JPH11142881A - Active matrix type liquid crystal display device, its manufacture and driving method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve a visual angle characteristic by forming two or more areas having respectively different orientation azimuths of liquid crystalline molecules in one pixel area without increasing the step of manufacturing processes. SOLUTION: Auxiliary electrodes 4 each of which divides one pixel electrode 3 into two areas are formed on a substrate 1 and driving voltage is impressed to respective pixel electrodes 3, respective auxiliary electrodes 4 and a counter electrode 6 so that the field strength of a 2nd electric field generated between the counter electrode 6 and each auxiliary electrode 4 is higher than the field strength of an electric field generated between the electrode 6 and each pixel electrode 3 and the direction of the 1st electric field is almost equal to that of the 2nd electric field. Thereby two orientation areas in which the inclinations of liquid crystalline molecules 7 are mutually reversed are formed on both the pixel electrodes 3 with the electrode 4 intervened.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an active matrix type liquid crystal display device for displaying images, and a method for manufacturing and driving the same.

[0002]

2. Description of the Related Art Among liquid crystal display devices, in order to obtain an image having particularly high display quality, active matrix driving type liquid crystal display devices using thin film transistors as switching elements have been actively developed in recent years. This is because a higher contrast ratio can be obtained irrespective of the number of scanning electrodes than a simple matrix driving method without a switching element, so that a clear image can be obtained even in a high-capacity display with high resolution.

In such an active matrix type liquid crystal display device, there is a TN (Twisted Nematic) system as a widely used liquid crystal display mode. In the TN mode, a panel having a structure in which liquid crystal molecules are twisted by 90 ° between electrode substrates sandwiching a liquid crystal layer is sandwiched between two polarizing plates. The two polarizing plates are arranged so that their polarization axes are orthogonal to each other, and one of the polarizing plates is parallel or perpendicular to the long axis direction of the liquid crystal molecules in contact with one substrate.
When a voltage is not applied, white display is performed. However, when a voltage is applied between two substrates, that is, in a direction perpendicular to the liquid crystal panel, the light transmittance is gradually reduced to black display. . Such display characteristics are obtained because, when a voltage is applied to the liquid crystal panel, the liquid crystal molecules try to align in the direction of the electric field while untwisting the twisted structure. This is because the polarization state changes and the light transmittance is modulated. However, even in the same molecular alignment state, the polarization state of the transmitted light changes depending on the incident direction of the light incident on the liquid crystal panel, so that the light transmittance differs depending on the incident direction. That is, the characteristics of the liquid crystal panel have a viewing angle dependency. This viewing angle characteristic causes an inversion of luminance when the viewpoint is inclined obliquely with respect to the main viewing angle direction (the major axis direction of the liquid crystal molecules in the intermediate layer of the liquid crystal layer), which is an important issue in the image quality of the liquid crystal panel.

In recent years, efforts to improve such viewing angle characteristics have been actively made. Among the approaches, there are a method of laminating a phase compensator while using the above-mentioned TN method for the orientation of liquid crystal, and an orientation division method of giving one picture element two or more TN orientations of the liquid crystal. . Also, as a method to improve the viewing angle characteristics by changing the orientation of the liquid crystal itself,
In-Plane-Switching (IPS) to move horizontally aligned liquid crystal molecules by lateral electric field in the direction of the substrate surface.
Vertical-align (VA) method in which liquid crystal molecules are aligned perpendicular to the substrate surface and a phase compensator is laminated,
There is a VA alignment division method in which two or more alignment directions are provided in the A method (for example, K. Ohmuro et al., SID97D).
igest, p845 (1997)). As for the viewing angle characteristics of the IPS method and the VA alignment division method, a very wide viewing angle characteristic can be obtained without a luminance inversion phenomenon and a decrease in contrast. In particular, the VA alignment division system can be operated in the same active matrix array configuration as the conventional TN system, and therefore, its design is easy and promising.

[0005]

However, the VA alignment division method has the following problems. In the orientation division method, two or more orientations in which liquid crystal molecules are oriented by applying an electric field are provided in one pixel region to make viewing angle characteristics symmetric. In general, as a method for aligning liquid crystal molecules, there is a rubbing method in which an alignment film is applied on a substrate, rubbed with a cloth such as rayon, and the liquid crystal molecules are aligned in the rubbing direction. In order to provide a region having two or more orientations using this rubbing method, first, a first rubbing treatment is performed so that the orientation film is oriented in a predetermined direction, and then a resist is applied on the orientation film. After patterning by a photolithography method so that only the portion where the first rubbing process is left remains, the second rubbing process is performed again on the exposed portion of the alignment film in a direction different from the first rubbing direction.
Finally, a method of removing all the resist is used. It is necessary to perform such processing on the upper and lower substrates. Therefore, it takes a lot of time and effort to produce a liquid crystal display device of the alignment division type, and at the same time, the yield decreases due to an increase in the number of steps, and the manufacturing cost increases. The problem had arisen.

The present invention solves the above problems in the VA alignment division system without increasing the number of manufacturing steps.
One pixel region has two regions in which the liquid crystal molecules have different orientations.
An object is to provide an active matrix liquid crystal display device which can be provided as described above, and a driving method and a manufacturing method thereof.

[0007]

According to a first aspect of the present invention, there is provided an active matrix type liquid crystal display device in which a liquid crystal layer is filled between a pair of substrates facing each other. On a substrate, signal electrodes and scanning electrodes arranged in a matrix, pixel electrodes electrically connected to the signal electrodes via thin film transistors, and one pixel electrode is divided into two or more regions. An active matrix type liquid crystal display device provided with a linear auxiliary electrode disposed thereon, and a counter electrode provided on the other substrate so as to face the one substrate, wherein the counter electrode and the pixel are provided. Than the electric field strength of the first electric field generated between the
The electric field strength of a second electric field generated between the counter electrode and the auxiliary electrode is increased, and the directions of the first electric field and the second electric field are made substantially equal.

Further, according to a second aspect of the present invention, in the active matrix type liquid crystal display device according to the first aspect, the liquid crystal molecules in the liquid crystal layer are formed by:
It is characterized in that it is oriented in a direction perpendicular to the substrate when no electric field is applied.

According to a third aspect of the present invention, there is provided an active matrix type liquid crystal display device according to the first or second aspect, wherein a switch is turned on / off by a potential change of the scanning electrode in the pixel electrode. And a second thin film transistor whose switch is turned on / off by a change in the potential of the scanning electrode, and a parasitic capacitance Cgd formed between the pixel electrode and the scanning electrode. ₁ , a storage capacitor Cst ₁ formed between the pixel electrode or a charge holding electrode electrically connected to the pixel electrode and a part of a scan electrode provided in a stage preceding the scan electrode, A pixel capacitor Cl ₁ formed between the electrode and the counter electrode;
The sum of gd ₁ , Cst ₁ and Cl ₁ is Ct _1, and a parasitic capacitance Cgd formed between the auxiliary electrode and the scan electrode.
₂ and a storage capacitor Cst ₂ formed between the auxiliary electrode or a charge holding electrode electrically connected to the auxiliary electrode and a part of a scan electrode provided at a stage preceding the scan electrode.
When the sum of the capacitance Cl ₂ formed between the auxiliary electrode and the counter electrode and Cgd ₂ , Cst ₂ and Cl ₂ is Ct ₂ , (Cst ₁ / Ct ₁ ) <(Cst ₂ / Ct ₂ ) and (Cgd ₁ / C
st ₁₎ = and satisfies the relation (Cgd ₂ / Cst _2).

According to a fourth aspect of the present invention, there is provided a driving method of the active matrix type liquid crystal display device according to the third aspect, wherein the first thin film transistor and the second thin film transistor are turned on. While superimposing the modulation signal on the signal, the magnitude of the modulation signal applied to the even-numbered scanning electrodes and the modulation signal applied to the odd-numbered scanning electrodes are changed and supplied from the signal electrodes. A voltage generated from the modulation signal is superimposed on the generated image signal, and the image signal on which the voltage is superimposed is applied to the pixel electrode and the auxiliary electrode.

According to a fifth aspect of the present invention, there is provided a driving method of the active matrix type liquid crystal display device according to the fourth aspect, wherein the auxiliary electrode is arranged adjacent to an arbitrary scanning electrode. The electrodes are arranged in parallel with the scanning electrodes between the scanning electrodes, and the image signals applied to the pixel electrodes by the signal electrodes are inverted every scanning period. The direction of the electric field formed therebetween is opposite to the electric field formed between the pixel electrode connected to the adjacent scanning electrode and the counter electrode.

According to a sixth aspect of the present invention, there is provided a method of manufacturing an active matrix type liquid crystal display device according to the first, second or third aspect of the present invention, wherein the pixel electrode is formed on one of the substrates. The method is characterized by including a step of simultaneously forming a scanning electrode and an auxiliary electrode, and then sequentially forming a thin film transistor and a signal electrode.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS As described above, the active matrix type liquid crystal display device of the present invention has an auxiliary electrode formed substantially at the center of a pixel electrode so as to be parallel to a scanning electrode. The electric field strength between the pixel electrode and the counter electrode is higher than the electric field strength between the pixel electrode and the counter electrode, and the directions of the electric fields are substantially equal. The directions of electric fields between pixel electrodes adjacent to each other with one scanning electrode therebetween are opposite.

FIG. 1 shows the equipotential lines of the liquid crystal display device and the directions of the liquid crystal molecules which change according to the electric field, from the electric field distribution according to the above configuration. The liquid crystal molecules 7 filled between the substrates 1 and 2 have negative dielectric anisotropy used in the VA method. This liquid crystal molecule 7
When an electric field of a threshold voltage or more is applied, the molecular long axis is directed along the equipotential line according to the intensity. In FIG. 1, 4 V is applied to the pixel electrode 3, -4 V is applied to the pixel electrode 3 adjacent to the scanning electrode 5, 6 V is applied to the auxiliary electrode 4, -6 V is applied to the adjacent auxiliary electrode 4, and 0 V is applied to the counter electrode 6. Is applied. FIG. 1 shows 2 V,
Equipotential lines 8, 9 of -2V are drawn. Equipotential lines 8,
Numeral 9 is rapidly bent between the adjacent pixel electrodes 3 at the adjacent pixel electrodes 3, and distorted near the auxiliary electrode 4 so as to approach the counter electrode 6.

The liquid crystal molecules 7 where the equipotential lines 8 and 9 are distorted have their major axes tilted along the curved equipotential lines 8 and 9 respectively. Therefore, on the pixel electrode 3 on the left side of the auxiliary electrode 4 in FIG. 1, both the liquid crystal molecules 7 near the auxiliary electrode 4 and the liquid crystal molecules 7 on the left end of the pixel electrode 3 rotate clockwise from a direction perpendicular to the pixel electrode 3. Lean like so. Then, the liquid crystal molecules 7 on the pixel electrode 3 sandwiched between the liquid crystal molecules 7 at both ends are inclined in the same direction as the liquid crystal molecules 7 at these both ends. Similarly, the liquid crystal molecules 7 on the right side of the auxiliary electrode 4 tilt so as to rotate counterclockwise from the vertical direction. According to the above principle, two alignment regions where the inclination of the liquid crystal molecules 7 are opposite to each other are formed on the pixel electrodes 3 on both sides of the auxiliary electrode 4.

On the other hand, if a DC voltage of the same polarity is applied to the liquid crystal layer for a long time, a so-called burn-in phenomenon occurs in which a display image suffers from a decrease in luminance and an afterimage, so that it is necessary to perform AC driving. In an active matrix type liquid crystal display device, usually, after the potential written to the pixel electrode 3 during one scanning period is held for about 16 msec, which is one field period, the potential between the pixel electrode 3 and the counter electrode 6 is maintained in the next one field period. The potential is written so that the direction of the electric field between them is reversed. In other words, the voltage between the pixel electrode 3 and the counter electrode 6 is driven by an alternating current of about 30 Hz. In the active matrix type liquid crystal display device of the present invention, the direction of the electric field between the auxiliary electrode 4 and the counter electrode 6 must always be the same as the direction of the electric field between the pixel electrode 3 and the counter electrode 6. As for the voltage between the counter electrodes 6, it is necessary to perform an AC drive of about 30 Hz having the same phase as the voltage between the pixel electrodes 3 to 6.

Next, an active matrix type liquid crystal display device according to an embodiment of the present invention will be described in detail with reference to the drawings. FIG. 2 is a configuration diagram showing a main part of an active matrix type liquid crystal display device according to an embodiment of the present invention.
FIG. 3 is an equivalent circuit diagram of a main part in the embodiment shown in FIG. FIG. 4 is a characteristic diagram showing the waveform of the drive voltage for the active matrix type liquid crystal display device of the present embodiment. The voltage waveforms Vg (m-1) and Vg (m) for the scan electrode 5 are shown in FIG.
The voltage waveform Vs (n) of the signal electrode 10, the voltage waveform Vc of the counter electrode 6, the voltage waveform Vp (n) applied to the pixel electrode 3, and the voltage waveform Vps (n) applied to the auxiliary electrode 4 It is shown.

The pixel electrode 3 has a thin film transistor 11 (hereinafter, referred to as a switch) which is turned on / off by a potential of the scanning electrode 5.
The auxiliary electrode 4 is connected to a TFT 14 whose switch is turned on / off by the same potential of the scanning electrode 5. Here, the parasitic capacitance Cgd 112 formed between the pixel electrode 3 and the scanning electrode 5 and any _one of the pixel electrode 3 and the charge holding electrode (not shown) connected to the pixel electrode 3 and the scanning electrode 5 Scanning electrode 17
Of the storage capacitor Cst ₁ 13 formed between the part, the pixel electrode 3 and Ct the sum of the pixel capacitor Cl ₁ formed between the counter electrode 6 _{1 (i.e., Ct 1 = Cl 1 + Cst} 1 + Cgd with a _1), the auxiliary electrode 4 and the parasitic capacitance Cgd ₂ 15 formed between the scan electrodes 5, the portion of the charge holding electrode is electrically connected to the auxiliary electrode 4 or the auxiliary electrode 4 previous scan electrodes 17 and the storage capacitor Cst ₂ 16 formed between the auxiliary electrodes 4 and Ct the sum of the capacitance Cl ₂ formed between the counter electrode 6 ₂ (i.e., Ct ₂
= Cl ₂ + Cst ₂ + Cgd ₂ ), (Cst ₁ / Ct ₁ ) in the active matrix type liquid crystal display device of the present embodiment.
<In (Cst ₂ / Ct _2), and _{(Cgd 1 / Cst 1) =} (Cgd 2 / Cs
t ₂ ), each capacitance Cl ₂ , Cst ₂ , Cg
d ₂ , Cl ₂ , Cst ₂ and Cgd ₂ are set. And
For the active matrix type liquid crystal display device of the present embodiment configured as described above, a driving method called capacitive coupling driving is adopted (for example, E. Takeda et al., P.
roc. Japan Display '89, p580 (1989)).

In the capacitive coupling drive, a modulation signal is applied in addition to the scanning signal for turning on the TFTs 11 and 14 and the magnitude of the modulation signal is changed by the even-numbered and odd-numbered scanning electrodes 5 and 17. This is a driving method in which a voltage in which a voltage generated from a modulation signal is superimposed on the pixel electrode 3 and the auxiliary electrode 4 in addition to the signal voltage supplied from the signal electrode 10.

Next, the capacitive coupling drive for the active matrix type liquid crystal display device of this embodiment will be described with reference to FIG. 4. The scanning voltage waveforms Vg (m-1) and Vg (m) are as follows.
It has four voltage levels of modulation signals Vg (+) and Vg (-) in addition to Vgon for turning on and off Vgoff of the TFTs 11 and 14. As shown, the modulation signal Vg (+)
And Vg (-) are applied for two scanning periods after the voltage of Vgon is applied for one scanning period, and then the voltage of Vgoff is applied. In the same field, if the modulation signal of Vg (m-1) is Vg (+), the modulation signal of Vg (m) is Vg (-).
The modulation signals Vg (+) and Vg (-) are applied alternately for each field in both Vg (m-1) and Vg (m). Further, the signal voltage waveform Vs (n) is such that a voltage of Vs (+) having a positive polarity and a voltage of Vs (-) having a negative polarity are applied to the counter electrode voltage Vc every scanning period, and one field. Vgo every time
The polarity of plus and minus when n becomes reversed.

Here, the voltage Vp applied to the pixel electrode 3
(n) and the voltage Vps (n) applied to the auxiliary electrode 4 are as follows: when Vg (m) is Vgon, after Vs (+) is written in a certain field, the voltage of the previous stage Vg (m-1) In accordance with the fluctuation and the voltage fluctuation of Vg (m), the potential fluctuates so that the sum of the electric charges of the respective capacitors at the time of writing is preserved. That is, Vg (m-1), Vg (m)
Become Vgoff, and Vp (n) and Vps (n) settle down to a constant voltage only after the voltage fluctuation disappears. At this time, the potentials of Vp (n) and Vps (n) are as follows.

[0022]

(Equation 1)

[0023]

(Equation 2)

Accordingly, in equations (1) and (2), the voltage of the second term on the right side is superimposed on Vs (+), and in the active matrix type liquid crystal display of this embodiment, Since (Cst ₁ / Ct ₁ ) <(Cst ₂ / Ct ₂ ), the potential of Vps (n) is higher than Vp (n), and the potential difference between the pixel electrode 3 and the counter electrode 6 is reduced. On the other hand, the potential difference between the auxiliary electrode 4 and the counter electrode 6 can be increased. Also, in the next field,

[0025]

(Equation 3)

[0026]

(Equation 4)

Thus, the potential difference between the auxiliary electrode 4 and the counter electrode 6 can be made larger than the potential difference between the pixel electrode 3 and the counter electrode 6. From the above, the equipotential lines as shown in FIG. 1 can be always realized.

[0028] In _{addition, (Vgd 1 / Vct 1)} = (Vgd 2 / Vct 2)
By doing so, it is possible to perform AC drive in which both the potential of the pixel electrode 3 and the potential of the auxiliary electrode 4 are symmetrical with respect to the potential of the counter electrode 6, thereby preventing a DC component from being superimposed on the drive voltage. Thus, the liquid crystal layer can be kept stable.

Next, a method of manufacturing the active matrix type liquid crystal display device of the present embodiment will be described. When manufacturing the active matrix type liquid crystal display device of the present embodiment, first, an ITO (Indium Tin Oxide) is formed on the substrate 1 and the ITO is formed on the substrate 1 by photolithography.
The pixel electrode 3 is formed in a predetermined shape above. Next, after a SiO ₂ film (not shown) is formed on the upper surface of the substrate 1, the scanning electrode 5 and the auxiliary electrode 4 are separated from each other by a predetermined distance as shown in FIG. Form a pattern. The material of the scanning electrode 5 and the auxiliary electrode 4 is not limited to chromium, but may be a conductive single-layer film or a multilayer film such as aluminum or an alloy containing aluminum as a main component.

After the scanning electrode 5 and the auxiliary electrode 4 are formed on the substrate 1, on the scanning electrode 5, for example, silicon nitride (SiN) is used as an insulating film of the TFT 11 connected to the pixel electrode 3 and the TFT 14 connected to the auxiliary electrode. An insulator layer (not shown) such as SiNx) is laminated. Further, on this insulator layer, TFT1
Semiconductor layers made of, for example, amorphous silicon (α-Si), which perform the switching functions of 1 and 14, are stacked.

Thereafter, two layers of titanium / aluminum (Ti / Al) are laminated on the semiconductor layer so that the signal electrodes 10 are substantially orthogonal to the scanning electrodes 5 on the substrate 1 and are substantially parallel to each other. To form a pattern. Further, drain electrodes of the TFT 11 and the TFT 14 are formed so as to partially overlap the semiconductor layer. These drain electrodes are respectively connected to the pixel electrode 3 and the auxiliary electrode 4 via contact holes. At this time, the parasitic capacitances Cgd ₁ 12 and Cgd ₂ 15
Are simultaneously formed between the scanning electrode 5 and the drain electrode in a shape having a predetermined capacitance value. Further, the storage capacitor Cst ₁ 13 and the storage capacitance Cst ₂ 16 is on the front of the scanning electrodes 17, by stacking so as to have a predetermined area, is formed so as to have a predetermined capacitance value. These storage capacities Cst
₁ 13 and Cst ₂ 16 is connected to the pixel electrode 3 and the auxiliary electrode 4, respectively, via the contact hole. The material is not limited to titanium / aluminum (Ti / Al), and a single-layer film or a multilayer film of a conductive metal may be used.

Finally, the insulator layer (two layers of SiNx and SiO ₂ ) on the pixel electrode 3 and the auxiliary electrode 4 is etched with hydrogen fluoride to expose the pixel electrode 3 and the auxiliary electrode 4, thereby making the active layer active. A matrix array substrate is created.

Then, an alignment film (ODS-E manufactured by Chisso Corporation) for vertically aligning liquid crystal molecules is applied to the electrode-side surface of the active matrix array substrate and the substrate 2 on which the counter electrode 6 is formed, respectively. After bonding these two substrates, a liquid crystal layer containing liquid crystal molecules having negative dielectric anisotropy was filled between the substrates, and an active matrix liquid crystal display device was obtained.

In the active matrix type liquid crystal display device of this embodiment, each capacitance value is Cgd ₁ = 0.1 p
F, Cst ₁ = 0.5 pF, Cl ₁ = 0.4 pF, Cgd ₂ = 0.06 pF, C
It was designed so that st ₂ = 0.3 pF and Cl ₂ = 0.04 pF. _{Therefore, (Cgd 1 / Cst 1)} = (Cgd 2 / Cst 2) = 0.2 , and the same time _{(Cst 1 / Ct 1) =} 0.5, (Cst 2 / Ct 2) = 0.75
And (Cst ₁ / Ct ₁ ) <(Cst ₂ / Ct ₂ ) was satisfied.

The scanning electrodes 5 and 17 have Vgon = 15
V, Vgoff = -15V, Vg (+) =-10V, Vg (-) =-26V
Is applied to the signal electrode 10 with Vs (+) = 2V and Vs (-) =
By applying an image signal of −2 V and Vc = 0 V to the counter electrode 6, the potential of the pixel electrode 3 becomes Vp (n) =
± 6 V and the potential Vps (n) of the auxiliary electrode 4 are calculated as ± 8 V. For a potential difference of 6 V between the pixel electrode 3 and the counter electrode 6,
The potential difference between the auxiliary electrode 4 and the counter electrode 6 could be designed to be as high as 8V.

When the liquid crystal display was driven under such driving conditions and the alignment of the liquid crystal molecules 7 on the pixel electrode 3 was observed, two alignment regions appeared with the auxiliary electrode 4 as a boundary. Furthermore, when observing with a polarizing microscope under crossed Nicols while tilting the liquid crystal display device, the tilt angle at which the extinction position can be obtained is symmetrical with respect to the normal direction of the substrate in the two alignment regions. It was confirmed that the liquid crystal molecules 7 in the two alignment regions were inclined in a direction symmetric to the normal direction of the substrate as schematically shown in FIG.

[0037]

As described above, according to the active matrix type liquid crystal display device of the present invention, two or more regions having different orientations of the liquid crystal molecules are provided in one pixel region, thereby having a wide viewing angle characteristic. A liquid crystal display device can be provided.

Further, according to the driving method of the active matrix type liquid crystal display device of the present invention, since the orientation of each liquid crystal molecule in two or more regions provided in one pixel region can be made different, an image can be displayed. Wide viewing angle characteristics during display can be improved.

According to the method of manufacturing an active matrix type liquid crystal display device of the present invention, two or more regions having different alignments of liquid crystal molecules can be provided in one pixel region without increasing the number of manufacturing steps.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a configuration of an active matrix type liquid crystal display device according to an embodiment of the present invention.

FIG. 2 is a configuration diagram illustrating a main part of an active matrix liquid crystal display device according to an embodiment of the present invention.

FIG. 3 is an equivalent circuit diagram of a main part in the embodiment shown in FIG. 2;

FIG. 4 is a characteristic diagram showing a drive voltage waveform for the active matrix type liquid crystal display device according to the embodiment of the present invention.

[Explanation of symbols]

1, 2 Substrate 3 Pixel electrode 4 Auxiliary electrode 5, 17 Scan electrode 6 Counter electrode 7 Liquid crystal molecule 8, 9 Equipotential line 10 Signal electrode 11, 14 TFT 12 Parasitic capacitance Cgd ₁ 13 Storage capacitance Cst ₁ 15 Parasitic capacitance Cgd ₂ 16 Storage capacity Cst ₂

Claims (6)

[Claims] 1. A liquid crystal layer is filled between a pair of substrates opposed to each other. On one substrate, signal electrodes and scanning electrodes arranged in a matrix are electrically connected to the signal electrodes via thin film transistors. And a linear auxiliary electrode disposed so as to divide one pixel electrode into two or more regions. On the other substrate, the pixel electrode is opposed to the one substrate. An active matrix liquid crystal display device provided with a counter electrode, wherein the voltage is generated between the counter electrode and the auxiliary electrode than the electric field strength of a first electric field generated between the counter electrode and the pixel electrode. Increasing the electric field strength of the second electric field,
An active matrix liquid crystal display device, wherein the direction of the electric field is substantially equal to the direction of the second electric field. 2. The active matrix liquid crystal display device according to claim 1, wherein the liquid crystal molecules in the liquid crystal layer are oriented in a direction perpendicular to the substrate when no electric field is applied. 3. A first thin film transistor whose switch is turned on / off by a potential change of a scanning electrode is connected to a pixel electrode, and a second thin film transistor whose switch is turned on / off by a potential change of the scanning electrode is connected to an auxiliary electrode. connect the thin film transistor, a parasitic capacitance Cgd ₁ formed between the scan electrode and the pixel electrode is provided on the previous stage to the pixel electrode or the pixel electrode and the scanning electrode and the charge holding electrode electrically connected to part of the resulting scan electrodes and the storage capacitor Cst ₁ formed between the pixel electrode and Ct the sum of the pixel capacitor Cl ₁ formed between the counter electrode _{1 (Ct 1 = Cl 1 +} Cst ₁ + Cgd ₁ )
With a, and the parasitic capacitance Cgd ₂ formed between the scan electrode and the auxiliary electrode, disposed in the preceding stage with respect to the auxiliary electrode or the and the charge holding electrode electrically connected to the auxiliary electrode and the scan electrode Ct ₂ (Ct ₂ = Cl ₂ + Cst ₂₎ which is the sum of the storage capacitance Cst ₂ formed between the scanning electrode and a part of the scanning electrode and the capacitance Cl ₂ formed between the auxiliary electrode and the counter electrode. + Cgd ₂ )
When _{a, (Cst 1 / Ct 1)} < In (Cst ₂ / Ct _2), and (Cgd ₁ / Cst ₁₎
= Active matrix liquid crystal display device according to claim 1 or 2, wherein the satisfying (Cgd ₂ / Cst ₂₎ relationship. 4. A driving method for driving an active matrix type liquid crystal display device according to claim 3, wherein a modulation signal is superimposed on a scanning signal for turning on the first thin film transistor and the second thin film transistor, and the modulation signal is superposed on an even number. By changing the magnitude of the modulation signal applied to the arranged scanning electrodes and the modulation signal applied to the odd-numbered scanning electrodes, a voltage generated from the modulation signal is applied to an image signal supplied from the signal electrode. A method for driving an active matrix liquid crystal display device, comprising superimposing and applying an image signal on which this voltage is superimposed to a pixel electrode and an auxiliary electrode. 5. An auxiliary electrode is arranged between an arbitrary scanning electrode and an adjacent scanning electrode in parallel with the scanning electrode, and an image signal applied to the pixel electrode by the signal electrode is inverted every scanning period. And the direction of the electric field formed between the pixel electrode connected to an arbitrary scan electrode and the counter electrode with respect to the electric field formed between the pixel electrode connected to the adjacent scan electrode and the counter electrode. 5. The driving method of an active matrix type liquid crystal display device according to claim 4, wherein the driving method is reversed. 6. The method according to claim 1, further comprising a step of simultaneously forming a scanning electrode and an auxiliary electrode on one of the substrates on which the pixel electrodes are formed, and thereafter sequentially forming a thin film transistor and a signal electrode. 4. The method for manufacturing an active matrix type liquid crystal display device according to item 3.