JP3005936B2 - Liquid crystal display device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid crystal display device using a ferroelectric liquid crystal having a ferroelectric phase and / or an antiferroelectric phase (including an antiferroelectric liquid crystal), and more particularly to a stable gradation display. And a liquid crystal display device capable of:

[0002]

2. Description of the Related Art As a ferroelectric liquid crystal display device capable of gradation display, it has been proposed to use a ferroelectric liquid crystal having a helical pitch of a chiral smectic phase smaller than a substrate spacing of the display device. As this type of ferroelectric liquid crystal, a liquid crystal having a memory property is called an SBF liquid crystal, and a non-memory liquid crystal is called a DHF liquid crystal (“LIQUID CRYSTALS”, 198).
9, Vol. 5, No. 4, pp. 1171 to 1177).

A liquid crystal display device using a DHF liquid crystal is DH
The F liquid crystal is sealed between a pair of substrates in a state of having a spiral structure, and is formed by sandwiching the pair of substrates between a pair of polarizing plates. In a DHF liquid crystal, when a voltage having a sufficiently large absolute value is applied between electrodes facing each other with a liquid crystal layer interposed therebetween, the average orientation direction of liquid crystal molecules becomes the first direction according to the polarity of the applied voltage. One of a first alignment state (first ferroelectric phase) and a second alignment state (second ferroelectric phase) in which the average alignment direction of the liquid crystal molecules is in the second direction is applied. When the absolute value of the voltage is smaller than the voltage at which the first alignment state or the second alignment state is set, the average alignment direction of the liquid crystal molecules is in the first and second directions due to the helical distortion of the molecular alignment. An intermediate orientation state between them is obtained. A halftone can be displayed using this intermediate orientation state.

In a liquid crystal display device using SBF liquid crystal, the ratio of a region composed of liquid crystal molecules in a first alignment state to a region composed of liquid crystal molecules in a second alignment state changes according to an applied voltage. The gradation is displayed using the change of.

On the other hand, the antiferroelectric liquid crystal has two ferroelectric phases and one antiferroelectric phase, and the liquid crystal molecules have three stable states and are also aligned in an intermediate alignment state by a precursor phenomenon or the like. A gradation can be displayed using this intermediate alignment state.

[0006]

In a liquid crystal having a ferroelectric phase and / or an antiferroelectric phase, a smectic layer of liquid crystal molecules when a predetermined positive voltage shown in FIGS. 13A and 13B is applied. (Tilt angle) θl with respect to the normal direction of
It is desirable that the tilt angles θ2 of the liquid crystal molecules when a predetermined voltage of negative polarity is applied are opposite in direction and equal in value. That is, it is desirable that the applied voltage-transmittance characteristics be equal to the application of a voltage of the opposite polarity. However, actually, the tilt angles θl and θ2 of the liquid crystal molecules when voltages having opposite polarities are applied are different from each other. For this reason, the transmittance of the liquid crystal display element changes according to the polarity of the applied voltage,
Beam La may occur depending on the display gradation, display there is a problem that not stable.

The present invention has been made in view of the above situation, and has as its object to provide a liquid crystal display device having a ferroelectric phase capable of performing stable gradation display.

[0008]

In order to achieve the above object, a liquid crystal display device according to a first aspect of the present invention comprises:
A first substrate on which a first electrode is formed, a second substrate on which a counter electrode facing the first electrode is formed, and a first substrate formed on the first substrate and the first electrode. A first alignment process is performed in a second direction, and a second alignment process is performed in a second direction opposite to the first direction so as to overlap the first alignment process; A second electrode disposed between the first substrate and the second substrate and having a layer structure of a smectic C phase;
Polarity applied between the pole and the second electrode according to different voltages
A first alignment state in which liquid crystal molecules are substantially aligned in a first direction.
State and the second alignment in which the liquid crystal molecules are substantially aligned in the second direction
The average of the liquid crystal molecules according to the state and the applied voltage changes
A typical arrangement direction is between the first direction and the second direction.
During each alignment to an intermediate orientation state that is an arbitrary direction
And an antiferroelectric liquid crystal having an inter-alignment state .

A liquid crystal display device according to a second aspect of the present invention includes a first substrate on which a first electrode is formed, and a second substrate on which a second electrode opposed to the first electrode is formed. 2 substrate, and disposed between the first and second substrates, having a smectic C-phase layer structure, wherein the polarity applied between the first electrode and the second electrode is different according to a voltage. A first alignment state in which liquid crystal molecules are substantially aligned in a first direction and a second alignment state in which liquid crystal molecules are substantially aligned in a second direction are applied.
The liquid crystal molecules have intermediate alignment states in which the average alignment direction of the liquid crystal molecules is in an arbitrary alignment state between the first direction and the second direction in accordance with a change in the applied voltage. A ferroelectric liquid crystal, substantially the same as the liquid crystal molecules formed on the first substrate and the first electrode and tilting to the right and left with respect to the normal of the liquid crystal layer; And an orientation film that gives substantially the same tilt angle to the liquid crystal molecules when voltages of the same value with different polarities are applied to the liquid crystal, and the first and second substrates interposed therebetween. One polarizing plate that is disposed and has an optical axis set in a predetermined direction, and the other polarizing plate whose optical axis is set to be orthogonal or parallel to the optical axis of the one polarizing plate, is provided. It is characterized by.

[0010]

According to the liquid crystal display device of the first aspect, the alignment film is subjected to the alignment process a plurality of times in the opposite direction. By this processing, even if the polarity of the applied voltage changes, the tilt angles of the liquid crystal molecules become equal. Therefore, possible by the positive polarity applied voltage and the negative polarity applying electrode of obtaining the same display characteristics and Do Ri, it is possible to display a clear tone.

According to the liquid crystal display element of the second aspect, when voltages having different polarities and the same value are applied, the alignment film gives substantially the same tilt angle to the liquid crystal molecules. Therefore, even if the polarity of the applied voltage changes, the tilt angles of the liquid crystal molecules become equal if the values of the applied voltages are equal. For this reason, the same display characteristics can be obtained by the voltage of the polarity and the voltage of the negative polarity, and a clear gradation can be displayed.
Can be .

[0012]

First, the structure of a ferroelectric liquid crystal display device according to this embodiment will be described. FIG. 1 is a sectional view of a ferroelectric liquid crystal display device, and FIG. 2 is a plan view of a transparent substrate on which a pixel electrode and an active device of the ferroelectric liquid crystal display device are formed. This ferroelectric liquid crystal display element is of an active matrix type, and as shown in FIG. 1, a liquid crystal cell formed by sealing a liquid crystal 11 between a pair of transparent substrates (eg, glass substrates) 1 and 2. A pair of polarizing plates 1 arranged with the liquid crystal cell interposed therebetween
3 and 14.

In FIG. 1, a lower transparent substrate (hereinafter, referred to as a lower substrate) 1 has a pixel electrode 3 made of a transparent conductive material such as ITO as shown in FIGS. Are connected in a matrix.

As shown in FIG. 2, a gate line 5 is wired between rows of the pixel electrodes 3, and a data line (gradation signal line) 6 is wired between columns of the pixel electrodes 3. Each TFT
4 is connected to the corresponding gate line 5,
The drain electrodes are connected to corresponding data lines 6. The gate line 5 is connected to a row driver 21 and the data line 6 is connected to a column driver 22. The row driver 21 scans the gate line 5 by applying a gate voltage described later. On the other hand, the column driver 22 receives the image data and applies a data signal corresponding to the image data to the data line 6.

In FIG. 1, an upper transparent substrate (hereinafter, upper substrate) 2 is provided with a counter electrode 7 which is opposed to each pixel electrode 3 of the lower substrate 1 and to which a reference voltage V0 is applied. Alignment films 8 and 9 are provided on the electrode formation surfaces of the lower substrate 1 and the upper substrate 2, respectively. The alignment films 8 and 9 are made of an organic polymer compound such as polyimide. Alignment film 8
Is subjected to an orientation treatment in a direction 11D indicated by a broken line in FIG. 3, and subsequently, the same surface is rubbed in a direction 11C opposite to the direction 11D. That is, the alignment treatment is performed twice in different directions.

Considering the relationship between the alignment film and the liquid crystal molecules using an elastic body model, as shown in FIG. 13A, the elastic coefficient K1 of the liquid crystal molecules when the liquid crystal molecules tilt to the right of the normal to the smectic layer is expressed as As shown in FIG. 13B, the elastic coefficient K2 of the liquid crystal molecules when the liquid crystal molecules tilt to the left of the normal to the smectic layer is different. Therefore, even if the absolute value is applied a voltage equal, a difference is generated in the tilt angle theta ₂ of the right tilt tilt angle theta ₁ and left tilt.

The alignment film 8 is rubbed once in the opposite direction. Therefore, the elastic coefficient K ₁ for the right tilt by first rubbing with the elastic coefficient K ₂ 'for the left tilt by second rubbing is averaged, also the elastic modulus for the left tilt by first rubbing K The elastic coefficient K ₁ ′ for right tilt by the _second and second rubbings is averaged, and the elastic coefficient of right tilt and the elastic coefficient of left tilt are averaged to be substantially equal. Accordingly, the tilt angle θ ₁ of the liquid crystal molecules when a predetermined positive voltage is applied is equal to the tilt angle θ ₂ of the liquid crystal molecules when a predetermined negative voltage is applied.

For example, as shown in FIG. 4, the lower end of the rubbing cloth 21 wound around the rubbing drum 31 of the rubbing device is pressed into the alignment film 8 by about 0.55 mm, and the rubbing drum is driven at 500 rpm. The first rubbing direction 11D by moving at a speed of 5 mm / sec while rotating
Then, the rubbing cloth is rubbed in the second rubbing direction 11C by moving the rubbing drum in the opposite direction with the lower end of the rubbing cloth pressed into the alignment film 8 by about 0.45 mm.

The alignment film 9 is not subjected to an alignment treatment. Further, the alignment film 9 may be a protective film or the like. Or,
The counter electrode 7 may directly contact the liquid crystal 11.

The lower substrate 1 and the upper substrate 2 are bonded to each other at the outer peripheral edge thereof via a frame-shaped sealing material 10. A liquid crystal 11 is sealed in a region surrounded by the substrates 1 and 2 and the sealing material 10. The liquid crystal 11 is a chiral smectic C
The helical pitch of the phase is smaller than the distance between the substrates 1 and 2 and the ferroelectric liquid crystal (DH
F liquid crystal). The liquid crystal 11 has a helical pitch of 700 nm to 400 nm or less (for example, 40 nm) which is a wavelength in the visible light band.
(0 nm to 300 nm), a spontaneous polarization is large, and the cone angle is about 27 ° to 45 °. The thickness of the layer of the liquid crystal 11, that is, the gap length is uniformly maintained by the gap material 12.

The liquid crystal 11 forms a uniform layer structure with the normal of the layer having the layer structure of the chiral smectic C phase substantially oriented in the direction 11 C of the alignment treatment of the alignment film 8. The normal direction of the layer having the layer structure does not always coincide with the direction 11C of the alignment treatment. Since the helical pitch of the liquid crystal 11 is smaller than the substrate pitch, the liquid crystal 11 is sealed between the substrates 1 and 2 with a helical structure. When a voltage whose absolute value is sufficiently large is applied between the pixel electrode 3 and the counter electrode 7, the liquid crystal 11 has a first alignment direction in which the alignment direction of the liquid crystal molecules is substantially the first alignment direction according to the polarity of the applied voltage. The alignment state is set to one of the second alignment states in which the alignment direction of the liquid crystal molecules is substantially the second alignment direction. Further, when a voltage whose absolute value is lower than the voltage for aligning the liquid crystal molecules in the first or second alignment state is applied between the pixel electrode 3 and the counter electrode 7, the helix of the molecular arrangement of the liquid crystal 11 is distorted, and An intermediate alignment state is obtained in which the average alignment direction is a direction between the first alignment direction and the second alignment direction.

A pair of polarizing plates 1 are provided above and below the liquid crystal display element.
3 and 14 are arranged. Transmission axis 13A of polarizing plate 13
Is set substantially parallel to the direction 11C of the above-described alignment processing,
The transmission axis 14A of the polarizing plate 14 is set to be orthogonal to the transmission axis 13A. Note that, in FIG.
A and 11B show the alignment directions (director directions) of the liquid crystal molecules in the first and second alignment states of the liquid crystal 11.

As shown in FIG. 3, the ferroelectric liquid crystal display device in which the transmission axes 13A and 14A of the polarizing plates 13 and 14 are set,
In the first or second alignment state in which the liquid crystal molecules are aligned in the first or second alignment direction 11A, 11B, the transmittance becomes highest (the display is the brightest), and the liquid crystal molecules are shifted to the smectic phase layer. The transmittance is lowest (the display is darkest) when oriented in an intermediate direction 11C substantially parallel to the normal direction.

The director of the liquid crystal 11 determines the alignment directions 11A and 11B according to the polarity of the applied voltage and the voltage value (absolute value).
Varies continuously between Therefore, the transmittance of the ferroelectric liquid crystal display device can be changed continuously.

Next, the characteristics of the liquid crystal 11 will be described.
In this embodiment, the period is relatively long (0.1 Hz
About) When a triangular wave voltage is applied, the optical response characteristic thereof changes continuously as shown in FIG. 5 and has no threshold value. It is desirable that the hysteresis of the optical response characteristic is small.

Next, a method of driving the liquid crystal display device having the above configuration will be described with reference to FIGS. FIG. 6 (A)
FIG. 6 shows a waveform of a gate signal applied by the row driver 21 to the gate line 5 connected to the TFT 4 in the first row.
(B) shows the waveform of the data signal applied to the data line 6 by the column driver 22. To facilitate understanding, only the data signals for the pixels in the first row are shown, and the data signals for the other rows are not shown.

In FIGS. 6A and 6B, TF indicates one frame period, TS indicates a selection period of the pixels in the first row, and TO indicates a non-selection period. Each selection period TS is, for example, about 60 μm.
Seconds. In this embodiment, as shown in FIG. 6B, during the selection period TS of two consecutive frames TFODD (odd-numbered frame) and TFeven (even-numbered frame), the polarity is changed according to the display gradation. Conversely, a drive pulse (write pulse) having the same absolute voltage value VD, -VD is applied to the data line 6. That is, for one image data (gradation signal), two driving pulses having the same absolute value of the voltage and the positive and negative polarities are applied to the two frames TF.
One is applied to each of odd and TFeven selection periods TS.

In this driving method, the minimum value of the write voltage VD is set to V0, and the maximum value Vmax is set to a value slightly lower than the voltage (Vsat in FIG. 5) at which the transmittance is saturated.
The write voltage VD is controlled in the range of 0 to Vmax.

When the ferroelectric liquid crystal display device is driven by using the gate signal and the data signal having the waveforms as described above,
During the selection period TS of each row, the drive pulse voltage (write voltage) VD or -VD is turned on by the gate signal.
The voltage is applied to the pixel electrode 3 via the FT 4. When the gate signal is turned off and the non-selection period TO is reached, the TFT 4 is turned off,
The voltage corresponding to the writing voltage VD or −VD is applied to the pixel electrode 3.
And the capacitance (pixel capacitance) formed by the counter electrode 7 and the liquid crystal 11 therebetween. Therefore, the non-selection period TO
During this period, the transmittance of the pixel is maintained at a value corresponding to the holding voltage of the pixel capacitance, that is, a value corresponding to the writing voltage VD or −VD.

In this embodiment, a liquid crystal 11 whose transmittance with respect to a change in applied voltage continuously changes is used, and the optical arrangement shown in FIG. 3 is employed.
The transmittance with respect to the absolute value of the writing voltage VD or -VD is uniquely determined, and the transmittance can be controlled by the absolute value of the writing voltage VD or -VD to realize gray scale display.

Moreover, the alignment film 8 is rubbed twice in the opposite direction. Therefore, as shown in FIG. 13A, the tilt θ of the liquid crystal molecules when the write voltage VD is applied.
₁ is substantially equal to the tilt θ ₂ of the liquid crystal molecules when the writing voltage −VD shown in FIG. 13B is applied. Therefore, it is possible to prevent the transmittance from fluctuating due to the polarity of the applied voltage, and to obtain a desired display gradation regardless of the polarity.

An experiment was conducted to confirm the operation of the liquid crystal display device of this embodiment. First, FIG. 7 shows a change in transmittance of the liquid crystal display element when the voltage VD is changed by driving the liquid crystal display element of this embodiment by the driving method shown in FIG. As a comparative example, FIG. 8 shows changes in the voltage and the transmittance of the liquid crystal display device including the alignment film 8 that has been subjected to the alignment process once in the direction 11C.
Shown in

As shown in FIG. 7, in the liquid crystal display device of this embodiment, there is almost no difference between the transmittance for the positive applied voltage VD and the transmittance for the negative applied voltage -VD. On the other hand, in the liquid crystal display element of the comparative example shown in FIG. 8, the difference between the transmittance for the positive applied voltage VD and the transmittance for the negative applied voltage −VD is large. From this experiment, it was confirmed that this example provided a liquid crystal display device having small anisotropy in elastic energy between the alignment film and the liquid crystal molecules and excellent characteristics.

In the above embodiment, a DHF liquid crystal, which is a ferroelectric liquid crystal, is used as the liquid crystal 11, but an SBF liquid crystal or an antiferroelectric liquid crystal (hereinafter, AFLC) may be used. Since the spiral pitch of the AFLC is larger than the substrate interval, the AFLC is sealed between the substrates 1 and 2 in a state where the spiral structure has disappeared, and the transmission axes 13A and 14A of the pair of polarizing plates 13 and 14 are provided.
A is arranged as shown in FIG. AF of this embodiment
As shown in FIGS. 9 to 12, an LC whose transmittance changes continuously with a change in applied voltage and does not have a definite threshold is used. Such an optical property can be obtained by (1)
AFLC in which the double helix drawn by the smectic CA ^* -phase liquid crystal is distorted according to the applied voltage. (3) AFLC in which liquid crystal molecules move along the cone by an angle corresponding to the applied voltage,
(4) The liquid crystal molecules in one of the two alignment states are switched to the other alignment state according to the applied voltage, and the ratio is changed by the applied voltage. Can be.

In the above embodiment, the alignment film 8 is subjected to the rubbing treatment twice (rubbing). However, the number of times of rubbing may be larger. However, it is desirable to perform rubbing in the opposite direction even number times. Although the alignment process is performed only on the alignment film 8, the alignment process may also be performed on the alignment film 9 on the counter substrate 2 side. Also in this case, it is desirable that the alignment film 9 is also subjected to the alignment process in the opposite direction a plurality of times.

For example, in the above embodiment, two positive and negative drive pulses are applied to the liquid crystal 11 for each display data.
One drive pulse may be applied to one display data. For example, if the display data is I1, I2, I3,
In the case of I4 ..., the applied voltage is VD1, -VD2, V
D3, -VD4... May be applied.

In FIG. 3, the transmission axis 13A of one polarizing plate 13 is made coincident with the direction 11C between the first direction 11A and the second direction 11B, and the transmission axis 14A of the other polarizing plate 14 is set to the transmission axis 13A. However, the transmission axis 14A of the other polarizing plate 14 may be parallel to the transmission axis 13A. Further, the absorption axis of one polarizing plate 13 is made to coincide with a direction 11C intermediate between the first direction 11A and the second direction 11B,
The absorption axis of the other polarizing plate 14 may be orthogonal to the absorption axis of the one polarizing plate 13.

Further, in the above embodiment, the present invention has been described by taking an active matrix type liquid crystal display element as an example. However, the present invention can be similarly applied to a simple matrix type liquid crystal display element.

[0039]

As described above, according to the present invention, since the alignment film is subjected to the alignment treatment a plurality of times in different directions, the tilt of the liquid crystal molecules when a predetermined positive voltage is applied and the negative electrode When a predetermined voltage is applied to the liquid crystal molecules, the tilt of the liquid crystal molecules is substantially equal, and the transmittance is also substantially equal. Therefore, a desired gradation can be reliably displayed using the antiferroelectric liquid crystal .

[Brief description of the drawings]

FIG. 1 is a sectional view showing the structure of a liquid crystal display device according to one embodiment of the present invention.

FIG. 2 is a plan view showing a configuration of a lower substrate of the liquid crystal display element shown in FIG.

FIG. 3 is a plan view showing directions of transmission axes of upper and lower polarizing plates and alignment directions of liquid crystal molecules.

FIG. 4 is a diagram illustrating a method of rubbing an alignment film.

FIG. 5 is a graph showing the relationship between applied voltage and transmittance.

6A and 6B are waveform diagrams for explaining a method of driving a ferroelectric liquid crystal display element according to an embodiment of the present invention; FIG. 6A is a diagram illustrating a method of driving a ferroelectric liquid crystal display element according to an embodiment of the present invention; FIG. 5 is a diagram showing a waveform of a gate signal supplied to a gate line by the following equation. (B) is a diagram showing an example of a waveform of a data signal supplied to a data line by a method of driving a ferroelectric liquid crystal display element according to one embodiment.

FIG. 7 is a graph showing a change in transmittance when the liquid crystal display element of this embodiment is driven using the driving waveform shown in FIG.

8 is a graph showing a change in transmittance when a liquid crystal display element of a comparative example is driven using the driving waveform shown in FIG.

FIG. 9 is a graph showing the relationship between the applied voltage and the transmittance of the antiferroelectric liquid crystal usable in the embodiment of the present invention.

FIG. 10 is a graph showing the relationship between the applied voltage and the transmittance of the antiferroelectric liquid crystal usable in the embodiment of the present invention.

FIG. 11 is a graph showing the relationship between the applied voltage and the transmittance of the antiferroelectric liquid crystal usable in the embodiment of the present invention.

FIG. 12 is a graph showing the relationship between the applied voltage and the transmittance of the antiferroelectric liquid crystal usable in the embodiment of the present invention.

13A and 13B are diagrams illustrating a relationship between an applied voltage and the orientation of liquid crystal molecules. FIG. 13A illustrates the orientation when a positive voltage is applied,
(B) shows the orientation when a negative voltage is applied.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Transparent substrate, 2 ... Transparent substrate, 3 ... Pixel electrode, 4 ...
TFT, 5 ... gate line, 6 ... data line, 7 ...
・ Counter electrode, 8 ・ ・ ・ Alignment film, 9 ・ ・ ・ Alignment film, 10 ・ ・ ・ Seal material, 11 ・ ・ ・ Liquid crystal, 12 ・ ・ ・ Gap material, 13 ・ ・ ・ Polarizer, 14 ・ ・ ・ Polarized light Plate, 21: row driver, 22: column driver, 31: rubbing drum, 32: rubbing cloth

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-64-55527 (JP, A) JP-A-2-153322 (JP, A) JP-A-2-222930 (JP, A) JP-A-4- 57020 (JP, A) (58) Field surveyed (Int. Cl. ⁷ , DB name) G02F 1/1337

Claims (4)

(57) [Claims] A first substrate on which a first electrode is formed; a second substrate on which a counter electrode facing the first electrode is formed; a first substrate and a first electrode; And a first orientation treatment is performed in a first direction in a first direction, and a second orientation treatment is performed in a second direction opposite to the first direction so as to overlap the first orientation treatment. An alignment film, disposed between the alignment film and the second substrate ;
A first electrode and a second electrode, each having a
Depending on the voltage applied between the different polarities, the liquid crystal molecules
A first alignment state substantially aligned in a first direction;
Are substantially aligned in the second direction, and
The average alignment direction of the liquid crystal molecules changes according to the change in the applied voltage.
Any direction between the first direction and the second direction.
Has an intermediate alignment state in which each is aligned to an intermediate alignment state.
A liquid crystal display device comprising: an antiferroelectric liquid crystal; 2. A first substrate on which a first electrode is formed, and a second substrate on which a second electrode opposed to the first electrode is formed.
A substrate having a smectic C phase layer structure disposed between the first and second substrates and having a different polarity applied between the first electrode and the second electrode. A first alignment state in which molecules are substantially aligned in a first direction, a second alignment state in which liquid crystal molecules are substantially aligned in a second direction, and an applied voltage
The average alignment direction of the liquid crystal molecules changes in accordance with the first
And an antiferroelectric liquid crystal having an intermediate alignment state in which the liquid crystal molecules are aligned in an intermediate alignment state that is an arbitrary direction between the first direction and the second direction. The liquid crystal molecules that are formed and tilt to the right and the liquid crystal molecules that tilt to the left with respect to the normal of the liquid crystal layer have substantially the same elastic modulus, and the same voltage with different polarities is applied to the liquid crystal. And an alignment film that gives substantially the same tilt angle to the liquid crystal molecules when the first and second substrates are interposed therebetween, and one of the polarized light beams whose optical axis is set in a predetermined direction. A liquid crystal display device comprising: a plate; and a second polarizing plate having an optical axis set to be orthogonal or parallel to the optical axis of the one polarizing plate. 3. The orientation film is subjected to a first orientation treatment in a first direction substantially parallel to a normal line of the smectic C phase layer, and a second orientation treatment is performed in a second direction opposite to the first direction. The liquid crystal display device according to claim 1, wherein the second alignment process is performed by superimposing the first alignment process on the first direction. 4. The liquid crystal display device according to claim 1, further comprising a second alignment film formed on the second electrode and the second substrate. .