Backlit display with improved dynamic range

• US 20070159450A1
• Filed: 03/08/2007
• Published: 07/12/2007
• Est. Priority Date: 11/09/2001
• Status: Active Grant

• Current Assignee: Sharp Kabushiki Kaisha (Hon Hai Precision Industry Co., Ltd.)
• Original Assignee: Sharp Kabushiki Kaisha (Hon Hai Precision Industry Co., Ltd.)
• Inventors: Daly, Scott
• Granted Patent: US 7,499,017 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 2320/0238 Improving the black level
• CPC Class Codes: G09G 2320/0271 Adjustment of the gradation levels within the range of the gradation scale, e.g. by redistribution or clipping
• 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 2320/066 for control of contrast
• CPC Class Codes: G09G 2360/16 Calculation or use of calculated indices related to luminance levels in display data
• CPC Class Codes: G09G 3/3426 the different display panel areas being distributed in two dimensions, e.g. matrix

Abstract

A display is backlit by a source having spatially modulated luminance to attenuate illumination of dark areas of images and increase the dynamic range of the display.

Claims

1-22. -22. (canceled)

23. A backlit display, comprising:

a backlight to output light at a controllable luminance level; and

a light valve to control, per pixel, transmittance of light from said backlight to create an image, said backlight comprising a plurality of light sources that are independently controllable, the light sources respectively corresponding to areas that constitute part of said image wherein, if a size of a relatively dark area of said image to be displayed in each of said areas is smaller than a predetermined value, said luminance of said light source corresponding to the each of said areas is increased.

26. The backlit display as set forth in claim 23, wherein:

said backlight is usable to output light at a spatially modulatable luminance.

27. The backlit display as set forth in claim 23, wherein in accordance with a first feature regarding brightness of said image to be displayed in each of said areas, luminance of said light source corresponding to the each of said areas is controlled.

24. A backlit display, comprising:

a backlight to output light at a controllable luminance level; and

a light valve to control, per pixel, transmittance of light from said backlight to create an image,

said backlight comprising a plurality of light sources that are independently controllable, the light sources respectively corresponding to areas that constitute part of said image wherein,

if a dark area of said image to be displayed in each of said areas includes a relatively small bright component, said luminance of said light source corresponding to the each of said areas is increased.

28. The backlit display as set forth in claim 24, wherein:

said backlight is usable to output light at a spatially modulatable luminance.

29. The backlit display as set forth in claim 24, wherein

said backlight comprises a plurality of light sources that are independently controllable, the light sources being respectively provided in said areas that constitute part of said image.

25. A backlit display, comprising:

a backlight to output light at a controllable luminance level; and

a light valve to control, per pixel, transmittance of light from said backlight to create an image, in accordance with a first feature regarding brightness of said image to be displayed in each of said areas, luminance of said light source corresponding to the each of said areas is controllable, and wherein if a maximum luminance of said image to be displayed in each of said areas exceeds a threshold, said luminance of said light source corresponding to the each of said areas is increased.

30. The backlit display as set forth in claim 25, wherein:

said backlight is usable to output light at a spatially modulatable luminance.

31. The backlit display as set forth in claim 25, wherein

said backlight comprises a plurality of light sources that are independently controllable, the light sources being respectively provided in said areas that constitute part of said image.

32. A backlit display, comprising:

a backlight to output light at a controllable luminance level; and

a light valve to control, per pixel, transmittance of light from said backlight to create an image, said backlight comprising a plurality of light sources that are independently controllable, the light sources respectively corresponding to areas that constitute part of said image wherein, if a size of a relatively dark area of said image to be displayed in each of said areas is smaller than a predetermined value, said luminance of said light source is controlled so that the human vision system is able to detect details in said relatively dark areas.

35. The backlit display as set forth in claim 32, wherein:

said backlight is usable to output light at a spatially modulatable luminance.

36. The backlit display as set forth in claim 32, wherein in accordance with a first feature regarding brightness of said image to be displayed in each of said areas, luminance of said light source corresponding to the each of said areas is controlled.

33. A backlit display, comprising:

a backlight to output light at a controllable luminance level; and

a light valve to control, per pixel, transmittance of light from said backlight to create an image,

said backlight comprising a plurality of light sources that are independently controllable, the light sources respectively corresponding to areas that constitute part of said image wherein,

if a dark area of said image to be displayed in each of said areas includes a relatively small bright component, said luminance of said light source is controlled so that the human vision system is able to detect details in said relatively dark areas.

37. The backlit display as set forth in claim 33, wherein:

said backlight is usable to output light at a spatially modulatable luminance.

38. The backlit display as set forth in claim 33, wherein

said backlight comprises a plurality of light sources that are independently controllable, the light sources being respectively provided in said areas that constitute part of said image.

34. A backlit display, comprising:

a backlight to output light at a controllable luminance level; and

a light valve to control, per pixel, transmittance of light from said backlight to create an image, in accordance with a first feature regarding brightness of said image to be displayed in each of said areas, luminance of said light source corresponding to the each of said areas is controllable, and wherein if a maximum luminance of said image to be displayed in each of said areas exceeds a threshold, said luminance of said light source is controlled so that the human vision system is able to detect details in said relatively dark areas.

39. The backlit display as set forth in claim 34, wherein:

said backlight is usable to output light at a spatially modulatable luminance.

40. The backlit display as set forth in claim 34, wherein

said backlight comprises a plurality of light sources that are independently controllable, the light sources being respectively provided in said areas that constitute part of said image.