JP2805253B2 - Ferroelectric liquid crystal device - Google Patents

Abstract

A method of driving a liquid crystal display element in which a switching element is provided for each of pixel electrodes arranged in a matrix manner and a ferroelectric liquid crystal is sandwiched between the pixel electrodes and a counter electrode includes the steps of applying a reset voltage for resetting the entire pixel to a first stable state of the ferroelectric liquid crystal across the pixel electrode and the counter electrode, partially transiting the pixel to a second stable state by a tone signal voltage having a pole opposite to that of the reset voltage, and reversing the pole of the reset voltage every predetermined period. Assuming that a state reverse ratio of the ferroelectric liquid crystal is T(V)% when the tone signal voltage is V, a tone signal voltage V1 after negative resetting and a corresponding tone signal voltage -V2 after positive resetting satisfy the following relation: T(V1) + T(V2) = 100 <IMAGE>

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a ferroelectric liquid crystal device such as a display device.

[0002]

2. Description of the Prior Art Ferroelectric liquid crystal (hereinafter referred to as FLC)
Electro-optical devices using GaN have been mainly applied to simple matrix display devices, taking advantage of their characteristics of high-speed response to an electric field and exhibiting bistability. The application of is also being considered. The feature of the active matrix FLC element is the first
Second, the scanning time (frame period) of one screen can be determined regardless of the response speed of the FLC. In the simple matrix FLC element, since the liquid crystal needs to respond within the selection time of one scanning line, the frame period cannot be reduced to (response speed of liquid crystal) × (the number of scanning lines) or less. There is a disadvantage that the frame period becomes longer as the number increases. On the other hand, the active matrix FL
In the C element, only charging / discharging of the pixel on the scanning line need be performed within one scanning line selection time, and after the selection period, the switching element of the pixel is turned off to hold the voltage applied to the liquid crystal. The response of the liquid crystal takes place within this holding time. Therefore, the frame period does not depend on the response speed of the liquid crystal, and even if the number of scanning lines increases, the frame can be operated at 33 ms used in a television.

A second feature of the active matrix FLC element is that gradation display is easy. One of the gradation display methods of the active matrix FLC element is EP284134.
The principle is that the pixel is reset to one stable state in advance, and then the charge Q is applied to the pixel electrode through the active element, whereby the second portion of the FLC is partially applied within one pixel. Is switched to a stable state. When this principle is used, assuming that the area of the portion where the switching to the second stable state occurs is a and the magnitude of the spontaneous polarization of the FLC is P _s , the charge of 2P _S · a moves by the switching. Switching to the second stable state continues until the initially applied charge Q is canceled. The area of the finally a = Q / 2P _S is second stable state. By changing Q, control of a, that is, area gradation is realized.

FIG. 7 is a sectional view of a specific example of a ferroelectric liquid crystal cell constituting such a ferroelectric liquid crystal element. This liquid crystal cell uses a TFT (thin film transistor).

In FIG. 7, a semiconductor film (amorphous silicon doped with hydrogen atoms) is formed on a substrate 70a of glass or plastic through a gate electrode 71 and an insulating film (such as a silicon nitride film doped with hydrogen atoms) 72. Film) 73 and two terminals 74 and 75 in contact with the semiconductor film 73;
5 (ITO: Indium Tin)
Oxide) 76a is formed.

Further, an insulating layer (polyimide,
A light shielding film 78 made of polyamide, polyvinyl alcohol, polyparaxylylene, SiO ₂ , or TiO ₂ ) 77a and aluminum or chromium is provided. A counter electrode (ITO: I
ndium Tin Oxide) 76b and insulating film 77
b is formed.

[0007] A ferroelectric liquid crystal 80 is sandwiched between the substrates 70a and 70b. In addition, a seal member 81 for sealing the ferroelectric liquid crystal 80 is provided around the substrates 70a and 70b.

On both sides of the liquid crystal element having such a cell structure, crossed Nicol polarizers 82a and 82b are arranged.
Polarized behind photon 82b by the reflecting plate (sheet or plate of diffuse aluminum) 83 is provided so as to be able to see the display state of the liquid crystal element observer A is the reflected light I ₁ than the incident light I ₀ I have.

In the TFT of FIG. 7, the names of the source electrode and the drain electrode corresponding to the terminals 74 and 75 refer to the case where the direction of current flow is limited to one direction. In general, an FET can operate similarly when the source and the drain are exchanged.

[0010]

According to experiments conducted by the present inventors, the area gray scale method based on the charge modulation has one problem.
There are two disadvantages. That is, the transition from the first stable state to the second stable state does not proceed until the electric charge is completely canceled as described above, but stops halfway. This is shown in FIG. FIG. 8 shows the voltage between the pixel electrodes (FIG. 8 (a)) and the transmitted light intensity (FIG. 8 (b)) when resetting and gradation display are repeated at a period of 33 ms, similar to that used in a normal television. ) Is plotted over time. The voltage shows a sharp decay immediately after the active element (for example, a TFT) is turned off, but the decay becomes extremely slow. Similarly, immediately after the active element is turned off, the intensity of the transmitted light, which changes abruptly, gradually becomes slow. That is, it can be seen that the reversal between the states progresses only very slowly or stops even though an electric field exists between the electrodes.

Due to this phenomenon, a residual DC electric field is constantly applied to the liquid crystal, and eventually causes the deterioration of the liquid crystal material. Alternatively, in a liquid crystal element having a configuration in which an insulating layer is provided between an electrode and a liquid crystal as shown in FIG. 7, impurity ions in the liquid crystal adhere to the interface of the insulating layer by a DC electric field, and
Since the electric field is generated in a direction opposite to the C electric field, it works in a direction that impairs the bistability of the FLC.

[0012] The present invention relates to a liquid crystal material or degradation of the ferroelectric liquid crystal device, and an object thereof is to provide a ferroelectric liquid crystal device <br/> that bistability is not lost.

[0013]

In this onset bright order to achieve the above object, according to an aspect of the switching element provided for each pixel electrode arranged in a matrix, the intensity and sandwiching a ferroelectric liquid crystal between the counter electrode a ferroelectric liquid crystal device, the first reset voltage for resetting to a stable state of the ferroelectric liquid crystal to all the pixels between the electrodes, and the opposite polarity to the said reset voltage, a second stable state pixel partially voltage applying means for applying switching between signal voltage Ru to transition alternately, and means for inverting the reset voltage every predetermined period, the constant cycle
Ferroelectric liquid crystal device which have the means for inverting the signal voltage
A in the ferroelectric state inversion of the liquid crystal upon application of a positive polarity signal voltages V ₁ after applying the negative polarity reset voltage T (V
₁ )% , negative signal voltage after application of positive reset voltage
The ferroelectric state inversion of the liquid crystal upon application of pressure V ₂ T
(V ₂ )%, T (V ₁ ) + T
Is the _(V 2) = satisfy 100% of the relationship.

In a preferred embodiment of the present invention,
The cycle is a scanning cycle of one screen. Also, adjacent scanning lines
Are of opposite polarity, and the first stable state is
Corresponds to the black state. Further, the signal voltage represents the gradation information.
Signal voltage.

[0015]

According to the present invention, since the polarity of the reset voltage and the polarity of the gradation signal voltage are inverted at regular intervals, it is possible to prevent a situation where a DC electric field is constantly applied to the liquid crystal.

Therefore, deterioration of the liquid crystal material and FL
It is possible to prevent a decrease in the bistability of C. Also, individual
100% first in each pixel by negative reset voltage
Signal after transition to a stable state (for example, black state)
The second stable state (white state) by T (V ₁ )% by the voltage V ₁
State) and a positive reset voltage.
Transition 100% of the element to the second stable state (white state)
Negatively charged by the signal voltage _{V 2} T _{(V 2)%} by a first after
In the case of transition to the stable state (black state),
Area ratio of the black state part and the white state part
Because the degree (display gradation) is equal, the reset voltage and
Luminance change (freedom) by switching the polarity of the signal voltage
Does not occur.

The dual drive that can be used in the driving method of the present invention
As a stable ferroelectric liquid crystal, it has ferroelectricity
Chiral smectic liquid crystal is most preferred, of which
Chiral smectic C phase (SmC^*), H phase (Sm
H^* ), I phase (SmI^*), J phase (SmJ^*), K phase (S
mK^*), G phase (SmG^*) Or F phase (SmF^*) Liquid
Crystals are suitable. About this ferroelectric liquid crystal, "LE
 JOURNAL DEPHYSIQUE LETTE
RS "36(L-69) 1975, "Ferroele
tric Liquid Crystals ";" A
Applied Physics Letters "3
6(11) 1980 "SubmicroSecond
Bistable Electric Swi
tching in Liquid Crystal
s ";" Solid state physics "16(141) 1981 "Liquid crystal" etc.
In the present invention, the incentives disclosed therein are described.
An electrically conductive liquid crystal can be used.

Specific examples of the ferroelectric liquid crystal compound used in the present invention include desyloxybenzylidene-p'-amino-2-methylbutylcinnamate (DOBAMB).
C), hexyloxybenzylidene-p'-amino-2
-Chloropropylcinnamate (HOBACPC), 4
-O- (2-methyl) butyl resorcylidene-4'-octylaniline (MBRA8) and the like.

When a liquid crystal is formed using these materials, the element is heated by a heater as necessary to maintain the liquid crystal compound in a temperature state such that the liquid crystal compound becomes a chiral smectic phase such as an SmC phase C ^* or SmHC ^* phase. It can be supported by an embedded copper block or the like.

FIG. 9 schematically shows an example of a ferroelectric liquid crystal cell.
It is what I drew. 91a and 91b, In_TwoO_Three, SnO
_TwoAlternatively, ITO (Indium Tin Oxid)
e) Substrate covered with a transparent electrode consisting of a thin film (glass)
Liquid crystal molecule layer 92 is suspended on the glass surface
SmC oriented to be straight^*Or SmH^* Etc. Kai
Larsmectic phase liquid crystal is enclosed. Shown by bold line
The line 93 represents a liquid crystal molecule.
3 is a dipole moment (P
⊥) 94 is provided. Between electrodes on substrates 91a and 91b
When a voltage higher than a certain threshold is applied to the
The helical structure is released, and the dipole moment (P モ ー メ ン ト) 94 becomes
The liquid crystal molecules 93 change the alignment direction so that they all face the electric field direction.
Can be changed. The liquid crystal molecules 93 have an elongated shape.
And exhibits refractive index anisotropy in the major axis and minor axis directions.
And thus, for example, cross each other above and below the glass surface
If a Nicol polarizer is placed, the optical characteristics depend on the polarity of the applied voltage.
Easily become a liquid crystal optical modulator with changing properties
Is done. Further, the thickness of the liquid crystal cell is made sufficiently thin (for example, 1
μm), an electric field is applied as shown in FIG.
Even when the liquid crystal molecules are not in the helical state,
And the dipole moment Pa or Pb
Is upward (arrow 104a) or downward (arrow 104a).
Take either state of b). In such a cell, FIG.
As shown in FIG.
When Eb is applied by voltage applying means (not shown),
The pole moment is the electric field vector of the electric field Ea or Eb.
Corresponding to the direction of upward 104a or downward 104b
And the liquid crystal molecules accordingly change to the first stable state 10.
5a or the second stable state 105b
Orient.

The use of such a ferroelectric liquid crystal as an optical modulation element has two advantages.

First, the response speed is extremely fast.
Another problem is that the orientation of the liquid crystal molecules has bistability. Second
If the electric field Ea is applied, the liquid crystal molecules are oriented to the first stable state 105a. This state is stable even when the electric field is turned off. When an electric field Eb in the opposite direction is applied, the liquid crystal molecules are oriented to the second stable state 105b and change the direction of the molecules, but remain in this state even after the electric field is turned off. As long as the applied electric field Ea or Eb does not exceed a certain threshold value, the respective alignment states are also maintained. In order to effectively realize such a high response speed and bistability, it is preferable that the cell is as thin as possible, and generally, 0.5 μm to 20 μm, particularly 1 μm to 5 μm is suitable. A liquid crystal-electro-optical device having a matrix electrode structure using a ferroelectric liquid crystal of this type has been proposed, for example, by Clark and Lagabal in U.S. Pat. No. 4,367,924.

According to the present invention, when an element having an FET (field effect transistor) structure such as a TFT constituting an active matrix reverses a voltage applied between a drain electrode and a source electrode, the respective elements as a drain and a source can be used. This is based on the fact that the function of the electrode normally operates as the FET in a state where the role is reversed. As an element constituting the active matrix, any element such as an amorphous silicon TFT and a polycrystalline silicon TFT can be used as long as the element has an FET structure. In addition, a switching element other than the FET structure, which can operate for both positive and negative applied voltages, for example, a bipolar transistor, can also be used. Furthermore, MIM (Metal-I
It is also possible to use a two-terminal switching element such as an nsulator (metal) or a diode.

[0024] N-type FET, the drain voltage V _D, the gate voltage V _G, the source voltage V _S, when the V _P and the threshold voltage between the gate and source, with _{V D> V S, V G} > V becomes conductive when the _S + V _P, the non-conducting state when _{V G <V S + V P} .

In the P-type FET, when V _D <V _S , the conduction state is established when V _G <V _S + V _P , and the conduction state is established when V _G > V _S + V _P.

Which terminal of the FET functions as a drain and which functions as a source, whether it is a P-type or an N-type, depends on the direction of voltage application.
That is, in the N-type, the lower voltage acts as a source, and in the P-type, the higher voltage acts as a source.

In a ferroelectric liquid crystal element, which of a “bright” state and a “dark” state with respect to positive and negative voltages applied to a liquid crystal cell is disposed above and below the cell. Polarization axes of a pair of polarizers in a crossed Nicols state,
It can be set freely according to the direction of the liquid crystal molecule long axis.

According to the present invention, the electric field applied to the liquid crystal cell is controlled by controlling the voltage between the terminals of each element of the active matrix, and the display is performed. Without being caught
This can be achieved if the potential difference between the signals is relatively maintained.

Embodiment 1 FIG. 1 shows a configuration of an FLC panel and a drive system for driving the FLC panel according to an embodiment of the present invention. In FIG. 1, reference numeral 1 denotes an active matrix drive type FLC panel using a TFT as an active element, 2 denotes an X driver including a shift register and a hold circuit, 3 denotes a Y driver including a shift register and a latch, 4
Is a timing controller, 5 is a polarity inversion circuit of a video signal, 6 is a polarity inversion circuit of a reset signal, and 7 is a switching circuit for switching between a video signal and a reset signal.

In this embodiment, as shown in FIG. 2B, the timing controller and the Y driver generate the first gate pulse and the second gate pulse slightly delayed (by Td) from the first gate pulse. This is applied to each gate line 9 in a sequential horizontal cycle. Paying attention to one line or pixel, the frame period is Tf until the next gate pulse, and the pulse in FIG. 2B corresponds to this. The outputs to the input signal line 10 to the X driver are respectively set to the negative reset voltage, the positive gray scale signal voltage, the positive reset voltage, the negative reset voltage in accordance with the timing of the gate pulse,. The operation timings of the polarity inverting circuits 5 and 6 and the switching circuit 7 are controlled so as to obtain a gradation signal voltage,... Therefore, a drive signal as shown in FIG.
Applied through T. Further, the TFT is off when no signal is applied, and the above-mentioned FL
The cancellation effect of the charge due to the spontaneous polarization P _S and C, the interelectrode voltage waveform at the pixel of interest as a capacitive load 2
(C).

In FIG. 2 (c), corresponds to the negative polarity reset. At this time, all FLCs in the pixel return to the first stable state, and during the time Td, the FLC in the entire pixel becomes the black state as shown in FIG. 3 (a). Become. Thereafter, when a charge Q (= CV ₁ , C: inter-electrode capacitance of the pixel, V ₁ : gradation signal voltage) is applied to the pixel by application of the positive polarity gradation signal (), a = Q / 2
The area (domain) corresponding to P _S is inverted to white display (FIG. 3B). At this time, the charge Q is canceled by the P _S of the FLC, so that the voltage decay 12 (FIG. 2C) occurs. Occur.
This state lasts for (Tf-Td) (where Tf >>
Td) Display gradation state. The reversal rate at this time is T
If (V ₁ ) [%], T (V ₁ ) = a / S (S: total area of the pixel), which is almost equal to the transmittance.

Next, the operation moves to the state (1). Corresponds to a positive polarity reset. At this time, all FLCs in the pixel shift to the second stable state, and as shown in FIG. Then, the charge Q (=
CV ₂₎ is applied to the pixel, the area corresponding to a = Q / 2P _S (domain) in turn is inverted to black display as shown in FIG. 3 (d). Reference numeral 14 denotes the voltage decay occurring at this time. Assuming that the reversal rate at this time is a / S = T (V ₂ ), the transmittance is 100−T (V ₂ ). Therefore, the relationship between the signal voltage and the transmittance at the time of the positive gradation signal and the time of the negative gradation signal are complementary. Therefore, for example, the relationship between the positive gradation signal V ₁ and the negative gradation signal −V ₂ for obtaining a predetermined transmittance is T (V ₁ ) + T (V ₂ ) = 100. These steps and are repeated to display the FLC panel. In particular, if the sum of the time Td required for resetting and the application time of the grayscale signal pulse is suppressed within the horizontal scanning time, the display state of and is maintained for the frame period, and the effect of white or black display on the entire pixel due to resetting is reduced. Hardly ever.

In practice, the relationship between the gradation signal voltage and the transmittance is not necessarily linear, but is non-linear as shown in FIG.
FIG. 4 is a plot of the inversion area ratio to a white state when a voltage V (charge CV) is applied to a pixel in a black state. The area ratio when applying a voltage of -V to a pixel in the white state and inverting it to black is obtained by inverting the curve in FIG. 4 because the white and black states are symmetric. In each case, the inversion is not linearly proportional to the applied voltage. Although the reason for this is not necessarily clear, it seems to be related to the fact that domain inversion hardly proceeds for a weak electric field. However, the relationship of the applied voltage V and the inverting area ratio T (V) is not linear, do it select the V ₁ and V ₂ as shown in FIG. _{4 T (V 1) + T} (V 2) = 100 relationships are satisfied. That is, for example, when it is desired to display a halftone level of 70%, the black reset white writing voltage is set to T ₁ = T ₁ in FIG.
Set voltages V ₁ to provide a 70%, set to a voltage V ₂ to provide a T ₂ = 30% of the voltage of the white reset black writing on the opposite side (where polarity negative). Thus, an arbitrary inversion characteristic T
It is clear that the method of the present invention can be applied to (V).

If the reset and the inversion cycle of the positive and negative polarities of the gradation signal are set as the horizontal scanning cycle, and the driving is performed so that the reset voltages of the adjacent scanning lines have the opposite polarities, the whole white and black areas at the time of resetting can be obtained. Black display is averaged, and flicker and the like become less noticeable.

When such a driving method is adopted, FIG.
As can be seen from the above, since the DC electric field applied to the FLC layer is averaged without being biased in one of the positive and negative directions, the above-described adhesion of impurity ions and the deterioration of the liquid crystal material are prevented, and a stable display is performed over a long period of time. Can be done.

In the above writing method, each pulse width in FIG. 2A is 5 μS, and the height of the reset pulse is 7
v (volts), Ta in FIG. 2B was set to 200 μS, Tf was set to 33 mS, and the height of the gradation signal pulse was selected from the characteristic curve of FIG. 4 as described above. Halftone levels up to 100% could be displayed stably.

Embodiment 2 FIG. 5 shows another embodiment of the present invention, which differs from FIG. 1 in that a two-terminal switching element is used. As the switching element, an MIM element, a diode, and a combination of a plurality of them can be considered. One terminal of the MIM is connected to the pixel electrode 51, the other terminal is connected to the scanning signal line 59, and the information signal electrode 58 is patterned in a stripe pattern on the counter substrate side. The MIM used in this embodiment has a structure in which a thin film of tantalum pentoxide is sandwiched between tantalums and has a threshold of about 1 v. FIGS. 6A and 6B show the timing of the drive signal according to the present embodiment. FIG. 6A shows a voltage applied to the information signal electrode 58, FIG. 6B shows a voltage applied to the scanning signal line 59, and FIG. 6C shows a voltage waveform appearing at both ends of the pixel. It is. At the time of reset, a negative voltage -7v is applied to the scanning line 59, and 0v is applied to the information electrode.
During writing, a positive selection voltage +7 V is applied to the scanning signal line.
Is applied to the information electrode from 0 V to +7 according to the gradation level.
v. In the opposite period, a pulse of the opposite polarity is applied, except that the grayscale signal level is not only of the opposite polarity but also has a different amplitude, and T (V ₁ ) + T (V ₂ ) = 100. % Is the same as in Example 1.

COMPARATIVE EXAMPLE 1 When driven by the one-polarity reset method shown in FIG.
The display disappeared in a few seconds. The pulse width and the frame period at this time were the same as in the first embodiment. The display disappears because ions move in the liquid crystal due to the residual DC voltage and create a built-in electric field on the side opposite to the writing electric field, thereby reducing the effective writing electric field.

COMPARATIVE EXAMPLE 2 The same drive waveforms as in FIG. 2 were used as in Example 1, except that the positive side reversal rate T (V ₁ ) was 70% and the negative side reversal rate T (V ₂ ) was 25.
%, The voltage was set for writing, but flicker was noticeable and the display quality was degraded. Further, the reversal rate T (V ₁ ) on the positive side is 70%, and the reversal rate T (V ₂ ) on the negative side is 35%.
Flicker was visible even when set to.

[0040]

As described above, by inverting the polarity of the reset voltage and the polarity of the gradation signal at regular intervals, the deterioration of the liquid crystal material and the FL caused by impurity ions are reduced.
It becomes possible to prevent a decrease in the bistability of C.

By setting the polarity inversion cycle to be a horizontal cycle and driving the reset voltages of adjacent scanning lines to have opposite polarities, flicker and the like can be prevented.

[Brief description of the drawings]

FIG. 1 is a block diagram of an FLC panel and a drive system according to a first embodiment of the present invention.

FIG. 2 is a diagram illustrating various signal waveforms in the driving method according to the first embodiment.

FIG. 3 is a display state diagram of a predetermined pixel (pixel of interest) in the first embodiment.

FIG. 4 is a diagram showing a relationship between a gradation signal and transmittance in a ferroelectric liquid crystal element.

FIG. 5 is a block diagram of an FLC panel and a drive system according to a second embodiment of the present invention.

FIG. 6 is a diagram illustrating various signal waveforms in the driving method according to the second embodiment.

FIG. 7 is a layer configuration diagram of an FLC element.

FIG. 8 is a characteristic diagram in the area gradation method by charge modulation.

FIG. 9 is a diagram schematically showing an example of a ferroelectric liquid crystal cell.

FIG. 10 is a diagram schematically illustrating an example of a ferroelectric liquid crystal cell in a case where ferroelectric liquid crystal molecules have a non-helical structure.

[Explanation of symbols]

 Reference Signs List 1 FLC panel 2 X driver 3 Y driver 4 Timing controller 5, 6 Polarity inversion circuit 7 Switching circuit 8 Signal line 9 Gate line 10 Signal line 12, 14 Voltage decay curve 51, 76a Pixel electrode 58, 76b Information signal electrode (counter electrode) 59) scanning signal line 70a, 70b substrate 71 gate electrode 72 insulating film 73 semiconductor film 74 source (drain) terminal 75 drain (source) terminal 77a insulating layer 77b insulating film 78 light shielding film 80 ferroelectric liquid crystal 81 sealing material 82a, 82b Polarizer 83 Reflector 91a, 91b Substrate 92 Liquid Crystal Molecular Layer

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-63-249897 (JP, A) JP-A-63-244021 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) G02F 1/133 G09G 3/18 G09G 3/36

Claims (6)

(57) [Claims] 1. A switching element provided for each pixel electrode arranged in a matrix, a ferroelectric liquid crystal device which sandwiches a ferroelectric liquid crystal between the counter electrode, ferroelectric whole pixels between the electrodes a reset voltage for resetting the first stable state of the liquid crystal, said reset voltage of opposite polarity is switched alternately and signal <br/> No. voltages Ru to transition to the second stable state pixels partially to chromatic voltage applying means for applying, and means for inverting the reset voltage every predetermined period, and means for inverting the signal voltage every constant period
A ferroelectric liquid crystal device, applies a positive polarity signal voltages V ₁ after applying the negative polarity reset voltage
A ferroelectric state inversion of the liquid crystal T when the (V _1)% and
And, a negative polarity signal voltage V ₂ after positive resetting voltage applied
The state reversal rate of the ferroelectric liquid crystal when applied is T (V ₂ )%
When a was, between them _{T (V 1) + T (} V 2) = the set of voltages _{V 1} and _{V 2} so as to satisfy 100% of the relationship
Consisting of Te ferroelectric liquid crystal devices. 2. The ferroelectric liquid crystal device according to claim 1, wherein said period is a scanning period of one screen. 3. A ferroelectric liquid crystal device of the reset voltage of the adjacent scanning lines have opposite polarities according to claim 1 or 2. 4. A ferroelectric liquid crystal instrumentation according to any one of claims 1-3, wherein said first stable state corresponds to the black state
Place . 5. The signal voltage according to claim 1, wherein said signal voltage includes gradation information.
The ferroelectric liquid according to any one of claims 1 to 4,
Crystal equipment. 6. The method according to claim 1, wherein said switching element is an MIM.
The ferroelectric liquid crystal device according to claim 1 .