Liquid crystal device, liquid crystal device driving method, and electronic apparatus

Abstract

In a liquid crystal device according to the invention, a pre-tilt angle of a liquid crystal layer is greater on an opposing electrode side than on a pixel electrode side. A high potential and a low potential relative to an opposing electrode potential are alternately applied to pixel electrodes through switching elements; and the opposing electrode potential is higher than a standard potential, the standard potential being a potential in which the average potential between the high potential and the low potential has been shifted by an amount equivalent to the average value of the amount of change in the potential of the pixel electrodes caused by parasitic capacitance in the switching elements when the high potential is applied to the pixel electrodes and the amount of change in the potential of the pixel electrodes caused by parasitic capacitance when the low potential is applied to the pixel electrodes.

1 . A liquid crystal device comprising:
 pixel electrodes;   switching elements electrically connected to the pixel electrodes;   an opposing electrode, disposed opposing the pixel electrodes, to which an opposing electrode potential is applied;   a liquid crystal layer provided between the pixel electrodes and the opposing electrode;   a first orientation film provided between the liquid crystal layer and the pixel electrodes; and   a second orientation film provided between the liquid crystal layer and the opposing electrode,   wherein a pre-tilt angle formed by the director of the liquid crystal layer and the thickness direction of the liquid crystal layer is greater on the opposing electrode side than on the pixel electrode side;   a high potential and a low potential relative to the opposing electrode potential are alternately applied to the pixel electrodes through the switching elements; and   the opposing electrode potential is higher than a standard potential, the standard potential being a potential in which the average potential between the high potential and the low potential has been shifted, by an amount equivalent to the average value of the amount of change in the potential of the pixel electrodes caused by parasitic capacitance in the switching elements when the high potential is applied to the pixel electrodes and the amount of change in the potential of the pixel electrodes caused by parasitic capacitance when the low potential is applied to the pixel electrodes.   
     
     
         2 . A liquid crystal device comprising:
 pixel electrodes;   switching elements electrically connected to the pixel electrodes;   an opposing electrode, disposed opposing the pixel electrodes, to which an opposing electrode potential is applied;   a liquid crystal layer provided between the pixel electrodes and the opposing electrode;   a first orientation film provided between the liquid crystal layer and the pixel electrodes; and   a second orientation film provided between the liquid crystal layer and the opposing electrode,   wherein a pre-tilt angle formed by the director of the liquid crystal layer and the thickness direction of the liquid crystal layer is greater on the pixel electrode side than on the opposing electrode side;   a high potential and a low potential relative to the opposing electrode potential are alternately applied to the pixel electrodes through the switching elements; and   the opposing electrode potential is lower than a standard potential, the standard potential being a potential in which the average potential between the high potential and the low potential has been shifted by an amount equivalent to the average value of the amount of change in the potential of the pixel electrodes caused by parasitic capacitance in the switching elements when the high potential is applied to the pixel electrodes and the amount of change in the potential of the pixel electrodes caused by parasitic capacitance when low potential is applied to the pixel electrodes.   
     
     
         3 . A liquid crystal device comprising:
 an element substrate including multiple scanning lines and multiple data lines, and switching elements and pixel electrodes provided in correspondence to the intersections between the scanning lines and the data lines;   an opposing substrate, disposed opposing the element substrate, that includes an opposing electrode;   a liquid crystal layer held between the element substrate and the opposing substrate;   a first orientation film provided on the side of the element substrate that faces the liquid crystal layer; and   a second orientation film provided on the side of the opposing substrate that faces the liquid crystal layer,   wherein a first pre-tilt angle in the first orientation film is set to be lower than a second pre-tilt angle in the second orientation film;   an opposing electrode potential set so as to reduce flicker caused by parasitic capacitance in the switching elements is applied to the opposing electrode;   assuming that a high voltage relative to the opposing electrode potential is positive polarity and a low voltage relative to the opposing electrode potential is negative polarity, the positive polarity voltage and the negative polarity voltage are applied alternately to the pixel electrodes; and   in a predetermined interval made up of a first interval in which the positive polarity voltage is applied and a second interval in which the negative polarity voltage is applied, the length of the first interval is set to be shorter than the length of the second interval.   
     
     
         4 . A liquid crystal device comprising:
 an element substrate including multiple scanning lines and multiple data lines, and switching elements and pixel electrodes provided in correspondence to the intersections between the scanning lines and the data lines;   an opposing substrate, disposed opposing the element substrate, that includes an opposing electrode;   a liquid crystal layer held between the element substrate and the opposing substrate;   a first orientation film provided on the side of the element substrate that faces the liquid crystal layer; and   a second orientation film provided on the side of the opposing substrate that faces the liquid crystal layer,   wherein a first pre-tilt angle in the first orientation film is set to be greater than a second pre-tilt angle in the second orientation film;   an opposing electrode potential set so as to reduce flicker caused by parasitic capacitance in the switching elements is applied to the opposing electrode;   assuming that a high voltage relative to the opposing electrode potential is positive polarity and a low voltage relative to the opposing electrode potential is negative polarity, the positive polarity voltage and the negative polarity voltage are applied alternately to the pixel electrodes; and   in a predetermined interval made up of a first interval in which the positive polarity voltage is applied and a second interval in which the negative polarity voltage is applied, the length of the first interval is set to be longer than the length of the second interval.   
     
     
         5 . The liquid crystal device according to  claim 1 , wherein the pixel electrodes are configured of aluminum, and the opposing electrode is configured of indium tin oxide. 
     
     
         6 . The liquid crystal device according to  claim 2 , wherein the pixel electrodes are configured of aluminum, and the opposing electrode is configured of indium tin oxide. 
     
     
         7 . The liquid crystal device according to  claim 3 , wherein the pixel electrodes are configured of aluminum, and the opposing electrode is configured of indium tin oxide. 
     
     
         8 . The liquid crystal device according to  claim 4 , wherein the pixel electrodes are configured of aluminum, and the opposing electrode is configured of indium tin oxide. 
     
     
         9 . The liquid crystal device according to  claim 1 , wherein when the pre-tilt angle in the vicinity of the second orientation film is 6° greater than the pre-tilt angle in the vicinity of the first orientation film, the ratio of the absolute value of the potential difference between the opposing electrode potential and the low potential to the absolute value of the potential difference between the opposing electrode potential and the high potential is set to a range from more than or equal to 49/51 and less than or equal to 52/48. 
     
     
         10 . The liquid crystal device according to  claim 2 , wherein when the pre-tilt angle in the vicinity of the second orientation film is 6° greater than the pre-tilt angle in the vicinity of the first orientation film, the ratio of the absolute value of the potential difference between the opposing electrode potential and the low potential to the absolute value of the potential difference between the opposing electrode potential and the high potential is set to a range from more than or equal to 49/51 and less than or equal to 52/48. 
     
     
         11 . A liquid crystal device driving method,
 wherein the liquid crystal device includes pixel electrodes, switching elements electrically connected to the pixel electrodes, an opposing electrode disposed opposing the pixel electrodes and to which an opposing electrode potential is applied, a liquid crystal layer provided between the pixel electrodes and the opposing electrode, a first orientation film provided between the liquid crystal layer and the pixel electrodes, and a second orientation film provided between the liquid crystal layer and the opposing electrode, with a pre-tilt angle formed by the director of the liquid crystal layer and the thickness direction of the liquid crystal layer greater on the opposing electrode side than on the pixel electrode side, and   the driving method comprises:   alternatively applying a high potential and a low potential relative to the opposing electrode potential to the pixel electrodes through the switching elements; and   setting the opposing electrode potential to be lower than a standard potential, the standard potential being a potential in which the average potential between the high potential and the low potential has been shifted by an amount equivalent to the average value of the amount of change in the potential of the pixel electrodes caused by parasitic capacitance in the switching elements when the high potential is applied to the pixel electrodes and the amount of change in the potential of the pixel electrodes caused by parasitic capacitance when low potential is applied to the pixel electrodes.   
     
     
         12 . A liquid crystal device driving method,
 wherein the liquid crystal device includes an element substrate having multiple scanning lines and multiple data lines as well as switching elements and pixel electrodes provided in correspondence to the intersections between the scanning lines and the data lines, an opposing substrate disposed opposing the element substrate that includes an opposing electrode, a liquid crystal layer held between the element substrate and the opposing substrate, a first orientation film provided on the side of the element substrate that faces the liquid crystal layer, and a second orientation film provided on the side of the opposing substrate that faces the liquid crystal layer, with a first pre-tilt angle in the first orientation film set to be lower than a second pre-tilt angle in the second orientation film, and   the driving method comprises:   applying an opposing electrode potential set so as to reduce flicker caused by parasitic capacitance in the switching elements to the opposing electrode;   applying a positive polarity voltage and a negative polarity voltage alternately to the pixel electrodes, the positive polarity voltage being a high voltage relative to the opposing electrode potential and the negative polarity voltage being a low voltage relative to the opposing electrode potential; and   setting, in a predetermined interval made up of a first interval in which the positive polarity voltage is applied and a second interval in which the negative polarity voltage is applied, the length of the first interval to be shorter than the length of the second interval.   
     
     
         13 . A liquid crystal device driving method,
 wherein the liquid crystal device includes an element substrate having multiple scanning lines and multiple data lines as well as switching elements and pixel electrodes provided in correspondence to the intersections between the scanning lines and the data lines, an opposing substrate disposed opposing the element substrate that includes an opposing electrode, a liquid crystal layer held between the element substrate and the opposing substrate, a first orientation film provided on the side of the element substrate that faces the liquid crystal layer, and a second orientation film provided on the side of the opposing substrate that faces the liquid crystal layer, with a first pre-tilt angle in the first orientation film set to be greater than a second pre-tilt angle in the second orientation film, and   the driving method comprises:   applying an opposing electrode potential set so as to reduce flicker caused by parasitic capacitance in the switching elements to the opposing electrode;   applying a positive polarity voltage and a negative polarity voltage alternately to the pixel electrodes, the positive polarity voltage being a high voltage relative to the opposing electrode potential and the negative polarity voltage being a low voltage relative to the opposing electrode potential; and   setting, in a predetermined interval made up of a first interval in which the positive polarity voltage is applied and a second interval in which the negative polarity voltage is applied, the length of the first interval to be longer than the length of the second interval.   
     
     
         14 . The liquid crystal device driving method according to  claim 12 , wherein the ratio between the length of the first interval and the length of the second interval is set to a range that is greater than 50.0/50.0 and less than or equal to 52.0/48.0 when the first pre-tilt angle is set so as to be 6° less than the second pre-tilt angle. 
     
     
         15 . An electronic apparatus comprising the liquid crystal device according to  claim 1 . 
     
     
         16 . An electronic apparatus comprising the liquid crystal device according to  claim 2 . 
     
     
         17 . An electronic apparatus comprising the liquid crystal device according to  claim 3 . 
     
     
         18 . An electronic apparatus comprising the liquid crystal device according to  claim 4 .