Field sequential light source modulation for a digital display system

• US 7,364,306 B2
• Filed: 12/05/2005
• Issued: 04/29/2008
• Est. Priority Date: 06/20/2005
• Status: Active Grant

• Current Assignee: Samsung Electronics Co. Ltd.
• Original Assignee: Digital Display Innovations, LLC
• Inventors: Margulis, Neal D.
• Primary Examiner(s): KOVAL, MELISSA J
• Application Number:
  US11/294,173
• Publication Number:
  US 20070035707A1
• Time in Patent Office: 876 Days
• Field of Search: 353/30, 353/31, 353/84, 353/94, 353/121, 353/85, 353/99, 353/122, 348742-745, 348/771, 348/806, 345/102, 345/103, 345/88, 345/690
• US Class Current: 353/31
• CPC Class Codes: G03B 21/005 Projectors using an electronic spatial light modulator but not peculiar thereto
• CPC Class Codes: G03B 21/2033 LED or laser light sources
• CPC Class Codes: G03B 21/206 Control of light source other than position or intensity
• CPC Class Codes: G03B 21/26 Projecting separately subsidiary matter simultaneously with main image
• CPC Class Codes: G09G 2310/0235 Field-sequential colour display
• 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 2320/041 Temperature compensation
• CPC Class Codes: G09G 2320/045 Compensation of drifts in the characteristics of light emitting or modulating elements
• CPC Class Codes: G09G 2320/0666 for control of colour parameters, e.g. colour temperature
• CPC Class Codes: G09G 2360/144 the light being ambient light
• CPC Class Codes: G09G 2360/145 the light originating from the display screen
• CPC Class Codes: G09G 3/03 specially adapted for displays having non-planar surfaces, e.g. curved displays
• CPC Class Codes: G09G 3/3413 Details of control of colour illumination sources
• 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
• 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 9/312 Driving therefor driving of electronic spatial light modulators in displays other than projection devices G09G3/34, G09G3/36; control of liquid crystal elements G02F1/133; control of micromechanical modulators G02B26/08
• CPC Class Codes: H04N 9/3155 for controlling the light source light source control per se H05B35/00 – H05B47/00; control of an illumination source for displays in general G09G3/3406

Abstract

A digital display system consists of an image modulator and multiple light modulators. An image processing system processes an incoming data stream, scans processed data to an image modulator and controls for the light modulators. Other user inputs and sensors are used to affect the processing and controls. The timing for scanning the processed data into the image modulators is controlled along with the intensity and wavelength of the light modulators. The display system may implement a spatial and temporal image processing, digital shutter controls, rolling shutter controls, sequential color output, adaptive dynamic sensor feedback, frame rate matching, motion compensated field sequencing and a variety of other techniques to produce a high quality display output. The resulting display has improved image consistency, enhanced color gamut, higher dynamic range and is better able to portray high motion content.

Claims

1. A display comprising:

multiple light sources at multiple locations of said display;

light source controls to dynamically vary the brightness of said light sources;

an image modulator including an array of individually controllable pixels into which pixel values are scanned during an image modulator scanning time;

one or more controllers receiving a spatially processed data stream of values based on which said controllers control the values for

said individually controllable pixels, and

said light sources at multiple locations to vary their brightness; and

wherein said values for said light sources at one or more locations are set to zero during some portion of said image modulator scanning time.

2. The display of claim 1 further comprising an adaptive and dynamic means responsive to sensor feedback to compensate the brightness for one or more of said light sources.

3. The display of claim 1 further comprising means responsive to said processed data stream to vary the color of said one or more light sources by controlling the brightness for three or more different wavelength LEDs.

4. The display of claim 1 further comprising means responsive to sensor feedback to vary the color of said one or more light sources by controlling the brightness for three or more different wavelength LEDs.

5. The display of claim 1 wherein said multiple light sources are positioned in two or more parallel bands and said light sources'"'"' values are set to zero during a portion of said image modulator scanning time.

6. The display of claim 1 wherein image modulator scanning times are spaced by a period of time based on a multiple of the frame rate of said processed data stream.

7. The display of claim 3 wherein said processed data stream includes frames and said frames are decomposed into temporal fields that are sequentially scanned and displayed by said image modulator, and wherein said brightness is varied for the display of said sequential fields.

8. The display of claim 1 wherein said plurality of light sources illuminate a microdisplay of a projection display system and further comprising a multiple lenslets lens system such that the illumination paths of said light sources correspond to a proximity of said microdisplay modulator pixels.

9. A display comprising:

three or more light sources at different locations of said display, including

a plurality of light sources of different respective wavelengths, and

an equal plurality of light source controls to dynamically vary the brightness of each different wavelength light source as a function of the location in said display;

an image modulator including an array of individually controllable pixels which, during an image modulator scanning time, is scanned with a field of data which makes up part of a frame; and

a controller receiving a processed data stream of values for incoming frames based on which said controller

controls the values for said individually controllable pixels,

controls said light sources to vary the brightness for said different wavelengths at multiple locations of said display, and

sequences two or more of said fields of data for each incoming frame.

10. The display of claim 9 further comprising an adaptive and dynamic means responsive to sensor feedback to compensate the light intensity output for one or more of said light sources.

11. The display of claim 9 further comprising means responsive to sensor feedback to vary the color of said one or more light sources by controlling the brightness for multiple different wavelength LEDs.

12. The display of claim 9 wherein the brightness of said light sources are set to zero for some time during each said image modulator scanning time.

13. The display of claim 9 wherein the brightnesses of said light sources are adjusted one or more times during the time of sequencing each of said fields.

14. The display of claim 9 wherein said image modulator scanning times are spaced by a period of time that is varied based on the frame rate of said processed data stream.

15. The display of claim 9 wherein said plurality of light sources illuminate a projection display system and further comprising a multiple lenslets lens system such that said light sources generally correspond to a proximate group of said image modulator pixels.

16. The display of claim 9 wherein the incoming frame rate is used to proportionally match the sequencing time for said display fields so that the outgoing frame rate is an integer multiple of the incoming frame rate.

17. The display of claim 9 wherein said image modulator scanning times are spaced by a period of time that is varied based on the motion of one or more objects within said processed data stream.

18. A method for displaying an image having high image quality, high color gamut and high dynamic range, and achieving high quality motion portrayal, comprising:

processing a real time display data stream from fill frames each including a certain number of pixels into sequential fields each of which may include different colors in different areas;

spatial processing the sequential fields;

using the spatial-processed sequential fields to separately modulate the brightnesses of one or more light sources corresponding to a group of image modulator pixels wherein each said group has fewer than said certain number of pixels and light sources corresponding to different groups may have different colors; and

using the spatial-processed sequential fields to modulate individual pixels to form said image.

19. The method of claim 18 wherein said sequential fields are frame rate matched to be an integer multiple of the frame rate inherent in said real time display data stream.

20. The method of claim 18 wherein using said sequential fields to modulate one or more light sources is synchronized with using said sequential fields to modulate pixels so that the display does not show the image pixel modulation during the field transitions from scanning of said sequential fields.

21. A field sequencing display comprising:

a plurality of light sources, each including at least 3 LEDs of different colors, at different locations of said display;

an image modulator, including individually controllable pixels, into which pixel values are scanned during each one of multiple field intervals of an image frame period; and

a controller, for receiving a processed data stream of values for incoming image frames and, in response to received values, for

controlling said light sources to vary the brightness of said LEDs as a function of their locations in said display during each said field interval; and

controlling the light transmissions of said individually controllable pixels during each said field interval.

22. A field sequencing display comprising:

a plurality of light sources, each including at least 3 LEDs of different colors, at different locations of said display;

an image modulator, including individually controllable pixels, into which pixel values are scanned during each one of multiple field intervals of an image frame period; and

a controller, for receiving a processed data stream of values for incoming image frames and, in response to received values, for

controlling said light sources so that at least 2 LEDs of different colors produce light during each said field interval; and

controlling the light transmissions of said individually controllable pixels during each said field interval.

23. A field sequencing display comprising:

a plurality of light sources, each including at least 3 LEDs of different colors, at different locations of said display;

an image modulator, including individually controllable pixels, into which pixel values are scanned during each one of multiple field intervals of an image frame period; and

a controller, for receiving a processed data stream of values for incoming image frames and, in response to received values, for

controlling said light sources to vary the brightness of said different colors during each said field interval; and

controlling the light transmissions of said individually controllable pixels during each said field interval; and

wherein said field intervals may have different durations.

24. A field sequencing display comprising:

a plurality of light sources, each including at least 3 LEDs of different colors, at different locations of said display;

an image modulator, including individually controllable pixels, into which pixel values are scanned during each one of multiple field intervals of an image frame period;

a controller, for receiving a processed data stream of values for incoming image frames and, in response to received values, for

controlling said light sources to vary the brightness of said different colors during each said field interval; and

controlling the light transmissions of said individually controllable pixels during each said field interval; and

means responsive to sensor feedback to dynamically vary the light output of at least one of said light sources.