JPH0758371B2 - Liquid crystal element driving method - Google Patents

Description

The present invention relates to a method for driving a liquid crystal element, particularly a method for driving a multiplex of an electro-optical element using a ferroelectric liquid crystal.

[Conventional technology]

As described in JP-A-56-107216, a chiral smectic C phase or a chiral smectic H
It is known that an electro-optical element using a ferroelectric liquid crystal exhibiting a phase responds to an applied voltage at an extremely high speed and has a memory property. Applications for capacitive displays, high-speed electronic shutters, polarizers, etc. are expected.

Conventionally, as a driving method of such a ferroelectric liquid crystal element, as described in JP-A-58-179890,
A driving method is known in which a pulse voltage that determines the light transmission state of a liquid crystal element is applied in a predetermined cycle, and the average value of the voltage applied in this predetermined cycle is set to zero to prevent deterioration of the ferroelectric liquid crystal. . However, the specific driving method disclosed in Japanese Patent Laid-Open No. 179890/1983 is a static driving method, and no multiplex driving method optimal for driving a large capacity element is disclosed. It is known that the ferroelectric liquid crystal element has a so-called pulse width dependency, that is, the threshold voltage changes depending on the pulse width of the applied voltage pulse. The driving method described in Japanese Laid-Open Patent Publication No. 179890 does not consider this pulse width dependency at all, and it is difficult to actually drive it.

Therefore, we have proposed Japanese Patent Application No. 59-119680 (Japanese Patent Laid-Open No. 60-2631).
No. 24) and Japanese Patent Application No. 60-177818 (Japanese Patent Application Laid-Open No. 61-
In the Japanese Laid-Open Patent Publication No. 55630), the above-mentioned pulse width dependency was considered, but a practical multiplex driving method was proposed.

[Problems to be solved by the invention]

However, in this driving method, since no special consideration is given to the average value of the voltage applied to the ferroelectric liquid crystal, the average value of the applied voltage may be biased to either positive or negative, It has a drawback of promoting the deterioration of the ferroelectric liquid crystal and shortening the life of the liquid crystal element.

By the way, Figures 2 and 3 of British Patent Application Publication No. 2146473
The figure discloses a drive waveform in which the average value of the voltage applied to the liquid crystal is not biased to be positive or negative. Therefore, the pulse width of the data signal is set to 2 times the pulse width of the scanning signal.
Since it is set more than twice, there is a fatal drawback that the light transmission property of the liquid crystal is rather deteriorated in return.

The present invention solves the above-mentioned problems, and an object thereof is to apply a liquid crystal to a liquid crystal during a selection period in order to prevent deterioration of a liquid crystal having a memory property such as a ferroelectric liquid crystal. It is an object of the present invention to provide a driving method of a liquid crystal element, which can prevent deterioration of the liquid crystal by setting the average value of the voltage applied to the liquid crystal to be zero every certain period without significantly restricting the voltage pulse.

Another object of the present invention is to provide a method of driving a liquid crystal element, which can improve the contrast ratio while preventing deterioration of the liquid crystal.

[Means for Solving the Problems and Their Actions] The present invention is a line-sequential scanning of a liquid crystal element in which a liquid crystal having a memory property is sandwiched between a substrate having a scanning electrode group and a substrate having a signal electrode group. In the method for driving a liquid crystal element by multiplex driving, a scanning signal having a selection potential in the selection period and a scanning signal having a non-selection potential in the non-selection period is supplied to the scanning electrode group, and the signal electrode group is provided for each selection period. A data signal for selecting a display state is supplied, and the molecules of the liquid crystal are aligned in a predetermined alignment direction during the selection period or in a non-selection period immediately before the selection period, which is at least 1 of a saturation value of the liquid crystal display element A number of voltage pulses are applied to the liquid crystal, and then a voltage pulse for placing the molecules of the liquid crystal in a predetermined alignment direction corresponding to the display state is applied to the liquid crystal within the selection period. When the intermediate potential of the data signal is used as a reference potential, the scan signal includes a plurality of voltage pulses that are positive and negative with respect to the reference potential, and includes the selection period and the non-selection period that follows. Within a predetermined period, the integrated value of the positive voltage pulse and the integrated value of the negative voltage pulse are different, and
The polarities of the positive and negative voltage pulses are inverted in two consecutive predetermined periods, and the data signal is composed of a plurality of voltage pulses that are positive and negative with respect to the reference potential,
The integral value of the positive voltage pulse and the integral value of the negative voltage pulse are set equal to each other within the predetermined period, and the average value of the voltage applied to the liquid crystal is set to zero within the two predetermined periods. It is characterized by

According to the present invention, in one predetermined period including the selection period and the subsequent non-selection period, for example, a period called one frame or one field, the positive and negative voltage pulses of the scanning signal waveform with respect to the reference potential are applied. For example, even if the crest value is different, the positive and negative polarities of the scanning signal with respect to the reference potential are inverted in the next frame or field period, so that the voltage is applied to the liquid crystal in two consecutive frame periods or two consecutive field periods. It is possible to prevent the liquid crystal element from deteriorating because the average value of the voltages applied becomes zero.

As described in JP-A-58-179890, the molecules of the ferroelectric liquid crystal are arranged in a spiral form with an angle of θ with respect to the spiral axis when no electric field is applied. However, as shown in FIG. 1A, when an electric field −E having a negative polarity is applied, for example, the molecules 1 of the ferroelectric liquid crystal are aligned with the spiral axis 2 on a plane perpendicular to the direction of the electric field −E. Are arranged in a certain direction with an angle θ. Further, when the polarity of the electric field is reversed, as shown in FIG. 1 (b), the spiral axes 2 are arranged at an angle θ in a direction symmetrical to the direction of FIG. 1 (a). At this time, as shown in FIGS. 1 (a) and (b),
Two polarizing plates are provided above and below the ferroelectric liquid crystal, and the polarization axis direction of the upper polarization plate is 3 and the polarization axis direction of the lower polarization plate is 4
When the molecules of the ferroelectric liquid crystal are aligned in the direction of FIG. 1 (a), the amount of light transmission becomes the smallest when the molecules of the ferroelectric liquid crystal are aligned so as to be in the direction of FIG. 1 (b). In the case of arranging in the direction, the amount of transmitted light is the largest. In addition, such an alignment state of the molecules of the ferroelectric liquid crystal remains stable until a voltage higher than the threshold voltage of the opposite polarity is applied next. This is one of the characteristics of the ferroelectric liquid crystal which is said to have a memory property.

In the present invention, the polarity of the voltage for arranging the molecules of the ferroelectric liquid crystal in the direction as shown in FIG. 1 (a) is negative (-), and the voltage for arranging the molecules in the direction as shown in FIG. 1 (b) is The polarity is defined as positive (+), the alignment direction of molecules and the direction of the polarization axis of the polarizing plate have a relationship as shown in FIG. 1 (a), and the state in which the amount of light transmission is the smallest is turned off. The state (or simply off) has the relationship shown in FIG. 1 (b), and the state with the largest amount of light and the amount of light transmission is on (or simply on).
It is defined as

Of course, the relationship between the alignment direction of molecules and the direction of the polarization axis is
If the figures (a) and (b) are reversed, the light and transmission amount will be maximum when a positive voltage is applied, and the light and transmission amount will be minimum when a negative voltage is applied. It can be driven by substantially the same driving method only by reversing the relationship of the combination of ON and OFF states, and is included in the scope of the present invention.

〔Example〕

FIG. 2A is a cross-sectional view showing an example of a liquid crystal element used in each example of the present invention described below. A plurality of transparent scanning electrodes 13 and signal electrodes 14 made of indium oxide or tin oxide are formed on the inner surfaces of the transparent substrates 11 and 12 made of glass or plastic that face each other. After providing an insulating layer made of silicon oxide or the like on these electrodes as necessary, an alignment film 15 made of polyimide, nylon or the like is provided, and the surface of the alignment film of at least one substrate is rubbed to obtain a ferroelectric liquid crystal. 16 was oriented in a given direction. 19 is a sealing agent made of an epoxy adhesive. Polarizing plates 17 and 18 were adjacent to the outer surfaces of the pair of substrates 11 and 12 on which the electrodes were not formed. At this time, the polarization axes of the polarizing plate 17 and the polarizing plate 18 are substantially orthogonal to each other, and ferroelectric liquid crystal molecules when a voltage having a negative polarity or a saturation value or more is applied to the ferroelectric liquid crystal 16. The direction of the polarization axis of the polarizing plate was set so that the arrangement direction of (1) was parallel to the direction of the polarization axis of either one of the polarizing plates.

The gap between the substrates, that is, the thickness of the liquid crystal layer is approximately 1.3 μm.
m, the ferroelectric liquid crystal used is P-tetradecyloxybenzylidene-P'-amino- (2-methyl) -butyl-
(Α-cyano) -cinnamate (TDOBAMBCC).
This liquid crystal has a threshold voltage when the pulse width is 200 μsec.
The saturation voltage was 6.5 V, the saturation voltage was 8 V, the threshold voltage was 4.2 V and the saturation voltage was 6.3 V when the pulse width was 400 μsec. This value was almost the same even when the polarity was reversed.

As shown in FIG. 2B, the scanning electrodes 13 and the signal electrodes 14 are formed in stripes and are formed so as to be orthogonal to each other. A pixel is a portion where the scanning electrode and the signal electrode overlap each other in plan view. Incidentally, FIG. 2 (b)
In order to make the following description easy to understand, typical types of ON / OFF patterns are shown, and the number of scan electrodes Xn is 6, and the number of signal electrodes Yn is 3, but the present invention is of course the present invention. However, the number of electrodes is not limited to this, and the number of electrodes may be determined according to the required number of pixels. In FIG. 2 (b), the shaded pixels are in the off state, and the other pixels are in the on state.

An example of a specific driving method for driving this liquid crystal element will be shown below.

Example 1 FIG. 3 shows drive waveforms and light transmission characteristics in this example applied to each pixel on the scanning electrode X ₁ for turning on and off as shown in FIG. 2 (b). Show. In order to make it easier to understand the change in the light transmission characteristics, the on / off states of all pixels were reversed in the next frame cycle.

In FIG. 3, t ₁₃ indicates the first frame period and t ₂₃ indicates the next frame period. Also, t ₁₁ and t ₂₁ are selection periods,
t ₁₂ and t ₂₂ indicate the non-selection period, respectively. Furthermore t ₁₄ ,
_{t 15, t 16, t 17} , t 24, t 25, t 26 and t ₂₇ are respectively 200μsec
It shows the pulse width of V, which shows the peak value V ₁ is 6V, V ₂ is 3V
Is.

± V ₁ is applied to the scanning electrode X ₁ during the selection period t ₁₁ (t ₂₁ ) and 0 V is applied during the non-selection period t ₁₂ (t ₂₂ ), and the signal electrodes Y ₁ , Y ₂ and Y ₃ are When you want to turn on the pixel, the pulse width is 200 at the peak value V _2.
When the pulse of μsec is applied in the order of positive, negative, positive, negative, and when it is desired to turn it off, it is applied in the order of negative, positive, negative, positive, and the voltage pulse applied to each pixel is (+ V ₁ −
V ₂ ), (-V ₁ + V ₂ ), (-V ₁ -V ₂ ), (+ V ₁ + V ₂ ) in that order, and when off (+ V ₁ + V ₂ ), (-V ₁ -V _2). ),
(-V ₁ + V _2), made in the order of (+ V ₁ -V _2). At this time,
Since (+ V ₁ −V ₂ ) and (−V ₁ + V ₂ ) are smaller than the threshold voltage of the liquid crystal, the liquid crystal does not respond and is equal to or higher than the saturation value (+ V ₁ + V ₂ ) and (−V ₁ + V ₂ ). Responds to V ₁ −V ₂ ).
However, since the ferroelectric liquid crystal responds at high speed and has a memory property, it is apparently recognized that the liquid crystal is turned on or off depending on the polarity of the pulse having the saturation value or more applied at the end of the selection period. To be done.

In the non-selection period, (+ V ₁ −V ₂ ) and (−V ₁ + V ₂ ) pulses are applied, and the maximum pulse width is 400 μsec.
Since the peak value is smaller than the threshold voltage of the liquid crystal at 400 μsec, it has almost no effect on the light transmission characteristics. The contrast ratio of on and off is 18: 1 for the pixel (X ₁ , Y ₁ ).
(X ₁ Y ₂₎ at _{16: 1, (X 1 Y} 3) at 18: 1, on a substantially constant contrast ratio regardless off pattern is obtained.

The driving method in this embodiment is such that the liquid crystal has a selection period t
Within ₁₁ (t ₂₁ ), the peak value is at least the saturation value of the liquid crystal,
Positive and negative voltage pulses having a pulse width are applied, and the positive and negative voltage pulses have the same peak value and pulse width, and are turned on or off in the order of applying a positive or negative voltage pulse having a saturation value or more. Since the number of positive and negative voltage pulses selected is equal and the positive and negative voltage pulses having the peak value and pulse width below the threshold value are applied during the non-selection period t ₁₂ (t ₂₂ ), As shown in FIG. 3, the average value of the DC component is zero, and there is no DC component at all. Therefore, the liquid crystal element never deteriorated.

FIG. 4 is a circuit block diagram of an example of a concrete circuit for realizing the drive waveform shown in FIG. 111 is a transmission gate, 112 is a flip-flop, and 113 is a liquid crystal element. d, h, e, f, g, j, k, l are transmission gates 1
11, the scanning electrode signal Vt and the signal electrode signal Vd are generated and applied to the liquid crystal element 113. Further, ± V ₁ and zero V, ± V ₂ are power supply voltages of the scan electrodes and the signal electrodes. FIG. 5 shows the scan electrode signal Vt and the signal electrode signal Vd of the circuit shown in FIG.
Is the signal at each point for making.

Example 2 FIG. 6 shows driving waveforms applied to the scan electrode X ₁ and the signal electrode Y ₁ for turning on and off as shown in FIG. 2 (b) and the pixel (X ₁ Y ₁ ) 2 shows the light transmission characteristics thereof. In order to facilitate understanding of the change in light transmission characteristics, in the next frame period t _23, one, obtained by inverting the OFF state.

In FIG. 6, t _{11 to} t ₂₇ all indicate the same as in FIG. 3, and the peak values V ₁ , V ₂ , V ₃ , V ₄ , V ₅ , and V ₆ are 8 respectively.
V, 6V, 5V, 3V, 2V, 0V. Vm represents the intermediate potential of the voltage pulse applied to the signal electrode, which is 4V in this case.

The difference from the first embodiment is that the voltage levels of the scan electrodes and the signal electrodes are made the same in order to reduce the voltage applied to the scan electrodes.

The scan electrode X ₁ is applied in the order of V ₁ , V ₆ , V ₆ , and V ₁ with a pulse width of 200 μsec in the selection period t ₁₁ (t ₂₁ ) and the non-selection period t ₁₂ (t
₂₂ ) ignites V ₂ and V ₅ in the order shown in the figure. To the signal electrode Y ₁ , if you want to turn on the pixel, apply a pulse width of 200 msec in the order of V ₄ , V ₃ , V ₁ , and V ₆ , and if you want to turn it off, apply in the reverse order. To do. Pixels at this time (X ₁ Y ₁ )
The voltage applied to (V ₁ −V ₄ ), (V ₆ −
V ₃ ), (V ₆ −V ₁ ), (V ₁ −V ₆ ), in that order (V ₁ −V ₆ ), (V ₆ −V ₁ ), (V ₆ −V ₃ ), The order is (V ₁ −V ₄ ), and a pulse with a saturation value or higher turns on or off depending on the polarity of the pulse applied later. Note that (V ₁ −V ₄ ) and (V ₆ −V ₃ ) applied during the selection period are + 5V and −5V, respectively, which is larger than the liquid crystal threshold value at a pulse width of 400 μsec. 200 μsec width
Therefore, it is smaller than the threshold value at 200 μsec, and the liquid crystal does not respond. In addition, (V ₅ −V ₆ ) and (V ₂
-V ₁ ) pulse is applied, the pulse width may be 400 μsec depending on the on / off pattern, but the peak value is 40
Since it is smaller than the threshold value of the liquid crystal at 0 μsec, it hardly affects the light transmission characteristics.

The driving method according to this example provided the same favorable contrast ratio as that of Example 1.

The driving method in this embodiment is such that the liquid crystal has a selection period t
Within ₁₁ (t ₂₁ ), the peak value is at least the saturation value of the liquid crystal,
Positive and negative voltage pulses having a pulse width are applied, and the positive and negative voltage pulses have the same peak value and pulse width, and are turned on or off in the order of applying a positive or negative voltage pulse having a saturation value or more. selected, also further voltage pulses of the positive and negative are equal in number, the non-selection period t ₁₂ (t ₂₂₎ is, since the positive having the following peak value and pulse width threshold, a negative voltage pulse is applied The average value of the applied voltage was zero regardless of the on / off pattern, and the liquid crystal element did not deteriorate.

FIG. 7 is a block diagram showing an example of a concrete circuit for realizing the drive waveform shown in FIG. , Signal
The transmission gate 111 is selected, and the scanning electrode waveform at the time of selecting and the non-selected scanning electrode waveform are selected by the scanning electrode data of. On the other hand, the signal electrode waveform depends on the signal of,
Select 1 and select the ON waveform and OFF waveform of the signal electrode data to create the signal electrode waveform and the liquid crystal element 11
Applied to 3. Further, V ₁ , V ₂ , V ₃ , V ₄ , V ₅ , and V ₆ are power supply voltages of the scan electrodes and the signal electrodes. FIG. 8 shows signals at various points in the circuit shown in FIG.

Example 3 FIG. 9 shows a drive waveform applied to each pixel on the scan electrode X ₁ for turning on and off as shown in FIG. 2 (b) and a light transmission characteristic. In order to facilitate understanding of the change in light transmission characteristics, in the next frame period t _23, one, obtained by inverting the OFF state.

In FIG. 9, all of t _{11 to} t ₂₇ indicate the same as in FIG. 3, and the peak value V ₁ is 9V and V ₂ is 4V.

The difference from the first and second embodiments is that the pulse width of the pulse applied in the non-selection period is not less than the saturation value applied to select the on / off state of the liquid crystal in order to improve the contrast ratio. The point is that it is not larger than.

To the scan electrode X ₁ , ± V ₁ is applied during the selection period t ₁₁ (t ₂₁ ), 0V is applied during the non-selection period, and 0V is desired to be turned on when the pixel is to be turned on and the signal electrode is turned off. If the first 400μsec
Is applied for 0 V, and for the next 400 μsec, it is applied for 200 μsec each in the order of −V ₂ , + V ₂ . At this time, the voltage pulse applied to each pixel is in the order of (+ V ₁ ), (−V ₁ ), (−V ₁ ), (+ V ₁ ) when on, and (+ V ₁ ) when off. , (−V ₁ ), (−V,
The order is + V ₂ ) and (+ V ₁ −V ₂ ). Since (−V ₁ , + V ₂ ) and (+ V ₁ −V ₂ ) are smaller than the threshold value of the liquid crystal when the pulse width is 200 μsec, the liquid crystal does not respond and is turned on during the selection period of t ₁₁ . It repeatedly turns off and turns on in response to the last applied + V ₁ at t ₁₇ , and during the selection period of t ₂₁ , it turns on at t ₂₄ and then responds to −V ₁ applied at t _25. It is turned off. Although the 0V or pulse width 200 .mu.sec + V ₂ or -V ₂ is applied to the non-selection period, V ₂
Is smaller than the liquid crystal threshold value, and therefore has almost no effect on the light transmission characteristics.

The contrast ratio obtained by this embodiment is the pixel (X
₁ Y ₁₎ in 24: 1, (X ₁ Y ₂₎ at 22: 1, with 20 (X ₁ Y _3): 1, even better contrast ratio than Examples 1 and 2 were obtained.

The driving method in this embodiment is such that the liquid crystal has a selection period t
Within ₁₁ (t ₂₁ ), the peak value is at least the saturation value of the liquid crystal,
Positive and negative voltage pulses having a pulse width are applied, and the positive and negative voltage pulses have the same peak value and pulse width, and are turned on or off in the order of applying a positive or negative voltage pulse having a saturation value or more. Since the number of positive and negative voltage pulses selected is equal and the positive and negative voltage pulses having the peak value and pulse width below the threshold value are applied during the non-selection period t ₁₂ (t ₂₂ ), Regardless of the on / off pattern, the average value applied to the liquid crystal element was zero, and the liquid crystal element did not deteriorate.

FIG. 10 is a circuit block diagram of an example of a concrete circuit for realizing the drive waveform shown in FIG. (A), (c),
A signal for selecting the transmission gate 111 is created by the signal of (i), the transmission gate 111 is selected by these signals, and the scanning electrode signal Vt and the signal electrode signal Vd are created and applied to the liquid crystal element 113. It Also, ± V ₁ ,
± V ₂ , 0V is the power supply voltage of the scan electrode and the signal electrode. First
FIG. 1 shows signals at various points in the circuit shown in FIG.

Example 4 FIG. 12 shows driving waveforms applied to the scan electrode X ₁ and the signal electrode Y ₁ for turning on and off as shown in FIG. 2 (b) and the pixel (X ₁ Y ₁ ). 2 shows the light transmission characteristics thereof. In order to facilitate understanding of the change in light transmission characteristics, in the next frame period t ₂₃ on, by inverting the OFF state.

In FIG. 12, all of t _{11 to} t ₂₇ indicate the same as in FIG. 3, and the peak values V ₁ , V ₂ , V ₃ , V ₄ , V ₅ , and V ₆ are 1 respectively.
It is 0V, 8V, 6V, 4V, 2V, 0V. Vm represents the intermediate potential of the voltage pulse applied to the signal electrode, which is 5V in this case.

The difference from the third embodiment is that the voltage levels of the scan electrodes and the signal electrodes are made common in order to reduce the voltage applied to the scan electrodes.

During the selection period t ₁₁ (t ₂₁ ), V ₁ and V ₆ are applied to scan electrode X ₁ as V ₁ , V
_6, in the order of V _6, V _1, the non-selection period t ₁₂ (t ₂₂₎ is, V ₂ and V ₅ and V _2,
V _5, V _5, is applied in the order of V _2, the signal electrodes Y _1, if you want to turn on the pixel, in the order of _{V 5, V 2, V 2} , V 5, if you want to turn off, V ₅ , V ₂ , V ₃ , V ₄ are applied in this order. Both have a pulse width of 2
It is 00 μsec. At this time, the voltage pulse applied to the pixel (X ₁ Y ₁ ) has the same waveform as that of the driving method of the third embodiment as shown in FIG. 9 except that the peak value is different. That is (V ₁ −
V ₅ ) and (V ₅ −V ₂ ) are + 8V and −8V, respectively, above the liquid crystal saturation value, and (V ₁ −V ₄ ) and (V ₆ −V ₃ ) are + 6V and −6V, respectively, with a pulse width of 200 μsec. , Which is smaller than the threshold value of, and (V ₂ −V ₃ ) and (V ₅ −V ₄ ) are + 2V and −2V, respectively, which are sufficiently smaller than the threshold value of the liquid crystal. Therefore, the liquid crystal element responded in the same manner as in Example 3, and similarly a good contrast ratio was obtained.

FIG. 13 is a block diagram of an example of a specific circuit that realizes the drive waveform shown in FIG. , The transmission gate 111 is selected, and the scanning electrode data is selected by selecting the scanning electrode waveform at the time of selection and the non-selected scanning electrode waveform. On the other hand, the signal electrode waveform depends on the signal of
Select the ON waveform and OFF waveform with the signal electrode data of to create the signal electrode waveform, and
Applied to 3. Further, V ₁ , V ₂ , V ₃ , V ₄ , V ₅ , and V ₆ are power supply voltages of the scan electrodes and the signal electrodes. FIG. 14 shows signals at various points in the circuit shown in FIG.

Fifth Embodiment A fifteenth embodiment shows a drive waveform applied to each pixel on the scan electrode X ₁ for turning on and off as shown in FIG. 2B and a light transmission characteristic. In order to facilitate understanding of the change in light transmission characteristics, in the next frame period t _23, one, obtained by inverting the OFF state.

In FIG. 15, t ₁₃ indicates the first frame period and t ₂₃ indicates the next frame period. Also, t ₁₁ and t ₂₁ are the selection period, t
₁₂ and t ₂₂ indicate the non-selection period, and further the non-selection period t ₁₂
And t ₂₂ are divided into two periods, a first non-selection period t ₁₆ and t ₂₆ and a second non-selection period t ₁₅ and t ₂₅ provided immediately before the next selection period, that is, at the end of the frame period. ing. t ₀₅ indicates the second non-selection period immediately before the first frame period t ₁₃ . t ₁₄ indicates a pulse width of 200 μsec.

The peak value V ₁ is 11V, V ₂ is 6V, and V ₃ is 2.5V.

For the scan electrode X ₁ , the selection period t ₁₁ (t ₂₁ ) is ± V _2, the first non-selection period t ₁₆ (t ₂₆ ) is 0 V, and the second non-selection period t ₀₅ (t ₁₅ , t
₂₅ ) applies ± V ₁ to the signal electrodes Y ₁ , Y ₂ and Y ₃ if the pixels are to be turned on, then ± V ₃ in the order of positive and negative. Apply in positive order. At this time, each pixel has
The second non-selection period t immediately before the selection period t ₁₁ (t ₂₁ ).
_{At 05} (t ₁₅ , t ₂₅ ), both are (+ V-
V ₃ ) and (−V ₁ + V ₃ ) or (+ V ₁ + V ₃ ) and (−V ₁ −V ₃ ) are applied, and during the selection period t ₁₁ (t ₂₁ ), when (−V ₁ + V ₃₎ ) And (+ V−V ₃ ) are off, (−V ₂ + V ₃ ) and (+ V ₂ −V ₃ ) are applied, and the on / off pattern is applied in the first non-selection period t ₁₆ (t ₂₆ ). Therefore, ± V ₃ is applied with a pulse width of 200 μsec or 400 μsec. Since ± V ₃ is a value smaller than the threshold value at 400 μsec, even if the pulse width becomes 400 μsec, it hardly affects the light transmission characteristics.

The driving method of the present embodiment is such that the pixel is turned on immediately before the selection period and then turned off, and a pulse having a positive saturation value or more is applied within the selection period immediately after that, or a pulse having a pulse value equal to or less than the threshold value is applied. By selecting whether to invert to the on state or hold the off state as it is by applying the voltage, it is possible to halve the time of the selection period as compared with the driving method of Examples 1 to 4. This is an effective driving method when higher speed driving is required or when the number of scan electrodes is increased.

Further, the peak value of the pulse applied in the second non-selection period t ₀₅ (t ₁₅ , t ₂₅ ) differs depending on the ON and OFF patterns, but since both are above the saturation value, the light transmission amount is does not change. Further, in the present embodiment, since a pulse having a value equal to or higher than the saturation value of the liquid crystal is applied to turn on and off in the non-selection period,
Although the contrast ratio is slightly lowered, the lowering ratio of the contrast ratio is reduced as the number of scanning electrodes is increased, and a good contrast ratio can be obtained. In the case of this embodiment, the pixel (X ₁
A contrast ratio of 17: 1 for (Y ₁ ), 16: 1 for (X ₁ Y ₂ ) and 17: 1 for (X ₁ Y ₃ ) was obtained. Also in this embodiment, the average value of the voltage applied to the liquid crystal was zero, and the liquid crystal element was not deteriorated.

In the present embodiment, the second non-selection period is provided at the end of the frame cycle, that is, immediately before the next selection period. However, when it is applied to a display device, if it is within a time range in which human eyes cannot identify it. , It does not have to be just before the selection period.

FIG. 16 is a circuit block diagram showing an example of a concrete circuit for realizing the drive waveform shown in FIG. 15, when the transmission gate 111 is selected by the signal of and the scanning electrode data of is selected. A scan electrode waveform and a non-selected scan electrode waveform of 0 V are selected to create a scan electrode waveform. On the other hand, the signal electrode waveform depends on the signal of
111 is selected, and an ON waveform and an OFF waveform are selected with the signal electrode data of to create a signal electrode waveform, and the signal electrode waveform is applied to the liquid crystal element 113. Further, ± V ₁ , ± V ₂ , ± V ₃ , 0V are power supply voltages of the scan electrodes and the signal electrodes. FIG. 17 shows signals at various points in the circuit shown in FIG.

Example 6 FIG. 18, FIG. 2 (b) to indicate such on the driving waveform applied to the scan electrodes X _1, X ₂ and the signal electrodes Y ₁ to the OFF state, the pixel (X ₁ The light transmission characteristics of Y ₁ ) are shown. Note that for clarity the change in light transmission characteristics, in the next frame period t ₂₃ on, by inverting the OFF state.

In FIG. 18, t _{05 to} t ₂₆ are the same as those in FIG. 15, and t ′ ₀₅ and t ′ ₁₅ are the second non-selection period in the scan electrode X ₂ , t ′ ₁₁ and t ′. ₂₁ also select period, t _'16 the first non-selection period, t' ₁₂ represents a non-selection period of the frame period including the first and second non-selection period.

The peak values V ₁ , V ₂ , V ₅ and V ₆ are 12V, 10V, 2V and 0V, respectively, and V ₃
And V ₈ is 8V and V ₄ and V ₉ are 4V. Vm represents the intermediate potential of the voltage pulse applied to the signal electrode, in this case 6V
Is.

The difference from the fifth embodiment is that the voltage levels of the scan electrodes and the signal electrodes are made common in order to reduce the voltage applied to the scan electrodes.

The scanning electrode X ₁ has V ₄ and V for the selection period t ₁₁ (t ₂₁ ).
₃ , V ₂ and V ₅ in the first non-selection period t ₁₆ (t ₂₆ )
During the second non-selection period t ₀₅ (t ₁₅ , t ₂₅ ), V ₁ and V ₆ are applied. When the scan electrode X ₁ is an odd-numbered scan electrode, X ₂ which is an even-numbered scan electrode has X _{1 as} shown in FIG.
A pulse train whose phase is opposite to that of is applied. This is the scan electrode
When the pixel on X ₁ is in the selection period t ₁₁ (t ₂₁ ), scan electrode X ₂
The upper pixel is a second non-selection period t _'05 (t' ₁₅₎ in order to apply a saturation value or more pulses for turning on and off the pixel at this time. That is, in this embodiment, it is necessary to alternately apply pulses of opposite phases to each scan electrode. Further, as a result, the pulse applied to the signal electrode Y ₁ needs to have different waveforms for the pixel on the pixel and the pulse on the odd electrode for turning on and off the pixel. There is. That is, when turning on the pixels on the odd-numbered scan electrodes (for example, X ₁ ), V ₁ and V ₆ are set in order of V ₁ and V ₆ , and when turning off, V ₈ and V ₉ are set to V ₈ and V ₉ To turn on the pixels on even-numbered scan electrodes (for example, X ₂ ), apply V ₈ and V ₉ to V ₉ and V
_To turn off in the order of ₈ , V ₁ and V ₆ are applied in the order of V ₆ and V ₁ . At this time, the pulse applied to the pixel (X ₁ Y ₁ ) is different from that of the fifth embodiment only in the peak value, but the substantially same pulse is applied. That is, when turned on, the negative in the selection period t ₁₁ (V ₄ -V ₁₎ and (V ₃ -V _6), the positive saturation value or more pulses are applied, the case of off, the selection period t ₂₁ ( V ₄
Pulses with values smaller than the negative and positive thresholds of −V ₈ ) and (V ₃ −V ₉ ) are applied. In addition, the second immediately before the selection period
In the selection period t ₀₅ (t ₁₅ , t ₂₅ ), (V ₁ −V ₄ ) and (V ₆ −
V ₈ ) or (V ₁ −V ₆ ) and (V ₆ −V ₁ ) are applied with a pulse with a saturation value or more in the order of positive and negative, and the pixel is turned on and then turned off. In the next selection period, it is selected whether to turn on or keep the off state as it is.

In the first selection period t ₁₆ (t ₂₆ ), the pulse width is 200 μsec depending on the ON / OFF pattern as in the fifth embodiment.
Or 400 μsec (V ₅ −V ₆ ) and (V ₂ −V ₁ ) or (V ₂ −V ₈ ) and (V ₅ −V ₉ ) pulse width 400 μs
A pulse with a value smaller than the threshold at ec is applied.

Like the fifth embodiment, the driving method of the present embodiment is an effective driving method when higher speed driving is required or when the number of scan electrodes is increased, and the same contrast ratio as that of the fifth embodiment was obtained. .

FIG. 19 is a block diagram showing an example of a concrete circuit for realizing the drive waveform shown in FIG. The transmission gate 111 is selected by the signals of, and the scanning electrode waveform at the time of selection and the non-selected scanning electrode waveform are selected by the scanning electrode data of, and the scanning electrode waveform is created. Note that the even-numbered scan electrode selection waveforms are shown. On the other hand, the signal electrode waveform is
The transmission gate 111 is selected by the signal of, and the ON waveform and the OFF waveform of the signal electrode data are selected to form a signal electrode waveform, which is applied to the liquid crystal element 113. Further, V ₁ , V ₂ , V ₃ , V ₄ , V ₅ , V ₆ , V ₈ and V ₉ are power supply voltages of the scan electrodes and the signal electrodes. FIG. 20 shows signals at various points in the circuit shown in FIG.

Example 7 FIG. 21 shows a drive waveform applied to each pixel on the scanning electrode X ₁ for turning on and off as shown in FIG. 2 (b) and a light transmission characteristic. In order to facilitate understanding of the change in light transmission characteristics, in the next frame period t _23, one, obtained by inverting the OFF state.

In FIG. 21, t _{05 to} t ₂₆ show the same as in FIG. 15, and the peak value V ₁ is 8V and V ₂ is 4V.

The difference from the fifth and sixth embodiments is that the pulse width of the pulse applied in the non-selection period is larger than the pulse of the saturation value or more applied to turn on and off the liquid crystal in order to improve the contrast ratio. There is a point that I did not become.

For the scan electrode X ₁ , the selection period t ₁₁ (t ₂₁ ) is ± V _1, the first non-selection period t ₁₆ (t ₂₆ ) is 0 V, and the second non-selection period t ₀₅ (t ₁₅ , t
₂₅ ) applies ± V ₁ in the reverse order of the selection period, and applies 0V to the signal electrodes Y ₁ , Y ₂ and Y ₃ to turn on the pixel and ± V ₂ to turn off the pixel. Is applied in the order of negative and positive. At this time, in each pixel, in the second non-selection period t ₀₅ (t ₁₅ , t ₂₅ ) immediately before the selection period t ₁₁ (t ₂₁ ), ± V ₁ or (+ V ₁ + V ₂ ) which is equal to or higher than the saturation value is generated. ) And (−V ₁ −V ₂ ) are applied, and in the selection period t ₁₁ (t ₂₁ ), ± V ₁ when on and (−V ₁ + V ₂ ) and (+ V ₁ −V ₂ ) when off. Is applied, and during the first selection period t ₁₆ (t ₂₆ ), according to the on / off pattern,
(+ V ₁ -V ₂₎ and (-V ₁ + V ₂₎ or 0V is applied. As described above, during the non-selection period, a pulse having a pulse width larger than 200 μsec is not applied, and the influence on the light transmission characteristics is further reduced.

In the driving method of the present embodiment, as in the fifth and sixth embodiments, the pixel is turned on immediately before the selection period and then turned off, and a pulse having a positive saturation value or more is applied within the selection period immediately thereafter. In addition, since it is selected whether to invert to the on state or to keep the off state as it is by applying a pulse below the threshold value, the time of the selection period is longer than that of the driving method of the first to fourth embodiments. Can be halved, which is an effective driving method when higher speed driving is required or when the number of scan electrodes is increased.

In the case of this embodiment, the pixel (X ₁ Y ₁ ) is 22: 1 (X ₁ Y ₂ ) 21:
A contrast ratio of 20: 1 was obtained with 1, (X ₁ Y ₃ ). Also in this embodiment, the average value of the voltage applied to the liquid crystal was zero, and the liquid crystal element was not deteriorated.

Although the second non-selection period is provided at the end of the frame cycle, that is, immediately before the next selection period also in this embodiment, if it is applied to a display device, if it is within a time range in which human eyes cannot identify it. , It does not have to be just before the selection period.

FIG. 22 is a circuit block diagram showing an example of a concrete circuit for realizing the drive waveform shown in FIG. 21, in which the transmission gate 111 is selected by the signal of, and the selection is made by the scanning electrode data of. The scan electrode waveform and the non-selected scan electrode waveform of 0 V are selected to create the scan electrode waveform. On the other hand, the signal electrode waveform depends on the signal of
111 is selected, and an ON waveform and an OFF waveform are selected with the signal electrode data of to create a signal electrode waveform, and the signal electrode waveform is applied to the liquid crystal element 113. Further, ± V ₁ , ± V ₂ , 0V are power supply voltages of the scan electrodes and the signal electrodes. FIG. 23 shows signals at various points in the circuit shown in FIG.

Example 8 FIG. 24, FIG. 2 (b) to indicate such on the driving waveform applied to the scan electrodes X _1, X ₂ and the signal electrodes Y ₁ to the OFF state, the pixel (X ₁ The light transmission characteristics of Y ₁ ) are shown. In order to facilitate understanding of the change in light transmission characteristics, in the next frame period t _23, one, obtained by inverting the OFF state.

In Figure 24, both t ₀₅ ~t ₂₆ and t _'05 ~t' ₂₁ shows the same thing as FIG. 18.

Crest values V ₁ , V ₂ , V ₃ , V ₄ , V ₅ , V ₆ are 10V, 9V, 7V, 3V, 1V, 0 respectively
V. Vm represents the intermediate potential of the voltage pulse applied to the signal electrode, which in this case is 5V.

The difference from the seventh embodiment is that the voltage levels of the scan electrodes and the signal electrodes are made common in order to reduce the voltage applied to the scan electrodes.

V ₄ and V ₃ are applied to the scan electrode X ₁ during the selection period t ₁₁ (t ₂₁ ).
V ₂ and V ₅ are applied during the first non-selection period t ₁₆ (t ₂₆ ), and V ₁ and V ₆ are applied during the second non-selection period t ₀₅ (t ₁₅ , t ₂₅ ).
When the scan electrode X ₁ is an odd-numbered scan electrode, a pulse train having a phase opposite to that of X ₁ is applied to the even-numbered scan electrode X ₂ , as shown in FIG. This is because when the pixel on the scan electrode X ₁ is in the selection period t ₁₁ (t ₂₁ ), the pixel on the scan electrode X ₂ is in the second non-selection period t ′ ₂₅ (t ′ ₁₅ ). This is because a pulse having a saturation value or more for turning the pixel on and off is sometimes applied. That is, in this embodiment, it is necessary to alternately apply pulses of opposite phases to each scan electrode. As a result, the pulse applied to the signal electrode Y ₁ is
The pulse for turning on the pixel and the pulse for turning off the pixel need to have different waveforms for the pixels on the odd-numbered scan electrodes and the pixels on the even-numbered scan electrodes. That is, when turning on the pixels on the odd-numbered scan electrodes (for example, X ₁ ),
The V ₁ and V ₆ in the order of V _1, V _6, the case of off-V ₂ and V
₅ is applied in order of V ₂ and V ₅ , and even-numbered scan electrodes (for example,
When the pixel on X ₂ ) is turned on, V ₂ and V ₅ are applied in the order of V ₅ and V ₂ , and when turned off, V ₁ and V ₆ are applied in the order of V ₆ and V ₁ . Pulses applied to the case the pixel (X ₁ Y ₁₎ in the case of on, the selection period t ₁₁ (V ₄ -V ₁₎ and (V ₃ -
When pulses above the negative and positive saturation values of (V ₆ ) are applied and turned off, during the selection period t ₂₁ , the negative and positive threshold values of (V ₄ −V ₂ ) and (V ₃ −V ₅ ) are exceeded. A small value pulse is applied.
In the second selection period t ₀₅ (t ₁₅ , t ₂₅ ) immediately before the selection period, (V ₁ −V ₅ ) and (V ₆ −V ₂ ) or (V ₁ −V ₆ ) and (V ₆ − V ₁₎ either the saturation value or more pulses positive, is applied to the negative order, turned off after time has decreased and phlegm on state pixel, in the next selection period, or inverted to turn on, as it is turned off You have the choice to keep it.

During the first selection period t ₁₆ (t ₂₆ ), depending on the ON / OFF pattern, 0 V or (V ₅ −
Positive V ₆₎ and (V ₂ -V ₁ sufficiently smaller than the liquid crystal threshold), a negative pulse is applied.

The driving method of this embodiment is also an effective driving method when higher speed driving is required or when the number of scanning electrodes is increased, as in the fifth to seventh embodiments, and the same contrast ratio as that of the seventh embodiment is obtained. Was given.

FIG. 25 is a block diagram showing an example of a concrete circuit for realizing the drive waveform shown in FIG. The transmission gate 111 is selected by the signals of, and the scanning electrode waveform at the time of selection and the non-selected scanning electrode waveform are selected by the scanning electrode data of, and the scanning electrode waveform is created. Note that the even-numbered scan electrode selection waveforms are shown. On the other hand, the signal electrode waveform is
The transmission gate 111 is selected by the signal of, and the ON waveform and the OFF waveform of the signal electrode data are selected to form a signal electrode waveform, which is applied to the liquid crystal element 113. Further, V ₁ , V ₂ , V ₃ , V ₄ , and V ₅ are power supply voltages of the scan electrodes and the signal electrodes. FIG. 26 shows signals at various points in the circuit shown in FIG.

Example 9 FIG. 27 shows a drive waveform applied to each pixel on the scanning electrode X ₁ for turning on and off as shown in FIG. 2 (b) and a light transmission characteristic. In order to facilitate understanding of the change in light transmission characteristics, in the next frame period t _23, one, obtained by inverting the OFF state.

In FIG. 27, t ₁₃ indicates the first frame period and t ₂₃ indicates the next frame period. Also, t ₁₁ and t ₂₁ are the selection period, t
₁₂ and t ₂₂ indicate a non-selection period, and t ₁₄ indicates a pulse width of 200 μsec. Further, t ₁₅ and t ₂₅ indicate periods for applying the average value correction pulse provided immediately before the next selection period, that is, at the end of the frame period. In this case, 200
It is a period of μsec.

The peak value V ₁ is 10V, V ₂ is 8V, V ₃ and V ₄ are 2V.

To the scan electrode X ₁ , + V ₁ and −V ₂ are applied in the order t ₁₁ (t ₂₁ ), 0 V is applied during the non-selection period t ₁₂ (t ₂₂ ), and the last period t ₁₅ (t ₂₅ ) applies −V ₃ as a correction pulse. For the signal electrodes Y ₁ , Y ₂ and Y ₃ , ± V ₄ is positive and negative in order to turn on the pixel, and negative and negative to turn off.
Apply in positive order. At this time, if each pixel is on,
Smaller pulses than the threshold after the saturation value or more pulses (+ V ₁ -V ₄₎ is applied (-V ₂ + V ₄₎ is applied, either in the case of off-saturation value or more pulses (+ V ₁ + V ₄ ) and (-V ₂ -V ₄₎ positive, is applied to the negative order. Non-selection period
t ₁₂ (t ₂₂ ) is ± V ₄ of 200 depending on the ON / OFF pattern.
It is applied with a pulse width of μsec or 400 μsec, but only the last period t ₁₅ (t ₂₅ ) of the frame period, the correction pulse −V ₃ is added, so (−V ₃ −V ₄ ) or (−V 3 ₃ +
V ₄₎ In other words -4V or 0V is applied.

In this embodiment, after the first pulse having a positive polarity saturation value or more for turning on the pixel is applied at the beginning of the selection period, the second pulse having the opposite polarity and different peak value is applied. ON or OFF is selected depending on whether the pulse No. 2 is below the threshold value or above the saturation value. At this time, the difference between the peak value of the first pulse and the peak value of the second pulse is equalized regardless of whether it is on or off, and this difference is t
The average value of the voltage applied within one frame period is made zero by performing the correction in the period of ₁₅ (t ₂₅ ).

In the present embodiment, the pulse width of the correction pulse and the pulse width of the first pulse and the second pulse are made equal, but the present invention is not limited to this, and | V ₁ · t
₁ | − | V ₂ · t ₂ | ＝ | V ₃ · t ₃ | (where t ₁ , t ₂ and t ₃ indicate the pulse width of each pulse) It is sufficient to set the high value and the pulse width.

The driving method of the present embodiment is also the same as in the fifth to eighth embodiments.
Since the time of the selection period can be halved as compared with the driving methods of 4 to 4, this is an effective driving method when higher speed driving is required or when the number of scan electrodes is increased. Further, unlike the driving methods of Examples 5 to 8, since the pixel does not turn on and off during the non-selection period, a liquid crystal shutter in which a change in the amount of transmitted light in a very short time causes a quality problem, etc. It is an effective driving method when applied to.

In the case of this embodiment, the pixel (X ₁ Y ₁ ) is 20: 1 and the pixel (X ₁ Y ₂ ) is 17:
A contrast ratio of 20: 1 was obtained with 1, (X ₁ Y ₃ ). Further, in this embodiment, the correction pulse is applied at the end of the frame period, that is, immediately before the next selection period. However, since the correction pulse has almost no effect on the light transmission characteristics, the non-selection period It may be applied at any timing within the range.

FIG. 28 is a block diagram showing an example of a concrete circuit for realizing the drive waveform shown in FIG. The scan electrode data signal 121 is transferred to the shift register 115 by the scan electrode shift clock signal 120 to the scan electrode, and a waveform of d in the selection period, 0 V in the non-selection period, and a voltage for correcting the DC component immediately before the selection rule are applied. It switches to output the scan electrode waveform. On the other hand, for the signal electrode, the signal electrode data signal 117 is transferred to the shift register 114 by the signal electrode shift clock 118, and when the data for one scanning line is transferred, the latch signal 119 is latched 116, and the output of the transmission gate 111. To output on or off (waveform of b or c). V ₁ , -V ₂ ,-
V ₃ and ± V ₄ are drive voltages for the scan electrodes and the signal electrodes.

FIG. 29 is a timing chart showing signal waveforms of the circuit shown in FIG. 28.

Example 10 FIG. 30 shows driving waveforms applied to the scan electrode X ₁ and the signal electrode Y ₁ for turning on and off as shown in FIG. 2 (b) and the pixel (X ₁ Y ₁ ). 2 shows the light transmission characteristics thereof. In order to facilitate understanding of the change in light transmission characteristics, in the next frame period t ₂₃ on, by inverting the OFF state.

In FIG. 30, all of t _{11 to} t ₂₅ are the same as in FIG. 27.

Peak values V ₁ , V ₂ , V ₃ ,, V ₄ ,, V ₅ ,, V ₅ , V ₇ are 12V, 10V, 8V, 6 respectively.
They are V, 4V, 2V and 0V. Vm represents the intermediate potential of the voltage pulse applied to the signal electrode, which in this case is 5V.

The difference from the ninth embodiment is that the voltage levels of the scan electrodes and the signal electrodes are made common in order to reduce the voltage applied to the scan electrodes.

The scanning electrode X ₁ has a selection period t ₁₁ (t ₂₁ ) in the order of V ₁ and V ₇ ,
During the non-selection period t ₁₂ (t ₂₂ ), V ₅ and V ₃ are applied in this order, and t ₁₅ (t
Period of ₂₅₎ applies a V ₄ as a correction pulse. When the pixel is to be turned on, V ₅ and V ₄ are applied to the signal electrode Y ₁ in order, and when the pixel is to be turned off, V ₇ and V ₂ are applied in order. At this time, each pixel has a pulse (V ₁
-V ₅ ) is applied and then a pulse (V ₇
-V ₄ ) is applied, and when it is off, pulses (V ₁ -V ₇ ) and (V ₇ -V ₂ ) above the saturation value are applied in the order shown in the figure. In the non-selection period t ₁₂ (t ₂₂ ), (V ₆ −V ₇ ) and (V ₃ −V ₂ ) are 200 μsec depending on the ON / OFF pattern.
Or, it is applied with a pulse width of 400 μsec, but since the correction pulse V ₄ is applied only during the last period t ₁₅ (t ₂₅ ) of the frame period, (V ₄ −V ₂ ) or (V ₄ −V ₄ ) That is, −
4V or 0V is applied.

Like the ninth embodiment, the present invention corrects the difference between the peak values of the positive and negative pulses applied during the selection period in the period of t ₁₅ (t ₂₅ ) and averages the voltage applied within one frame period. The value is set to zero.

Similar to the ninth embodiment, the driving method of the present embodiment is also an effective driving method when applied to a liquid crystal shutter or the like, and the same contrast ratio as that of the ninth embodiment was obtained.

FIG. 31 is a circuit block diagram showing an example of a concrete circuit for realizing the drive waveforms shown in FIG. Signal of
The transmission gate 111 is selected, and the selected scan electrode waveform and the non-selected scan electrode waveform in the scan electrode data of are selected to generate the scan electrode waveform. On the other hand, the signal electrode waveform is applied to the liquid crystal element 113 by selecting the transmission gate 111 by the signal and selecting the on waveform of the signal electrode data and the off waveform of the signal electrode data. Further, V ₁ , V ₂ , V ₃ , V ₄ , V ₅ , V ₆ , and V ₇ are power supply voltages of the scan electrodes and the signal electrodes. FIG. 32 shows signals at various points in the circuit shown in FIG.

Example 11 FIG. 33 shows the drive waveform applied to each pixel on the scan electrode X ₁ for turning on and off as shown in FIG. 2 (b) and the light transmission characteristics. In order to facilitate understanding of the change in light transmission characteristics, in the next frame period t _23, one, obtained by inverting the OFF state.

In FIG. 33, t _{11 to} t ₂₅ show the same as in FIG. 27, and the peak value V ₁ is 8 V, V ₂ is 6 V, V ₃ and V ₄ are 2 V.
Is.

The difference from Examples 9 and 10 is that the pulse width of the pulse applied in the non-selection period is larger than that of the saturation value or more applied to turn on and off the liquid crystal in order to improve the contrast ratio. This is the point that I tried not to.

To the scan electrode X ₁ , 0 V is applied to the scanning electrode X ₁ in the order of ± V ₁ and −V _{2 for} the selection period t ₁₁ (t ₂₁ ), and 0 V for the non-selection period t ₁₂ (t ₂₂ ), and for the period of t ₁₅ (t ₂₅ ). Apply −V ₃ as a correction pulse. Signal electrode
The _{Y 1, Y 2, Y 3} , if it is desired to turn on the pixel 0V, if you want to turn off applies the ± V ₄ negative, the positive sequence. At this time, when the pixel is on, the pulse + V ₁ of the saturation value or more is applied, and then the pulse −V ₂ smaller than the threshold value is applied, and when the pixel is off, the pulse of the saturation value or more is applied. (+ V ₁ +
V _4), (- applied in the order of V ₂ -V _4). Non-selection period
t ₁₂ (t ₂₂ ) is the pulse width depending on the ON / OFF pattern.
A 200 μsec pulse ± V ₄ or 0 V is applied, but since the correction pulse −V ₃ is added only during the last period t ₁₅ (t ₂₅ ) of the frame period, (−V ₃ −V ₄ ) or − V ₃ is applied.

Also in this embodiment, after the first pulse having a positive polarity saturation value or more for turning on the pixel is applied at the beginning of the selection period, the second pulse having the opposite polarity and different peak value is applied. ON or OFF is selected depending on whether the pulse No. 2 is below the threshold value or above the saturation value. At this time, the difference between the peak value of the first pulse and the peak value of the second pulse is equalized regardless of whether it is on or off, and this difference is t
The average value of the voltage applied within one frame period is made zero by performing the correction in the period of ₁₅ (t ₂₅ ).

In the present embodiment, the pulse width of the correction pulse and the pulse width of the first pulse and the second pulse are made equal, but the present invention is not limited to this, and | V ₁ · t
₁ | − | V ₂ · t ₂ | ＝ | V ₃ · t ₃ | (where t ₁ , t ₂ and t ₃ indicate the pulse width of each pulse) It is sufficient to set the high value and the pulse width.

In the driving method of the present embodiment as well, as in the ninth and tenth embodiments, the selection period can be halved compared to the driving methods of the first to fourth embodiments. Therefore, when higher speed driving is required or scanning is performed. This is an effective driving method when the number of electrodes is increased. Further, unlike the driving methods of Examples 5 to 8, since the pixel does not turn on and off during the non-selection period, a liquid crystal shutter in which a change in the amount of transmitted light in a very short time causes a quality problem, etc. It is an effective driving method when applied to.

In the case of this embodiment, the pixel (X ₁ Y ₁ ) is 24: 1, and (X ₁ Y ₂ ) is 23:
A contrast ratio of 23: 1 was obtained with 1, (X ₁ Y ₃ ). Also in the case of the present embodiment, the timing of applying the correction pulse is not limited to immediately before the selection period.

FIG. 34 is a circuit block diagram showing an example of a concrete circuit for realizing the drive waveform shown in FIG. The scan electrode data signal 121 and the scan electrode shift clock signal 1 are supplied to the scan electrodes.
The waveform is transferred to the shift register 115 at 20 and the waveform of d is selected in the selection period, 0 V in the non-selection period, and the voltage for correcting the DC component immediately before the selection period is switched to output the scan electrode waveform. On the other hand, to the signal electrode, the signal electrode data signal 117 is transferred to the shift register 114 by the signal electrode shift clock 118, and when the data for one scanning line is transferred, the latch signal 119 is used to latch 116.
The transmission gate 111 is switched by the output to output ON or OFF (waveform of b or c). V ₁ ,
_{-V 2, -V 3, ± V} 4 is a drive voltage of the scanning electrodes and signal electrodes.

FIG. 35 is a timing chart showing signal waveforms of the circuit shown in FIG.

Example 12 FIG. 36 shows driving waveforms applied to the scanning electrode X ₁ and the signal electrode Y ₁ for turning on and off as shown in FIG. 2 (b) and the pixel (X ₁ Y ₁ ). 2 shows the light transmission characteristics thereof. In order to facilitate understanding of the change in light transmission characteristics, in the next frame period t ₂₃ on, by inverting the OFF state.

In FIG. 36, all of t _{11 to} t ₂₅ are the same as in FIG. 27.

The peak values V ₁ , V ₂ , V ₃ ,, V ₄ , V ₆ , V ₇ are 10V, 8V, 6V, 4V, 2 respectively.
It is V, 0V. Vm represents the intermediate potential of the voltage pulse applied to the signal electrode, which in this case is 4V.

The difference from the eleventh embodiment is that the voltage levels of the scan electrodes and the signal electrodes are made common in order to reduce the voltage applied to the scan electrodes.

The scanning electrode X ₁ is applied with V ₁ and V _{7 in} the order of selection period t ₁₁ (t ₂₁ ) and V ₅ and V ₃ in the non-selection period t ₁₂ (t ₂₂ ) in order of t ₁₅ (t _15).
During the period of (t ₂₅ ), V ₄ is applied as a correction pulse.
To the signal electrode Y ₁ , V ₆ and V ₃ are applied in order when the pixel is to be turned on, and V ₇ and V ₂ are applied in order when the pixel is to be turned off. At this time, each pixel has a pulse (V ₁
-V ₃ ) is applied and then a pulse (V ₇
-V ₃ ) is applied, and when it is off, pulses (V ₁ -V ₇ ) and (V ₇ -V ₂ ) each having a saturation value or more are applied in the order shown in the figure. In the non-selection period t ₁₂ (t ₂₂ ), (V ₆ −V ₇ ) and (V ₃ −V ₂ ) or 0 V is applied depending on the ON / OFF pattern, but the last period t of the frame period is t ₁₅ (t
₂₅ ), the correction pulse V ₃ is added, so (V ₄ −
V ₂ ) or (V ₄ −V ₃ ) is applied.

Also in the present embodiment, as in the eleventh embodiment, the difference between the peak values of the positive and negative pulses applied in the selection period is corrected in the period of t ₁₅ (t ₂₅ ) and the voltage applied in one frame period is The average value is set to zero.

Like the eleventh embodiment, the driving method of the present embodiment is also an effective driving method when applied to a liquid crystal shutter or the like.
A contrast ratio similar to 11 was obtained.

FIG. 37 is a circuit block diagram showing an example of a concrete circuit for realizing the drive waveform shown in FIG. Signal of
The transmission gate 111 is selected, and the selected scan electrode waveform and the non-selected scan electrode waveform in the scan electrode data of are selected to generate the scan electrode waveform. On the other hand, the signal electrode waveform is applied to the liquid crystal element 113 by selecting the transmission gate 111 by the signal and selecting the on waveform of the signal electrode data and the off waveform of the signal electrode data. Further, V ₁ , V ₂ , V ₃ , V ₄ , V ₆ , and V ₇ are power supply voltages of the scan electrodes and the signal electrodes. FIG. 38 shows signals at various points in the circuit shown in FIG.

Example 13 FIG. 39 shows drive waveforms applied to the scan electrode X ₁ and the signal electrode Y ₁ for turning on and off as shown in FIG. 2 (b) and the pixel (X ₁ Y ₁ ). 2 shows the light transmission characteristics thereof. In order to facilitate understanding of the change in light transmission characteristics, obtained by inverting the following off state in the frame period t _23.

In FIG. 39, t ₁₃ shows the first frame period, t ₂₃ shows the next frame period, t ₁₁ and t ₂₁ show the selection period, and t ₁₂ and t ₂₂ show the non-selection period. Further, t ₁₄ indicates a pulse width of 200 μsec.

The peak value V ₁ is 30V and V ₂ is 12V.

The feature of this embodiment is that the frequency is 10 KHz during the non-selection period.
It is to improve the contrast ratio by applying a high-frequency AC pulse to improve the memory property of the liquid crystal element.

The scan electrode X ₁ is applied with 0 V during the selection period t ₁₁ (t ₂₁ ) and an AC pulse of ± V ₁ during the non-selection period t ₁₂ (t ₂₂ ), and the signal electrode Y ₁
, ± V ₂ is applied in the order of positive and negative when the pixel is to be turned on, and in order of negative and positive when the pixel is to be turned off.

At this time, the pulses applied to the pixel (X ₁ Y ₁ ) are applied in the order of ± V _{2 in} the order of negative and positive when on, and in the order of positive and negative when off, and positive in the non-selection period. AC pulse with a peak value of (+ V ₁ + V ₂ ) and a negative peak value of (-V ₁ + V ₂ ) and a positive peak value of (+ V ₁ -V ₂ ) with a negative peak value of (-V ₁ + V 2 The AC pulse of ₂ ) is applied alternately for each period of t ₁₄ . The pulses applied during the selection period are both equal to or higher than the saturation value, but ON or OFF is selected according to the polarity of the pulse applied last. The AC pulse applied during the selection period has a very high peak value, but the pulse width is so small as 50 μsec that the liquid crystal element does not respond, conversely the memory is improved and the contrast is improved. The ratio is improved. In this example, a very excellent contrast ratio of 40: 1 was obtained.

Further, the average value of the voltage pulse applied to the liquid crystal element was zero, and the liquid crystal element was not deteriorated.

FIG. 40 is a block diagram showing an example of a concrete circuit for realizing the drive waveform shown in FIG. , Signal
The transmission gate 111 is selected, and the scan electrode waveform of 0 V and the non-selected scan electrode waveform of 0 V are selected by the scan electrode data of to generate the scan electrode waveform. On the other hand, the signal electrode waveform depends on the signal of the transmission gate 111.
Is selected to select the ON waveform and the OFF waveform of the signal electrode data to create a signal electrode waveform, which is applied to the liquid crystal element 113. ± V ₁ , ± V ₂ , 0V are power supply voltages of the scan electrodes and the signal electrodes. FIG. 41 shows signals at various points in the circuit shown in FIG.

Example 14 FIG. 42 shows driving waveforms applied to the scan electrode X ₁ and the signal electrode Y ₁ for turning on and off as shown in FIG. 2 (b) and the pixel (X ₁ Y ₁ ). 2 shows the light transmission characteristics thereof. In order to facilitate understanding of the change in light transmission characteristics, in the next frame period t ₂₃ on, by inverting the OFF state.

In FIG. 42, t ₁₃ shows the first frame period, t ₂₃ shows the next frame period, t ₁₁ and t ₂₁ show the selection period, and t ₁₂ and t ₂₂ show the non-selection period. Further, t ₁₄ indicates a pulse width of 200 μsec.

Differs from the embodiment 13, a positive is applied during the selection period t ₁₁ (t _21), the difference between the peak value of the negative pulse, the non-selection period t ₁₂ (t
₂₂ ) is corrected by the high-frequency AC pulse applied to ( ₂₂ ), so the peak values V ₁ and V ₄ of this AC pulse are
| V ₃ · t ₁₄ | − | V ₂ · t ₁₄ | = 1/2 (| V ₁ · t ₁₂ | + | V ₄ · t ₁₂ |)
Is set to satisfy. In the case of this embodiment, t ₁₂ = 1
Since it is 0t ₁₄ , the peak values V ₁ , V ₂ , V ₃ and V ₄ are 30V and 10V, respectively.
It was V, 20V, 28V. V ₅ is 5V.

On the scan electrode X ₁ , −V ₃ and V ₂ are negative and positive in the selection period t ₁₁ (t ₂₁ ), and a positive peak value is in the non-selection period t ₁₂ (t ₂₂ ).
V _1, the negative peak value by applying an AC pulse frequency 10KHz in V _4, the signal electrode Y _1, and ± V _5, if if you want to turn on the pixels to be turned off positive, negative order is negative , Apply in positive order. At this time, when the pixel (X ₁ Y ₁ ) is on, (−V ₃ −V ₅ ) and (+ V ₂ + V ₅ ) above the saturation value are applied, and when it is off, a negative value above the saturation value is applied. pulse (-. ₃ + V ₅₎ and less than the threshold (+ V ₂ -V ₅₎ is applied. In the non-selection period, an AC pulse with a positive peak value of (+ V ₁ + V ₅ ) and a negative peak value of (−V ₄ + V ₅ ) and a positive peak value of (+ V ₁ −V −
V ₅₎ negative peak value at the (-V ₄ -V ₅₎ AC pulse and the t ₁₄ of
Are alternately applied for each period. The difference between the peak values of the positive and negative pulses applied during the selection period is (V ₃ −V ₂ ) regardless of whether it is on or off, and the difference is corrected by the AC pulse applied during the non-selection period. Then, the average value of the voltage pulse applied to the liquid crystal element becomes zero. Also in this example, the memory property of the liquid crystal element was improved, and the same excellent contrast ratio as in Example 13 was obtained.

FIG. 43 is a circuit block diagram of an example of a specific circuit for realizing the drive waveform shown in FIG. , Signal
The transmission gate 111 is selected, and the scan electrode waveform at the time of selection and the scan electrode waveform at the time of non-selection are selected by the scan electrode data of to generate the scan electrode waveform. On the other hand, the signal electrode waveform depends on the signal of the transmission gate 11
The ON waveform and the OFF waveform in the signal electrode data of 1 are selected to form a signal electrode waveform, which is applied to the liquid crystal element 113. _{V 1, V 2, -V 3} , -V 4, ± V 5 is the supply voltage of the scanning electrodes and signal electrodes. FIG. 44 shows signals at various points in the circuit shown in FIG.

Example 15 FIG. 45 is a block diagram showing a concrete circuit for realizing the drive waveform in this example, and FIG. 81 is a drive circuit for applying the drive waveform made by this circuit to a liquid crystal element. It is a figure which shows an example of a circuit. 451 frame signal, 452 is a polarity switching signal, these signals, V ₁ and switching-trans honey Chillon gate _{111, V 2, -V 3,} -V 4
The voltage is switched to generate the selection waveform 453 of the scan electrode. Also, by switching the voltage of V ₅ and -V ₆ , the signal electrode is turned on.
And make off waveform 455. FIG. 46 shows the timing chart of these signal waveforms.

These signal waveforms are applied to the drive circuit shown in FIG. 81 to create drive waveforms applied to the scan electrodes and the signal electrodes. In other words, select waveform 453 to 8101 and 8102, 0V to 8103 as non-select waveform, ON waveform 454 to 8105, OFF waveform 455.
Apply to 8104 respectively.

In FIG. 81, reference numeral 121 denotes scan electrode data, which is transferred to the scan electrode side shift register 115 by the scan electrode shift clock 120 and sequentially outputs a selection signal for each scan electrode to switch the transmission gate 111. ,
The scan electrode drive waveform is applied to 8107. Further, 117 is signal electrode data, which is transferred to the signal electrode side shift register 114 by the signal electrode shift clock 118, and when the data for one scanning electrode is transferred, it is latched to the latch circuit 116 by the latch signal 119. The output of the latch circuit 116 switches the transmission gate 111 to switch the ON waveform 454 and the OFF waveform 455 and apply the signal electrode drive waveform to 8106.

FIG. 46 shows the scan electrode 8109 and the signal electrode 81 shown in FIG.
10 shows a drive waveform applied to 10, a composite waveform applied to the pixel 8111, and light transmission characteristics.

t ₁₃ , t ₂₃ , t _33, and t ₄₃ are one frame period, t
₁₁ , t ₂₁ ,, t ₃₁ and t ₄₁ are the selection period, t ₁₂ , t ₂₂ , t, respectively.
₃₂ and t ₄₂ each represent a non-selection period. Also t ₁₄ ,
t ₁₅ , t ₂₄ , t ₂₅ , t ₃₄ , t ₃₅ , t ₄₄ and t ₄₅ indicate pulse widths, and in the case of the present embodiment, all are 200 μsec.

The peak values V ₁ and V ₄ are 10V, V ₂ and V ₃ are 8V, and V ₅ and V ₆ are 2V.

For the scan electrode X ₁ , as shown in FIG. 461, the selection period t ₁₁
(T ₂₁ , t ₃₁ , t ₄₁ ) are alternated for each frame alternately in the order + V ₂ and −V ₄ are negative and positive as the first selection waveform, and + V ₁ and −V as the second selection waveform. ₃ is applied in the order of positive and negative, and 0 V is applied during the non-selection period t ₁₂ (t ₂₂ , t ₃₂ , t ₄₂ ). Further, as shown in FIG. 46, 462, the signal electrode Y ₁ is
If you want to turn on the pixel + V ₅ and -V ₆ positive, negative sequence, if it is desired to turn off + V ₅ and -V ₆ is negative, it is applied to the positive order.

The composite waveform applied to the pixel (X ₁ Y ₁ ) at this time is shown in FIG.
As shown in FIG. 3, in the frame in which the first selection waveform is applied to the scan electrode X ₁ , (−V ₄ −V ₅ ) and (V ₂ + V ₆ ) are turned off in the order of negative and positive when on. In case of (-V ₄ + V ₆ )
In the frame where (V ₂ −V ₅ ) and (V ₂ −V ₅ ) are applied in the order of negative and positive, and the second selection waveform is applied, (V ₁ −
V ₅ ) and (-V ₃ + V ₆ ) are applied in the order of positive and negative, and when off (V ₁ + V ₆ ) and (-V ₃ -V ₅ ) are applied in the order of positive and negative. Moreover, −V ₅ and + V ₆ are applied during the non-selection period.

In the driving method of this embodiment, a positive or negative saturation value or more pulse is applied at the beginning of the selection period to turn it on or off, and a pulse to be applied next is turned on or off as a reverse polarity saturation value or more pulse. ON or OFF is selected depending on whether the state is reversed or the pulse is held as it is as a pulse having a polarity of the opposite polarity. In the frame to which the first selection waveform is applied, the difference in peak value between the positive pulse and the negative pulse is (V ₄ −V ₂ ), that is, −2V.
In the frame to which the selection waveform of ( ₁ ) is applied, (V ₁ −V ₃ ), that is, + 2V, is canceled out. That is,
In this embodiment, the average value of the voltage pulse applied to the pixel every two frames is set to zero to prevent the deterioration of the liquid crystal element. The light transmission characteristics of the pixel 8111 are shown in FIG.
Shown in.

Sixteenth Embodiment FIG. 47 is a block diagram showing a concrete circuit for realizing the drive waveforms in this embodiment, and FIG. 81 is a drive circuit for applying the drive waveform made by this circuit to a liquid crystal element. It is a figure which shows an example of a circuit. 471 frame signal, 472 is a polarity switching signal, these signals, V ₁ and switching-trans honey Chillon gate _{111, -V 2, -V 7,} -
Switch the voltage of V ₈ and create the scanning electrode selection waveform 473,
Non-selection waveform 474 of scan electrode by switching the voltage of −V ₃ and −V _6.
make. _{Further, -V 2, -V 4, -V} 5, making on waveforms 475 and off waveform 476 of the signal electrodes by switching the voltage of -V _7. First
Figure 48 shows the timing chart of these signal waveforms.

These signal waveforms are applied to the drive circuit shown in FIG. 81 to create drive waveforms applied to the scan electrodes and the signal electrodes. That is, the selected waveform 473 is set to 8101 and 8102 and the non-selected waveform 474 is set.
Is applied to 8103, the on waveform 475 is applied to 8105, and the off waveform 476 is applied to 8104.

In FIG. 81, reference numeral 121 denotes scan electrode data, which is transferred to the scan electrode side shift register 115 by the scan electrode shift clock 120 and sequentially outputs a selection signal for each scan electrode to switch the transmission gate 111. The scan electrode drive waveform is applied to 8107. Further, 117 is signal electrode data, which is transferred to the signal electrode side shift register 114 by the signal electrode shift clock 118, and when the data for one scanning electrode is transferred, the latch circuit 1 is sent by the latch signal 119.
Latch to 16. The output of the latch circuit 116 switches the transmission gate 111 to turn on the waveform 4.
75 and OFF waveform 476 are switched to set the signal electrode drive waveform to 8
Apply to 106.

FIG. 49 shows the scan electrode 8109 and the signal electrode 81 shown in FIG.
10 shows the drive waveform applied to 10, the composite waveform applied to the pixel 8111, and the light transmission characteristics.

t ₁₃ , t ₂₃ , t _33, and t ₄₃ are one frame period, t
₁₁ , t ₂₁ ,, t ₃₁ and t ₄₁ are the selection period, t ₁₂ , t ₂₂ , t, respectively.
₃₂ and t ₄₂ each represent a non-selection period. Also t ₁₄ ,
t ₁₅ , t ₂₄ , t ₂₅ , t ₃₄ , t ₃₅ , t ₄₄ and t ₄₅ indicate pulse widths, and in the case of the present embodiment, all are 200 μsec.

Crest value V ₁ is 0V, V ₂ is 2V, V ₃ is 4V, V ₄ is 6V, V ₅ is 8V, V ₆ is 10V, V
₇ 12V, V ₈ is 14V. In addition, −Vm represents the intermediate potential of the voltage pulse applied to the signal electrode, and in this case is −7V.

The difference from Example 15 is that the voltage levels applied to the scan electrodes and the signal electrodes are made common in order to lower the voltage applied to the scan electrodes, and the selection waveform for applying the ON and OFF waveforms of the signal electrodes to the scan electrodes. This is the point that was changed.

That is, as shown in FIG.
Selection period _{t 11 (t 21, t 31} , t 41) is 1 alternately for each frame, -V ₈ and -V ₂ is -V ₈ as the first selected waveform, -V ₂
, And -V ₁ and -V ₇ as the second selection waveform
V ₁ and −V ₇ are applied in this order, and the non-selection period t ₁₂ (t ₂₂ , t ₃₂ ,
t ₄₂ ) is −V in the frame where the first selection waveform is applied.
₃ and -V ₆ is -V _3, in the order of -V _6, also -V ₆ in the frame in which the second signal is applied, it is sequentially applied to the -V _3.

As shown in FIG. 491, the signal electrode 8110 has an ON waveform of −V ₂ in the frame to which the first selection waveform is applied.
And -V ₇ are -V _2, are sequentially applied to the -V _7, the -V ₄ and -V ₅ as an off waveform -V _4, are sequentially applied to the -V _5. In the frame in which the second signal is applied, -V ₄ and -V ₅ is -V ₅ as an on waveform, is applied in order of -V _4, -V ₂ and -V ₇ as an off waveform -V ₇ , −V ₂ are applied in this order.

As shown in FIG. 493, the combined waveform applied to the pixel 8111 at this time is (−V ₈ + V ₂ ) and (−) in the frame in which the first selection waveform is applied to the scan electrodes. V ₂ +
V ₇ ) is applied in the order of negative and positive, and when turned off, (−V ₈ + V ₄ ) and (−V ₂ + V ₅ ) are applied in the order of negative and positive, and in the frame where the second selection waveform is applied, If on (V ₁ + V ₅₎ and (-V ₇ + V ₄₎ is positive, a negative order, in the case of off (V ₁ +
V ₇₎ and (-V ₈ + V ₂₎ positive, it is applied to the negative order. The non-selection _{period, (- V 6 + V 7} ) and (-V ₃ + V ₂₎ or (-V ₃ + V ₄₎ and (-V ₆ + V ₅₎ is applied.

Also in the driving method of this embodiment, a pulse having a positive or negative saturation value or more is applied at the beginning of the selection period to turn it on or off, and a pulse to be applied next is turned on or off as a pulse having a saturation value of the opposite polarity or more. ON or OFF is selected depending on whether the state is reversed or the pulse is held as it is as a pulse having a polarity of the opposite polarity. Further, in the frame to which the first selection waveform is applied, the difference in peak value between the positive pulse and the negative pulse is (V ₇ −V ₈ ) or (V ₄ + V ₅ −V ₂ −V ₈ ) or − Although it is 2V, in the frame to which the second selection waveform is applied, it is V ₂ or (V ₄ + V ₅ −V ₇ ), that is, + 2V, and they cancel each other. That is, also in this embodiment, the average value of the voltage pulse applied to the pixel every two frames is set to zero to prevent the deterioration of the liquid crystal element. The light transmission characteristics of the pixel 8111 are shown in FIG.

Example 17 FIG. 50 is a block diagram showing a concrete circuit for realizing the drive waveforms in this example, and FIG. 81 is a drive circuit for applying the drive waveforms produced by this circuit to the liquid crystal element. It is a figure which shows an example of a circuit. 501 is a frame signal, 502 is a polarity switching signal, and these signals are used to switch the transmission gate 111 to V ₁ , V ₂ , -V ₃ , -V ₄
, And the selection waveform 503 of the scan electrode is created. Also, V _5, -V _6, 0V ON waveform of the signal electrodes by switching the voltage
Make 504 and off waveform 505. FIG. 51 shows the timing chart of these signal waveforms.

These signal waveforms are applied to the drive circuit shown in FIG. 81 to create drive waveforms applied to the scan electrodes and the signal electrodes. That is, the selected waveform 503 is set to 8101 and 8102, the non-selected waveform is set to 0V to 8103, the on waveform 504 to 8105, and the off waveform 505.
Apply to 8104 respectively.

In FIG. 81, reference numeral 121 denotes scan electrode data, which is transferred to the scan electrode side shift register 115 by the scan electrode shift clock 120 and sequentially outputs a selection signal for each scan electrode to switch the transmission gate 111. ,
The scan electrode drive waveform is applied to 8107. Further, 117 is signal electrode data, which is transferred to the signal electrode side shift register 114 by the signal electrode shift clock 118, and when the data for one scanning electrode is transferred, it is latched to the latch circuit 116 by the latch signal 119. The output of the latch circuit 116 switches the transmission gate 111 to switch the ON waveform 504 and the OFF waveform 505 and apply the signal electrode drive waveform to 8106.

FIG. 51 shows the scan electrode 8109 and the signal electrode 81 shown in FIG.
10 shows the drive waveform applied to 10, the composite waveform applied to the pixel 8111, and the light transmission characteristics.

t ₁₃ , t ₂₃ , t _33, and t ₄₃ are one frame period, t
₁₁ , t ₂₁ ,, t ₃₁ and t ₄₁ are the selection period, t ₁₂ , t ₂₂ , t, respectively.
₃₂ and t ₄₂ each represent a non-selection period. Also t ₁₄ ,
t ₁₅ , t ₂₄ , t ₂₅ , t ₃₄ , t ₃₅ , t ₄₄ and t ₄₅ indicate pulse widths, and in the case of the present embodiment, all are 200 μsec.

Crest values V ₁ and V ₄ are 8V, V ₂ and V ₃ are 6V, V ₅ and V ₆ are 2V
Is.

As shown in FIG. 51 1 in FIG. 51, the scanning electrode 8109 has a selection period t ₁₁ (t ₂₁ , t ₃₁ , t ₄₁ ) alternately for each frame.
As the first selection waveform, V ₂ and −V ₄ are applied in the order of negative and positive, and as the second selection waveform, V ₁ and −V ₃ are applied in the order of positive and negative, and the non-selection period t ₁₂ (t ₂₂ , 0 V is applied to t ₃₂ and t ₄₂ ).

As shown in FIG. 51, 512, to the signal electrode 8110, in the frame to which the first selection waveform is applied, V ₅ and −V ₆ are applied in the order of positive and negative as the ON waveform and 0 V as the OFF waveform.
Is applied. Also, in the frame to which the second selection waveform is applied, 0V is applied as the ON waveform and the OFF waveform is applied.
V ₅ and −V ₆ are applied in the order of negative and positive.

At this time, the composite waveform applied to the pixel 8111 is (-V ₄ -V ₅ ) and (-V ₄ -V ₅ ) when on in the frame in which the first selection waveform is applied to the scan electrodes, as shown in FIG. V ₂ +
V ₆ ) in the order of negative and positive, and when off, −V ₄ and V ₂ are negative,
In the frame applied in the positive order and the second selection waveform is applied, V ₁ and −V _{3 are} positive and negative in the order of ON, and (V ₁ + V ₆ ) and (−V ₃ ) in the case of OFF. −V ₅ ) is applied in the order of positive and negative.

Further, 0 V or V ₅ and −V ₆ are applied during the non-selection period.

Also in the driving method of this embodiment, a pulse having a positive or negative saturation value or more is applied at the beginning of the selection period to turn it on or off, and a pulse to be applied next is turned on or off as a pulse having a saturation value of the opposite polarity or more. Although the state is reversed, ON or OFF is selected depending on whether the pulse is kept as it is as a pulse having a smaller polarity threshold value. Further, in the frame to which the first selection waveform is applied, the difference in peak value between the positive pulse and the negative pulse is (V ₂ −V ₄ ), that is, −2V, but
In the frame to which the selection waveform of ( ₁ ) is applied, (V ₁ −V ₃ ), that is, + 2V, is canceled out. That is,
Also in this embodiment, the average value of the voltage pulse applied to the pixel every two frames is set to zero to prevent the deterioration of the liquid crystal element. The light transmission characteristics of the pixel 8111 are shown in FIG.
Shown in.

Example 18 FIG. 52 is a block diagram showing a concrete circuit for realizing the drive waveforms in the present example, and FIG. 81 is a drive circuit for applying the drive waveforms produced by this circuit to the liquid crystal element. It is a figure which shows an example of a circuit. 521 frame signal, 522 is a polarity switching signal, these signals, V ₁ and switching-trans honey Chillon gate _{111, -V 2, -V 7,} -V 8
The voltage of the scanning electrode to create the selection waveform 523 of the scanning electrode,
Non-selection waveform of scan electrode 524 by switching the voltage of ₃ , -V ₆ , 0V
make. _{Further, -V 2, -V 3, -V} 6, making on waveforms 525 and off waveform 526 of the signal electrodes by switching the voltage of -V _7. First
Figure 53 shows the timing chart of these signal waveforms.

These signal waveforms are applied to the drive circuit shown in FIG. 81 to create drive waveforms applied to the scan electrodes and the signal electrodes. That is, the selection waveform 523 is set to 8101 and 8102, and the non-selection waveform 524
Is applied to 8103, the ON waveform 525 is applied to 8105, and the OFF waveform 526 is applied to 8104.

In FIG. 81, reference numeral 121 denotes scan electrode data, which is transferred to the scan electrode side shift register 115 by the scan electrode shift clock 120 and sequentially outputs a selection signal for each scan electrode to switch the transmission gate 111. The scan electrode drive waveform is applied to 8107. Further, 117 is signal electrode data, which is transferred to the signal electrode side shift register 114 by the signal electrode shift clock 118, and when the data for one scanning electrode is transferred, the latch circuit 1 is sent by the latch signal 119.
Latch to 16. The output of the latch circuit 116 switches the transmission gate 111 to turn on the waveform 5.
25 and OFF waveform 526 are switched to set the signal electrode drive waveform to 8
Apply to 106.

FIG. 54 shows the scan electrode 8109 and the signal electrode 81 shown in FIG.
10 shows the drive waveform applied to 10, the combined waveform applied to the pixel 8111, and the light transmission characteristics.

t ₁₃ , t ₂₃ , t _33, and t ₄₃ are one frame period, t
₁₁ , t ₂₁ ,, t ₃₁ and t ₄₁ are the selection period, t ₁₂ , t ₂₂ , t, respectively.
₃₃ and t ₄₂ each represent a non-selection period. Also t ₁₄ ,
t ₁₅ , t ₂₄ , t ₂₅ , t ₃₄ , t ₃₅ , t ₄₄ and t ₄₅ indicate pulse widths, and in the case of the present embodiment, all are 200 μsec.

Crest value V ₁ is 0V, V ₂ is 2V, V ₃ is 4V, V ₆ is 8V, V ₇ is 10V, V ₈ is 12V
Is. Vm represents the intermediate potential of the voltage pulse applied to the signal electrode, which is 6V in this case.

The difference from Example 17 is that the voltage levels of the scan electrodes and the signal electrodes are made common in order to lower the voltage applied to the scan electrodes.

As shown in FIG. 54, the scanning electrode 8109 has a selection period t
₁₁ (t ₂₁ , t ₃₁ , t ₄₁ ) alternates for each frame,
As the selection waveform of, -V ₈ and -V ₂ are in the order of -V ₈ and -V ₂ ,
The V ₁ and -V ₇ are V ₁ as the second selecting waveform is sequentially applied to the -V _7, the non-selection period _{t 12 (t 22, t 32} , t 42) , the first selecting waveform is applied -V ₃ and -V ₆ are
V _3, are sequentially applied to the -V _6, also in the frame in which the second signal is applied sequentially applied to the -V _6, -V _3.

As shown in FIG. 54, 542, the signal electrode 8110 has -V ₂ as an ON waveform in the frame to which the first selection waveform is applied.
And -V ₇ are -V _2, in the order of -V _7, -V ₃ and -V ₆ is -V ₃ as an off waveform is sequentially applied to the -V _6, also in the frame in which the second signal is applied -V ₃ and -V ₆ is -V ₆ as an on waveform, in order of -V _3, as an off waveform -V ₂ and -V ₇ is -V _7, are sequentially applied to the -V _2.

At this time, the combined waveform applied to the pixel 8111 is (−V ₈ + V ₂ ) and (−) when turned on in the frame in which the first selection waveform is applied to the scan electrodes, as shown in FIG. V ₂ +
V ₇ ) is applied in the order of negative and positive, and when turned off, (−V ₈ + V ₃ ) and (−V ₂ + V ₆ ) are applied in the order of negative and positive, and in the frame where the second selection waveform is applied, When on (-V ₂ + V ₇ )
And (-V ₇ + V ₃ ) are in the order of positive and negative, and (V ₁
+ V ₇ ) and (-V ₇ + V ₂ ) are applied in the order of positive and negative.

The non-selection period, 0V or (-V ₆ + V ₇₎ and (-
V ₃ + V ₂ ) is applied.

Also in the driving method of this embodiment, a pulse having a positive or negative saturation value or more is applied at the beginning of the selection period to turn it on or off, and a pulse to be applied next is turned on or off as a pulse having a saturation value of the opposite polarity or more. ON or OFF is selected depending on whether the state is reversed or the pulse is held as it is as a pulse having a polarity of the opposite polarity. Further, in the frame in which the first signal is applied, the difference between the peak value of the positive and negative pulses have summer and (V ₇ -V ₈₎ or (V ₆ -V ₇₎ That -2V However, in the frame to which the second selection waveform is applied, it becomes (V ₃ −V ₂ ) or V ₂ or + 2V,
Offset each other. That is, also in this embodiment, the average value of the voltage pulse applied to the pixel every two frames is set to zero to prevent the deterioration of the liquid crystal element. Note that the pixel
The light transmission characteristics of 8111 are shown in FIG.

Example 19 FIG. 55 is a block diagram showing a concrete circuit for realizing the driving waveform in this example, and FIG. 81 is a driving circuit for applying the driving waveform made by this circuit to a liquid crystal element. It is a figure which shows an example of a circuit. 551 is a frame signal, 552 is a polarity switching signal, and 553 is a write pulse switching signal. With these signals, the transmission gate 11
V ₁ and switching-a _{1, V 2, V 3,} -V 4, -V 5, the switching voltage of -V _6, making selecting waveform 554 of the scan electrodes. Also, V ₇ ,-
By switching the voltage of V ₈ and 0 V, the ON waveform 555 and the OFF waveform 556 of the signal electrode are created. FIG. 56 shows the timing chart of these signal waveforms.

These signal waveforms are applied to the drive circuit shown in FIG. 81 to create drive waveforms applied to the scan electrodes and the signal electrodes. That is, select waveform 554 to 8101 and 8102, 0V to 8103 as non-select waveform, ON waveform 555 to 8105, OFF waveform 556.
Apply to 8104 respectively.

In FIG. 81, reference numeral 121 denotes scan electrode data, which is transferred to the scan electrode side shift register 115 by the scan electrode shift clock 120 and sequentially outputs a selection signal for each scan electrode to switch the transmission gate 111. ,
The scan electrode drive waveform is applied to 8107. Further, 117 is signal electrode data, which is transferred to the signal electrode side shift register 114 by the signal electrode shift clock 118, and when the data for one scanning electrode is transferred, it is latched to the latch circuit 116 by the latch signal 119. The output of the latch circuit 116 switches the transmission gate 111 to switch between the ON waveform 555 and the OFF waveform 556 and apply the signal electrode drive waveform to 8106.

FIG. 56 shows the scan electrode 8109 and the signal electrode 81 shown in FIG.
10 shows the drive waveform applied to 10, the combined waveform applied to the pixel 8111, and the light transmission characteristics.

t ₁₃ , t ₂₃ , t _33, and t ₄₃ are one frame period, t
₁₁ , t ₂₁ ,, t ₃₁ and t ₄₁ are the selection period, t ₁₂ , t ₂₂ , t, respectively.
₃₂ and t ₄₂ each represent a non-selection period. Also t ₁₄ ,
t ₁₅ , t ₂₄ , t ₂₅ , t ₃₄ , t ₃₅ , t ₄₄ and t ₄₅ indicate pulse widths, and in the case of the present embodiment, all are 200 μsec. Also, the pulse width of the write pulse switching signal (hereinafter t / 4
Is 1/4 of the pulse width, that is, 50 μsec.

Crest values V ₁ and V ₄ are 9V, V ₂ and V ₅ are 6V, V ₃ and V ₆ are 11
V, V ₇ and V ₈ are 3V.

In the present embodiment, the write pulse switching signal is superimposed on the drive waveform to reduce the pulse width of the pulse applied to the pixel during the non-selection period and further reduce the influence on the light transmission characteristics.

As shown in FIG. 561, the scan electrode 8109 has a selection period t.
₁₁ (t ₂₁ , t ₃₁ , t ₄₁ ) alternates for each frame,
As the second selection waveform, the pulses in which the write pulse switching signal is superimposed on −V ₆ and V ₂ are negative and positive, and the pulses in which the write pulse switching signal is superimposed on V ₁ and −V ₅ are the selection waveforms. The voltages are applied in the order of positive and negative, and 0 V is applied during the non-selection period t ₁₂ (t ₂₂ , t ₃₂ , t ₄₂ ).

As shown in FIG. 561, the signal electrode 8110 is first applied with two on-waveforms by alternately applying 0V and V ₇ with a pulse width of t / 4, and then applying −V ₈ and with the same pulse width. Two 0V are alternately applied. A pulse having an opposite phase to the on waveform is applied as the off waveform.

At this time, the composite waveform applied to the pixel 8111 is -V ₆ with a part of -V ₇ in the frame in which the first selection waveform is applied to the scan electrodes, as shown in FIG. Superposed pulse and (V ₂ + V ₈ ) = V ₁ is applied, and when it is off, partial pulse of V ₈ is superposed on −V ₆ and (V ₁ −V ₇ ) = V ₂
Is applied. In the frame to which the second selection waveform is applied, a pulse in which part of -V ₇ is superimposed on V ₃ and (-V ₄ + V ₈ ) =-V ₅ are applied when it is on, and V when it is off. A pulse in which V ₆ is partially superimposed on ₃ and (−V ₅ −V ₇ ) = − V ₄ are applied.

During the non-selection period, 0V, V ₇ and −V ₈ are applied with a pulse width of t / 4.

In this embodiment, the pulse applied at the beginning of the selection period and having V ₃ or ± V ₇ or ± V ₈ superposed on a part thereof is equal to or higher than the saturation value, so that the pixel is turned on or off immediately. State, and if the pulse of the opposite polarity to the first pulse applied next is greater than or equal to the saturation value or less than the threshold value, ON,
ON or OFF is selected depending on whether the OFF state is inverted or kept as it is. Further, in the frame in which the first signal is applied, the difference between the peak value of the positive pulse and negative pulse _{(-V 6 + V 7/2} -V 1) = (V 6 -V 8 / 2- V ₂₎ i.e. although summer and -3.5 V, in the frame in which the second signal is _{applied, (V 3 -V 7/2} -V 5) = (V 3 + V 8/2-V 4) in other words It becomes + 3.5, V and they cancel each other out. That is, also in this embodiment, the average value of the voltage pulse applied to the pixel every two frames is set to zero to prevent the deterioration of the liquid crystal element. The light transmission characteristics of the pixel 8111 are shown in FIG.
Shown in.

Further, in the present embodiment, the pulse width of the pulse superimposed on the drive waveform is set to t / 4, but the present invention is not limited to this, and the pulse width may be made smaller to increase the number of superimposed pulses. .

Embodiment 20 FIG. 57 is a block diagram showing a specific circuit for realizing the drive waveforms in this embodiment, and FIG. 81 is a drive circuit for applying the drive waveforms produced by this circuit to the liquid crystal element. It is a figure which shows an example of a circuit. 571 is a frame signal, 572 is a polarity switching signal, and 573 is a write pulse switching signal. With these signals, the transmission gate 111
V ₁ and _{switching-a, -V 2, -V 3, -V} 6, -V 7, switching a voltage of -V _8, make a selection waveform 574 of scan electrodes ,, V _3, -
The voltage of V ₆ is switched to create the non-selected waveform 575 of the scan electrodes. _{Further, -V 2, -V 3, -V} 5, -V 6, making on waveforms 576 and off waveform 577 of the signal electrodes by switching the voltage of -V _7. First
Figure 58 shows the timing chart of these signal waveforms.

These signal waveforms are applied to the drive circuit shown in FIG. 81 to create drive waveforms applied to the scan electrodes and the signal electrodes. That is, the selected waveform 574 is changed to 8101 and 8102, and the non-selected waveform 575 is
Is applied to 8103, the ON waveform 576 is applied to 8105, and the OFF waveform 577 is applied to 8104.

In FIG. 81, reference numeral 121 denotes scan electrode data, which is transferred to the scan electrode side shift register 115 by the scan electrode shift clock 120 and sequentially outputs a selection signal for each scan electrode to switch the transmission gate 111. ,
The scan electrode drive waveform is applied to 8107. Further, 117 is signal electrode data, which is transferred to the signal electrode side shift register 114 by the signal electrode shift clock 118, and when the data for one scanning electrode is transferred, it is latched to the latch circuit 116 by the latch signal 119. The output of the latch circuit 116 switches the transmission gate 111 to switch between the ON waveform 576 and the OFF waveform 577 and apply the signal electrode drive waveform to 8106.

FIG. 59 shows the scan electrode 8109 and the signal electrode 81 shown in FIG.
10 shows the drive waveform applied to 10, the composite waveform applied to the pixel 8111, and the light transmission characteristics.

t ₁₃ , t ₂₃ , t _33, and t ₄₃ are one frame period, t
₁₁ , t ₂₁ ,, t ₃₁ and t ₄₁ are the selection period, t ₁₂ , t ₂₂ , t, respectively.
₃₂ and t ₄₂ each represent a non-selection period. Also t ₁₄ , t
₁₅ , t ₂₄ , t ₂₅ , t ₃₄ , t _44, and t ₄₅ represent pulse widths, and in the case of the present embodiment, all are 200 μsec. Also, the pulse width of the write pulse switching signal (hereinafter referred to as t / 4)
Is 1/4 of the pulse width, that is, 50 μsec.

Crest value V ₁ is 0V, V ₂ is 2V, V ₃ is 4V, V ₄ is 6V, V ₅ is 8V, V ₆ is 10V, V
₇ is 12 V, V ₈ is 14 V, and Vm is the intermediate potential of the pulse applied to the signal electrode, which is 7 V in this case.

The difference from Example 19 was that the voltage levels applied to the scan electrodes and the signal electrodes were made common in order to lower the voltage applied to the scan electrodes, and the on / off waveforms were changed according to the selection waveform. is there.

As shown in FIG. 591, the scanning electrode 8109 has a selection period t
₁₁ (t ₂₁ , t ₃₁ , t ₄₁ ) alternates for each frame,
As the second selection waveform, the pulse in which the write pulse switching signal is superimposed on -V ₈ and -V ₃ as the selection waveform of
V ₁ and pulse write pulse change-signal is superimposed on a -V ₇ is applied, the non-selection period _{t 12 (t 22, t 32} , t 42) is -V ₃ and -V ₆ is, -V _3, forward or -V ₆ of -V _6, are sequentially applied to the -V _3.

As shown in FIG. 59, the signal electrode 8110 has -V ₂ as an ON waveform in the frame to which the first selection waveform is applied.
And −V ₃ are applied to each other with a pulse width of t / 4, and then −V ₇ and −V ₆ are applied with 2 pulses alternately with the same pulse width. After -V ₃ and -V ₄ are applied alternately at 2 times each, -V ₆ and -V ₅
2 are alternately applied with the same pulse width. The second
In the frame to which the selected waveform is applied, a pulse having an opposite phase to the off waveform is applied as an on waveform, and a pulse having an opposite phase to the on waveform is applied as an off waveform.

As shown in FIG. 593, the composite waveform applied to the pixel 8111 at this time is partially (−V ₈ + V ₃ ) when ON in the frame in which the first selection waveform is applied to the scan electrodes. (V ₂ −
V ₃₎ pulses and are superimposed _{(-V 3 + V 7) =} (- V 2 +
V ₆ ) is applied, and when it is off (-V ₈ + V ₄ ), a part (V ₃ −
V ₄₎ pulses and are superimposed _{(-V 3 + V 6) =} (- V 2 +
V ₅ ) is applied. Further, in the frame to which the second selection waveform is applied, a pulse in which a part (V ₅ −V ₆ ) is superimposed on (V ₁ + V ₆ ) and (−V ₆ + V ₃ ) = (− V ₇ + V ₄ ) is applied, and when off (V ₁ + V ₇ ) a partial pulse (V ₆ −V ₇ ) is superimposed and (−V ₆ + V ₂ ) = (− V ₇ + V ₃ ) is applied. It

Non-selection period _{is, 0V, (- V 6 +} V 7) and (-V ₃ + V ₂₎ is t
It is applied with a pulse width of / 4.

The composite waveform applied to the pixel by the driving method of the present embodiment is basically the same as that of the nineteenth embodiment, and the difference between the positive pulse and the negative pulse in the frame to which the first selection waveform is applied. There _{(V 8 -V 2/2-} V 3/2-V 6 + V 2) = (V 8 -V 3/2-V 4/2
-V ₅ + V ₂₎ That -3 V, the frame in which the second signal is _{applied, (V 6/2 + V} 7/2 + V 3 -V 7) = (V 5/2 + V 6/2
+ V ₄ −V ₇ ) or + 3V cancel each other out, and the average value becomes zero every two frames. The light transmission characteristics of the pixel 8111 are shown in FIG. 59, 594.

In the embodiments described so far, the ferroelectric liquid crystal TDOB is used.
Although each voltage level is set according to the threshold characteristic of the AMBCC, the present invention is not limited to this, of course, and each voltage level is appropriate depending on the threshold characteristic of the ferroelectric liquid crystal used. Just set the value.

Example 21 FIGS. 82 (a) and 82 (b) are diagrams showing the relationship between the waveform of the applied voltage pulse and the light transmission characteristics. As mentioned above, the threshold voltage and the saturation voltage of the ferroelectric liquid crystal change depending on the pulse width, but we have found that they also change depending on the applied pulse. That is, as shown by the solid line in FIG. 82 (a) 824, when a pulse having a waveform as shown in FIG. 82 (b) 821 is applied, the positive and negative threshold values are Vth ₁₁
And Vth ₁₂ , the saturation values are Vsat ₁₁ and Vsat ₁₂ , but
When a pulse as shown in FIG. 82 (b) 822 is applied,
As shown by the dotted line in Fig. (A) 825, the positive and negative threshold values are V
th ₂₁ and Vth ₂₂ , the saturation values are Vsat ₂₁ and Vsat ₂₂ , and 821
The absolute value is larger than when the waveform is applied, and when a pulse with a waveform as shown in 823 is applied, the positive and negative threshold values are Vth ₁ and Vth ₂ , and the saturation value is as shown by the dashed line in 826. The absolute value becomes smaller with Vsat ₁ and Vsat ₂ .

In particular, since Vth ₂₁ > Vsat ₁₁ and | Vth ₂₂ |> | Vsat ₂₁ |, the pulse of 822 waveform was applied even when the voltage level of 821 waveform was saturated value or more when the pulse was applied. Sometimes it is below the threshold and the liquid crystal element does not respond. Therefore, it becomes possible to control response and non-response at the same voltage level. The present embodiment is a driving method utilizing the threshold characteristic of such a ferroelectric liquid crystal.

FIG. 60 is a block diagram showing a concrete circuit for realizing the drive waveforms in the present embodiment, and FIG. 81 is an example of a drive circuit for applying the drive waveforms produced by this circuit to the liquid crystal element. FIG. 601 frame signal, 602 is a polarity switching signal, these signals, V ₁ and switching-trans honey Chillon gate _{111, V 2, -V 3,} -V 4
The voltage is switched to create a scan electrode selection waveform 604. Also, with the polarity switching signal 602 and the clock pulse 603,
0V, V _5, on the waveform of the signal electrodes by switching the voltage of -V ₅ 605
And make off waveform 606. FIG. 61 shows the timing chart of these signal waveforms.

These signal waveforms are applied to the drive circuit shown in FIG. 81 to create drive waveforms applied to the scan electrodes and the signal electrodes. That is, the selection waveform 604 is set to 8101 and 8102, 0V is set to 8103 as the non-selection waveform, the ON waveform 605 is set to 8105, and the OFF waveform 606 is set.
Apply to 8104 respectively.

In FIG. 81, reference numeral 121 denotes scan electrode data, which is transferred to the scan electrode side shift register 115 by the scan electrode shift clock 120 and sequentially outputs a selection signal for each scan electrode to switch the transmission gate 111. ,
The scan electrode drive waveform is applied to 8107. Further, 117 is signal electrode data, which is transferred to the signal electrode side shift register 114 by the signal electrode shift clock 118, and when the data for one scanning electrode is transferred, it is latched by the latch circuit 119 to the latch circuit 116. The output of the latch circuit 116 switches the transmission gate 111 to switch the ON waveform 605 and the OFF waveform 606 and apply the signal electrode drive waveform to 8106.

FIG. 62 shows the scan electrode 8109 and the signal electrode 81 shown in FIG.
10 shows the drive waveform applied to 10, the composite waveform applied to the pixel 8111, and the light transmission characteristics.

t ₁₃ , t ₂₃ , t _33, and t ₄₃ are one frame period, t
₁₁ , t ₂₁ ,, t ₃₁ and t ₄₁ are the selection period, t ₁₂ , t ₂₂ , t, respectively.
₃₂ and t ₄₂ each represent a non-selection period. Also t ₁₄ , t
₂₄ , t _34, and t ₄₄ are pulse widths of pulses applied in the first half of the selection period, and t ₁₅ , t ₂₅ , t _35, and t ₄₅ are pulse widths of pulses applied in the second half of the selection period, respectively. In the case of this embodiment, the pulse widths are the same. Furthermore, t ₀ represents a pulse width that is 1/2 of the above t ₁₅ (t ₂₅ , t ₃₅ , t ₄₅ ).

The peak values V _{1 to} V ₅ are set so as to satisfy the following conditions.

V ₁ = V ₄ > Vsat ₁ , | Vsat ₂ | V ₅ <Vth ₁ , | Vth ₂ | | V ₂ | = | V ₃ | Vth ₂₁ > (V ₂ + V ₅ )> Vsat ₁₁ | Vth ₂₂ |> ( V ₃ + V ₅ )> | Vsat ₁₂ | As shown in FIG. 62, the scanning electrode 8109 has the −V ₄ and V _{2 in} the order of negative and positive as the first selection waveform during the selection period.
As the second selection waveform, V ₁ and −V _{3 are} positive and negative in order of 1
It is applied alternately for each frame, and 0 V is applied during the non-selection period.

As shown in FIG. 62 622, when it is desired to turn on the signal electrode 8110, ₀ V is applied for a period of 2t ₀ and then V _{5 having a} pulse width t ₀ is applied.
And -V ₅ positive, is applied to the negative of the forward, V ₅ and -V ₅ of the pulse width t ₀ after the period also 2t ₀ if you want to off 0V is applied a negative, is applied to the positive order.

In the frame in which the first selection waveform is applied to the scan electrodes, the combined waveform applied to the pixel 8111 at this time is first applied with −V ₄ in the first half after being applied in the first half, as shown in FIG. the peak value of the t t ₀ in the second half at the peak value (V ₂ -V ₅₎ of ₀ (V ₂ +
If a pulse of V ₅ ) is applied, and if it is off, −V ₄ is also applied first, and then the peak value of t _{0 in} the first half is (V ₂ + V ₅ ) and the peak _value of t ₀ in the latter half is (V A pulse that is _2- V ₅ ) is applied. Further, in the frame to which the second selection waveform is applied, when V ₁ is _first applied in the ON state, the peak value of t _{0 in} the first half is (−V ₃ −V ₅ ) and the peak _value of t ₀ in the latter half is When a pulse of (−V ₃ + V ₅ ) is applied and V ₁ is also applied when it is off, the peak _value of t _{0 in} the first half is (−V ₃ + V ₅ ) and the peak value of t ₀ in the latter half is applied. A pulse of (−V ₃ −V ₅ ) is applied. During the non-selection period, 0 V and ± V ₅ with pulse width t ₀ are applied.

In the present embodiment, as shown in FIGS. 82 (a) and (b), the pulse applied in the latter half of the selection periods t ₁₁ and t ₂₁ is equal to or higher than the saturation value, but the pulse of t ₃₁ and t ₄₁ The pulse applied in the latter half has a value smaller than the threshold because the waveforms are different although they have the same peak value. As a result, the driving method of the present embodiment also turns on or off by a pulse having a positive or negative saturation value or more applied at the beginning of the selection period, and the state is changed by a pulse of a reverse polarity applied next. Can be turned on or off by selecting whether to invert or hold.

Further, in the frame to which the first selection waveform is applied, the difference in peak value between the positive pulse and the negative pulse is (V ₂ + V ₅ ) / 2 +
_{(V 2 -V 5) / 2} -V 4 = V 2 -V 4, the frame in which the second signal is applied _{(-V 3 -V 5) / 2} + (- V 3 + V 5) / 2 + V 1 =
Since V ₁ −V ₃ and V ₁ = V ₄ and V ₂ = V ₃ , they cancel each other out. That is, also in this embodiment, the average value of the voltage pulse applied to the pixel every two frames becomes zero, and the deterioration of the liquid crystal element can be prevented. The light transmission characteristics of the pixel 8111 are shown in FIG.

Embodiment 22 This embodiment is also a driving method utilizing the threshold characteristic of the ferroelectric liquid crystal as shown in FIGS. 82 (a) and (b).

FIG. 63 is a block diagram showing a concrete circuit for realizing the drive waveforms in the present embodiment, and FIG. 81 is an example of a drive circuit for applying the drive waveforms produced by this circuit to the liquid crystal element. FIG. Reference numeral 631 is a frame signal, and 632 is a polarity switching signal. These signals switch the transmission gate 111 to V ₁ , -V ₂ , -V ₇ , -V ₈
The voltage of the scan electrode to create the scan electrode selection waveform 634, and
The non-selected waveform 635 of the scan electrode is created by switching the voltage of ₃ , −V ₆ . In addition, the polarity switching signal 632 and clock pulse 6
By a _{33, -V 2, -V 3,} -V 4, -V 5, -V 6, making on waveforms 636 and off waveform 637 of the signal electrodes by switching the voltage of -V _7. FIG. 64 shows the timing chart of these signal waveforms.

These signal waveforms are applied to the drive circuit shown in FIG. 81 to create drive waveforms applied to the scan electrodes and the signal electrodes. That is, the selected waveform 634 is set to 8101 and 8102, and the non-selected waveform 635 is set.
Is applied to 8103, ON waveform 636 is applied to 8105, and OFF waveform 637 is applied to 8104.

In FIG. 81, reference numeral 121 denotes scan electrode data, which is transferred to the scan electrode side shift register 115 by the scan electrode shift clock 120 and sequentially outputs a selection signal for each scan electrode to switch the transmission gate 111. The scan electrode drive waveform is applied to 8107. Further, 117 is signal electrode data, which is transferred to the signal electrode side shift register 114 by the signal electrode shift clock 118, and when the data for one scanning electrode is transferred, the latch circuit 119 is used to operate the latch circuit 1.
Latch to 16. The output of the latch circuit 116 switches the transmission gate 111 to turn on the waveform 6
36 and OFF waveform 637 are switched to set the signal electrode drive waveform to 8
Apply to 106.

FIG. 65 shows the scan electrode 8109 and the signal electrode 81 shown in FIG.
10 shows the drive waveform applied to 10, the combined waveform applied to the pixel 8111, and the light transmission characteristics.

t ₁₃ , t ₂₃ , t _33, and t ₄₃ are one frame period, t
₁₁ , t ₂₁ ,, t ₃₁ and t ₄₁ are the selection period, t ₁₂ , t ₂₂ , t, respectively.
₃₂ and t ₄₂ each represent a non-selection period. Also t ₁₄ , t
₂₄ , t _34, and t ₄₄ are the pulse widths of the pulses applied in the first half of the selection period, respectively, t ₁₅ , t ₂₅ , t _35, and t ₄₅ are the pulse widths of the pulses applied in the second half of the selection period, respectively. In the case of this embodiment, the pulse widths are the same. Furthermore, t ₀ represents a pulse width that is 1/2 of the above t ₁₅ (t ₂₅ , t ₃₅ , t ₄₅ ).

The difference from Example 21 is that the voltage levels applied to the scan electrodes and the signal electrodes were made common in order to lower the voltage applied to the scan electrodes, and therefore the ON waveform and the OFF waveform were changed.
The point is that it is changed according to the selected waveform.

The peak values V _{1 to} V ₈ and Vm are set so as to satisfy the following conditions.

V ₁ = 0 (V ₁ + V ₆ )> Vsat ₁ (V ₈ −V ₃ )> | Vsat ₂ | (V ₇ −V ₆ ) = (V ₄ −V ₃ ) <Vth ₁ (V ₆ −V ₅ ) _{= (V 3 -V 2) <} | Vth 2 | Vth 21> (V 7 -V 2)> Vsat 11 | Vth 22 |> (V 7 -V 2)> | Vsat 12 | (Vm-V 2) = (V ₇ −Vm) As shown in FIG. 651, the scan electrode 8109 has −V _{8 in} the first half as the first selection waveform in the selection period, −V ₂ in the second half, and the first half as the second selection waveform in the second half. Is applied to V ₁ , and -V ₇ is applied to the latter half,
Non-selection period is -V ₆ and -V ₃ is -V _6, forward or -V ₃ of -V _3, are sequentially applied to the -V _6.

In the frame to which the first selection waveform is applied to the signal electrode 8110, as shown in FIG. 65, -V ₃ is first displayed as the ON waveform, and then −V ₅ and −V ₇ having the pulse width t ₀ are generated. −V ₅ , −V
_It is applied in the order of ₇ , and after -V ₃ as an off waveform,
Applied in order of −V ₇ and −V ₅ . Further, in the frame to which the second selection waveform is applied, -V ₆ is applied as the ON waveform first, and -V ₄ and -V ₂ having the pulse width t ₀ are applied in the order of -V ₂ -V _{4 in} the latter half, and the OFF waveform is applied. Similarly, after −V ₆ , they are applied in the order of −V ₄ and −V ₂ .

At this time, as shown in FIG. 653, the composite waveform applied to the pixel 8111 is first applied with (−V ₈ + V ₃ ) in the frame in which the first selection waveform is applied to the scan electrodes. after peak value of the first half of t ₀ is the peak value of t ₀ in the second half (-V ₂ + V ₅₎ the pulse is (-V ₂ + V ₇₎ is applied, in the case of off, again first (- V ₈ + V ₃ ) is applied, then the first half t ₀
The peak value of the peak value of the second half of t ₀ in _{(-V 2 + V 7) (} -V 2 +
A pulse that is V ₅ ) is applied. In the frame to which the second selection waveform is applied, when ON, first, (V ₁ + V ₆ ) is applied, and then the peak value of t _{0 in} the first half is (−V ₇ + V ₂ ) and t _{0 in} the latter half. A pulse with a peak value of (-V ₇ + V ₄ ) is applied,
When it is off, after (V ₁ + V ₆ ) is also applied, the first half t ₀
The peak value of the peak value of t ₀ of the second half _{(-V 7 + V 4) (} -V 7 +
A pulse that is V ₂ ) is applied. 0V during non-selected period,
(-V ₆ + V ₇₎ and (-V ₆ + V ₅₎ is applied.

The synthesized waveform according to the present embodiment is substantially the same as that of the twenty-first embodiment, and ON / OFF can be selected similarly and
The average value of the voltage pulse applied to the pixel for each frame becomes zero. The light transmission characteristics of the pixel 8111 are shown in FIG.

Example 23 This example is also a driving method utilizing the threshold characteristic of the ferroelectric liquid crystal as shown in FIGS. 82 (a) and 82 (b).

FIG. 66 is a block diagram showing a specific circuit that realizes the drive waveforms in this embodiment. 661 is a frame signal, and 6
Reference numeral 62 is a polarity switching signal. 664 is a frame signal 6
61 is a delay signal and 665 is a rotation signal of the polarity switching signal 662. These signals enable the transmission gate 11
By switching 1 to switch the voltages of V ₁ , V ₂ , -V ₃ and -V ₄ , 666 odd scan electrode selection waveform and 667 even scan electrode selection waveform are created. Also, by switching the transmission gate 111 with the clock pulse 663, V
_5, and Sakutsu an on waveform 668 and the signal electrode off waveform 669 of the signal electrodes by switching the voltage of -V _5. The timing chart of these waveforms is shown in FIG. Fig. 66 666,667,668,66
The signal of 9 is input to the drive circuit of Fig. 81, and 666 is 8101 and 66.
7 is connected to 8102, 668 is connected to 8105, 669 is connected to 8104, and 8103 is connected to 0 volt. FIG. 81 shows scan electrode data, which is transferred to the scan electrode side shift register 115 by the shift clock 120 and sequentially outputs a selection signal for each scan line. By this selection signal, the transmission gate 111 is switched to generate an odd scan electrode waveform 8107 and an even scan electrode selection waveform 8108. Fig. 81
117 is the signal electrode data, which is transferred to the signal electrode side shift register of 114 by the shift clock of 118,
When the data for one scanning line is transferred, the latch signal of 119 latches to the latch circuit of 116. The output of this latch circuit switches the transmission gate of 111 to switch the signals of 8104 and 8105 to form the signal electrode waveform of 8106. Waveform of 8107, 8108, 8106 and
This composite waveform is shown in the timing chart of 681,682,683,684 in FIG.

The drive conditions of this drive waveform are as follows.

The operation of the liquid crystal element in the pixel shown in FIG. 81 in FIG. 81 is described below. The erase pulse applied immediately before an odd frame in FIG. 68, t ₀₄ , and the voltage of | −V ₄ −V ₅ |> | Vsat ₂₂ | Apply a pulse to turn off the memory state in front of the liquid crystal element to turn it off, and during t ₁₁ is an odd frame selection period, and whether the waveform applied to the signal electrode is an on waveform or an off waveform. Therefore, the combined voltage with the scan electrode waveform is
The waveform indicated by 1 or the waveform indicated by 822 is selected. If the waveform indicated by 821, the liquid crystal element is in the on state, and if the waveform indicated by 822 is in the off state. And the non-selected period
During t ₁₂ , only the voltages V ₅ and −V ₅ whose absolute values are smaller than the threshold voltage are applied to the liquid crystal element, and therefore the written state is maintained during t ₁₁ . Further, while writing data to the liquid crystal element during the selection period t ₁₁ , at the same time, an erase panel is applied to the liquid crystal element to be selected next as indicated by 682 to erase the previous memory state. ing. Next, regarding an even frame, in the erase panel in which t ₁₄ is applied immediately before the even frame, t ₁₄ immediately before the odd frame is applied.
When the ₀₄ opposite polarity pulses, in (V ₁ + V _5)> applying a voltage pulse of Vsat ₂₁ is turned on to erase the previous memory state of the liquid crystal element, the selection period during t _21, the signal Depending on whether the waveform applied to the electrode is an on waveform or an off waveform, the combined voltage with the scanning electrode waveform is selected from the waveform shown by 821 in FIG. 82 or the waveform shown by 822, and 821 The liquid crystal element has an off state with the waveform shown by, and remains on with the waveform shown by 822. Then, during the non-selection period t ₂₂ holds the state of being written during the same at t ₂₁ and the time of the odd frame. Further, while writing data to the liquid crystal element during the selection period t ₂₁ , at the same time, an erase pulse is applied to the next selected liquid crystal element as indicated by 682 to erase the previous memory state. There is. As described above, by simultaneously writing the data to the liquid crystal element and applying the erase pulse to the liquid crystal element to be selected next, the selection period can be halved as compared with the conventional case. Further, in this embodiment, the erase pulse is applied immediately before the liquid crystal element is selected, but the erase pulse does not have to be issued immediately before the selection period, and the erase pulse may be applied some time before the selection period. May be.

Embodiment 24 This embodiment is also a driving method utilizing the threshold characteristic of the ferroelectric liquid crystal as shown in FIGS. 82 (a) and (b).

FIG. 69 is a block diagram showing a specific circuit that realizes the drive waveforms in this embodiment, and 691 is a frame signal.
Reference numeral 92 is a polarity switching signal. The transmission gate 111 is switched by the signals of 691 and 692 to switch the voltages of V ₁ , -V ₂ , -V ₇ , -V ₈ , -V ₃ and -V ₆ to select the odd scan electrode selection waveform 694. And even scan electrode selection waveform 695
And a scan electrode non-selected waveform 696 is created.

Further, the transmission gate 111 is switched by the signals of 691, 692 and the clock pulse 693 to switch the voltage of -V ₂ , -V ₄ , -V ₅ , -V ₇ to switch the signal electrode ON waveform 697 and the signal electrode. Making off waveform 698.

The timing chart of these waveforms is shown in FIG. First
70 Fig. 694, 695, 696, 697, 698 waveforms are input to the drive circuit of Fig. 81. 694 is 8101 and 695 is 8102, 696 is 8103 and 697.
8105 and 698 are connected to 8105, respectively. And
FIG. 81 shows the second embodiment according to each signal of 117, 118, 119, 120, 121.
In the same operation as in 3, the odd scan electrode waveform in FIG.
2 even scan electrode waveforms and 713 signal electrode waveforms are created and applied to the liquid crystal element. The composite waveform is shown at 714. The drive conditions of this drive waveform are as follows.

In operation of the pixel liquid crystal elements for the FIG. 81 8111, in the erase pulses during the first 71 Fig t ₀₄ is applied immediately before the odd frame, in the combined voltage of the scanning electrode waveform and 713 of the signal electrode waveform 711 A voltage pulse of │-V ₈ + V ₂ |> | Vsat ₂₂ | is always applied to erase the previous memory state of the liquid crystal element to turn it off, and t ₁₁ is an odd-frame selection period and the signal electrode is applied to the signal electrode. Depending on whether the applied waveform is an on waveform or an off waveform, select whether the combined voltage with the scan electrode waveform is the waveform shown by 821 in FIG. 82 or the waveform shown by 822. The waveform shown indicates that the liquid crystal element is in the ON state, and the waveform indicated by 822 remains in the OFF state. Then, in the non-selection period, the scanning electrode waveform 711 is applied with the voltages −V ₃ and −V ₆ alternately, and in the composite waveform with the signal electrode waveform 713,
As shown by 14, since only a voltage whose absolute value is smaller than the threshold voltage is always applied to the liquid crystal element, the written state is maintained during t ₁₁ . Further, when writing data to the liquid crystal element during the selection period t _11, At the same time, then the liquid crystal element to be selected, since the scan electrodes waveform indicated by 712 is applied, and between t ₀₄ Is applied with a reverse polarity erase pulse to erase the previous memory state and turn it on. Next, regarding the even frames, the erase pulse is applied during the immediately preceding t ₁₄ and the voltage pulse of (V ₁ + V ₇ )> Vsat ₂₁ is applied with the polarity opposite to that at t ₀₄ immediately before the odd frame. and is turned on to erase the previous memory state of the liquid crystal element, in the selection period between t _21, or waveforms applied to the signal electrode is on waveform, Yotsute on whether the oFF waveform,
Select whether the combined voltage with the scanning electrode waveform is the waveform indicated by 821 or the waveform indicated by 822 in FIG. 82. If the waveform indicated by 821, the liquid crystal element is in the off state, and if the waveform indicated by 822 is the on state. Will remain. Then, during the non-selection period, the state that is written during t ₂₁ is maintained as in the odd frame.
Further, while writing data to the liquid crystal element during the selection period t ₂₁ , the liquid crystal element selected next at the same time is
Since the scan electrode waveform indicated by 712 is applied, an erase pulse having a polarity opposite to that during t ₁₄ is applied to erase the previous memory state and turn it off. Thus, at the same time as writing data to the liquid crystal element, the erase pulse is applied to the liquid crystal element selected next, and moreover, in the liquid crystal element selected in the odd number and the liquid crystal element selected in the even number. ,
Since the polarity of the erase pulse applied and the polarity of the selection pulse are opposite, the selection period can be halved as compared with the conventional case.
Further, it is a driving method in which the voltage applied to the scan electrodes can be lowered.

In this embodiment, the erase pulse is applied immediately before selecting the liquid crystal element, but the erase pulse does not have to be issued immediately before the selection period, and even if the erase pulse is applied some time before the selection period. Good.

Twenty-Fifth Embodiment FIG. 72 is a block diagram showing a specific circuit for realizing the drive waveforms in this embodiment. 721 is a frame signal, 7
22 is a clock signal. The transmission gate 111 is switched by the signals of 721 and 722 so that V ₁ ,
V _2, -V _3, scanning by switching the voltage of -V ₄ electrode selecting waveform 725
Is making. Further, the signal electrode on waveform 726 and the signal electrode off waveform 727 are created by switching the voltages V ₅ and −V ₅ .
The timing chart of these waveforms is shown in FIG. 73. First
73 Input the signals of 725, 726, 727 to the drive circuit of FIG. 81, and input 725 for 8101, 8102, 726 for 8105, 727 for 8104, 81
03 is connected to 0 volt respectively. FIG. 81 shows scan electrode data, which is transferred to the scan electrode side shift register 115 by the shift clock 120 and sequentially outputs a selection signal for each scan line. The selection signal causes the transmission gate 111 to switch to form the scan electrode waveform 8107. FIG. 81 shows signal electrode data, which is transferred to the signal electrode side shift register 114 by the shift clock 118, and when the data for one scanning line is transferred, the latch circuit of 116 is sent by the latch signal of 119. Latch on. With this latch output, the transmission gate of 111 is switched, and the signals of 8104 and 8105 are switched to form the signal electrode waveform of 8106. The waveforms of 8107 and 8106 and this composite waveform are shown in the timing chart of 714, 742 and 743 of FIG. The drive conditions of this drive waveform are as follows.

When the pixel of FIG. 81 8111 describing the operation of the liquid crystal element during the first 74 Fig t ₁₁ is the selection period of the odd frame, t
_An erase pulse is applied between _{14 and} a voltage pulse having an absolute value larger than the negative saturation voltage is applied to the liquid crystal element, which erases the previous memory state and turns off. If the write pulse is generated during t ₁₅ and the signal electrode waveform is an on waveform, the voltage applied to the liquid crystal element becomes a positive saturation voltage or higher, the liquid crystal element is turned on, and the signal electrode waveform is an off waveform. If so, the voltage applied to the liquid crystal element becomes equal to or lower than the positive threshold voltage, and the liquid crystal element remains in the off state. And t ₁₆
The voltage applied to the scan electrodes during this period is zero volts. In addition, the non-selection period t ₁₂ is V which has an absolute value smaller than the threshold voltage.
_Since only the voltages of ₅ and −V ₅ are applied to the liquid crystal element, the written state is maintained during t ₁₅ .

Then, in the selection period between t ₂₁ As for the selection period of the even frame, between t ₂₄ is the erase pulse, a voltage pulse of more positive saturation voltage of the voltage in the number of reverse polarity to the case of odd frame Is applied to turn on the liquid crystal element. If the write pulse and the signal electrode waveform are on waveforms during t _25, the voltage applied to the liquid crystal element has an absolute value smaller than the negative threshold voltage, and the liquid crystal element remains on while erased. When the signal electrode waveform is off, the voltage applied to the liquid crystal element is a voltage pulse having an absolute value larger than the negative saturation voltage, and the liquid crystal element is turned off. The voltage applied to the scan electrodes during t ₂₆ is zero volt.

Further, during the non-selection period t ₂₂ is the same as in the case of the odd frame, to hold the state written during t _25. By such driving, the pulse width of the voltage pulse applied during the non-selection period is always constant at t ₁₄ and the contrast unevenness is eliminated.

Twenty-sixth Embodiment FIG. 75 is a block diagram showing a specific circuit for realizing the drive waveforms in this embodiment. 751 is a frame signal, 7
52 is a clock signal. The transmission gate 111 is switched by the signals of 751 and 752 to generate V ₁ ,
_{V 2, -V 3, -V 6} , -V 7, by switching the voltage of -V ₈ make scanning electrode selecting waveform 755, -V _3, the scanning electrodes OFF signal 756 by switching a voltage of -V ₆ Making. _{Further, -V 2, -V 3, -V} 4,
-V ₅ , -V ₆ , -V ₇ voltage switching
7, and the signal electrode off waveform 758 is made. The timing chart of these waveforms is shown in FIG. Fig. 76 755,756,75
The 7,758 signal is input to the drive circuit in Fig. 81, and the 755 is 8101,8
102, 756 are connected to 8103, 757 is connected to 8105, and 757 is connected to 8104. 81, 117, 118, 119, 120, 121 by the same operation as in Example 25, the scan electrode waveform of FIG. 771 and the signal electrode waveform of 772 are created and applied to the liquid crystal element, and the resultant waveform is 773. Shown in. The drive conditions of this drive waveform are as follows.

When the pixel of FIG. 81 8111 describing the operation of the liquid crystal element during the first 77 Fig t ₁₁ is the selection period of the odd frame, t
_An erase pulse is applied between _{14 and} a voltage pulse having an absolute value larger than the negative saturation voltage is applied to the liquid crystal element, which erases the previous memory state and turns off. If the write pulse is generated during t ₁₅ and the signal electrode waveform is an on waveform, the voltage applied to the liquid crystal element becomes a positive saturation voltage or higher, the liquid crystal element is turned on, and the signal electrode waveform is an off waveform. If so, the voltage applied to the liquid crystal element becomes equal to or lower than the positive threshold voltage, and the liquid crystal element remains in the off state. And t ₁₆
The voltage applied to the scan electrode during this period is −V ₃ . Further, in the non-selection period t ₁₂ , the scan electrode waveform 771 is applied with the voltages −V ₃ and −V ₆ alternately, and in the combined waveform with 772, the absolute value is always more than the threshold voltage as shown by 773. Since only a small voltage of is applied to the liquid crystal element, the state is maintained during t ₁₅ . Next, looking at the even frame, in the selection period between t _21, between t ₂₄ is the erase pulse, the time of the odd frames positive saturation voltage higher than the pulse of opposite polarity is applied to the liquid crystal The element is turned on. If the write pulse is generated during t ₂₅ and the signal electrode waveform is an on-waveform, the voltage applied to the liquid crystal element has an absolute value smaller than the negative threshold voltage, and the liquid crystal element remains erased. When the signal electrode waveform is turned on and the signal electrode waveform is off, a voltage pulse whose absolute value is larger than the negative saturation voltage is applied to the voltage applied to the liquid crystal element, and the liquid crystal element is turned off. The voltage applied to the scan electrode during t ₂₆ is −V ₆ .

Also, during the non-selection period t ₂₂ , t ₂₅ as in the odd frame.
Hold the state between.

In the case of such driving, the composite waveform applied to the liquid crystal element is the same as that in the twenty-fifth embodiment, but the driving method in which the voltage applied to the scan electrodes can be lowered.

Example 27 FIG. 83 shows an effect diagram of holding a memory state by an AC bias. V is the voltage applied to the liquid crystal element, and I is the transmission state of the liquid crystal element. When the voltage of V ₁ is applied to the liquid crystal element and it is in the state of I ₁ , and then the applied voltage is 0 volt, the liquid crystal element gradually deteriorates from the state of I ₁ to the memory of I _{5 as} shown by the dotted line. Is falling. However, by applying an AC bias, the poor memory property can be improved and the state of I ₃ can be maintained. First
FIG. 78 is a block diagram showing a concrete circuit for realizing the drive waveform of this embodiment utilizing the effect of this AC bias.
781 is a frame signal and 782 is a polarity switching signal.
Yotsute the signal of 781 and 782, and switching-trans honey Chillon gate _{111, V 2, V 3,} -V 4, by switching the voltage of -V ₅ make scanning electrode selecting waveform 784, Yotsute to 783 signals , V ₁ , -V ₆ voltage is switched to scan electrode non-selection waveform 785
Is making. Further, the signal electrode on waveform 786 and the signal electrode off waveform 787 are created by switching the voltages V ₇ and −V ₈ . The timing chart for these waveforms is shown in FIG. The signals of 784, 785, 786, and 787 in Fig. 79 are input to the drive circuit in Fig. 81. 784 is 8101, 8102, 785 is 8103, and 786 is 8105.
, And 787 connect with 8104, respectively. FIG. 81 shows scan electrode data, which is transferred to the scan electrode side shift register 115 by the shift lock 120 to sequentially output a selection signal for each scanning line, and the transmission gate 111 is switched by this selection signal. Then, 8107 scan electrode waveforms are created. FIG. 81 shows the signal electrode data, which is transferred to the signal electrode side shift register 114 by the shift clock 118 and latched to the latch circuit 116 by the latch signal 119 when the data for one scanning line is transferred. , The output of this latch is used to switch the transmission gate 111 to switch the signals of 8104 and 8105.
The signal electrode waveform of is made. Fig. 80 shows the timing chart of the waveforms of 8107 and 8106 and the composite waveform of these waveforms.
801, 802, 803. The drive conditions for this waveform are as follows.

The operation of the liquid crystal element in the pixel shown in FIG. 81 in FIG. 81 will be described. The period during t ₁₁ in FIG. 80 is an odd frame selection period, and during t _{14 in} this period is an erase pulse, which is an absolute value greater than the negative saturation voltage. A large voltage pulse is applied to erase the previous memory state and turn it off. If the write pulse is generated during t ₁₅ and the signal electrode waveform is an on waveform, a voltage pulse of a positive saturation voltage or higher is applied to the liquid crystal element to turn on the liquid crystal element, and the signal electrode waveform is an off waveform. If so, a voltage pulse equal to or lower than the correct threshold voltage is applied to the liquid crystal element, and the liquid crystal element remains in the off state. And
During t ₁₂ , the high-frequency AC bias is applied during the non-selection period. The frequency and voltage of this high-frequency AC bias are at the marginal frequency and voltage at which the liquid crystal element can respond. The frequency is several KHz to several 100 KHz, and the voltage is several tens of volts. The memory bias of the liquid crystal element is improved by the AC bias in the non-selection period, and the data is held. Next, looking at the even frame, in the selection period between t _21, at the erase pulse between t ₂₄ in this period, the voltage pulse over opposite polarity positive saturation voltage than when the odd-numbered frame is applied Then, the liquid crystal element is turned on. If the write pulse is generated during t ₂₅ and the signal electrode waveform is an ON waveform, a voltage pulse whose absolute value is smaller than the negative threshold voltage of the liquid crystal element is applied and the liquid crystal element remains in the ON state, When the electrode waveform is an off waveform, the liquid crystal element is applied with a voltage pulse whose absolute value is larger than the negative saturation voltage, and the liquid crystal element is turned off. Then, during the non-selection period, the memory state is held by the high frequency AC bias as in the case of odd frames. In each of the above-described embodiments, the driving method in the binary display has been described, but it is possible to drive the gradation display in the same manner, and the waveform applied to the scanning electrode may be the same as that in the above-mentioned embodiment. The voltage applied to the signal electrode may be changed according to the gradation data, and the voltage applied to the liquid crystal element during the write pulse may be changed between the threshold voltage and the saturation voltage. Further, gradation display can also be performed by changing the pulse width of the signal electrode waveform according to the gradation data.

〔The invention's effect〕

As described above, according to the present invention, the pulse width dependency peculiar to the ferroelectric liquid crystal element is fully taken into consideration, and the liquid crystal always has an average value of zero regardless of the selection content of the pixel and the multiplicity. Since the voltage pulse is applied as described above, it is possible to prevent deterioration of the liquid crystal element due to a direct current component and maintain good light transmission characteristics for a long period of time. Further, the application is not limited to the display element, and the application is also possible to an electronic shutter, a polarizer and the like.

[Brief description of drawings]

FIGS. 1 (a) and 1 (b) are diagrams showing an arrangement state of molecules of a ferroelectric liquid crystal. FIG. 2A is a sectional view showing an example of a liquid crystal element used in each example of the present invention. FIG. 2B is a diagram showing an electrode structure of the liquid crystal element shown in FIG. FIG. 3 is a diagram showing the relationship between the drive waveform and the light transmission characteristic shown in the first embodiment of the present invention. FIG. 4 is a diagram showing an example of a specific circuit for realizing the drive waveform shown in FIG. FIG. 5 is a timing chart showing signal waveforms at various points in the circuit shown in FIG. FIG. 6 is a diagram showing the relationship between the drive waveform and the light transmission characteristic shown in the second embodiment of the present invention. FIG. 7 is a diagram showing an example of a specific circuit for realizing the drive waveforms shown in FIG. FIG. 8 is a timing chart showing signal waveforms at various points in the circuit shown in FIG. FIG. 9 is a diagram showing the relationship between the drive waveform and the light transmission characteristics shown in the third embodiment of the present invention. FIG. 10 is a diagram showing an example of a concrete circuit for realizing the drive waveforms shown in FIG. FIG. 11 is a timing chart showing signal waveforms at various points in the circuit shown in FIG. FIG. 12 is a diagram showing the relationship between the drive waveform and the light transmission characteristic shown in the fourth embodiment of the present invention. FIG. 13 is a diagram showing an example of a concrete circuit for realizing the drive waveforms shown in FIG. FIG. 14 is a timing chart showing signal waveforms at various points in the circuit shown in FIG. FIG. 15 is a diagram showing the relationship between the drive waveform and the light transmission characteristics shown in the fifth embodiment of the present invention. FIG. 16 is a diagram showing an example of a specific circuit for realizing the drive waveforms shown in FIG. FIG. 17 is a timing chart showing signal waveforms at various points in the circuit shown in FIG. FIG. 18 is a diagram showing the relationship between the drive waveform and the light transmission characteristics shown in the sixth embodiment of the present invention. FIG. 19 is a diagram showing an example of a concrete circuit for realizing the drive waveforms shown in FIG. FIG. 20 is a timing chart showing signal waveforms at various points in the circuit shown in FIG. FIG. 21 is a diagram showing the relationship between the drive waveform and the light transmission characteristics shown in Embodiment 7 of the present invention. FIG. 22 is a diagram showing an example of a specific circuit for realizing the drive waveforms shown in FIG. FIG. 23 is a timing chart showing signal waveforms at various points in the circuit shown in FIG. FIG. 24 is a diagram showing the relationship between the drive waveform and the light transmission characteristics shown in Example 8 of the present invention. FIG. 25 is a diagram showing an example of a concrete circuit for realizing the drive waveforms shown in FIG. 24. FIG. 26 is a timing chart showing signal waveforms at various points in the circuit shown in FIG. FIG. 27 is a diagram showing the relationship between the drive waveform and the light transmission characteristics shown in Example 9 of the present invention. FIG. 28 is a diagram showing an example of a specific circuit for realizing the drive waveforms shown in FIG. 27. FIG. 29 is a timing chart showing signal waveforms at various points in the circuit shown in FIG. 28. FIG. 30 is a diagram showing the relationship between the drive waveform and the light transmission characteristics shown in Example 10 of the present invention. FIG. 31 is a diagram showing an example of a concrete circuit for realizing the drive waveforms shown in FIG. FIG. 32 is a timing chart showing signal waveforms at various points in the circuit shown in FIG. FIG. 33 is a diagram showing the relationship between the drive waveform and the light transmission characteristics shown in Example 11 of the present invention. FIG. 34 is a diagram showing an example of a specific circuit for realizing the drive waveforms shown in FIG. 33. FIG. 35 is a timing chart showing signal waveforms at various points in the circuit shown in FIG. 34. FIG. 36 is a diagram showing the relationship between the drive waveform and the light transmission characteristics shown in Embodiment 12 of the present invention. FIG. 37 is a diagram showing an example of a concrete circuit for realizing the drive waveforms shown in FIG. 36. 38 is a timing chart showing signal waveforms at various points in the circuit shown in FIG. 37. FIG. 39 is a diagram showing the relationship between the drive waveform and the light transmission characteristics shown in Example 13 of the present invention. FIG. 40 is a diagram showing an example of a specific circuit for realizing the drive waveforms shown in FIG. 39. FIG. 41 is a timing chart showing signal waveforms at various points in the circuit shown in FIG. FIG. 42 is a diagram showing the relationship between the drive waveform and the light transmission characteristics shown in Embodiment 14 of the present invention. FIG. 43 is a diagram showing an example of a concrete circuit for realizing the drive waveforms shown in FIG. 42. FIG. 44 is a timing chart showing signal waveforms at various points in the circuit shown in FIG. 43. FIG. 45 is a diagram showing an example of a specific circuit for realizing the driving waveform shown in the fifteenth embodiment of the present invention. 46 is a diagram showing the relationship between the timing chart of the signal waveform and the drive waveform at each point of the circuit shown in FIG. 45 and the light transmission characteristics. FIG. 47 is a diagram showing an example of a concrete circuit for realizing the driving waveform shown in the sixteenth embodiment of the present invention. 48 is a timing chart showing signal waveforms at various points in the circuit shown in FIG. 47. FIG. 49 is a diagram showing the relationship between the drive waveform and the light transmission characteristics shown in Example 16 of the present invention. FIG. 50 is a diagram showing an example of a concrete circuit for realizing the driving waveform shown in the seventeenth embodiment of the present invention. 51 is a diagram showing the relationship between the timing chart of the signal waveform and the drive waveform and the light transmission characteristics at each point of the circuit shown in FIG. FIG. 52 is a diagram showing an example of a specific circuit for realizing the drive waveforms shown in Embodiment 18 of the present invention. FIG. 53 is a timing chart showing signal waveforms at various points in the circuit shown in FIG. FIG. 54 is a diagram showing the relationship between the drive waveform and the light transmission characteristics shown in Example 18 of the present invention. FIG. 55 is a diagram showing an example of a specific circuit for realizing the drive waveforms shown in Embodiment 19 of the present invention. FIG. 56 is a diagram showing the relationship between the timing chart of the signal waveform and the drive waveform at each point of the circuit shown in FIG. 55 and the light transmission characteristics. FIG. 57 is a diagram showing an example of a specific circuit for realizing the drive waveforms shown in Embodiment 20 of the present invention. FIG. 58 is a timing chart showing signal waveforms at various points in the circuit shown in FIG. 57. FIG. 59 is a diagram showing the relationship between the drive waveform and the light transmission characteristics shown in Embodiment 20 of the present invention. FIG. 60 is a diagram showing an example of a specific circuit for realizing the drive waveforms shown in Embodiment 21 of the present invention. FIG. 61 is a timing chart showing signal waveforms at various points in the circuit shown in FIG. FIG. 62 is a diagram showing the relationship between the drive waveform and the light transmission characteristics shown in Embodiment 21 of the present invention. FIG. 63 is a diagram showing an example of a specific circuit for realizing the drive waveforms shown in Embodiment 22 of the present invention. 64 is a timing chart showing signal waveforms at various points in the circuit shown in FIG. 63. FIG. 65 is a diagram showing the relationship between the drive waveform and the light transmission characteristics shown in Example 22 of the present invention. FIG. 66 is a diagram showing an example of a specific circuit for realizing the drive waveforms shown in Embodiment 23 of the present invention. 67 is a timing chart showing signal waveforms at various points in the circuit shown in FIG. 66. FIG. 68 is a diagram showing the relationship between the drive waveform and the light transmission characteristics shown in Embodiment 23 of the present invention. FIG. 69 is a diagram showing an example of a specific circuit for realizing the drive waveforms shown in Embodiment 24 of the present invention. 70 is a timing chart showing signal waveforms at various points in the circuit shown in FIG. 69. FIG. 71 is a diagram showing the relationship between the drive waveform and the light transmission characteristics shown in Embodiment 24 of the present invention. FIG. 72 is a diagram showing an example of a specific circuit for realizing the drive waveforms shown in Embodiment 25 of the present invention. FIG. 73 is a timing chart showing signal waveforms at various points in the circuit shown in FIG. 72. FIG. 74 is a diagram showing the relationship between the drive waveform and the light transmission characteristics shown in Example 25 of the present invention. FIG. 75 is a diagram showing an example of a concrete circuit for realizing the driving waveform shown in the 26th embodiment of the present invention. FIG. 76 is a timing chart showing signal waveforms at various points in the circuit shown in FIG. 75. FIG. 77 is a diagram showing the relationship between the drive waveform and the light transmission characteristics shown in Example 26 of the present invention. FIG. 78 is a diagram showing an example of a specific circuit for realizing the drive waveforms shown in Embodiment 27 of the present invention. 79 is a timing chart showing signal waveforms at various points in the circuit shown in FIG. 78. FIG. 80 is a diagram showing the relationship between the drive waveform and the light transmission characteristics shown in Example 27 of the present invention. FIG. 81 is a diagram showing an example of a drive circuit used in each embodiment of the present invention. 82 (a) and 82 (b) are views showing changes in the light transmission characteristics depending on the waveform of the applied voltage. FIG. 83 is a diagram showing the relationship between the drive waveform and the light transmission characteristics when an AC bias voltage is applied. 11,12 ...... Substrate 13 ...... Scanning electrode 14 ...... Signal electrode 15 ...... Alignment film 16 …… Ferroelectric liquid crystal 17,18 …… Polarizing plate 19 …… Sealant 111 …… Transmission gate 112 …… Flip flop 113 …… Liquid crystal element 114 …… Signal electrode side shift register 115 …… Scan electrode side shift register 116 …… Latch circuit 117 …… Signal electrode data 118 …… Signal electrode shift clock 119 …… Latch signal 120 …… Scan electrode shift clock 121 …… Scan electrode data

 ─────────────────────────────────────────────────── ─── Continuation of front page (31) Priority claim number Japanese Patent Application No. Sho 61-45868 (32) Priority date Sho 61 (1986) March 3 (33) Priority claim country Japan (JP) (56) References JP-A-60-173591 (JP, A) JP-A-61-52630 (JP, A) JP-A-61-230197 (JP, A)

Claims (1)

[Claims] 1. A method for driving a liquid crystal element, wherein a liquid crystal element having a liquid crystal having a memory property sandwiched between a substrate having a scanning electrode group and a substrate having a signal electrode group is subjected to multiplex driving by line-sequential scanning, The scanning electrode group is supplied with a selection potential in a selection period and a scanning signal having a non-selection potential in a non-selection period, and the signal electrode group is supplied with a data signal for display state selection every selection period, At least one voltage pulse equal to or higher than the saturation value of the liquid crystal display element is applied to the liquid crystal for aligning the molecules of the liquid crystal in a predetermined alignment direction during the selection period or in the non-selection period immediately before the selection period, and thereafter. A voltage pulse for setting the molecules of the liquid crystal in the predetermined alignment direction corresponding to the display state is applied to the liquid crystal within the selection period, and the intermediate potential of the data signal is set to the reference potential. Then, the scanning signal is composed of a plurality of voltage pulses that are positive and negative with respect to the reference potential, and within a predetermined period including the selection period and the non-selection period that follows, an integrated value of positive voltage pulses. And the integrated value of the negative voltage pulse are different, and
The polarities of the positive and negative voltage pulses are inverted in two consecutive predetermined periods, and the data signal is composed of a plurality of voltage pulses that are positive and negative with respect to the reference potential,
The integral value of the positive voltage pulse and the integral value of the negative voltage pulse are set equal to each other within the predetermined period, and the average value of the voltage applied to the liquid crystal is set to zero within the two predetermined periods. A method for driving a liquid crystal element, comprising: