Display device having display element of simple matrix type, driving method of the same and simple matrix driver
View Patent ↗A display device includes: a matrix-type display element; a row driver that drives a scan electrode of the display element; and a column driver that drives a data electrode of the display element, in which the column driver includes a matrix driver in a segment mode, the row driver includes a matrix driver being switched between the segment mode and a common mode, and the writing of image data to the display element is performed by: invalidating the output of the row driver and the column driver; setting the row driver to the segment mode; and validating the output of the row driver and the column driver after writing selected line specification data to the row driver and writing image data to the column driver, and then setting the row driver to the common driver.
1. A display device comprising:
a display element of matrix type;
a row driver that drives scan electrodes of the display element; and
a column driver that drives data electrodes of the display element, wherein:
the column driver includes a matrix driver in a segment mode;
the row driver includes a matrix driver capable of being switched between the segment mode and a common mode; and
writing of image data to the display element is performed by:
invalidating outputs of the row driver and the column driver;
setting the row driver to the segment mode; and
validating the outputs of the row driver and the column driver after writing selected line specification data to the row driver and writing image data to the column driver, and then setting the row driver to the common mode,
a time from completion of the invalidation of the outputs of the row driver and the column driver to a start of the operation to set the row driver to the segment mode is 1 μs or more, a time from completion of the change of the row driver to the segment mode to a start of the write of selected line specification data to the row driver and the write of image data to the column driver is 1 μs or more, a time from completion of the write of selected line specification data to the row driver and the write of image data to the column driver to a start of the change of the row driver to the common mode is 2 μs or more, and a time from completion of the change of the row driver to the common mode to a start of the validation of the outputs of the row driver and the column driver is 1 μs or more.
2. The display device according to claim 1 , wherein
a clock to write selected line specification data to the row drive is identical to a clock to write image data to the column driver.
3. The display device according to claim 1 , wherein
the invalidation of the outputs of the row driver and the column driver is performed by applying a control signal to set an output voltage to a predetermined value or less of the matrix driver in the segment mode and the matrix driver capable of being switched between the segment mode and the common mode.
4. The display device according to claim 1 , wherein
the invalidation of the outputs of the row driver and the column driver is performed by setting a voltage of driver output power source terminals of the matrix driver in the segment mode and the matrix driver capable of being switched between the segment mode and the common mode, to a predetermined value or less.
5. The display device according to claim 1 , wherein
the display element includes liquid crystal that forms a cholesteric phase.
6. The display device according to claim 5 , wherein
an initial gradation state is a planar state, a gradation state other than the initial gradation state is a state where the planar state and a focal conic state coexist mixedly, and a value of a halftone is determined by a coexistence ratio.
7. The display device according to claim 6 , wherein:
the display element is brought into a gradation state other than the initial gradation state by applying a gradation voltage pulse to an initialized pixel after applying an initialization voltage pulse to the pixel to bring the pixel into the initial gradation state; and
a cumulative time during which the gradation pulse is applied is related to the value of a gradation state.
8. The display device according to claim 1 , wherein
the display element comprises a laminated structure in which a plurality of display elements that exhibit a plurality of different kinds of reflected light are laminated.
9. A method of driving a display device, the display device comprising a display element of matrix type, a row driver that drives scan electrodes of the display element, and a column driver that drives data electrodes of the display element, wherein the column driver includes a matrix driver in a segment mode and the row driver includes a matrix driver capable of being switched between the segment mode and a common mode, wherein in the method, display data is written to the display element by:
invalidating outputs of the row driver and the column driver;
writing selected line specification data to the row driver and writing image data to the column driver in a state where the row driver is set to the segment mode;
setting the row driver to the common mode; and
validating outputs of the row driver and the column mode, wherein
a time from completion of the invalidation of the outputs of the row driver and the column driver to a start of the operation to set the row driver to the segment mode is 1 μs or more, a time from completion of the change of the row driver to the segment mode to a start of the write of selected line specification data to the row driver and the write of image data to the column driver is 1 μs or more, a time from completion of the write of selected line specification data to the row driver and the write of image data to the column driver to a start of the change of the row driver into the common mode is 2 μs of more, and a time from completion of the change of the row driver to the common mode to a start of the validation of the outputs of the row driver and the column driver is 1 μs or more.
10. The driving method according to claim 9 , wherein
a clock to write selected line specification data to the row drive is identical to a clock to write image data to the column driver.
11. The driving method according to claim 9 , wherein
the invalidation of the output of the row driver and the column driver is performed by applying a control signal to set an output voltage of the matrix driver in the segment mode and the matrix driver capable of being switched between the segment mode and the common mode to, a predetermined value or less.
12. The driving method according to claim 9 , wherein
the invalidation of the outputs of the row driver and the column driver is performed by setting a voltage of a driver output power source terminals of the matrix driver in the segment mode and the matrix driver capable of being switched between the segment mode and the common mode, to a predetermined value or less.
13. The driving method according to claim 9 , wherein
the display element includes liquid crystal that forms a cholesteric phase.
14. The driving method according to claim 13 , wherein
an initial gradation state is a planar state, a gradation state other than the initial gradation state is a state where the planar state and a focal conic state coexist mixedly, and a value of a halftone is determined by a coexistence ratio.
15. The driving method according to claim 14 , wherein
the display element is brought into a gradation state other than the initial gradation state by applying a gradation voltage pulse to an initialized pixel after applying an initialization voltage pulse to the pixel to bring the pixel into the initial gradation state; and
a cumulative time during which the gradation pulse is applied is related to the value of a gradation state.
16. The driving method according to claim 9 , wherein
the display element comprises a laminated structure in which a plurality of display elements that exhibit a plurality of different kinds of reflected light are laminated.