Methods and systems for enhancing display characteristics

• US 20060284822A1
• Filed: 06/15/2005
• Published: 12/21/2006
• Est. Priority Date: 12/02/2004
• Status: Active Grant

• Current Assignee: Sharp Kabushiki Kaisha (Hon Hai Precision Industry Co., Ltd.)
• Original Assignee: Sharp Laboratories of America Incorporated (Hon Hai Precision Industry Co., Ltd.)
• Inventors: Kerofsky, Louis Joseph, Daly, Scott James
• Granted Patent: US 7,800,577 B2
• Time in Patent Office: Days
• US Class Current: 345/102
• CPC Class Codes: G09G 2320/02 Improving the quality of display appearance
• CPC Class Codes: G09G 2320/0646 Modulation of illumination source brightness and image signal correlated to each other
• CPC Class Codes: G09G 2330/021 Power management, e.g. power saving
• CPC Class Codes: G09G 3/3406 Control of illumination source illumination devices structurally associated with liquid crystal cells G02F1/1336
• CPC Class Codes: G09G 3/36 using liquid crystals

Abstract

Embodiments of the present invention comprise systems, methods and devices for increasing the perceived brightness of an image. In some embodiments this increase compensates for a decrease in display light source illumination.

Claims

1. A method for compensating for a display light source illumination reduction, said method comprising:

a) determining a source light illumination reduction level;

b) adjusting the code values of image pixels in inverse proportion to said illumination reduction level to maintain brightness of said pixels.

2. A method as described in claim 1 wherein said display is a light-valve-modulated display and said adjusting increases the light modulated by said light valves.

3. A method as described in claim 1 wherein said adjusting comprises multiplying said code values by a constant gain multiplier.

4. A method as described in claim 1 wherein said adjusting comprises applying a first gain adjustment for a first range of code values and a second gain adjustment for a second range of code values.

5. A method as described in claim 1 wherein said adjusting comprises applying a constant gain multiplier to a first range of code values and applying a roll-off curve to a second range of code values.

6. A method as described in claim 1 wherein said adjusting comprises applying a gain adjustment to a range of code values below an maximum fidelity point (MFP) and applying a roll-off curve to code values above said MFP.

7. A method as described in claim 5 wherein said constant gain multiplier is dependent on at least one of a display gamma, an efficiency factor and a maximum fidelity point (MFP).

8. A method as described in claim 6 wherein said roll-off curve begins at the value of said in adjustment at said MFP and ends at a point that maps the maximum code value to the maximum display level.

9. A method as described in claim 8 wherein said roll-off curve matches the slope of said gain adjustment at said MFP point.

10. A method as described in claim 8 wherein said roll-off curve has a slope of zero at said end point.

11. A method for adjusting an image for increased brightness, said method comprising:

a) adjusting the code values of a first group of image pixels to increase the perceived brightness of said pixels by applying a gain factor function; and

b) adjusting the code values of a second group of image pixels according to a transition function that transitions from said gain factor function to no gain at a maximum value point.

12. A method as described in claim 11 wherein said gain factor function comprises a constant multiplication factor.

13. A method as described in claim 11 wherein said gain factor function is dependent on at least one of a display gamma, an efficiency factor and a maximum fidelity point (MFP).

14. A method as described in claim 11 wherein said transition function matches the value and slope of said gain factor function at a transition point.

15. A method as described in claim 11 wherein said transition function has a slope of zero at said maximum value point.

16. An apparatus for adjusting an image for increased brightness, said apparatus comprising:

a) a first processor for adjusting the code values of a first group of image pixels to increase the perceived brightness of said pixels by applying a gain factor function; and

b) a second processor for adjusting the code values of a second group of image pixels according to a transition function that transitions from said gain factor function to no gain at a maximum value point.

17. An apparatus as described in claim 16 wherein said gain factor function comprises a constant multiplication factor.

18. An apparatus as described in claim 16 wherein said gain factor function is dependent on at least one of a display gamma, an efficiency factor and a maximum fidelity point (MFP).

19. An apparatus as described in claim 16 wherein said transition function has a slope of zero at said maximum value point.

20. An apparatus as described in claim 16 wherein said transition function matches the value and slope of said gain factor function at a transition point.