HDR displays having location specific modulation

• US 7,377,652 B2
• Filed: 07/31/2007
• Issued: 05/27/2008
• Est. Priority Date: 02/27/2001
• Status: Expired due to Term

• Current Assignee: Dolby Laboratories Licensing Corporation (Dolby Laboratories Incorporated)
• Original Assignee: Dolby Laboratories Licensing Corporation (Dolby Laboratories Incorporated)
• Inventors: Whitehead, Lorne A, WARD, Gregory John, Stuerzlinger, Wolfgang, Seetzen, Helge
• Primary Examiner(s): KOVAL, MELISSA J
• Application Number:
  US11/831,737
• Publication Number:
  US 20070268577A1
• Time in Patent Office: 301 Days
• Field of Search: 353/30, 353/31, 353/69, 353/70, 353/121, 353/122, 353/84, 353/94, 353/99, 348/742, 348/743, 348/744, 348/383, 348/511, 382/174, 345/1.1, 359/443, 359452-456, 359/460, 349/5, 349/7, 349/8, 349/112, 349/113
• US Class Current: 353/30
• CPC Class Codes: G02F 1/133504 Diffusing, scattering, diffracting elements associated to illuminating devices G02F1/133606
• CPC Class Codes: G02F 1/133526 Lenses, e.g. microlenses or Fresnel lenses
• CPC Class Codes: G02F 1/133553 Reflecting elements associated to illuminating devices G02F1/133605
• CPC Class Codes: G02F 1/1347 Arrangement of liquid crystal layers or cells in which the final condition of one light beam is achieved by the addition of the effects of two or more layers or cells
• CPC Class Codes: G03B 21/14 Details
• CPC Class Codes: G03B 21/2053 Intensity control of illuminating light controlled by video signal processing H04N5/74 or H04N9/31
• CPC Class Codes: G03B 21/26 Projecting separately subsidiary matter simultaneously with main image
• CPC Class Codes: G03B 21/56 Projection screens
• CPC Class Codes: G03B 21/567 for colour projection G03B21/58, G03B21/60 take precedence
• CPC Class Codes: G03B 21/60 characterised by the nature of the surface
• CPC Class Codes: G03B 21/625 Lenticular translucent screens
• CPC Class Codes: G09G 2300/023 Display panel composed of stacked panels
• CPC Class Codes: G09G 2310/024 Scrolling of light from the illumination source over the display in combination with the scanning of the display screen
• CPC Class Codes: G09G 2320/0233 Improving the luminance or brightness uniformity across the screen
• 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 2320/0633 by amplitude modulation of the brightness of the illumination source
• CPC Class Codes: G09G 2320/064 by time modulation of the brightness of the illumination source
• CPC Class Codes: G09G 3/001 using specific devices not provided for in groups G09G3/02 - G09G3/36, e.g. using an intermediate record carrier such as a film slide; Projection systems; Display of non-alphanumerical information, solely or in combination with alphanumerical information, e.g. digital display on projected diapositive as background slide projectors per se G03B23/00 = 42 HP
• CPC Class Codes: G09G 3/3426 the different display panel areas being distributed in two dimensions, e.g. matrix
• CPC Class Codes: G09G 5/10 Intensity circuits
• CPC Class Codes: H04N 5/7416 : involving the use of a spatial light modulator, e.g. a light valve, controlled by a video signal
• CPC Class Codes: H04N 9/31 : Projection devices for colour picture display , e.g. using electronic spatial light modulators [ESLM]
• CPC Class Codes: H04N 9/3126 : for spatial light modulators in series
• CPC Class Codes: H04N 9/3138 : using arrays of modulated light sources electroluminescent display devices G09G3/30
• CPC Class Codes: H04N 9/3188 : Scale or resolution adjustment scaling in general G06T3/40; resolution modifying circuits for displays in general G09G5/391

Abstract

A display has a screen which incorporates a light modulator. The screen may be a front projection screen or a rear-projection screen. Elements of the light modulator may be controlled to adjust the intensity of light emanating from corresponding areas on the screen. The display may provide a high dynamic range.

Claims

1. A display comprising:

a first array of pixels configured to project individually-selectable amounts of light onto a second array of pixels;

the second array of pixels configured to transmit individually-selectable amounts of light; and

,

a controller connected to the first and second arrays, the controller configured to drive the first array to project an approximation of an image specified by image data onto the second array, and to drive the second array to modulate the approximation of the image according to differences between characteristics of light incident on each individual pixel of the second array and desired characteristics of light specified by image data for a location of the image which corresponds to that individual pixel of the second array;

wherein each pixel of the first array is configured to project light onto the second array in a manner characterized by a spread function having a full width at half-maximum in the range of 0.3×

d₂ to 3×

d₂, where d₂ is a center-to-center inter-pixel spacing of pixels of the first array.

2. A display according to claim 1 wherein each pixel of the first array projects light onto a plurality of pixels of the second array, and light from a plurality of pixels of the first array is incident on each pixel of the second array.

3. A display according to claim 1 wherein a number of pixels of the first array is less than a number of pixels of the second array.

4. A display according to claim 1 wherein the controller is configured to:

drive each controllable element of the first array of pixels to project light having a brightness level selected from a number N of discrete brightness levels; and

drive each controllable element of the second array of pixels to have a transmissivity level selected from a number M of discrete transmissivity levels, wherein N is greater than M.

5. A display according to claim 1 wherein the controller is configured to:

drive each controllable element of the first array of pixels to project light having a brightness level selected from a number N of discrete brightness levels; and

drive each controllable element of the second array of pixels to have a transmissivity level selected from a number M of discrete transmissivity levels, wherein N is less than M.

6. A display according to claim 1 comprising a diffuser located on a side of the second array which faces away from the first array.

7. A display according to claim 1 comprising an optical system positioned between the first array and the second array for imaging the light projected from the first array onto the second array.

8. The display according to claim 1, wherein the controller is further configured to drive the first array with a local dimming signal produced from an image signal and configured to dim selected pixels of the first array.

9. The display according to claim 1, further comprising a diffuser between the first and second arrays.

10. The display according to claim 1, wherein the controller is configured to adjust the pixels of the second array of pixels based on local dimming to be performed by the first array of pixels.

11. The display according to claim 1, wherein the controller is configured to drive the arrays via control signals generated on-the-fly.

12. The display according to claim 1, wherein the controller is configured to drive the arrays via control signals generated based on a pre-processing of image data and a final processing.

13. The display according to claim 1, wherein the controller is configured to drive the arrays via control signals generated in stages, including pre-processing and final processing stages.

14. The display according to claim 1, wherein the first array of pixels is of a higher resolution than the second array of pixels.

15. The display according to claim 1, wherein at least one of the arrays comprises a plurality of colored sub-pixels.

16. The display according to claim 1, wherein:

one of the arrays comprises a plurality of colored sub-pixels;

one of the arrays has a higher resolution than the other array;

the array having the higher resolution is the same array that comprises the colored sub-pixels; and

the other array comprises a monochrome pixel array.

17. The display according to claim 1, wherein:

one of the pixel arrays comprises a monochrome pixel array;

the other pixel array comprises a color pixel array comprising colored sub-pixels; and

the color pixel array comprises a Liquid Crystal Display (LCD) screen.

18. The display according to claim 1, wherein the pixel arrays have different resolutions, the first pixel array being of a comparatively lower resolution and the second pixel array being of a comparatively higher resolution, and each pixel of the lower-resolution pixel array is common to a plurality of pixels in the higher-resolution pixel array.

19. The display according to claim 18, wherein the controller is configured to drive the arrays via control signals that comprise an adjustment in values for the higher-resolution pixel array to reduce artifacts which result from each pixel of the lower-resolution pixel array being common to a plurality of pixels in the higher-resolution pixel array.

20. The display according to claim 1, wherein:

the first pixel array comprising a monochrome pixel array;

the second pixel array comprising a Liquid Crystal Display (LCD) color pixel array having a plurality of colored sub-pixels having a resolution that is comparatively higher than the monochrome pixel array;

each pixel of the lower-resolution pixel array is common to a plurality of pixels in the higher-resolution pixel array; and

the controller is configured to drive the arrays via control signals that comprise an adjustment in values for the higher-resolution array to reduce artifacts which result from each pixel of the lower-resolution pixel array being common to a plurality of pixels in the higher-resolution pixel array.

21. The display according to claim 1, wherein the display is a Liquid Crystal Display (LCD) display.

22. The display according to claim 1, wherein:

the controller is further configured to,

drive the first array with a first control signal comprising a local dimming signal produced from an image signal and configured to dim selected pixels of the first array,

adjust the pixels of the second array of pixels with a second control signal based on local dimming to be performed by the first array of pixels, and

generate the control signals in stages and on-the-fly, wherein the stages include pre-processing and final processing stages;

the display device further comprising a diffuser between the first and second arrays;

one of the pixel arrays comprises a color pixel array having a plurality of colored sub-pixels;

the pixel arrays having different resolutions, the color pixel array having a comparatively higher resolution than the other pixel array which has a comparatively lower resolution, and each pixel of the lower-resolution pixel array is common to a plurality of pixels in the higher-resolution pixel array;

the lower-resolution pixel array comprises a monochrome pixel array; and

the higher-resolution color pixel array comprises a Liquid Crystal Display (LCD) screen.

23. The display according to claim 22, wherein the control signals include a value of each pixel of the lower-resolution pixel array.

24. The display according to claim 22, wherein the control signals comprise an adjustment in values for the higher-resolution pixel array to reduce artifacts which result from each pixel of the lower-resolution pixel array being common to a plurality of pixels in the higher-resolution pixel array.

25. The display according to claim 22, wherein the control signals comprise an adjustment in values for the higher-resolution pixel array to reduce artifacts which result from each pixel of the lower-resolution pixel array being common to a plurality of pixels in the Liquid Crystal Display (LCD).