JP2002049059A - Liquid crystal element and liquid crystal display panel - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a liquid crystal element which dispenses with a pretreatment and so on and has high speed responsiveness. SOLUTION: In the liquid crystal element comprising a nematic liquid crystal held between two sheets of substrates with a structure capable of being applied with voltage, the liquid crystal is aligned between the two sheets of substrates of which the uniaxial alignment directions are parallel with each other without being applied with an electric field and further the liquid crystal is aligned in such a way that a pretilt of the liquid crystal on the side of one of the substrate is <=10 deg. and a pretilt of the liquid crystal on the side of the other of the substrates in a part deviating from a central position between the substrates close to the substrate boundary is nearly vertical.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid crystal device and a liquid crystal display panel.

[0002]

2. Description of the Related Art Conventionally, as a nematic liquid crystal alignment method, a TN (Twisted Nematic) alignment element in which the rubbing directions of the upper and lower substrates of a liquid crystal cell are rotated by 90 degrees is generally used. An ECB system in which a rubbing process is performed and a nematic liquid crystal is sandwiched between two upper and lower electrode substrates, and an alignment system (a splay alignment) in which a rubbing process is performed in the same direction are also known.

As shown in FIG. 4, there is a method in which the response speed is improved by applying a voltage to a splay alignment rubbed in the same direction to change the alignment to a bend alignment.
Published in 1983 by Bos et al. (Π cell)
(Literature: US Patent No. 4,582,396)

As shown in FIG. 5, Uchida et al. Published a study in 1992 in which such a bend alignment cell was subjected to phase compensation using phase compensators 52 and 53 to improve the viewing angle characteristics. ing. (OCB cell) (Literature 1993 Liquid Crystal Symposium Proceedings 2B13)

[0005] Such a bend alignment type nematic liquid crystal has improved responsiveness and speeded up by suppressing a backflow phenomenon in a liquid crystal response. However, this mode has an alignment state called spray without application of an electric field, and requires a very high voltage and a long time to cause the liquid crystal alignment state to transpose to bend. In addition, it is necessary to always apply a certain voltage in order to maintain the bend state, and if there is a place where the bend state cannot be maintained due to variations in the liquid crystal panel surface, color unevenness caused by the splay alignment state occurs. As a result, a problem more than a point defect in the TN mode or the like has occurred.

[0006]

SUMMARY OF THE INVENTION The present invention has been made to solve such problems of the prior art.
It is an object of the present invention to provide a liquid crystal element having a new liquid crystal alignment mode that does not require pretreatment for displaying a liquid crystal element in the above-described bend alignment mode, and a liquid crystal display panel using the same.

[0007]

That is, the present invention relates to a liquid crystal device having a structure in which a voltage can be applied and having a nematic liquid crystal sandwiched between two substrates, wherein the liquid crystals have uniaxial alignment directions parallel to each other. Are aligned without applying an electric field between the two substrates, and the orientation of the liquid crystal is such that the pretilt of the liquid crystal on one substrate side is 10 ° or less and the center between the substrates on the other substrate side is The liquid crystal element is characterized in that the pretilt of the liquid crystal in a portion deviated from the position toward the substrate interface is substantially vertical.

Further, the pretilt of the liquid crystal on one substrate side is larger than 0 ° and 10 ° or less. Further, a pretilt is provided by using different alignment control layers between the two substrates. Further, the above liquid crystal element displays black by performing phase compensation. Further, the liquid crystal element is driven by using a switching element. Further, the above-mentioned liquid crystal element is characterized in that at least one substrate to which a voltage is applied is given a uniaxial orientation by using a rubbing method for a polymer-based alignment film. Further, the above-described liquid crystal element is characterized in that at least one of the substrates is provided with uniaxial orientation using an oblique evaporation method. Further, the above-mentioned liquid crystal element is characterized in that one of the substrates is used as a reflective type using a reflective electrode.

Further, the present invention is a liquid crystal display panel using the above liquid crystal element.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION In a liquid crystal device in which a nematic liquid crystal is sandwiched and aligned, the present inventors have set the pretilt of the liquid crystal on one substrate side to 10 ° or less, and the other substrate side Without applying an electric field to the orientation of the liquid crystal, the pretilt of the liquid crystal in the portion deviated from the center position between the substrates to the substrate interface has a vertical or substantially vertical portion, and the uniaxial orientation direction between both substrates is parallel to each other. We have invented a new liquid crystal alignment mode liquid crystal element that has a high-speed response by suppressing the backflow phenomenon without requiring special processing to change the alignment state in a certain alignment state.

Normally, in the case of the liquid crystal mode in which black is displayed by the retardation value, as shown in FIG. 5, the phase compensation of a film having retardation, that is, a film in which the directions of molecules constituting the film are aligned, is shown. By using a board to compensate for phase, black is displayed and clear black is displayed.
This liquid crystal element is preferably used after phase compensation.

Further, in the case of a liquid crystal element which displays a gray scale in an analog manner, it is desirable to drive each pixel using a switching element. Further, it is desirable that the pretilt of the liquid crystal on one substrate side be as close to 0 ° as possible (although it is essential that the pretilt is larger than 0 °). The reason for this is that the number of molecules that can impart retardation to the alignment state between the substrates is increased, and sufficient retardation can be obtained at a low voltage.

Further, it is known that when used as a projection type display using a magnifying optical system such as a projection, a streaked alignment state such as rubbing of a polymer alignment film or the like becomes a very serious problem. By setting the pretilt of the liquid crystal on one substrate side as close to 0 ° as possible, the streak alignment state caused by the variation of the in-plane pretilt is reduced. In the present invention, 10 ° or less, preferably 1 ° to
The use of 5 ° improved muscle orientation.

For further improvement, it is more preferable that the other substrate is oriented using an oblique deposition method which has no streak alignment state and can control a high pretilt orientation.

Next, the liquid crystal alignment mode in the present invention will be briefly described. In the normal bend alignment state, the splay alignment is stable when no electric field is applied. By applying a high voltage to this, dislocation to bend orientation occurs. This mode is said to be a high-speed response with less backflow phenomenon caused by reverse twisting or the like seen in the TN mode or the like due to a change in the orientation state of the electric field during On-Off. (See Fig. 6)

The liquid crystal alignment mode of the present invention is characterized in that it has an asymmetric configuration in which the pretilt of the liquid crystal on one substrate is very high with respect to the pretilt of the liquid crystal on the other substrate. FIG. 7 shows an example of this orientation state. By setting the surface 71a of the substrate 71a having a high pretilt up to about 90 °, an alignment state with a small backflow can be easily achieved similarly to the bend alignment state. That is, the pretilt angle θ of the liquid crystal molecules is 70 ° to 89 °, preferably 75 °.
It is desirable that the angle be in the range of 80 ° to 80 °.

Further, when the pretilt on the high pretilt side of the one substrate 71a surface is gradually lowered, the spray state becomes stable below a certain pretilt, and it is necessary to displace to an alignment state having a vertical portion by applying an electric field. Come. In the mode of the present invention, the pretilt of the liquid crystal on one substrate side is set to a state close to 0 °, and the pretilt of the liquid crystal on the other substrate side is not in the splay alignment state but has a portion perpendicular to the substrate between both substrates stably. A feature is that pretilt control is performed in a range. By using this orientation state, there is no need for a voltage for displacing the orientation state or a voltage for maintaining the orientation state.

That is, the liquid crystal element of the present invention is characterized in that the pretilt of the liquid crystal molecules on one substrate side is close to 0 ° and the liquid crystal molecules on the other substrate side are substantially vertical. If the liquid crystal molecules on the other substrate side are not substantially vertical, a splay state occurs below a certain pretilt. When such a splay state is reached, an electric field must be applied. Therefore, the spray state is not a preferable state in the present invention in that an electric field must be applied to eliminate the spray state. The liquid crystal element of the present invention does not require such an electric field application.

Regarding the response speed, the bend orientation from the initial spray is advantageous in that there is no backflow and the response speed is fast, and it is disadvantageous that a bend voltage is required. (High speed) while maintaining (pseudo) bend from the beginning, so that no bend voltage is required, so that the disadvantage of bend orientation from the initial spray can be eliminated.

FIG. 8 is a graph showing the relationship between the bend alignment state, the voltage of the liquid crystal element of the present invention, and the retardation value. The cell thickness is 4 μm, and the liquid crystal is CF manufactured by Seimi Chemical.
-1783 was used. Since this liquid crystal has a large Δn (0.21) and a small viscosity, it was used for driving at a low voltage while maintaining high speed in a thin cell. As shown in the figure, it can be seen that a very wide retardation width can be obtained with the same voltage. This is a feature of the present invention.

In FIG. 8, although the measurement range of the bend alignment mode is narrower than the measurement range of the alignment mode of the present invention, if the voltage is 3 V or less in the bend alignment mode, the state shifts to the spray state, and the retardation rapidly increases. The measurement result was not placed (because it was colored).

A nematic liquid crystal is used for the liquid crystal element of the present invention, but is not particularly limited.

Hereinafter, a specific embodiment of the liquid crystal element of the present invention will be described with reference to FIG. In the liquid crystal element 80 shown in the figure, a cell in which a liquid crystal 85 is sandwiched between a pair of substrates 81a and 81b made of a highly transparent material such as glass and plastic is composed of a pair of polarizing plates 87 whose polarization axes are orthogonal to each other.
a and 87b.

The substrates 81a and 81b are provided with electrodes 82a and 82b made of a material such as In ₂ O ₃ or ITO for applying a voltage to the liquid crystal 85, respectively. Dot-shaped transparent electrodes are arranged in a matrix, and a TFT or MIM (Met (Met)
Al-Insulator-Metal) and other switching elements are connected, and an opposing electrode having a predetermined pattern is formed on one surface of the other substrate or the other substrate to form an active matrix structure.

The electrodes 82a, On 82b, SiO ₂ having a function such as to prevent these short as necessary,
Made of a material such as TiO _2, Ta ₂ O ₅ insulating film 83a, 8
3b are provided respectively.

Further, alignment control films 84a and 84b which are in contact with the liquid crystal 85 and function to control the alignment state are provided. The orientation control films 84a and 84b are orientation control layers for imparting uniaxiality, and include rubbing of polyimide or the like, optical orientation control, and oblique deposition films (SiO, SiOx, CaF
₂ ) etc. are known.

The substrates 81a and 81b are provided with spacers 86.
Are opposed to each other. The spacer 86 determines a distance (cell gap) between the substrates 81a and 81b, and silica beads or the like are used. The cell gap determined here is preferably set in the range of 1 to 10 μm depending on the liquid crystal material, voltage width, and the like.

In the liquid crystal device, the substrates 81a and 81b
At least one of R, G, and B color filters may be provided to provide a color liquid crystal element. Further, a method of performing full-color display using time-division color mixture by sequentially switching the R, G, and B light sources as the light source can also be used.

Incidentally, the liquid crystal element is composed of substrates 81a and 81
b, a transmissive liquid crystal element in which a pair of polarizing plates is provided on both substrates, ie, both the substrates 81a and 81b are translucent substrates, and incident light from one substrate side (for example, light from an external light source) Or a reflection type liquid crystal element in which a polarizing plate is provided on at least one substrate, that is, a reflection plate is provided on one of the substrates 81a and 81b, or one substrate is provided. The present invention can be applied to any type of element that modulates incident light and reflected light by using a reflective material as a member provided on itself or a substrate and emits light to the same side as the incident side.

In the present invention, a drive circuit for supplying a gradation signal to the above-mentioned liquid crystal element is provided, and the value of the retardation is continuously changed by changing the alignment state of the liquid crystal by applying the above-mentioned voltage. A liquid crystal display element which performs gradation display can be formed. For example, by using an active matrix substrate provided with the above-described TFT or the like as one substrate of a liquid crystal element and performing active matrix driving by amplitude modulation with a driving circuit, analog gray scale display can be performed.

Next, an example in which such an active matrix substrate is used in the liquid crystal element of the present invention will be described with reference to FIGS. FIG. 2 schematically shows the liquid crystal element provided with a driving means, mainly focusing on the configuration of one substrate (active matrix substrate).

In the configuration shown in FIG. 2, in a panel section 90 corresponding to a liquid crystal element, horizontal gate lines G1, G2,... In the drawing corresponding to scanning lines connected to a scanning signal driver 91 as driving means. , Corresponding to the information signal lines connected to the information signal driver 92 as the driving means, are provided so as to be orthogonal to each other while being insulated from each other in the vertical direction in the drawing. A thin film transistor (TFT) 94 corresponding to a switching element and a pixel electrode 95 are provided corresponding to the pixel at each intersection (only a 5 × 5 pixel area is shown for simplification). In addition, as a switching element, in addition to TFT, MI
An M element can also be used. Gate lines Gl, G2 ...
Is connected to the gate electrode (not shown) of the TFT 94,
Are connected to a source electrode (not shown) of the TFT 94, and the pixel electrodes 95 are connected to a drain electrode (not shown) of the TFT 94. In such a configuration, the scan signal driver 91 controls the gate line G
, G2... are line-sequentially selected for scanning and a gate voltage is supplied, and an information signal voltage corresponding to information to be written to each pixel is supplied from the information signal driver 92 in synchronization with the scanning selection of the gate line. Are supplied to the lines S1, S2,... And are applied to each pixel electrode via the TFT 94.

FIG. 3 shows an example of a sectional structure of each pixel portion (for one bit) in the panel configuration as shown in FIG. In the structure shown in FIG.
Active matrix substrate 20 having a common electrode 42
Liquid crystal layer 4 having spontaneous polarization between opposing substrates 40 provided with
9 are sandwiched to form a liquid crystal capacitor (C _1c ) 31.

As for the active matrix substrate 20, an example in which an amorphous Si TFT is used as the TFT 94 is shown. The TFT 94 is formed on a substrate 21 made of glass or the like, and the gate lines G1, G2,.
Silicon nitride (SiN) on the gate electrode 22 connected to
x), an a-Si layer 24 is provided via an insulating film (gate insulating film) 23 made of a material such as
4, a source electrode 27 and a drain electrode 28 are provided separately from each other via n ⁺ a-Si layers 25 and 26, respectively.

The source electrode 27 is connected to the source line S shown in FIG.
, S2,..., and the drain electrode 28 is connected to a pixel electrode 95 made of a transparent conductive film such as an ITO film.
The channel protection film 29 covers the a-Si layer 24 of the TFT 94. The TFT 94 has a gate electrode 2 during a period in which the corresponding gate line is selected for scanning.
A gate pulse is applied to 2 to turn it on.

Further, in the active matrix substrate 20, the insulating film 23 (continuously provided with the insulating film on the gate electrode 22) is formed by the pixel electrode 95 and the storage capacitor electrode 30 provided on the glass substrate side of the electrode. A storage capacitor (C _s ) 32 is provided in parallel with the liquid crystal layer 49 by a structure sandwiching the film. When the area of the storage capacitor electrode is large, the aperture ratio is reduced, and thus the storage capacitor electrode is formed of a transparent conductive film such as an ITO film.

The TFT 9 of the active matrix substrate 20
On the pixel electrode 95 and the pixel electrode 95, there is provided an alignment film 43a which has been subjected to a uniaxial alignment process such as a rubbing process for controlling the alignment state of the liquid crystal.

On the other hand, in the counter substrate 40, the glass substrate 41
A common electrode 42 and an alignment film 43b for controlling the alignment state of the liquid crystal are laminated on the entire surface with the same thickness.
In the above-mentioned cell structure, it is preferable to use a phase compensator such as a film sandwiched between a pair of polarizers whose polarization axes are orthogonal to each other, between the polarizers.

In the panel configuration shown in FIGS. 2 and 3, polycrystalline S
A substrate provided with an i (p-Si) TFT can be used. In the case of a reflection type display, an active element can be formed on a single crystal silicon substrate and used as a reflection substrate.

[0040]

EXAMPLES Examples are shown below, but the present invention is not limited to the following examples.

Examples 1 and 2 and Comparative Examples 1 and 2 (Preparation of Cell 1) A film solution of JALS2022 (manufactured by JSR, solution for vertical alignment film) was spin-coated on a glass substrate on which ITO was deposited and patterned. 2m at 80 ° C
It was baked in-pre and baked at 200 ° C. for 60 minutes. This was subjected to a rubbing treatment using a cotton flocking cloth. (Rubbing roller diameter is 80mmφ, roller rotation speed is 100
0 rpm, the substrate surface was pushed 0.5 mm, and the substrate feed speed was 50 mm / s).

A liquid crystal substrate having a reflection electrode is provided with SE-79.
92 (Nissan Chemical's alignment film solution) was applied by spin coating. This is pre-baked at 80 ° C. for 2 minutes,
It was baked at 0 ° C. for 60 minutes. This was subjected to a rubbing treatment using a cotton flocking cloth. (Rubbing roller diameter is 8
0 mmφ, roller rotation speed 1000 rpm, pushing of substrate surface 0.7 mm, substrate feeding speed 50 mm / s
And).

The electrode substrate treated in this way has a thickness of 2.5 μm.
A liquid crystal cell was formed by bonding the substrates so that the rubbing directions of the upper and lower substrates were parallel via a spacer of φ and a sealant. The thickness of the alignment film JALS2022 is 50 nm, and the thickness of the alignment film SE-7992 is 50 n.
m.

(Creation of Cell 2) JALS 2022 (manufactured by JSR, Ltd.) was deposited on a glass substrate on which ITO was deposited and patterned.
A solution for vertical alignment film) was spin-coated. This was pre-fired at 80 ° C. for 2 minutes and fired at 200 ° C. for 60 minutes.

A liquid crystal substrate having a reflective electrode was provided with SE-79.
92 (Nissan Chemical's alignment film solution) was applied by spin coating. This is pre-baked at 80 ° C. for 2 minutes,
It baked at 0 degreeC for 60 minutes. This was subjected to a rubbing treatment using a cotton flocking cloth. (Rubbing roller diameter is 80mmφ, roller rotation speed is 1000rpm, pushing of substrate surface is 0.7mm, substrate feeding speed is 50mm / s
And).

A liquid crystal cell was formed by bonding the thus treated electrode substrate via a 2 μmφ spacer and a sealing agent so that the rubbing directions of the upper and lower substrates were parallel. The thickness of the alignment film JALS2022 is 30 nm, and the thickness of the alignment film SE-7992 is 50 nm.

(Formation of Cell 3) A glass substrate on which ITO was deposited by patterning and a liquid crystal substrate having a reflective electrode
An alignment film solution of E-7992 (Nissan Chemical's solution for alignment film) was spin-coated. This was pre-fired at 80 ° C. for 2 minutes and fired at 200 ° C. for 60 minutes. This was subjected to a rubbing treatment using a cotton flocking cloth. (Rubbing roller diameter is 80 mmφ, roller rotation speed is 1000 rpm, pushing of substrate surface is 0.7 mm, substrate feeding speed is 50 m
m / s).

A liquid crystal cell was formed by laminating the thus treated electrode substrate via a 3 μmφ spacer and a sealing agent so that the rubbing directions of the upper and lower substrates were parallel. Note that the thickness of the alignment film SE-7992 is 50 nm.

(Formation of Cell 4) Oblique evaporation was performed on a liquid crystal substrate having a reflective electrode using SiO. (Film thickness 120
nm, deposition rate 0.1 nm / s, deposition angle 75 °).

An alignment film solution of SE-7992 (Nissan Chemical Industries, alignment film solution) was spin-coated on a glass substrate on which ITO was deposited and patterned. This at 80 ° C for 2 minutes
It was pre-fired and fired at 200 ° C. for 60 minutes. This was subjected to a rubbing treatment using a cotton flocking cloth. (Rubbing roller diameter is 80mmφ, roller rotation speed is 1000r
pm, the substrate surface was pushed 0.7 mm, and the substrate feed speed was 50 mm / s).

A liquid crystal cell was formed by laminating the thus treated electrode substrate via a 3 μmφ spacer and a sealing agent so that the rubbing directions of the upper and lower substrates were parallel. Note that the thickness of the alignment film SE-7992 is 50 nm.

A nematic liquid crystal (manufactured by Seimi Chemical Co., Ltd., CF-1783) was injected under reduced pressure into each of the above prepared cells 1 to 4 to prepare respective liquid crystal elements. In each cell, a plurality of polycarbonate phase compensators were used so as to compensate for black in a normally white state in which black is displayed when a voltage is applied. The polarizing plate was measured using a beam splitter and an optical system as shown in FIG.

FIG. 9 shows the beam splitter 12.
A phase compensator (not shown) is provided between the liquid crystal element 14 and the liquid crystal element 14. In the case of normally white, in order to make black on the high voltage side, a “phase compensator” having the same retardation as the retardation when applying 7 V (from the graph of FIG. 8, about 110 nm) is connected to the slow axis and the liquid crystal element. They are arranged so that the rubbing direction is orthogonal to 90 °. The beam splitter was prepared for arranging the deflecting plate in crossed Nicols with the reflection element. In a normal white light reflecting element, the other polarizing plate and the beam splitter may not be used as long as they are arranged at λ / 4 = 560/4 = 140 nm of the central wavelength in the visible region.

Table 1 shows the results of measuring the characteristics of each liquid crystal element at room temperature of 25 ° C.

[0055]

[Table 1]

(Note) 1) The retardation width in the voltage range of 0 to 7 V (that is,
(The value obtained by subtracting the minimum value from the maximum value of the retardation value, measured with a Bellec compensator) 2) The response speed is in the range of 0 to 7 V (4 to 7 V in Comparative Example 2).
Measured at 0 Hz square wave τon indicates switching from white state to black state,
Response speed from 100% white to 10% black. τo
ff indicates switching from the black state to the white state, and is a response speed from 0% black to 90% of the white state. 3) For pretilt, a cell was separately formed so that the substrate having the same uniaxial orientation in the upper and lower directions was antiparallel to the uniaxial orientation direction. It was determined by converting the cell thickness from Δn of the used liquid crystal and the measured value of the retardation of the prepared cell.

In Example 1, a response speed comparable to that of the bend state was exhibited without requiring a bend voltage (pretreatment) peculiar to the bend orientation state or a voltage (holding voltage) for maintaining the bend state. In Comparative Example 2, a high voltage of about 15 V was required for the bend-forming process, and it took 20 cm for 1 cm ² to bend.
It took about min. Furthermore, a voltage of 4 V was required to maintain the bend state. Comparative Example 1 has an orientation state called HAN orientation as shown in FIG. 11, but it can be seen that the response speed is remarkably improved by setting the pretilt on one side to a lower direction from 90 °. This is probably because the backflow phenomenon was reduced.

Examples 3 and 4 The liquid crystal devices of Examples 1 to 4 were evaluated for the state of streak alignment. The liquid crystal elements of Examples 3 and 4 use cells 5 and 6 in which the pretilt is adjusted by changing the thickness of the alignment film while keeping the rubbing strength of the vertical alignment film (JALS2022) constant, as in Example 1. Was. The same liquid crystal as in Examples 1 and 2 was used.

The orientation of the muscles was observed under a microscope (200 ×). Table 2 shows the results.

[0060]

[Table 2]

In Example 4, the streak orientation state was remarkably observed even in a completely black state (△). In contrast, Examples 1 and 3
There were some streaks in the halftone state (調). On the other hand, in Example 2, no muscle alignment state was observed (◎).

Examples 5 and 6 and Comparative Example 3 Under the same conditions as in Examples 1 and 2 and Comparative Example 2, one substrate was changed from a reflective electrode substrate to a transmissive glass substrate, and only the spacer diameter was changed. Created a cell. Table 3 shows the results of measuring the characteristics of each liquid crystal element at a room temperature of 25 ° C. The measurement conditions and the like are the same as in Tables 1 and 2.

[0063]

[Table 3]

As a result, a result similar to that of the reflection type was obtained.
Regarding the response speed, the cell thickness of all the liquid crystal elements is almost twice that of the reflection type, and this is due to the decrease in the electric field intensity.

Example 7 A liquid crystal element using a switching element was evaluated.
A substrate having a TFT configuration as shown in FIG. 3 was prepared.
The conditions for forming the cells were such that the printing method was used only when the alignment film was applied using Example 6. A data driver and a gate driver were mounted as shown in FIG. Figure 10
A liquid crystal element was displayed by applying a waveform as shown in FIG. It was installed together with the corresponding phase compensator and evaluated. As a result, as in the case of Example 6, the dislocation voltage was not particularly required, and high-speed response was exhibited.

[0066]

As described above, according to the present invention,
By forming a specific alignment state on two substrates, a liquid crystal element and a liquid crystal display panel having high-speed response without requiring pretreatment or the like can be provided.

[Brief description of the drawings]

FIG. 1 is a schematic view showing one embodiment of a liquid crystal element of the present invention.

FIG. 2 is a diagram schematically showing a liquid crystal element of the present invention provided with a driving means, with a focus on the structure of one substrate.

3 is a schematic diagram showing an example of a cross-sectional structure of each pixel portion (for one bit) in the panel configuration shown in FIG.

FIG. 4 is an explanatory view showing a state in which a voltage is applied to a splay alignment of a conventional liquid crystal element to change the alignment to a bend alignment.

FIG. 5 is an explanatory diagram for performing phase compensation on a bend alignment cell.

FIG. 6 is an explanatory diagram showing an example of an alignment state in a liquid crystal alignment mode of the present invention.

FIG. 7 is an explanatory diagram showing an example of an alignment state in a liquid crystal alignment mode of the present invention.

FIG. 8 is a graph showing a relationship between a bend alignment state, a voltage of the liquid crystal element of the present invention, and a retardation value.

FIG. 9 is an explanatory diagram showing an optical system used for measuring a liquid crystal element of an example.

FIG. 10 is a diagram showing applied waveforms used for measuring the liquid crystal element of Example 7.

FIG. 11 is an explanatory diagram illustrating an alignment state of a liquid crystal element of Comparative Example 1.

[Explanation of symbols]

Reference Signs List 11 light source 12 beam splitter 13 polarizing plate 14 liquid crystal element 15 observer 20 active matrix substrate 21 substrate 22 gate electrode 23 insulating film (gate insulating film) 24 a-Si layer 25, 26 n ⁺ a-Si layer 27 source electrode 28 drain Electrode 29 Channel protective film 30 Storage capacitor electrode 31 Liquid crystal capacitor 32 Common electrode 40 Opposite substrate 41 Glass substrate 42 Common electrode 43a, 43b Alignment film 49 Liquid crystal layer 71a, 71b Substrate 80 Liquid crystal element 8la, 8lb Substrate 82a, 82b Electrode 83a, 83b Insulating film 84a, 84b Alignment control film 85 Liquid crystal 86 Spacer 87a, 87b Polarizer 90 Panel 91 Scan signal driver 92 Information signal driver 94 Thin film transistor (TFT) 95 Pixel electrode

Claims (9)

[Claims] 1. A liquid crystal element having a nematic liquid crystal sandwiched between two substrates having a structure to which a voltage can be applied. In the liquid crystal element, an electric field is applied between the two substrates whose uniaxial alignment directions are parallel to each other. The liquid crystal is aligned without applying the voltage, and the liquid crystal has an orientation that the pretilt of the liquid crystal on one substrate side is 1
A liquid crystal element characterized in that a pretilt of liquid crystal is substantially vertical at a portion which is less than 0 ° and is deviated from a center position between substrates on the other substrate side to a substrate interface. 2. The pretilt of liquid crystal on one substrate side is 0 °.
2. The liquid crystal device according to claim 1, wherein the angle is larger than 10 [deg.]. 3. A pretilt is provided by using different orientation control layers between two substrates.
The liquid crystal element according to the above. 4. The liquid crystal device according to claim 1, wherein black is displayed by phase compensation. 5. The liquid crystal element according to claim 1, wherein the liquid crystal element is driven by using a switching element. 6. The method according to claim 1, wherein at least one of the substrates to which a voltage is applied is provided with a uniaxial orientation using a rubbing method for a polymer-based alignment film. Liquid crystal element. 7. The liquid crystal device according to claim 1, wherein at least one of the substrates is provided with uniaxial orientation by using an oblique deposition method. 8. The liquid crystal device according to claim 1, wherein one of the substrates is used as a reflection type by using a reflection electrode. 9. A liquid crystal display panel using the liquid crystal element according to claim 1.