EP0448032A2 - Verfahren zur Ansteuerung eines ferroelektrischen Flüssigkristallelementes und ferroelektrische Flüssigkristallanzeige - Google Patents

Verfahren zur Ansteuerung eines ferroelektrischen Flüssigkristallelementes und ferroelektrische Flüssigkristallanzeige Download PDF

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Publication number
EP0448032A2
EP0448032A2 EP91104222A EP91104222A EP0448032A2 EP 0448032 A2 EP0448032 A2 EP 0448032A2 EP 91104222 A EP91104222 A EP 91104222A EP 91104222 A EP91104222 A EP 91104222A EP 0448032 A2 EP0448032 A2 EP 0448032A2
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EP
European Patent Office
Prior art keywords
liquid crystal
voltage
ferroelectric liquid
tone signal
signal voltage
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Application number
EP91104222A
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English (en)
French (fr)
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EP0448032A3 (en
EP0448032B1 (de
Inventor
Yutaka C/O Canon Kabushiki Kaisha Inaba
Katsumi C/O Canon Kabushiki Kaisha Kurematsu
Shuzo C/O Canon Kabushiki Kaisha Kaneko
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Canon Inc
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Canon Inc
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Publication of EP0448032A3 publication Critical patent/EP0448032A3/en
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    • G—PHYSICS
    • G09—EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
    • G09G—ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
    • G09G3/00—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes
    • G09G3/20—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters
    • G09G3/34—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters by control of light from an independent source
    • G09G3/36—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters by control of light from an independent source using liquid crystals
    • G09G3/3611—Control of matrices with row and column drivers
    • G09G3/3648—Control of matrices with row and column drivers using an active matrix
    • G09G3/3651—Control of matrices with row and column drivers using an active matrix using multistable liquid crystals, e.g. ferroelectric liquid crystals
    • G—PHYSICS
    • G09—EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
    • G09G—ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
    • G09G3/00—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes
    • G09G3/20—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters
    • G09G3/34—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters by control of light from an independent source
    • G09G3/36—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters by control of light from an independent source using liquid crystals
    • G09G3/3611—Control of matrices with row and column drivers
    • G09G3/367—Control of matrices with row and column drivers with a nonlinear element in series with the liquid crystal cell, e.g. a diode, or M.I.M. element
    • G—PHYSICS
    • G09—EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
    • G09G—ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
    • G09G2310/00—Command of the display device
    • G09G2310/02—Addressing, scanning or driving the display screen or processing steps related thereto
    • G09G2310/0243—Details of the generation of driving signals
    • G09G2310/0251—Precharge or discharge of pixel before applying new pixel voltage
    • G—PHYSICS
    • G09—EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
    • G09G—ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
    • G09G2310/00—Command of the display device
    • G09G2310/06—Details of flat display driving waveforms
    • G09G2310/061—Details of flat display driving waveforms for resetting or blanking
    • G—PHYSICS
    • G09—EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
    • G09G—ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
    • G09G3/00—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes
    • G09G3/20—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters
    • G09G3/2007—Display of intermediate tones
    • G09G3/2011—Display of intermediate tones by amplitude modulation
    • G—PHYSICS
    • G09—EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
    • G09G—ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
    • G09G3/00—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes
    • G09G3/20—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters
    • G09G3/2007—Display of intermediate tones
    • G09G3/207—Display of intermediate tones by domain size control
    • G—PHYSICS
    • G09—EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
    • G09G—ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
    • G09G3/00—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes
    • G09G3/20—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters
    • G09G3/34—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters by control of light from an independent source
    • G09G3/36—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters by control of light from an independent source using liquid crystals
    • G09G3/3611—Control of matrices with row and column drivers
    • G09G3/3614—Control of polarity reversal in general

Definitions

  • the present invention relates to a method of driving a liquid crystal element mounted on a display device or the like and, more particularly, to a method of driving a ferroelectric liquid crystal element.
  • An electrooptical element using a ferroelectric liquid crystal (to be referred to as an FLC) has been applied to mainly a simple matrix display element because it responds to an electric field at a high speed and exhibits bistability.
  • an FLC element One characteristic feature of the active matrix FLC element is that a scanning time (frame period) of one frame can be determined regardless of the response speed of the FLC.
  • a frame period cannot be decreased to be less than (the response speed of the liquid crystal) x (the number of scanning lines). Therefore, as the number of scanning lines is increased, the frame period is undesirably prolonged.
  • the active matrix FLC In contrast to this, in the active matrix FLC, only charging/discharging of pixels on one scanning line need be performed within a selection time of the scanning line, and a switching element of the pixels is turned off to hold an application voltage to the liquid crystal after the selection time. Therefore, the liquid crystal responds within this holding time. For this reason, since the frame period is independent from the response speed of the liquid crystal, the active matrix FLC can operate at a speed of 33 ms that is used in normal television sets even if the number of scanning lines is increased.
  • the second characteristic feature of the active matrix FLC is easiness in tone display.
  • One tone display method of the active matrix FLC is described in EP 284,134, and the principle of the method is that pixels are reset in one stable state beforehand and a charge amount Q is applied to a pixel electrode through an active element, thereby partially causing switching to the second stable state in one pixel.
  • an area in which the switching to the second stable state is caused is a and the magnitude of spontaneous polarization of the FLC is P s
  • an electric charge of 2P s ⁇ a is moved upon switching, and the switching to the second stable state continues until this electric charge cancels the electric charge Q applied first.
  • an area of is set in the second stable state.
  • the control of a i.e., an area tone is realized by changing Q.
  • Figs. 4A and 4B plot changes over time in inter-pixel electrode voltage (Fig. 4A) and transmitted light intensity (Fig. 4B) obtained when the reset and the tone display are repeated at a period of 33 ms as in a normal television set.
  • the voltage is abruptly attenuated immediately after the active element is turned off, but then the attenuation becomes very moderate.
  • the transmitted light intensity is abruptly changed immediately after the active element is turned off, the change gradually becomes moderate. That is, although an electric field is present between the electrodes, the reversal between the two states progresses only very slowly or stops.
  • a residual DC electric field is continuously applied on the liquid crystal to lead to degradation in the liquid crystal material.
  • impurity ions in the liquid crystal are adhered on the interface of the insulating layer by a DC electric field to generate an electric field in a direction opposite to the DC electric field, thereby degrading the bistability of the FLC.
  • Fig. 5 is a sectional view showing a practical example of a ferroelectric liquid crystal cell using a TFT to be used in the present invention.
  • a semiconductor film 26 (e.g., amorphous silicon doped with hydrogen atoms) is formed on a substrate 30a (e.g, glass or plastic material) via a gate electrode 34 and an insulating film 32 (e.g., a silicon nitride film doped with hydrogen atoms), and a TFT constituted by two terminals 18 and 21 in contact with the semiconductor film 26 and a pixel electrode 22 (e.g., ITO: Indium Tin Oxide) connected to the terminal 21 of the TFT are also formed on the substrate 30a.
  • a substrate 30a e.g, glass or plastic material
  • a gate electrode 34 and an insulating film 32 e.g., a silicon nitride film doped with hydrogen atoms
  • a TFT constituted by two terminals 18 and 21 in contact with the semiconductor film 26 and a pixel electrode 22 (e.g., ITO: Indium Tin Oxide) connected to the terminal 21 of the TFT are also formed on the substrate 30a.
  • an insulating layer 23b e.g., polyimide, polyamide, polyvinylalcohol, polyparaxylylene, SiO, or SiO2
  • a light-shielding film 19 consisting of aluminum or chromium
  • a counter electrode 31 ITO: Indium Tin Oxide
  • an insulating film 32 are formed on a substrate 30b as a counter substrate.
  • a ferroelectric liquid crystal 33 is sandwiched between the substrates 30a and 30b.
  • a sealing member 35 for sealing the ferroelectric liquid crystal 33 is formed around the substrates 30a and 30b.
  • Polarizers 29a and 29b in a state of crossed Nicols are arranged at two sides of the liquid crystal element having the above cell structure, and a reflecting plate 28 (a diffusion-reflecting aluminum sheet or plate) is located behind the polarizer 29b so that an observer A can observe a display state by reflected light I1 of incident light I0.
  • a reflecting plate 28 a diffusion-reflecting aluminum sheet or plate
  • source and drain electrodes respectively corresponding to the terminals 18 and 21 of the TFT are named assuming that a current flows from the drain to the source.
  • the source can serve as the drain.
  • the pole of the reset voltage and that of the tone signal voltage are reversed every predetermined period, a phenomenon in that a DC electric field is continuously applied on a liquid crystal can be prevented.
  • An example of a ferroelectric liquid crystal used in a method of driving a ferroelectric liquid crystal element according the present invention is a substance which takes one of first and second optically stable states in accordance with an applied electric field, i.e., has a bistable state with respect to an electric field, in particular, a liquid crystal having such properties.
  • a most preferable example of the ferroelectric liquid crystal having the bistability and usable in the driving method of the present invention is a ferroelectric chiral smectic liquid crystal such as a liquid crystal having a chiral smectic C phase (SmC * ), H phase (SmH*), I phase (SmI * ), J phase (SmJ * ), K phase (SmK * ), G phase (SmG * ), or F phase (SmF * ).
  • ferroelectric liquid crystal is described in, e.g., "Ferroelectric Liquid Crystals", LE JOURNAL DE PHYSIQUE LETTERS, 36 (L-69), 1975; “Submicro Second Bistable Electrooptic Switching in Liquid Crystals”, Applied Physics Letters, 36 (11), 1980; or “Liquid Crystals”, Solid-State Physics, 16 (141), 1981.
  • the ferroelectric liquid crystals described in these references can be used.
  • ferroelectric liquid crystal compound usable in the method of the present invention are decyloxybenzylidene-p'-amino-2-methylbutylcinnamate (DOBAMBC), hexyloxybenzylidene-p'-amino-2-chloropropylcinnamate (HOBACPC), and 4-o-(2-methyl)-butylresorcylidene-4'-octylaniline (MBRA8).
  • DOBAMBC decyloxybenzylidene-p'-amino-2-methylbutylcinnamate
  • HOBACPC hexyloxybenzylidene-p'-amino-2-chloropropylcinnamate
  • MBRA8 4-o-(2-methyl)-butylresorcylidene-4'-octylaniline
  • the element When an element is to be formed by using these materials, to hold a temperature state which allows the liquid crystal compound to have the SmC * or SmH * phase, the element can be supported by a copper block or the like in which a heater is buried.
  • Fig. 9 is a view showing an arrangement of a ferroelectric liquid crystal cell as a model.
  • substrates (glass plates) 91a and 91b is coated with a transparent electrode consisting of In2O3, SnO2, or ITO (Indium-Tin Oxide), and an SmC * -phase liquid crystal in which a liquid crystal molecular layer 92 is oriented perpendicularly to the glass surface is sealed between the substrates.
  • Each liquid crystal molecule 93 indicated by a thick line has a dipole moment (P ⁇ ) 94 perpendicular to the molecule.
  • P ⁇ dipole moment
  • the orientation directions of the liquid crystal molecules 93 can be changed such that all of the dipole moments (P ⁇ ) 94 are directed in the direction of the electric field.
  • the liquid crystal molecule 93 has an elongated shape and exhibits refractive index anisotropy between its major and minor axis directions. Therefore, if polarizers having a positional relationship of crossed Nicols are arranged above and below the glass surface, a liquid crystal optical modulating element which changes its optical characteristics in accordance with a voltage application pole is obtained.
  • the spiral structure of the liquid crystal molecule is untied (non-spiral structure) even when no electric field is applied, and a dipole moment Pa or Pb of the molecule is directed upward (104a) or downward (104b), as shown in Fig. 10.
  • a dipole moment Pa or Pb of the molecule is directed upward (104a) or downward (104b), as shown in Fig. 10.
  • the dipole moment changes its direction to the upward direction 104a or the downward direction 104b in correspondence with the electric field vector of the electric field Ea or Eb, and the liquid crystal molecules are oriented in either a first or second stable state 105a or 105b accordingly.
  • a response speed is very high
  • second the orientation of a liquid crystal molecule has a bistable state.
  • the second advantage will be described below by taking the structure shown in Fig. 10 as an example.
  • the electric field Ea is applied
  • the liquid crystal molecules are oriented in the first stable state 105a, and this state is stable even after the electric field is turned off.
  • the electric field Eb in the opposite direction is applied
  • the liquid crystal molecules are oriented in the second stable state 105b, i.e., change their directions and remain in this state even after the electric field is turned off.
  • the liquid crystal molecules are kept in either orientation state unless the applied electric field Ea or Eb exceeds the threshold value.
  • the thickness of the cell is preferably as small as possible.
  • the thickness is preferably 0.5 to 20 ⁇ m, and most preferably, 1 to 5 ⁇ m.
  • a liquid crystal-electrooptical device having a matrix electrode structure using a ferroelectric liquid crystal of this type is proposed in, e.g., U.S.P. No. 4,367,924 to Clark and Ragaval.
  • the present invention is based on the fact that in an element which has an FET (Field-Effect transistor) such as a TFT (Thin Film Transistor) and constitutes an active matrix, the functions of the drain and source can be switched by reversing an application voltage to the drain and source.
  • An element constituting the active matrix may be either an amorphous silicon TFT or a polycrystalline silicon TFT as long as the element has the FET structure.
  • a bipolar transistor having a structure except for the FET structure can be similarly used.
  • a two-terminal switching element such as an MIM element or a diode can be used.
  • V D drain voltage
  • V G gate voltage
  • V S source voltage
  • V P gate-to-source threshold voltage
  • a p-type FET is rendered conductive when V G ⁇ V S + V P and non-conductive when V G > V S + V P for V D ⁇ V S .
  • a terminal serving as a drain and that serving as a source are determined by the application direction of a voltage. That is, a terminal at a lower voltage serves as a source in an n-type FET whereas that at a higher voltage serves as a source in a p-type FET.
  • ferroelectric liquid crystal of positive and negative voltages to be applied to a liquid crystal cell, one to be set as a "bright” state and the other to be set as a “dark” state are freely set in accordance with the directions of polarization axes of a pair of polarizers arranged above and below the cell with a relationship of crossed Nicols therebetween and the direction of the major axis or a liquid crystal molecule.
  • an electric field to be applied to the liquid crystal cell is controlled by controlling an interterminal voltage of each element of the active matrix, thereby obtaining a display. Therefore, a voltage level of each signal need not be limited to those of the following embodiments, but the present invention can be carried out by maintaining relative potential differences between the signals.
  • Fig. 1 shows an arrangement of an FLC panel and a driving system for driving the panel according to an embodiment of the present invention.
  • this embodiment comprises an active matrix-driven type FLC panel 1 having a TFT as an active element, an X driver 2 constituted by, e.g., a shift register and a holding circuit, a Y driver 3 constituted by, e.g., a shift register and a latch, a timing controller 4, a pole reverse circuit 5 for a video signal, a pole reverse circuit 6 for a reset signal, and a switching circuit 7 for the video and reset signals.
  • an X driver 2 constituted by, e.g., a shift register and a holding circuit
  • a Y driver 3 constituted by, e.g., a shift register and a latch
  • a timing controller 4 a pole reverse circuit 5 for a video signal
  • a pole reverse circuit 6 for a reset signal
  • switching circuit 7 for the video and reset signals.
  • a first gate pulse 1 and a second gate pulse 2 delayed slightly from the first gate pulse 1 by a time (Td) as shown in Fig. 2B are generated by the timing controller and the Y driver and supplied to each gate line 9 at a sequential horizontal period.
  • Td time
  • a frame period Tf is present before the next gate pulse
  • pulses 3 and 4 shown in Fig. 2B correspond to this gate pulse.
  • Operation timings of the pole reverse circuits 5 and 6 and the switching circuit 7 are controlled in synchronism with the timings of the gate pulses 1, 2, 3, 4, ... such that an output to an input signal line 10 of the X driver becomes a negative reset voltage, a positive tone signal voltage, a positive reset voltage, a negative tone signal voltage, ...
  • a drive signal as shown in Fig. 2A is applied to a pixel of interest via the TFT.
  • the TFT is in an OFF state when no signal is applied thereto and the spontaneous polarization P S of the FLC has the charge canceling effect as described above, an interelectrode voltage waveform as shown in Fig. 2C is obtained in the pixel of interest as a capacitive load.
  • a timing 1 corresponds to the negative reset, and all the FLCs in the pixel return to the first stable state at this timing.
  • a total black state as shown in Fig. 3A is obtained within the time Td.
  • Fig. 6 plots a reversed area ratio to the white state obtained when the voltage V (charge CV) is applied to a pixel in the black state.
  • An area ratio obtained when the voltage -V is applied to a pixel in the white state to reverse the pixel into the black state is given by reversing the curve shown in Fig. 6 because the white state and the black state are symmetrical. In either case, the reversal is not linearly proportional to the application voltage.
  • the total white and total black displays upon resetting are averaged to make flickering or the like more inconspicuous.
  • the DC electric field applied on the FLC layer is not shifted to positive or negative but averaged, as shown in Fig. 2C. Therefore, adhesion of impurity ions and degradation in a liquid crystal material can be prevented to realize a stable display throughout a long operation period.
  • each pulse width and the level of the reset pulses 1 and 3 shown in Fig. 2A were set at 5 ⁇ s and 7 V, respectively, T ⁇ and Tf shown in Fig. 2B were set at 200 ⁇ s and 33 ms, respectively, and the level of the tone signal pulse was selected in accordance with the characteristic curve shown in Fig. 6.
  • a halftone level substantially from 0% to 100% was able to be stably displayed.
  • Fig. 7 shows another embodiment of the present invention using a two-terminal switching element unlike in the embodiment shown in Fig. 1.
  • an MIM element, a diode, and a combination of a plurality of MIM elements and diodes may be used as the switching element, this embodiment will be described below by taking an MIM as an example.
  • One terminal of the MIM is connected to a pixel electrode, its other terminal is connected to a scanning signal line, and a stripe-like information signal electrode 81 is patterned on a counter substrate.
  • the MIM used in this embodiment has a structure in which a thin film consisting of tantalum pentoxide is sandwiched by tantalum and has a threshold value of about 1 V.
  • Fig. 8A, 8B, and 8C show timings of drive signals used in this embodiment, in which Fig. 8A shows a voltage to be applied to the information signal electrode, Fig. 8B shows a voltage to be applied to the scanning signal line, and Fig. 8C shows a voltage waveform appearing across the two ends of a pixel.
  • a negative voltage of -7 V is applied to the scanning line and 0 V is applied to the information electrode upon resetting indicated by 1.
  • a positive selection voltage of +7 V is applied to the scanning line and a voltage of 0 V to +7 V is applied to the information electrode in accordance with a tone level upon writing indicated by 2.
  • pulses having poles opposite to those applied in the periods 1 and 2 are applied. Note that as in Embodiment 1, the tone signal level not only has the pole opposite to that applied in the period 2 but also generally has a different amplitude, i.e., is so selected as to satisfy .
  • 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.
  • a state reverse ratio of the ferroelectric liquid crystal is T(V)% when the tone signal voltage is V

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  • Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Crystallography & Structural Chemistry (AREA)
  • Physics & Mathematics (AREA)
  • Computer Hardware Design (AREA)
  • General Physics & Mathematics (AREA)
  • Theoretical Computer Science (AREA)
  • Liquid Crystal (AREA)
  • Liquid Crystal Display Device Control (AREA)
EP91104222A 1990-03-20 1991-03-19 Verfahren zur Ansteuerung eines ferroelektrischen Flüssigkristallelementes und ferroelektrische Flüssigkristallanzeige Expired - Lifetime EP0448032B1 (de)

Applications Claiming Priority (4)

Application Number Priority Date Filing Date Title
JP7051190 1990-03-20
JP70511/90 1990-03-20
JP74205/91 1991-03-15
JP3074205A JP2805253B2 (ja) 1990-03-20 1991-03-15 強誘電性液晶装置

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EP0448032A2 true EP0448032A2 (de) 1991-09-25
EP0448032A3 EP0448032A3 (en) 1992-11-19
EP0448032B1 EP0448032B1 (de) 1996-07-03

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AT (1) ATE140097T1 (de)
DE (1) DE69120564T2 (de)

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0528685A2 (de) * 1991-08-20 1993-02-24 Sharp Kabushiki Kaisha Ferroelektrische Flüssigkristall-Anzeigevorrichtung
EP0536744A2 (de) * 1991-10-09 1993-04-14 Matsushita Electric Industrial Co., Ltd. Verfahren zum Steuern einer Anzeige
EP0552045A1 (de) * 1992-01-17 1993-07-21 Sharp Kabushiki Kaisha Verfahren zum Steuern eines antiferroelektrischen Flüssigkristallgeräts
US5270844A (en) * 1991-12-06 1993-12-14 Canon Kabushiki Kaisha Liquid crystal optical element with minute insulation portions on the electrodes
WO1996006422A1 (en) * 1994-08-23 1996-02-29 Philips Electronics N.V. Display device

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Publication number Priority date Publication date Assignee Title
JPH07120722A (ja) * 1993-06-30 1995-05-12 Sharp Corp 液晶表示素子およびその駆動方法
JP3534086B2 (ja) * 2001-04-27 2004-06-07 松下電器産業株式会社 液晶表示装置の駆動方法
US6989812B2 (en) 2001-02-05 2006-01-24 Matsushita Electric Industrial Co., Ltd. Liquid crystal display unit and driving method therefor
US8564514B2 (en) 2001-04-18 2013-10-22 Fujitsu Limited Driving method of liquid crystal display device and liquid crystal display device
TWI404011B (zh) 2009-03-18 2013-08-01 Pervasive Display Co Ltd 非揮發性顯示模組及非揮發性顯示裝置

Citations (3)

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Publication number Priority date Publication date Assignee Title
EP0197742A2 (de) * 1985-04-03 1986-10-15 Nortel Networks Corporation Flüssigkristall-Zellenadressierung
EP0284134A1 (de) * 1987-03-17 1988-09-28 Koninklijke Philips Electronics N.V. Verfahren zur Flüssigkristall-Anzeigeeinrichtungssteuerung und ergänzende Aufzeichnungsvorrichtung
EP0362939A1 (de) * 1988-10-05 1990-04-11 Koninklijke Philips Electronics N.V. Verfahren zur Steuerung einer Anzeigevorrichtung

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EP0528685A2 (de) * 1991-08-20 1993-02-24 Sharp Kabushiki Kaisha Ferroelektrische Flüssigkristall-Anzeigevorrichtung
EP0528685A3 (de) * 1991-08-20 1994-12-21 Sharp Kk
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EP0552045A1 (de) * 1992-01-17 1993-07-21 Sharp Kabushiki Kaisha Verfahren zum Steuern eines antiferroelektrischen Flüssigkristallgeräts
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DE69120564D1 (de) 1996-08-08
DE69120564T2 (de) 1996-12-19
ATE140097T1 (de) 1996-07-15
JPH04218023A (ja) 1992-08-07
JP2805253B2 (ja) 1998-09-30
EP0448032A3 (en) 1992-11-19
EP0448032B1 (de) 1996-07-03

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