JPH07311373A - Antiferroelectric liquid crystal element and its driving method - Google Patents

Abstract

PURPOSE:To display in good condition at a high contrast and to speed up writing of a screen even if an antiferroelectric liquid crystal material having-a small cone angle is used by using a specific cell constitution and driving method. CONSTITUTION:An antiferroelectric liquid crystal cell 12 formed by sandwiching antiferroelectric liquid crystals between a pair of substrates having at least one piece of scanning electrode and signal electrode respectively on their opposite surfaces is disposed between two sheets of such polarizing plates 11A and 11B of which the axes 13A, 13B of polarization intersect orthogonally with each other. The element is so constituted that the axes 13A, 13B of either of the polarizing plates 11A, 11B and the average major axis directions of the liquid crystal molecules of the second stable state where the molecule arrangement is stabilized by driving of the antiferroelectric liquid crystal molecules by positive voltage or the third stable state where the molecule arrangement is stabilized by driving of the antiferroelectric liquid crystal molecules by negative voltage attain nearly the same direction. As a result, the quantity of the transmitted light at the time of displaying black is made nearly equal and the quantity of the transmitted light at the time of displaying white is made larger.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an antiferroelectric liquid crystal element used in a liquid crystal display panel having a matrix of pixels having an antiferroelectric liquid crystal as a liquid crystal layer, a liquid crystal optical shutter array, and the like, and a driving method thereof. It is a thing.

[0002]

2. Description of the Related Art A liquid crystal panel using an antiferroelectric liquid crystal is
JP-A-2 of Nippon Denso Co., Ltd. and Showa Shell Sekiyu Co., Ltd.
Since the publication of 173724 discloses that it has a wide viewing angle, that it can respond at high speed, and that it has good multiplex characteristics, it has been actively researched.

FIG. 2 is a block diagram of a conventional antiferroelectric liquid crystal element when the antiferroelectric liquid crystal is used as a display. Two polarizing plates 11A and 11 matched to crossed Nicols
Between B, the liquid crystal cell 12 is placed such that the polarization axis of either one of the polarizing plates and the average major axis direction of the liquid crystal molecules when no voltage is applied are parallel to each other.

FIG. 3 shows the value of the applied voltage when a voltage is applied to the liquid crystal cell and the light passing through the liquid crystal display at the time when the antiferroelectric liquid crystal device is constructed as shown in FIG. It shows the transmittance of. When the applied voltage value is increased from the state where the applied voltage is 0 V (first stable state), the transmittance increases with it, and the transmittance saturates and becomes constant at a certain voltage or higher. This state is the second stable state. Next, when the voltage value is decreased, the transmittance starts to decrease below a certain voltage value, and when the voltage value becomes negative via the first stable state, the transmittance starts to increase again.
Then, when the voltage value is below a certain value (absolute value is above a certain value), the transmittance becomes constant again. This state is the third stable state. After that, if you decrease the absolute value of the applied voltage,
As with the positive voltage side, the first stable state is reached. That is, as shown in FIG. 3, in the case of the panel structure shown in FIG. 2, the antiferroelectric liquid crystal has a first stable state in which the transmittance is reduced and a positive voltage of a certain value or more is applied. A second stable state in which the transmittance is increased in some cases, and a third state in which the transmittance is increased when a negative voltage of a certain value or more is applied.
It has three stable states:

It is known that the molecules of the antiferroelectric liquid crystal have a multi-layered structure, and in the above-mentioned second or third stable state, the applied voltage and its polarity act on the dipole of the liquid crystal molecule. The liquid crystal molecules in all layers are arranged in the same direction. In both of these stable states, the liquid crystal molecules are tilted at mutually opposite angles with respect to the rubbing axis of the alignment film. Further, in the above-mentioned first stable state, the liquid crystal molecules are arranged in the same direction within the layer, and the layer is alternately arranged in the second and third layers.
It has a molecular configuration in the stable state of. The states other than the stable states are transition states between the stable states.

The conventional antiferroelectric liquid crystal element utilizes the above-mentioned three stable states. When no voltage is applied, the liquid crystal molecules are in the first stable state, light is not transmitted, and black display occurs,
When a voltage is applied to the liquid crystal cell, it becomes a second or third stable state depending on the polarity of the applied voltage, and the liquid crystal molecules are inclined at an angle with respect to this polarization axis, so that light transmission occurs. Will be displayed.

FIG. 4 is a diagram showing an example of the drive voltage waveform and the amount of transmitted light in the conventional driving method of the antiferroelectric liquid crystal device having the panel structure shown in FIG. It is composed of two scanning periods for writing one screen, and the respective scanning periods (first scanning period and second scanning period) have polarities symmetrical to each other with respect to 0 V. The status is used for display. The first stable state is reset in the first half of the selection period, and the reset state is held by the select pulse in the latter half of the selection period (black display) or switched to the second or third stable state (white display). Is selected.

[0008]

However, in the case of displaying with such a cell structure, the amount of light transmitted through the cell is an average of liquid crystal molecules in the second stable state and the third stable state. It depends on the angle (cone angle) formed by the major axis direction, and the light amount becomes the highest when this angle is 90 degrees as shown in FIG. However, since most typical antiferroelectric liquid crystal materials have a cone angle of 60 degrees or less, it is difficult to increase the amount of light transmitted through the cell when white display is performed. Was difficult to do. Also, from the second or third stable state to the first
Since the speed of switching to the stable state is slower than the response speed of switching from the first stable state to the second or third stable state, it is necessary to increase the pulse width of the reset pulse. As a result, the writing speed of the display screen has become slow.

Therefore, according to the present invention, the amount of transmitted light for white display is increased, that is, display with high contrast is performed even when the screen is written at high speed and an antiferroelectric liquid crystal material having a small cone angle which is currently available is used. It is an object of the present invention to provide an antiferroelectric liquid crystal device having a cell structure for performing the above and a driving method thereof.

[0010]

In order to achieve the above object, in an antiferroelectric liquid crystal device of the present invention, an antiferroelectric liquid crystal element is provided between a pair of substrates each having at least one scanning electrode and signal electrode on opposite surfaces. An antiferroelectric liquid crystal cell sandwiching a ferroelectric liquid crystal is provided between two polarizing plates whose polarization axes are orthogonal to each other, and one of the polarizing axes of the polarizing plate and the antiferroelectric liquid crystal molecule are A second stable state where the molecular arrangement is stabilized by being driven by a positive voltage or a third stable state where the molecular arrangement is stabilized by being driven by a negative voltage. The liquid crystal molecules are sandwiched so that the average long axis direction of the liquid crystal molecules in the state is almost the same direction.

In the antiferroelectric liquid crystal element,
The driving method is characterized in that display is performed using the second stable state and the third stable state without using the first stable state of the antiferroelectric liquid crystal described above.

The drive voltage waveform for displaying the antiferroelectric liquid crystal element has at least one scanning period, and the scanning period has at least a selection period and a non-selection period. The period is a period in which liquid crystal molecules are selected to switch to the second or third stable state, and the non-selection period is a period for holding the state selected in the selection period. Use the method.

In the above-described antiferroelectric liquid crystal device of the present invention, one of the polarization axes of the polarizing plate and the average long axis direction of the liquid crystal molecules in the second stable state are substantially in the same direction. In such a sandwiched configuration, during the selection period, at least the reset period in which the liquid crystal molecules are reset to the second stable state and the switching to the third stable state or the second stable state is performed. A driving method is used, which is characterized by being configured from a select period for selecting whether to hold.

On the contrary, in the above-described antiferroelectric liquid crystal device of the present invention, one of the polarization axes of the polarizing plate and the third
In the case where the liquid crystal molecules are sandwiched so that the average long-axis direction of the liquid crystal molecules in the stable state is substantially the same direction, the reset period resets at least the third stable state of the liquid crystal molecules during the selection period. The driving method is characterized by comprising a period and a select period for selecting whether to switch to the second stable state or hold the third stable state.

Further, in these driving methods, the driving method characterized in that the voltage value of the scanning side electrode in the non-selected period is 0V is used.

In the present invention, among the three stable states of the above-mentioned antiferroelectric liquid crystal molecules, the second stable state and the third stable state are used for display and the like, and the time-consuming first state is displayed. Since the switching to the stable state of is not used, the screen can be written at high speed.

Further, by using the antiferroelectric liquid crystal element of the present invention and the method of driving the same, the amount of transmitted light for white display can be increased even when an antiferroelectric liquid crystal material having a small cone angle which is currently available is used. That is, it is possible to perform display with high contrast.

In the antiferroelectric liquid crystal device of the present invention, the average major axis direction of the antiferroelectric liquid crystal molecules in the liquid crystal cell in the first stable state is almost the same as the rubbing direction of the alignment film. . Therefore, based on this rubbing direction and the cone angle of the antiferroelectric liquid crystal used, the direction of the polarization axis of the polarizing plate and the average long axis direction of the liquid crystal molecules in the second or third stable state are the same. An antiferroelectric liquid crystal device can be manufactured.

The antiferroelectric liquid crystal element of the present invention can be used in a matrix liquid crystal display panel having a plurality of scanning electrodes and signal electrodes as described above, but it can also be used in an optical shutter array of a liquid crystal printer or the like. it can.

[0020]

The function of the present invention will be further described. FIG. 1 is a block diagram of an antiferroelectric liquid crystal device of the present invention. As described above, the antiferroelectric liquid crystal has three stable states as shown in FIG. When the average long axis direction of the liquid crystal molecules in the third stable state among the three stable states is made parallel to any of the polarization axes of the polarizing plate as shown in FIG. Is in the third stable state,
Since the long axis direction of the liquid crystal molecules and the polarization axis are parallel to each other and the vibration direction of the transmitted light passing through the liquid crystal cell does not change, no light is transmitted and black display can be performed. On the contrary, when the liquid crystal molecules are in the second stable state, that is, when the liquid crystal molecules are inclined by the cone angle with respect to this polarization axis, birefringence occurs and light is transmitted.

When the average major axis direction of the liquid crystal molecules in the second stable state is set to be parallel to one of the polarization axes of the polarizing plate, when the liquid crystal molecules are in the second stable state. , The long axis direction of this liquid crystal molecule is parallel to the polarization axis,
Since the vibration direction of the transmitted light passing through the liquid crystal cell does not change, the light does not pass therethrough and black display can be performed. On the contrary, when the liquid crystal molecules are in the third stable state, that is, when the liquid crystal molecules are inclined by the cone angle with respect to this polarization axis, birefringence occurs and light is transmitted.

In an antiferroelectric liquid crystal device having a structure in which an antiferroelectric liquid crystal cell is sandwiched between two polarizing plates whose polarization axes are orthogonal to each other, an average major axis direction of liquid crystal molecules in a stable state Is parallel to either polarization axis,
The amount of transmitted light is minimum, and conversely, when the average major axis direction of the liquid crystal molecules in the stable state is 45 degrees with the polarization axis, the amount of transmitted light is maximum.

The cone angle (the angle formed by the average long axis directions of the liquid crystal molecules in the second stable state and the third stable state) is 6
In the antiferroelectric liquid crystal of less than 0 degree, the present invention and the prior art (the antiferroelectricity in which one of the polarization axes of the polarizing plate is aligned with the average long axis direction of the liquid crystal molecules in the first stable state). Comparing the antiferroelectric liquid crystal element (liquid crystal element), the average major axis direction of the liquid crystal molecules in the stable state where the amount of transmitted light is maximum is closer to the direction in which the present invention is closer to 45 degrees with the polarization axis, The amount of light is large.

In the antiferroelectric liquid crystal device of the present invention,
Since the polarization axis of any one of the polarizing plates and the average long axis direction of the liquid crystal molecules in the second or third stable state are sandwiched so as to be substantially in the same direction, the cone angle described above is used. When an antiferroelectric liquid crystal with a temperature of 60 degrees or less is used, the amount of transmitted light becomes minimum when the liquid crystal molecule is in the second or third stable state among the three stable states described above.
When in the other stable state, the amount of transmitted light is maximum.

From the above, using the antiferroelectric liquid crystal device of the present invention, the angle (cone angle) formed by the average long axis directions of the liquid crystal molecules in the second stable state and the third stable state is 45 degrees. In this case, the difference in transmitted light amount between black display and white display can be maximized.

Most of the currently available antiferroelectric liquid crystal materials have almost no angle of 60 degrees or more between the second stable state and the third stable state. It can be easily obtained.

From the above, the anti-ferroelectric liquid crystal element of the present invention has the same amount of transmitted light in black display and the transmitted light amount in white display as compared with the conventional anti-ferroelectric liquid crystal element. It is possible to increase the size and display with high contrast can be performed.

Further, even in driving with such a cell structure, it is necessary to hold the amount of transmitted light selected in the non-selection period. In the antiferroelectric liquid crystal, when the applied voltage is set to 0V when the liquid crystal molecules are located in the second or third stable state, the liquid crystal molecules try to return to the first stable state, but this response speed is very high. Some liquid crystal materials are very slow, and some materials have a length of 10 ms to 100 ms. Further, in the conventional technique shown in FIG. 2, white is displayed in the second or third stable state, and black is displayed in the first stable state. Therefore, if the applied voltage for holding the white display is set to 0V, white is displayed. However, in the present invention, the apparent response speed is further slowed down because the present invention tries to return to halftone rather than white, as shown in FIG. This second or third
If the response speed for returning from the stable state to the first stable state is slow, the non-selection period in the drive waveform can be lengthened and the number of scanning lines can be increased. In other words, in the present invention, even in the case of display with a large number of scanning lines, the applied voltage in the non-selected period can be set to 0 V, that is, the amount of transmitted light can be held by the characteristics of the liquid crystal itself. It is not necessary to apply a holding voltage as in the conventional case during the non-selection period, which enables display with less flicker.

The display panel using the antiferroelectric liquid crystal element has been mainly described above, but the same effect can be obtained in the case of an optical shutter array or the like.

[0030]

Embodiments of the present invention will now be described in detail with reference to the drawings.

Example 1 FIG. 5 is a cell configuration diagram of the liquid crystal panel used in this example. The liquid crystal panel used in this embodiment is composed of a pair of glass substrates 53a and 53b having an antiferroelectric liquid crystal layer 56 having a thickness of about 2μ. Electrodes 54a and 54b are formed on the opposite surface of the glass substrate, and polymer alignment films 55a and 55b are applied thereon,
The rubbing process is done. Further, the first polarizing plate 51a is provided outside the one glass substrate so that the major axis direction of the liquid crystal molecules in the third stable state and the polarizing axis of the polarizing plate are parallel to each other. A second polarizing plate 51b is provided outside the other glass substrate so that the polarizing axis of the first polarizing plate 51a differs from that of the first polarizing plate 51a by 90 °. Further, in this example, an antiferroelectric liquid crystal having a threshold voltage of 30 V and a cone angle of 45 degrees was used.

FIG. 6 is a diagram showing the drive voltage waveform of the first embodiment of the present invention and the change in the amount of transmitted light in accordance therewith. The drive voltage waveform is composed of a combination of the scan electrode waveform and the signal electrode waveform, and a composite voltage waveform that is the difference between the two is applied to the pixel. The drive waveform used in this example is a pulse having a four-phase selection period, and the pulse width is set to 50 μs. The time of the non-selection period is about 10 ms. The selection period consists of two periods, a reset period and a selection period,
The first three pulses are the reset period and the second half pulse is the select period. In the reset period of the selection period, the liquid crystal molecules are temporarily brought into the third stable state, and depending on the voltage value of the select period, the state is held (black display) or switched to the second stable state (white display). To do.

The scan electrode waveforms are set such that the voltage value of the first phase and the voltage value of the fourth phase, which are applied during the selection period, are set to 25V, and the voltage values of the second phase and the third phase are set to -25V, respectively. The voltage value applied during the period was 0V. In the case of white display (ON state), the signal electrode waveform is applied with a pulse in which the first layer and the third phase are set to 5V, the second phase and the fourth phase are set to -5V, and the black display (OFF state) is applied. ) Is performed, the first phase and the third phase are set to -5V, and the second phase and the fourth phase are set to 5V.
A pulse set to V was applied. As the signal electrode waveform applied during the non-selection period, an arbitrary signal electrode waveform is applied depending on the display state of other pixels of the liquid crystal display. Due to the scanning electrode waveform and the signal electrode waveform, a composite voltage waveform, which is the difference between the two, is applied to the liquid crystal in the liquid crystal panel, and the change in the transmitted light amount at that time is measured, and the result is shown as the transmitted light amount in FIG. .

In this embodiment, white display (ON state)
When performing, the combined voltage waveform becomes −30V in the third phase, is temporarily reset to the third stable state, is set to + 30V in the fourth phase (select period), and is switched to the second stable state. Is displayed in white. Conversely, when black display (OFF state) is performed, the combined voltage waveform is the first
It becomes + 30V in phase and enters the second stable state.
It becomes −30V in phase and is reset to the third stable state. Then, the fourth phase (selection period) is set to +20 V, the third stable state is held, and black display is performed.

As the display contrast, the ratio of the amount of transmitted light in the white display (second stable state) to the amount of transmitted light in the black display (third stable state) was calculated.
Met.

When the display contrast was similarly measured using antiferroelectric liquid crystals having cone angles of 35 degrees and 55 degrees, the display contrasts were 30 and 32, respectively.

(Comparative Example 1) A pair of polarizing plates is set such that one polarization axis thereof is parallel to the major axis direction of liquid crystal molecules in the first stable state. Driving was performed using a conventional liquid crystal panel different from the liquid crystal panel used in Example 1 and using the conventional driving method shown in FIG. Using the same antiferroelectric liquid crystal as that used in Example 1, the amount of transmitted light during white display (second or third stable state) versus the amount of transmitted light during black display (first stable state) The ratio was obtained and the display contrast was measured. The display contrast obtained was 13.

When the display contrast was similarly measured using antiferroelectric liquid crystals having cone angles of 35 degrees and 55 degrees, the display contrasts were 11 and 22, respectively.

(Embodiment 2) FIG. 7 is a diagram showing a drive voltage waveform according to a second embodiment of the present invention and a change in the amount of transmitted light according to the drive voltage waveform. In this example, the same liquid crystal panel as in Example 1 was used. Further, in this example, the same liquid crystal as in Example 1 was used. The drive voltage waveform is composed of a combination of the scan electrode waveform and the signal electrode waveform, and a composite voltage waveform that is the difference between the two is applied to the pixel. The drive waveform used in this embodiment is composed of two scanning periods, and each scanning period is composed of a selection period and a non-selection period. The drive waveform used in the present invention is a pulse having a selection period of two phases, and the pulse width is set to 50 μs. The time of the non-selection period is about 10 ms. In the driving method using the driving voltage waveform of the present embodiment, when white display (ON state) is performed, black display (OFF state) is performed during the selection period of the second scanning period.
When performing, the setting is performed in the selection period of the first scanning period. That is, when performing white display (ON state),
In the selection period of the first scanning period, the applied voltage value is smaller than the voltage value for transitioning from the second or third stable state to another state, so that switching to another stable state is not performed and the previous state (ON state in FIG. 7) is held, and this state is also held during the subsequent non-selection period. Then, the white display (ON state) is selected by applying a positive pulse having a sufficient voltage value for switching to the second stable state in the latter half pulse of the selection period of the second scanning period, and the subsequent non-display is selected. This state is maintained during the selection period. Also, black display (O
In the FF state), by applying a negative pulse having a voltage value sufficient for switching to the third stable state in the latter half pulse of the selection period of the first scanning period, black display (OFF (State) is selected, and this state is maintained during the subsequent non-selection period. Then, in the selection period of the second scanning period, the applied voltage value is smaller than the voltage value required to shift from the third stable state to another stable state, and this state is held, and the subsequent non-selection period is performed. But it keeps this state.

The scan electrode waveform used in the driving method of this embodiment is set such that the voltage value of the first phase applied in the selection period of the first scan period is 25V and the voltage value of the second phase is -25V.
The voltage value applied in the non-selection period is 0 V, and the voltage value in the first phase applied in the selection period in the second scanning period is -25.
The voltage value of V and the second phase was set to 25V, and the voltage value applied during the non-selection period was set to 0V. The signal electrode waveform was set to 10 V for the first layer and -10 V for the second phase when white display (ON state) was performed. When displaying black (OFF state), the first phase is -10 V and the second phase is 1
It was set to 0V. Further, as the signal electrode waveform applied during the non-selection period, an arbitrary signal voltage waveform is applied depending on the display state of other pixels of the liquid crystal display. A composite voltage waveform, which is the difference between the two, is applied to the liquid crystal in the liquid crystal panel by the scanning electrode waveform and the signal electrode waveform, and the change in the transmitted light amount at that time is measured. The result is shown in FIG. 7 as the transmitted light amount. .

As the display contrast, the ratio of the transmitted light amount in the white display (second stable state) to the transmitted light amount in the black display (third stable state) was obtained, and as a result, the cone angle was 35 degrees. When using 45 ° and 55 ° antiferroelectric liquid crystals, the values were 27, 31, and 29, respectively.

Table 1 shows the measurement results of the display contrast when using the antiferroelectric liquid crystal of each cone angle in Examples 1 and 2 and Comparative Example 1 shown above. As a result, it can be seen that the display contrasts of both examples are considerably larger than those of the comparative example in any antiferroelectric liquid crystal having each cone angle, which is good. That is, with the antiferroelectric liquid crystal element and driving method of the present invention, display with high contrast could be performed. Moreover, since the display is performed using the second stable state and the third stable state instead of using the first stable state of the antiferroelectric liquid crystal described above, it is possible to write the screen at high speed. It was

[0043]

[Table 1]

In Examples 1 and 2, the major axis direction of the liquid crystal molecules in the third stable state and the polarization axis of the polarizing plate are parallel to each other on the outside of one glass substrate. A liquid crystal panel in which one polarizing plate is arranged is used, but a liquid crystal panel in which the polarizing axis of either polarizing plate is arranged to be parallel to the major axis direction of liquid crystal molecules in the second stable state is used. However, the same result can be obtained.

[0045]

As described in the above embodiments, by using the cell structure and the driving method of the present invention, even when an antiferroelectric liquid crystal material having a small cone angle is used, a high contrast and a good display are obtained. It can be performed. In addition, the screen can be written at high speed.

[Brief description of drawings]

FIG. 1 is a diagram showing a panel structure of an antiferroelectric liquid crystal element of the present invention.

FIG. 2 is a diagram showing a panel structure of a conventional antiferroelectric liquid crystal element.

FIG. 3 is a diagram showing a change in transmittance when a voltage is applied to a conventional antiferroelectric liquid crystal element.

FIG. 4 is a diagram showing a conventional method for driving an antiferroelectric liquid crystal element.

FIG. 5 is a configuration diagram of an antiferroelectric liquid crystal cell used in an example of the present invention.

FIG. 6 is a diagram showing a method for driving the antiferroelectric liquid crystal element used in Example 1 of the present invention.

FIG. 7 is a diagram showing a method for driving an antiferroelectric liquid crystal element used in Example 2 of the present invention.

[Explanation of symbols]

11A Polarizing plate A 11B Polarizing plate B 12 Liquid crystal cell 13A Polarization axis A 13B Polarization axis B 14 Arrow indicating the average major axis direction of liquid crystal molecules in the first stable state 15 Liquid crystal molecule in the second stable state 16 indicating the average long axis direction of the arrow 16 indicating the average long axis direction of the liquid crystal molecules in the third stable state 51a, 51b polarizing plates 52a, 52b sealing materials 53a, 53b glass substrates 54a, 54b electrodes 55a, 55b Polymer alignment film 56 Antiferroelectric liquid crystal layer

Claims (5)

[Claims] 1. An antiferroelectric liquid crystal cell in which an antiferroelectric liquid crystal is sandwiched between a pair of substrates each having at least one scanning electrode and signal electrode on opposite surfaces, and their polarization axes are orthogonal to each other. In an anti-ferroelectric liquid crystal device having a configuration sandwiched between two such polarizing plates, the anti-ferroelectric liquid crystal element is driven by a positive voltage on either polarization axis of the polarizing plate and the anti-ferroelectric liquid crystal. The second stable state where the molecular arrangement of the ferroelectric liquid crystal is stable, or the third stable state where the molecular arrangement of the anti-ferroelectric liquid crystal is stabilized by driving the anti-ferroelectric liquid crystal by a negative voltage. 2. An antiferroelectric liquid crystal device, characterized in that the average long axis direction of the antiferroelectric liquid crystal molecules in the stable state is substantially the same direction. 2. The method for driving an antiferroelectric liquid crystal element according to claim 1, wherein display is performed by using the second stable state and the third stable state. 3. The drive voltage waveform of the anti-ferroelectric liquid crystal element according to claim 1 has at least one scanning period, and at least the selection period and the non-selection period exist in the scanning period, and the selection period is The antiferroelectric liquid crystal is a period for selecting whether to switch to the second stable state or the third stable state, and the non-selection period is for maintaining the state selected in the selection period. The method for driving an antiferroelectric liquid crystal element according to claim 1, wherein the period is a period. 4. The selection period comprises at least a reset period for resetting to the second or third stable state and a select period for selecting the third or second stable state. The driving method according to claim 3, wherein 5. The voltage value of the scanning-side electrode in the non-selected period is 0 V, according to claim 3 or 4.
The driving method described.