Liquid crystal device, driving method thereof, and electronic apparatus

A liquid crystal device comprising:

• a pixel electrode;
• a switching element which is electrically connected to the pixel electrode;
• a counter electrode which is disposed to be opposed to the pixel electrode and to which a counter electrode potential is applied;
• a liquid crystal layer which is provided between the pixel electrode and the counter electrode;
• a first alignment film which is provided between the liquid crystal layer and the pixel electrode;
• a first dielectric layer which is provided between the first alignment film and the pixel electrode and is made of silicon oxide;
• a second alignment film which is provided between the liquid crystal layer and the counter electrode;
• and
• a second dielectric layer which is provided between the second alignment film and the counter electrode, is made of silicon oxide, and has a thickness more than that of the first dielectric layer,
• wherein a high potential and a low potential relative to the counter electrode potential are alternately applied to the pixel electrode through the switching element, and
• wherein the counter electrode potential is set to be higher 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.

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 SiO2;
• 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 SiO2,
• 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 when 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 such as 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.

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 SiO2;
• and
• a second dielectric film which is provided between the counter electrode and the second alignment film, has a film thickness more than that of the first dielectric film, has a specific resistance higher than that of the liquid crystal layer, and is made of SiO2,
• 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 when 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 such as 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 shorter than the length of the second duration.

A method of driving a liquid crystal device,

• the liquid crystal device including a pixel electrode, a switching element which is electrically connected to the pixel electrode, a counter electrode which is disposed to be opposed to the pixel electrode and to which a counter electrode potential is applied, a liquid crystal layer which is provided between the pixel electrode and the counter electrode, a first alignment film which is provided between the liquid crystal layer and the pixel electrode, a first dielectric layer which is provided between the first alignment film and the pixel electrode and is made of silicon oxide, a second alignment film which is provided between the liquid crystal layer and the counter electrode, and a second dielectric layer which is provided between the second alignment film and the counter electrode, is made of silicon oxide, and has a thickness less than that of the first dielectric layer,
• the driving method comprising:
• applying alternately a high potential and a low potential relative to the counter electrode potential to the pixel electrode through the switching element;
• and
• setting the counter electrode potential such that the potential is 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.

A method of driving a liquid crystal device,

• the liquid crystal device including 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 SiO2, 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 SiO2,
• the driving method comprising:
• applying a counter electrode potential, which is set to reduce flicker caused by a parasitic capacitance of the switching element, to the counter electrode;
• applying alternately a positive voltage and a negative voltage to the pixel electrode when 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
• setting, in predetermined durations such as a first duration during which the positive voltage is applied and a second duration during which the negative voltage is applied, a length of the first duration such that the length is longer than a length of the second duration.

A method of driving a liquid crystal device,

• the liquid crystal device including 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 SiO2, and a second dielectric film which is provided between the counter electrode and the second alignment film, has a film thickness more than that of the first dielectric film, has a specific resistance higher than that of the liquid crystal layer, and is made of SiO2,
• the driving method comprising:
• applying a counter electrode potential, which is set to reduce flicker caused by a parasitic capacitance of the switching element, to the counter electrode;
• applying alternately a positive voltage and a negative voltage to the pixel electrode when 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
• setting, in predetermined durations such as a first duration during which the positive voltage is applied and a second duration during which the negative voltage is applied, a length of the first duration such that the length is shorter than a length of the second duration.