Method of driving electrophoretic display apparatus, electrophoretic display apparatus, and electronic device
View Patent ↗A method of driving an electrophoretic display apparatus, wherein during displaying an image on the display unit, executing a pixel electrode pulse driving in which a pulse periodically alternating between first and second potentials is input to the pixel electrode corresponding to the pixel of which a display state is changed, the first or second potential is input to the pixel electrode corresponding to the pixel of which a display state is not to be changed, and a potential equal to that of the pixel electrode corresponding to the pixel of which a display state is not to be changed is input to the common electrode.
1. A method of driving an electrophoretic display apparatus, the electrophoretic display apparatus including:
a display unit having a plurality of pixels;
a plurality of pixel electrodes, each of the plurality of pixel electrodes corresponding to one of the plurality of pixels;
a common electrode facing the plurality of pixel electrodes; and
an electrophoretic element disposed between the plurality of pixel electrodes and the common electrode, the electrophoretic element having electrophoretic particles,
the method comprising:
selecting one of a pixel electrode pulse driving or a common electrode pulse driving for displaying an image on the display unit based on a ratio of the pixels that are going to be updated by selected pulse;
executing the pixel electrode pulse driving in response to the pixel electrode pulse driving being selected for displaying the image on the display unit, the pixel electrode pulse driving including:
applying a pulse periodically alternating between a first and second potential to the pixel electrode belonging to the pixel of which a display state is changed,
maintaining application of a constant potential to the pixel electrode belonging to the pixel of which a display state is not to be changed, and
applying the constant potential to the common electrode; and
executing the common electrode pulse driving in response to the common electrode pulse driving being selected for displaying the image on the display unit, the common electrode pulse driving including:
applying the first or second potential corresponding to a display color after updating to each of the plurality of pixel electrodes, and
applying a pulse periodically alternating between the first and second potentials to the common electrode.
2. The method according to claim 1 , wherein the pixel electrode pulse driving is selected when the ratio of the pixels of which display states are updated is 50% or less of all the pixels.
3. The method according to claim 2 , wherein the electrophoretic display apparatus includes a coordinate input device for executing input by a pointing device, and the pixel electrode pulse driving is selected when a locus of the pointing device is displayed.
4. The method according to claim 1 , wherein the common electrode pulse driving is executed only when the ratio of the pixels of which display states are updated is 100%.
5. The method according to claim 1 , wherein first and second control lines connected to each of the plurality of pixels are formed in the display unit, and each of the plurality of pixels includes a pixel switching element, a latch circuit connected to the pixel switching element, and a switch circuit connected to an output terminal of the latch circuit and the first and second control lines, and
wherein in the pixel electrode pulse driving,
a pulse periodically alternating between the first and second potentials is input to the first or second control line connected to the pixel electrode belonging to the pixel of which a display state is changed, and the first or second potential equal to a potential of the common electrode is input to the first or second control line connected to the pixel electrode belonging to the pixel of which a display state is maintained.
6. The method according to claim 1 , wherein first and second control lines connected to each of the plurality of pixels are formed in the display unit, and each of the plurality of pixels includes a pixel switching element, a latch circuit connected to the pixel switching element, and a switch circuit connected to two output terminals of the latch circuit and the first and second control lines, and
wherein in the common electrode pulse driving, the first or second potential corresponding to a display color after updating is input to the first and second control lines.
7. An electrophoretic display apparatus comprising:
a display unit having a plurality of pixels;
a plurality of pixel electrodes, each of the plurality of pixel electrodes corresponding to one of the plurality of pixels;
a common electrode facing the plurality of pixel electrodes; and
an electrophoretic element disposed between the plurality of pixel electrodes and the common electrode, the electrophoretic element having electrophoretic particles; and
a control unit that controls potentials input to the plurality of pixel electrodes and the common electrode,
the control unit selects one of a pixel electrode pulse driving or a common electrode pulse driving for displaying an image on the display unit,
in the pixel electrode pulse driving:
a pulse periodically alternating between first and second potentials is input to the pixel electrode belonging to the pixel of which a display state is changed,
a constant potential applied to the pixel electrode belonging to the pixel of which a display state is not to be changed is maintained, and
the constant potential is applied to the common electrode,
in the common electrode pulse driving: the first or second potential corresponding to a display color after updating is input to each of the plurality of pixel electrodes, and a pulse periodically alternating between the first and second potentials is input to the common electrode, and
the control unit selects between the pixel electrode pulse driving and the common electrode pulse driving is selected based on a ratio of the pixels that are going to be updated by the selected pulse.
8. The electrophoretic display apparatus according to claim 7 , wherein first and second control lines connected to each of the plurality of pixels are formed in the display unit, and each of the plurality of pixels includes a pixel switching element, a latch circuit connected to the pixel switching element, and a switch circuit connected to two output terminals of the latch circuit and the first and second control lines, and
wherein in the pixel electrode pulse driving of the control unit, a pulse periodically alternating between the first and second potentials is input to the first or second control line connected to the pixel electrode belonging to the pixel of which a display state is changed, and the first or second potential equal to a potential of the common electrode is input to the first or second control line connected to the pixel electrode belonging to the pixel of which a display state is maintained.
9. The electrophoretic display apparatus according to claim 7 , wherein first and second control lines connected to each of the plurality of pixels are formed in the display unit, and each of the plurality of pixels includes a pixel switching element, a latch circuit connected to the pixel switching element, and a switch circuit connected to two output terminals of the latch circuit and the first and second control lines, and
wherein in the common electrode pulse driving of the control unit, the first or second potential corresponding to a display color after updating is input to the first and second control lines.
10. The electrophoretic display apparatus according to claim 7 , further comprising a coordinate input device for executing an input operation using a pointing device, wherein the control unit is operated to display a locus of the pointing device on the display unit using the pixel electrode pulse driving.
11. An electronic device comprising an electrophoretic display apparatus according to claim 7 .
12. A method of driving an electrophoretic display apparatus, the electrophoretic display apparatus including:
a display unit having a plurality of pixels;
a plurality of pixel electrodes, each of the plurality of pixel electrodes corresponding to one of the plurality of pixels;
a common electrode facing the plurality of pixel electrodes; and
an electrophoretic element disposed between the plurality of pixel electrodes and the common electrode, the electrophoretic element having electrophoretic particles,
the method comprising:
selecting one of a pixel electrode pulse driving or a common electrode pulse driving for displaying an image on the display unit based on a ratio of the pixels that are going to be updated by selected pulse;
executing the pixel electrode pulse driving in response to the pixel electrode pulse driving being selected for displaying the image on the display unit, the pixel electrode pulse driving including:
applying a pulse periodically alternating between a first and second potential to the pixel electrode belonging to the pixel of which a display state is changed,
maintaining application of a constant potential applied to the pixel electrode belonging to the pixel of which a display state is not to be changed, and
applying the constant potential to the common electrode, and
wherein the pixel electrode pulse driving is selected when the ratio of the pixels of which display states are updated is 50% or less of all the pixels.