Liquid crystal display device and driving method of the same
View Patent ↗A liquid crystal display device and driving method therefor are disclosed. The device includes a plurality of signal lines that apply different gray scale voltages to each of the pixels. A driving circuit is provided to generate the gray scale voltages to be applied to the pixels. In operation, the driving circuit applies the first gray scale voltage at intervals of the horizontal scanning time within a display period. The second gray scale voltage is output by a number of times that is not smaller than twice and not greater than (M−N) times at intervals of the horizontal scanning time from the beginning of the vertical retrace interval. The second gray scale voltage is then stopped until completion of the vertical retrace interval.
1. A driving method of a liquid crystal display device having a plurality of pixels, a plurality of signal lines which apply a gray scale voltage to each of the pixels, and a driving circuit which outputs an output signal for changing the gray scale voltage applied to each of the signal lines, the method comprising the steps of:
outputting the output signal from the driving circuit by a number of times not smaller than twice and not greater than (M−N) times from the beginning of a vertical retrace interval continuously, where M represents a value obtained by dividing the vertical retrace interval by a regular horizontal scanning time and rounding up fractions to the nearest whole number, and N represents an integer not smaller than one; and
thereafter stopping the outputting of the output signal from the driving circuit until completion of the vertical retrace interval.
2. A driving method of a liquid crystal display device according to claim 1 , wherein the output signal is outputted by a number of times not smaller than M/2 times and not greater than (M−N) times within the vertical retrace interval.
3. A driving method of a liquid crystal display device according to claim 1 , wherein the output signal is outputted within the vertical retrace interval in synchronism with a regular horizontal synchronizing signal.
4. A driving method of a liquid crystal display device according to claim 1 , wherein the output signal is outputted within the vertical retrace interval in synchronism with an internally generated horizontal synchronizing signal.
5. A driving method of a liquid crystal display device according to claim 1 , wherein a polarity of the gray scale voltage is inverted at least once within the vertical retrace interval.
6. A driving method of a liquid crystal display device according to claim 1 , wherein a gray scale voltage within the vertical retrace interval is a gray scale voltage for displaying white or black.
7. A liquid crystal display device comprising:
a plurality of pixels;
a plurality of signal lines which apply a gray scale voltage to each of the pixels; and
a driving circuit which outputs an output signal for changing the gray scale voltage applied to each of the signal lines,
wherein the driving circuit:
outputs the output signal to each of the signal lines by a number of times not smaller than twice and not greater than (M−N) times at intervals of a horizontal scanning time from the beginning of a vertical retrace interval continuously, and
thereafter stopping the outputting of the output signal from the driving circuit to each of the signal lines until completion of the vertical retrace interval,
where M represents a value obtained by dividing the vertical retrace interval by a regular horizontal scanning time and rounding up fractions to the nearest whole number, and N represents an integer not smaller than one.
8. A liquid crystal display device according to claim 7 , wherein the driving circuit outputs the output signal by a number of times not smaller than M/2 times and not greater than (M−N) times within the vertical retrace interval.
9. A liquid crystal display device according to claim 7 , wherein the driving circuit inverts a polarity of the gray scale voltage to be outputted, at least once within the vertical retrace interval.
10. A liquid crystal display device according to claim 7 , wherein the gray scale voltage within the vertical retrace interval is a gray scale voltage for displaying white or black.
11. A liquid crystal display device comprising:
a plurality of pixels;
a plurality of signal lines which apply a gray scale voltage to each of the pixels;
a driving circuit which outputs the gray scale voltage to a plurality of pixels; and
a display control circuit which outputs a driving signal to the driving circuit,
wherein the display control circuit:
outputs the driving signal by a number of times not smaller than twice and not greater than (M−N) times at intervals of a horizontal scanning time from the beginning of a vertical retrace interval continuously, and
thereafter stops outputting the driving signal from the display control circuit to the driving circuit until completion of the vertical retrace interval, and
wherein M represents a value obtained by dividing the vertical retrace interval by a regular horizontal scanning time and rounding up fractions to the nearest whole number, and N represents an integer not smaller than one.
12. A liquid crystal display device according to claim 11 , wherein the driving signal is output by a number of times not smaller than M/2 times and not greater than (M−N) times within the vertical retrace interval.
13. A liquid crystal display device according to claim 11 , wherein the driving circuit inverts the polarity of the gray scale voltage to be outputted, at least once within the vertical retrace interval.
14. A liquid crystal display device according to claim 11 , wherein the gray scale voltage within the vertical retrace interval is a gray scale voltage for displaying white or black.
15. A liquid crystal display device comprising:
a plurality of pixels;
a plurality of signal lines which apply a gray scale voltage to each of the pixels;
a driving circuit which outputs the gray scale voltage to a plurality of pixels; and
a display control circuit which outputs a driving signal to the driving circuit, wherein the display control circuit:
outputs the driving signal by a number of times not smaller than twice and not greater than (M−N) times at intervals of a horizontal scanning time from the beginning of a vertical retrace interval continuously, and
thereafter stops outputting the driving circuit until completion of the vertical retrace interval, and
wherein M represents a value obtained by adding together the number of lines each having a period scanned entirely and the number of lines each having a period scanned at least partly when scanning is performed with the horizontal scanning time within the vertical retrace interval, and N represents an integer not smaller than one.
16. A liquid crystal display device according to claim 15 , wherein the driving signal is output by a number of times not smaller than M/2 times and not greater than (M−N) times within the vertical retrace interval.
17. A liquid crystal display device according to claim 15 , wherein the driving circuit inverts the polarity of the gray scale voltage to be outputted, at least once within the vertical retrace interval.
18. A liquid crystal display device according to claim 15 , wherein the gray scale voltage within the vertical retrace interval is a gray scale voltage for displaying white or black.
19. A liquid crystal display device comprising:
a plurality of pixel;
a plurality of signal lines which apply a gray scale voltage to each of the pixels;
a driving circuit which outputs the gray scale voltage to a plurality of pixels; and
a display control circuit which outputs a driving signal to the driving circuit, the display control circuit including:
a first circuit which detects a vertical retrace interval on the basis of an externally inputted horizontal synchronizing signal and generates a first to an M-th within-retrace-interval horizontal reference signals within the vertical retrace interval;
a second circuit which generates a horizontal reference signal by masking the (M−N)-th and the following within-retrace-interval horizontal reference signals among the within-retrace-interval horizontal reference signals generated by the first circuit, wherein N represents an integer not smaller than one and (M−N) represents an integer not smaller than two; and
a third circuit which generates a driving signal for driving the driving circuit, within the vertical retrace interval, on the basis of the horizontal reference signal output from the second circuit,
wherein the display control circuit:
outputs the driving signal by a number of times not smaller than twice and not greater than (M−N) times on the basis of the driving signal at intervals of the horizontal scanning time from the beginning of a vertical retrace interval continuously, and
thereafter stops outputting the driving signal from the display control circuit to the driving circuit until completion of the vertical retrace interval.
20. A liquid crystal display device according to claim 19 , wherein the horizontal reference signal outputted from the second circuit within the vertical retrace interval is not smaller than M/2 in number.
21. A liquid crystal display device according to claim 19 , wherein the display control circuit also includes a fourth circuit which generates a within-display-period horizontal reference signal on the basis of an externally inputted display timing signal.
22. A liquid crystal display device comprising:
a plurality of pixels;
a plurality of signal lines which apply gray scale voltage to each of the pixels;
a driving circuit which outputs the first gray scale voltage and the second gray scale voltage to a plurality of pixels; and
a display control circuit which outputs a driving signal to the driving circuit, the display control circuit including:
a first circuit which detects a vertical retrace interval on the basis of an externally inputted display timing signal and generates a first to an M-th within-retrace-interval horizontal reference signals within the vertical retrace interval;
a second circuit which generates a horizontal reference signal by masking the (M−N)-th and the following within-retrace-interval horizontal reference signals among the within-retrace-interval horizontal reference signals generated by the first circuit, wherein N represents an integer not smaller than one and (M−N) represents an integer not smaller than two; and
a third circuit which generates a driving signal for driving the driving circuit, within the vertical retrace interval on the basis of the horizontal reference signal outputted from the second circuit,
wherein the driving control circuit:
outputs the driving signal by a number of times not smaller than twice and not greater than (M−N) times on the basis of the driving signal at intervals of a horizontal scanning time from the beginning of the vertical retrace interval continuously, and
thereafter stops outputting the driving signal from the display control driving circuit to each of the signal lines until the completion of the vertical retrace interval.
23. A liquid crystal display device according to claim 22 , wherein the horizontal reference signal outputted from the second circuit within the vertical retrace interval is not smaller than M/2 in number.
24. A liquid crystal display device according to claim 22 , wherein the display control circuit also includes a fourth circuit which generates a within-display-period horizontal reference signal on the basis of an externally inputted display timing signal.