Liquid crystal device, driving method thereof, and electronic apparatus capable of improving display quality by suppressing occurrence of display defect
In a liquid crystal device according to the embodiment of the invention, a high potential and a low potential relative to the counter electrode potential are alternately applied to the pixel electrode through the switching element. Here, the counter electrode potential is set to be lower than a reference potential, when the reference potential is an electric potential which is obtained by shifting an average electric potential between the high potential and the low potential by an average value between an amount of change in an electric potential of the pixel electrode, caused by a parasitic capacitance of the switching element when the high potential is being applied to the pixel electrode, and an amount of change in the electric potential of the pixel electrode caused by the parasitic capacitance when the low potential is being applied to the pixel electrode.
1. A liquid crystal device, comprising:
an element substrate which has a plurality of scan lines and a plurality of data lines, and has a pixel electrode and a switching element provided to correspond to an intersection point between the scan line and the data line;
a counter substrate which is disposed to be opposed to the element substrate and has a counter electrode;
a liquid crystal layer which is sandwiched between the element substrate and the counter substrate;
a first alignment film which is provided on a side of the element substrate close to the liquid crystal layer;
a second alignment film which is provided on a side of the counter substrate close to the liquid crystal layer;
a first dielectric film which is provided between the pixel electrode and the first alignment film, has a film thickness less than that of the liquid crystal layer, has a specific resistance higher than that of the liquid crystal layer, and is made of silicon oxide; and
a second dielectric film which is provided between the counter electrode and the second alignment film, has a film thickness less than that of the first dielectric film, has a specific resistance higher than that of the liquid crystal layer, and is made of silicon oxide,
wherein a counter electrode potential, which is set to reduce flicker caused by a parasitic capacitance of the switching element, is applied to the counter electrode,
wherein a positive voltage and a negative voltage are alternately applied to the pixel electrode wherein the positive voltage is a high-potential voltage and the negative voltage is a low-potential voltage relative to the counter electrode potential as a reference, and
wherein in predetermined durations including a first duration during which the positive voltage is applied and a second duration during which the negative voltage is applied, the length of the first duration is set to be longer than the length of the second duration.
2. A liquid crystal device, comprising:
an element substrate which has a plurality of scan lines and a plurality of data lines, and has a pixel electrode and a switching element provided to correspond to an intersection point between the scan line and the data line;
a counter substrate which is disposed to be opposed to the element substrate and has a counter electrode;
a liquid crystal layer which is sandwiched between the element substrate and the counter substrate;
a first alignment film which is provided on a side of the element substrate close to the liquid crystal layer;
a second alignment film which is provided on a side of the counter substrate close to the liquid crystal layer;
a first dielectric film which is provided between the pixel electrode and the first alignment film, has a film thickness less than that of the liquid crystal layer, has a specific resistance higher than that of the liquid crystal layer, and is made of silicon oxide; and
a second dielectric film which is provided between the counter electrode and the second alignment film, has a film thickness less than that of the first dielectric film, has a specific resistance higher than that of the liquid crystal layer, and is made of silicon oxide,
wherein a counter electrode potential, which is set to reduce flicker caused by a parasitic capacitance of the switching element, is applied to the counter electrode,
a first voltage is applied to the pixel electrode in a first duration,
the first voltage is a positive voltage,
a second voltage is applied to the pixel electrode in a second duration that is next to the first duration,
the second voltage is different from the first voltage, and
wherein the first duration is longer than the second duration.
3. A liquid crystal device comprising:
an element substrate which has a plurality of scan lines and a plurality of data lines, and has a pixel electrode and a switching element provided to correspond to an intersection point between the scan line and the data line;
a counter substrate which is disposed to be opposed to the element substrate and has a counter electrode;
a liquid crystal layer which is sandwiched between the element substrate and the counter substrate;
a first alignment film which is provided on a side of the element substrate close to the liquid crystal layer;
a second alignment film which is provided on a side of the counter substrate close to the liquid crystal layer;
a first dielectric film which is provided between the pixel electrode and the first alignment film, has a film thickness less than that of the liquid crystal layer, has a specific resistance higher than that of the liquid crystal layer, and is made of silicon oxide; and
a second dielectric film which is provided between the counter electrode and the second alignment film, has a film thickness less than that of the first dielectric film, has a specific resistance higher than that of the liquid crystal layer, and is made of silicon oxide,
wherein a counter electrode potential, which is set to reduce flicker caused by a parasitic capacitance of the switching element, is applied to the counter electrode,
wherein a positive voltage duration and a negative voltage duration are alternately applied to the pixel electrode,
the positive voltage duration is a duration that includes a high-potential voltage is applied relative to the counter electrode potential as a reference,
the negative voltage duration is a duration that includes a low-potential voltage is applied relative to the counter electrode potential as a reference, and
wherein the positive voltage duration is longer than the negative voltage duration.
4. A liquid crystal device, comprising:
a liquid crystal panel including
an element substrate including
a plurality of scan lines and a plurality of data lines, and
a pixel electrode and a switching element corresponding to an intersection point of each of the scan lines and each of the data lines,
a counter substrate disposed to be opposed to the element substrate and including a counter electrode,
a liquid crystal layer between the element substrate and the counter substrate,
a first alignment film on a side of the element substrate close to the liquid crystal layer,
a second alignment film on a side of the counter substrate close to the liquid crystal layer,
a first dielectric film between the pixel electrode and the first alignment film, having a film thickness thinner than that of the liquid crystal layer and a specific resistance higher than that of the liquid crystal layer, and including silicon oxide, and
a second dielectric film between the counter electrode and the second alignment film, having a film thickness thinner than that of the first dielectric film and a specific resistance higher than that of the liquid crystal layer, and including silicon oxide;
a voltage generating circuit configured to generate a counter electrode potential, which is set to reduce flicker caused by a parasitic capacitance of the switching element, and to apply the counter electrode potential to the counter electrode; and
a control circuit configured to apply a first voltage and a second voltage alternately to the pixel electrode wherein the first voltage is a high-potential voltage and the second voltage is a low-potential voltage relative to the counter electrode potential as a reference, wherein
the control circuit is configured to set a length of a first duration, during which the first voltage is applied, to be longer than a length of a second duration, during which the second voltage is applied.
5. A liquid crystal device, comprising:
a liquid crystal panel including
an element substrate including
a plurality of scan lines and a plurality of data lines, and
a pixel electrode and a switching element provided to correspond to an intersection point of each of the scan lines and each of the data lines,
a counter substrate disposed to be opposed to the element substrate and including a counter electrode,
a liquid crystal layer between the element substrate and the counter substrate,
a first alignment film on a side of the element substrate close to the liquid crystal layer,
a second alignment film on a side of the counter substrate close to the liquid crystal layer,
a first dielectric film between the pixel electrode and the first alignment film, having a film thickness thinner than that of the liquid crystal layer and a specific resistance higher than that of the liquid crystal layer, and including silicon oxide, and
a second dielectric film between the counter electrode and the second alignment film, having a film thickness thinner than that of the first dielectric film and a specific resistance higher than that of the liquid crystal layer, and including silicon oxide;
a voltage generating circuit configured to generate a counter electrode potential, which is set to reduce flicker caused by a parasitic capacitance of the switching element, and to apply the counter electrode potential to the counter electrode; and
a control circuit configured to apply
a first voltage to the pixel electrode in a first duration, and
a second voltage to the pixel electrode in a second duration that is next to the first duration, wherein
the first voltage is a positive voltage,
the second voltage is a voltage different from the first voltage, and
the first duration is longer than the second duration.
6. A liquid crystal device, comprising:
a liquid crystal panel including
an element substrate including
a plurality of scan lines and a plurality of data lines, and
a pixel electrode and a switching element provided to correspond to an intersection point of each of the scan lines and each of the data lines,
a counter substrate disposed to be opposed to the element substrate and including a counter electrode,
a liquid crystal layer between the element substrate and the counter substrate,
a first alignment film on a side of the element substrate close to the liquid crystal layer,
a second alignment film on a side of the counter substrate close to the liquid crystal layer,
a first dielectric film between the pixel electrode and the first alignment film, having a film thickness thinner than that of the liquid crystal layer and a specific resistance higher than that of the liquid crystal layer, and including silicon oxide, and
a second dielectric film between the counter electrode and the second alignment film, having a film thickness thinner than that of the first dielectric film and a specific resistance higher than that of the liquid crystal layer, and including silicon oxide;
a voltage generating circuit configured to generate a counter electrode potential, which is set to reduce flicker caused by a parasitic capacitance of the switching element, and to apply the counter electrode potential to the counter electrode; and
a control circuit configured to apply a first voltage duration and a second voltage duration alternately to the pixel electrode, wherein
the first voltage duration is a duration including application of a high-potential voltage relative to the counter electrode potential as a reference,
the second voltage duration is a duration including application of a low-potential voltage relative to the counter electrode potential as a reference, and
the first voltage duration is longer than the second voltage duration.
7. The liquid crystal device according to claim 1 , wherein the pixel electrode is made of aluminum, and the counter electrode is made of indium tin oxide.
8. An electronic apparatus comprising the liquid crystal device according to claim 1 .