Method for driving electro-optic device, electro-optic device, and electronic apparatus
A method for driving an electro-optic device includes a first and second electrode and a pair of substrates sandwiching an electro-optic layer driven by the first electrode. The method involves shifting one of two potentials input to at least one of the electrodes such that a potential difference between the first and second electrode where the potential input to the first electrode is higher than the potential input to the second electrode is larger than a potential difference between the first and second electrode where the potential input to the first electrode is lower than the potential input to the second electrode, when a gray-scale level where potential input to the first electrode is higher than potential input to the second electrode is equivalent to the gray-scale level where potential input to the first electrode is lower than potential input to the second electrode.
1. An electro-optic device comprising:
a first substrate;
a second substrate;
an electro-optic layer, wherein the first substrate and the second substrate sandwich the electro-optic layer;
a common electrode;
a pixel electrode, the common electrode and the pixel electrode being disposed on one of the first substrate and the second substrate, the common electrode being used to drive the electro-optic layer, the pixel electrode being disposed closer to the electro-optic layer than the first electrode, wherein a constant first signal potential is input to the common electrode and a second signal potential is input to the pixel electrode, and wherein according to an alternating current drive signal applied to the electro-optic layer, in a first period the second signal potential applied to the pixel electrode is higher than the first signal potential applied to the common electrode, and in a second period the second signal potential applied to the pixel electrode is lower than the first signal potential applied to the common electrode, the first signal potential remaining constant throughout the first and second periods; and
an insulating film formed between the common electrode and the pixel electrode, the pixel electrode being formed between the electro-optic layer and the insulating film, wherein:
(a) in the second period when the first signal potential is higher than the second signal potential:
(i) the common electrode and the pixel electrode have a first potential difference (B); and
(ii) the electro-optic device has a first gray-scale defined by a first white luminance;
(b) in the first period when the first signal potential is lower than the second signal potential:
(i) the common electrode and the pixel electrode have a second potential difference (A); and
(ii) the electro-optic device has a second gray-scale defined by a second white luminance; and
a control unit configured to shift the second signal potential such that the first potential difference (B) is larger than the second potential difference (A) when the first gray-scale is equivalent to the second gray-scale,
wherein the control unit is further configured to gradually increase a shift amount (ΔV=B−A) of the one of the first signal potential and the second signal potential based on an increase of the gray-scale level to suppress an image sticking in the electro-optic layer.
2. The electro-optic device of claim 1 , wherein the control unit is configured to shift the second signal potential over an entire range of a plurality of gray-scale levels.
3. The electro-optic device of claim 1 , wherein the control unit is configured to shift the second signal potential around a value corresponding to a maximum gray-scale level.
4. A method of operating an electro-optic device including: (a) a first substrate; (b) a second substrate; (c) an electro-optic layer, wherein the first substrate and the second substrate sandwich the electro-optic layer, (d) a common electrode; and (e) a pixel electrode, the common electrode and the pixel electrode being disposed on one of the first substrate and the second substrate, the common electrode being used to drive the electro-optic layer, the pixel electrode being disposed closer to the electro-optic layer than the common electrode, wherein a constant first signal potential is input to the common electrode and a second signal potential is input to the pixel electrode, and wherein according to an alternating current drive signal applied to the electro-optic layer, in a first period the second signal potential applied to the pixel electrode is higher than the first signal potential applied to the common electrode, and in a second period the second signal potential applied to the pixel electrode is lower than the first signal potential applied to the common electrode, the first signal potential remaining constant throughout the first and second periods; and an insulating film formed between the common electrode and the pixel electrode, the pixel electrode being formed between the electro-optic layer and the insulating film, wherein: (a) in the second period when the first signal potential is higher than the second signal potential: (i) the common electrode and the pixel electrode have a first potential difference (B); and (ii) the electro-optic device has a first gray-scale defined by a first white luminance; (b) in the first period when the first signal potential is lower than the second signal potential: (i) the common electrode and the pixel electrode have a second potential difference (A); and (ii) the electro-optic device has a second gray-scale defined by a second white luminance, the method comprising:
causing a control unit to shift the second signal potential such that the first potential difference (B) is larger than the second potential difference (A) when the first gray-scale is equivalent to the second gray-scale, wherein the control unit is configured to gradually increase a shift amount (ΔV=B−A) of the second signal potential based on an increase of the gray-scale level to suppress an image sticking in the electro-optic layer.
5. The method of claim 4 , which includes causing the control unit to shift the second signal potential over an entire range of a plurality of gray-scale levels.
6. The method of claim 4 , which includes causing the control unit to shift the second signal potential around a value corresponding to a maximum gray-scale level.
7. An electronic apparatus comprising:
a first substrate;
a second substrate;
an electro-optic layer, wherein the first substrate and the second substrate sandwich the electro-optic layer;
a common electrode;
a pixel electrode, the common electrode and the pixel electrode being disposed on one of the first substrate and the second substrate, the common electrode being used to drive the electro-optic layer, the pixel electrode being disposed closer to the electro-optic layer than the common electrode, wherein a constant first signal potential is input to the common electrode and a second signal potential is input to the pixel electrode, and wherein according to an alternating current drive signal applied to the electro-optic layer, in a first period the second signal potential applied to the pixel electrode is higher than the first signal potential applied to the common electrode, and in a second period the second signal potential applied to the pixel electrode is lower than the first signal potential applied to the common electrode, the first signal potential remaining constant throughout the first and second periods; and
an insulating film formed between the common electrode and the pixel electrode, the pixel electrode being formed between the electro-optic layer and the insulating film, wherein:
(a) in the second period when the first signal potential is higher than the second signal potential:
(i) the common electrode and the pixel electrode have a first potential difference (B); and
(ii) the electro-optic device has a first gray-scale defined by a first white luminance;
(b) in the first period when the first signal potential is lower than the second signal potential:
(i) the common electrode and the pixel electrode have a second potential difference (A); and
(ii) the electro-optic device has a second gray-scale defined by a second white luminance; and
a control unit configured to shift the second signal potential such that the first potential difference (B) is larger than the second potential difference (A) when the first gray-scale is equivalent to the second gray-scale, wherein the control unit is further configured to gradually increase a shift amount (ΔV=B−A) of the second signal potential based on an increase of the gray-scale level to suppress an image sticking in the electro-optic layer.
8. The electronic apparatus of claim 7 , wherein the control unit is configured to shift the second signal potential over an entire range of a plurality of gray-scale levels.
9. The electronic apparatus of claim 7 , wherein the control unit is configured to shift the second signal potential around a value corresponding to a maximum gray-scale level.