EP0600096B1 - Dispositif d'affichage actif matriciel a cristaux liquides a deux terminaux et systeme de commande de ce dispositif - Google Patents

Dispositif d'affichage actif matriciel a cristaux liquides a deux terminaux et systeme de commande de ce dispositif Download PDF

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Publication number
EP0600096B1
EP0600096B1 EP93913550A EP93913550A EP0600096B1 EP 0600096 B1 EP0600096 B1 EP 0600096B1 EP 93913550 A EP93913550 A EP 93913550A EP 93913550 A EP93913550 A EP 93913550A EP 0600096 B1 EP0600096 B1 EP 0600096B1
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Prior art keywords
periods
select
terminal type
voltage
period
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German (de)
English (en)
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EP0600096A4 (en
EP0600096A1 (fr
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Seigo Togashi
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Citizen Watch Co Ltd
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Citizen Watch Co Ltd
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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
    • G09G3/367—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
    • G09G2310/06—Details of flat display driving waveforms
    • 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
    • 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
    • G09G3/2014—Display of intermediate tones by modulation of the duration of a single pulse during which the logic level remains constant

Definitions

  • Liquid-crystal display devices have been widely used as flat-panel displays because they consume small amounts of electric power.
  • an active matrix system in which a switching element is incorporated in each of the pixels is now being used in TVs and data terminals as a display element with large capacity and high quality.
  • switching elements there are used a three-terminal type elements such as TFTs (thin-film transistor) and two-terminal type elements having non-linear resistive characteristics such as diodes or MIMs (metal-insulation-method structure).
  • the two-terminal type elements are simpler in structure than the three-terminal type elements, and their use is expected to grow in the future.
  • the present invention is concerned with an active matrix liquid-crystal display device which uses switching elements of the two-terminal type and a method of driving the same.
  • Fig. 3 is a block diagram of an active matrix liquid-crystal display device which employs two-terminal type switching elements.
  • data lines D1, D2, ---, DM and scanning lines S1, S2, ---, SN in the form of a matrix.
  • a liquid-crystal pixel 1 and a two-terminal type switching element 2 are provided corresponding to each of their intersecting points.
  • the data lines are served with data signals from a data line driver circuit 4, and the scanning lines are served with scanning signals from a scanning line driver circuit 5.
  • To the data line driver circuit 4 and the scanning line driver circuit 5 are connected a control circuit and a power source circuit 6 for processing clock signals and image signals 7.
  • the element having a metal-insulator-metal (conductor) structure and non-linear current-voltage characteristics is, in many cases, used as a two-terminal type switching element.
  • a representative MIM has a structure in which the lower electrode is composed of Ta, the insulator is composed of an anodically oxidized film (TaOx) of Ta, and the upper electrode is composed of ITO (transparent conductor), and is produced using two patterns (masks).
  • Fig. 2 illustrates waveforms of scanning signals and a data signal waveform in a conventional method of driving a two-terminal type active matrix liquid-crystal display device such as diode, MIM or the like (Japanese Unexamined Patent Publication (Kokai) No. 59-57288), wherein ⁇ (n) and ⁇ (n + 1) denote scanning signals applied to the n-th and (n + 1)th scanning lines.
  • the scanning signal has a select period for writing an electric charge that is to be stored in a liquid-crystal display pixel and a holding period for holding the electric charge.
  • the liquid-crystal display pixel must be driven with voltages of two polarities.
  • the select periods include first select periods H(n) and H'(n + 1) in which a voltage of positive polarity having a select potential Va1 is applied to said liquid-crystal display pixels and to said two-terminal type switching elements to write a positive electric charge onto the liquid-crystal display pixels, and second select periods H'(n) and H(n + 1) in which a voltage of negative polarity having a select potential Va2 is applied to write a negative electric charge onto the liquid-crystal display pixels.
  • 0ther non-select periods are the holding periods in which the potentials Vb1 and Vb2 are held.
  • a data signal D(m) applied to the m-th data line assumes a potential between the data potentials Vd1 and Vd2.
  • Either amplitude modulation or pulse width modulation is used for the gradation display.
  • Fig. 2 illustrates the latter example wherein reference numeral 12 denotes a reference potential which in principle remains equivalent even when it undergoes a change in the whole system that is expressed by a predetermined potential in this drawing. In many cases, therefore, the reference potential 12 changes depending upon a relationship relative to the power source voltage of the driver circuit.
  • the potentials Va1, Va2, Vb1 and Vb2 are symmetrically illustrated with respect to the reference potential.
  • the polarity of the select potential is inverted for the n-th and (n+1)th consecutive select periods H(n), H(n+1), H'(n) and H'(n+1), i.e., the polarity is inverted for every row. In many cases, however, the polarity may be inverted for every field.
  • Figs. 4(A) to 4(D) The greatest problem of the active matrix liquid-crystal display device employing two-terminal type switching elements, and particularly MIMs, as switching elements may be the sticking of image and the phenomenon of residual image.
  • Fig. 4(A) illustrates an ideal change in the light transmission factor in the case of normally white in which the gradation successively changes like white, half tone, black and half tone
  • Fig. 4(B) illustrates a practical change in the light transmission factor in the same display.
  • the waveform of a change of the transmission factor of Fig. 4(B) is not in agreement with that of Fig. 4(A).
  • the amount of current flowing through the switching element varies depending upon the voltage that is applied during the select period, and the voltage that is applied varies depending upon the degree of gradation that is displayed.
  • the current increases toward the darker side and when the gradation is changed as shown in Fig. 4(A), the amount of current flowing through the switching element changes as shown in Fig. 4(C). Therefore, a change in the threshold voltage becomes as shown in Fig. 4(D); i.e., residual image and sticking of image take place for a predetermined period of time from when the gradation is changed until the gradation is stabilized.
  • the threshold voltage Vth changes either in white condition or in black condition. In principle, therefore, the sticking of image takes place either in white condition or in black condition. Under the white or black condition, however, the transmission factor changes little depending upon the applied voltage, and the printing of image the most remarkably takes place under the half tone.
  • EP 0 321 962 A2 discloses a driving method for an active matrix liquid-crystal display device by using scanning signals the field period of which consists of a selection period and a non-selection period, respectively. Use is made of two common potential levels which are changed every field or every selection period or every plurality of selection periods so that the active matrix display has pixels with different polarities of the voltage applied to the liquid crystal of the respective pixels. If the common potential levels are changed every field, this is done within the non-selection periods. The change of the two common potential levels is done to reduce the maximum voltage necessary. No current is applied to the pixels by this change of the common potentials.
  • EP 0 508 628 A2 which document represents state-of-the-art according to Art. 54(3) EPC, discloses a driving method for an active matrix liquid-crystal display device by using scanning signals which include select periods, current-application periods preceding the select periods, and holding periods succeeding the select periods.
  • the maximum voltage values used in the current-application periods are equal to or greater than the voltage levels of the select periods.
  • the current-application part of the scanning signal preceding a respective select period involve one or more current-application periods directly following on one another and having alternate potential polarities.
  • the object of the present invention is to provide a driving method which is capable of improving the sticking of image and the phenomenon of residual image by passing a current through the switching element in an amount greater than that of the prior art, and a liquid crystal display device driven in this manner.
  • a method of driving the active matrix liquid-crystal display device having the features of claim 1 which makes use, as a scanning signal, of a signal which has select periods, special current-application periods which precede the select periods and holding periods that succeed the select periods.
  • the basic technical constitution therefor is concerned with a two-terminal type active maxtrix liquid-crystal display device according to claim 9 which has a plurality of data lines and scanning lines, and liquid-crystal pixels provided for the intersecting points of said data lines and said scanning lines, said liquid-crystal pixels having at least one two-terminal type switching element and being driven by a scanning signal applied to the scanning lines and by a data signal applied to the data lines, wherein said scanning signal has select periods for writing an electric charge that is to be stored in said liquid-crystal pixels, the special current-applicaton periods for applying a current to said switching elements preceding said select periods, and holding periods succeeding said select periods.
  • the invention further includes a device as claimed in claim 9.
  • Fig. 8 is a block diagram illustrating the constitution of an active matrix liquid-crystal display device according to the present invention.
  • the basic constitution is substantially the same as that of a conventional liquid-crystal display device shown in Fig. 3, and the portions having the same functions are denoted by the same reference numerals but are not described in detail here.
  • the active matrix liquid-crystal display device is different from the conventional active matrix liquid-crystal display device of Fig. 3 with respect to a control circuit 6.
  • the control circuit 6 is provided with a current application period setting means 61 which sets current application periods for applying a current to the two-terminal type switching elements 2 preceding the select periods, a polarity setting means 62 which determines the polarity of the current applied to the two-terminal type switching elements 2 during said current application periods, a voltage setting means 63 that determines a voltage applied to the two-terminal type switching elements 2, and an application number setting means 64 which determines a number of times of applying the current to the two-terminal type switching elements 2. These means are controlled by a suitable control means.
  • Fig. 8 illustrates the constitution of the liquid-crystal display device according to the present invention, i.e., illustrates a two-terminal type active matrix liquid-crystal display device which has a plurality of data lines and scanning lines, liquid-crystal pixels provided for the intersecting points of said data lines and said scanning lines, said liquid-crystal pixels having at least one two-terminal type switching element, and further has a control means that includes a control circuit for controlling said scanning lines, said data lines, said liquid-crystal pixels, and said two-terminal type switching elements, said liquid-crystal display pixels being driven by a scanning signal applied to the scanning lines and by a data signal applied to the data lines in response to a control signal from said control means, wherein said control means comprises a current application period setting means which sets current application periods for applying a current to said two-terminal type switching elements 2 preceding predetermined select periods in which at least said scanning signal writes an electric charge that is to be stored in said liquid-crystal display elements, a current application period
  • Fig. 8 further illustrates a method of driving a two-terminal type active matrix liquid-crystal display device which has a plurality of data lines and scanning lines, and liquid-crystal pixels provided for the intersecting points of said data lines and said scanning lines, said liquid-crystal pixels having at least one two-terminal type switching element and being driven by a scanning signal applied to the scanning lines and by a data signal applied to the data lines, wherein said scanning signal has select periods for writing an electric charge that is to be stored in said liquid-crystal pixels, current application periods for applying a current to said two-terminal type switching elements preceding said select periods, and holding periods for holding the electric charge of said liquid-crystal display pixels succeeding said select periods.
  • the scanning signal has first select periods for applying a voltage of a first polarity to the liquid-crystal display pixels and to said two-terminal type switching elements and second select periods for applying a voltage of a second polarity thereto, and wherein a voltage of a polarity opposite to that of the voltages of said select periods is applied to said two-terminal type switching elements in-the current application periods which precede said select periods.
  • the scanning signal has first select periods for applying a voltage of a first polarity to the two-terminal type switching elements and second select periods for applying a voltage of a second polarity thereto, and wherein the current application periods which precede said select periods have a potential equal to the potential of said select periods in order to effect the writing of a polarity opposite to that of said select periods.
  • the scanning signal has first select periods for applying a voltage of a first polarity to said two-terminal type switching elements and second select periods for applying a voltage of a second polarity thereto, and wherein in the current application periods which precede said select periods, a voltage of a polarity opposite to that of the voltages of said select periods and a voltage of a polarity same as that of said select periods are applied to said two-terminal type switching elements.
  • the scanning signal has first select periods for applying a voltage of a first polarity to said two-terminal type switching elements and second select periods for applying a voltage of a second polarity thereto, and wherein the current application periods which precede said select periods have a potential equal to the potential of the select periods to effect the writing of a polarity opposite to that of said select periods or has a potential of a polarity which is the same as that of said select periods and is equal to the potential of said select periods.
  • the scanning signal has first select periods for applying a voltage of a first polarity to said two-terminal type switching elements and second select periods for applying a voltage of a second polarity thereto, and wherein in the current application periods which precede said select periods, the potential may have an absolute value that is greater than the absolute value of the potential of said select periods, and the length of the current application periods of said scanning signal may be equal to the length of said selection periods.
  • the length of the current application periods of said scanning signal may be longer than the length of the select periods, or the current application periods of said scanning signal may utilize the select periods of a scanning signal that is applied to other scanning lines.
  • the select periods of said scanning signal may be continuous to the current application periods that precede said select periods, and a period may be inserted between the current application periods of said scanning signal and the select periods, said period having a potential which applies no current to the two-terminal type switching elements.
  • said reference potential may undergo a change during the select periods and during the current application periods that precede said select periods.
  • Figs. 1(A) to 1(D) illustrate a driving method according to an embodiment of the present invention, wherein ⁇ (n) and ⁇ (n+1) denote scanning signals applied to the n-th and (n+1)th scanning lines.
  • This embodiment deals with a so-called every-row inversion as will be obvious from the select polarities of the periods shown in Fig. 1(C)24.
  • the present invention is in no way limited to the every-row inversion only but can be effectively adapted to the frame inversion or to the intra-row inversion, as a matter of course.
  • the scanning signal ⁇ (n) has a select period H(n) of positive polarity and a select period H'(n) of negative polarity
  • the scanning signal ⁇ (n+1) has a select period H'(n+1) of positive polarity and a select period H(n+1) of negative polarity.
  • These signals have a select potential Va1 when they are of positive polarity and a select potential Va2 when they are of negative polarity.
  • the periods that follow the select periods are holding periods.
  • a potential Vb1 is held in a holding period that succeeds the select period of positive polarity
  • a potential Vb2 is held in a holding period that succeeds the select period of negative polarity.
  • periods 26 and 31 assume select potentials Va1 and Va2 in the select periods H(n) and H'(n), and the potentials Vb1 and Vb2 are held in other periods. It is, however, also allowable to assume the select potentials through the whole period.
  • the feature resides in the periods that precede the select periods.
  • the scanning signal ⁇ (n) there exist periods in which no holding potential is assumed in the periods H(n-1) and H(n-2) that precede the select period H(n) of positive polarity. These periods which are called current application periods correspond to 27 and 28 in Fig. 1.
  • a voltage written onto and stored in the liquid-crystal pixels is determined by a select potential period 26 of the select period H(n), and a period which is just preceding does not seriously affect the image.
  • the feature resides in that a current is applied while impressing a large voltage upon the two-terminal type switching elements by utilizing the above period which least affects the image.
  • a period H(n-1) just preceding the select period H(n) of positive polarity is provided with a period 27 for applying a large potential of different polarity or, in this case, for applying the select potential Va2 of negative polarity
  • a preceding period H(n-2) thereof is provided with a period 28 for applying a large potential of a polarity different from that of the period 27 or, in this case, for applying the select potential Va1 of positive polarity.
  • the period H'(n-1) which just precedes is provided with a period 32 for applying a large potential of a different polarity or, in this case, for applying the select potential Va1 of positive polarity and a preceding period H'(n-2) thereof is provided with a period 33 for applying a large potential of a polarity different from that of the period 32 or, in this case, for applying the select potential Va2 of negative polarity.
  • provision of the periods 29, 30, 20 and 21 is advantageous.
  • the signal of the present invention can be generated by simply changing the timing but without changing the circuit.
  • a data signal D(m) applied to an m-th data line assumes a potential between the data potentials Vd1 and Vd2 like 25 in the same manner as the prior art of Fig. 2.
  • Either amplitude modulation or pulse-width modulation is employed for the gradation display.
  • Figs. 1(A) to 1(D) illustrate the latter case.
  • Reference numeral 22 denotes a reference potential which in this diagram is expressed as a predetermined potential but may vary in the whole system.
  • Fig. 1 shows the potentials Va1, Va2, Vb1 and Vb2 which are symmetrical relative to the reference potential, they may often be asymmetrical relative to the reference potential.
  • this embodiment corresponds to the case of every-row inversion, the invention may further be adapted to the field inversion or to the intra-row inversion.
  • Figs. 6(A) to 6(D) illustrate a scanning signal ⁇ (n) according to another embodiment of the present invention.
  • the timings correspond to those of the scanning signal ⁇ (n) used in the embodiment of Figs. 1(A) to 1(D), and the select periods H(n), H'(n) and the succeeding holding periods are the same, but the current application periods only are different.
  • the potential Va2 of the current application period 36 of ⁇ (n) has a polarity and a value which are the same as those of the select potential of a scanning signal on a scanning line that is selected at the same time.
  • the potential Va1 of the current application period 37 has a polarity and a value same as the select potential of scanning signals ⁇ (n-1) and ⁇ (n-3) on the scanning lines that are selected at the same time.
  • the potential Va2 of the current application period 38 of ⁇ (n) has a polarity opposite to that of the select potential of a scanning signal on a scanning line that is selected at the same time.
  • the potential Va1 of the current application period 39 has a polarity opposite to that of the select potential of a scanning signal ⁇ (n-2) on a scanning line that is selected at the same time.
  • the spatial frequency of an image is relatively low, and the gradation of image in many cases resembles the neighboring n-th row and (n-2)th row. For instance, it is presumed that both the n-th row and (n-2)th row have a black (maximum voltage) gradation in the normally white mode.
  • a maximum current flows in the select period H(n) of ⁇ (n) but a minimum current flows in the current application period since the voltage of ⁇ (n) has an opposite polarity.
  • the potential during the current application periods is the same as the select potential Va1, Va2 giving great advantage from the standpoint of decreasing the number of power sources for the circuits. In the present invention, however, the potential need not necessarily be the same as the select potential.
  • the potential in the current application periods is Vcl during the periods 43 and 44, and is Vc2 during the periods 42 and 45, which are greater than the select potential.
  • Figs. 7(A) and 7(B) illustrate an example which in principle is quite equivalent to that of Fig. 1, and in which the reference potential 22 of Figs. 1(A) to 1(D) is varied for every row as designated at 50 to decrease the amplitude of the scanning signal.
  • the amplitude of the data signal is increased, on the other hand.
  • the driving waveforms are equivalent though they appear to be different.
  • the present invention encompasses even such a fluctuated potential provided it is equivalent as described with the reference potential fixed.
  • the above embodiment has dealt with the cases of current application periods of one row and two rows.
  • the invention can be adapted even to the cases of three or more rows. The same holds even for the continuous or discrete cases. Similarly, the holding period need not be continuous after the select periods.
  • the greatest problem inherent in the conventional method of driving the active matrix liquid-crystal display device using two-terminal type switching elements is the sticking of image and the phenomenon of residual image caused by the threshold voltage Vth of the switching element that changes depending upon the amount of current that flows.
  • the sticking and residual image are decreased by providing current application periods, forcibly applying a current to the switching elements and stabilizing the threshold value Vth.

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  • Crystallography & Structural Chemistry (AREA)
  • Physics & Mathematics (AREA)
  • Computer Hardware Design (AREA)
  • General Physics & Mathematics (AREA)
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  • Liquid Crystal Display Device Control (AREA)
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Abstract

Système de commande réduisant la retenue et la rémanence de l'image imputable à la variation des caractéristiques d'un dispositif de commutation par effet du courant dans un dispositif d'affichage actif matriciel à cristaux liquides à deux terminaux. Le dispositif d'affichage à cristaux liquides comporte une série de lignes de données et de lignes de balayage, et des pixels à cristaux liquides disposés de manière à correspondre aux points d'intersection entre les lignes de données et les lignes de balayage. Chaque pixel à cristaux liquides compte au moins un dispositif de commutation à deux terminaux et est attaqué par un signal de balayage appliqué à la ligne de balayage et par un signal de données appliqué à la ligne de données. A ce stade, une période (27, 28, 32, 33) au cours de laquelle un courant est appliqué par le dispositif de commutation intervient avant une période de sélection (26, 31) du signal de balayage Ζ(n). Une période de rétention est en outre prévue après cette période de sélection.

Claims (9)

  1. Procédé de commande d'un dispositif d'affichage à cristaux liquides à matrice active de type à deux bornes qui comporte une pluralité de lignes de données et de lignes de balayage et des pixels de cristaux liquides prévus aux points d'intersection desdites lignes de données et desdites lignes de balayage, lesdits pixels de cristaux liquides comportant au moins un élément de commutation de type à deux bornes et étant commandés par un signal de balayage appliqué aux lignes de balayage et par un signal de données appliqué aux lignes de données, dans lequel chaque signal de balayage d'une ligne de balayage respective comporte des périodes de sélection pour écrire une charge électrique qui doit être stockée dans les pixels de cristaux liquides correspondants, des périodes d'application de courant pour appliquer un courant aux éléments de commutation de type à deux bornes correspondants précédant lesdites périodes de sélection et des périodes de maintien pour maintenir la charge électrique desdits pixels de cristaux liquides suivant lesdites périodes de sélection, dans lequel
       la partie de signal de balayage précédant une période de sélection respective comprend une ou plusieurs périodes (29, 30, 40) d'application d'un potentiel sans courant aux éléments de commutation de type à deux bornes insérées entre des périodes successives parmi une pluralité de périodes d'application de courant correspondantes (26, 28, 36) et/ou entre ladite période de sélection et une période d'application de courant précédente (38) ou comprend une ou plusieurs périodes d'application de courant (34) pendant lesquelles le potentiel de tension reste à une valeur donnée pendant un temps plus long que la durée de la période de sélection.
  2. Procédé de commande d'un dispositif d'affichage à cristaux liquides à matrice active de type à deux bornes selon la revendication 1, dans lequel ledit signal de balayage comporte des premières périodes de sélection pour appliquer une tension d'une première polarité auxdits pixels d'affichage à cristaux liquides et auxdits éléments de commutation de type à deux bornes et des secondes périodes de sélection pour appliquer une tension d'une seconde polarité à ceux-ci, et dans lequel les périodes d'application de courant comprennent l'application d'une tension d'une polarité opposée à celle de la tension de la période de sélection respectivement suivante auxdits éléments de commutation de type à deux bornes.
  3. Procédé de commande d'un dispositif d'affichage à cristaux liquides à matrice active de type à deux bornes selon la revendication 2, dans lequel les périodes d'application de courant comprennent l'application d'une tension ayant un potentiel dont la valeur absolue est égale à la valeur absolue du potentiel desdites périodes de sélection.
  4. Procédé de commande d'un dispositif d'affichage à cristaux liquides à matrice active de type à deux bornes selon la revendication 1, dans lequel ledit signal de balayage comporte des premières périodes de sélection pour appliquer une tension d'une première polarité auxdits éléments de commutation de type à deux bornes et des secondes périodes de sélection pour appliquer une tension d'une seconde polarité à ceux-ci, et dans lequel les périodes d'application de courant précédant une période de sélection respective comprennent l'application d'une tension d'une polarité opposée à celle de la tension de ladite période de sélection et d'une tension d'une polarité identique à celle de ladite période de sélection auxdits éléments de commutation de type à deux bornes.
  5. Procédé de commande d'un dispositif d'affichage à cristaux liquides à matrice active de type à deux bornes selon la revendication 1, dans lequel ledit signal de balayage comporte des premières périodes de sélection pour appliquer une tension d'une première polarité auxdits éléments de commutation de type à deux bornes et des secondes périodes pour appliquer une tension d'une seconde polarité à ceux-ci, et dans lequel les périodes d'application de courant précédant une période de sélection respective comprennent l'application d'une tension dont la valeur absolue est supérieure à la valeur absolue du potentiel desdites périodes de sélection.
  6. Procédé de commande d'un dispositif d'affichage à cristaux liquides à matrice active de type à deux bornes selon la revendication 1, dans lequel les périodes d'application de courant dudit signal de balayage utilisent les périodes de sélection d'un signal de balayage qui est appliqué à d'autres lignes de balayage.
  7. Procédé de commande d'un dispositif d'affichage à cristaux liquides à matrice active de type à deux bornes selon la revendication 1, dans lequel les périodes de sélection dudit signal de balayage sont continues avec les périodes d'application de courant qui précédent lesdites périodes de sélection.
  8. Procédé de commande d'un dispositif d'affichage à cristaux liquides à matrice active de type à deux bornes selon la revendication 1, dans lequel lorsqu'une valeur intermédiaire entre une valeur maximale et une valeur minimale prise par ledit signal de données pendant les périodes respectives est considérée comme étant un potentiel de référence, ledit potentiel de référence subit une variation pendant les périodes de sélection et pendant les périodes d'application de courant qui précèdent lesdites périodes de sélection.
  9. Dispositif d'affichage à cristaux liquides à matrice active de type à deux bornes qui comporte une pluralité de lignes de données (D1 ... DM) et de lignes de balayage (S1 ... Sn), des pixels de cristaux liquides (1) prévus aux points d'intersection desdites lignes de données et desdites lignes de balayage, lesdits pixels de cristaux liquides comportant au moins un élément de commutation de type à deux bornes (2), et comporte, de plus, des moyens de contrôle qui comprennent un circuit de contrôle (6) pour contrôler lesdites lignes de balayage, lesdites lignes de données, lesdits pixels de cristaux liquides et lesdits éléments de commutation de type à deux bornes, lesdits pixels d'affichage à cristaux liquides étant commandés par un signal de balayage appliqué aux lignes de balayage et par un signal de données appliqué aux lignes de données en réponse à un signal de contrôle provenant desdits moyens de contrôle, dans lequel lesdits moyens de contrôle comprennent des moyens de détermination de période d'application de courant (61) qui déterminent des périodes d'application de courant pour appliquer un courant auxdits éléments de commutation de type à deux bornes (2) précédant des périodes de sélection prédéterminées pendant lesquelles au moins ledit signal de balayage écrit une charge électrique destinée à être stockée dans lesdits pixels d'affichage à cristaux liquides, des moyens de détermination de polarité (62) qui déterminent la polarité du courant appliqué auxdits éléments de commutation de type à deux bornes (2) pendant lesdites périodes d'application de courant, des moyens de détermination de tension (63) qui déterminent une tension du courant appliqué aux éléments de commutation de type à deux bornes (2), et des moyens de détermination de nombre d'applications de courant (64) qui déterminent un nombre adéquat de fois supérieur à zéro d'application de courant auxdits éléments de commutation de type à deux bornes (2), de sorte que la partie de signal de balayage précédant une période de sélection respective comprend une ou plusieurs périodes (29, 30, 40) d'application d'un potentiel sans courant aux éléments de commutation de type à deux bornes insérées entre des périodes successives parmi une pluralité de périodes d'application de courant correspondantes (26, 28, 36) et/ou entre ladite période de sélection et une période d'application de courant précédente (38) ou comprend une ou plusieurs périodes d'application de courant (34) pendant lesquelles le potentiel de tension reste à une valeur donnée pendant un temps plus long que la durée de la période de sélection.
EP93913550A 1992-06-19 1993-06-21 Dispositif d'affichage actif matriciel a cristaux liquides a deux terminaux et systeme de commande de ce dispositif Expired - Lifetime EP0600096B1 (fr)

Applications Claiming Priority (3)

Application Number Priority Date Filing Date Title
JP184778/92 1992-06-19
JP18477892 1992-06-19
PCT/JP1993/000832 WO1994000791A1 (fr) 1992-06-19 1993-06-21 Dispositif d'affichage actif matriciel a cristaux liquides a deux terminaux et systeme de commande de ce dispositif

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EP0600096A1 EP0600096A1 (fr) 1994-06-08
EP0600096A4 EP0600096A4 (en) 1995-10-11
EP0600096B1 true EP0600096B1 (fr) 1999-01-27

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JP (1) JP3167135B2 (fr)
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Publication number Priority date Publication date Assignee Title
GB2295045B (en) * 1994-11-08 1998-07-15 Citizen Watch Co Ltd A liquid crystal display device and a method of driving the same
JP3485986B2 (ja) 1995-02-03 2004-01-13 シチズン時計株式会社 液晶表示装置及びその駆動方法

Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0321962A2 (fr) * 1987-12-23 1989-06-28 Seiko Epson Corporation Dispositif d'affichage élecrooptique à cristaux liquides à matrice active et sa méthode de commande

Family Cites Families (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS63198097A (ja) * 1987-02-13 1988-08-16 セイコーインスツルメンツ株式会社 非線形２端子型アクテイブマトリクス表示装置
JPS63269197A (ja) * 1987-04-28 1988-11-07 セイコーインスツルメンツ株式会社 液晶装置
JPH0266521A (ja) * 1988-09-01 1990-03-06 Seiko Epson Corp アクティブデバイス及びアクティブマトリクスディスプレイ及びアクティブマトリクスディスプレイの駆動方法
DE3814816A1 (de) * 1988-05-02 1989-11-16 Vdo Schindling Verfahren zur ansteuerung von anzeigevorrichtungen
JPH0258021A (ja) * 1988-08-23 1990-02-27 Seiko Epson Corp 液晶表示装置
TW200572B (fr) * 1991-03-20 1993-02-21 Seiko Epson Corp

Patent Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0321962A2 (fr) * 1987-12-23 1989-06-28 Seiko Epson Corporation Dispositif d'affichage élecrooptique à cristaux liquides à matrice active et sa méthode de commande

Also Published As

Publication number Publication date
EP0600096A4 (en) 1995-10-11
EP0600096A1 (fr) 1994-06-08
DE69323276D1 (de) 1999-03-11
WO1994000791A1 (fr) 1994-01-06
JP3167135B2 (ja) 2001-05-21
DE69323276T2 (de) 1999-06-02

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