Image display method and image display device
In an image display method, a backlight is divided into first areas in a first direction. Each of the first areas includes light-emitting regions. A liquid crystal panel is divided into second areas in the first direction. In the method, a first operation to cause light to be emitted from the light-emitting regions at respective intensity in accordance with frame image data is performed sequentially with respect to each of the first areas. Further, a second operation to apply voltages to the pixels at respective levels in accordance with the frame image data is performed sequentially with respect to each of the second areas. A timing at which the first operation with respect to each of the first areas is started is delayed from a timing at which the second operation with respect to a corresponding one of the second areas is started by a predetermined interval.
1. An image display method using an image display device including:
a backlight having a plurality of light-emitting regions arranged in a matrix configuration in a first direction and a second direction, the light-emitting regions being divided into a plurality of first areas in the first direction; and
a liquid crystal panel on the backlight, the liquid crystal panel having a plurality of pixels arranged in a matrix configuration in the first and second directions, the pixels being divided into a plurality of second areas in the first direction, the method comprising:
performing a first operation to cause light to be emitted from the light-emitting regions at respective intensity in accordance with frame image data, sequentially with respect to each of the first areas; and
performing a second operation to apply voltages to the pixels at respective levels in accordance with the frame image data, sequentially with respect to each of the second areas,
wherein a timing at which the first operation with respect to each of the first areas is started is delayed from a timing at which the second operation with respect to a corresponding one of the second areas is started by a predetermined interval,
wherein the second operation with respect to an earliest one of the second areas is started in synchronization with a rising edge of a synchronization signal, and
wherein a timing at which the second operation with respect to a last one of the second areas is started is same as a timing at which the first operation with respect to an earliest one of the first areas is started.
2. The image display method according to claim 1 , further comprising:
generating, based on the synchronization signal, a subdivided synchronization signal having a period less than a period of the synchronization signal,
wherein the first operation with respect to an earliest one of the first areas is started in synchronization with a rising edge of the subdivided synchronization signal.
3. The image display method according to claim 2 , wherein
the first operation with respect to the earliest one of the first areas is terminated in synchronization with a next rising edge of the subdivided synchronization signal, which is immediately subsequent to the rising edge of the subdivided synchronization signal.
4. The image display method according to claim 1 , wherein the predetermined interval is equal to or greater than an amount that is equal to a period of the synchronization signal divided by the number of the first areas.
5. The image display method according to claim 4 , wherein the predetermined interval is less than the period of the synchronization signal.
6. The image display method according to claim 1 , wherein a timing at which the first operation with respect to a next one of the first areas, which is immediately subsequent to the earliest one of the first areas, is started is delayed from a timing at which the first operation with respect to the earliest one of the first areas is started by an amount that is equal to a period of the synchronization signal divided by the number of the first areas.
7. The image display method according to claim 1 , wherein the number of first areas is equal to the number of second areas.
8. The image display method according to claim 1 , wherein the first direction is a vertical direction of display, and the second direction is a horizontal direction of display.
9. An image display device comprising:
a backlight including a plurality of light-emitting regions arranged in a matrix configuration in a first direction and a second direction, the light-emitting regions being divided into a plurality of first areas in the first direction;
a liquid crystal panel on the backlight, the liquid crystal panel including a plurality of pixels arranged in a matrix configuration in the first and second directions, the pixels being divided into a plurality of second areas in the first direction; and
a controller configured to perform:
a first operation to cause light to be emitted from the light-emitting regions at respective intensity in accordance with frame image data, sequentially with respect to each of the first areas, and
a second operation to apply voltages to the pixels at respective levels in accordance with the frame image data, sequentially with respect to each of the second areas,
wherein a timing at which the controller starts the first operation with respect to each of the first areas is delayed from a timing at which the controller starts the second operation with respect to a corresponding one of the second areas by a predetermined interval,
wherein the controller is configured to start the second operation with respect to an earliest one of the second areas in synchronization with a rising edge of a synchronization signal, and
wherein a timing at which the controller starts the second operation with respect to a last one of the second areas is same as a timing at which the controller starts the first operation with respect to an earliest one of the first areas.
10. The image display device according to claim 9 , wherein the controller is configured to generate, based on the synchronization signal, a subdivided synchronization signal having a period less than a period of the synchronization signal, and start the first operation with respect to an earliest one of the first areas in synchronization with a rising edge of the subdivided synchronization signal.
11. The image display device according to claim 10 , wherein the controller terminates the first operation with respect to the earliest one of the first areas in synchronization with a next rising edge of the subdivided synchronization signal, which is immediately subsequent to the rising edge of the subdivided synchronization signal.
12. The image display device according to claim 9 , wherein the predetermined interval is equal to or greater than an amount that is equal to a period of the synchronization signal divided by the number of the first areas.
13. The image display device according to claim 12 , wherein the predetermined interval is less than the period of the synchronization signal.
14. The image display device according to claim 9 , wherein a timing at which the controller starts the first operation with respect to a next one of the first areas, which is immediately subsequent to the earliest one of the first areas, is delayed from a timing at which the controller starts the first operation with respect to the earliest one of the first areas by an amount that is equal to a period of the synchronization signal divided by the number of the first areas.
15. The image display device according to claim 9 , wherein the number of first areas is equal to the number of second areas.
16. The image display device according to claim 9 , wherein the first direction is a vertical direction of display, and the second direction is a horizontal direction of display.