DISPLAY DEVICE

• US 20100265405A1
• Filed: 04/13/2010
• Published: 10/21/2010
• Est. Priority Date: 04/17/2009
• Status: Active Grant

• Current Assignee: Panasonic Intellectual Property Corporation of America (Panasonic Holdings Corporation)
• Original Assignee: Japan Display Incorporated
• Inventors: Ono, Kikuo, Maruyama, Junichi, Toshima, Goki, Hosogi, Koji, Owa, Misa
• Granted Patent: US 8,531,383 B2
• Time in Patent Office: Days
• US Class Current: 348/687
• CPC Class Codes: G09G 2320/0247 Flicker reduction other than flicker reduction circuits used for single beam cathode-ray tubes
• CPC Class Codes: G09G 2320/0261 in the context of movement of objects on the screen or movement of the observer relative to the screen
• CPC Class Codes: G09G 2320/062 Adjustment of illumination source parameters
• CPC Class Codes: G09G 3/3426 the different display panel areas being distributed in two dimensions, e.g. matrix

Abstract

Provided is a display device capable of producing an image of excellent quality with reduced flicker and little reduction in luminance, the display device including: a backlight having light sources such as LED devices arranged two-dimensionally, each of which may be individually modulated in luminance; a moving velocity detection unit VD1 (109) for detecting a moving velocity of an object in a video (for example, moving velocity of a foreground); and a luminance variation control unit (113) for automatically controlling luminance variations of the LED devices for each frame, in accordance with the moving velocity.

Claims

1. A display device for receiving input data of a video and displaying the video, comprising:

a display panel having a plurality of pixels arranged therein for displaying the video;

a backlight for irradiating the display panel, the backlight including a plurality of light sources and being controllable in luminance for each of the plurality of light sources;

a moving velocity detection unit for detecting a moving velocity of an object in the video; and

a luminance variation control unit for controlling, for each of the plurality of light sources, a luminance variation of the light source in accordance with the moving velocity detected by the moving velocity detection unit.

2. The display device according to claim 1, wherein the luminance variation control unit sets the luminance variation to a first value in a case where the moving velocity of the object in the video is high, and sets the luminance variation to a second value in a case where the moving velocity of the object in the video is low.

3. The display device according to claim 2, wherein the first value is larger than the second value.

4. The display device according to claim 3, further comprising a register capable of externally adjusting the first value and the second value.

5. The display device according to claim 4, wherein the second value is adjustable in smaller units as compared with the first value.

6. The display device according to claim 1, further comprising an adjacent area irradiation computing unit for computing a luminance of a light source of at least one or all areas adjacent in upward, downward, rightward, leftward, and diagonal directions to a display area for displaying the object in the video, so that the at least one or all adjacent areas are irradiated in advance,

wherein the luminance variation control unit controls, as well as controlling the luminance variation of the light source in the display area in accordance with the moving velocity detected by the moving velocity detection unit, the luminances of the light sources in the adjacent areas in accordance with the luminance computed by the adjacent area irradiation computing unit.

7. The display device according to claim 6, further comprising an object moving direction detection unit for detecting a moving direction of the object in the video,

wherein the adjacent area irradiation computing unit computes a luminance of a light source in an adjacent area that is a move destination of the object in the video, so that the adjacent area is irradiated in advance.

8. A display device for receiving input data of a video and displaying the video, comprising:

a display panel having a plurality of pixels arranged therein for displaying the video;

a backlight for irradiating the display panel, the backlight including a plurality of light sources and being controllable in luminance for each of the plurality of light sources;

an adjacent area irradiation computing unit for computing a luminance of a light source of at least one or all areas adjacent in upward, downward, rightward, leftward, and diagonal directions to a display area for displaying an object in the video, so that the at least one or all adjacent areas are irradiated in advance,

a comparison unit for comparing a light emission luminance value of a previous frame with a light emission luminance of a display frame; and

a luminance variation control unit for controlling, as well as controlling a luminance variation of the light source in the display area in accordance with a result of the comparison obtained by the comparison unit, the luminance of the light source in the at least one or all adjacent areas in accordance with the luminance computed by the adjacent area irradiation computing unit.

9. The display device according to claim 8, further comprising an external register capable of changing a range of the at least one or all adjacent areas to be irradiated.

10. The display device according to claim 8, further comprising an external register capable of changing a lighting luminance of the light source of the adjacent area to be irradiated.

11. The display device according to claim 8, wherein:

the comparison unit calculates one of a difference and a mean squared error between the light emission luminance value of the previous frame and the light emission luminance value of the display frame, sets the luminance variation to a third value in a case where the one of the difference and the mean squared error is large, and sets the luminance variation to a fourth value in a case where the one of the difference and the mean squared error is small.

12. The display device according to claim 11, wherein the third value is larger than the fourth value.

13. The display device according to claim 11, further comprising a register capable of externally adjusting the third value and the fourth value.

14. The display device according to claim 13, wherein the fourth value is adjustable in smaller units as compared with the third value.