Driving technique for activating liquid crystal device
AssigneeMatsushita Electric Industrial Co., Ltd.
InventorsMika Nakamura, Katsumi Adachi, Kiyohiro Kawasaki, Katsuji Hattori
Life of this patent
Estimating the term…
Abstract
To provide a high-response and wide-viewing-angle liquid crystal panel capable of causing a transition of liquid crystal, which is called the OCB mode, into a bend configuration in a short time, there is provided a period in which a potential difference higher than that in a normal image display period is continuously applied between gate lines and opposing electrodes or between pixel electrodes and the opposing electrodes of the liquid crystal panel. Also, ingenuities are exercised on the period in which the potential difference is continuously applied between them and on the structure of picture elements.
Claims47
A method for driving a liquid crystal device to cause transition from a splay configuration to a bend configuration of a liquid crystal layer, located between a first substrate on which thin film transistors, gate lines and pixel electrodes are located in a matrix and a second substrate on which an opposing electrode is located, the method comprising:
- applying a primary potential difference, different from a potential difference in a normal image display period, between the pixel electrode on the first substrate and the opposing electrode on the second substrate;
- applying a secondary potential difference smaller than the primary potential difference;
- and
- alternately applying a primary potential difference and applying a secondary potential difference at least one time each during a repeatable cycle period, the length of a primary potential difference application period being from at least 50% to no more than 95% of the length of one repeatable cycle period.
A driving circuit of a liquid crystal device to cause transition from a splay configuration to a bend configuration of a liquid crystal layer, located between a first substrate on which thin film transistors, gate lines and pixel electrodes are located in a matrix and a second substrate on which an opposing electrode is located, the driving circuit comprising:
- primary potential difference application means for applying a primary potential difference, different from a potential difference in a normal image display period, between the pixel electrode on the first substrate and the opposing electrode on the second substrate;
- secondary potential difference application means for applying a secondary potential difference smaller than the primary potential difference;
- and
- repeat control means for alternately executing the primary potential difference application means and the secondary potential difference application means at least one time each during a repeated period, the length of a primary potential difference application period being in the range of from at least 50% to no more than 95% of a length of one repeated period.
A method for driving a liquid crystal device to cause transition from a splay configuration to a bend configuration of a liquid crystal layer, located between a first substrate on which thin film transistors, gate lines and pixel electrodes are located in a matrix and a second substrate on which an opposing electrode is located, the method comprising:
- applying a primary potential difference, different from a potential difference in a normal image display period, between the pixel electrode and the opposing electrode;
- applying a secondary potential difference smaller than the primary potential difference;
- alternately executing applying a primary potential difference and applying a secondary potential difference at least one time each;
- and
- applying to source lines a potential in which a pixel electrode potential variation is reflected in an opposing electrode potential, the pixel electrode potential variation being induced by potential variation of the gate lines when the pixel transistor is switched to OFF from ON in applying a secondary potential difference, to charge the pixel electrodes.
A driving circuit of a liquid crystal device to cause transition from a splay configuration to a bend configuration of a liquid crystal layer, located between a first substrate on which thin film transistors, gate lines and pixel electrodes are located in a matrix and a second substrate on which an opposing electrode is located, the driving circuit comprising:
- primary potential difference application means for applying a primary potential difference, different from a potential difference in a normal image display period, between the pixel electrode and the opposing electrode;
- secondary potential difference application means for applying a secondary potential difference smaller than the primary potential difference;
- repeat control means for alternately operating the primary potential difference application means and the secondary potential difference application means at least one time each;
- and
- charging means for applying to source lines a potential in which a pixel electrode potential variation is reflected in an opposing electrode potential, the pixel electrode potential variation being induced by potential variation of the gate lines when the pixel transistor is switched to OFF from ON in a secondary potential difference application period, to charge the pixel electrodes.
A method for driving a liquid crystal device to cause transition from a splay configuration to a bend configuration of a liquid crystal layer, located between a first substrate on which thin film transistors, gate lines and pixel electrodes are located in a matrix and a second substrate on which an opposing electrode is located, the method comprising:
- applying a primary potential difference, different from a potential difference in a normal image display period, between the pixel electrode and the opposing electrode;
- applying a secondary potential difference smaller than the primary potential difference;
- alternately executing applying a primary potential difference and applying a secondary potential difference at least one time each;
- and
- applying to source lines a potential in which a pixel electrode potential variation is reflected in the opposing electrode potential, the pixel electrode potential variation being induced by a potential variation of the gate lines when the pixel transistor is switched to OFF from ON while applying a secondary potential difference, to charge the pixel electrodes,
- wherein the potential of the source lines is modulated to a potential different from a potential difference in a period during which the secondary potential difference is applied so that the primary potential difference can be further increased in a period during which the primary potential difference is applied.
A driving circuit of a liquid crystal device to cause transition from a splay configuration to a bend configuration of a liquid crystal layer, located between a first substrate on which thin film transistors, gate lines and pixel electrodes are located in a matrix and a second substrate on which an opposing electrode is located, the driving circuit comprising:
- primary potential difference application means for applying a primary potential difference, different from a potential difference in a normal image display period, between the pixel electrode and the opposing electrode;
- secondary potential difference application means for applying a secondary potential difference smaller than the primary potential difference;
- repeat control means for alternately operating the primary potential difference application means and the secondary potential difference application means at least one time each;
- and
- charging means for applying to source lines a potential in which a pixel electrode potential variation is reflected in the opposing electrode potential, the pixel electrode potential variation being induced by a potential variation of the gate lines when the pixel transistor is switched to OFF from ON in the secondary potential difference application period, to charge the pixel electrodes,
- wherein the potential of the source lines is modulated to a potential different from a potential difference in a period during which the secondary potential difference is applied so that the primary potential difference can be further increased in a period during which the primary potential difference is applied.
A method for driving a liquid crystal device to cause transition from a splay configuration to a bend configuration of a liquid crystal layer, located between a first substrate on which thin film transistors and pixel electrodes are located in a matrix and a second substrate on which an opposing electrode is located, the method comprising:
- applying a primary potential difference, different from a potential difference in a normal image display period, between the pixel electrode on the first substrate and the opposing electrode on the second substrate;
- and
- applying a secondary potential difference smaller than the primary potential difference;
- alternately controlling applying a primary potential difference and applying a secondary potential difference at least one time each,
- wherein during alternately controlling applying a primary potential difference and applying a secondary potential difference, applying a secondary potential difference is performed first.
A driving circuit of a liquid crystal device to cause transition from a splay configuration to a bend configuration of a liquid crystal layer, located between a first substrate on which thin film transistors and pixel electrodes are located in a matrix and a second substrate on which an opposing electrode is located, the driving circuit comprising:
- primary potential difference application means for applying a primary potential difference, different from a potential difference in a normal image display period, between the pixel electrode on the first substrate and the opposing electrode on the second substrate;
- secondary potential difference application means for applying a secondary potential difference smaller than the primary potential difference;
- and
- repeat control means for allowing the secondary potential difference application means to operate first and allowing the primary potential difference application means and the secondary potential difference application means to alternately operate at least one time each.
A method for driving a liquid crystal device to cause transition from a splay configuration to a bend configuration of a liquid crystal layer, located between a first substrate on which thin film transistors and pixel electrodes are located in a matrix and a second substrate on which an opposing electrode is located, the method comprising:
- applying a primary potential difference, different from a potential difference in a normal image display period, between the pixel electrode on the first substrate and the opposing electrode on the second substrate;
- applying a secondary potential difference smaller than the primary potential difference;
- alternately executing applying a primary potential difference and applying a secondary potential difference at least one time each;
- and
- applying a larger potential difference, of the potential differences applied to the liquid crystal layer in the normal image information display period, to the liquid crystal layer at least one field during a period from after completion of alternate execution of applying a primary potential difference and the applying a secondary potential difference at least one time each until the shift to the normal image information display period is achieved.
A driving circuit of a liquid crystal device to cause transition from a splay configuration to a bend configuration of a liquid crystal layer, located between a first substrate on which thin film transistors and pixel electrodes are located in a matrix and a second substrate on which an opposing electrode is located, the driving circuit comprising:
- primary potential difference application means for applying a primary potential difference, different from a potential difference in a normal image display period, between the pixel electrode on the first substrate and the opposing electrode on the second substrate;
- and
- secondary potential difference application means for applying a secondary potential difference smaller than the primary potential difference;
- means for alternately controlling the primary potential difference application means and the secondary potential difference application means at least one time each, and
- high-potential-difference-for-transition application means for applying a relatively larger potential difference of the potential differences applied to the liquid crystal layer in the normal image information display period, to at least one field of the liquid crystal layer during a period from after completion of alternately executing of said means for applying a primary potential difference and said means for applying a secondary potential difference at least one time each until the shift to the normal image information display period is achieved.
A method for driving a liquid crystal device to cause transition from a splay configuration to a bend configuration of a liquid crystal layer, located between a first substrate on which thin film transistors and pixel electrodes are located in a matrix and a second substrate on which an opposing electrode is located, the method comprising:
- applying a primary potential difference, different from a potential difference in a normal image display period, between the pixel electrode on the first substrate and the opposing electrode on the second substrate;
- applying a secondary potential difference smaller than the primary potential difference;
- allowing applying a secondary potential difference application to be initiated first, and alternately operating applying a primary potential difference and applying a secondary potential difference at least one time each, and
- controlling activation of parts of the liquid crystal device in advance, to keep the aligned state of the liquid crystal layer from being disarranged to an excessive degree after power is turned on.
A driving circuit of a liquid crystal device to cause transition from a splay configuration to a bend configuration of a liquid crystal layer, located between a first substrate on which thin film transistors and pixel electrodes are located in a matrix and a second substrate on which an opposing electrode is located, the driving circuit comprising:
- primary potential difference application means for applying a primary potential difference, different from a potential difference in a normal image display period, between the pixel electrode on the first substrate and the opposing electrode on the second substrate;
- secondary potential difference application means for applying a secondary potential difference smaller than the primary potential difference;
- repeat control means for allowing the means for secondary potential difference to be initiated first, and alternately operating the means for primary potential difference and the means for secondary potential difference at least one time each, and
- activation controlling means for controlling activation of parts of the liquid crystal device in advance, to keep an aligned state of the liquid crystal layer from being disarranged to an excessive degree after power is turned on.
A method for driving a liquid crystal device to cause transition from a splay configuration to a bend configuration of a liquid crystal layer, located between a first substrate on which thin film transistors and pixel electrodes are located in a matrix and a second substrate on which an opposing electrode is located, the method comprising:
- continuously applying a potential difference, different from a potential difference in a normal image display period, between the pixel electrode on the first substrate and the opposing electrode on the second substrate, wherein,
- storage capacities connected to the pixel electrodes are formed between the pixel electrodes and common electrodes having potentials common to all the pixel electrodes, so that, by means of a ratio between pixel electrode capacities including the storage capacities and parasitic capacities between gate lines of the thin film transistors and the pixel electrodes, potential variation of the pixel electrodes accompanied by potential variation of the common electrodes results in a potential difference.
A method for driving a liquid crystal device to cause transition from a splay configuration to a bend configuration of a liquid crystal layer, located between a first substrate on which thin film transistors and pixel electrodes are located in a matrix and a second substrate on which an opposing electrode is located, the method comprising:
- continuously applying a potential difference, different from a potential difference in a normal image display period, between the pixel electrode on the first substrate and the opposing electrode on the second substrate, wherein,
- storage capacities connected to the pixel electrodes are formed between the pixel electrodes and the gate lines one line front or behind, so that, by means of a ratio between pixel electrode capacities including the storage capacities and capacities between parasitic gate lines of the thin-film transistors and the pixel electrodes, potential variation of the pixel electrodes accompanied by potential variation of the gate lines one line front or behind results in the potential difference.
A liquid crystal device having a driving circuit to cause transition from a splay configuration to a bend configuration of a liquid crystal layer, located between a first substrate on which thin film transistors and pixel electrodes are located in a matrix and a second substrate on which an opposing electrode is located, to a bend configuration, the liquid crystal device comprising:
- different potential continuous application means for continuously applying a potential difference, different from a potential difference in a normal image display period, between the pixel electrode on the first substrate and the opposing electrode on the second substrate, wherein
- the different potential difference continuous application means comprises means for varying a common electrode potential by using means for continuously applying a different potential difference, wherein storage capacities connected to the pixel electrodes are formed between the pixel electrodes and common electrodes having potentials common to all the pixel electrodes, so that, by means of a ratio between pixel electrode capacities including the storage capacities and parasitic capacities between gate lines of the thin-film transistors and the pixel electrodes, potential variation of the pixel electrodes accompanied by potential variation of the common electrodes results in a potential difference.
A liquid crystal device having a driving circuit to cause transition from a splay configuration to a bend configuration of a liquid crystal layer, located between a first substrate on which thin film transistors and pixel electrodes are formed in a matrix and a second substrate on which an opposing electrode is located, the liquid crystal device comprising:
- different potential difference continuous application means for continuously applying a potential difference, different from a potential difference in a normal image display period, between the pixel electrode on the first substrate and the opposing electrode on the second substrate, wherein,
- the different potential difference continuous application means comprises means for varying a gate line potential by using means for continuously applying a different potential difference, wherein storage capacities connected to the pixel electrodes are formed between the pixel electrodes and the gate lines one line front or behind, so that, by means of a ratio between pixel electrode capacities including the storage capacities and parasitic capacities between gate lines of the thin-film transistors and the pixel electrodes, potential variation of the pixel electrodes accompanied by the potential variation of the gate lines one line front or behind results in a potential difference.
Dependencies are inferred from the claim text.