Synchronizing dynamic backlight adaptation

• US 8,629,830 B2
• Filed: 06/24/2008
• Issued: 01/14/2014
• Est. Priority Date: 06/26/2007
• Status: Active Grant

• Current Assignee: Apple Inc.
• Original Assignee: Apple Inc.
• Inventors: Barnhoefer, Ulrich T., Yao, Wei H., Chen, Wei, Corlett, Barry J.
• Primary Examiner(s): SHERMAN, STEPHEN G
• Application Number:
  US12/145,396
• Publication Number:
  US 20090002404A1
• Time in Patent Office: 2,030 Days
• Field of Search: 345/89, 345/102, 345/690, 345/211, 345/698, 345/87, 345/204, 348699-700, 348/687, 348/571, 348/556, 348/672, 382/168, 396/282, 362/600, 349/61
• US Class Current: 345/102
• CPC Class Codes: G09G 2310/0232 Special driving of display border areas
• CPC Class Codes: G09G 2320/0247 Flicker reduction other than flicker reduction circuits used for single beam cathode-ray tubes
• 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 2320/0606 Manual adjustment
• CPC Class Codes: G09G 2320/0626 for control of overall brightness
• CPC Class Codes: G09G 2320/0646 Modulation of illumination source brightness and image signal correlated to each other
• CPC Class Codes: G09G 2320/0653 Controlling or limiting the speed of brightness adjustment of the illumination source
• CPC Class Codes: G09G 2320/0673 for control of gamma adjustment, e.g. selecting another gamma curve
• CPC Class Codes: G09G 2330/021 Power management, e.g. power saving
• CPC Class Codes: G09G 2340/16 Determination of a pixel data signal depending on the signal applied in the previous frame
• CPC Class Codes: G09G 2360/16 Calculation or use of calculated indices related to luminance levels in display data
• CPC Class Codes: G09G 3/3406 Control of illumination source illumination devices structurally associated with liquid crystal cells G02F1/1336
• CPC Class Codes: G09G 3/3611 Control of matrices with row and column drivers
• CPC Class Codes: Y10S 348/913 Letterbox, e.g. display 16:9 aspect ratio image on 4:3 screen

Abstract

Embodiments of a system that includes one or more integrated circuits are described. During operation, the system receives a sequence of video images and a brightness setting of a light source which is configured to illuminate a display that is configured to display the video images, where the sequence of video images includes video signals. Then, the system determines an intensity setting of the light source on an image-by-image basis for the sequence of video images, where the intensity of a given video image is based on the brightness setting and brightness information contained in the video signals associated with the given video image. Next, the system synchronizes the intensity setting of the light source with a current video image to be displayed.

Claims

1. A system comprising one or more integrated circuits, wherein the one or more integrated circuits comprise include:

intensity calculation logic configured to determine an intensity setting of a light source on a frame-by-frame basis for video image data, wherein the intensity setting for the video image data corresponding to a first video image is based on a brightness setting and brightness information contained in the video data corresponding to the first video image, and wherein the light source is configured to illuminate an entire display that is configured to display a visual representation of the video image data; and

delay logic configured to delay the intensity setting of the light source to synchronize the intensity setting of the light source corresponding to the first video image with the display of a visual representation of the video image data corresponding to the first video image, wherein the video image data corresponding to the first video image is output separately from the delayed intensity setting of the light source, wherein the delay of the intensity setting of the light source is at least as long as a time interval associated with the first video image.

2. The system of claim 1, wherein the video image data comprises a frame of video.

3. The system of claim 1, wherein the determined intensity setting of the light source reduces power consumption of the light source.

4. The system of claim 1, wherein the light source comprises a light emitting diode.

5. The system of claim 1, wherein the light source comprises a fluorescent lamp.

6. The system of claim 1, wherein the one or more integrated circuits comprise extraction logic configured to calculate a brightness metric of the video image data, wherein the brightness metric corresponds to the brightness information.

7. The system of claim 6, wherein the brightness metric includes a histogram of brightness values in the video image data.

8. The system of claim 6, wherein the one or more integrated circuits comprise scaling logic configured to scale the video image data based on the brightness metric.

9. The system of claim 8, wherein the scaling logic is configured to scale the video image data based on a dynamic range of a mechanism that attenuates coupling of light from the light source to the display that is configured to display the visual representation of video image data.

10. The system of claim 8, wherein the scaling logic is configured to scale the video image data based on a mapping function associated with a portion of the brightness metric.

11. The system of claim 10, wherein a distortion metric is associated with the mapping function.

12. The system of claim 11, wherein the intensity setting of the light source is based on the distortion metric.

13. The system of claim 1, wherein the one or more integrated circuits comprise a filter configured to filter a change in intensity settings between the first video image and an adjacent second video image in the video image data based on a magnitude and a direction of the change in the intensity settings.

21. The system of claim 1, wherein the delay of the intensity setting of the light source is at least as long as a time interval associated with a corresponding video image to be displayed.

14. A method for synchronizing an intensity setting of a light source and a current video image to be displayed, comprising:

receiving video image data and a brightness setting of the light source which is configured to illuminate an entire display that is configured to display a visual representation of the video image data;

determining an intensity setting of the light source on a frame-by-frame basis for the video image data, wherein the intensity setting for the video image data corresponding to a video image is based on the brightness setting and brightness information contained in the video image data corresponding to the video image; and

delaying the intensity setting of the light source to synchronize the intensity setting of the light source corresponding to the video image with the display of a visual representation of the video image data corresponding to the video image, wherein the video image data corresponding to the video image is output separately from the delayed intensity setting of the light source, wherein the delay of the intensity setting of the light source is at least as long as a time interval associated with the video image.

15. A tangible, non-transitory, computer-readable medium, having stored thereon:

instructions to receive video image data and a brightness setting of a light source which is configured to illuminate an entire display that is configured to display a visual representation of the video image data;

instructions to determine an intensity setting of the light source on a frame-by-frame basis for the video image data, wherein the intensity setting for the video image data corresponding to a video image is based on the brightness setting and brightness information contained in the video image data corresponding to the video image; and

instructions to delay the intensity setting of the light source to synchronize the intensity setting of the light source corresponding to the video image with the display of a visual representation of the video image data corresponding to the video image, wherein the video image data corresponding to the video image is output separately from the delayed intensity setting of the light source, wherein the delay of the intensity setting of the light source is at least as long as a time interval associated with the video image.

16. An integrated circuit, comprising one or more sub-circuits, wherein the one or more sub-circuits are configured to:

receive video image data and a brightness setting of a light source which is configured to illuminate an entire display that is configured to display a visual representation of the video image data;

determine an intensity setting of the light source on a frame-by-frame basis for the video image data, wherein the intensity setting for video image data corresponding to a video image is based on the brightness setting and brightness information contained in the video image data; and

delay the intensity setting of the light source to synchronize the intensity setting of the light source corresponding to the video image with the display of a visual representation of the video image corresponding to the video image, wherein the video image data corresponding to the video image is output separately from the delayed intensity setting of the light source, wherein the delay of the intensity setting of the light source is at least as long as a time interval associated with the video image.

17. An integrated circuit, comprising:

logic configured to determine an intensity setting of a light source on a frame-by-frame basis for the video image data, wherein the intensity setting for the video image data corresponding to a video image is based on the brightness setting and brightness information contained in the video image data corresponding to the video image, and wherein the light source is configured to illuminate an entire display that is configured to display a visual representation of the video image data; and

delay logic configured to delay the intensity setting of the light source to synchronize the intensity setting of the light source corresponding to the first video image with the display of a visual representation of the video image data corresponding to the video image, wherein the current the video image data corresponding to the video image is output separately from the delayed intensity setting of the light source, wherein the delay of the intensity setting of the light source is at least as long as a time interval associated with the video image.

18. A computer system to determine an intensity setting of a light source, comprising:

a processor;

memory;

a program module, wherein the program module is stored in the memory and configurable to be executed by the processor, the program module comprising;

instructions to receive video image data and a brightness setting of a light source which is configured to illuminate an entire display that is configured to display a visual representation of the video image data;

instructions to determine an intensity setting of the light source on a frame-by-frame basis for the video image data, wherein the intensity setting for the video image data corresponding to a video image is based on the brightness setting and brightness information contained in the video image data corresponding to the video image; and

instructions to delay the intensity setting of the light source to synchronize the intensity setting of the light source corresponding to the video image with the display of a visual representation of the video image data corresponding to the video image, wherein the video image data corresponding to the video image is output separately from the delayed intensity setting of the light source, wherein the delay of the intensity setting of the light source is at least as long as a time interval associated with the video image.

19. A computer system configured to execute instructions to determine an intensity setting of a light source, comprising:

a processor;

a memory;

an instruction fetch unit within the processor configured to fetch;

instructions to receive video image data and a brightness setting of a light source which is configured to illuminate an entire display that is configured to display a visual representation of the video image data;

instructions to determine an intensity setting of the light source on a frame-by-frame basis for the video image data, wherein the intensity setting for the video image data corresponding to a given video image is based on the brightness setting and brightness information contained in the video image data corresponding to the video image; and

instructions to delay the intensity setting of the light source to synchronize the intensity setting of the light source corresponding to the video image with the display of a visual representation of the video image data corresponding to the video image, wherein the video image data corresponding to the video image is output separately from the delayed intensity setting of the light source, wherein the delay of the intensity setting of the light source is at least as long as a time interval associated with the video image; and

an execution unit within the processor configured to execute the instructions for receiving the video image data, the instructions to determine the intensity setting of the light source, and instructions to delay the intensity setting of the light source to synchronize the intensity setting of the light source corresponding to the video image with the display of a visual representation of the video image data corresponding to the video image to be displayed, wherein the video image data corresponding to the video image is output separately from the delayed intensity setting of the light source.

20. A portable device, comprising:

a display;

a light source configured to output light based on an intensity setting, wherein the light source is configured to illuminate the entire display;

an attenuation mechanism configured to modulate the output light incident on the display, wherein the display is configured to display a sequence of video images; and

one or more integrated circuits, wherein the one or more integrated circuits include;

intensity calculation logic configured to determine an intensity setting of a light source on a frame-by-frame basis for video image data, wherein the intensity setting of a video image is based on a brightness setting and brightness information contained in the video image data corresponding to the video image; and

delay logic configured to delay the intensity setting of the light source to synchronize the intensity setting of the light source corresponding to the first image with the display of a visual representation of the video image data corresponding to the video image, wherein the video image data corresponding to the video image is output separately from the delayed intensity setting of the light source, wherein the delay of the intensity setting of the light source is at least as long as a time interval associated with the video image.