Apparatus and Method for Modeling the Light Field of a Local-Dimming LED Backlight for an LCD Display

• US 20120274669A1
• Filed: 04/26/2012
• Published: 11/01/2012
• Est. Priority Date: 04/27/2011
• Status: Active Grant

• Current Assignee: STMicroelectronics International N.V. (STMicroelectronics NV)
• Original Assignee: STMicroelectronics Incorporated (STMicroelectronics NV)
• Inventors: Neal, Greg
• Granted Patent: US 8,692,761 B2
• Time in Patent Office: Days
• US Class Current: 345/690
• CPC Class Codes: G09G 2300/023 Display panel composed of stacked panels
• CPC Class Codes: G09G 2320/0285 using tables for spatial correction of display data
• CPC Class Codes: G09G 2320/0646 Modulation of illumination source brightness and image signal correlated to each other
• CPC Class Codes: G09G 2360/16 Calculation or use of calculated indices related to luminance levels in display data
• CPC Class Codes: G09G 3/342 using several illumination sources separately controlled corresponding to different display panel areas, e.g. along one dimension such as lines

Abstract

An apparatus for displaying images. The apparatus comprises: an LCD panel comprising a plurality of pixels for displaying the images; and a backlight comprising a plurality of light sources. Each of the plurality of light sources is associated with one of a plurality of zones and each of the plurality of zones comprises a plurality of grid points. A controller coupled to the LCD panel and the backlight is configured to retrieve contour data associated with each of the plurality of light sources. The contour data is associated with a 3-D contour shape comprising a plurality of facets, each facet associated with at least one of the plurality of grids. The controller is configured to determine a brightness level of at least one pixel in a first grid based on a slope value associated with a first facet associated with the first grid.

Claims

1. An apparatus for displaying images comprising:

an LCD panel comprising a plurality of pixels for displaying the images;

a backlight comprising a plurality of light sources, wherein each of the plurality of light sources is associated with one of a plurality of zones and each of the plurality of zones comprises a plurality of grid points; and

a controller coupled to the LCD panel and the backlight configured to retrieve contour data associated with each of the plurality of light sources, wherein the contour data is associated with a 3-D contour shape comprising a plurality of facets, each facet associated with at least one of the plurality of grids, and wherein the controller is configured to determine a brightness level of at least one pixel in a first grid based on a slope value associated with a first facet associated with the first grid.

2. The apparatus as set forth in claim 1, wherein the controller is configured to determine a brightness level of the least one pixel in the first grid based on a change in the slope value associated with the first facet.

3. The apparatus as set forth in claim 2, wherein the change in the slope value occurs at a vertex point associated with the first facet.

4. The apparatus as set forth in claim 3, wherein the controller retrieves the contour data from a data table comprising a plurality of vertex points, each vertex point associated with one of the plurality of facets

5. The apparatus as set forth in claim 1, wherein the controller is further configured to adjust a lighting level of at least one zone to improve a contrast ratio of a displayed image.

6. The apparatus as set forth in claim 5, wherein the controller adjusts the lighting level of the at least one zone by adjusting a lighting level of at least a first light source.

7. The apparatus as set forth in claim 6, wherein the controller adjusts the lighting level of the at least one zone by independently adjusting lighting levels of at least two light sources.

8. The apparatus as set forth in claim 1, wherein the apparatus is configured as a flat panel television.

9. An integrated circuit for use with an LCD panel and a backlight comprising a plurality of light sources, each of the plurality of light sources associated with one of a plurality of zones and each of the plurality of zones comprising a plurality of grid points, wherein the integrated circuit is configured to retrieve contour data associated with each of the plurality of light sources, wherein the contour data is associated with a 3-D contour shape comprising a plurality of facets, each facet associated with at least one of a plurality of grids, and wherein the integrated circuit is configured to determine a brightness level of at least one pixel in a first grid based on a slope value associated with a first facet associated with the first grid.

10. The integrated circuit as set forth in claim 9, wherein the integrated circuit is configured to determine a brightness level of the least one pixel in the first grid based on a change in the slope value associated with the first facet.

11. The integrated circuit as set forth in claim 10, wherein the change in the slope value occurs at a vertex point associated with the first facet.

12. The integrated circuit as set forth in claim 11, wherein the integrated circuit retrieves the contour data from a data table comprising a plurality of vertex points, each vertex point associated with one of the plurality of facets

13. The integrated circuit as set forth in claim 9, wherein the integrated circuit is further configured to adjust a lighting level of at least one zone to improve a contrast ratio of a displayed image.

14. The integrated circuit as set forth in claim 13, wherein the integrated circuit adjusts the lighting level of the at least one zone by adjusting a lighting level of at least a first light source.

15. The integrated circuit as set forth in claim 14, wherein the integrated circuit adjusts the lighting level of the at least one zone by independently adjusting lighting levels of at least two light sources.

16. For use with an LCD panel, a method for adjusting lighting levels of a backlight of the LCD panel, the backlight comprising a plurality of light sources, each of the plurality of light sources associated with one of a plurality of zones and each of the plurality of zones comprising a plurality of grid points, the method comprising:

retrieving contour data associated with each of the plurality of light sources, wherein the contour data is associated with a 3-D contour shape comprising a plurality of facets, each facet associated with at least one of a plurality of grids; and

determining a brightness level of at least one pixel in a first grid based on a slope value associated with a first facet associated with the first grid.

17. The method as set forth in claim 16, wherein determining comprises determining a brightness level of the least one pixel in the first grid based on a change in the slope value associated with the first facet.

18. The method as set forth in claim 17, wherein the change in the slope value occurs at a vertex point associated with the first facet.

19. The method as set forth in claim 18, wherein retrieving comprises retrieving the contour data from a data table comprising a plurality of vertex points, each vertex point associated with one of the plurality of facets

20. The method as set forth in claim 16, further comprising adjusting a lighting level of at least one zone to improve a contrast ratio of a displayed image.