Backlight unit and liquid crystal display having the same
View Patent ↗A liquid crystal display includes a liquid crystal panel that displays an image signal, a backlight unit supplying light to the liquid crystal panel, and a backlight control circuit to scan the backlight unit. The backlight control circuit supplies a pulse width modulation signal to rows of the backlight unit, which are adjacent to rows being scanned, such that the rows adjacent to the rows being scanned have a brightness lower than a brightness of the rows being scanned.
1. A liquid crystal display comprising:
a liquid crystal panel that displays an image signal;
a backlight unit that supplies a light to the liquid crystal panel; and
a backlight control circuit that controls a brightness of the backlight unit,
wherein the backlight control circuit comprises a scanning control circuit scanning the backlight unit in a row direction by supplying a first pulse width modulation signal to the backlight unit, and scanning rows of the backlight unit adjacent to the scanned rows by supplying a second pulse width modulation signal to the rows adjacent to the scanned rows such that the rows adjacent to the scanned rows have a brightness lower than a brightness of the scanned rows,
wherein the scanning control circuit performs a pre-scanning by supplying the second pulse width modulation signal to rows to be scanned in a next scanning timing, and performs a post-scanning by supplying the second pulse width modulation signal to the rows that have been scanned in a previous scanning timing.
2. The liquid crystal display of claim 1 , wherein, if a row to be scanned is a first row of the backlight unit, the pre-scanning is not performed.
3. The liquid crystal display of claim 1 , wherein the second pulse width modulation signal has a brightness level lower than a brightness level of the first pulse width modulation signal.
4. The liquid crystal display of claim 3 , wherein the rows receiving the second pulse width modulation signal have a brightness corresponding to 1/n of a brightness of the rows being scanned.
5. The liquid crystal display of claim 1 , wherein the scanning control circuit does not perform post-scanning if the scanned row is a last row of the backlight unit.
6. The liquid crystal display of claim 1 , wherein the second pulse width modulation signal has a brightness level lower than a brightness level of the first pulse width modulation signal.
7. The liquid crystal display of claim 6 , wherein the rows receiving the second pulse width modulation signal have a brightness corresponding to 1/n of brightness of the scanned rows.
8. A backlight unit comprising:
a backlight unit that supplies a light to a liquid crystal panel; and
a backlight control circuit that controls a brightness of the backlight unit,
wherein the backlight control circuit comprises a scanning control circuit scanning the backlight unit in a row direction by supplying a first pulse width modulation signal to the backlight unit, and scanning rows of the backlight unit adjacent to the scanned rows by supplying a second pulse width modulation signal to the rows adjacent to the scanned rows such that the rows adjacent to the scanned rows have a brightness lower than a brightness of the scanned rows,
wherein the scanning control circuit performs a pre-scanning by supplying the second pulse width modulation signal to rows to be scanned in a next scanning timing, and performs a post-scanning by supplying the second pulse width modulation signal to rows that have been scanned in a previous scanning timing.
9. The backlight unit of claim 8 , wherein the second pulse width modulation signal has a brightness level lower than a brightness level of the first pulse width modulation signal.
10. The backlight unit of claim 8 , wherein the second pulse width modulation signal has a brightness level lower than a brightness level of the first pulse width modulation signal.
11. A backlight unit comprising:
a backlight unit that supplies a light to a liquid crystal panel; and
a backlight control circuit that controls a brightness of the backlight unit,
wherein the backlight control circuit comprises a scanning control circuit scanning the backlight unit in a row direction by supplying a first pulse width modulation signal to the backlight unit, and performing a pre-scanning by supplying a second pulse width modulation signal to rows to be scanned in a next scanning timing, and performing a post-scanning by supplying the second pulse width modulation signal to rows that have been scanned in a previous scanning timing.
12. The backlight unit of claim 11 , wherein the second pulse width modulation signal has a brightness level lower than a brightness level of the first pulse width modulation signal.
13. The backlight unit of claim 12 , wherein the rows receiving the second pulse width modulation signal have a brightness corresponding to 1/n of a brightness of the rows being scanned.
14. The backlight unit of claim 11 , wherein, if a row to be scanned is a first row of the backlight unit, the pre-scanning is not performed.
15. The backlight unit of claim 11 , wherein the scanning control circuit does not perform post-scanning if the scanned row is a last row of the backlight unit.