JP2001083479A - Liquid crystal display device, its production and method for driving liquid crystal display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a liquid crystal display device in which transition to bend alignment is almost surely caused and the transition is completed in a short time without producing display defects, which has fast response and a wide viewing field and which is suitable for the display of animation images by applying an AC voltage with a bias voltage superposed between substrates to transit the liquid crystal layer into the bend alignment. SOLUTION: When the power is supplied, the switch controlling circuit 33 sends switching signals S1, S2 to switching circuits 32a, 32b, respectively, to connect a common contact point Q1 to an individual contact point P1 and to connect a common contact point Q2 to an individual contact point P3. Thus, a driving voltage is applied from a driving circuit 30 for transition of alignment on between electrodes 22, 23. The driving voltage is an AC voltage of an AC square wave voltage with a bis voltage superposed, and the driving voltage is controlled to be higher than the critical voltage which is the minimum voltage necessary to cause the transition from splay alignment to bend alignment. By applying the aforementioned driving voltage, the transition time can be significantly reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a high-speed and wide-view OCB mode liquid crystal display device for displaying television images, personal computers, and multimedia images, a method of manufacturing the same, and a method of driving the liquid crystal display device.

[0002]

2. Description of the Related Art Conventionally, as a liquid crystal display device, for example, as a liquid crystal display mode, a twisted nematic (TN) mode using a nematic liquid crystal having a positive dielectric anisotropy.
LCD devices have been put to practical use, but the response is slow,
There are drawbacks such as a narrow viewing angle. There are also display modes such as a ferroelectric liquid crystal (FLC) and an antiferroelectric liquid crystal, which have a quick response and a wide viewing angle, but have major drawbacks in image sticking, shock resistance, temperature dependence of characteristics, and the like. . In addition, there is an in-plane switching (IPS) mode in which a viewing angle is extremely wide and liquid crystal molecules are driven in a horizontal electric field in a plane, but the response is slow, the aperture ratio is low, and the luminance is low. In order to display full-color video on a large screen, a liquid crystal mode with a wide field of view, high brightness, and high-speed display performance is required, but there is currently a practical liquid crystal display mode that satisfies this perfectly. do not do.

Conventionally, as a liquid crystal display device aiming at high luminance at least in a wide field of view, there is a liquid crystal display device in which the above-mentioned TN mode liquid crystal region is divided into two orientations to increase the viewing angle vertically (S).
ID92 DIGEST P798-801). That is,
A nematic liquid crystal having a positive dielectric anisotropy is used in each display pixel of the liquid crystal display device to form two liquid crystal regions in a TN mode and different orientations of liquid crystal molecules. It is to expand.

FIG. 48 shows a conceptual diagram of the structure of the conventional liquid crystal display device. In FIG. 48, 701 and 702 are glass substrates, 703 and 704 are electrodes, and 705 and 7
05 ', 706, 706' are alignment films. Nematic liquid crystal molecules 707, 70 having a positive dielectric anisotropy slightly inclined from the upper and lower substrate interfaces facing each other in one alignment region A.
A large or small pretilt angle of 7 'is formed, and the magnitude of the pretilt angle in the other orientation region B is set opposite to the orientation region A with respect to the upper and lower substrate interfaces facing each other. The large and small pretilt angles are set so as to make a difference of several degrees. As an example of a conventional manufacturing method of forming alignment regions having different pretilt angles on the upper and lower substrates, a photoresist is applied to an alignment film, masking is performed by photolithographic technology, and a desired alignment film surface is rubbed in a predetermined direction. There is a method such as repeating the work to do. With the above configuration, FIG.
As shown in FIG. 8, the orientations of the liquid crystal molecules at the center of the liquid crystal layer in the alignment regions A and B are opposite to each other, and the liquid crystal molecules in each alignment region rise in reverse with the application of a voltage. On the other hand, the refractive index anisotropy is averaged, and the viewing angle can be expanded. In the above-described conventional orientation two-split TN mode, the viewing angle is expanded compared to the normal TN mode, and the vertical viewing angle is about ± 35 degrees with a contrast of 10.

[0005] However, the response speed is about 50 mS substantially unchanged from the TN mode. As described above, the viewing angle and the response are insufficient in the above-mentioned conventional two-segment TN mode.

A liquid crystal display mode utilizing a so-called homeotropic alignment mode in which liquid crystal molecules are aligned almost vertically at an interface of an alignment film. Although there is a device, the response speed between binary values of black and white still takes about 25 ms, especially the response speed between gray shades is 50 to 80 ms, which is longer than about 1/30 s, which is called the visual recognition speed of the human eye. The image appears to flow.

On the other hand, a bend alignment type liquid crystal display device (OCB mode liquid crystal display device) utilizing a change in the refractive index due to a change in the rising angle of each liquid crystal molecule in a state where the liquid crystal molecules between the substrates are in a bend alignment is known. Proposed. The alignment change speed of the bend-aligned liquid crystal molecules between the on state and the off state is much faster than the alignment change speed between the on and off states of the TN type liquid crystal display device.
A liquid crystal display device having a high response speed can be provided. Further, in the bend alignment type liquid crystal display device, since liquid crystal molecules are entirely in bend alignment between the upper and lower substrates, self-compensation can be performed in terms of optical phase difference. It has the potential to be a liquid crystal display device with a wide field of view.

[0008]

By the way, the above-mentioned liquid crystal display device is usually produced by applying liquid crystal molecules to a splay alignment state between substrates under no voltage. In order to change the refractive index using the bend alignment, it is necessary to uniformly transition the entire display section from the splay alignment state to the bend alignment state before starting use of the liquid crystal display device. When a voltage is applied between the opposing display electrodes, the transition nucleus from the splay alignment to the bend alignment is not uniformly generated at the periphery of the dispersed spacers, or at the alignment unevenness at the interface of the alignment film or a flaw. . In addition, since the transition nucleus does not always occur from the above-mentioned fixed location, a display defect is liable to occur when the transition occurs or does not occur. Therefore, it is very important to make the transition from the splay alignment to the bend alignment at least in the entire display unit evenly before the start of use.

However, conventionally, even if a simple AC voltage is applied, no transition occurs, and even if it occurs, the transition time is extremely long.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a bend alignment having a bend alignment that almost certainly occurs, and has no display defects due to completion of the transfer in a very short time, has a high response speed, is suitable for displaying moving images, and has a wide field of view. The present invention proposes a liquid crystal display device of the type, a manufacturing method thereof, and a driving method of the liquid crystal display device.

[0011]

According to a first aspect of the present invention, there is provided a liquid crystal display device comprising: a pair of substrates; and a liquid crystal layer sandwiched between the substrates. The liquid crystal layer has a splay alignment in which the pretilt angles of the liquid crystal at the upper and lower interfaces are opposite to each other, and the liquid crystal layer is aligned in parallel with each other. Prior to driving the liquid crystal display, the liquid crystal layer is oriented by applying a voltage between the substrates. Performing an initialization process to transfer from the splay alignment to the bend alignment, and a driving method for performing an alignment transition from the splay alignment to the bend alignment in a liquid crystal display device that performs liquid crystal display driving in the initialized bend alignment state. An AC voltage on which a voltage is superimposed is applied between the substrates to transfer the liquid crystal layer to bend alignment.

According to the above method, the transition time is shortened by applying an AC voltage on which a bias voltage is superimposed between the substrates, as compared with a case where an AC voltage is simply applied.
This is because, due to the superposition of the bias voltage, the orientation of the liquid crystal molecules in the liquid crystal layer is fluctuated by the bias voltage, and the liquid crystal molecules are shifted to one substrate side. As a result, a transition nucleus is reliably generated within a short time in the liquid crystal layer, and the transition time is shortened. In addition, the transition time is further shortened by increasing the effective voltage.

The invention according to claim 2 includes a pair of substrates, and a liquid crystal layer sandwiched between the substrates, wherein when no voltage is applied, the liquid crystal layer has a liquid crystal layer whose upper and lower interfaces have opposite pretilt angles of positive and negative.
Prior to driving the liquid crystal display, the liquid crystal layer is subjected to an initialization process of changing the alignment state of the liquid crystal layer from the splay alignment to the bend alignment by a voltage application between the substrates, In the driving method for causing the liquid crystal display device to perform liquid crystal display driving in the initialized bend alignment state for performing the alignment transition from the splay alignment to the bend alignment, applying an AC voltage on which the bias voltage is superimposed between the substrates. And the step of electrically opening the substrates is alternately repeated to transfer the liquid crystal layer to bend alignment.

By providing an electrical open state period after the application of an AC voltage as in the above configuration, the liquid crystal molecules in the liquid crystal layer are shaken, and the liquid crystal molecules are shifted to one substrate side. As a result, a transition nucleus is reliably generated within a short time in the liquid crystal layer, and the transition time is shortened.

According to a third aspect of the present invention, the liquid crystal device includes a pair of substrates and a liquid crystal layer sandwiched between the substrates.
Prior to driving the liquid crystal display, the liquid crystal layer is subjected to an initialization process of changing the alignment state of the liquid crystal layer from the splay alignment to the bend alignment by a voltage application between the substrates, In the driving method for causing the liquid crystal display device to perform liquid crystal display driving in the initialized bend alignment state, in which the liquid crystal display device performs the alignment transition from the splay alignment to the bend alignment, a step of applying an AC voltage superimposed with a bias voltage between the substrates. And alternately repeating the step of applying a zero voltage or a low voltage between the substrates to transfer the liquid crystal layer to bend alignment.

By providing a zero voltage or low voltage application period after the application of the AC voltage as in the above configuration, the degree of fluctuation of the liquid crystal molecule alignment of the liquid crystal layer becomes larger than that of the second aspect of the present invention. Therefore, the phenomenon that the liquid crystal molecules are shifted to one substrate side occurs in a very short time. This will further speed up the transition time.

According to a fourth aspect of the present invention, in the method for driving a liquid crystal display device according to the second or third aspect, a DC voltage is used instead of the AC voltage on which the bias voltage is superimposed.

As described above, even if a DC voltage is applied instead of an AC voltage, after the DC voltage is applied,
Since there is a zero voltage or low voltage application period, the liquid crystal molecule orientation of the liquid crystal layer fluctuates. Therefore, also in such a driving method, the transition time can be shortened.

According to a fifth aspect of the present invention, in the driving method of the liquid crystal display device according to the second aspect, the frequency of the alternating voltage is in a range of 0.1 Hz to 100 Hz,
The duty ratio of the alternating voltage is in the range of 1: 1 to 1000: 1.

Here, the "alternately repeated voltage" means a voltage when the alternating repetition of the AC voltage application period and the electrically open state period is considered as one voltage waveform as a whole. The frequency and duty ratio of such alternately repeated voltages are regulated for the following reasons.

When the frequency is less than 0.1 Hz, the alternating repetition hardly occurs, so that the occurrence of the offset of the liquid crystal molecule alignment due to the alternating repetition does not occur. On the other hand, if the frequency is higher than 100 Hz, the frequency of the alternating repetition is too high and approaches the DC voltage, so that the occurrence of the bias of the liquid crystal molecule alignment due to the alternating repetition does not occur.

When the duty ratio is smaller than 1: 1 (for example, 1: 5), a sufficient voltage cannot be applied to the liquid crystal layer. On the other hand, when the duty ratio is larger than 1000: 1, the DC voltage approaches a DC voltage with almost no repetition of the alternation,
The occurrence of offset of the liquid crystal molecule alignment due to the alternating repetition does not occur.

According to a sixth aspect of the present invention, in the driving method of the liquid crystal display device according to the third aspect, the frequency of the alternately repeated voltage is in a range of 0.1 Hz to 100 Hz,
The duty ratio of the alternating voltage is at least in the range of 1: 1 to 1000: 1.

The frequency and duty ratio of the voltage that is alternately repeated are regulated for the same reason as in the sixth aspect.

According to a seventh aspect of the present invention, in the method for driving a liquid crystal display device according to the first aspect, the method is a method for driving an active matrix type liquid crystal display device, wherein the AC voltage is formed on one of the substrates. The voltage is applied between a pixel electrode of an active matrix type liquid crystal display device connected to a switching element and a common electrode formed on the other substrate.

According to the above configuration, the transition time can be reduced in the active matrix type liquid crystal display device.

[0027] The invention described in claim 8 is the invention according to claims 2, 3,
7. The method of driving a liquid crystal display device according to any one of claims 5 and 6, wherein the AC voltage is connected to a switching element formed on one of the substrates. Is applied between the pixel electrode of the liquid crystal display device of the type and the common electrode formed on the other substrate.

According to the above configuration, the transition time can be reduced in the active matrix type liquid crystal display device.

According to a ninth aspect of the present invention, in the driving method of the liquid crystal display device according to the eighth aspect, the AC voltage is applied to a common electrode.

According to the above configuration, the transition time can be shortened.

According to a tenth aspect of the present invention, in the driving method of the liquid crystal display device according to the fourth aspect, the direct current voltage is formed on one of the substrates. The voltage is applied between a pixel electrode of an active matrix type liquid crystal display device connected to a switching element and a common electrode formed on the other substrate.

According to the above configuration, the transition time can be shortened in an active matrix type liquid crystal display device.

According to an eleventh aspect of the present invention, in the driving method of the liquid crystal display device according to the tenth aspect, the DC voltage is
It is characterized in that it is applied to a common electrode.

According to the above configuration, the transition time can be shortened.

According to a twelfth aspect of the present invention,
In the method for driving a liquid crystal display device according to any one of 3, 5, 6, 7, 8, and 9, the voltage value of the AC voltage is necessary for causing the liquid crystal layer to transition from a splay alignment state to a bend alignment state. It is characterized by being set to a critical voltage value which is a minimum voltage value.

With the above configuration, it is possible to reduce the voltage.

According to the thirteenth aspect of the present invention,
In the method for driving a liquid crystal display device according to any one of 0 and 11, the voltage value of the DC voltage is a critical voltage value that is a minimum voltage value required to cause a liquid crystal layer to transition from a splay alignment state to a bend alignment state. Is set to.

With the above configuration, the voltage can be reduced.

According to the fourteenth aspect of the present invention,
3. The method for driving a liquid crystal display device according to any one of 3.
The voltage is a voltage which is converted into an average over time.

With the above configuration, the deterioration of the liquid crystal can be prevented.

According to a fifteenth aspect of the present invention, a pair of substrates are provided.
A liquid crystal layer sandwiched between substrates, and when no voltage is applied, the liquid crystal layer has a splay alignment in which the pretilt angles of the liquid crystal at the upper and lower interfaces are opposite in the positive and negative directions and are aligned in parallel with each other. Prior to this, a voltage is applied between the substrates to perform an initialization process of changing the alignment state of the liquid crystal layer from the splay alignment to the bend alignment, and the liquid crystal display device performs liquid crystal display driving in the initialized bend alignment state. And a voltage application unit for applying an AC voltage or a DC voltage with a bias voltage superimposed between the substrates in order to change the liquid crystal layer from the splay alignment to the bend alignment.

With the above configuration, a liquid crystal display device having a short transition time is realized.

According to a sixteenth aspect of the present invention, in the liquid crystal display device according to the fifteenth aspect, the voltage value of the AC voltage or the DC voltage is a minimum value necessary for transitioning the liquid crystal layer from the splay alignment state to the bend alignment state. It is characterized by being set to a critical voltage value which is a voltage value.

With the above configuration, a liquid crystal display device having a short transition time is realized.

According to a seventeenth aspect of the present invention, the pretilt angles of the liquid crystal at the upper and lower interfaces of the liquid crystal layer disposed between the array substrate having the pixel electrodes and the opposing substrate having the common electrode are opposite in polarity.
In a splay alignment liquid crystal cell that is aligned in parallel with each other, it is in a splay alignment when no voltage is applied, and prior to driving the liquid crystal display, an initialization process of transitioning from the splay alignment to the bend alignment by applying a voltage is performed, In an active matrix type liquid crystal display device that performs liquid crystal display driving in the initialized bend alignment state, a pretilt angle of liquid crystal in an alignment film formed on the inner surface side of the array substrate indicates a first pretilt angle, A first liquid crystal cell region in which the pretilt angle of the liquid crystal in the alignment film formed on the inner surface side of the opposing substrate has a second pretilt angle larger than the first pretilt angle; and a first liquid crystal cell region. When the pretilt angle of the liquid crystal in the alignment film disposed adjacently and formed on the inner surface side of the array substrate indicates a third pretilt angle, And a second liquid crystal cell region having a fourth pretilt angle in which the liquid crystal pretilt angle in the alignment film formed on the inner surface side of the opposing substrate is smaller than the third pretilt angle. A disclination between the pixel electrode and the common electrode, and a liquid crystal cell in which the alignment film has been subjected to alignment processing from a first liquid crystal cell region to a second liquid crystal cell region. Applying a first voltage for forming a line;
A first voltage applying means for forming a disclination line near the boundary between the liquid crystal cell region and the second liquid crystal cell region, and a voltage lower than the first voltage between the pixel electrode and the common electrode. And a second voltage applying means for generating a transition nucleus in the disclination line by applying a high second voltage and causing a transition from the splay orientation to the bend orientation.

With the above configuration, a first voltage is applied between the pixel electrode and the common electrode, so that a first voltage is applied between the first liquid crystal cell region and the second liquid crystal cell region. A disclination line having a high strain energy can be formed, and further by applying a second voltage higher than a first voltage between the pixel electrode and the common electrode, Energy is applied to the ligation line, and the splay alignment changes to the bend alignment in the disclination line.

Therefore, in the liquid crystal display device having the above-described structure, the splay-bend alignment transition can be surely caused at a fixed place (disclination line) in each pixel region where a large number of liquid crystal cells are formed. In addition, it is possible to surely cause the alignment transition to occur quickly, and to realize a liquid crystal display device having high image quality and excellent in price without causing display defects.

The invention according to claim 18 is the liquid crystal display device according to claim 17, wherein the first and fourth pretilt angles are 3 degrees or less, and the second and third pretilt angles are 4 degrees or less. It is characterized in that it is higher than degree.

With the above configuration, the ratio between the second and fourth pretilt angles and the first and fourth pretilt angles can be increased. Can be formed, and the transition time from splay alignment to bend alignment can be further reduced.

According to a nineteenth aspect of the present invention, in the liquid crystal display device according to the seventeenth aspect, the orientation of the alignment film is perpendicular to a signal electrode line or a gate electrode line along the pixel electrode. It is characterized by being.

With the above configuration, a horizontal electric field is applied in a direction substantially orthogonal to the liquid crystal molecules in the liquid crystal layer in the direction of the orientation state of the liquid crystal molecules. Therefore, a transition nucleus is generated in the disclination line, and the transition from the splay orientation to the bend orientation can be rapidly performed.

According to a twentieth aspect of the present invention, in the liquid crystal display device according to the seventeenth aspect, the orientation direction of the alignment film is perpendicular to a signal electrode line or a gate electrode line along the pixel electrode. It is characterized by being slightly deviated from the direction.

The orientation direction of the alignment film is slightly deviated from a direction perpendicular to the signal electrode line or the gate electrode line, so that the disclination line is shifted from the signal electrode line or the gate electrode line. Is applied obliquely, and a twisting force is applied to the liquid crystal molecules in the splay alignment, so that the transition to the bend alignment is easily performed.

The invention according to claim 21 is the liquid crystal display device according to claim 17, wherein the second voltage has a frequency in the range of 0.1 Hz to 100 Hz, and
Duty ratio of at least 1: 1 to 100
It is characterized by a pulse-like voltage in the range of 0: 1.

By applying the pulsed second voltage as described above and alternately repeating the voltage application period and the period in which the voltage is not applied, the liquid crystal molecules are oscillated and easily transitioned. The aligned liquid crystal molecules transition to bend alignment. The reason why the frequency and the duty ratio are regulated in the above ranges is to expand a transition region from the splay alignment to the bend alignment.

The invention according to claim 22 is the liquid crystal display device according to any one of claims 17 to 21, wherein the gate electrode line is in a high state at least during most of the transition period. It is characterized by.

In the disclination line region, the strain energy is higher than that of the surroundings. In this state, a horizontal electric field is applied to the disclination line also from the gate electrode line arranged beside the pixel electrode. As a result, energy is further applied, and the transition from the splay alignment to the bend alignment is quickly performed.

According to a twenty-third aspect of the present invention, in the liquid crystal display device according to any one of the seventeenth to twenty-first aspects, at least one of the alignment films formed on the inner surface side of the pixel electrode and the common electrode. The liquid crystal cell is characterized by having a liquid crystal cell which is divided by irradiating a part of the region of the alignment film with ultraviolet rays to change the pretilt angle of the liquid crystal in the alignment film.

By irradiating a part of the alignment film with ultraviolet light, the surface of the alignment film in the region irradiated with ultraviolet light is modified, and the pretilt angle of the liquid crystal in the modified alignment film is reduced to a small value. can do. The reason why the pretilt angle of the liquid crystal in the alignment film is reduced by the irradiation of the ultraviolet light is not clear at present, but it is considered that the side chain existing on the surface of the alignment film is cut by the ultraviolet light. In this manner, a liquid crystal cell whose orientation is divided by irradiation with ultraviolet rays can be easily formed.

According to a twenty-fourth aspect of the present invention, there is provided the liquid crystal display device according to any one of the seventeenth to twenty-first aspects, wherein a part of the pixel electrode and the common electrode is irradiated with ultraviolet rays in an ozone atmosphere. After planarizing at least a part of at least one of the pixel electrode and the common electrode, an alignment film is applied and baked on the pixel electrode and the common electrode, and a pretilt of liquid crystal in the alignment film is performed. It is characterized by having a liquid crystal cell whose orientation is divided by changing the angle.

By irradiating a partial area of the pixel electrode and the common electrode with ultraviolet light in an ozone atmosphere, the surfaces of the pixel electrode and the common electrode can be flattened. Then, by applying an alignment film, the pretilt angle of the liquid crystal in the alignment film can be changed to easily form a liquid crystal cell having the alignment division.

According to a twenty-fifth aspect of the present invention, the pretilt angles of the liquid crystal at the upper and lower interfaces of the liquid crystal layer disposed between the array substrate having the pixel electrodes and the counter substrate having the common electrode are opposite in polarity.
In a splay alignment liquid crystal cell that is aligned in parallel with each other, it is in a splay alignment when no voltage is applied, and prior to driving the liquid crystal display, an initialization process of transitioning from the splay alignment to the bend alignment by applying a voltage is performed, In the method of manufacturing an active matrix type liquid crystal display device that performs liquid crystal display driving in this initialized bend alignment state,
Preparing step for preparing a splay-aligned liquid crystal cell in which the pretilt angles of liquid crystals at the upper and lower interfaces of a liquid crystal layer disposed between an array substrate having pixel electrodes and a counter substrate having a common electrode are oppositely oriented and parallel to each other. A first voltage for forming a disclination line is applied between the pixel electrode and the common electrode, and a disc is formed near a boundary between the first liquid crystal cell region and the second liquid crystal cell region. A disclination line forming step of forming a ligation line, and applying a second voltage higher than a first voltage between the pixel electrode and the common electrode, thereby forming a first liquid crystal cell region and a second liquid crystal cell region. An alignment transition step of generating a transition nucleus in a disclination line near a boundary with a liquid crystal cell region and transitioning from splay alignment to bend alignment.

According to the above-mentioned method, in the liquid crystal display device, the splay-bend alignment transition is caused to occur at a certain place (near a disclination line) in each pixel region where a large number of liquid crystal cells are formed. In addition, the dislocation energy is higher in the vicinity of the disclination line than in the surroundings, so that a transition nucleus is definitely generated. Therefore, it is possible to surely cause the alignment transition quickly, and to obtain a liquid crystal display device having excellent image quality without display defects.

The invention according to claim 26 is the method for manufacturing a liquid crystal display device according to claim 25, wherein the preparing step includes:
In a partial area of one pixel, the liquid crystal molecules are b-spray aligned by performing an alignment process such that the pretilt angle of the liquid crystal on the pixel electrode side is smaller than the pretilt angle of the liquid crystal on the common electrode side, In the other region of the one pixel, by performing an alignment process so that the pretilt angle of the liquid crystal on the pixel electrode side is larger than the pretilt angle of the liquid crystal on the common electrode side, t-splay alignment of the liquid crystal molecules is performed. It is characterized by including a processing step.

According to the above method, b-
A splay alignment region and a t-splay alignment region are formed,
Disclination lines are clearly formed at the boundaries. As described above, since the energy of the strain is higher in the vicinity of the disclination line than in the surroundings, a transition nucleus is reliably generated, and therefore, the orientation transition can be surely caused quickly.

The invention according to claim 27 is the method for manufacturing a liquid crystal display device according to claim 26, wherein the alignment treatment step is formed on an inner surface side of at least one of the pixel electrode and the common electrode. It is characterized in that a partial region of the alignment film thus formed is irradiated with ultraviolet rays to change the pretilt angle of the liquid crystal to perform alignment division.

By irradiating a part of the alignment film with ultraviolet light, the surface of the alignment film in the region irradiated with the ultraviolet light is modified, and the pretilt angle of the liquid crystal in the modified alignment film is reduced to a small value. can do.

According to a twenty-eighth aspect of the present invention, in the method for manufacturing a liquid crystal display device according to the twenty-sixth aspect, the aligning step is performed by partially removing at least one of the pixel electrode and the common electrode. After irradiating ultraviolet rays in an ozone atmosphere to planarize a partial area of the pixel electrode and the common electrode, apply and bake an alignment film on the pixel electrode and the common electrode, It is characterized in that the orientation is divided by changing the pretilt angle.

According to the above-mentioned method, at least a part of at least one of the pixel electrode and the common electrode can be flattened. Therefore, the alignment film is coated on the pixel electrode and the common electrode. This makes it possible to obtain a liquid crystal display device having a liquid crystal cell in which the alignment is divided by changing the pretilt angle of the liquid crystal in the alignment film.

According to a twenty-ninth aspect of the present invention, there is provided a splay liquid crystal cell in which the pretilt angles of the liquid crystal at the upper and lower interfaces of the liquid crystal layer between the array substrate and the counter substrate are opposite to each other, and are aligned in parallel with each other. Sometimes it is in a splay alignment, and prior to driving the liquid crystal display, an initialization process for changing from the splay alignment to the bend alignment by applying a voltage is performed,
In an active matrix type liquid crystal display device that drives a liquid crystal display in this initialized bend alignment state, 1
In the pixel, has at least one horizontal electric field application unit for transition excitation, and generates a horizontal electric field by the horizontal electric field application unit, and continuously or intermittently applies a voltage between the pixel electrode and the common electrode, It is characterized in that a transition nucleus is generated for each pixel and the entire pixel is transitioned from the splay alignment to the bend alignment.

According to the above configuration, the following operation is performed.

A voltage that is sufficiently higher than the transition voltage is applied between the pixel electrode and the common electrode, and at least one lateral excitation applying section provided in one pixel applies a lateral electric field to the liquid crystal layer. As a result, the horizontal electric field applying portion serves as a starting point from the splay alignment to the bend alignment of the liquid crystal layer in the pixel (that is, a transition nucleus can be reliably generated in the liquid crystal layer around the horizontal electric field applying portion). The orientation can be changed from the splay orientation to the bend orientation.

The invention according to claim 30 is the liquid crystal display device according to claim 29, wherein the direction of the horizontal electric field generated by the horizontal electric field applying section is substantially orthogonal to the alignment processing direction. And

With the above configuration, a horizontal electric field is applied from the horizontal electric field applying section in a direction substantially orthogonal to the alignment state direction of the liquid crystal molecules in the liquid crystal layer. Accordingly, a transition nucleus is generated, and the orientation can be rapidly transferred from the splay orientation to the bend orientation.

According to a thirty-first aspect of the present invention, in the liquid crystal display device according to the twenty-ninth aspect, the lateral electric field applying portion is configured such that a peripheral portion of the pixel electrode is deformed into irregularities in a plane parallel to the substrate surface. It is characterized by being a deformed part.

According to the above configuration, the following operation is performed.

A lateral electric field applying portion composed of an electrode deformed portion in which the periphery of the pixel electrode is deformed irregularly in a plane parallel to the substrate surface, and a signal electrode line or a gate electrode line present on the side of the lateral electric field applying portion Therefore, the horizontal electric field generated in that case is stronger than the horizontal electric field generated between the pixel electrode having no horizontal electric field applying portion and the signal electrode line or the gate electrode line. Therefore, a transition nucleus can be surely generated in the liquid crystal layer by the lateral electric field generated by the presence of the lateral electric field application unit, and the transition from the splay alignment to the bend alignment can be rapidly performed.

According to a thirty-second aspect of the present invention, in the liquid crystal display device according to the twenty-ninth aspect, the lateral electric field applying section deforms the signal electrode lines or the gate electrode lines into irregularities in a plane parallel to the substrate surface. Characterized in that it is an electrode wire deformed portion.

The following operation is performed by the above configuration.

The same function as that of the invention according to the thirty-first aspect is achieved by the presence of the electrode wire deformed portion of one or both of the electrode wires.

According to a thirty-third aspect of the present invention, in the liquid crystal display device according to the twenty-ninth aspect, the lateral electric field applying section deforms a peripheral portion of the pixel electrode into irregularities in a plane parallel to the substrate surface. It is characterized by an electrode / electrode line deformed portion in which a signal electrode line or a gate electrode line is unevenly deformed in accordance with unevenness.

According to the above configuration, the following operation is performed.

An electrode / electrode in which at least one side of a pixel electrode is deformed in a plane parallel to the substrate surface in a peripheral portion thereof, and correspondingly, a signal electrode line or a gate electrode line or both of them are unevenly deformed. The same effect as that of the thirty-first aspect is performed by the horizontal electric field applying part which is a line deformation part.

According to a thirty-fourth aspect of the present invention, in the liquid crystal display device according to the twenty-ninth aspect, the horizontal electric field applying section deforms the horizontal electric field applying line into irregularities in a plane parallel to the substrate surface. A horizontal electric field application line deforming portion, wherein the horizontal electric field application line is
At least one of the signal electrode line and the gate electrode line is disposed in the same direction via an insulating film in an upper layer or a lower layer via an insulating film, and is connected to a drive circuit to which the signal electrode line or the gate electrode line is connected. I have.

According to the above configuration, the horizontal electric field applying line is a line exclusively for applying a horizontal electric field, and is provided on at least one of the signal electrode line and the gate electrode line or the lower layer via an insulating film. Therefore, there is flexibility in the shape such as continuous formation of irregularities on the side of the horizontal electric field application wire. Further, since the horizontal electric field application line overlaps the signal electrode line or the gate electrode line, light absorption is small, and therefore, the aperture ratio of the pixel does not decrease. Therefore, it is possible to make a redundant design with a degree of freedom in design.

According to a thirty-fifth aspect of the present invention, in the liquid crystal display device according to the thirty-fourth aspect, the horizontal electric field application line is cut off from the drive circuit during normal liquid crystal display after the alignment transition. And

With the above configuration, the horizontal electric field application line is cut off from the drive circuit during the normal liquid crystal display after the alignment transition. In this case, the horizontal electric field application line formed on the horizontal electric field application line is formed. No lateral electric field is generated between the application section and the pixel electrode. Therefore, at the time of normal liquid crystal display, the liquid crystal alignment is not disturbed, and a liquid crystal display device showing a good liquid crystal display state can be obtained.

According to a thirty-sixth aspect of the present invention, there is provided a splay-aligned liquid crystal cell in which the pretilt angles of the liquid crystal at the upper and lower interfaces of the liquid crystal layer between the array substrate and the opposing substrate are opposite to each other and are aligned in parallel with each other. Sometimes it is in a splay alignment, and prior to driving the liquid crystal display, an initialization process for changing from the splay alignment to the bend alignment by applying a voltage is performed,
In an active matrix type liquid crystal display device that drives a liquid crystal display in this initialized bend alignment state, 1
The pixel is characterized by having at least one of a pixel electrode or a common electrode in which a defect is formed in at least one place for applying a lateral electric field for transfer excitation.

According to the above configuration, the following operation is performed.

Since each pixel has at least one of a pixel electrode or a common electrode having a defect formed in at least one location for applying a transverse electric field for transfer excitation, the edge of the defect has an electric field distortion. (Oblique electric field) is generated.
Therefore, the liquid crystal molecules are subjected to a twisting force by the oblique electric field, so that transition nuclei are surely generated, and the transition from the splay alignment to the bend alignment is accelerated.

The invention according to claim 37 is a splay alignment liquid crystal cell in which the pretilt angles of the liquid crystal at the upper and lower interfaces of the liquid crystal layer between the array substrate and the counter substrate are opposite to each other and are aligned in parallel with each other. Sometimes it is in a splay alignment, and prior to driving the liquid crystal display, an initialization process for changing from the splay alignment to the bend alignment by applying a voltage is performed,
In an active matrix type liquid crystal display device that drives a liquid crystal display in this initialized bend alignment state, 1
In the pixel, there is provided a horizontal electric field applying portion for transfer excitation, and in one pixel, a pretilt angle of liquid crystal molecules in a partial region of the pixel electrode indicates a first pretilt angle, and a common electrode facing the pixel electrode. A first alignment region having a second pretilt angle in which the pretilt angle of the liquid crystal molecules in a partial region is larger than that;
The pretilt angle of the liquid crystal molecules in the other area of the pixel electrode is 3rd.
And a second alignment region having a fourth pretilt angle smaller than the pretilt angle of liquid crystal molecules in another part of the common electrode facing the pixel electrode. I have.

The following operation is performed by the above configuration.

Since the operation of the horizontal electric field applying section and the pre-tilt angle differ between the first alignment region and the second alignment region,
A disclination line is generated between the first and second orientation regions, and the disclination line becomes a starting point of the orientation transition, thereby promoting the transition from the splay orientation to the bend orientation.

According to a thirty-eighth aspect of the present invention, in the liquid crystal display device according to any one of the twenty-ninth to thirty-seventh aspects, the frequency between the common electrode and the pixel electrode ranges from 0.1 Hz to 100 Hz.
It is characterized in that it has a pulse voltage application unit for applying a pulse-like voltage in a range of Hz and a duty ratio in a range of at least 1: 1 to 1000: 1.

The following operation is performed by the above configuration.

Although there are some differences depending on the size and shape of the pixel, the thickness of the liquid crystal layer, etc., the frequency and the duty ratio of the pulse voltage applying section are restricted to the above ranges because the transition from the splay alignment to the bend alignment is performed. This is to enlarge the area.

By applying the pulsed second voltage as described above and alternately repeating the voltage application period and the period in which no voltage is applied, the liquid crystal molecules are oscillated and easily transitioned. The aligned liquid crystal molecules transition to bend alignment. The reason why the frequency and the duty ratio are regulated in the above ranges is to expand a transition region from the splay alignment to the bend alignment.

The invention according to claim 39 includes a liquid crystal layer sandwiched between a pair of substrates, and a phase compensator disposed outside the substrates, wherein when no voltage is applied, the liquid crystal layer has a liquid crystal at the upper and lower interfaces. The pre-tilt angle of the liquid crystal layer is opposite to the pre-tilt angle, and the liquid crystal layer is in a splay alignment in which the liquid crystal layer is aligned in parallel with each other. And
In a liquid crystal display device that performs liquid crystal display driving in the initialized bend alignment state, the display pixel includes at least one region having a smaller liquid crystal layer thickness than the surroundings, and an electric field applied to the liquid crystal layer in the region. The intensity is higher than the electric field intensity applied to the surrounding liquid crystal layer.

According to the above configuration, transition nuclei are easily generated in a portion where the electric field intensity is large, and the transition time can be shortened.

Further, the invention according to claim 40 includes a liquid crystal layer sandwiched between a pair of substrates, and a phase compensator disposed outside the substrates, wherein when no voltage is applied, the liquid crystal layer has an upper and lower interface. The liquid crystal has a splay alignment in which the pretilt angles of the liquid crystal are opposite to each other and are aligned in parallel with each other, and prior to driving the liquid crystal display, initialization is performed to transfer the alignment state of the liquid crystal layer from the splay alignment to the bend alignment by applying a voltage. In a liquid crystal display device which performs a process and drives a liquid crystal display in this initialized bend alignment state, the liquid crystal display device includes at least one region having a small liquid crystal layer thickness outside a display pixel, and an electric field applied to the liquid crystal layer in the region. The intensity is higher than the intensity of the electric field applied to the in-pixel liquid crystal layer.

With the above configuration, electric field concentration occurs outside the pixel, and the transition nucleus generated outside the pixel propagates into the pixel. Therefore, even in such a case, the transition time can be shortened.

Further, the invention according to claim 41 includes a liquid crystal layer sandwiched between a pair of substrates, and a phase compensator disposed outside the substrates, and when no voltage is applied, the liquid crystal layer has upper and lower interfaces. The liquid crystal has a splay alignment in which the pretilt angles of the liquid crystal are opposite to each other and are aligned in parallel with each other, and prior to driving the liquid crystal display, initialization is performed to transfer the alignment state of the liquid crystal layer from the splay alignment to the bend alignment by applying a voltage. In a liquid crystal display device which performs a process and drives a liquid crystal display in this initialized bend alignment state, the display pixel includes at least one electric field concentration portion.

The invention according to claim 42 is the invention according to claim 41.
In the liquid crystal display element described above, the electric field concentration portion provided in the display pixel is a display electrode partially protruding in a thickness direction of a liquid crystal layer, or a part of a common electrode, or both. .

With the protruding display electrode configuration as described above,
An electric field concentration portion can be configured. And claim 4
The invention described in 3 is a liquid crystal layer sandwiched between a pair of substrates;
A phase compensator disposed outside the substrate, and when no voltage is applied, the liquid crystal layer has a splay alignment in which the pretilt angles of the liquid crystal at the upper and lower interfaces are opposite to each other, and the liquid crystal layer is aligned in parallel with each other. Prior to the display driving, the liquid crystal display device performs an initialization process of changing the alignment state of the liquid crystal layer from the splay alignment to the bend alignment by applying a voltage, and performs liquid crystal display driving in the initialized bend alignment state. It is characterized by including at least one electric field concentration site outside the pixel.

By providing the electric field concentration portion outside the display pixel as described above, the transition nucleus generated outside the pixel propagates into the pixel. Therefore, even in such a case, the transition time can be shortened.

The invention according to claim 44 is the invention according to claim 43.
3. The liquid crystal display device according to claim 1, wherein the electric field concentration portion is a part of an electrode partially projecting in a thickness direction of the liquid crystal layer.

Further, the invention according to claim 45 includes a liquid crystal layer sandwiched between a pair of substrates, and a phase compensator disposed outside the substrates, and when no voltage is applied, the liquid crystal layer has an upper and lower interface. The liquid crystal has a splay alignment in which the pretilt angles of the liquid crystal are opposite to each other and are aligned in parallel with each other, and prior to driving the liquid crystal display, initialization is performed to transfer the alignment state of the liquid crystal layer from the splay alignment to the bend alignment by applying a voltage. In a liquid crystal display device which performs a process and drives a liquid crystal display in this initialized bend alignment state, an opening is provided in a display electrode, a part of a common electrode, or both.

According to the above configuration, the transition time can be shortened.

According to a forty-sixth aspect of the present invention, in the liquid crystal display device of the forty-fifth aspect, the opening comprises a display electrode formed on a flattening film of the active matrix type liquid crystal display device including a switching element and the switching element. It is a conduction port electrically connected to the element.

According to the above configuration, the transition time can be shortened.

The invention according to claim 47 is the same as the claim 39.
47. The liquid crystal display device according to any one of Items 46 to 46, wherein the phase compensating plate is a phase compensating plate including at least one phase compensating plate made of an optical medium having a negative refractive index anisotropy and having a main axis hybridly arranged. It is characterized by the following.

The invention according to claim 48 is the invention according to claim 47.
In the liquid crystal display device described above, the phase compensator is a phase compensator including at least one positive phase compensator.

An invention according to claim 49 is a method for applying an electric field to a liquid crystal held between a first substrate and a second substrate facing each other to change the orientation of the liquid crystal to bend orientation. The splay elastic constant k11 of the liquid crystal is set to 10
× 10 ⁻⁷ dyn ≧ k11 ≧ 6 × 10 ⁻⁷ dyn
When the absolute value of the pretilt angle of the liquid crystal with respect to the first substrate is θ1, and the absolute value of the pretilt angle of the liquid crystal with respect to the second substrate is θ2, 1.57r
ad> | θ1−θ2 | ≧ 0.0002 rad.

With this configuration, the critical electric field of the liquid crystal transition can be reduced, and the alignment state of the liquid crystal molecules can be rapidly changed from the initial state to the bend alignment.

The invention according to claim 50 is a method for applying an electric field to a liquid crystal held between a first substrate and a second substrate opposed to each other to change the orientation of the liquid crystal to bend orientation. The splay elastic constant k11 of the liquid crystal is set to 10
× 10 ⁻⁷ dyn ≧ k11 ≧ 6 × 10 ⁻⁷ dyn
The electric field is an electric field in which a spatially uniform applied main electric field is superimposed on a spatially non-uniformly applied auxiliary electric field, and the main electric field is E0, and the maximum value of the auxiliary electric field is Is defined as E1, the relationship 1.0> E1 / E0> 1/100 is satisfied.

With such a configuration, the critical electric field of the liquid crystal transition can be reduced, and the alignment state of the liquid crystal molecules can be quickly shifted from the initial state to the bend alignment.

The invention according to claim 51 is a method for applying an electric field to a liquid crystal held between a first substrate and a second substrate opposed to each other to change the orientation of the liquid crystal to a bend orientation. When the absolute value of the pretilt angle of the liquid crystal with respect to the first substrate is θ1 and the absolute value of the pretilt angle of the liquid crystal with respect to the second substrate is θ2,
57 rad> | θ 1 −θ 2 | ≧ 0.0002 rad, and the electric field is obtained by superimposing a spatially non-uniformly applied auxiliary electric field on a spatially uniformly applied main electric field. When the main electric field is E0 and the maximum value of the sub electric field is E1, 1.0> E1 / E0> 1 /
100.

With such a configuration, the critical electric field of the liquid crystal transition can be reduced, and the alignment state of the liquid crystal molecules can be quickly shifted from the initial state to the bend alignment.

The invention according to claim 52 is a method for applying an electric field to a liquid crystal held between a first substrate and a second substrate facing each other to change the orientation of the liquid crystal to a bend orientation. The splay elastic constant k11 of the liquid crystal is 10 ×
^10-7 dyn ≧ k11 ≧ 6 × 10 ⁻⁷ dyn, the absolute value of the pretilt angle of the liquid crystal with respect to the first substrate is θ1, and the absolute value of the pretilt angle of the liquid crystal with respect to the second substrate is θ1. When θ2, 1.57 rad> |
The relationship of θ1−θ2 | ≧ 0.0002 rad is satisfied, and the electric field is a main electric field that is applied spatially uniformly.
An electric field obtained by superimposing a sub electric field applied in a spatially non-uniform manner, wherein the main electric field is E0, and the maximum value of the sub electric field is E1.
Satisfies the relationship of 1.0> E1 / E0> 1/100.

With such a configuration, the critical electric field of the liquid crystal transition can be reduced, and the alignment state of the liquid crystal molecules can be promptly shifted from the initial state to the bend alignment.

The pretilt angle is the orientation angle of the liquid crystal molecules in contact with each substrate surface before applying an electric field. The tilt of the molecular axis of the liquid crystal molecules in contact with the substrate surface with respect to a plane parallel to the substrate is defined as the pretilt angle. The angle is expressed in a range of -π / 2 to π / 2 rad, taking a plane as a reference (= 0) as a positive counterclockwise direction. Further, a pretilt angle of the liquid crystal with respect to the first substrate and a pretilt angle of the liquid crystal with respect to the second substrate are angles having different signs.

The invention according to claim 53 is the same as that in claim 5
53. The method of driving a liquid crystal display device according to any one of 0 to 52, wherein the sub-electric field is applied to a source electrode or a gate electrode of a thin film transistor formed on a surface of the first substrate and to a surface of the second substrate. The electric field is applied between the formed transparent electrode.

The invention according to claim 54 is the same as that in claim 5
The driving method of a liquid crystal display device according to any one of Items 0 to 53, wherein the auxiliary electric field is an AC electric field that is attenuated and vibrated with the passage of time.

[0124]

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a bend-oriented OCB.
In a liquid crystal display device provided with a cell, it was obtained as a result of paying attention to a transition mechanism from splay alignment to bend alignment described below. Therefore, first, the transfer mechanism will be described in detail, and then the specific contents of the present invention will be described using embodiments.

FIG. 1 is a perspective view showing a part of a liquid crystal display device having a bend alignment type OCB cell. With reference to FIG. 1, the structure of a liquid crystal display device including a bend alignment type OCB cell will be briefly described.
A liquid crystal layer 13 containing liquid crystal molecules 12 is inserted between 0 and 11. Although not shown in the figure, display electrodes for applying an electric field to the liquid crystal layer 13 and alignment films for regulating the alignment of liquid crystal molecules are formed on the surfaces of the substrates 10 and 11 facing each other. I have. As shown in the figure, the alignment film is pre-tilted the liquid crystal molecules 12 near the substrate interface by about 5 to 7 degrees, and is subjected to an alignment process so that the alignment directions in the substrate surface are mutually the same direction, that is, parallel alignment. . As the distance from the surfaces of the substrates 10 and 11 increases, the liquid crystal molecules 1
2 gradually rises to bend alignment in which the tilt angle of liquid crystal molecules is 90 degrees at almost the center in the thickness direction of the liquid crystal layer 13. Polarizing plates 15 and 1 are provided outside the substrates 10 and 11.
6 and optical compensators 17 and 18 are arranged. The two polarizing plates 15 and 16 are arranged so that their polarization axes are orthogonal or parallel to each other, and the polarization axis and the orientation of liquid crystal molecules have an angle of 45 degrees. It is arranged to become. Then, utilizing the difference in the refractive index anisotropy of the liquid crystal layer between the on state where a high voltage is applied and the off state where a low voltage is applied, the polarization state is changed through the above-mentioned polarizing plate and optical compensator to change the polarization state of light. The display is controlled by controlling the transmittance.

In a liquid crystal display device having the above-described bend alignment type OCB cell, the liquid crystal layer is in a splay alignment state before use. Therefore, prior to driving the liquid crystal display, the liquid crystal layer is shifted from the splay alignment state by applying a voltage. It is necessary to make transition to the bend alignment state.

FIG. 2 schematically shows the mechanism of the alignment transition from the splay alignment to the bend alignment of the liquid crystal layer when a high voltage equal to or higher than the critical transition voltage is applied due to the alignment transition.

FIG. 2 is a sectional view of a liquid crystal cell schematically showing liquid crystal molecules and conceptually showing a liquid crystal molecule arrangement when two substrates are arranged in parallel alignment.

FIG. 2A shows an initial splay arrangement state. When there is no electric field between the substrates, the major axis of the liquid crystal molecules 12 in the center of the liquid crystal layer 13 is in a splay alignment state with a low energy state, which is almost parallel to the substrate surface. Here, for convenience of explanation, liquid crystal molecules parallel to the substrate are denoted by reference numeral 12a.

Next, FIG. 2B shows a liquid crystal molecular alignment state when a high voltage is applied between electrodes (not shown) formed on the substrates 10 and 11. The liquid crystal molecules 12 in the center of the liquid crystal layer 13 begin to slightly tilt due to the electric field, and as a result, the liquid crystal molecules 12a oriented parallel to the substrate surface move toward one substrate surface (toward the substrate 11 in the figure). Go.

Next, FIG. 2C shows the state of the liquid crystal molecule alignment when a further time has elapsed after the application of the voltage. Liquid crystal layer 1
The liquid crystal molecules 12 at the center of 3 are further inclined with respect to the substrate surface, whereas the liquid crystal molecules 12a oriented substantially parallel to the substrate surface come near the substrate interface and exert a strong regulating force from the alignment film. receive.

Next, FIG. 2 (d) shows a liquid crystal molecule alignment state in which the transition to bend alignment has a much higher energy state.
The liquid crystal molecules 12 in the center of the liquid crystal layer 13 are perpendicular to the substrate surface, and the liquid crystal molecules in contact with the interface of the alignment film (not shown) on the substrate 10 receive a strong regulating force from the alignment film to be tilted. The state is maintained, and at this time, the liquid crystal molecules 12a oriented parallel to the substrate surface existing in FIGS. 2A to 2C almost disappear.

If the time further elapses than in FIG. 2D, the above-mentioned alignment state shifts to the bend alignment state shown in FIG. 1 between the substrates, and the transition is completed.

As described above, the situation where the transition from the splay alignment to the bend alignment that occurs when a voltage is applied is considered as described above.

However, the place where this occurs usually does not occur all at once in the entire liquid crystal layer within the substrate surface, but is a part where energy can easily move in a part of the alignment region, and is usually dispersed in the gap. A transition nucleus is generated in the peripheral portion of the spacer or an uneven alignment portion, and a bend alignment region is expanded from the nucleus. Therefore, in order to cause the orientation transition in the OCB cell, a transition nucleus is generated in at least a part of the liquid crystal layer in the substrate plane, and a bend orientation state having higher energy than the splay alignment state by applying energy from the outside. To maintain this.

As a result of considering the mechanism of the alignment transition, the inventors of the present invention have found that a liquid crystal display device capable of surely generating a transition nucleus and completing the transition in a very short time, a method of manufacturing the same, and a liquid crystal display device. The driving method was completed. Specific contents will be described based on the embodiment.

(Embodiment 1) FIG. 3 is a conceptual diagram showing a configuration of a pixel unit by a driving method of a liquid crystal display device according to Embodiment 1 of the present invention. First, with reference to FIG.
Of the liquid crystal display device related to the driving method according to the above. The liquid crystal display device according to the first embodiment has the same configuration as that of a liquid crystal display device including a general OCB cell, with respect to a configuration excluding a drive circuit unit. That is, it has a pair of glass substrates 20 and 21 and a liquid crystal layer 26 sandwiched between the glass substrates 20 and 21. Glass substrates 20, 21
Are arranged facing each other with a certain interval. A common electrode 22 made of an ITO transparent electrode is formed on the inner surface of the glass substrate 20.
A pixel electrode 23 made of a transparent electrode of TO is formed. On the common electrode 22 and the pixel electrode 23, alignment films 24 and 25 made of a polyimide film are formed, and the alignment films 24 and 25 are aligned so that the alignment directions are parallel to each other. Then, the alignment films 24 and 25
A liquid crystal layer 26 made of a P-type nematic liquid crystal is inserted between them. Further, the pretilt angle of the liquid crystal molecules on the alignment films 24 and 25 is set to about 5 degrees, and the critical voltage for transition from the splay alignment to the bend alignment is set to 2.5V. The retardation of the optical compensator 29 is selected so as to display white or black when in the ON state. In FIG. 1, reference numerals 27 and 28 denote polarizing plates.

In the figure, reference numeral 30 denotes a driving circuit for orientation transition, and reference numeral 31 denotes a driving circuit for liquid crystal display. Also, 32
Reference numerals a and 32b denote switch circuits, and reference numeral 33 denotes a switch control circuit that controls switching of the switching mode of the switch circuits 32a and 32b. The switch circuit 32a includes:
The switch circuit 32b includes two individual contacts P3 and P4 and one common contact Q2. The switch circuit 32b includes two individual contacts P1 and P2 and one common contact Q1.
The common contact Q1 is connected to one of the individual contacts P1 and P2 according to the switch switching signal S1 from the switch control circuit 33. Similarly, the common contact Q2 is connected to one of the individual contacts P3 and P4 according to the switch switching signal S2 from the switch control circuit 33. When the common contact Q1 is connected to the individual contact P1 and the common contact Q2 is connected to the individual contact P3, the drive voltage from the orientation transition drive circuit 30 is applied to the electrodes 22 and 23. When the common contact Q1 is connected to the individual contact P2 and the common contact Q2 is connected to the individual contact P4, the driving voltage from the liquid crystal display driving circuit 33 is applied to the electrode 2
2, 23 will be applied.

Next, a driving method according to the first embodiment will be described.

First, prior to liquid crystal display driving based on an original image signal, an initialization process is performed for transition to bend alignment. First, when the power is turned on, the switch control circuit 3
3 outputs the switch switching signals S1 and S2 to the switch circuits 32a and 32b, and connects the common contact Q1 to the individual contact P1 and connects the common contact Q2 to the individual contact P3. As a result, the orientation transition driving circuit 30 can be used as shown in FIG.
Is applied between the electrodes 22 and 23. This drive voltage is an AC voltage in which the AC rectangular wave voltage A is superimposed on the bias voltage B as shown in FIG. 4, and the value of the drive voltage is necessary for causing the transition from the splay alignment to the bend alignment. It is set to a voltage value higher than the critical voltage which is the minimum voltage. By applying such a drive voltage, the transition time can be remarkably shortened as compared with the conventional example in which a simple AC voltage is applied. The reason why the transition time is short will be described later. In this way, the initialization processing regarding the transition to the bend alignment is completed.

Next, when the transition time for the entire electrode to completely transition to the bend orientation elapses, the switch control circuit 33 switches the switching signal S for switching the common contact Q1 to the individual contact P2 side.
1 to the switch circuit 32a and the common contact Q
A switching signal S2 for switching 2 to the individual contact P4 is output to the switch circuit 32b. As a result, the common contact Q1 and the individual contact P2 are connected, and the common contact Q2 and the individual contact P4 are connected. The drive signal voltage from the liquid crystal display drive circuit 31 is applied between the electrodes 22 and 23. The desired image is displayed. Here, the driving circuit 31 for liquid crystal display has a rectangular wave voltage of 30 Hz of 2.7.
V, the bend alignment state is maintained, this is turned off, the rectangular wave voltage 7V of 30 Hz is turned on, and the OC
Panel B was displayed.

Next, the present inventor manufactured a liquid crystal display device having the above-described configuration, and performed an experiment of an initialization process using the above-described driving method. The results will be described. The experimental conditions are as follows.

The electrode area was 2 cm ² , the cell gap was about 6 μm, the frequency of the AC rectangular wave voltage A was 30 Hz, and the amplitude was ± 4 V.

Under the above conditions, the bias voltage B is set to 0
V, 2 V, 4 V, and 5 V were set, and the transition times were measured. The results are shown in FIG. 5. Here, the transition time means the time required for completing the orientation transition in the entire area of the electrode area.

As is clear from FIG. 5, when the bias voltage B was 0 V, the transition time required 140 seconds. On the other hand, when the bias voltage B was 4 V, the transition time could be reduced to 8 seconds. This is because, due to the superposition of the bias voltage, the orientation of the liquid crystal molecules in the liquid crystal layer is fluctuated by the bias voltage, so that a shift occurs between the substrates as shown in FIG. It is thought that the transfer time became faster with the up.

As described above, by continuously applying the bias-superimposed AC voltage, the transition time can be shortened as compared with the case of simple AC voltage application.

In the above experimental example, the AC rectangular wave voltage signal has a frequency of 30 Hz and a value of ± 4 V. However, the present invention is not limited to this, and any frequency at which the liquid crystal operates can be used, for example, 10 kHz. Of course, the transition time can be shortened by increasing the amplitude of the AC voltage A. At this time, the higher the bias voltage B is superimposed, the higher the speed. However, in consideration of lowering the drive voltage, it is desirable to set the bias voltage to an optimal voltage level according to a desired transition time. Although a rectangular wave is used as a waveform, an AC waveform having a different duty ratio may be used.

(Embodiment 2) FIG. 6 is a conceptual diagram of a pixel unit of a liquid crystal display device according to Embodiment 2. In the second embodiment, a step of applying an AC voltage on which a bias voltage is superimposed is applied between the substrates and a step of electrically opening the substrates (open state) are alternately repeated.
The liquid crystal layer is changed from a splay alignment to a bend alignment.

In the liquid crystal display device according to the second embodiment, the same components as those in the liquid crystal display device according to the first embodiment are denoted by the same reference numerals, and description thereof is omitted. In the second embodiment, the driving circuit 3 for orientation transition according to the first embodiment is used.
0, the switch circuit 32a, and the switch control circuit 32, instead of the orientation transition drive circuit 40 and the switch circuit 42.
a and the switch control circuit 43 are used. The switch circuit 42a includes an individual contact P in addition to the individual contacts P1 and P2.
5 is a three-terminal changeover switch circuit. The switching of the switch circuit 42a is controlled by a switch control circuit 43. The drive circuit 40 for orientation transition applies the drive voltage shown in FIG. This drive voltage is an AC voltage in which an AC rectangular wave voltage C is superimposed on a bias voltage D as shown in FIG. 7, and the value of the drive voltage is necessary to cause a transition from the spray orientation to the bend orientation. It is set to a voltage value higher than the critical voltage which is the minimum voltage.

The common contact Q1 of the switch circuit 42a
Is a switch switching signal S3 from the switch control circuit 42.
As a result, it is in a state of being connected to any of the individual contacts P1, P2, P5. In a state where the common contact Q1 is connected to the individual contact P5, the electrodes 22 and 23 are in an open state separated from the alignment transition drive circuit 40. In a state where the common contact Q1 is connected to the individual contact P1 and the common contact Q2 is connected to the individual contact P3, the drive voltage from the orientation transition drive circuit 40 is applied to the electrodes 22 and 23. When the common contact Q1 is connected to the individual contact P2 and the common contact Q2 is connected to the individual contact P4, the drive voltage from the liquid crystal display drive circuit 31 is applied to the electrodes 22 and 23.

Next, a driving method according to the second embodiment will be described.

First, prior to driving the liquid crystal display based on the original image signal, an initialization process is performed for transition to bend alignment. First, when the power is turned on, the switch control circuit 4
3 outputs a switch switching signal S3 to the switch circuit 42a, outputs a switch switching signal S2 to the switch circuit 32b, connects the common contact Q1 and the individual contact P1, and connects the common contact Q2 and the individual contact P3 to each other. Is connected. Thus, the drive voltage shown in FIG. 7 is applied between the electrodes 22 and 23 from the drive circuit 30 for orientation transition. Then, when a certain period T2 elapses, the switch control circuit 43
Outputs the switch switching signal S3 to the switch circuit 42a to connect the common contact Q1 and the individual contact P5.
As a result, the electrodes 22 and 23 are connected to the drive circuit 4 for orientation transition.
It is disconnected from 0 and becomes open. Such an open state is maintained for a period W2, and during this open state period W2, the state between the electrodes 22 and 23 is in a charge holding state.

After the elapse of the open state period W2, the switch control circuit 43 outputs a switch switching signal S3 to the switch circuit 42a to reconnect the common contact Q1 and the individual contact P1. The drive for the orientation transition and the open state are alternately repeated, and after a certain period of time from when the power is turned on, the entire surface of the electrode completely transitions to the bend orientation.

When the fixed period has elapsed, the switch control circuit 43 outputs the switch switching signal S3 to the switch circuit 42a and the switch switch signal S2 to the switch circuit 32b, and outputs the common contact Q1 and the individual contact P2.
And the common contact Q2 and the individual contact P43
And are connected. Thereby, the liquid crystal display driving circuit 3
1 is applied between the electrodes 20, 21;
The desired image is displayed. Here, the driving circuit 31 for the liquid crystal display has 30H as in the first embodiment.
The zigzag rectangular wave voltage of 2.7 V is used to maintain the bend alignment state and turn it off, and the 30 Hz rectangular wave voltage of 7 V is turned on to display the OCB panel.

Next, the present inventor manufactured a liquid crystal display device having the above configuration, and conducted an experiment of an initialization process by the above driving method. The results will be described. The experimental conditions are as follows.

The electrode area was 2 cm ² , the cell gap was about 6 μm, the bias voltage B was 2 V, the frequency and amplitude of the AC rectangular wave voltage D were 30 Hz, ± 4 V,
The application time T2 was fixed at 2 seconds.

Under the above conditions, the open state time W
2 was changed to 0 seconds, 0.2 seconds, 2 seconds, and 3 seconds, and the transition time when the voltage application state and the open state were alternately measured was measured. The results are shown in FIG. here,
The transition time means the time required for completing the orientation transition in the entire area of the electrode area.

As apparent from FIG. 8, when the open state time W2 was 0 seconds, that is, when the AC voltage with the bias voltage superimposed was applied continuously, the transition time required 80 seconds. On the other hand, when the open state time W2 was set to 0.2 second and the switching was repeated alternately with the bias-superimposed AC voltage, the transition time was shortened to 40 seconds. However, when the open state time W2 was set to 2 seconds, the transfer time was lengthened to 420 seconds, and when W2 was set to 3 seconds, the transfer could not be completed.

The transition time was 28 seconds when the transition time was measured under the same conditions as in the above experimental example except that the application time T2 was 0.3 seconds and the open state period W2 was 0.3 seconds.

By the way, when T2 was fixed at 2 seconds and W2 was set at 0.1 seconds or more and 0.5 seconds or less, good results were obtained.

The reason why the state transition time from the splay alignment to the bend alignment is extremely shortened by repeatedly switching between the biased AC voltage and the open state as described above is considered to be as follows. That is, the application of the bias-superimposed AC voltage causes the liquid crystal molecule alignment of the liquid crystal layer to be shaken, causing a deviation between the substrates as shown in FIG. 2 (d) and disturbing them. It is considered that this occurred and the transposition time became faster.

The effect can be obtained even before or after the step of applying the bias-superimposed AC voltage, by further applying another voltage signal and then entering the open state.

Further, the voltage value of the bias voltage or the AC voltage,
The application time and the time for maintaining the open state can be selected according to the desired transition time. The frequency of the AC voltage may be any frequency at which the liquid crystal operates, for example, 10 kHz.
A value such as z may be used. Although the rectangular wave is used as the waveform, an AC waveform having a different duty ratio may be used.

(Embodiment 3) FIG. 9 is a conceptual diagram of a pixel unit configuration of a liquid crystal display device according to Embodiment 3. In the third embodiment, the step of applying an AC voltage on which a bias voltage is superimposed is applied between the substrates and the step of applying a zero voltage or a low voltage between the substrates are alternately repeated, so that the liquid crystal layer is shifted from the splay alignment. It is characterized in that transition to bend orientation is performed.

In the liquid crystal display device according to the third embodiment, the same components as those in the liquid crystal display device according to the second embodiment are denoted by the same reference numerals, and description thereof is omitted. In the third embodiment, the switch circuit 32b of the second embodiment,
And a switch circuit 42 instead of the switch control circuit 43.
b and the switch control circuit 53 are used. In the third embodiment, in addition to the alignment transition drive circuit 40,
A drive circuit 50 for orientation transition for applying a low voltage between the electrodes 22 and 23 is provided.

The switch circuit 42b includes an individual contact P
3, a three-terminal switch circuit including an individual contact P6 in addition to P4. The switching of the switch circuit 42b is controlled by a switch control circuit 53. The common contact Q2 of the switch circuit 42b is turned on by a switch switching signal S4 from the switch control circuit 53.
It is in a state of being connected to any of the individual contacts P3, P4, P6.

The common contact Q1 is connected to the individual contact P5,
In a state where the common contact Q2 is connected to the individual contact P3, the drive voltage from the orientation transition drive circuit 40 is applied to the electrode 2
2, 23 will be applied. Also, the common contact Q1
Are connected to the individual contact P5 and the common contact Q2 is connected to the individual contact P6.
Is applied to the electrodes 22 and 23. Further, when the common contact Q1 is connected to the individual contact P2 and the common contact Q2 is connected to the individual contact P4, the drive voltage from the liquid crystal display drive circuit 31 is applied to the electrodes 22 and 23.

Next, a driving method according to the third embodiment will be described.

First, prior to liquid crystal display driving based on an original image signal, an initialization process is performed for transition to bend alignment. First, when the power is turned on, the switch control circuit 5 is turned on.
3 outputs a switch switching signal S3 to the switch circuit 42a, outputs a switch switching signal S4 to the switch circuit 42b, connects the common contact Q1 and the individual contact P1, and connects the common contact Q2 and the individual contact P3 to each other. Is connected. As a result, the orientation transition drive circuit 40 can
Is applied between the electrodes 22 and 23. When a certain period T3 has elapsed, the switch control circuit 53
Outputs the switch switching signal S3 to the switch circuit 42a and outputs the switch switching signal S3 to the switch circuit 42b.
4 is output, the common contact Q1 and the individual contact P5 are connected, and the common contact Q2 and the individual contact P6 are connected. As a result, the low voltage shown in FIG. 10 is applied between the electrodes 22 and 23 from the alignment transition drive circuit 50. Such a low voltage application is maintained for the period W3.

Next, when the low voltage application period W3 has elapsed,
The switch control circuit 53 outputs a switch switching signal S3 to the switch circuit 42a and outputs a switch switching signal S4 to the switch circuit 42b, again connecting the common contact Q1 and the individual contact P1 and connecting the common contact Q2 and the individual contact P3 is connected. Then, the alternating voltage application process and the low voltage application process are alternately repeated, and after a certain period of time from when the power is turned on, the entire surface of the electrode completely transitions to the bend orientation.

After the elapse of this predetermined period, the switch control circuit 53 outputs the switch switching signal S3 to the switch circuit 42a and the switch switch signal S4 to the switch circuit 42b, and outputs the common contact Q1 and the individual contact P2.
And the common contact Q2 and the individual contact P43
And are connected. Thereby, the liquid crystal display driving circuit 3
1 is applied between the electrodes 20, 21;
The desired image is displayed. Here, the driving circuit 31 for the liquid crystal display has 30H as in the first embodiment.
The zigzag rectangular wave voltage of 2.7 V is used to maintain the bend alignment state and turn it off, and the 30 Hz rectangular wave voltage of 7 V is turned on to display the OCB panel.

Next, the present inventor manufactured a liquid crystal display device having the above configuration, and conducted an experiment of an initialization process by the above driving method. The results will be described. The experimental conditions are as follows.

The electrode area was 2 cm ² , the cell gap was about 6 μm, the bias voltage D was 2 V, the frequency and amplitude of the AC rectangular wave voltage C were 30 Hz, ± 4 V,
The application time T3 was fixed at 1 second. The applied voltage during the low voltage application period W3 was a DC voltage of -2V.

Under the above conditions, the low voltage application period W3
Was changed, and the transition time when the alternating voltage applied state and the applied voltage applied state were alternately repeated was measured. The result is shown in FIG.

As is apparent from FIG. 11, when the low voltage application time was 0 second, that is, when the AC voltage with the bias voltage superimposed was continuously applied, the transition time required about 80 seconds. On the other hand, when the low voltage application time W3 was set to 0.1 second and the voltage was alternately switched with the bias superimposed AC voltage, the transition time was reduced to 60 seconds. However, when the low voltage application time W3 was set to 1 second, the transition time was long, 360 seconds, and when W3 was set to 3 seconds, the transition could not be completed.

Further, in the switching repetition between the AC voltage ± 4 V in which the bias voltage was superimposed by 2 V and the DC voltage of 0 V, the transition was completed within 50 seconds at the shortest. In addition, in the switching repetition between the AC voltage ± 4 V with the bias of 2 V superimposed and the AC low voltage ± 2 V, a transition time of 50 seconds or less was obtained at the shortest.

By the way, when T3 was fixed at 1 second and W2 was set at 0.1 seconds or more and 0.5 seconds or less, good results were obtained.

The transition time from the splay alignment to the bend alignment can be obtained by repeatedly switching between the application of the biased AC voltage and the application of the low voltage as compared with the case where the AC voltage with the bias is simply applied continuously as described above. Becomes shorter. This is because the liquid crystal molecule alignment of the liquid crystal layer is fluctuated by the application of an AC voltage with a bias superimposed, and the liquid crystal layer is moved between the substrates as shown in FIG.
It is considered that the displacement occurs as shown in FIG. 3 and the disturbance occurs, and then the transition to a short low-voltage application state generates a transition nucleus, thereby shortening the transition time.

Also, the voltage value of the bias voltage or the AC voltage,
The application time, low voltage value, application time, and the like are not the above values, but can be selected and changed according to the desired transition time.
The frequency of the AC voltage may be a frequency at which the liquid crystal operates, and may be, for example, a value such as 10 kHz. Although the rectangular wave is used as the waveform, an AC waveform having a different duty ratio may be used.

In the above example, the low voltage of -2 V is applied during the low voltage application period W3, but 0 V may be applied.

Next, the ratio between the AC voltage application period T3 and the low voltage application period W3 and the number of repetitions of the AC voltage application and the low voltage application per second will be described. Here, for convenience of explanation, the voltage in the low voltage application period W3 is set to 0V,
The alternate repetition of the application of the AC voltage and the application of 0 V is considered as one transition voltage as shown by a broken line L in FIG. In such a case, in order to shorten the transition time, it is necessary to set the frequency of the transition voltage L in the range of 0.1 Hz to 100 Hz and the duty ratio of the transition voltage L in the range of 1: 1 to 1000: 1. There is. Further, the frequency of the transition voltage L is
It is desirable that the duty ratio of the transition voltage L be in the range of 0.1: 1 to 10 Hz and the duty ratio of the transition voltage L be in the range of 2: 1 to 1000: 1. Hereinafter, the reason will be described in detail.

In the range of the duty ratio where the duty ratio of the repetitively applied voltage is larger in the voltage application suspension period than in the voltage application period (for example, in the range of duty ratio 1: 1 to 1:10), the pulse width application is performed. It is considered that even if a transition nucleus is generated, the transition is relaxed in a state where the application of the voltage at the pulse interval is stopped and the state returns to the splay orientation, and the transition is not completed. Therefore, it is necessary to set the duty ratio in such a range that the voltage application period is longer than the voltage application suspension period. In order to expand the transition region, the duty ratio is 1: 1 where the pulse width is wider than the pulse interval.
To 1000: 1, preferably 2: 1 to 10
0: 1 is better. In the case of DC continuous from 1000: 1, since pulse repetition is hardly applied, it is considered that the chance of generating transition nuclei decreases and the transition becomes slightly longer.

The repetition frequency of the application of the transition voltage is preferably from continuous to about 100 Hz. Preferably, from 10 Hz at which a pulse width of about 100 ms or more can be obtained for expansion of the transition, about 10 ms or more at a duty ratio of 1000: 1. The pulse interval is preferably up to 0.1 Hz.

The present inventor measured the transition time when a voltage was applied to the liquid crystal cell while changing the repetition frequency and the duty ratio under alternating repetition conditions of DC-15 V and 0 V. It is shown in FIG.

[Table 1]

As is clear from Table 1, when the frequency is 0.1
The transition time is very short when the frequency is in the range from 0.1 Hz to 100 Hz and the duty ratio is in the range from 1: 1 to 1000: 1 when the duty ratio is in the range from 2 Hz to 10 Hz and the duty ratio is in the range from 2: 1 to 1000: 1. Even in the case of the range, it is recognized that the transition time is sufficiently small.

(Embodiment 4) FIG. 12 is a conceptual diagram showing the configuration of a pixel unit of a liquid crystal display device according to Embodiment 4. Embodiment 4 shows an example in which the present invention is applied to a driving method of an active matrix liquid crystal display device.

First, referring to FIG. 12, Embodiment 4
Of the liquid crystal display device related to the driving method according to the above. The liquid crystal display device according to the fourth embodiment has the same configuration as that of an active matrix type liquid crystal display device including a general OCB cell, except for a drive circuit unit. That is, it has a pair of glass substrates 60 and 61 and a liquid crystal layer 66 sandwiched between the glass substrates 60 and 61. The glass substrates 60 and 61 are opposed to each other with a certain interval. ITO on the inner surface of the glass substrate 60
A common electrode 62 made of a transparent electrode is formed. On the inner surface of the glass substrate 61, a thin film transistor (TFT) 70 as a pixel switching element and a pixel electrode 63 made of an ITO transparent electrode connected to the TFT 70 are formed. ing. On the common electrode 62 and the pixel electrode 63, alignment films 64 and 65 made of a polyimide film are formed, and the alignment films 64 and 65 are aligned so that the alignment directions are parallel to each other. And the alignment film 6
A liquid crystal layer 66 made of a P-type nematic liquid crystal is inserted between the layers 4 and 65. The pretilt angle of the liquid crystal molecules on the alignment films 64 and 65 is set to about 5 degrees, and the critical voltage for transition from the splay alignment to the bend alignment is 2.6.
V is set. The retardation of the optical compensator 67 is selected so as to display white or black when in the ON state. In the figures, 68 and 69 are polarizing plates.

In the figure, reference numerals 71 and 72 denote alignment transition drive circuits.
2 functions to apply a drive voltage with reference to the center of the common electrode shown in FIG. 14 and apply 0 V to the pixel electrode 63. Note that, as another configuration, the drive circuit 72 for orientation transition
Functions to apply 0 V to the common electrode 62 and the pixel electrode 63. Reference numeral 73 denotes a liquid crystal display driving circuit. The liquid crystal display driving circuit 73 has a function of applying a driving voltage having a voltage waveform shown in FIG. 13 to the common electrode 62 and the pixel electrode 63. That is, the liquid crystal display drive circuit 73 applies the voltage indicated by reference numeral M1 in FIG. 13 to the pixel electrode 63 and applies the voltage indicated by reference numeral M2 in FIG. In the above configuration, during the orientation transition period,
Although 0 V is applied to the pixel electrode 63, the pixel electrode voltage may be applied from the liquid crystal display drive circuit 73 even during the alignment transition period instead.

Reference numerals 74a and 74b denote switch circuits, and reference numeral 75 denotes a switch control circuit that controls switching of the switching modes of the switch circuits 74a and 74b. The switch circuit 74a includes three individual contacts P7, P8, P
9 and one common contact Q1. The switch circuit 74b includes three individual contacts P10, 11, 12
And one common contact Q2. The common contact Q1 is connected to the individual contact P7 and the common contact Q2 is connected to the individual contact P
In the state of being connected to 10, the drive voltage from the orientation transition drive circuit 71 is applied to the electrodes 62 and 63. When the common contact Q1 is connected to the individual contact P2 and the common contact Q2 is connected to the individual contact P4, the driving voltage from the liquid crystal display driving circuit 73 is applied to the electrodes 62 and 63.
Will be applied.

Next, a driving method according to the fourth embodiment will be described.

First, prior to liquid crystal display driving based on an original image signal, an initialization process is performed for transition to bend alignment. First, when the power is turned on, the switch control circuit 7 is turned on.
5 outputs a switch switching signal to the switch circuit 74a and outputs a switch switch signal to the switch circuit 74b to connect the common contact Q1 and the individual contact P7,
In addition, the common contact Q2 and the individual contact P10 are connected.
As a result, the drive voltage shown in FIG. 14 is applied to the common electrode 62 from the alignment transition drive circuit 71. That is, the common electrode 62 has a bias voltage −
An AC voltage in which the GV is superimposed and synchronized with the vertical synchronization signal is applied. Note that 0 V is applied to the pixel electrode. Then, the application of the AC voltage is maintained for a period T4.

Next, after the elapse of the AC voltage application period T4, the switch control circuit 75 outputs a switch switching signal to the switch circuit 74a and switches the switch circuit 74b.
To output a switch signal, connect the common contact Q1 and the individual contact P9, and connect the common contact Q2 and the individual contact P
12 is connected. As a result, 0 V is applied to the common electrode 62 and the pixel electrode 63 from the alignment transition drive circuit 72 as shown in FIG. Then, this 0 V voltage application is maintained for the period W4.

Next, when the 0 V voltage application period W4 has elapsed, the switch control circuit 75 outputs a switch switching signal to the switch circuit 742a and outputs a switch switching signal to the switch circuit 74b, and the common contact Q1 and the individual contact P7 are again connected. Are connected, and the common contact Q2 and the individual contact P10 are connected. Then, the alternating voltage application step and the 0 V voltage application step are alternately repeated, and when a certain period has elapsed since the power was turned on, the entire surface of the electrode completely transitions to the bend orientation.

Then, after the elapse of the predetermined period, the switch control circuit 75 outputs a switch switching signal to the switch circuit 74a and outputs a switch switching signal to the switch circuit 74b to connect the common contact Q1 and the individual contact P8. And the common contact Q2 and the individual contact P11 are connected. As a result, the drive signal voltage from the liquid crystal display drive circuit 73 is applied to the electrodes 62 and 63, and a desired image is displayed. Here, the liquid crystal display drive circuit 73 sets the drive voltage 2.7 V for maintaining the bend alignment state between the two electrodes to a minimum, turns it off, sets the upper limit voltage to 7 V, turns it on, and sets the OCB to OCB. Display the panel.

By the above driving method, an OCB active matrix type liquid crystal display device of a bend alignment type having a wide field of view and a high speed response was able to perform high quality driving display without any alignment defect.

Next, the present inventor manufactured a liquid crystal display device having the above configuration, and conducted an experiment of an initialization process by the above driving method. The results will be described. The experimental conditions are as follows.

The cell gap is about 6 μm, the bias voltage G is -6 V, the frequency and amplitude of the AC rectangular wave voltage are 7.92 kHz, ± 10 V, and the application time T3 is 0.5
Seconds. Further, the 0 V voltage application period W4 was set to 0.5 seconds.

According to the above experimental results, the alignment transition in all the pixels of the panel of the liquid crystal display device could be completed within about 2 seconds.

When the bias voltage was not superimposed, it took about 20 seconds to change the alignment state of the entire display surface. Therefore, it is recognized that, in the fourth embodiment as well, driving by superimposing a bias voltage can achieve a reduction in transition time.

(Embodiment 5) As a driving method relating to the orientation transition of an OCB mode active matrix liquid crystal display device, the driving voltage waveform shown in FIG. 15 is used instead of the driving voltage waveform shown in FIG. You may make it. That is, in the AC voltage application period T4, the DC voltage -15 is applied to the common electrode 62 with respect to the center of the common electrode.
V is applied for 0.5 seconds. Next, the 0V voltage application period W
In No. 4, 0 V is applied for 0.2 seconds. Then, the application of the DC voltage of −15 V and the application of the 0 V voltage are alternately repeated.
Even in such a driving method, the transfer can be completed reliably and in a very short time.

When the inventor conducted an experiment using the above driving method, a transition time of less than 2 seconds was obtained.

(Embodiment 6) In Embodiment 6, instead of the active matrix type liquid crystal display device used in Embodiments 4 and 5, a flattening film is arranged on a switching element. The present invention is characterized in that the driving methods of the fourth and fifth embodiments are applied to a liquid crystal display device having a so-called flattening film structure in which a pixel electrode is formed thereon. More specifically, the driving method was such that the bias-superimposed voltage for orientation transition in Embodiment 4 was applied for 0.5 seconds, and then the open state was set for 0.5 seconds, and this was repeated alternately. According to this driving method, the transition time was less than 1 second, and the transition was smoother. This is considered to be due to the fact that the pixel electrode interval can be reduced by the flattening film configuration, and as a result, the transition from the splay alignment to the bend alignment smoothly occurs.

(Other Matters) In the above embodiment, an AC voltage with a bias voltage superimposed thereon is applied. However, a DC voltage may be applied. In this case, a unipolar voltage is applied. For this reason, the driving circuit can be simplified.

In the above-described embodiment, the AC voltage signal on which the bias voltage is superimposed has been described as a DC bias voltage, but a low-frequency AC signal may be used for improving reliability.

The optimum ranges of the frequency and duty ratio of the repetitive voltage can be applied to other embodiments other than the third embodiment.

In the above embodiments, the driving method of the liquid crystal display device of the present invention has been described with reference to the transmission type liquid crystal display device. However, a reflection type liquid crystal display device may be used. These may be a full-color liquid crystal display device using a color filter or a liquid crystal display device without a color filter.

Embodiment 7 FIG. 16 is a schematic sectional view of a liquid crystal display device according to Embodiment 7 of the present invention, and FIG. 17 is a schematic plan view thereof. The liquid crystal display device shown in FIG. 16 includes polarizing plates 101 and 102, a phase compensator 103 for optical compensation disposed inside the polarizing plate 101, and an active matrix disposed between the polarizing plates 101 and 102. Liquid crystal cell 104. The liquid crystal cell 1
Reference numeral 04 denotes an array substrate 106 made of glass or the like, and a counter substrate 105 facing the array substrate 106. A pixel electrode 108 as a transparent electrode is formed on an inner surface of the array substrate 106. A common electrode 107 is formed on the inner surface of the element 105. Further, the pixel electrode 1
The alignment film 110 is formed on the common electrode 108, and the alignment film 109 is formed on the common electrode 107.

Further, on the array substrate 106, a switching element 111 composed of, for example, an a-Si type TFT element is arranged, and the switching element 111 is connected to the pixel electrode 108.

A spacer (not shown) having a diameter of 5 μm and a liquid crystal layer 11 made of a nematic liquid crystal material having a positive dielectric anisotropy are provided between the alignment films 109 and 110.
2 are arranged. Also, the alignment films 109 and 110
Are parallel-aligned in the same direction so that the pretilt angles of the liquid crystal molecules on the surface thereof are opposite to each other, and are substantially parallel to each other. Therefore, the liquid crystal layer 112 forms a so-called splay alignment composed of an alignment region in which liquid crystal molecules are obliquely spread in a state where no voltage is applied.

Further, the alignment film 110 has a large pretilt angle B2 (third pretilt angle).
a and the orientation film 110b having a small pretilt angle A2 (first pretilt angle). Further, the alignment film 10
Reference numeral 9 denotes an alignment film 109a having a small pretilt angle D2 (fourth pretilt angle) and a large value pretilt angle C2.
It is composed of the (second pretilt angle) alignment film 109b, and the pretilt angle C2 is arranged opposite the pretilt angle A2, and the pretilt angle D2 is arranged opposite the pretilt angle B2.

The alignment films 109 and 110 are subjected to a parallel alignment process in a direction substantially perpendicular to the signal electrode lines 113 by a rubbing cloth in the same direction as the upper and lower substrates (from left to right in FIG. 16).

Although not shown, the liquid crystal display device is provided with an alignment transition drive circuit including first voltage application means and second voltage application means, in addition to the liquid crystal display drive circuit. . Then, a first voltage is applied between the pixel electrode 108 and the common electrode 107 by the first voltage applying means, and discrimination is performed near the boundary between the first liquid crystal cell region and the second liquid crystal cell region. Forming a pixel electrode 108 and a counter electrode 10 by a second voltage applying means.
During the period 7, a second voltage higher than the first voltage is applied to generate a transition nucleus in the disclination line, thereby causing a transition from the splay orientation to the bend orientation.

Next, a method for manufacturing this liquid crystal display device will be described.

First, the signal scanning lines 113, the switching elements 111, and the pixel electrodes 1 are formed on the inner surface of the array substrate 106.
08 was formed.

Next, a pretilt angle B as a third pretilt angle having a large value of about 5 degrees of a polyamic acid type manufactured by Nissan Chemical Industries, Ltd. is provided on the pixel electrode 108.
2 was applied, dried and baked to form an alignment film 110 a on the pixel electrode 108.

Next, an ultraviolet ray was irradiated to the left side of the alignment film 110a on the paper surface to change the pretilt angle A2 as the first pretilt angle to a small value of about 2 degrees, thereby forming the alignment film 110b. .

On the inner surface of the counter substrate 105, the common electrode 1
07 was formed.

Next, on the common electrode 107, a pretilt angle C2 as a second pretilt angle having a large value of about 5 degrees of a polyamic acid type manufactured by Nissan Chemical Industries, Ltd.
Is applied to the interfacial liquid crystal molecules, dried and baked, and the alignment film 109b is formed on the common electrode 107.
Was formed.

Next, one side area on the right side of the alignment film 109b (the pretilt angle B having a large pretilt angle).
2) was irradiated with ultraviolet rays to change the pretilt angle D2 as a fourth pretilt angle to a small value of about 2 degrees, thereby forming an alignment film 109a.

As described above, a large pretilt angle C2 (second pretilt angle) is arranged opposite to a small value pretilt angle A2 (first pretilt angle) as shown in FIG. A small pretilt angle D2 (fourth pretilt angle) is opposed to the pretilt angle B2 (third pretilt angle).
Pretilt angle).

The pretilt angle can be controlled as follows.

That is, as shown in FIG. 18A, an active matrix type switching element (not shown) composed of an a-Si type TFT element or the like on the array substrate 106 and a pixel electrode 108 connected thereto. Was formed.

Next, as shown in FIG. 18B, the left region of the pixel electrode 108 is irradiated with ultraviolet rays in an ozone atmosphere, and is flattened as compared with the right region of the pixel electrode 108. 108a was formed.

Next, as shown in FIG. 18C, a pre-mid type polyimide alignment material manufactured by JSR Co., Ltd. is applied on the pixel electrode 108 and dried or fired to form an alignment film 110.
Was formed.

When formed in this manner, the pixel electrode 108
The pretilt angle of the liquid crystal molecules 140 located on the flattened region 108a can be smaller than the pretilt angle of the liquid crystal molecules 140 located on the unflattened region 108b. Further, by performing the same processing for the common electrode, a liquid crystal display device having the first liquid crystal cell region and the second liquid crystal cell region in the same pixel as in FIG. 16 can be obtained. .

Next, as shown in FIG. 16, the alignment film 1 formed as described above and giving a large or small pretilt angle to each other is formed.
The liquid crystal layer 112 made of a positive nematic liquid crystal material is subjected to parallel alignment processing on the surface of the substrate 09 and the alignment film 110 in the same direction (from left to right in FIG. 16) in a direction perpendicular to the signal electrode lines 113 with a rubbing cloth. Was placed.

In the liquid crystal display device thus manufactured, a small pretilt angle A2 is located at the orientation source of the pixel electrode 108 (upstream in the rubbing direction), and a large pretilt angle is located at the opposite side. C2 is located,
When a voltage of 2.5 V is applied as a first voltage between the common electrode 107 and the pixel electrode 108 in the region (a) (first liquid crystal cell region) of the pixel in FIG.
B-spray orientation 120 with splay orientation on the 06 side
However, a t-splay alignment 121 in which liquid crystal molecules are splay-aligned to the counter substrate 105 side is easily formed in the (b) region (second liquid crystal cell region) of the pixel.

That is, as shown in FIGS. 16 and 17, when a voltage of 2.5 V as a first voltage is applied between the common electrode 107 and the pixel electrode 108 through the switching element 111 of the liquid crystal cell 104, b A splay alignment region (first liquid crystal cell region) and a t-splay alignment region (second liquid crystal cell region).
Liquid crystal cell region), and a disclination line 123 is clearly formed at the boundary along the signal electrode line 113 and over the gate electrode lines 114 and 114 ′ (a disclination line forming step). .

Further, by repeatedly applying a voltage -15 V pulse as the second voltage between the common electrode 107 and the pixel electrode 108, a transition nucleus is generated from the disclination line 123 as shown in FIG. Then, the transition to the bend orientation 124 occurred, and the entire TFT panel pixel rapidly transitioned in about 3 seconds (alignment transition step).

This is because the discnation line region, which is the boundary between the b-splay alignment state and the t-splay alignment region, has higher strain energy than its surroundings. In this state, a high voltage is applied between the upper and lower electrodes. It is considered that the energy was further given by this and the splay alignment was changed to the bend alignment.

(Embodiment 8) FIG. 19 is a schematic diagram of a liquid crystal display device according to Embodiment 8 of the present invention.

At the time of normal display, the gate electrode lines are turned on line-by-line and scanning is performed. However, before the normal display, the gate electrode lines are turned on sequentially and the common electrode 107 and the pixel electrode 1 are turned on.
08, a -15 V pulse is repeatedly applied as the second voltage, whereby a horizontal electric field is generated between the pixel electrode 108 and the gate electrode lines 114 and 114 'due to the potential difference. Then, due to the horizontal electric field, the disclination line 123 and the gate electrode lines 114, 1 as shown in FIG.
From around 14 ′, a transition nucleus was generated and the transition was expanded to bend alignment, and the entire TFT panel pixel was expanded to bend alignment more quickly in about 1 second (alignment transition step).

[0233] This is because the disclination line region, which is the boundary between the b-splay alignment state and the t-splay alignment region, has higher strain energy than its surroundings. It is considered that the energy was further given by applying a horizontal electric field to the disclination line from the line, and the line was quickly transferred. After the transition is completed, the gate electrode line 114
114 'returns to the normal scanning state.

Note that the second voltage applied between the pixel electrode and the common electrode may be continuously applied. When a pulsed voltage is repeatedly applied, the frequency is in the range of 0.1 Hz to 100 Hz, and the duty ratio of the second voltage is at least 1: 1 to 1000:
An effect of accelerating the transition is obtained in the range of 1.

(Other Matters) In the seventh and eighth embodiments,
Although the pretilt angle D2 of the orientation region of the common electrode is set to a small value, it may be set to a large value. In addition, the pretilt angle B2 of the alignment destination region of the pixel electrode is set to a large value, but the effect can be obtained even with a small value because the alignment becomes t-splay alignment due to the influence of the lateral electric field.

Also, the pretilt angle C2 opposite to the pretilt angle A2 on one substrate side is set to 5 degrees, but if the ratio is large, the effect of shortening the transfer time is obtained, and the transfer time is further shortened. Can be.

In the above description, the smaller value of the pretilt angle A2 is set to 2 degrees. However, in order to easily transfer to the b-splay alignment and the bend alignment, the smaller values of the pretilt angles A2 and D2 are set to 3 degrees. Degrees or less, and the large pretilt angles B2 and C2 need only be 4 degrees or more.

Although the alignment processing direction is perpendicular to the signal electrode lines 113 and parallel to the upper and lower substrates in the same direction, it is perpendicular to the gate electrode lines 114 (that is, FIG. 1).
6 (perpendicular to the plane of the paper in FIG. 6). At this time, the formation locations of the disclination lines are different.

The direction of the parallel orientation treatment is as follows:
When the alignment process is performed with a deviation of, for example, about 2 degrees from the perpendicular direction of the electrode line along the pixel electrode, a lateral electric field is obliquely applied from the electrode to the disclination line formed in the pixel.
A twisting force is applied to the liquid crystal molecules in the splay alignment, so that the liquid crystal molecules are easily transferred to the bend alignment.

The first voltage may be any voltage as long as it is higher than a voltage at which a disclination line can be formed. Although the second voltage is applied between the pixel electrode and the common electrode, the second voltage may be applied to the common electrode.

Although a polyimide material is used as the alignment film material, other materials such as a monomolecular film material may be used.

In another liquid crystal display device, for example, the substrate can be formed from a plastic substrate. Alternatively, one of the substrates may be formed from a reflective substrate, for example, silicon.

(Embodiment 9) In this embodiment, the signal electrode lines and the pixel electrodes, and the gate electrode lines and the pixel electrodes are formed with irregularities fitting into each other.

FIG. 20 and FIG. 21 conceptually show a main part of the liquid crystal display device of the present embodiment.

This figure shows an active matrix type OC.
FIG. 2 is a view of pixels of a B-mode liquid crystal display device as viewed from above a display surface (user side).

In FIG. 20, 206 is a signal electrode line (bus line), 207 is a gate electrode line, and
8 is a switching transistor (element).

Although the signal electrode line 206 and the gate electrode line 207 intersect in the figure, it goes without saying that both electrode lines are three-dimensionally arranged via an insulating film (not shown).

The switching transistor 208 composed of a TFT is a substantially square pixel electrode 202a in the figure.
It is connected to the. The functions, operations, and functions of the signal electrode line 206, the gate electrode line 207, the switching transistor 208, and the pixel electrode 202a are not different from the conventional liquid crystal display device as well as the OBC mode.

Also, in order to initially align the liquid crystal molecules 211 by spraying, the upper and lower alignment films 203a and 203b are also subjected to alignment using a rubbing cloth or the like.

Further, together with the operation of the polarizing plates 204a and 204b, the entire liquid crystal molecules in the pixel are transferred from the splay alignment state in the pixel to the bend alignment region in which the liquid crystal molecules are in a bend alignment state between the opposing substrates. The same applies to the display of light and dark.

However, as shown in FIG. 20A, a concave portion 221a and a convex portion 222a are formed at substantially the center of each side of the substantially square pixel electrode 202a. On the other hand, the signal electrode line 2 wired close to this
The reference numeral 06 and the gate electrode line 207 are wirings deformed into convex portions 261 and 271 and concave portions 262 and 272 so as to fit into the concave portions 221a and the convex portions 222a. For this reason, the vertical and horizontal positions of the pixel electrode 202a (FIG. 20)
This is different from the conventional liquid crystal display device in that a deformed horizontal electric field applying portion for exciting the transition is formed on the paper surface in (a).

Next, a method of manufacturing this liquid crystal display device will be described.

On the surface of the pixel electrode 202a and the surface of the common electrode 202b including the horizontal electric field applying portion, a polyimide alignment film material of a pre-tilt angle of about 5 degrees of a polyamic acid type manufactured by Nissan Chemical Industries, Ltd. Is applied, dried and baked, and alignment films 203a and 203 are formed on the liquid crystal layer 210 side of each electrode surface.
b was formed.

Next, the surfaces of the alignment films 203a and 203b were subjected to an alignment process using a rubbing cloth in a direction substantially orthogonal to the signal electrode lines 206 as shown in FIG.

Based on the above, a liquid crystal layer 210 was formed by vacuum injection of a positive nematic liquid crystal material between the upper and lower substrates.

Although not shown, the upper and lower alignment films 20
On the surfaces of 3a and 203b, the liquid crystal molecules 211 are oriented so that the pretilt angles thereof are opposite to each other in positive and negative directions, and the molecular axes are almost parallel to each other. This is a so-called splay alignment in which molecules are spread obliquely.

Next, the operation for display of the liquid crystal display device will be described.

Based on the above, in the liquid crystal field of -15 V between the common electrode 202b and the pixel electrode 202a, a pulse-like voltage having a relatively high voltage is repeatedly applied, and the gate electrode line 207 is set in a normal scanning state. Alternatively, almost all are turned on. As a result, the horizontal electric field applying unit applies a horizontal electric field stronger than the surrounding normal electric field between the gate electrode line 207, the signal electrode line 206, and the pixel electrode 202a. As a result, when rubbing is performed in a direction substantially perpendicular to the signal electrode line 206 in the splay alignment region in the pixel region, the gate electrode line 207 and the pixel electrode 202
A transition nucleus to bend alignment is generated in the liquid crystal layer 299 starting from the horizontal electric field application portion between a. In addition, as shown in FIG. 21, when rubbing is performed in a direction orthogonal to the gate electrode line 207, the liquid crystal layer 298 mainly has a horizontal electric field application portion between the signal electrode line 206 and the pixel electrode 202a as a base point. Metastatic nuclei occur.

Further, the bend alignment region was expanded based on the transition nucleus, and as a result, the entire pixel region could be completed to the bend alignment in about 0.5 seconds.

In the entire TFT panel, the transition was rapid in about 2 seconds.

In this mechanism, when a high voltage is applied between the upper and lower electrodes, as shown in FIG.
Is in the b-splay alignment state, the energy of the strain is higher than that of the surroundings, and a horizontal electric field is applied substantially perpendicularly (in the direction perpendicular to the plane of FIG. 20B) from the horizontal electric field application section in the liquid crystal molecule alignment state direction. It is considered that the liquid crystal molecules on the lower substrate side in the b-spray alignment in FIG. 20B receive a twisting force, and the generation of transition nuclei occurs.

In the above description, the horizontal electric field applying portion is formed such that the pixel electrode portion deformed into a concave and a concave portion of both signal electrode lines are fitted to each other. As shown, only the pixel electrode 202a is connected to the signal electrode line 206.
Of course, only the gate electrode line 207 may be formed.

That is, in the figure, the signal electrode lines 206
The projection 263 of the gate electrode line 207, the projection 223a of the pixel electrode 202a, and the projection 223a of the pixel electrode 202a are provided in only one of them, which is different from that shown in FIG.

The planar shape of the concave / convex portion may be a shape other than the triangular shape and the square shape shown in FIGS. 20 to 22, for example, a trapezoidal shape, a semicircular shape, a circular shape, an elliptical shape, and the like. It is.

Further, in FIGS. 20 to 22, four horizontal electric field applying portions are provided at a total of four places on the upper, lower, left and right sides of one pixel. However, depending on the size of the pixel, only two upper or lower parts or only one horizontal electric field applying section are provided. Of course, irregularities may be formed continuously along the edge of the electrode. Although the rubbing direction has been described as being substantially perpendicular to the signal electrode lines or the gate electrode lines, the rubbing direction may be an oblique direction. In this case, transition from the liquid crystal layer of the horizontal electric field applying portion between the signal and the gate electrode line and the pixel electrode to the bend alignment occurs. In addition, it is desirable to arrange at least one horizontal electric field application unit that can apply a horizontal electric field in a direction substantially orthogonal to the rubbing direction for each pixel.

Since FIGS. 20 to 22 are plan views, both electrode lines (signal electrode line 206 and gate electrode line 2) are shown.
07) and the pixel electrode 202a appear to be on the same plane, but at least one of the electrode lines may be arranged at a different height from the pixel electrode and the array substrate.

As described above, the horizontal electric field applying portion including the electrode deformed portion in which a part of the periphery of the pixel electrode is deformed into irregularities in a plane parallel to the substrate surface is separated by about 0.5 to 10 μm in plan view. A lateral electric field is generated by the presence of a convex portion of the signal electrode line or the gate electrode line or a concave portion recessed by about 0.5 to 10 μm present on the side of the lateral electric field application section.

(Embodiment 10) In this embodiment, an electrode line for applying a lateral electric field is provided.

Hereinafter, the present embodiment will be described with reference to FIG.

(A) of this figure is a plan view seen from the upper surface of the substrate. (B) shows a gate electrode line 207 of the liquid crystal display device.
FIG. 3 is a cross-sectional view taken on a plane parallel to FIG.

In FIGS. 27A and 27B, 209
Is an electric wire laid almost exclusively under the signal electrode line 206 on the array substrate 201a exclusively for applying a horizontal electric field. 21
2 is the horizontal electric field application line 209 and the signal electrode line 206;
This is a transparent insulating film for insulating the gate electrode lines 207 and the like. Therefore, when this pixel is viewed from above (in the direction of the user orthogonal to the display surface), as shown in FIG. A convex part 291 having a shape protrudes to the side of the signal electrode line 206. The signal electrode line 206 and the pixel electrode 202a are not different from those of the prior art.

The horizontal electric field applying line 209 is connected to a driving circuit to which the signal electrode line 206 or the gate electrode line 207 is connected.
Are configured to be cut off from the drive circuit during normal liquid crystal display after the alignment transition.

Further, the horizontal electric field applying line 209 is used as an upper signal electrode line with respect to the signal electrode line 206 and is provided close to the pixel electrode via a transparent insulating film to increase the effect of applying the horizontal electric field. It may be electrically connected by a contact hole (not shown) in the transparent insulating film. in this case,
Since there are two signal electrode lines, there is also an effect that redundancy is increased and electric resistance is reduced.

That is, as shown in FIG. 23C, the horizontal electric field application line 209 a is provided directly above the signal electrode line 206 via the transparent insulating film 213. It is the same that there is a projection 291a having a triangular shape in plan view to the pixel center.

FIG. 23D shows another example of the present embodiment. As shown in FIG.
Is covered with a flattening transparent insulating film 212b, and further, the signal electrode line 206 is covered with a flattening transparent insulating film 212c below the dedicated line 209b, and the pixel electrode 202a
Is provided on the flattened transparent insulating film 212b. It is the same that there is a triangular projection 291b to the pixel center.

In the figure, the convex portion of the dedicated line for applying a horizontal electric field is formed in a triangular shape. However, the convex portion is continuously provided on all the portions facing the pixel electrodes, and furthermore, projects upward. Needless to say, it may have a three-dimensional structure such as having a convex portion.

The dedicated line for applying the horizontal electric field may be provided directly below or directly above the gate electrode line instead of the signal electrode line. Further, it may be provided immediately below both electrode wires.

(Embodiment 11) In this embodiment, a defective portion is formed by providing at least one notch in a pixel electrode.

FIG. 24 conceptually shows a plane and features of a pixel unit of the liquid crystal display device of the present embodiment. As shown in the figure, a pixel electrode 202a made of an ITO film has a thickness of, for example, several μm.
The electrode defect portion 225 having a m-width and being removed by etching is formed in a crank shape in a plan view.

The surface of the pixel electrode 202a including the electrode defect portion 225 and the surface of the common electrode (not shown) are formed by a pre-tilt of about 5 degrees of a polyamic acid type manufactured by Nissan Chemical Industries, Ltd. A polyimide alignment film material of a corner is applied, dried and baked to form an alignment film (not shown),
Further, their surfaces are rubbed with a gate electrode line 20.
In the ninth and tenth embodiments, the alignment processing is performed in the direction perpendicular to the direction 7 and the pretilt angles of the liquid crystal molecules are opposite to each other in the positive and negative directions, and the liquid crystal molecules are aligned in the same direction so as to be almost parallel to each other. This is the same as the embodiment.

Therefore, the liquid crystal layer also forms a so-called splay-aligned liquid crystal cell comprising an alignment region in which liquid crystal molecules are obliquely spread in a so-called no-voltage application state.

However, a pulse of 15 V or a voltage of −15 V was repeatedly applied between the common electrode and the pixel electrode of the pixel before display, and the gate electrode was turned on in a normal scanning state or almost completely turned on. In the state, since the electrode defect portion 225 exists in the pixel unit,
As shown in FIG. 24B, an oblique horizontal electric field 280 with strong distortion is generated at the edge of the electrode defect portion 225.

Therefore, the splay orientation in the pixel region is
A transition nucleus to bend alignment is generated in the liquid crystal layer 299 of the electrode defect portion 225, and the bend alignment region is further expanded to complete the entire pixel region to bend alignment in about 0.5 seconds. Further, the entire TFT panel is quickly transferred in about 2 seconds.

In this case, a strong horizontal electric field is applied in the horizontal electric field applying section consisting of the electrode defective portion 225, and the liquid crystal molecules in the vicinity of the electric field are horizontally aligned on the substrate surface, so-called b-spray alignment state, and distortion from the surroundings is caused. Since the energy is high and a high voltage is applied between the upper and lower electrodes under this state, more energy is given. As a result, transition nuclei are generated in the electrode defect portion 225, and the bend alignment region is enlarged. It is considered something.

In FIG. 24, one electrode defective portion 225 having a crank shape in plan view is formed, but it is needless to say that two or more electrode defective portions 225 may be formed.

Further, the shape may of course be a straight line, a square, a circle, an ellipse, a triangle, or the like.

Further, the electrode defect portion 225 may be formed on the common electrode side.

Further, it goes without saying that it may be formed on both the pixel electrode and the common electrode.

(Embodiment 12) In this embodiment, a horizontal electric field is generated and, at the same time, regions having different tilt angles are formed in the pixel plane in advance.

FIG. 25 conceptually shows the configuration and characteristics of a pixel unit of the liquid crystal display device of the present embodiment. (A) of this figure
Is a sectional view of a pixel in a direction parallel to a gate electrode line,
Although they are the same pixel, the left (a) and the right (b)
This shows how the tilt angles are different.

FIG. 25 (b) is a plan view of the pixel as viewed from the upper (user side) direction. Rough portions 221a and 222a are provided on the upper, lower, left and right sides of the pixel electrode 202a. Concavo-convex portions 261, 262, 271, 272 are provided at positions corresponding to the electrode wires 207 so as to be fitted to the concavo-convex portions 221a, 222a, respectively. 2.5
By applying V, a disclination line 226 is formed at the boundary between (a) and (b) in FIG.

Hereinafter, a method for manufacturing the liquid crystal display device of the present embodiment will be described.

On the inner surface of the substrate facing the liquid crystal cell of the active matrix type, alignment films 203 am and 20 are respectively provided.
3bm, and the alignment films 203am and 203bm
Is that the liquid crystal layer 210 is processed to form a splay alignment in a state where no voltage is applied, and a horizontal electric field applying portion for transfer excitation is applied to the pixel electrode 202a or the gate electrode line 207 wired close to the pixel electrode 202a. Are the same as in the first embodiment.

However, the processing of the alignment film is different. That is, in FIG. 25A, a polyimide alignment of a pre-tilt angle B2 having a large value of about 5 degrees of a polyamic acid type manufactured by Nissan Chemical Industries, Ltd. is provided on the surface of the pixel electrode 202a including the horizontal electric field application unit. The film material is applied, dried and fired to form an alignment film 203am.

Next, only the left side region 203ah of the alignment film 203am, that is, only the one shown in (a) is irradiated with ultraviolet rays to change the pre-tilt angle E2 to an alignment film having a small value of about 2 degrees.

On the other hand, a polyimide alignment film material for imparting a large pretilt angle F2 of about 5 degrees to the interfacial liquid crystal molecules of a polyamic acid type manufactured by Nissan Chemical Industries, Ltd. is coated on the counter substrate 201b. Dried and fired, common electrode 2
An alignment film 203bh is formed on 02b.

Next, only the right side region 203bm of the alignment film 203bh, that is, only the one shown in (b) is irradiated with ultraviolet light to change the alignment film to a small pre-tilt angle D2 of about 2 degrees.

Thus, as shown in FIG. 25A, the alignment film 203a on the left half of the array substrate 201a side is obtained.
The opposing substrate 2 faces the pretilt angle E2 having a small value of h.
A large pre-tilt angle F2 of the alignment film 203bh in the left half of the 01b side is arranged, and as shown in (b), a large pre-tilt angle B2 of the alignment film 203am in the right half of the array substrate 201a is opposed to the large pre-tilt angle B2 of the counter substrate 201b. A pretilt angle D2 of a small value of the alignment film 203bm in the right half is arranged.

Further, the surface of the alignment film thus formed, which gives a large or small pretilt angle, is rubbed with a rubbing cloth in a direction substantially perpendicular to the signal electrode 6 and in the same direction as the upper and lower substrates, as shown in FIG. Parallel orientation treatment was performed. Thereafter, a positive nematic liquid crystal material was filled, and a liquid crystal layer 210 made of the material was arranged.

Under the above, a small pretilt angle E2 is set at the orientation source (the root direction of rubbing) of the pixel electrode 202a.
However, a large pretilt angle F2 is disposed on the side opposite to the pretilt angle E2, and liquid crystal molecules are splay-aligned toward the lower substrate in a region indicated by (a) of the pixel in FIG. The t-splay alignment 227t in which the liquid crystal molecules are spray-aligned toward the upper substrate side is easily formed in the region indicated by (b) of the pixel when the splay alignment 227b is formed.

Next, when 2.5 V near the transition critical voltage is applied between the opposing electrodes through the switching transistor 208 of the liquid crystal cell, b
-A splay alignment region and a t-splay alignment region were formed, and a disclination line 226 was clearly formed along the signal electrode line 206 and over the gate electrode line 207 at the boundary.

[0302] -15 between the common electrode and the pixel electrode of this pixel
A V pulse was repeatedly applied. Then, FIG. 25
As shown in (b), a transition nucleus is generated from the disclination line 226 and the liquid crystal layer 299 near the horizontal electric field application part, and the transition to the bend alignment region is expanded. Transferred to

This is because the declination line 226 is a boundary between the b-splay alignment state and the t-splay alignment region.
In the region, the energy of the strain is higher than that of the surroundings, and in addition to this state, the splay orientation is twisted by the horizontal electric field generated in the horizontal electric field application part and the transition is easy, and the high voltage is applied between the upper and lower electrodes. It is considered that the energy was further applied and the bend transition occurred.

Although the present invention has been described based on several embodiments, it is needless to say that the present invention is not limited to these embodiments. That is, for example, the following may be performed.

1) The voltage applied between the pixel electrode and the common electrode is made continuous or intermittent.

2) When a high voltage pulse is repeatedly applied, its frequency is in the range of 0.1 Hz to 100 Hz, and the duty ratio of the second voltage is at least 1:
Choose a value that speeds up the transition, in the range 1 to 1000: 1.

3) The substrate to be used is made of plastic,
An organic conductive film is used as an electrode.

4) One of the substrates is formed of a reflective substrate, for example, silicon or a reflective substrate formed of a reflective electrode of aluminum or the like to form a reflective liquid crystal display device.

5) Means such as providing a strong electrode electric field generation projection in a direction perpendicular to the substrate surface on the pixel electrode and the common electrode are also used.

6) Instead of spherical glass or silica for keeping the distance between the two substrates constant, a means for forming a projection for this purpose and giving the projection a function of aligning liquid crystal molecules is also used.

7) The upper or lower part of the projection is also used as the projection for generating a strong electrode.

8) The shape of the pixel electrode is not square but
The shape is rectangular or triangular.

9) The pixels are divided into regions having different orientations of liquid crystal instead of two or three or four.

[0314] 10) To change the pretilt angle,
Means such as changing the surface state of the transparent electrode with an O2 asher or the like and forming an alignment film on the transparent electrode is employed.

(Embodiment 13) FIG. 26 shows Embodiment 1 of the present invention.
FIG. 27 is a configuration external view of a liquid crystal cell used in the liquid crystal display device according to No. 3, and FIGS. 27 and 28 are a part of a manufacturing process for explaining the production of a convex-shaped object.

On a glass substrate 308, P made by JSR Corporation was used.
A C-based resist material is applied to form a resist thin film having a thickness of 1 μm. Next, the resist thin film 320 is irradiated and irradiated with parallel ultraviolet rays 323 through a photomask 321 provided with an opening 322 having a rectangular pattern. The resist thin film 320 exposed to the parallel light is developed and rinsed, and 9
Prebaking is performed at 0 ° C. to form a shape 310 having a convex cross section as shown in FIG.

Next, a 2000A ITO film was formed on the substrate according to a standard method to form a glass substrate 308 with electrodes. After that, the glass substrate 30 having the transparent electrode 302
1 and a glass substrate 308 on which the above-mentioned convex object is formed
An alignment film paint SE-7492 manufactured by Nissan Chemical Industry is applied thereon by spin coating, and cured at 180 ° C. for 1 hour in a constant temperature bath to form alignment films 303 and 306. Thereafter, rubbing treatment is performed in the direction shown in FIG. 29 using a rubbing cloth made of rayon, and spacer 5 made by Sekisui Fine Chemical Co., Ltd. and Stract Bond 352A (trade name of seal resin made by Mitsui Toatsu Chemicals, Inc.) are used. The liquid crystal cell 309 (hereinafter, referred to as liquid crystal cell A) was formed by laminating the substrates so that the distance between the substrates was 6.5 μm.

At this time, a rubbing treatment was performed so that the liquid crystal pretilt angle at the interface of the alignment film was about 5 degrees.

Next, the liquid crystal MJ96435 (refractive index anisotropy Δn = 0.138) was injected into the liquid crystal cell A by a vacuum injection method to obtain a test cell A.

Next, a polarizing plate was bonded to the test cell A such that the polarization axis thereof was at an angle of 45 degrees with the rubbing direction of the alignment film and the polarization axis directions were orthogonal to each other.
When a transition from the splay alignment to the bend alignment was observed by applying a V rectangular wave, all the electrode regions were changed from the splay alignment to the bend region in about 5 seconds.

In the region where the projection 310 is formed, the thickness of the liquid crystal layer is smaller than that of the surrounding liquid crystal layer region, and the electric field intensity is effectively larger, and the bend transition surely occurs from this portion. The generated bend orientation quickly spreads to other regions.

That is, a reliable and high-speed spray-to-bend transition can be achieved.

It is needless to say that the cross-sectional shape of the protruding object may be trapezoidal, triangular, or semicircular in addition to the rectangular shape as in this embodiment.

[0324] As a comparative example, a splay alignment liquid crystal cell R was prepared by the same process except that a glass substrate with a transparent electrode having no convex portion 310 was used.
6435 was sealed to form a test cell R. When a 7 V rectangular wave is applied to this test cell R, the time required for all the electrode regions to transition from the splay orientation to the bend region is 42
Second, the effect of the present invention is clear.

(Embodiment 14) FIG. 30 shows Embodiment 1 of the present invention.
FIG. 31 is a configuration external view of a liquid crystal cell used in the liquid crystal display device according to No. 4, and FIG. 31 is a plan view thereof. FIG. 30 shows FIG.
It is sectional drawing seen from arrow X1-X1. Embodiment 1
No. 4 is characterized in that the convex object 310 is provided on the transparent electrode 307a formed outside the display pixel area. Hereinafter, the manufacturing procedure will be described.

The glass substrate 30 having the transparent electrode 302
1, and an alignment film paint SE-7492 manufactured by Nissan Chemical Industries, Ltd. is applied by spin coating on a glass substrate 308 on which a convex shape is formed, and is cured at 180 ° C. for 1 hour in a thermostatic oven to obtain alignment films 303, 306, 306a is formed. Thereafter, rubbing treatment is performed in the direction shown in FIG. 29 using a rubbing cloth made of rayon, and spacer 5 made by Sekisui Fine Chemical Co., Ltd. and Stract Bond 352A (trade name of seal resin made by Mitsui Toatsu Chemicals, Inc.) are used. And the substrate spacing is 6.
A liquid crystal cell (liquid crystal cell B)
) Was created.

At this time, a rubbing treatment was performed so that the liquid crystal pretilt angle at the interface of the alignment film was about 5 degrees.

Next, liquid crystal MJ96435 (refractive index anisotropy Δn = 0.138) was injected into liquid crystal cell B by a vacuum injection method.

Next, a polarizing plate was bonded to the liquid crystal cell B such that the polarization axis of the liquid crystal cell B was at an angle of 45 ° with the rubbing direction of the alignment film, and the polarization axes of the liquid crystal cell B were perpendicular to each other.
When a transition from the splay orientation to the bend orientation was observed by applying a rectangular wave, all the electrode regions transitioned from the splay orientation to the bend region in about 7 seconds.

In this embodiment, a convex portion is provided outside the display pixel region to generate a bend transition nucleus outside the display pixel region. The generated bend orientation is from outside the display pixel region to the display pixel region. It was confirmed that it spread quickly within.

There is a region between the display pixel region and the bend nucleus generation electrode region to which no electric field is applied (having no electrode portion). Expands.

(Embodiment 15) FIG. 32 shows Embodiment 1.
FIG. 27 is an external view of a configuration of a liquid crystal cell used in the liquid crystal display device according to No. 5, and FIGS. 27, 28, and 33 are a part of a manufacturing process for explaining the production of a convex-shaped object.

The glass substrate 308 has a P
A C-based resist material is applied to form a resist thin film having a thickness of 1 μm. Next, the resist thin film 320 is irradiated and irradiated with parallel ultraviolet rays 323 through a photomask 321 provided with an opening 322 having a rectangular pattern. The resist thin film 20 exposed to the parallel light is developed and rinsed,
Prebaking is performed at a temperature of ° C. to form a shape 310 having a convex cross section as shown in FIG.

Next, post-baking is performed at 150 ° C. which is equal to or higher than the glass transition point of the resist thin film material, and the shoulder of the convex 310 is gently inclined in the forward direction. It is manufactured in the process of forming in a similar manner.

Next, an ITO electrode was formed in a thickness of 2,000 mm on the substrate according to a standard method, and a glass substrate 30 with an electrode was formed.
And 8. Then, the glass substrate 301 having the transparent electrode 302 and the glass substrate 3 on which the above-mentioned convex object is formed
08, an alignment film paint SE-7492 manufactured by Nissan Chemical Industries, Ltd. is applied by a spin coating method, and cured at 180 ° C. for 1 hour in a thermostat to form alignment films 303 and 306. Thereafter, rubbing treatment was performed in the direction shown in FIG. 29 using a rubbing cloth made of rayon, and spacers 3 made by Sekisui Fine Chemical Co., Ltd. were used.
5 and Structbond 352A (trade name of seal resin manufactured by Mitsui Toatsu Chemicals, Inc.) to obtain a substrate spacing of 6.
A liquid crystal cell 309 (hereinafter, referred to as a liquid crystal cell C) was formed by bonding to each other so that the thickness became 5 μm.

At this time, the rubbing treatment was performed so that the liquid crystal pretilt angle at the interface of the alignment film was about 5 degrees.

Next, the liquid crystal MJ96435 (refractive index anisotropy Δn = 0.138) was injected into the liquid crystal cell C by a vacuum injection method to obtain a test cell C.

Next, a polarizing plate was bonded to the test cell C such that the polarization axis thereof was at an angle of 45 ° with the rubbing direction of the alignment film, and the polarization axis directions were orthogonal to each other.
When a transition from the splay alignment to the bend alignment was observed by applying a V rectangular wave, all the electrode regions were changed from the splay alignment to the bend region in about 7 seconds.

In the test cell C, the electric field is concentrated at the tip of the triangular shape, and bend orientation is generated from this portion. In addition, in the upper part of the triangular object 60, there are a rubbed portion and a rubbed portion by the rubbing process. As a result, a region where the sign of the liquid crystal pretilt angle is opposite is formed. That is, the liquid crystal director is horizontal to the substrate surface in the vicinity of the convex portion, which is also considered to contribute to a high-speed spray-bend transition.

In this embodiment, the electric field concentration portion is provided in the pixel region. However, the same effect can be obtained by providing the electric field concentration portion outside the pixel region. Further, in this embodiment, the electric field concentration portion is disposed only on one side of the substrate, but it is needless to say that the electric field concentration portion may be disposed on both sides of the substrate.

(Embodiment 16) FIG. 34 shows Embodiment 1 of the present invention.
FIG. 35 is a configuration external view of a liquid crystal cell used in a liquid crystal display device according to Embodiment 6, and FIG.
02 represents an electrode pattern.

An alignment film paint S manufactured by Nissan Chemical Industries is formed on two glass substrates 301 and 308 having a transparent electrode 302 having an opening 380 and a transparent electrode 307 having no opening.
E-7492 was applied by spin coating and placed in a thermostat.
After curing at 80 ° C. for 1 hour, alignment films 303 and 306 are formed. Thereafter, a rubbing treatment is performed using a rubbing cloth made of rayon in the direction shown in FIG. 29, and a spacer 305 and a structuring bond 35 made by Sekisui Fine Chemical Co., Ltd.
Using 2A (trade name of seal resin manufactured by Mitsui Toatsu Chemicals, Inc.), the substrates were bonded together so that the distance between the substrates was 6.5 μm, thereby forming a liquid crystal cell 309 (hereinafter referred to as a liquid crystal cell D).

At this time, a rubbing treatment was performed so that the liquid crystal pretilt angle at the interface of the alignment film was about 5 degrees.

Next, a liquid crystal MJ96435 (refractive index anisotropy Δn = 0.138) was injected into the liquid crystal cell D by a vacuum injection method to obtain a test cell D.

Next, a polarizing plate is attached so that the polarization axis forms an angle of 45 degrees with the rubbing direction of the alignment film, and the polarization axis directions are orthogonal to each other. The transition from to the bend orientation was observed.

In this test cell D, a 2 V, 30 Hz, rectangular wave was applied to the electrode on the glass substrate 8 side, and 7 V was applied to the electrode on the glass substrate 1 side.
When a rectangular wave was applied at V, 30 Hz, the time required for all electrode regions to transition from the splay orientation to the bend region was 5 seconds, and an extremely fast bend transition was realized.

In this embodiment, an electric field of 5V (= 7V-2V) is applied to the liquid crystal layer sandwiched between the two electrodes, but 7V (= 7V-0V) is applied to the liquid crystal layer at the electrode opening. Since the effective electric field of (1) is applied, the bend orientation is generated from here.

In this embodiment, the opening is rectangular.
It goes without saying that other shapes such as a circle and a triangle may be used.

(Embodiment 17) FIG. 36 shows Embodiment 1 of the present invention.
FIG. 37 is a cross-sectional view of a principal part of a liquid crystal cell used in the liquid crystal display device according to No. 7, and FIG. 37 is an enlarged view of a part thereof. This liquid crystal cell has a pixel switching element 3 on a glass substrate 308.
80, a signal electrode line 381, and a gate signal line (not shown) are formed. The switching element 380, the signal electrode line 381 and the gate signal line are covered with a planarizing film 382.
Are formed. Then, a display electrode 307 is formed on the flattening film 382, and the display electrode 307 and the switching element 380 are electrically connected via a relay electrode 384 inserted in a contact hole 383 opened in the flattening film 382. It is connected to the. The relay electrode 384 has a concave portion 384a on the upper opening side of the contact hole 383 as shown in FIG. Such a recess 38
With 4a, an opening is formed in the display electrode 307, and it becomes possible to cause concentration of an electric field near the concave portion 384a. Therefore, the transfer time can be shortened.

(Embodiment 18) FIG. 38 shows an embodiment 18.
8 is a configuration external view of the liquid crystal display device according to No. 8. FIG.

Test Cell D Created in Embodiment 16
Phase plates 312, 315, negative uniaxial phase plates 311, 314, positive uniaxial phase plate 319, which are made of an optical medium having a negative refractive index anisotropy in which the main axes are arranged in a hybrid manner.
The polarizing plates 313 and 316 were adhered in the arrangement shown in FIG. 39, and a liquid crystal display device was produced.

At this time, the phase difference plates 312, 315, 31
The retardation values of 1, 314 and 319 are 550 wavelengths.
26 nm, 26 nm, 35
0 nm, 350 nm, and 150 nm.

FIG. 40 shows the voltage-transmittance characteristics at the front of the liquid crystal display device at 25 ° C. After applying a rectangular wave voltage of 10 V for 10 seconds to confirm the bend orientation, measurement was performed while decreasing the voltage. In the present liquid crystal display element, since the transition from the bend alignment to the splay alignment occurs at 2.1 V, it is necessary to perform display with a voltage of 2.2 V or more effectively.

Next, the viewing angle dependence of the contrast ratio when the white level voltage was 2.2 V and the black level voltage was 7.2 V was measured. At least one was achieved, and it was confirmed that sufficient wide viewing angle characteristics were maintained even when a part of the liquid crystal director orientation different from the surroundings was provided on the substrate alignment film surface. In addition, visual observation revealed no defective orientation or defective display quality.

When the response time between 3 V and 5 V was measured, the rise time was 5 ms and the fall time was 6 ms.

As is clear from the above, the liquid crystal display device of the present invention can achieve high-speed splay-bend alignment transition without sacrificing the wide viewing angle characteristics and response characteristics of the conventional OCB mode. Its practical value is extremely large.

(Embodiment 19) FIG. 41 shows Embodiment 19 of the present invention.
9 is a cross-sectional view of a main part of the liquid crystal display device according to No. 9; The liquid crystal cell operated as a bend alignment type cell is a so-called sandwich cell in which a liquid crystal layer 402 is sealed between two parallel substrates 400 and 401. Usually, a transparent electrode is formed on one substrate, and a pixel electrode having a thin film transistor is formed on the other substrate.

FIG. 41A is a schematic diagram showing the orientation in the initial state where no electric field is applied. The alignment in the initial state is a state in which the molecular axes of the liquid crystal molecules are substantially parallel and substantially uniform while having a slight inclination with respect to the planes of the substrates 400 and 401, that is, homogeneous alignment. The liquid crystal molecules existing at the interface with the substrate are both upper and lower substrates 400 and 401.
, Are inclined in opposite directions. That is, the orientation angles θ1 and θ2 of the liquid crystal molecules existing at the interface with the substrate.
(That is, the pretilt angles) are adjusted to have different signs. In the following description, the orientation angle and the pretilt angle are angles in which the inclination of the molecular axis of the liquid crystal molecules with respect to a plane parallel to the substrate is positive counterclockwise with respect to the plane parallel to the substrate.

When an electric field having a strength exceeding a certain value in a direction perpendicular to the plane of the substrate is applied to the liquid crystal layer 402 in the state shown in FIG. 41 (a), the alignment state of the liquid crystal changes, and the state shown in FIG. Transition to the orientation shown.

The orientation shown in FIG. 41B is called a bend orientation. In the vicinity of both substrate surfaces, the inclination of the molecular axis of the liquid crystal molecules with respect to the substrate plane, that is, the absolute value of the orientation angle is small, and the liquid crystal layer 402 The absolute value of the orientation angle of the liquid crystal molecules is large in the central part of the. Further, the liquid crystal layer has substantially no twisted structure over the entire liquid crystal layer.

Observing the transition from the homogeneous alignment to the bend alignment in detail, first, the liquid crystal layer 402
A nucleus of a bend orientation is generated in a part of the liquid crystal layer, and this nucleus grows gradually while eating other regions of the homogeneous orientation, and finally, the entire liquid crystal layer becomes the bend orientation. In other words, transition of the liquid crystal layer to bend alignment requires generation of nuclei, that is, transition from homogeneous alignment to bend alignment in a minute region.

The inventors analyzed the transition to the bend orientation in a minute region by solving the equation of motion of the unit vector of the liquid crystal molecule orientation (hereinafter, referred to as “director”). Conditions that can occur in the system. The method will be described below.

The alignment state of the liquid crystal is described by the director. The director n is a function represented by [Equation 1].

(Equation 1)

The free energy density f of the liquid crystal is given by
Can be expressed as a function of director n.

(Equation 2)

Here, k11, k22 and k33 are Frank's elastic constants, which represent the splay, twist and bend elastic constants, respectively. Δε represents the difference between the dielectric constant of the liquid crystal in the molecular axis direction and the dielectric constant in the direction perpendicular thereto, that is, the dielectric anisotropy. E is an external electric field.

In [Equation 2], the first, second, and third terms
The terms respectively represent the elastic energy due to the spreading, twisting and bending of the liquid crystal. The fourth term represents electric energy due to the electric interaction between the external electric field and the liquid crystal. The electric energy is minimum when n is parallel to E if Δε> 0, and minimum when n is orthogonal to E when Δε <0. Therefore, when an electric field E exceeding a certain intensity is applied, the liquid crystal molecules are oriented so that the molecular long axis is parallel to the direction of the electric field if Δε> 0, and if Δε <0, the liquid crystal molecules are aligned. The axis is oriented so as to be orthogonal to the direction of the electric field.

The total free energy F of the liquid crystal when the initial molecular orientation is deformed by an external electric field can be expressed as a volume integral of f.

(Equation 3) As shown in [Equation 3], the total free energy F is a function (that is, a functional) defined with the unknown function n (x) representing the director as a variable. The alignment state of the liquid crystal that appears under the application of an external electric field is described by n (x) that minimizes the total free energy F under appropriate boundary conditions. That is, if n (x) that minimizes F is determined, the orientation state of the liquid crystal can be predicted. Furthermore, if the director n (x, t) can be determined in consideration of time change such that F is minimized under appropriate boundary conditions,
Any behavior of the device, such as optical constants, can be predicted. This is a typical principle of least action physically, and a mathematically small variational polarization problem with boundary values.

Then, [Equation 3] is solved in principle. However, for example, in an analytical method using the Euler's equation, a complicated nonlinear equation appears, so that it is difficult to easily determine the functional form of the director n (x).

Therefore, in order to easily solve [Equation 3], the following method is adopted. First, the integration space is discretized by a method similar to the finite element method. That is, the entire integration space is divided into np elements, and [Equation 3] is expressed as the sum of the integration of each element.

(Equation 4)

The following approximation is performed on the director n (x) in the partial integration space ΔV. nx
, Ny, and nz are originally functions of x, y, and z as shown in Expression 2, but are assumed to be constant at ΔV. Also, dnx, j / dx = (nx, j + 1−dnx,
j) / Δx. Note that nx, j is nx in the j-th element, and is an unknown value while being constant at ΔV as described above. This partial integration space ΔV
Although the approximation of n (x) in is rough, this can be covered by making the division of the integration space finer, and the approximation can be improved.

According to the above approximation, in [Equation 4], n
Since x, j, ny, j and nz, j are constants in one element,
The integral itself can be easily calculated. However, even at this stage,
The equation representing the total free energy F is still complex, with many unknowns nx, j, ny, j, nz, j higher-order and nonlinear terms proportional to the number of divisions. Where nx, 0, ny, 0,
Values such as nz, 0 can easily be given as boundary conditions.

According to the above approximation, the total free energy F
Is

(Equation 5) It is converted to the form. That is, the total free energy F
Is converted from a functional defined with the unknown function n (x) as a variable to a function of unknowns nx, j, ny, j, nz, j. The unknowns nx, j, ny, j, nz, j are values that minimize the function F in a multidimensional parameter space.

As described above, the bend alignment of the liquid crystal has a structure having substantially no twist. Director n
Is originally a function of x, y, z as described above,
It can be expressed as a function of the orientation angle. in this case,
The director n in the bend orientation is:

(Equation 6) It is represented by Here, θ is the inclination of the liquid crystal molecules with respect to a plane parallel to the substrate, that is, the orientation angle. Θ depends only on the distance z of the liquid crystal molecules from the substrate.
FIG. 2 is a schematic diagram showing this director.

[Equation 6] is substituted into [Equation 4], divided into np elements and discretized, and θj that minimizes F is obtained for each element. That is, for each element,

(Equation 7) Θj that satisfies the following equation is obtained. Note that d is L / n
p and L is the distance between the substrates.

However, it is not easy to simultaneously solve np complex nonlinear equations such as [Equation 7]. Then, by performing the following circuit analogy, [Equation 7]
Solve. The director's equation of motion is

(Equation 8) It is represented by Here, η is the viscosity of the liquid crystal. [Equation 8]
, The following circuit analogy is performed.

(Equation 9) [Equation 8] is

(Equation 10) Is converted to The circuit corresponding to [Equation 10] is composed of np CR circuits as shown in FIG. [Equation 1
0] represents the current flowing through the CR circuit. In addition,
Rj is a resistor for relaxing discharge, and is a voltage control resistor that defines the current (i) flowing through the CR circuit as i = ∂F (Vj) / ∂Vj.

The current i (= ΔF / ΔVj) converges to zero at a specific Vj. That is, Vj can be automatically obtained by obtaining the voltage at which the current flowing through the CR circuit becomes zero in the circuit simulator.

As described above, by replacing the director's equation of motion with an equivalent circuit, a nonlinear simultaneous equation expressing the liquid crystal alignment phenomenon is analyzed on a circuit simulator, and the external electric field E and the alignment state (orientation angle θj) are determined. Relationship can be determined.

In the above method, the nonlinear simultaneous equations expressing the orientation phenomenon are replaced with circuits by analogy of an electric circuit and analyzed on a circuit simulator. Therefore, only an equivalent circuit is set in a program. It does not include the computational process to solve the equation itself. Therefore, simplification and reduction of the program can be realized.

Further, when the change of the orientation angle θj with the increase of the external electric field E is calculated based on the above method, the critical electric field Ec of the liquid crystal transition is obtained as the external electric field E when the orientation angle θj changes suddenly. be able to.

FIG. 44 shows an example of a calculation result based on the above method, and shows a time change of θj when the external electric field E is increased with time. The results in FIG. 4 are based on the assumption that the boundary conditions are fixed as θ0 = + 0.1 rad, θnp−1 = −0.1 rad, k11 = 6 × 10 ⁻⁷ dyn, k33 = 12 × 10 ⁻⁷ dy
n, Δε = 10. As shown in FIG. 4, at the initial stage of the application of the electric field, the orientation angles θj are all relatively small, indicating that the orientation state of the liquid crystal is homogeneous. However, after a certain period of time, that is, when the external electric field E exceeds a certain value (E> Ec), the orientation angle θ
j changes suddenly and metastasis occurs. The orientation angle θj after the transition is
The absolute value increases from the vicinity of both substrates toward the center of the liquid crystal layer, and it can be seen that the alignment state of the liquid crystal after transition is bend alignment.

As the critical electric field Ec is smaller, the alignment state of the liquid crystal can be rapidly changed from the homogeneous alignment to the bend alignment. Then, based on the above method, the conditions for determining the orientation of the liquid crystal were variously changed, and the critical electric field Ec under each condition was calculated. As a result, the critical electric field Ec becomes
In particular, it has been found that the liquid crystal is affected by the elastic constant (spray elastic constant) of the liquid crystal and the asymmetry of the pretilt angle.

FIG. 45 shows the result of obtaining the relationship between the splay elastic constant k11 and the critical electric field Ec. Note that FIG. 45 shows that the boundary conditions are θ0 = + 0.1 rad, θnp−1 =
−0.1 rad, k33 = 12 × 10 ⁻⁷ dyn, Δε = 10
It is the result calculated as. As shown in FIG. 45, as the splay elastic constant k11 increases, the critical electric field Ec increases. In particular, in the range of k11> 10 × 10 ⁻⁷ dyn, Ec sharply increases as k11 increases.

Therefore, in order to realize a quick liquid crystal transition, it is effective to make the splay elastic constant k11 less than 10 × 10 ⁻⁷ dyn, preferably 8 × 10 ⁻⁷ dyn or less. The lower limit of the splay elastic constant k11 is not particularly limited, but is preferably 6 × 10 ⁻⁷ dyn or more. This is because it is usually difficult to synthesize or prepare a liquid crystal material having k11 <6 × 10 ⁻⁷ dyn.

The liquid crystal material having the above splay elastic constant k11 is not particularly limited, but examples thereof include a pyrimidine-based liquid crystal, a dioxane-based liquid crystal, and a biphenyl-based liquid crystal.

The asymmetry of the pretilt angle can be expressed by the difference (Δθ) between the absolute values of the pretilt angles between the upper and lower substrates. Further, as described above, the pretilt angles θ0 and θn
Since p-1 has opposite signs, the difference (Δθ) between the absolute values of the pretilt angles can be represented by Δθ = | θ0 + θnp-1 |.

FIG. 46 (a) shows the result of determining the relationship between the difference (Δθ) between the absolute values of the pretilt angles between the upper and lower substrates and the critical electric field Ec. FIG. 6a shows that k11 = 6 × 1
^{0 -7 dyn, k33 = 12 ×} 10 -7 dyn, the result of calculation as [Delta] [epsilon] = 10. As shown in FIG. 46A, the larger the pretilt angle difference Δθ is, the lower the critical electric field Ec is. In particular, in the range of Δθ ≧ 0.0002 rad, Ec sharply decreases as Δθ increases.

Therefore, in order to realize a rapid liquid crystal transition, it is effective to set the difference Δθ between the pretilt angles to at least 0.0002 rad, preferably at least 0.035 rad. Also, regarding the upper limit of the pretilt angle difference Δθ,
Although not particularly limited, it is usually less than 1.57 rad, preferably 0.785 rad or less.

Note that the pretilt angles θ0 and θnp-1 are
The absolute value is usually adjusted so as to be more than 0 rad and less than 1.57 rad, preferably from 0.017 rad to 0.785 rad. The adjustment of the pretilt angle can be controlled by forming an appropriate liquid crystal alignment film on the substrate surface by a method such as an oblique deposition method and a Langmuir-Blodgett (LB) method. The liquid crystal alignment film is not particularly limited, for example, polyimide resin, polyvinyl alcohol, polystyrene resin,
Examples thereof include polycinnamate resin, chalcone resin, polypeptide resin, and polymer liquid crystal. In addition to selecting the material for the liquid crystal alignment film, adjusting the inclination of the evaporation direction with respect to the substrate surface when using the oblique evaporation method, and adjusting the conditions such as the substrate pulling speed when using the LB method. Thus, the pretilt angle can be controlled.

The critical electric field Ec is affected by the non-uniformity of the electric field in the liquid crystal layer. This is because the distortion of the electric field generated in the liquid crystal layer affects the stability of the alignment state of the liquid crystal molecules. The non-uniformity of the electric field is determined by the main electric field E0 applied substantially uniformly to the liquid crystal layer and the sub-electric field E1 applied non-uniformly.
(E1 / E0). E1
Is the maximum value of the applied sub-electric field.

The relationship between the nonuniformity E1 / E0 of the electric field and the critical electric field Ec can be examined as follows based on the above-mentioned method. That is, an external electric field E is applied to the liquid crystal layer.
While applying a main electric field E0 which is a uniform electric field,
The change of the orientation angle θj with the increase of the main electric field E0 is calculated under the condition that the sub-electric field E1 which is an inhomogeneous electric field is superimposed and applied. At this time, the auxiliary electric field E1 is increased so that E1 / E0 becomes constant at a predetermined value as the main electric field E0 increases. From the obtained calculation result, the critical electric field Ec of the liquid crystal transition is obtained as the main electric field E0 when the orientation angle θj suddenly changes.

FIG. 47 is a graph showing the relationship between E1 / E0 based on the above method.
Is an example of a calculation result obtained by calculating the critical electric field Ec under various conditions by changing the value of. Note that the results in FIG. 7 indicate that the boundary conditions are θ0 = + 0.26 rad and θnp−1 = −0.25 rad.
K11 = 6 × 10 ⁻⁷ dyn, k33 = 12 × 1
It is a result calculated assuming that 0 ^-7 dyn and Δε = 10. FIG.
As shown in FIG. 7, as E1 / E0 increases, that is, as the electric field becomes more non-uniform, the critical electric field Ec increases, and E1 increases.
In the vicinity of / E0 = 1, Ec becomes infinitesimal. This is considered to be because when the electric field of the liquid crystal layer has a distortion, the homogeneous alignment becomes unstable as compared with the case where the electric field is uniform, and as a result, the transition to the bend alignment is rapidly developed.

Therefore, in order to realize a rapid liquid crystal transition, a substantially uniform main electric field E0 is applied to the liquid crystal layer.
It is effective to apply a spatially non-uniform electric field E1. In particular, it is effective to set 0.01 <E1 / E0 <1. In the range of E1 / E0 ≦ 0.01, it is difficult to sufficiently obtain the effect of promoting the liquid crystal transition by applying a non-uniform electric field, and in the range of E1 / E0 ≧ 1, the applied voltage becomes too large, so that the actual voltage becomes too large. This is because there is a problem that it is not suitable for use. Further, it is preferable that 0.5 ≦ E1 / E0 ≦ 1.

The non-uniform electric field E1 can be applied to the liquid crystal layer in a direction perpendicular to the substrate by using a voltage applied between the source electrode (or gate electrode) of the thin film transistor and the transparent electrode. . The non-uniform electric field E1 is preferably an AC electric field having a frequency of 100 kHz or less, and more preferably, the amplitude is attenuated over time.

The splay elastic constant (k 11) and the pretilt angle asymmetry (Δ
θ) and electric field non-uniformity (E1 / E0), it is preferable to satisfy two or three conditions in combination. This is because by combining these conditions, the critical electric field Ec can be reduced more reliably than when only one of the conditions is satisfied.

For example, FIG. 46 (b) shows a result calculated under the same conditions as in FIG. 46 (a) except that a non-uniform electric field E1 is applied together with a substantially uniform external electric field E0.
FIG. 46B shows the result when E1 / E0 = 0.03. As can be seen from the comparison between FIGS. 46A and 46B, the critical electric field Ec is further reduced by satisfying the two conditions of the asymmetry of the pretilt angle and the non-uniformity of the electric field, and the liquid crystal is more rapidly increased. Metastasis can be realized.

[0396]

As described above, according to the present invention, a method for driving a liquid crystal display device using an OCB cell includes the steps of:
A step of applying an AC voltage on which a bias voltage is superimposed and continuously applying the AC voltage or a step of applying an AC voltage on which a bias voltage is superimposed and a step of applying an open state or a low voltage to a pair of substrates are alternately performed. The transition from the splay alignment to the bend alignment can be completed almost surely and in a very short time, and the bend alignment type OCB which has no display defects, has a high response speed, is suitable for moving image display, and has a wide field of view. A liquid crystal display device can be obtained.

Further, according to the present invention, the OCB display mode of high-speed response, wide visual field and high image quality which is composed of an active matrix type liquid crystal cell free from display defects, which can easily and quickly transition from the splay alignment to the bend alignment is realized. The effect that a liquid crystal display device can be obtained is obtained.

According to the present invention, a splay-aligned liquid crystal cell in which the pretilt angles of the liquid crystal at the upper and lower interfaces of the liquid crystal layer between the array substrate and the opposing substrate are opposite to each other, and are aligned in parallel with each other, Sometimes it is in splay orientation,
Prior to driving the liquid crystal display, an initialization process for changing from splay alignment to bend alignment by applying a voltage is performed. In an active matrix type liquid crystal display device that performs liquid crystal display driving in the initialized bend alignment state, one pixel is driven. And at least one horizontal electric field applying unit for transition excitation, generating a horizontal electric field by the horizontal electric field applying unit, and applying a voltage between the pixel electrode and the common electrode continuously or intermittently. Each time a transition nucleus is generated and the entire pixel is transitioned from the splay alignment to the bend alignment, the transition from the splay alignment to the bend alignment occurs quickly and reliably.
As a result, it is possible to provide a liquid crystal display device in the OCB display mode which has no display defects, has a high response speed, and has a wide field of view and high image quality.

According to the present invention, an OCB display mode alignment liquid crystal display device comprises a parallel alignment liquid crystal including a liquid crystal layer sandwiched between a pair of substrates and a phase compensator disposed outside the substrates. It is a display element that can achieve reliable and high-speed splay-bend alignment transition, and its practical value is extremely large.

Further, according to the present invention, there is provided a method for applying an electric field to a liquid crystal held between a first substrate and a second substrate facing each other to change the orientation of the liquid crystal to a bend orientation. Thus, the splay elastic constant k11 of the liquid crystal is 10 ×
10 ⁻⁷ dyn ≧ k11 ≧ 6 × 10 ⁻⁷ dyn, the absolute value of the pretilt angle of the liquid crystal with respect to the first substrate is θ1, and the absolute value of the pretilt angle of the liquid crystal with respect to the second substrate is θ1. When the value is θ2, 1.57ra
Since the relationship d> | θ1−θ2 | ≧ 0.0002 rad is satisfied, the liquid crystal can be rapidly transferred to the bend alignment.

Further, according to the present invention, there is provided a method for applying an electric field to a liquid crystal held between a first substrate and a second substrate facing each other to change the orientation of the liquid crystal to a bend orientation. Thus, the splay elastic constant k11 of the liquid crystal is 10 ×
The range of 10 ⁻⁷ dyn ≧ k11 ≧ 6 × 10 ⁻⁷ dyn, and the electric field is applied to a main electric field that is applied spatially uniformly,
An electric field obtained by superimposing a sub electric field applied in a spatially non-uniform manner, wherein the main electric field is E0, and the maximum value of the sub electric field is E1.
In this case, the relationship of 1.0> E1 / E0> 1/100 is satisfied, so that the liquid crystal can be rapidly transferred to the bend alignment.

Further, according to the present invention, there is provided a method for applying an electric field to a liquid crystal held between a first substrate and a second substrate opposed to each other to change the orientation of the liquid crystal to bend orientation. When the absolute value of the pretilt angle of the liquid crystal with respect to the first substrate is θ1, and the absolute value of the pretilt angle of the liquid crystal with respect to the second substrate is θ2, 1.5
7 rad> | θ 1 −θ 2 | ≧ 0.0002 rad, and the electric field is obtained by superimposing a spatially non-uniformly applied auxiliary electric field on a spatially uniformly applied main electric field. When the main electric field is E0 and the maximum value of the sub electric field is E1, 1.0> E1 / E0> 1/1
00, the liquid crystal can be quickly transferred to the bend alignment.

Further, according to the present invention, the third
An electric field is applied to the liquid crystal held between the first substrate and the second substrate.
Method of applying and changing the orientation of the liquid crystal to bend orientation
Wherein the splay elastic constant k11 of the liquid crystal is 10 × 1
0^-7dyn ≧ k11 ≧ 6 × 10 ^-7dyn range,
The absolute value of the pretilt angle of the liquid crystal with respect to the first substrate is
θ1, and the pretilt of the liquid crystal with respect to the second substrate
When the absolute value of the angle is θ2, 1.57 rad> | θ1
-Θ2 | ≧ 0.0002 rad, and
First, the electric field is applied to a main electric field that is applied spatially uniformly,
An electric field superimposed on a spatially non-uniformly applied sub-electric field
The main electric field is E0, and the maximum value of the sub electric field is E1.
And the relationship 1.0> E1 / E0> 1/100
The liquid crystal must be quickly transitioned to bend alignment to satisfy
Can be.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a part of a liquid crystal display device including a bend alignment type OCB cell.

FIG. 2 is a cross-sectional view of a liquid crystal cell illustrating a state of transition from splay alignment to bend alignment.

FIG. 3 is a conceptual diagram of a pixel unit by a driving method of the liquid crystal display device according to the first embodiment of the present invention.

FIG. 4 is a voltage waveform diagram for orientation transition used in the first embodiment of the present invention.

FIG. 5 is a diagram illustrating a relationship between a bias voltage and a transition time according to the first embodiment of the present invention.

FIG. 6 is a conceptual diagram of a pixel unit by a driving method of a liquid crystal display device according to a second embodiment of the present invention.

FIG. 7 is a voltage waveform diagram for orientation transition used in Embodiment 2 of the present invention.

FIG. 8 is a diagram illustrating a relationship between a bias voltage and a transition time according to the second embodiment of the present invention.

FIG. 9 is a conceptual diagram of a pixel unit based on a driving method of a liquid crystal display device according to a third embodiment of the present invention.

FIG. 10 is a voltage waveform diagram for orientation transition used in Embodiment 3 of the present invention.

FIG. 11 is a diagram illustrating a relationship between a bias voltage and a transition time according to a third embodiment of the present invention.

FIG. 12 is a conceptual diagram of a pixel unit by a driving method of a liquid crystal display device according to a fourth embodiment of the present invention.

FIG. 13 is a normal drive voltage waveform diagram of the liquid crystal display device according to Embodiment 4 of the present invention.

FIG. 14 is a voltage waveform diagram for orientation transition used in Embodiment 4 of the present invention.

FIG. 15 is a voltage waveform diagram for orientation transition used in Embodiment 5 of the present invention.

FIG. 16 is a schematic sectional view of a liquid crystal display device according to a seventh embodiment of the present invention.

FIG. 17 is a schematic plan view of a liquid crystal display device according to Embodiment 7 of the present invention.

FIG. 18 is a diagram illustrating the method of manufacturing the liquid crystal display device according to the seventh embodiment of the present invention.

19A and 19B are diagrams showing a liquid crystal display device according to an eighth embodiment of the present invention. FIG. 19A is a schematic sectional view of the liquid crystal display device, and FIG. 19B is a schematic plan view of the liquid crystal display device. is there.

20A and 20B are diagrams conceptually showing a configuration of a liquid crystal display device according to a ninth embodiment of the present invention, wherein FIG. 20A is a schematic plan view of the liquid crystal display device, and FIG. It is a schematic sectional drawing of an apparatus.

FIG. 21 is a diagram conceptually showing a configuration of a liquid crystal display device according to Embodiment 9 of the present invention.

FIG. 22 is a diagram showing another example of the liquid crystal display device according to Embodiment 9 of the present invention.

23A and 23B are diagrams conceptually showing a configuration of a liquid crystal display device according to a tenth embodiment of the present invention. FIG. 23A is a schematic plan view of the liquid crystal display device, and FIG. FIG. 23C is a schematic sectional view of a liquid crystal display device of another example, and FIG. 23D is a schematic sectional view of a liquid crystal display device of another example.

24A and 24B are diagrams conceptually showing a configuration of a liquid crystal display device according to Embodiment 11 of the present invention. FIG. 24A is a schematic plan view of the liquid crystal display device, and FIG. It is a schematic diagram showing distortion.

25A and 25B are diagrams conceptually showing a configuration of a liquid crystal display device according to a twelfth embodiment of the present invention. FIG. 25A is a schematic sectional view of the liquid crystal display device, and FIG. FIG.

FIG. 26 is a diagram conceptually showing a cross-sectional configuration of a liquid crystal display device according to Embodiment 13 of the present invention.

FIG. 27 is a first embodiment of a liquid crystal display device according to the present invention.
It is a figure for explaining the manufacturing process of the convex-shaped thing formed on glass substrates 3 and 14.

FIG. 28 is a diagram for explaining the manufacturing process for the convex-shaped object following FIG. 27 according to the present invention.

FIG. 29 is a diagram illustrating a rubbing direction of a substrate used in Embodiment 13 of the present invention.

FIG. 30 is a configuration external view of a fourteenth embodiment according to the present invention.

FIG. 31 is a plan view of a fourteenth embodiment according to the present invention.

FIG. 32 is a configuration external view of a liquid crystal cell provided in a liquid crystal display device according to Embodiment 15 of the present invention.

FIG. 33 is a view illustrating a manufacturing process of the convex-shaped object of the liquid crystal cell according to Embodiment 15 of the present invention.

FIG. 34 is a diagram conceptually showing a sectional configuration of a liquid crystal cell provided in a liquid crystal display device according to Embodiment 16 of the present invention.

FIG. 35 is a diagram conceptually showing a pattern of a transparent electrode used in a liquid crystal cell according to Embodiment 16 of the present invention.

FIG. 36 is a fragmentary cross-sectional view of a liquid crystal cell provided in the liquid crystal display device according to Embodiment 17 of the present invention.

FIG. 37 is an enlarged view of a part of FIG. 36;

FIG. 38 is a fragmentary cross-sectional view of a liquid crystal cell provided in the liquid crystal display device according to Embodiment 18 of the present invention.

FIG. 39 is a view illustrating an arrangement of optical elements in a liquid crystal cell provided in a liquid crystal display device according to Embodiment 18 of the present invention.

FIG. 40 is a diagram showing voltage-transmittance characteristics of a liquid crystal cell provided in a liquid crystal display device according to Embodiment 18 of the present invention.

41 (a) is a schematic diagram showing a modular orientation, and FIG. 41 (b) is a schematic diagram (b) showing a bend orientation.

FIG. 42 is a diagram showing a director of a liquid crystal layer.

FIG. 43 is a diagram showing a CR equivalent circuit.

FIG. 44 is a diagram showing a temporal change in the orientation angle (θj) of the liquid crystal under an external electric field which increases with time.

FIG. 45: Spray elastic constant (k11) and critical electric field (E
It is a figure which shows the relationship with c).

FIG. 46 is a diagram illustrating a relationship between a difference (Δθ) between absolute values of pretilt angles and a critical electric field (Ec).

FIG. 47: Electric field inhomogeneity (E1 / E0) and critical electric field (E
It is a figure which shows the relationship with c).

FIG. 48 is a sectional view of a conventional example.

[Explanation of symbols]

20, 21 Substrate 22, 23 Electrode 24, 25 Alignment film 26 Liquid crystal layer 30, 40, 50, 71, 72 Alignment transition drive circuit 31 Liquid crystal display drive circuit 101/102 Polarizer 103 Phase compensator 104 Liquid crystal cell 105 Counter substrate 106 Array substrate 107 Common electrode 108 Pixel electrode 109/110 Alignment film 111 Switching element 112 Liquid crystal layer 113 Signal electrode line 114/114 'Gate electrode line 120 b-Splay alignment 121 t-Splay alignment 123 Disclination line 124 Bend alignment A2 B2, C2, D2 Pretilt angle 201a Array substrate 201b Opposite substrate 202a Pixel electrode 221a Concave portion of pixel electrode 222a Convex portion of pixel electrode 223a Non-fit type convex portion of pixel electrode 224a Non-fit type convex portion of pixel electrode 202b Common Electrode 203a Alignment film 203am Alignment film 203ah Alignment film 203b Alignment film 203bm Alignment film 203bh Alignment film 204a Polarizer 204b Polarizer 205 Phase compensator 206 Signal electrode line 261 Projection of signal electrode line 262 Depression of signal electrode line 263 Non-signal electrode line Fitting type convex portion 207 Gate electrode line 271 Gate electrode line convex portion 272 Gate electrode line concave portion 273 Non-fitting type convex portion of gate electrode line 208 Switching transistor (element) 209 Horizontal electric field application line 291 For horizontal electric field application Line convex portion 209a Horizontal electric field applying line 291a Horizontal electric field applying line 210 Liquid crystal layer 298 Liquid crystal layer 299 Liquid crystal layer 211 Liquid crystal molecule 212 Transparent insulating film 225 Electrode defect portion 226 Disclination line 227b B-spray orientation 227t t-spray orientation 301,308 g Substrates 302, 307 Transparent electrodes 303, 306 Alignment film 304 Liquid crystal layer 304a Liquid crystal alignment when no voltage is applied (spray alignment) 304b Liquid crystal alignment when voltage is applied (bend alignment) 305 Spacer 309 Test cell 310 Convex objects 311, 314 Negative uniaxial film phase plate 312, 315 Phase difference plate made of optical medium having negative refractive index anisotropy in which main axes are hybridly arranged 313, 316 Polarizer 317, 318 Phase compensator 319 Positive uniaxial film phase plate 320 Resist thin film 321 Photo mask 322 Photo mask opening 323 Parallel ultraviolet ray 360 Triangular object 380 Electrode opening

 ──────────────────────────────────────────────────続 き Continuation of the front page (31) Priority claim number Japanese Patent Application No. 11-157060 (32) Priority date June 3, 1999 (June 6, 1999) (33) Priority claim country Japan (JP) (31) Priority claim number Japanese Patent Application No. 11-200102 (32) Priority date July 14, 1999 (July 14, 1999) (33) Priority claim country Japan (JP) (72) Inventor Hiroshi Kubota 1006 Kadoma Kadoma, Kadoma City, Osaka Matsushita Electric Industrial Co., Ltd. (72) Inventor Shinichiro Hatta 1006 Kadoma Kadoma, Kadoma City, Osaka Pref. Matsushita Electric Industrial Co., Ltd. 8 5C006 AA01 BB12 BB15 FA14 FA21 FA55 5C080 AA10 BB05 DD03 DD08 JJ02 JJ05 JJ06

Claims (54)

[Claims] 1. A liquid crystal display device comprising: a pair of substrates; and a liquid crystal layer sandwiched between the substrates. Prior to driving the liquid crystal display, an initialization process is performed to change the orientation state of the liquid crystal layer from the splay orientation to the bend orientation by applying a voltage between the substrates, and the initialized bend orientation state is initialized. In the driving method for performing the alignment transition from the splay alignment to the bend alignment in the liquid crystal display device performing the liquid crystal display driving by using, an AC voltage on which a bias voltage is superimposed is applied between the substrates to transfer the liquid crystal layer to the bend alignment. A method for driving a liquid crystal display device, comprising: 2. A liquid crystal display comprising: a pair of substrates; and a liquid crystal layer sandwiched between the substrates. When no voltage is applied, the liquid crystal layer has a liquid crystal at the upper and lower interfaces, the pretilt angles of which are opposite to each other, and the liquid crystal layers are aligned in parallel with each other. Prior to driving the liquid crystal display, an initialization process is performed to change the orientation state of the liquid crystal layer from the splay orientation to the bend orientation by applying a voltage between the substrates, and the initialized bend orientation state is initialized. A driving method for causing the liquid crystal display device to perform liquid crystal display driving by performing an alignment transition from the splay alignment to the bend alignment, comprising: applying an AC voltage superimposed with the bias voltage between the substrates; and electrically connecting the substrates. And a step of alternately repeating the step of bringing the liquid crystal layer into the open state, thereby causing the liquid crystal layer to transition to the bend alignment. 3. A liquid crystal display comprising: a pair of substrates; and a liquid crystal layer sandwiched between the substrates. When no voltage is applied, the liquid crystal layer has a pre-tilt angle of liquid crystal at the upper and lower interfaces which is opposite to that of the liquid crystal. Prior to driving the liquid crystal display, an initialization process is performed to change the orientation state of the liquid crystal layer from the splay orientation to the bend orientation by applying a voltage between the substrates, and the initialized bend orientation state is initialized. In the liquid crystal display device for performing liquid crystal display driving, a driving method for performing an alignment transition from the splay alignment to the bend alignment, comprising: applying an AC voltage superimposed with a bias voltage between the substrates; A method for driving a liquid crystal display device, wherein a step of applying a low voltage is alternately and repeatedly performed to transfer a liquid crystal layer to bend alignment. 4. The method according to claim 2, wherein a DC voltage is used instead of the AC voltage on which the bias voltage is superimposed. 5. The frequency of the alternating voltage is 0.
The duty ratio of the alternating voltage ranges from 1 Hz to 100 Hz and is at least 1: 1 to 10
3. The method for driving a liquid crystal display device according to claim 2, wherein the ratio is in the range of 00: 1. 6. The frequency of the alternating voltage is 0.
4. The method according to claim 3, wherein a duty ratio of the alternating voltage ranges from 1 Hz to 100 Hz and a duty ratio of the alternating voltage ranges from 1: 1 to 1000: 1. 7. The method of driving an active matrix type liquid crystal display device, wherein the AC voltage is applied to a pixel electrode of the active matrix type liquid crystal display device connected to a switching element formed on one substrate and the other. 2. The method according to claim 1, wherein the voltage is applied to a common electrode formed on the substrate. 8. A method for driving an active matrix type liquid crystal display device, wherein the alternating voltage is applied to a pixel electrode of the active matrix type liquid crystal display device connected to a switching element formed on one substrate and the other. 7. The method according to claim 2, wherein the voltage is applied between a common electrode formed on the substrate and the common electrode. 9. The method according to claim 8, wherein the AC voltage is applied to a common electrode. 10. A method of driving an active matrix type liquid crystal display device, wherein the DC voltage is applied to a pixel electrode of the active matrix type liquid crystal display device connected to a switching element formed on one substrate, and to the other side. 5. The method according to claim 4, wherein the voltage is applied between the common electrode formed on the substrate and the common electrode. 11. The method according to claim 10, wherein the DC voltage is applied to a common electrode. 12. The voltage value of the AC voltage is set to a critical voltage value which is a minimum voltage value required for causing a liquid crystal layer to transition from a splay alignment state to a bend alignment state. 10. The method for driving a liquid crystal display device according to any one of 1, 2, 3, 5, 6, 7, 8, and 9. 13. The voltage value of the DC voltage is set to a critical voltage value which is a minimum voltage value required for causing a liquid crystal layer to transition from a splay alignment state to a bend alignment state. 12. The method for driving a liquid crystal display device according to any one of 4, 10 and 11. 14. The method of driving a liquid crystal display device according to claim 1, wherein the voltage is a voltage that is converted into an alternating current over time. 15. A sprayer comprising: a pair of substrates; and a liquid crystal layer sandwiched between the substrates. When no voltage is applied, the liquid crystal layer has a pre-tilt angle of liquid crystal at the upper and lower interfaces which is opposite to the pre-tilt angle, and is subjected to an alignment treatment in parallel with each other. Prior to driving the liquid crystal display, an initialization process is performed to change the orientation state of the liquid crystal layer from the splay orientation to the bend orientation by applying a voltage between the substrates, and the initialized bend orientation state is initialized. A liquid crystal display device that performs liquid crystal display driving, comprising a voltage applying unit that applies an AC voltage or a DC voltage with a bias voltage superimposed between the substrates in order to cause the liquid crystal layer to transition from the splay alignment to the bend alignment. Liquid crystal display device. 16. The voltage value of the AC voltage or the DC voltage is set to a critical voltage value which is a minimum voltage value required for causing a liquid crystal layer to transition from a splay alignment state to a bend alignment state. The liquid crystal display device according to claim 15, wherein 17. A splay-aligned liquid crystal cell in which liquid crystal pre-tilt angles at liquid crystal layer upper and lower interfaces disposed between an array substrate having pixel electrodes and a counter substrate having a common electrode have opposite pretilt angles and are aligned in parallel to each other. When no voltage is applied, the liquid crystal display is in a splay alignment. Prior to driving the liquid crystal display, an initialization process is performed to change from the splay alignment to the bend alignment by applying a voltage, and the liquid crystal display is driven in the initialized bend alignment state. In the active matrix type liquid crystal display device, the pretilt angle of the liquid crystal in the alignment film formed on the inner surface side of the array substrate indicates the first pretilt angle,
A first liquid crystal cell region in which the pretilt angle of the liquid crystal in the alignment film formed on the inner surface side of the opposing substrate has a second pretilt angle larger than the first pretilt angle; and a first liquid crystal cell region. The pretilt angle of the liquid crystal in the alignment film formed adjacent to the inner surface of the array substrate indicates a third pretilt angle, and the pretilt angle of the liquid crystal in the alignment film formed on the inner surface of the opposing opposing substrate And a second liquid crystal cell region exhibiting a fourth pretilt angle smaller than the third pretilt angle, at least in the same pixel, and the alignment film is disposed between the first liquid crystal cell region and the second liquid crystal cell region. A first voltage for forming a disclination line is applied between the liquid crystal cell that is oriented toward the liquid crystal cell region and the pixel electrode and the common electrode; First voltage applying means for forming a disclination line near a boundary between a cell region and the second liquid crystal cell region; and a first voltage applying device which is higher than the first voltage between the pixel electrode and the common electrode. 2. A liquid crystal display device comprising: a second voltage applying means for generating a transition nucleus in a disclination line by applying a voltage of 2 and causing a transition from a splay alignment to a bend alignment. 18. The liquid crystal display device according to claim 17, wherein said first and fourth pretilt angles are not more than 3 degrees, and said second and third pretilt angles are not less than 4 degrees. 19. The orientation direction of the orientation film is
18. The liquid crystal display device according to claim 17, wherein the liquid crystal display device is perpendicular to a signal electrode line or a gate electrode line along the pixel electrode. 20. The orientation direction of the orientation film is
The liquid crystal display device according to claim 17, wherein the liquid crystal display device is slightly displaced from a direction perpendicular to a signal electrode line or a gate electrode line along the pixel electrode. 21. The second voltage having a frequency of 0.5.
18. The pulse-like voltage according to claim 17, wherein the voltage ranges from 1 Hz to 100 Hz and the duty ratio of the second voltage ranges from 1: 1 to 1000: 1.
The liquid crystal display device as described in the above. 22. The liquid crystal display device according to claim 17, wherein the gate electrode line is in a high state at least during most of the transition period. 23. A part of at least one of the alignment films formed on the inner surface side of the pixel electrode and the common electrode is irradiated with ultraviolet rays to reduce the pretilt angle of the liquid crystal in the alignment film. 22. The liquid crystal display device according to claim 17, further comprising a liquid crystal cell which is divided and divided by changing. 24. A region of at least one of the pixel electrode and the common electrode is planarized by irradiating ultraviolet rays to an area of the pixel electrode and the common electrode in an ozone atmosphere. 22. The liquid crystal cell according to claim 17, wherein an alignment film is coated and baked on the pixel electrode and the common electrode to change the pretilt angle of the liquid crystal in the alignment film. The liquid crystal display device according to any one of the above. 25. A splay-aligned liquid crystal cell in which the liquid crystal pre-tilt angles at the upper and lower interfaces of a liquid crystal layer disposed between an array substrate having pixel electrodes and a counter substrate having a common electrode have opposite pretilt angles and are aligned in parallel to each other. When no voltage is applied, the liquid crystal display is in a splay alignment. Prior to driving the liquid crystal display, an initialization process is performed to change from the splay alignment to the bend alignment by applying a voltage, and the liquid crystal display is driven in the initialized bend alignment state. In the method of manufacturing an active matrix type liquid crystal display device, the pretilt angles of the liquid crystal at the upper and lower interfaces of the liquid crystal layer disposed between the array substrate having the pixel electrodes and the opposing substrate having the common electrode are opposite to each other and parallel to each other. A preparing step of preparing a liquid crystal cell having a splay alignment that has been subjected to an alignment treatment; and disclination between the pixel electrode and the common electrode. Applying a first voltage for forming a line to form a disclination line near a boundary between the first liquid crystal cell region and the second liquid crystal cell region; A second voltage higher than the first voltage is applied between the first liquid crystal cell and the common electrode to generate a transition nucleus at a disclination line near a boundary between the first liquid crystal cell region and the second liquid crystal cell region. And a step of causing a transition from the splay alignment to the bend alignment. 26. The preparatory step, wherein an alignment process is performed such that the pretilt angle of the liquid crystal on the pixel electrode side is smaller than the pretilt angle of the liquid crystal on the common electrode side in a partial region of one pixel. By performing the b-spray alignment of the liquid crystal molecules and performing an alignment process in the other region of the one pixel such that the pretilt angle of the liquid crystal on the pixel electrode side is larger than the pretilt angle of the liquid crystal on the common electrode side. 3. The method according to claim 2, further comprising an alignment process for aligning the liquid crystal molecules in a t-spray.
6. The method for manufacturing a liquid crystal display device according to item 5. 27. The alignment treatment step, wherein a partial region of an alignment film formed on an inner surface side of at least one of the pixel electrode and the common electrode is irradiated with ultraviolet light to reduce a pretilt angle of the liquid crystal. 27. The method for manufacturing a liquid crystal display device according to claim 26, wherein the alignment is divided and changed. 28. The alignment treatment step, wherein at least one of the pixel electrode and the common electrode is irradiated with ultraviolet light in an ozone atmosphere in a partial area of the pixel electrode and the common electrode. After flattening the surface of
27. The method for manufacturing a liquid crystal display device according to claim 26, wherein an alignment film is applied and baked on the pixel electrode and the common electrode, and the alignment is divided by changing a pretilt angle of the liquid crystal in the alignment film. 29. A splay-aligned liquid crystal cell in which the liquid crystal pre-tilt angles at the upper and lower interfaces of a liquid crystal layer disposed between an array substrate having a pixel electrode and a counter substrate having a common electrode have opposite pretilt angles and are aligned in parallel to each other. When no voltage is applied, the liquid crystal display is in a splay alignment. Prior to driving the liquid crystal display, an initialization process is performed to change from the splay alignment to the bend alignment by applying a voltage, and the liquid crystal display is driven in the initialized bend alignment state. An active matrix type liquid crystal display device comprising: a pixel having at least one horizontal electric field applying portion for exciting a transition in a pixel, generating a horizontal electric field by the horizontal electric field applying portion, and generating a horizontal electric field between the pixel electrode and the common electrode; A continuous or intermittent voltage is applied to each pixel to generate transition nuclei for each pixel and to transition the entire pixel from splay alignment to bend alignment. A liquid crystal display device. 30. The liquid crystal display device according to claim 29, wherein a direction of the horizontal electric field generated by the horizontal electric field applying unit is substantially orthogonal to an alignment processing direction. 31. The liquid crystal display device according to claim 29, wherein the horizontal electric field applying section is an electrode deforming section in which a peripheral portion of the pixel electrode is deformed into irregularities in a plane parallel to the substrate surface. 32. The liquid crystal according to claim 29, wherein the horizontal electric field applying unit is an electrode line deforming unit in which a signal electrode line or a gate electrode line is deformed into irregularities in a plane parallel to the substrate surface. Display device. 33. The lateral electric field applying section deforms a peripheral portion of the pixel electrode into irregularities in a plane parallel to the substrate surface, and irregularly deforms a signal electrode line or a gate electrode line corresponding to the irregularities. 30. The liquid crystal display device according to claim 29, wherein the liquid crystal display device is an electrode / electrode line deforming portion. 34. The horizontal electric field applying section is a horizontal electric field applying line deforming section in which the horizontal electric field applying line is deformed into irregularities in a plane parallel to the substrate surface. A signal electrode line or a gate electrode line is disposed in the same direction on an upper layer or a lower layer via an insulating film in at least one of the signal electrode line and the gate electrode line, and is connected to a driving circuit to which the signal electrode line or the gate electrode line is connected. Claim 29
The liquid crystal display device as described in the above. 35. The liquid crystal display device according to claim 34, wherein the line for applying a lateral electric field is cut off from a drive circuit during a normal liquid crystal display after the alignment transition. 36. A splay-aligned liquid crystal cell in which the pretilt angles of the liquid crystal at the upper and lower interfaces of the liquid crystal layer between the array substrate and the opposing substrate are opposite to each other and are aligned in parallel with each other. Prior to driving the liquid crystal display, an initialization process of changing from splay alignment to bend alignment by applying a voltage is performed, and in an active matrix type liquid crystal display device that performs liquid crystal display driving in this initialized bend alignment state, A liquid crystal display device comprising, in one pixel, at least one of a pixel electrode or a common electrode in which a defective portion is formed in at least one place for applying a lateral electric field for transfer excitation. 37. A splay-aligned liquid crystal cell in which the pretilt angles of the liquid crystal at the upper and lower interfaces of the liquid crystal layer between the array substrate and the opposing substrate are opposite to each other and are aligned in parallel with each other. Prior to driving the liquid crystal display, an initialization process of changing from splay alignment to bend alignment by applying a voltage is performed, and in an active matrix type liquid crystal display device that performs liquid crystal display driving in this initialized bend alignment state, In one pixel, there is provided a lateral electric field applying part for transfer excitation, and in one pixel, a pretilt angle of liquid crystal molecules in a partial region of the pixel electrode indicates a first pretilt angle, and a common pixel opposing the pixel electrode. A first alignment region having a second pretilt angle in which a pretilt angle of liquid crystal molecules in a partial region of the electrode is larger than the first alignment region; Third tilt angle
And a second alignment region having a fourth pretilt angle smaller than that of the liquid crystal molecules in another part of the common electrode facing the pixel electrode. Liquid crystal display device. 38. A pulse for applying a pulse-like voltage having a frequency in a range of 0.1 Hz to 100 Hz and a duty ratio in a range of 1: 1 to 1000: 1 between the common electrode and the pixel electrode. The liquid crystal display device according to any one of claims 29 to 37, further comprising a voltage application unit. 39. A liquid crystal layer sandwiched between a pair of substrates,
A phase compensator disposed outside the substrate, and when no voltage is applied, the liquid crystal layer has a splay alignment in which the pretilt angles of the liquid crystal at the upper and lower interfaces are opposite to each other, and the liquid crystal layer is aligned in parallel with each other. Prior to the display driving, the liquid crystal display device performs an initialization process of changing the alignment state of the liquid crystal layer from the splay alignment to the bend alignment by applying a voltage, and performs liquid crystal display driving in the initialized bend alignment state. The pixel includes at least one region where the thickness of the liquid crystal layer is smaller than the surroundings in the pixel, and the electric field intensity applied to the liquid crystal layer in the region is larger than the electric field intensity applied to the surrounding liquid crystal layer. Liquid crystal display device. 40. A liquid crystal layer sandwiched between a pair of substrates,
A phase compensator disposed outside the substrate, and when no voltage is applied, the liquid crystal layer has a splay alignment in which the pretilt angles of the liquid crystal at the upper and lower interfaces are opposite to each other, and the liquid crystal layer is aligned in parallel with each other. Prior to the display driving, the liquid crystal display device performs an initialization process of changing the alignment state of the liquid crystal layer from the splay alignment to the bend alignment by applying a voltage, and performs liquid crystal display driving in the initialized bend alignment state. At least one region having a small liquid crystal layer thickness outside the pixel is included, and the electric field intensity applied to the liquid crystal layer in the region includes:
A liquid crystal display device, wherein the electric field intensity is higher than an electric field intensity applied to a liquid crystal layer in a pixel. 41. A liquid crystal layer sandwiched between a pair of substrates,
A phase compensator disposed outside the substrate, and when no voltage is applied, the liquid crystal layer has a splay alignment in which the pretilt angles of the liquid crystal at the upper and lower interfaces are opposite to each other, and the liquid crystal layer is aligned in parallel with each other. Prior to the display driving, the liquid crystal display device performs an initialization process of changing the alignment state of the liquid crystal layer from the splay alignment to the bend alignment by applying a voltage, and performs liquid crystal display driving in the initialized bend alignment state. A liquid crystal display device comprising at least one electric field concentration portion in a pixel. 42. A display electrode in which an electric field concentration portion provided in the display pixel partially protrudes in a thickness direction of a liquid crystal layer;
42. The liquid crystal display device according to claim 41, wherein the liquid crystal display device is a part of a common electrode or both of them. 43. A liquid crystal layer sandwiched between a pair of substrates,
A phase compensator disposed outside the substrate, and when no voltage is applied, the liquid crystal layer has a splay alignment in which the pretilt angles of the liquid crystal at the upper and lower interfaces are opposite to each other, and the liquid crystal layer is aligned in parallel with each other. Prior to the display driving, the liquid crystal display device performs an initialization process of changing the alignment state of the liquid crystal layer from the splay alignment to the bend alignment by applying a voltage, and performs liquid crystal display driving in the initialized bend alignment state. A liquid crystal display device comprising at least one electric field concentration portion outside a pixel. 44. The liquid crystal display device according to claim 43, wherein the electric field concentration portion is a part of an electrode partially projecting in a thickness direction of the liquid crystal layer. 45. A liquid crystal layer sandwiched between a pair of substrates,
A phase compensator disposed outside the substrate, and when no voltage is applied, the liquid crystal layer has a splay alignment in which the pretilt angles of the liquid crystal at the upper and lower interfaces are opposite to each other, and the liquid crystal layer is aligned in parallel with each other. Prior to the display driving, the liquid crystal display device performs an initialization process of changing the alignment state of the liquid crystal layer from the splay alignment to the bend alignment by applying a voltage, and performs liquid crystal display driving in the initialized bend alignment state. A liquid crystal display device having an opening in an electrode, a part of a common electrode, or both. 46. The active matrix liquid crystal display device including a switching element, wherein the opening is a conduction port for electrically connecting a pixel electrode formed on a flattening film to the switching element. The liquid crystal display device according to claim 45. 47. The phase compensator according to claim 39, wherein the phase compensator includes at least one phase compensator made of an optical medium having a negative refractive index anisotropy and having a main axis hybridly arranged. 47. The liquid crystal display device according to any one of items 46 to 46. 48. The liquid crystal display device according to claim 47, wherein the phase compensator is a phase compensator including at least one positive phase compensator. 49. A method for applying an electric field to a liquid crystal held between a first substrate and a second substrate facing each other to change the orientation of the liquid crystal to a bend orientation, wherein the liquid crystal is sprayed. The elastic constant k11 is set to 10 × 10 ⁻⁷ dyn ≧ k
11 ≧ 6 × 10 ⁻⁷ dyn, and the absolute value of the pretilt angle of the liquid crystal with respect to the first substrate is θ1, and the absolute value of the pretilt angle of the liquid crystal with respect to the second substrate is θ2. Then, 1.57 rad> | θ1−θ2
A driving method for a liquid crystal display device, characterized by satisfying a relationship of | ≧ 0.0002 rad. 50. A method for applying an electric field to a liquid crystal held between a first substrate and a second substrate facing each other to change the orientation of the liquid crystal to a bend orientation, the method comprising: The elastic constant k11 is set to 10 × 10 ⁻⁷ dyn ≧ k11
≧ 6 × 10 ⁻⁷ dyn, and the electric field is an electric field obtained by superimposing a spatially non-uniformly applied auxiliary electric field on a spatially uniformly applied main electric field. When the electric field is E0 and the maximum value of the auxiliary electric field is E1, 1.0
> E1 / E0> 1/100. 51. A method for applying an electric field to a liquid crystal held between a first substrate and a second substrate facing each other to change the orientation of the liquid crystal to a bend orientation, wherein
The absolute value of the pretilt angle of the liquid crystal with respect to the substrate
When the absolute value of the pretilt angle of the liquid crystal with respect to the second substrate is θ2, 1.57 rad> | θ1−θ
2 | ≧ 0.0002 rad, and the electric field is obtained by superimposing a spatially non-uniformly applied auxiliary electric field on a spatially uniformly applied main electric field;
When the main electric field is E0 and the maximum value of the sub electric field is E1, a relationship of 1.0> E1 / E0> 1/100 is satisfied. 52. A method of applying an electric field to a liquid crystal held between a first substrate and a second substrate facing each other to change the orientation of the liquid crystal to a bend orientation, wherein the liquid crystal is sprayed. When the elastic constant k11 is 10 × 10 ⁻⁷ dyn ≧ k11 ≧
In the range of 6 × 10 ⁻⁷ dyn, the absolute value of the pretilt angle of the liquid crystal with respect to the first substrate is set to θ1,
The absolute value of the pretilt angle of the liquid crystal with respect to the substrate
1.57 rad> | θ1−θ2 | ≧ 0.00
02rad, and the electric field is an electric field obtained by superimposing a spatially non-uniformly applied auxiliary electric field on a spatially uniformly applied main electric field.
When 0 and the maximum value of the auxiliary electric field is E1, 1.0>
A method for driving a liquid crystal display device, wherein a relationship of E1 / E0> 1/100 is satisfied. 53. The sub-electric field is applied between a source electrode or a gate electrode of a thin film transistor formed on a surface of the first substrate and a transparent electrode formed on a surface of the second substrate. 53. The method for driving a liquid crystal display device according to claim 50, wherein the driving method is an electric field. 54. The driving method of a liquid crystal display device according to claim 50, wherein the auxiliary electric field is an alternating electric field that is attenuated and vibrated with the passage of time.