Method and apparatus for generating images using a color field sequential display

• US 8,711,167 B2
• Filed: 05/10/2011
• Issued: 04/29/2014
• Est. Priority Date: 05/10/2011
• Status: Active Grant

• Current Assignee: NVIDIA Corporation
• Original Assignee: NVIDIA Corporation
• Inventors: Wyatt, David
• Primary Examiner(s): Sajous, Wesner
• Application Number:
  US13/104,867
• Publication Number:
  US 20120287139A1
• Time in Patent Office: 1,085 Days
• Field of Search: 345/84, 345/87, 345/109, 345/581, 345/589, 345600-601, 345591-592, 345/606, 345545-549, 345/204, 345690-691, 345/694, 345/22, 345/36, 345/56, 345/63, 345 76- 77, 345/89, 345/102, 348 40- 42, 348 70- 71, 348251-256, 348268-269, 348427-430, 348/435, 348/439, 348455-456, 348/459, 348/478, 348513-514, 348536-539, 348/552, 348/557, 348/711, 348714-715, 359/26, 359227-228, 359/230, 359/237, 359/251, 359/253, 359/255, 359/283, 359/290, 359/389, 382/162, 382/167, 382/254, 382/274, 382/276, 382/305
• US Class Current: 345/589
• CPC Class Codes: G09G 2310/0235 Field-sequential colour display
• CPC Class Codes: G09G 2320/0252 Improving the response speed
• 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 2352/00 Parallel handling of streams of display data
• CPC Class Codes: G09G 2360/121 using a cache memory
• CPC Class Codes: G09G 3/003 to produce spatial visual effects
• CPC Class Codes: G09G 5/363 Graphics controllers
• CPC Class Codes: G09G 5/39 Control of the bit-mapped memory

Abstract

One embodiment of the present invention sets forth a technique for generating and transmitting video frame data from a graphics processing unit (GPU) to a color field sequential display device. A frame buffer image comprising per-pixel packed color channels is transformed to a frame buffer image comprising regions corresponding to the color channels with vertical blanking regions inserted between color sub-field regions. Each region of the transformed frame buffer image is sequentially transmitted to the color field sequential display device for display of the corresponding color channel. Backlight illumination for each color channel is controlled by the GPU for temporal alignment with display of each color channel during a vertical blanking interval. The GPU may compensate an individual pixel'"'"'s color channel value based on a corresponding previous color channel value in order to minimize crosstalk between neighboring color fields.

Claims

1. A method for displaying color frame information on a color field sequential display, the method comprising:

reading pixel data from an input frame buffer that is organized as packed color channels, wherein a separate color channel exists for each color in the color field of the sequential display;

extracting color channel information from the pixel data for each color channel shifting and masking the pixel data for each color channel being extracted;

generating frame buffer write data from the color channel information; and

storing the frame buffer write data as color sub-frame information in a target frame buffer.

2. The method of claim 1, further comprising the step of displaying the color sub-frame information stored in the target frame buffer on the color field sequential display.

3. The method of claim 1, wherein the step of generating comprises accumulating color channel information to form at least one word of write data for each color channel.

4. The method of claim 3, wherein the step of generating further comprises performing at least one color space conversion operation on the color channel information to compute the at least one word of write data.

5. The method of claim 2, wherein the color sub-frame information is organized in the target frame buffer to form a separate color sub-frame for each color channel.

6. The method of claim 5, wherein, for each independent color sub-frame, the step of displaying comprises:

directing a backlight within the color field sequential display to turn off;

transmitting contents of the independent color sub-frame to the color field sequential display; and

directing the backlight within the color field sequential display to turn on a color light source corresponding to the color channel associated with the independent color sub-frame.

7. The method of claim 6, wherein the backlight is directed to turn on during a time interval that maximizes illumination time for a corresponding color sub-frame that has been written to the color field sequential display.

8. The method of claim 6, wherein, for each independent color sub-frame, the step of transmitting contents comprises:

reading current frame data from the independent color sub-frame and previous frame data for a corresponding, previously displayed independent color sub-frame;

computing compensated pixel values based on the current frame data and the previous frame data; and

transmitting the compensated pixel values to the color field sequential display.

9. The method of claim 2, wherein the color sub-frame information is organized in the target frame buffer to include an independent color field for each color channel residing within a single frame.

10. The method of claim 9, wherein, for each independent color field, the step of displaying comprises:

directing a backlight within the color field sequential display to turn off;

transmitting contents of the color field to the color field sequential display based on a pixel clock operating at a first frequency;

transmitting vertical blanking lines to the color field sequential display based on the pixel clock operating at a second frequency that is less than the first frequency; and

directing the backlight within the color field sequential display to turn on a color light source corresponding to the color channel associated with the independent color field.

11. The method of claim 10, wherein transmitting the contents based on the first frequency and transmitting vertical blanking lines based on the second frequency results in a specified frame refresh time.

12. The method of claim 10, wherein the backlight is directed to turn on during a time interval that maximizes illumination time for a corresponding color field that has been written to the color field sequential display.

13. The method of claim 10, wherein, for each independent color field, the step of transmitting contents comprises:

reading current field data from the independent color field and previous field data for a corresponding, previously displayed independent color field;

computing compensated pixel values based on the current field data and the previous field data; and

transmitting the compensated pixel values to the color field sequential display.

14. An apparatus configured to generate color field sequential display information, comprising:

a graphics processing unit configured to;

read pixel data from an input frame buffer that is organized as packed color channels, wherein a separate color channel exists for each color in the color field of the sequential display;

extract color channel information from the pixel data for each color channel by shifting and masking the pixel data for each color channel being extracted;

generate frame buffer write data from the color channel information; and

store the frame buffer write data as color sub-frame information in a target frame buffer.

15. The apparatus of claim 14, wherein the color sub-frame information is organized in the target frame buffer to include an independent color sub-frame for each color channel, and wherein the graphics processing unit is further configured to:

direct a backlight within the color field sequential display to turn off;

transmit contents of the independent color sub-frame to the color field sequential display; and

direct the backlight within the color field sequential display to turn on a color light source corresponding to the color channel associated with the independent color sub-frame.

16. The apparatus of claim 15, wherein to transmit, for each independent color sub-frame, the graphics processing unit is configured to:

read current frame data from the independent color sub-frame and previous frame data for a corresponding, previously displayed independent color sub-frame;

compute compensated pixel values based on the current frame data and the previous frame data; and

transmit the compensated pixel values to the color field sequential display.

17. The apparatus of claim 14, wherein the color sub-frame information is organized in the target frame buffer to include an independent color field for each color channel residing within a single frame, and wherein, for each independent color field, the graphics processing unit is further configured to:

direct a backlight within the color field sequential display to turn off;

transmit contents of the independent color field to the color field sequential display based on a pixel clock operating at a first frequency;

transmit vertical blanking lines to the color field sequential display based on the pixel clock operating at a second frequency that is less than the first frequency; and

direct the backlight within the color field sequential display to turn on a color light source corresponding to the color channel associated with the independent color field.

18. The apparatus of claim 17, wherein transmitting the contents based on the first frequency and transmitting vertical blanking lines based on the second frequency results in a specified frame refresh time.

19. The apparatus of claim 17, wherein the backlight is directed to turn on during a time interval that maximizes illumination time for a corresponding color field that has been written to the color field sequential display.

20. The apparatus of claim 17, wherein to transmit contents, for each independent color field, the graphics processing unit is configured to:

read current field data from the independent color field and previous field data for a corresponding, previously displayed independent color field;

compute compensated pixel values based on the current field data and the previous field data; and

transmit the compensated pixel values to the color field sequential display.

21. A computer-readable storage medium including instructions that, when executed by a processor, cause the processor to perform the steps of:

reading pixel data from an input frame buffer that is organized as packed color channels, wherein a separate color channel exists for each color in the color field of the sequential display;

extracting color channel information from the pixel data for each color channel by shifting and masking the pixel data for each color channel being extracted;

generating frame buffer write data from the color channel information; and

storing the frame buffer write data as color sub-frame information in a target frame buffer.

22. The computer-readable storage medium of claim 21, wherein the color sub-frame information is organized in the target frame buffer to include an independent color sub-frame for each channel, further comprising instructions that cause the processor to perform the steps of:

directing a backlight within the color field sequential display to turn off;

transmitting contents of the independent color sub-frame to the color field sequential display; and

directing the backlight within the color field sequential display to turn on a color light source corresponding to the color channel associated with the independent color sub-frame.

23. The computer-readable storage medium of claim 22, wherein, for each independent color sub-frame, the step of transmitting contents comprises:

reading current frame data from the independent color sub-frame and previous frame data for a corresponding, previously displayed independent color sub-frame;

computing compensated pixel values based on the current frame data and the previous frame data; and

transmitting the compensated pixel values to the color field sequential display.

24. The computer-readable storage medium of claim 21, wherein the color sub-frame information is organized in the target frame buffer to include an independent color field for each color channel residing within a single frame, and for each independent color field, further comprising instructions that cause the processor to perform the steps of:

directing a backlight within the color field sequential display to turn off;

transmitting contents of the color field to the color field sequential display based on a pixel clock operating at a first frequency;

transmitting vertical blanking lines to the color field sequential display based on the pixel clock operating at a second frequency that is less than the first frequency; and

directing the backlight within the color field sequential display to turn on a color light source corresponding to the color channel associated with the independent color field.

25. The computer-readable storage medium of claim 24, wherein, for each independent color field, the step of transmitting contents comprises:

reading current field data from the independent color field and previous field data for a corresponding, previously displayed independent color field;

computing compensated pixel values based on the current field data and the previous field data; and

transmitting the compensated pixel values to the color field sequential display.