JPH1010556A - Liquid crystal display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain the liquid crystal display device which has high display luminance by forming a thin film transistor on a gate signal line. SOLUTION: A 1st pixel electrode 5 and a 2nd pixel electrode 6 are formed of films of, for example, tin oxide, ITO, etc., and are formed preferably of films of ITO of about 1000Å in thickness and about 10μm in width formed by a sputtering method for easy patterning, high light transmissivity, and high conductivity. The 1st and 2nd pixel electrodes 5 and 6 are formed of the transparent conductive films, so the light emitted by a back light is transmitted to parts where the 1st and 2nd pixel electrodes 5 and 6 are formed among pixels. Further, a TFT(thin film transistor) 4 is formed on a gate signal 1, so the aperture rate of each pixel in a display area becomes about 55% and the aperture rate of each pixel is improved.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a liquid crystal display device mounted on a portable television, a wall-mounted television, or a portable OA device.

[0002]

2. Description of the Related Art In a conventional liquid crystal display device, liquid crystal molecules are usually sandwiched between two transparent insulating substrates (hereinafter, also simply referred to as "substrates") which are opposed to each other in parallel. It is configured so that a voltage is applied. Electrodes are formed on each of the two substrates. For example, of the two substrates, the electrodes formed on at least one of the substrates are pixel electrodes arranged in a matrix. When a voltage is selectively applied to the pixel electrode, a voltage is selectively applied to the liquid crystal molecules. The pixel electrode is provided for each pixel of the liquid crystal display device. The pixel electrode is provided with a switching element such as a transistor so that a voltage is selectively applied to each pixel electrode, and a certain voltage is applied to the pixel electrode via the switching element. The axis direction of the liquid crystal molecules in the pixel as a whole, that is, the alignment of the liquid crystal molecules is controlled, and the light transmittance is controlled for each pixel.

In a conventional liquid crystal display device, when a voltage is applied between electrodes formed on two substrates, the orientation of liquid crystal molecules is controlled by an electric field generated in a direction perpendicular to the substrates. Such display modes are mainly used. An example of the display mode is a twist net (TN) mode. However, when the orientation of the liquid crystal molecules is controlled by such a display mode, the viewing angle at which the contrast ratio between the pixels can be maintained at a certain value or more is narrow. Sometimes it is a problem.

In order to solve such a problem, there has been proposed a display mode in which the orientation of liquid crystal molecules is controlled by an electric field generated in a direction horizontal to the substrate. The display mode is R. R. Kiefer et al.
et al. ) "In-Plane Switching of Nemetic Liquid Crystal"
electronic Liquid Crystals Japan Display 92 (JAPAN DISPL)
AY 92) Hiroshima " 547-550. In this specification, such a display mode is referred to as I
Called PS mode.

Next, as a conventional liquid crystal display device in which the alignment of liquid crystal molecules is controlled using the IPS mode,
A liquid crystal display device described in JP-A-7-128683 will be described with reference to the drawings.

FIG. 8 is an explanatory view showing an example of a conventional liquid crystal display device. FIG. 8A is an explanatory plan view illustrating one pixel among a plurality of pixels formed in a matrix in a display area of a liquid crystal display device. FIG.
It is a section explanatory view showing the EE line section of (a). FIG.
FIG. 9C is an explanatory diagram illustrating an electrical equivalent circuit of FIG. FIG. 8A shows the surface of one of the two transparent insulating substrates facing in parallel with each other,
The vicinity of the surface on the side facing the other transparent insulating substrate is shown. 8, reference numeral 10 denotes a transparent insulating substrate, 1 denotes a gate signal line provided on the transparent insulating substrate 10, 9 denotes an insulating film formed on the transparent insulating substrate 10 and the gate signal line 1, and 2 denotes an insulating film. Source signal lines 3 are formed so as to be orthogonal to the gate signal lines 1 with the film 9 interposed therebetween.
A common signal line 14 is formed in parallel with a thin film transistor (hereinafter referred to as “T”) to which a gate signal transmitted through the gate signal line 1 is input.
Reference numeral 15 denotes a first pixel electrode connected to the TFT 14, and 16 denotes a second pixel electrode connected to the common signal line 3 through a contact hole 8 formed in the insulating film 9. In FIG. 8A, the insulating film 9 and the transparent insulating substrate 10 are not shown.

The first pixel electrode 15 is formed on the insulating film 9, and forms a storage capacitor between the common signal line 3 and the storage capacitor forming section 7. Further, the first pixel electrode 15 and the second pixel electrode 16 are formed of a metal film made of titanium or aluminum. The TFT 14 includes a gate electrode, a gate insulating film formed on the gate electrode, a semiconductor layer formed on the gate insulating film, a semiconductor layer formed on the semiconductor layer, and And a source electrode and a drain electrode respectively formed on a part of the. The gate electrode is connected to a gate signal line 1, the source electrode is connected to a source signal line 2, and the drain electrode is a first pixel electrode 15
Connected to.

The switching of the TFT 14 is controlled by a gate signal transmitted through the gate signal line 1,
The source signal transmitted via the source signal line 2 is the TF
The potential is applied to the first pixel electrode 15 via T14 to control the potential of the first pixel electrode 15. By controlling the switching of the TFT 14 by the gate signal, a source signal is selectively applied only to a desired first pixel electrode among the first pixel electrodes formed for each pixel, and a desired first A voltage of a desired magnitude is selectively applied only to the pixel electrodes of the above. In addition, the source signal has a voltage value of a desired magnitude necessary for displaying a desired image on a display area of the liquid crystal display device.

In FIG. 8C, reference numeral 11 denotes liquid crystal molecules, and the orientation of the liquid crystal molecules 11 is controlled by the magnitude and polarity of an electric field generated between the first pixel electrode 15 and the second pixel electrode 16. You. That is, how much light passes through the pixel is controlled by the magnitude and polarity of the electric field. Reference numeral 12 denotes a storage capacitor formed between the first pixel electrode 15 and the common signal line 3.

Since the conventional liquid crystal display device has the above-described structure, a gate signal transmitted through the gate signal line 1 can be applied to a desired first pixel electrode.
An electric field generated between the first pixel electrode and the second pixel electrode in a direction horizontal to the transparent insulating substrate can selectively control the orientation of liquid crystal molecules for each pixel. Thus, a desired image can be displayed on the display area of the liquid crystal display device.

[0011]

SUMMARY OF THE INVENTION In a liquid crystal display device, two transparent insulating substrates, liquid crystal molecules sandwiched between the two transparent insulating substrates, and a surface of the two transparent insulating substrates. Since the panel itself formed of signal lines, TFTs, and the like is a non-light emitting element, a backlight is usually arranged on the back surface of one of the two transparent insulating substrates, and the backlight Illuminates the panel with light to display a desired image in the display area of the panel. One of the important display performances of the liquid crystal display device is display luminance, that is, brightness of a display area of the liquid crystal display device. Recently, there has been a demand for lower power consumption of liquid crystal display devices, and therefore, the brightness of the backlight is limited. Therefore, in order to increase the display brightness of the liquid crystal display device, it is necessary to increase the amount of light transmitted through the panel out of the light emitted from one surface of the panel, that is, to improve the transmittance of the panel. Is done. The light transmittance of the panel is directly related to the aperture ratio of each pixel in the display area of the panel. The aperture ratio indicates a ratio of an effective light transmitting region to a pixel unit area.

In a conventional liquid crystal display device, the first pixel electrode and the second pixel electrode are formed of a metal film made of titanium or aluminum. Therefore, the aperture ratio of each pixel in the display area related to the display luminance of the liquid crystal display device is the first.
Greatly depends on the widths of the pixel electrode and the second pixel electrode. Ideally, the widths of the first pixel electrode and the second pixel electrode are desirably as narrow as possible, but in order to prevent disconnection between the first pixel electrode and the second pixel electrode, 10
The width of about μm is the limit. In addition, the TFT also causes a reduction in the aperture ratio of each pixel in the display area.
Occupies a part of the surface area of the pixel, which also causes the display luminance of the liquid crystal display device to decrease.

For example, a display area of a liquid crystal display device for a personal computer has a length of about 300 μm and a width of about 100 μm.
Here, the first pixel electrode and the second pixel electrode are set to 10 μm.
If it is about m, the aperture ratio of each pixel in the display area is about 25%. The reduction in the aperture ratio due to the TFT is about 5%. On the other hand, a conventional liquid crystal display device controlled by the TN mode has a display area having an aperture ratio of 50% or more.

Therefore, in the liquid crystal display device controlled in the IPS mode, it is an object to increase the display luminance of the liquid crystal display device by increasing the aperture ratio of each pixel in the display area.

[0015]

According to the liquid crystal display device of the present invention, two transparent insulating substrates opposing each other in parallel, a gate signal line formed on one of the transparent insulating substrates, An insulating film formed on the line, a source signal line orthogonal to the gate signal line through the insulating film, a common signal line formed in parallel with the gate signal line, and the gate signal line. A thin film transistor to which a transmitted gate signal is input; a first pixel electrode connected to the thin film transistor; and a second pixel electrode connected to the common signal line.
Pixel electrodes, and liquid crystal molecules sandwiched between the two transparent insulating substrates. When the gate signal is input, the switching of the thin film transistor is controlled and transmitted through the source signal line. A source signal is applied to the first pixel electrode via the thin film transistor to control the potential of the first pixel electrode, and a common signal transmitted through the common signal line is applied to the second pixel. An electric field generated between the first pixel electrode and the second pixel electrode in a horizontal direction on the surface of the transparent insulating substrate is controlled by being applied to the electrodes, so that the liquid crystal molecules are driven. Liquid crystal display device,
The thin film transistor is formed on the gate signal line.

In the liquid crystal display device of the present invention, two transparent insulating substrates opposing each other in parallel, a gate signal line formed on one of the transparent insulating substrates, and a film formed on the gate signal line. An insulating film, a source signal line orthogonal to the gate signal line through the insulating film, a common signal line formed in parallel with the gate signal line, and a gate signal transmitted through the gate signal line. A thin film transistor to be input, a first pixel electrode connected to the thin film transistor, a second pixel electrode connected to the common signal line,
The liquid crystal molecules are sandwiched between the two transparent insulating substrates, and the switching of the thin film transistor is controlled by the input of the gate signal, and the source signal transmitted through the source signal line is the source signal. A potential of the first pixel electrode is controlled by being applied to the first pixel electrode via a thin film transistor, and a common signal transmitted through the common signal line is applied to the second pixel electrode. Accordingly, an electric field generated in the horizontal direction on the surface of the transparent insulating substrate between the first pixel electrode and the second pixel electrode is controlled, and the liquid crystal molecules are driven. Wherein the first pixel electrode is made of a transparent conductive film.

It is preferable that the thin film transistor is formed on the gate signal line because the aperture ratio can be further increased.

In the liquid crystal display device of the present invention, two transparent insulating substrates opposing each other in parallel, a gate signal line formed on one of the transparent insulating substrates, and a film formed on the gate signal line. An insulating film, a source signal line orthogonal to the gate signal line through the insulating film, a common signal line formed in parallel with the gate signal line, and a gate signal transmitted through the gate signal line. A thin film transistor to be input, a first pixel electrode connected to the thin film transistor, a second pixel electrode connected to the common signal line,
The liquid crystal molecules are sandwiched between the two transparent insulating substrates, and the switching of the thin film transistor is controlled by the input of the gate signal, and the source signal transmitted through the source signal line is the source signal. A potential of the first pixel electrode is controlled by being applied to the first pixel electrode via a thin film transistor, and a common signal transmitted through the common signal line is applied to the second pixel electrode. Thereby, an electric field generated in the horizontal direction on the surface of the transparent insulating substrate between the first pixel electrode and the second pixel electrode is controlled, and the liquid crystal molecules are driven. Wherein the second pixel electrode is made of a transparent conductive film.

It is preferable that the thin film transistor is formed on the gate signal line because the aperture ratio can be further increased.

In the liquid crystal display device of the present invention, two transparent insulating substrates opposing each other in parallel, a gate signal line formed on one of the transparent insulating substrates, and a film formed on the gate signal line. An insulating film, a source signal line orthogonal to the gate signal line through the insulating film, a common signal line formed in parallel with the gate signal line, and a gate signal transmitted through the gate signal line. A thin film transistor to be input, a first pixel electrode connected to the thin film transistor, a second pixel electrode connected to the common signal line,
The liquid crystal molecules are sandwiched between the two transparent insulating substrates, and the switching of the thin film transistor is controlled by the input of the gate signal, and the source signal transmitted through the source signal line is the source signal. A potential of the first pixel electrode is controlled by being applied to the first pixel electrode via a thin film transistor, and a common signal transmitted through the common signal line is applied to the second pixel electrode. Thereby, an electric field generated in the horizontal direction on the surface of the transparent insulating substrate between the first pixel electrode and the second pixel electrode is controlled, and the liquid crystal molecules are driven. Wherein the first pixel electrode and the second pixel electrode are made of a transparent conductive film.

It is preferable that the thin film transistor is formed on the gate signal line because the aperture ratio can be further increased.

[0022]

Next, a liquid crystal display device of the present invention will be described with reference to the drawings.

Embodiment 1 FIG. 1 is an explanatory view showing one embodiment of the liquid crystal display device of the present invention. FIG. 1A is an explanatory plan view showing one pixel among a plurality of pixels formed in a matrix in a display area of a liquid crystal display device. FIG.
FIG. 3A is a cross-sectional explanatory view illustrating a cross section taken along line AA of FIG. FIG.
FIG. 2C is an explanatory diagram showing an electrical equivalent circuit of FIG. In FIG. 1, 1 is a gate signal line, 2 is a source signal line, 3 is a common signal line, 4 is a TFT, 9 is an insulating film, 1
0 denotes a transparent insulating substrate, 15 denotes a first pixel electrode, and 16 denotes a second pixel electrode. In FIG. 1A, the insulating film 9 and the transparent insulating substrate 10 are not shown. FIG.
In (c), reference numeral 11 denotes liquid crystal molecules, and reference numeral 12 denotes a storage capacitor formed between the first pixel electrode 15 and the common signal line 3.

In the liquid crystal display device of the present invention, two transparent insulating substrates opposing each other in parallel, a gate signal line 1 formed on one transparent insulating substrate 10, and An insulating film 9 to be formed; a source signal line 2 orthogonal to the gate signal line 1 through the insulating film 9; a common signal line 3 formed in parallel with the gate signal line 1; A TFT 4 to which a gate signal transmitted via the signal line 1 is input; a first pixel electrode 15 connected to the TFT; a second pixel electrode 16 connected to the common signal line 3; And liquid crystal molecules (not shown) sandwiched between two transparent insulating substrates. FIG.
(A) of the two transparent insulating substrates opposed to each other in parallel with each other shows the vicinity of the surface of one transparent insulating substrate 10 on the side facing the other transparent insulating substrate. I have.

The switching of the TFT 4 is controlled by the input of the gate signal, and a source signal transmitted through the source signal line 1 is applied to the first pixel electrode 15 through the TFT 4 to be switched. The potential of the first pixel electrode 15 is controlled, and a common signal transmitted via the common signal line 3 is applied to the second pixel electrode 16 so that the first pixel electrode 15 and the An electric field is generated in the horizontal direction on the surface of the transparent insulating substrate between the second pixel electrode 16 and the alignment of the liquid crystal molecules is controlled. That is, the liquid crystal molecules are driven by the electric field. The common signal line 3 is formed on the transparent insulating substrate 10 like the gate signal line 1.

In the present embodiment, the TFT 4 is formed on the gate signal line 1 (see FIG. 1A). Therefore, the first pixel electrode 15 and the second pixel electrode 16 can be formed in the portion where the TFT is formed in the pixel of the conventional liquid crystal display device, and each of the display regions of the liquid crystal display device of the present invention is formed. The aperture ratio of the pixel is about 30%.

Embodiment 2 Next, another embodiment of the liquid crystal display device of the present invention will be described.

FIG. 2 is an explanatory view showing another embodiment of the liquid crystal display device of the present invention. FIG. 2A is an explanatory plan view showing one pixel among a plurality of pixels formed in a matrix in a display area of the liquid crystal display device. FIG.
FIG. 2B is an explanatory cross-sectional view illustrating a cross section taken along line AA of FIG. FIG. 2C is an explanatory diagram showing an electrical equivalent circuit of FIG. 2, the same reference numerals are used for the same portions as those shown in FIG. 8 showing the conventional liquid crystal display device.

The difference between the conventional liquid crystal display device and the liquid crystal display device of the present embodiment is that the first pixel electrode 5 is formed of a transparent conductive film. The first
The pixel electrode 5 is formed of, for example, a film of tin oxide or a film of indium oxide (ITO), and is formed by a sputtering method in that patterning is easy, light transmittance is high, and conductivity is high. Most preferably, it is made of an ITO film having a thickness of about 1000 ° and a width of about 10 μm. Since the first pixel electrode 5 is formed of a transparent conductive film, light emitted from the backlight can be transmitted to a portion of the pixel where the first pixel electrode 5 is formed. As a result, the aperture ratio of each pixel in the display area of the liquid crystal display device is 4
It is about 0%.

The TF of the liquid crystal display device shown in FIG.
T may be formed on the gate signal line 1 as in the first embodiment. FIG. 3 shows a liquid crystal display device having such a structure. FIG. 3A is an explanatory plan view showing one pixel among a plurality of pixels formed in a matrix in a display area of the liquid crystal display device. FIG. 3 (b) is a view of B in FIG. 3 (a).
It is sectional explanatory drawing which shows the -B line cross section. FIG. 3C is an explanatory diagram showing an electrical equivalent circuit of FIG. In FIG. 3, the same portions as those shown in FIG. 2 are denoted by the same reference numerals.

In the liquid crystal display device shown in FIG. 3, since the first pixel electrode 5 is formed of a transparent conductive film and the TFT 4 is formed on the gate signal line 1, the liquid crystal display device shown in FIG. The aperture ratio of each pixel in the display area is higher than that of the device. The aperture ratio of each pixel in the display area of the liquid crystal display device shown in FIG. 3 is about 45%.

Embodiment 3 Next, another embodiment of the liquid crystal display device of the present invention will be described.

FIG. 4 is an explanatory view showing another embodiment of the liquid crystal display device of the present invention. FIG. 4A is an explanatory plan view showing a certain pixel among a plurality of pixels formed in a matrix in a display area of the liquid crystal display device. FIG.
FIG. 4B is an explanatory cross-sectional view showing a cross section taken along line CC of FIG. FIG. 4C is an explanatory diagram showing an electrical equivalent circuit of FIG. 4, the same reference numerals are used for the same portions as those shown in FIG. 8 showing the conventional liquid crystal display device.

The difference between the conventional liquid crystal display device and the liquid crystal display device of the present embodiment is that the second pixel electrode 6 is formed of a transparent conductive film. The second pixel electrode 6 is made of, for example, a tin oxide film or an ITO film, and has a thickness formed by a sputtering method in that it is easy to pattern, has high light transmittance, and has high conductivity. Most preferably, it is made of an ITO film having a thickness of about 1000 ° and a width of about 10 μm. Since the second pixel electrode 6 is formed of a transparent conductive film, light emitted from the backlight can be transmitted to a portion of the pixel where the second pixel electrode 6 is formed. As a result, the aperture ratio of each pixel in the display area of the liquid crystal display device is about 35%.

The TF of the liquid crystal display shown in FIG.
T may be formed on the gate signal line 1 as in the first embodiment. FIG. 5 shows a liquid crystal display device having such a structure. FIG. 5A is an explanatory plan view showing one pixel among a plurality of pixels formed in a matrix in a display area of a liquid crystal display device. FIG. 5 (b) is a view of C in FIG. 5 (a).
It is sectional explanatory drawing which shows the -C line cross section. FIG. 5C is an explanatory diagram showing an electrical equivalent circuit of FIG. In FIG. 5, the same portions as those shown in FIG. 4 are denoted by the same reference numerals.

In the liquid crystal display device shown in FIG. 5, since the second pixel electrode 6 is formed of a transparent conductive film and the TFT 4 is formed on the gate signal line 1, the liquid crystal display device shown in FIG. The aperture ratio of each pixel in the display area is higher than that of the device. The aperture ratio of each pixel in the display area of the liquid crystal display device shown in FIG. 5 is about 40%.

Embodiment 4 Next, another embodiment of the liquid crystal display device of the present invention will be described.

FIG. 6 is an explanatory view showing another embodiment of the liquid crystal display device of the present invention. FIG. 6A is an explanatory plan view showing one pixel among a plurality of pixels formed in a matrix in a display area of the liquid crystal display device. FIG.
FIG. 6B is a cross-sectional explanatory view showing a cross section taken along line DD of FIG. FIG. 6C is an explanatory diagram showing an electrical equivalent circuit of FIG. 6A. 6, the same reference numerals are used for the same portions as those shown in FIG. 8 showing the conventional liquid crystal display device.

The difference between the conventional liquid crystal display device and the liquid crystal display device of the present embodiment is that the first pixel electrode 5 and the second pixel electrode 6 are formed of a transparent conductive film. It is. The first pixel electrode 5 and the second pixel electrode 6 are made of, for example, a tin oxide film or an ITO film, and are easily patterned, have high light transmittance, and have high conductivity. Most preferably, it is formed of an ITO film having a thickness of about 1000 ° and a width of about 10 μm formed by sputtering. Since the first pixel electrode 5 and the second pixel electrode 6 are formed of a transparent conductive film, a portion of the pixel where the first pixel electrode 5 and the second pixel electrode 6 are formed has a backlight. Can be transmitted through the device. As a result, the aperture ratio of each pixel in the display area of the liquid crystal display becomes about 50%.

The TF of the liquid crystal display device shown in FIG.
T may be formed on the gate signal line 1 as in the first embodiment. FIG. 7 shows a liquid crystal display device having such a structure. FIG. 7A is an explanatory plan view showing one pixel among a plurality of pixels formed in a matrix in a display area of a liquid crystal display device. FIG. 7 (b) is a diagram of D in FIG. 7 (a).
It is sectional explanatory drawing which shows the -D line cross section. FIG. 7C is an explanatory diagram showing an electrical equivalent circuit of FIG. 7A. 7, the same parts as those shown in FIG. 6 are denoted by the same reference numerals.

In the liquid crystal display device shown in FIG. 7, the first pixel electrode 5 and the second pixel electrode 6 are formed of a transparent conductive film, and the TFT 4 is formed on the gate signal line 1. The aperture ratio of each pixel in the display area is higher than in the liquid crystal display device shown in FIG. The aperture ratio of each pixel in the display area of the liquid crystal display device shown in FIG. 7 is about 55%.

In the first to fourth embodiments, the transparent insulating substrate is preferably made of a quartz substrate or a glass substrate, most preferably a glass substrate having a thickness of about 1 mm in terms of low cost. The signal line is made of a material such as a chromium (Cr) film, an aluminum (Al) film, or a tantalum (Ta) film, and is made of a film having a thickness of about 3000 mm and a width of about 20 μm in terms of good flatness. It is most preferable that the insulating film is made of a silicon nitride (SiN) film or a silicon oxide (SiO ₂ ) film.
It is most preferable that the source signal line is made of an ITO film, a Cr film, or an Al film.
Thickness 4000 formed by sputtering because of high conductivity
Most preferably, the common signal line is made of a material such as a Cr film, an Al film or a Ta film, and has a thickness of about 3000 mm in terms of good flatness. And most preferably a film having a width of about 20 μm.
Or it is preferably a channel-etch type TFT,
It is most preferable to use a channel-etch type TFT from the viewpoint of reducing the number of manufacturing steps.

[0043]

Since the liquid crystal display device of the present invention is constructed as described above, it has the following effects.

In the liquid crystal display device of the present invention, a thin film transistor is formed on the gate signal line, so that the surface area of a portion through which light can be transmitted in each pixel can be increased, and a liquid crystal display device having high display luminance can be obtained. You can get.

In the liquid crystal display device according to the present invention, since the first pixel electrode is made of a transparent conductive film, light can be transmitted also to the portion where the first pixel electrode is formed in each pixel, and a high display can be achieved. A liquid crystal display device having luminance can be obtained.

Further, a liquid crystal display device having higher display luminance can be obtained by forming the first pixel electrode from a transparent conductive film and forming a thin film transistor on the gate signal line.

In the liquid crystal display device of the present invention, since the second pixel electrode is made of a transparent conductive film, light can be transmitted also to the portion where the second pixel electrode is formed in each pixel, and high display can be achieved. A liquid crystal display device having luminance can be obtained.

Further, since the second pixel electrode is formed of a transparent conductive film and a thin film transistor is formed on a gate signal line, a liquid crystal display device having higher display luminance can be obtained.

In the liquid crystal display device of the present invention, since the first pixel electrode and the second pixel electrode are made of a transparent conductive film, a portion where the first pixel electrode and the second pixel electrode are formed in each pixel. Thus, a liquid crystal display device having high display luminance can be obtained.

Further, since the first pixel electrode and the second pixel electrode are made of a transparent conductive film and thin film transistors are formed on gate signal lines, a liquid crystal display device having higher display luminance can be obtained. Can be.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram showing one embodiment of a liquid crystal display device of the present invention.

FIG. 2 is an explanatory view showing another embodiment of the liquid crystal display device of the present invention.

FIG. 3 is an explanatory diagram showing another embodiment of the liquid crystal display device of the present invention.

FIG. 4 is an explanatory view showing another embodiment of the liquid crystal display device of the present invention.

FIG. 5 is an explanatory view showing another embodiment of the liquid crystal display device of the present invention.

FIG. 6 is an explanatory view showing another embodiment of the liquid crystal display device of the present invention.

FIG. 7 is an explanatory view showing another embodiment of the liquid crystal display device of the present invention.

FIG. 8 is an explanatory diagram showing a conventional liquid crystal display device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Gate signal line 2 Source signal line 3 Common signal line 4 TFT 5 1st pixel electrode 6 2nd pixel electrode 7 Storage capacity formation part 8 Contact hole 9 Insulating film 10 Transparent insulating substrate 11 Liquid crystal molecule 12 Storage capacity

Claims (7)

[Claims] 1. Two transparent insulating substrates facing in parallel with each other, a gate signal line formed on one of the transparent insulating substrates, an insulating film formed on the gate signal line, A source signal line orthogonal to the gate signal line via the film,
A common signal line formed in parallel with the gate signal line, a thin film transistor to which a gate signal transmitted through the gate signal line is input, a first pixel electrode connected to the thin film transistor, A second pixel electrode connected to a signal line, and liquid crystal molecules sandwiched between the two transparent insulating substrates, wherein the switching of the thin film transistor is controlled by inputting the gate signal; A source signal transmitted through the source signal line is transmitted to the first signal through the thin film transistor.
The potential of the first pixel electrode is controlled by being applied to the first pixel electrode, and the common signal transmitted through the common signal line is applied to the second pixel electrode, whereby the first pixel electrode is controlled. A liquid crystal display device in which an electric field generated between a pixel electrode and the second pixel electrode in a horizontal direction on a surface of the transparent insulating substrate is controlled to drive the liquid crystal molecules, wherein the gate signal A liquid crystal display device comprising the thin film transistor formed on a line. 2. Two transparent insulating substrates facing in parallel with each other, a gate signal line formed on one of the transparent insulating substrates, an insulating film formed on the gate signal line, and the insulating film. A source signal line orthogonal to the gate signal line via the film,
A common signal line formed in parallel with the gate signal line, a thin film transistor to which a gate signal transmitted through the gate signal line is input, a first pixel electrode connected to the thin film transistor, A second pixel electrode connected to a signal line, and liquid crystal molecules sandwiched between the two transparent insulating substrates, wherein the switching of the thin film transistor is controlled by inputting the gate signal; A source signal transmitted through the source signal line is transmitted to the first signal through the thin film transistor.
The potential of the first pixel electrode is controlled by being applied to the first pixel electrode, and the common signal transmitted through the common signal line is applied to the second pixel electrode, whereby the first pixel electrode is controlled. A liquid crystal display device in which an electric field generated between a pixel electrode and the second pixel electrode in a horizontal direction on a surface of the transparent insulating substrate is controlled to drive the liquid crystal molecules; A liquid crystal display device, wherein the pixel electrode is made of a transparent conductive film. 3. The liquid crystal display device according to claim 2, wherein said thin film transistor is formed on said gate signal line. 4. Two transparent insulating substrates opposing each other in parallel, a gate signal line formed on one of the transparent insulating substrates, an insulating film formed on the gate signal line, A source signal line orthogonal to the gate signal line via the film,
A common signal line formed in parallel with the gate signal line, a thin film transistor to which a gate signal transmitted through the gate signal line is input, a first pixel electrode connected to the thin film transistor, A second pixel electrode connected to a signal line, and liquid crystal molecules sandwiched between the two transparent insulating substrates, and the switching of the thin film transistor is controlled by inputting the gate signal; A source signal transmitted through the source signal line is transmitted to the first signal through the thin film transistor.
The first pixel electrode is controlled in potential by being applied to the first pixel electrode, and the common signal transmitted through the common signal line is applied to the second pixel electrode, whereby the first pixel electrode is controlled. A liquid crystal display device in which an electric field generated between a pixel electrode and the second pixel electrode in a horizontal direction on a surface of the transparent insulating substrate is controlled to drive the liquid crystal molecules; A liquid crystal display device, wherein the pixel electrode is made of a transparent conductive film. 5. The liquid crystal display device according to claim 4, wherein said thin film transistor is formed on said gate signal line. 6. Two transparent insulating substrates facing each other in parallel, a gate signal line formed on one of the transparent insulating substrates, an insulating film formed on the gate signal line, and the insulating film. A source signal line orthogonal to the gate signal line via the film,
A common signal line formed in parallel with the gate signal line, a thin film transistor to which a gate signal transmitted through the gate signal line is input, a first pixel electrode connected to the thin film transistor, A second pixel electrode connected to a signal line, and liquid crystal molecules sandwiched between the two transparent insulating substrates, wherein the switching of the thin film transistor is controlled by inputting the gate signal; A source signal transmitted through the source signal line is transmitted to the first signal through the thin film transistor.
The potential of the first pixel electrode is controlled by being applied to the first pixel electrode, and the common signal transmitted through the common signal line is applied to the second pixel electrode, whereby the first pixel electrode is controlled. A liquid crystal display device in which an electric field generated between a pixel electrode and the second pixel electrode in a horizontal direction on a surface of the transparent insulating substrate is controlled to drive the liquid crystal molecules, Wherein the pixel electrode and the second pixel electrode are made of a transparent conductive film. 7. The liquid crystal display device according to claim 6, wherein the thin film transistor is formed on the gate signal line.