JPS6167836A - Driving method of liquid crystal element - Google Patents

Abstract

PURPOSE:To obtain rapid response and a memory effect by forming a specific auxiliary signal applying period after selecting and applying an information signal to a signal electrode group synchronously with the application of a scanning signal to a selected scanning electrode out of a scanning electrode group prior to the selection and application of the succeeding information signal. CONSTITUTION:To drive a liquid crystal element 31 having a matrix type electrode structure consisting of the scanning electrode group 32 and the signal electrode group 33 and optically modulating a bistable liquid crystal containing dichromic coloring matters arranged between the electrodes 32 and 33 by selecting and applying scanning signals to the electrode group 32 successively and periodically and selecting and applying information signals to the electrode group 33 synchronously with the scanning signals, an information signal is selected and applied to the electrode group 33 synchronously with the application of a scanning signal to a selected scanning electrode 31-Sn out of the electrode group 32 and then an auxiliary signal applying period for applying a signal different from the information signal selected and applied to the electrode group 33 is formed prior to the operation for selecting and applying the succeeding information signal to the electrode group 33 synchronously with the scanning signal applied to the scanning electrode 32-Sm to be selected successively. This driving method of the liquid crystal element makes it possible to obtain blight display without the generation of the cross talk.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for driving an optical modulation element such as a liquid crystal element, and more particularly to a time division driving method for a liquid crystal element used in an optical modulation element such as a display element or a shutter array.

Conventionally, a liquid crystal display element has a scanning electrode group and a signal electrode group configured in a matrix, and a liquid crystal compound is filled between the electrodes to form a large number of pixels to display images or information.
well known.

The driving method for this display element is as follows:
Time-division driving is adopted in which an address signal is selectively applied periodically and a predetermined information signal is selectively applied in parallel to a group of signal electrodes in synchronization with the address signal, but this display element and its driving method are However, it had major and fatal flaws as described below.

That is, it is more elegant to increase the pixel density or, for A, to make the screen larger. Among conventional liquid crystals, most of them are practically used as display elements, for example, M, 8J, because of their relatively high response speed and low power consumption.
by hadt and W, HISlfr14'r1, ”
AppHea PhygiCF4 Letters
”, Vol t44 (1?71.2.15),
P, 127 Cape 12B's "voltage Dspen"
dent 0ptical Activity of
aTwist@a Nematia Liquid C
T I (twisted
This type of liquid crystal has a positive dielectric anisotropy in the absence of an electric field, and has a structure in which the molecules of the nematic liquid crystal are twisted in the thickness direction of the liquid crystal layer (helical structure). The liquid crystal molecules form a structure in which they are arranged parallel to each other on both electrode surfaces. On the other hand, when an electric field is applied, nematic liquid crystals with positive dielectric anisotropy are aligned in the direction of the electric field, resulting in optical modulation.

When a display element is constructed with a matrix electrode structure using this type of liquid crystal, the area where both the scanning electrode and the signal electrode are selected (selected point) has a threshold value greater than or equal to the threshold required to align the liquid crystal molecules perpendicular to the electrode surface. A voltage is applied to the area where neither the scanning electrode nor the signal electrode is selected (non-selected point), and thus the liquid crystal molecules maintain a stable alignment parallel to the electrode surface. By arranging linear polarizers above and below such a liquid crystal cell in a cross-niffle relationship with each other, light does not pass through selected points, but light passes through non-selected points, making it possible to use it as a bidirectional element. becomes. However, when a matrix electrode structure is configured, there is a region where the scan 'flt pole is selected and the signal electrode is not selected, or an area where the scan electrode is not selected and the signal electrode is selected (where n"half selected point"). ) K is also subject to a finite electric field. If the difference between the voltage applied to the selected point and the voltage applied to the half-selected point is sufficiently large, and the voltage required to align liquid crystal molecules perpendicular to the electric field is set to an intermediate voltage fK, then the display element is working normally. However, in this method, when the number of scanning lines (N) is increased, the time during which an effective electric field is applied to one selected point (duty ratio) when scanning the entire screen (one frame) is 1 It will decrease at a rate of . For this purpose 1〈9
The effective voltage difference between the selected point and the non-selected point K when performing return scanning becomes smaller as the number of scanning lines increases, and as a result, a decrease in image contrast and crosstalk are likely to be avoided. This is a drawback. This kind of development is
Temporal accumulation of liquid crystals that do not have a bistable state (the stable state is when the liquid crystal molecules are aligned horizontally with respect to the electrode surface, and they are aligned vertically only while an electric field is effectively applied). Avoidance is essentially a ubiquitous problem that arises when driving using effects (that is, scanning back and forth). In order to improve this point, voltage averaging method, dual-frequency drive method, multiplex IJ box method, etc. have already been proposed, but all of these methods are insufficient, and it is difficult to increase the screen size of display elements and increase the At present, the increase in density has reached a plateau because the number of scanning lines cannot be increased by an amount of light.

An object of the present invention is to provide a novel optical modulation element, particularly a method for driving a liquid crystal element, which solves all the problems of conventional liquid crystal display elements as described above.

Another object of the present invention is to provide a method for driving a liquid crystal element having high-speed response and memo IJ-effect.

Another object of the present invention is to provide a method for driving a liquid crystal device having a high density of pixels.

Furthermore, another object of the present invention is to provide a method for driving a liquid crystal element that does not generate crosstalk and can form a bright display.

The method for driving an optical modulation element of the present invention was developed to achieve the above-mentioned object, and more specifically, it has a matrix electrode structure having a scanning electrode group and a signal electrode group,
Periodically selectively applying scanning signals to the scanning electrode group,
By selectively applying an information signal to the signal electrode group in synchronization with the scanning signal, optical modulation of the bistable liquid crystal having a dichroic dye arranged between the scanning electrode group and the signal electrode group is achieved. A driving method for four liquid elements, comprising: selectively applying an information signal to the signal electrode group in synchronization with a scanning signal applied to a selected scanning electrode among the scanning electrode group;
In addition, before selectively applying the next information signal to the signal electrode group in synchronization with the scan signal applied to the next selected scan electrode, a signal different from the information signal selectively applied to the previous signal electrode group is applied. It is characterized by having an auxiliary signal application period.

Details of the specific example will be explained later with reference to the drawings.

The optical modulating substance used in the driving method of the present invention takes either the first optically stable state or the [4c2] optically stable state together with the dichroic dye depending on the applied electric field.
That is, a substance having a bistable state with respect to an electric field, particularly a liquid crystal having such a property, is used.

As a liquid crystal having bistability that can be used in the driving method of the present invention, a chiral smectic liquid crystal having ferroelectricity is most preferable. i, T.O.
σRNAL DFXPHYS Engineering 0URLT! :TTI!
! R8″36 (L-69) 1975, “Fer
roelectricLiquid Crystals
J: AppljlrL Pb7siceL
6t-tars' 56 (14) 1980, '8
ubmicr.

5econcL B1-5tab:La 1! ! ]−
electrooptic 8witchingin L
iqui4 Crystals J; “Solid State Physics”
16 (141) 19 No. 1 "Liquid Crystal", etc., and the ferroelectric liquid crystal disclosed in these can be used in the present invention.

More specifically, examples of ferroelectric liquid crystal compounds used in the method of the present invention include decyloxybenzylidene-y-amino-2-methylbutylcinnamate (DOBAMB○).
, hexyloxypenzylidene:p'-amino-2-
Chloroprovir sinname) (HOBACPC) and 4-o-(2-methyl)~butyl resol cylidene-4
'-octylaniline (MBRA8) and the like.

These liquid crystals may be mixed or mixed together.
Alternatively, it may be mixed with other smectic liquid crystals or fresheric (chiral nematic) liquid crystals.

Representative examples of dichroic dyes used in the present invention are as follows.

a7. o@nx=N-@)-x=n-@7-<°・8・
8. 8S °°°“H, 0, 8■>N=-@-(c door-°'8゛\
C2H5 10・α>N=N−@−x=u−@−x−,.

6□■.

0, MX@, 2,) N=N combination N-Ikuku giant εΣ-N 102H5t In addition to these dichroic dyes, the present invention also includes at least one chromophore moiety and at least one optically active moiety. Helichromic fk dichroic dyes contained in a single molecule can be used. Specific chromophores include azo, azo-stilbene, benzothiazolylpolyazo, azomethine, methine, merocyanine, anthraquinone, methylalkoxy,
Tetrazine, oxadiazine, carbazole-azo, etc. can be used. In addition, the optically active moiety is an organic group having an asymmetric carbon atom.

Isomorphically, (+1-2-methylalkyl group, ←)-3-
Methylalkyl group, (+l -2-methylalkoxy M
, (@-5-methylalkoxy group, (4))-S-methylcyclohexyl, f+l-α-methylbenzyl, (
+)-2-methylbutylbiphenyl, f+1-2-methylbutylphenylthio, -(→-9.N-2-71 methylbutylaminonaphthalene, etc.) Typical helichromic dichroic dyes are shown below. These synthetic methods are disclosed in JP-A-59-95777.

These dichroic dyes have a 0.1
"w1G" is dissolved in the smectic liquid crystal in a range of 1 to 5 times, preferably 1 to 5 times.

When constructing an element using these materials, the liquid crystal compound is
*The temperature is like this! I! In order to maintain the AK, the element can be supported by a steel block or the like in which a heater is embedded, if necessary.

FIG. 1 schematically depicts an example of a strongly conductive liquid crystal cell. 14 and 14' are engineering n, O,, 13nO.

It is a substrate (glass plate) coated with transparent electrodes such as undium-Tin o Xtae, and a dichroic dye is sealed therebetween. # indicated by thick bar
! 13 represents a liquid crystal molecule oriented together with a dichroic dye, and this liquid crystal molecule 15 has a Kffl polar moment (on P) 1a in a direction orthogonal to the molecule. When a voltage higher than a certain threshold is applied between the electrodes on the substrates 14 and 14', the helical structure of the liquid crystal molecules 13 is unraveled.
The alignment direction of the liquid crystal molecules 15 can be changed so that all of the dipole moment) (P↓) 14 are oriented in the direction of the electric field.

The liquid crystal molecules 13 have an elongated shape and exhibit refractive anisotropy in the long axis direction and the short axis direction. It is easily understood that the liquid crystal optical modulation element has optical properties that change depending on the thickness of the liquid crystal cell. When thinned by light (e.g. 1μ
), even when no electric field is applied, the helical structure of the KM crystal molecules with the dichroic dye separates and becomes a non-helical structure, as shown in Figure 2, and its dipole moment P or y
takes either an upward direction (24) or a downward direction (24).If an electric field source or d with a different polarity greater than a certain r4 value is applied to such a cell for a predetermined period of time as shown in the M2 diagram, the twin culm moment changes direction to upward 24 or downward 24' in response to the electric field vector of 1 field E or E',
Accordingly, the liquid crystal molecules together with the dichroic dye are aligned in either the first stable state 25 or the second stable state 23'. Therefore, so that the individual behavior is parallel to the orientation direction of the first stable state 133 or the second stable state 33',
Optical contrast can be obtained by placing one IYT element above the glass surface.

There are five advantages to using such a ferroelectric liquid crystal as an optical modulation element. The first K is that the response speed is extremely fast, and the second is that the alignment of liquid crystal molecules has a bistable state. To illustrate the second point, F! To explain using Figure 2,
When an electric field is applied, the liquid crystal molecules are aligned in the first stable tk state 23, and this state remains stable even when the electric field is turned off.

Furthermore, when an electric field X' in the opposite direction is applied, the liquid crystal molecules are oriented in the stable state Q25' of Ka2, and the orientation of the molecules is changed, but they remain in this state even after the electric field is turned off. Further, the applied electric field 8 has a constant darkness value and is barely maintained in the orientation of each wing of the force 1 and IL. This kind of response speed (
In order to realize speed and memory effect effectively, it is preferable for the cell to be as thin as possible, and in general, the cell thickness is 0.
．． 5μ to 20μ, especially 1μ to 5μ are suitable. A liquid crystal electro-optical device having a matrix electrode structure using this type of ferroelectric liquid crystal has been proposed, for example, by Clark and Ragapal in US Pat. No. 4,567,924. Fifth, only one polarizing plate is required, and the display is brighter.

Next, a specific example of a method for driving a capacitive plate crystal (an example of a ferroelectric liquid crystal) will be described with reference to FIGS. 31 to f45.

FIG. 3 is a schematic diagram of a cell 51 having an intermediate IJ electrode structure in which a dichroic dye and a ferroelectric crystal compound (not shown) are sandwiched.

32 is a scanning electrode group, and 35 is a signal electrode group.

The case where the scanning IL pole S1 is selected at the odd beginning will be described. 4 figures (lL) and 4 figures (bl is a scanning signal,
Electrical signals applied to each selected scanning electrode %'h and other scanning electrodes (unselected scanning electrodes)"?
+s*+'4...K indicates the applied electrical signal. DA (el) and FIG. 4 (FDL) are alert signals, and show electrical signals given to selected signal electrodes 1, 7, and unselected signal electrodes, respectively.

In FIG. 4 and the GS diagram, the horizontal axis represents time and the horizontal axis represents voltage, respectively. For example, when displaying a moving image, the scanning electrode group S2 is sequentially and periodically selected.

Now, r for giving the first stable state of the liquid crystal cell having bistability for a predetermined voltage application time t or t.
If the d6 value voltage is -v th and the threshold 414 voltage for providing the second stable state is +vth, the selected scan N, pole 52 (E+i)K given one-pole word is as shown in FIG. As shown in (al K), at phase (time) t>, the voltage is 2v, and at phase (time) tt, it is -2v. It is believed that by applying an electrical signal with a phase interval of You can get the following effect.

On the other hand, the other scanning electrodes r3. ~B, . . . are in a grounded state as shown in Figure 4, fb+, and the electricity is 1 and 0. Also selected signal electrode machining,.

The electric signal given to rl and gills is 14i1(clK
As shown, the three-charged electrode I is M and is not selected.
, I, is < -V as shown in Figure 4 (al).
Ir#i is set to a desired value that satisfies the following relationship.

V(7th, (57 -51 Kuichi 4th, (-4) Of each pixel when such an electrical signal is given,
For example, the voltage waveforms applied to each pixel and B in FIG. 3 are shown in body) and (tel) in FIG.

That is, at the pixel A in the selected scanning line 1, at the phase t,
The threshold value Vth, f and the i-oh 3v are applied.

Furthermore, the phase of pixel B existing on the same scanning line is t.

At , a voltage of -5V exceeding the threshold value -vth is applied. Therefore, depending on whether or not a signal electrode is selected on the selected scanning electrode line, if the signal electrode is selected, the liquid crystal molecules align the first stable QK orientation with the dichroic dye, and If not, align the orientation with the dichroic dye to 14 stable signals.

-1, 45 (c) 7(,il) On the unselected scan lines, the voltage applied to all pixels is either V or -V, and neither exceeds the threshold M7. Therefore, the molecules in each pixel other than those on the selected scanning line maintain the orientation corresponding to the signal drop WK when scanned last time without changing the orientation state. '^ When one disease is selected, the signal for that one line is written, and the signal state can be maintained until the next selection after one frame ends. Even if the number of scanning voltages increases, the actual duty ratio remains unchanged and the contrast does not deteriorate at all.

Next, let us consider the problems that may actually arise when [141] is performed as a single display. Scanning at 3rd mK? lE extreme day, ~8s... and the name? ? C%It
Among the pixels formed at the intersections of ~J,..., the pixels in the slanted part are in the "bright" state, and the pixels shown in white are in the "dark J&'IN" state.
shall correspond to Now, if we pay attention to the display above the signal electrode in Figure 3, we can see that the pixel + corresponding to the scan 1 electrode S
The pixels in Al are in the "bright" state, and all other pixels (Bl are in the "dark" state. As an example of the driving method in this case, the scanning signal and the information signal given to the signal line 3 and 14j The 61st bacterium fal is a chronological representation of the voltage applied to an amateur.

For example, when driving with K like 6ii9(al),
When the scanning signal day, is scanned, time 1. At this time, a voltage of 3V exceeding the threshold value Vth is applied to the pixel, so both pixels are in a stable state in one direction, regardless of the previous IK amount.
Light-like qK transition (switch). After that, 5t-8
, . . . , a voltage of -4 continues to be applied as shown in FIG.
, the pixel can maintain a "light" state. However, when displaying information in which a -1 signal (corresponding to "dark" in this case) is continuously given on one signal electrode, the number of scanning lines is extremely large and high-speed driving is required. Missing data shows that problems can arise when required.

Figure 7 shows DOBAMBC (7th grade) as a ferroelectric liquid crystal material.
Voltage threshold (Vth) required for switching when using 72) in the figure and HOBAOPO (71 in Figure 7)
This is a plot of the application time dependence of . In both cases, the liquid crystal thickness is 1.6μ, and the temperature is controlled at 70°C. In this case, the substrates on both sides in which the liquid crystal is to be sealed are glass plates on which ITO is vapor-deposited, and v
th, ■vth.

(=7th).

As is clear from FIG. 7, the threshold value vth is dependent on the application time, and it is understood that the application time is shorter and the slope is steeper. From this, if we take a driving method like that used in @61g (alK) and apply it to an element that has an extremely large number of scans (41) and is driven at high speed, for example, image ygA will be 8. Even if the pixel is switched to the "bright" state, a voltage of -V continues to be applied after scanning 8, so there is a risk that the pixel will be reversed to the "dark" state during the completion of scanning one screen. I understand.

As a driving form to prevent such a phenomenon, for example, the method shown in Fig. ig6 (bl) can be used.

This method does not send the scanning signal and the information signal continuously, but instead uses a predetermined time interval Δt as the auxiliary signal application period.
, and this period +i=14'l: represents R type which provides an auxiliary temperate zone where the signal electrode is grounded. During this auxiliary signal application period, the scanning electrode is also grounded, so the voltage applied between the scanning calculator and the signal electrode is 0 volts. The dependence on IC can be substantially eliminated. Therefore, it is possible to prevent the "bright" state generated in the pixel from being reversed to the "dark" state.

Moreover, the same thing can be said about other pixels.

As mentioned above, the present invention is based on the ferroelectric P! ,! Although the crystal has the characteristics shown in Figure 7, it is characterized by the fact that once written information can be maintained for a period of time until the next writing is performed. ing.

A more preferred embodiment of the present invention can be implemented by applying the signals shown in the time chart of FIG. 8 to the scanning electrodes and the signal electrode group.

V shown in Figure 8 is expressed as a predetermined voltage value appropriately determined depending on the liquid crystal material, liquid thickness, set temperature, surface treatment conditions of the substrate, etc., and the scanning signal is a ±27 alternating pulse. An information signal is sent to the signal electrode group in synchronization with the pulse,
This is a voltage of +V or -V corresponding to "bright" or "dark" information, respectively. Now, looking at the scanning signals in chronological order, day n (nth scanning electrode), 8n+, (n
A time interval Δt is provided as an auxiliary signal application period 14 while the +1st scanning voltage is selected. During this time, if an auxiliary signal with a polarity opposite to that of the signal during sn scanning is sent to the signal electrode group, the time-series signal given to each signal electrode is, for example, the 8th
The result will be as shown in the figure. That is, the auxiliary signals 1', 2', 5', 4', and 5' in FIG. 8 have polarities opposite to those of the information signals 1, 2, 5, and 4.5, respectively. For example, if we look at the voltage applied to the pixel in Figure 8 in chronological order, even if the same information signal is continuously applied to one signal electrode, the voltage actually applied to the pixel (applied) Since the voltage is alternating with a voltage lower than vth, the dependence of the voltage application time on the single value voltage in the strongly conductive liquid crystal is eliminated, and the desired (in this case, "bright") voltage formed during the first scan is eliminated. There is no worry that the information will be reversed before the next write is performed.

Figure Wc9 rat is a simplified diagram of the 1-air system factor when driving a strong TSY, A-crystalline cell in the drive mode shown in No. 8(2)K. Signals to be applied to the scan electrode group are formed by sending a clock signal (aS) generated by a clock generator to a scan electrode selector that selects a scan electrode, and by sending this to a scan electrode driver.

On the other hand, the signal (D-sensor) applied to the signal electrode group is sent from the output signal (DS) of the data generator and the clock signal (C8) to a data modulator that can form an information signal and an auxiliary signal. Further, it is supplied through a No. Kflj electrode driver.

FIG. 9 (bl is an example of a signal output by the data modulator, and corresponds to the signal shown in FIG. 8 based on the embodiment described above).

9 (el is data change for outputting the signal shown in FIG. 9 () above). ! 14e schematically shows two inverters 91 and 92, two AND circuits 9S and 94, and one OR circuit 9514.
According to m, the feeling is 1.

7g10 is another embodiment according to the gist of the present invention. That is, an example is shown in which a ±3v pulse is applied instead of the ±27 pulse applied to the selected 14F electrode used in the embodiment shown in Figure 2g8.

In order to effectively achieve the driving method of the present invention, the electrical signals applied to the scanning electrodes or the signal electrodes do not necessarily have to be simple symmetrical rectangular wave signals as explained in the above specific example. It is obvious that, for example, it is possible to drive with a sine wave or a triangular wave, provided that an effective time width is given. Also, since Vth can have different values depending on the surface treatment status of the two substrates sandwiching the liquid crystal, if the surface treatment status of the two substrates is different, the OV It is also possible to give an asymmetrical signal with respect to (ground). In addition, in this gA embodiment, only the auxiliary signal that inverts the polarity of the previous information signal is selected, but it may be one that inverts the polarity of the next information signal, ? The absolute value of EE may be different from the absolute voltage value of the information signal. Further, as an auxiliary signal, it is also possible to provide a desired signal obtained by statistically processing not only the contents of the previous information signal but also a plurality of previous information signals.

FIG. 14 is a schematic plan view of a liquid crystal-light shutter as an example of a preferable application of the driving method of the present invention. Here, 141 is a pixel, and only this part has IEs on both sides.
The poles are made of transparent material. The matrix electrode includes a scanning electrode group 142 and a signal [tl' 143 K? )It is configured.

[Brief explanation of drawings]

1 and t42 are perspective views schematically showing the optical modulation element used in the method of the present invention. The third factor is a plan view of the matrix electrode structure used in the method of the invention. 4(2)(al~(dl) is an explanatory diagram showing the electric temperate zone where matrix voltage and f1iIK are applied. !45(-~(,i) is an explanatory diagram showing the waveform of the specific voltage applied between the matrix electrodes. FIG. 6 fa) is an explanatory diagram of a time chart used in a driving method other than the present invention. FIG. Fig. 9 is an explanatory diagram of the time chart used.
)1 is the data transformer output signal (D
%M9 (fc) is an explanatory diagram showing the manner in which the data modulator output signal (DM) of FIG. 9(b) is formed. FIG. 7 is an explanatory diagram showing the dependence of voltage application time on threshold voltage in a ferroelectric liquid crystal. Figure @14 is a schematic plan view of a liquid crystal-optical display using the method of the present invention. 14.14'; Substrate 12 coated with transparent tn':
Liquid crystal molecule layer 13; Liquid crystal molecules 14; Dipole moment (P) 24; Upward dipole moment 24'; Downward dipole moment 23; First stable state 23': Second stable state 52 ('t, Sy+...):, scanning electrode group (scanning electrode) 55 (1,, engineering 2...); f band electrode group (signal electrode) patent applicant Canon Co., Ltd. j t-N m kidney ψ
C end target (Jl 9I-+
1-1 1-I @c OQ'1'
s: ψ to target 0
0 0-1111111

Claims (1)

[Scope of Claims] (1) It has a matrix electrode structure having a scanning electrode group and a signal electrode group, a scanning signal is selectively and sequentially applied periodically to the scanning electrode group, and the scanning signal is applied to the signal electrode group in sequence. A liquid crystal driving method for optically modulating a bistable liquid crystal having a dichroic dye disposed between the scanning electrode group and the signal electrode group by selectively applying an information signal in synchronization with the signal. and after selectively applying an information signal to the signal electrode group in synchronization with the scan signal applied to the scan electrode selected from the scan electrode group, and a scan signal applied to the next selected scan electrode. Driving a liquid crystal element characterized by having an auxiliary signal application period in which a signal different from the information signal selectively applied to the signal electrode group is applied before the next information signal is selectively applied to the signal electrode group in synchronization. Law. (2) The method for driving a liquid crystal element according to claim 1, wherein the bistable liquid crystal is a ferroelectric liquid crystal. (3) The method for driving a liquid crystal element according to claim 2, wherein the ferroelectric liquid crystal is a chiral smectic liquid crystal. (4) The method for driving a liquid crystal element according to claim 3, wherein the chiral smectic liquid crystal has a liquid crystal phase with a non-helical structure. (5) The chiral smectic liquid crystal has a C phase, an H phase,
The method for driving a liquid crystal element according to claim 3 or 4, wherein the liquid crystal element is in F phase, I phase or G phase. (6) The method for driving a liquid crystal element according to claim 1, wherein the dichroic dye is a helichromic dichroic dye. (7) The method for driving a liquid crystal element according to claim 1, wherein the electrical signals applied to selected scan electrodes of the scan electrode portions have different voltage phases. (8) The method for driving a liquid crystal element according to claim 1, wherein the electric signal applied to a selected signal electrode of the signal electrode group and the electric signal applied to an unselected signal electrode are at different voltages. . (9) The method for driving a liquid crystal element according to claim 6, wherein the electrical signals applied to the scan electrodes selected from the scan electrode group have phases with different voltage polarities. (10) An electric signal applied to a selected signal electrode of the signal electrode group and an electric signal applied to an unselected signal electrode have different voltage polarities.
Driving method of liquid crystal element described in section. (14) The electrical signal applied during the auxiliary signal application period has a voltage polarity different from that of the information signal applied to the signal electrode group in synchronization with the scanning signal applied to a selected one of the scanning electrodes. A method for driving a liquid crystal element according to claim 1.