HIGH DYNAMIC RANGE DISPLAY DEVICES

• US 20080174614A1
• Filed: 02/13/2008
• Published: 07/24/2008
• Est. Priority Date: 02/27/2001
• Status: Active Grant

• Current Assignee: Dolby Laboratories Licensing Corporation (Dolby Laboratories Incorporated)
• Original Assignee: Dolby Laboratories Licensing Corporation (Dolby Laboratories Incorporated)
• Inventors: SEETZEN, Helge, WHITEHEAD, Lorne, STUERZLINGER, Wolfgang, WARD, Greg
• Granted Patent: US 7,413,309 B2
• Time in Patent Office: Days
• US Class Current: 345/694
• 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 connected to emit individually-controlled amounts of light onto a second array of pixels, the second array of pixels connected to pass individually-controllable portions of the light; and

,

a controller connected to;

receive an image signal, and, based on the image signal, provide, on-the-fly, a first control signal comprising a low-resolution monochrome approximation of a desired image and a second control signal comprising color and differences between the low-resolution monochrome approximation of the desired image and the desired image;

wherein;

the first control signal is configured to control the pixels of the first array of pixels so as to emit modulated light representative of the low-resolution monochrome approximation of the desired image;

the second control signal is configured to control the pixels of the second array of pixels so as to further modulate the light emitted from the first array of pixels and to cause the emitted light to approach the desired image;

the individually-controlled amounts of light emitted by the first array of pixels are controlled in steps of intensity that are coarser than steps of modulation of the individually-controlled portions of light passed by the second array of pixels;

a pixel size of the first array of pixels is larger than a pixel size of the second array of pixels;

each pixel of the first array of pixels corresponds to and is configured to illuminate a plurality of pixels in the second array of pixels; and

the second array of pixels comprises a Liquid Crystal Display (LCD) screen.

2. The display according to claim 1, wherein at least part of at least one of the first control signal and the second control are pre-processed.

3. A method of displaying an image on a display comprising a first array of pixels which emit light onto a second array of pixels, the method comprising:

controlling the first array of pixels to yield a monochrome pattern of light which approximates a desired image specified by image data on the second array of pixels;

determining a control signal to be applied to pixels of the second array of pixels so as to cause the pattern of light to be modulated in both resolution and color by the second array of pixels such that the pattern of light approaches the desired image; and

,

applying the determined control signal to the second array of pixels coincident with controlling the first array to yield the pattern of light;

performing the steps of controlling, determining, and applying on-the-fly;

wherein;

the first array of pixels are controlled in steps of intensity that are coarser than steps of intensity of modulation by the second array of pixels;

a pixel size of the first array of pixels is larger than a pixel size of the second array of pixels;

each pixel of the first array of pixels corresponds to and is configured to illuminate a plurality of pixels in the second array of pixels; and

the second array of pixels comprises a Liquid Crystal Display (LCD) screen.