductive film g2 made of an ITO film having a thickness of 140 nm is provided by sputtering. After the photographic processing, the transparent conductive film g2 is selectively etched with a mixed acid solution of hydrochloric acid and nitric acid as an etchant, thereby forming the uppermost layer of the gate terminal GTM, the drain terminal DTM, and the second conductive film of the counter electrode terminal CTM. I do.

Step D (FIG. 19) Ammonia gas, silane gas, and nitrogen gas are introduced into the plasma CVD apparatus to provide a 220-nm-thick Si nitride film, and silane gas and hydrogen gas are introduced into the plasma CVD apparatus to form a film. After an i-type amorphous Si film having a thickness of 200 nm is provided, a silane gas, a hydrogen gas, and a phosphine gas are introduced into a plasma CVD apparatus to form an N (+)-type amorphous Si film having a thickness of 30 nm.

Step E (FIG. 19) After the photographic processing, the N (+)-type amorphous Si film and the i-type amorphous Si film are selectively etched using SF6 as a dry etching gas, whereby i An island of the type semiconductor layer AS is formed.

Step F (FIG. 19) After the photographic processing, the Si nitride film is selectively etched using SF6 as a dry etching gas.

Step G (FIG. 20) A conductive film d1 made of Cr and having a thickness of 60 nm is provided by sputtering, and an Al-P film having a thickness of 400 nm is further formed.
A conductive film d2 made of d, Al-Si, Al-Ta, Al-Ti-Ta, or the like is provided by sputtering. After the photographic processing, the conductive film d2 is etched with the same liquid as in Step A,
The conductive film d1 is etched with a ceric ammonium nitrate solution, and the video signal line DL, the source electrode SD1, the drain electrode SD2, the pixel electrode PX, the electrode PL2, the second conductive layer, the third conductive layer and the drain of the common bus line CB are formed. Terminal D
A bus line SHd (not shown) for short-circuiting TM is formed. Next, SF6 is introduced into the dry etching apparatus,
By etching the N (+) type amorphous Si film,
The N (+) type semiconductor layer d0 between the source and the drain is selectively removed.

Step H (FIG. 20) An ammonia gas, a silane gas, and a nitrogen gas are introduced into a plasma CVD apparatus to form a 500-nm-thick Si nitride film. After photographic processing, SF is used as the drain etching gas.
The protective film PSV1 is formed by selectively etching the Si nitride film by a photolithography technique using No. 6.

<< Display Panel PNL and Drive Circuit Board PCB
1 >> FIG. 21 shows the display panel PNL shown in FIG. 13 and FIG.
FIG. 2 is a top view showing a state in which a video signal driving circuit H and a vertical scanning circuit V are connected.

CH1 is a driving IC chip for driving the display panel PNL (the lower five are driving ICs on the vertical scanning circuit side).
Chip, drive ICs on the left side of the 10 video signal drive circuits
Chip). TCP is a tape carrier package in which the driving IC chip CH1 is mounted by a tape automated bonding (TAB) method as shown in FIGS. 14 and 15, and PCB1 is a driving circuit in which the above-described TCP, capacitors, etc. are mounted. The substrate is divided into two, one for a video signal drive circuit and one for a scan signal drive circuit.

FGP is a frame ground pad.
A spring-shaped fragment provided by cutting into the shield case SHD is soldered. FC is the lower drive circuit board PC
This is a flat cable for electrically connecting B1 to the left drive circuit board PCB1.

As shown in the figure, the flat cable FC is formed by sandwiching and supporting a plurality of lead wires (phosphor bronze material plated with Sn) with a striped polyethylene layer and a polyvinyl alcohol layer. use.

<< Connection Structure of TCP >> FIG.
FIG. 14 is a diagram showing a cross-sectional structure of a tape carrier package in which an integrated circuit chip CHI constituting a scanning signal driving circuit V and a video signal driving circuit H is mounted on a flexible wiring board, and FIG. FIG. 3 is a cross-sectional view of a main part showing a state connected to a scanning signal circuit terminal GTM.

In the figure, TTB is an input terminal / wiring portion of the integrated circuit CHI, and TTM is an output terminal / wiring portion of the integrated circuit CHI, which is made of, for example, Cu. The bonding pads PAD of the integrated circuit CHI are connected to the leads by a so-called face-down bonding method.

The outer ends (commonly called outer leads) of the terminals TTB and TTM are respectively connected to the semiconductor integrated circuit chips CH
Corresponds to input and output of I, CRT /
Anisotropic conductive film AC for TFT conversion circuit / power supply circuit SUP
F connects to the liquid crystal display panel PNL.

The package TCP is connected to the panel so that the leading end thereof covers the protective film PSV1 exposing the connection terminal GTM on the panel PNL side. Therefore,
Since the outer connection terminal GTM (DTM) is covered with at least one of the protective film PSV1 and the package TCP, the outer connection terminal GTM (DTM) is resistant to electric contact.

BF1 is a base film made of polyimide or the like, and SRS is a solder resist film for masking so that the solder does not stick to unnecessary portions during soldering. The gap between the upper and lower glass substrates outside the seal pattern SL is protected by an epoxy resin EPX or the like after cleaning, and the space between the package TCP and the upper substrate SUB2 is further filled with a silicon resin SIL to multiplex protection.

<< Drive Circuit Board PCB2 >> Drive Circuit Board P
The CB2 has electronic components such as an IC, a capacitor, and a resistor mounted thereon. The drive circuit board PCB2 includes a power supply circuit for obtaining a plurality of divided and stabilized voltage sources from one voltage source, and a CR (Crystal Control Unit) from a host (upper processing unit).
A circuit SUP including a circuit for converting information for T (cathode ray tube) into information for a TFT liquid crystal display device is mounted. C
J is a connector connection portion to which a connector (not shown) connected to the outside is connected.

Drive circuit board PCB1 and drive circuit board PC
B2 is electrically connected by a joiner JN such as a flat cable FC.

It is needless to say that the liquid crystal display device according to the present invention can be used not only for the above-mentioned desktop monitor but also for a display device of a portable personal computer such as a notebook type.

Also, it should be noted that the present invention is not limited to the above-mentioned horizontal electric field type active matrix type liquid crystal display device, but is applicable to a vertical electric field type or simple matrix type liquid crystal display device. The present invention can be similarly applied to a method and an apparatus which do not require the liquid crystal alignment control ability.

[0181]

As described above, according to the present invention,
By fixing the liquid crystal display module to the case of the display portion without using a screw, it is possible to provide a liquid crystal display device that can cope with a case where a liquid crystal panel has a large screen by narrowing a frame. .

[Brief description of the drawings]

FIG. 1 is a plan view of a display unit for explaining a fixing structure of a liquid crystal display module in a first embodiment of a liquid crystal display device according to the present invention.

FIG. 2 is a partial sectional view taken along line AA of FIG.

FIG. 3 is a plan view of a display unit for explaining a fixing structure of a liquid crystal display module in a liquid crystal display device according to a second embodiment of the present invention.

FIG. 4 is a partial sectional view taken along the line AA of FIG. 3;

FIG. 5 is a plan view of a display unit illustrating a fixing structure of a liquid crystal display module in a liquid crystal display device according to a third embodiment of the present invention.

FIG. 6 is a partial sectional view taken along line AA of FIG. 5;

FIG. 7 is an external view of a notebook computer on which the liquid crystal display device according to the present invention is mounted.

FIG. 8 is a plan view showing one pixel of an active matrix type color liquid crystal display device of the present invention, a light shielding region of a black matrix BM, and its periphery.

9 is a cross-sectional view of the thin film transistor TFT taken along the line FF in FIG.

FIG. 10 shows a storage capacitance Cst along a section line GG in FIG. 8;
It is sectional drawing of g.

11A and 11B are a cross-sectional view of the vicinity of an electrode of one pixel and a cross-sectional view of a peripheral portion of the substrate in an image display area of a liquid crystal display substrate of a horizontal electric field type.

FIG. 12 shows a rubbing direction of an alignment film and an applied electric field direction EDR.
FIG. 4 is an explanatory diagram of an angle formed by

FIG. 13 is a plan view of a main part around a matrix of a display panel including upper and lower substrates.

FIG. 14 is a cross-sectional view near an external terminal to which a scanning circuit is connected on the left side.

FIG. 15 is an explanatory diagram of a cross-sectional structure of an output side and an input side of a gate TCP.

FIG. 16 is a schematic explanatory diagram of a peripheral circuit of a liquid crystal display device according to the present invention.

FIG. 17 is a driving waveform diagram of the liquid crystal display device of the present invention.

FIG. 18 is an explanatory diagram of the manufacturing process of the liquid crystal display device according to the present invention.

FIG. 19 is a view showing a manufacturing process of the liquid crystal display device according to the present invention;
It is explanatory drawing following 9.

FIG. 20 is a view showing a manufacturing process of the liquid crystal display device according to the present invention;
It is explanatory drawing following 0.

21 is a top view illustrating a state where the display panel PNL, the video signal driving circuit H, and the vertical scanning circuit V illustrated in FIG. 17 are connected.

FIG. 22 is a plan view of a display unit for explaining a fixing structure of a liquid crystal display module in a conventional liquid crystal display device.

FIG. 23 is a partial sectional view taken along line AA of FIG. 22;

[Explanation of symbols]

 SUB1 First substrate SUB2 Second substrate CASE Case MDL Liquid crystal display module POL1, POL2 Polarizer BL Backlight SHD1 Upper frame SHD2 Lower frame GC Rubber cushion PNL Liquid crystal panel TAB1 to TAB4 Tab ST1, ST2 Reinforcement member ALC Tab receiving hole HNG Hinges.

Claims (3)

[Claims] 1. A liquid crystal panel having a liquid crystal layer sandwiched between a pair of transparent substrates having a pixel selection electrode on at least one of them opposed to each other, and applying a voltage corresponding to a display signal to the panel. A liquid crystal display module in which a liquid crystal display module in which a driving circuit means of the above and a backlight provided on the back of the liquid crystal panel are fixed by an upper frame and a lower frame connected to the upper frame is mounted on a case constituting a display section. In the device, the liquid crystal display module includes at least one tab protruding outward on two parallel sides of one or both of the upper frame and the lower frame, and the case has a bottom surface and a bottom surface. By having at least a pair of opposed side walls formed with a facing tab receiving hole, by engaging the tab with the tab receiving hole,
A liquid crystal display device, wherein the liquid crystal display module is fixed to the case. 2. A liquid crystal panel having a liquid crystal layer sandwiched between a pair of transparent substrates having a pixel selection electrode on at least one of them opposed to each other, and applying a voltage corresponding to a display signal to the panel. A liquid crystal display module in which a liquid crystal display module in which a driving circuit means of the above and a backlight provided on the back of the liquid crystal panel are fixed by an upper frame and a lower frame connected to the upper frame is mounted on a case constituting a display section. In the device, the liquid crystal display module includes at least one tab projecting outward on two sides parallel to one or both of the upper frame and the lower frame, and the case faces the bottom surface and the bottom surface. A tab receiving hole in one of the side walls, and a side wall facing the side wall provided with the tab receiving hole and the bottom surface interposed therebetween. The liquid crystal display module has a reinforcing member fixed to the case with a support hole, and the tab of the liquid crystal display module is engaged with the tab receiving hole of the side wall and the tab receiving hole of the reinforcing member. A liquid crystal display device fixed to the case. 3. A liquid crystal panel having a liquid crystal layer sandwiched between a pair of transparent substrates having a pixel selection electrode on at least one of them opposed to each other, and applying a voltage according to a display signal to the panel. A liquid crystal display module in which a liquid crystal display module in which a driving circuit means of the above and a backlight provided on the back of the liquid crystal panel are fixed by an upper frame and a lower frame connected to the upper frame is mounted on a case constituting a display section. In the device, the liquid crystal display module includes at least one tab protruding from each of parallel sides of one or both of the upper frame and the lower frame; A pair of reinforcing members fixed to the case with tab receiving holes provided on an inner side thereof; and the liquid crystal display module is provided in the tab receiving holes of the pair of reinforcing members. The liquid crystal display module is fixed to the case by engaging a tab of a ruler.