SYSTEM AND METHOD FOR FRAME BUFFER STORAGE AND RETRIEVAL IN ALTERNATING ORIENTATIONS

• US 20110227937A1
• Filed: 03/17/2010
• Published: 09/22/2011
• Est. Priority Date: 03/17/2010
• Status: Active Grant

• Current Assignee: Snaptrack Incorporated (Qualcomm, Inc.)
• Original Assignee: Qualcomm MEMS Technologies Incorporated (Qualcomm, Inc.)
• Inventors: Todorovich, Mark M.
• Granted Patent: US 8,659,611 B2
• Time in Patent Office: Days
• US Class Current: 345/545
• CPC Class Codes: G06F 16/71 Indexing; Data structures therefor; Storage structures
• CPC Class Codes: G06F 2212/1016 Performance improvement
• CPC Class Codes: G06F 2212/1041 Resource optimization
• CPC Class Codes: G06F 2213/0062 Bandwidth consumption reduction during transfers
• CPC Class Codes: G06F 3/147 using display panels
• CPC Class Codes: G09G 2310/04 Partial updating of the display screen
• CPC Class Codes: G09G 2340/0492 Change of orientation of the displayed image, e.g. upside-down, mirrored
• CPC Class Codes: G09G 2350/00 Solving problems of bandwidth in display systems
• CPC Class Codes: G09G 3/3466 based on interferometric effect
• CPC Class Codes: G09G 5/399 using two or more bit-mapped memories, the operations of which are switched in time, e.g. ping-pong buffers

Abstract

The present invention provides a method and apparatus for storing image data for successive frames in a frame buffer. Specifically, the method and apparatus allow for a display-sized frame buffer to be utilized where a host system provides image data in a format different from that which the display requires to be written to it while retaining the beneficial aspects of concurrent read and write operations from and to the frame buffer. Using this method a buffer controller receives image data from a host system in a first format (e.g. row-by-row) and writes it to the frame buffer in the first format. When the buffer is completely filled with the first frame, it is read out in a second format (e.g. column-by-column) by the buffer controller and provided to a display driver that writes the data to the display. As the first frame is read out in the second format, the buffer controller receives image data for a second frame from the host system in the first format, but rotates it before writing it to the frame buffer such that it is written to the frame buffer in the second format. This rotation allows the buffer controller to write to the frame buffer and the display driver to read from the frame buffer concurrently, despite the different image data format requirements of the host system and display. When the second frame is completely written to the buffer in the second format, the buffer controller then reads the buffer in the first format, and writes it to the display. At this point the process repeats. Thus, the benefits of concurrent read and write are preserved.

Claims

1. A method for processing image data for display, comprising:

for each incoming image frame, successively alternating between storing rows of the incoming image frame as rows in the frame buffer and storing rows of the incoming image frame as columns in the frame buffer while successively alternating between displaying rows of a frame buffer as columns on a display and displaying columns of the frame buffer as columns on the display.

2. The method of claim 1, wherein the frame buffer is the same size as the display.

3. The method of claim 1, wherein the display comprises electromechanical devices.

4. The method of claim 3, wherein the electromechanical devices are IMODs.

5. A method for processing image data for display, comprising:

(a) storing a first image frame in a frame buffer;

(b) reading a first column of the frame buffer for display as a column;

(c) rotating a first row of a second image frame and storing the rotated data in the first column of the frame buffer;

(d) reading a second column of the frame buffer for display as a column;

(e) rotating a second row of the second image frame and storing the rotated data in the second column of the frame buffer;

(f) repeating steps (b) through (e) until the first image frame has been read from the frame buffer and the second image frame has been stored in the frame buffer

(g) reading a first row of the frame buffer and rotating it for display as a column;

(h) storing a first row of a third image frame in the first row of the frame buffer;

(i) reading a second row of the frame buffer and rotating it for display as a column;

(j) storing a second row of a third image frame in the second row of the frame buffer;

(k) repeating steps (g) through (j) until the second image frame has been read from the frame buffer and the third image frame has been stored in the frame buffer; and

(l) repeating steps (b) through (k) continuously.

6. A method for processing image data for a display, comprising:

obtaining image data from a host system in a first format;

successively alternating between storing the image data in a frame buffer in the first format and a second format;

successively alternating between reading the image data from the frame buffer in the first format and the second format; and

displaying the image data in the second format.

7. The method of claim 6, wherein the frame buffer is the same size as the display.

8. The method of claim 6, wherein the first format is row-by-row and the second format is column-by-column.

9. The method of claim 6, wherein the first format is column-by-column and the second format is row-by-row.

10. The method of claim 6, wherein image data from a second frame is stored in the frame buffer concurrent with the reading of image data from a first frame.

11. The method of claim 6, wherein a read pointer reads the image data from the frame buffer and a write pointer writes the image data to the frame buffer.

12. The method of claim 11, wherein the write pointer always writes an element of image data for a particular frame before the read pointer reads that element of image data.

13. A display system comprising:

a display;

a frame buffer; and

logic circuitry configured to;

obtain image data from a host system in a first format;

successively alternate between storing the image data in a frame buffer in the first format and a second format;

successively alternate between reading the image data from the frame buffer in the first format and the second format; and

provide the image data for display in the second format.

14. The display system of claim 13, wherein the frame buffer is the same size as the display.

15. The display system of claim 13, wherein the first format is row-by-row and the second format is column-by-column.

16. The display system of claim 13, wherein the first format is column-by-column and the second format is row-by-row.

17. The display system of claim 13, wherein image data from a second frame is stored in the frame buffer concurrent with the reading of image data from a first frame.

18. The display system of claim 13, further configured to use a read pointer and a write pointer, wherein the read pointer reads the image data from the frame buffer and the write pointer writes the image data to the frame buffer.

19. The display system of claim 18, wherein the write pointer always writes an element of image data for a particular frame before the read pointer reads that element of image data.

20. The display system of claim 13, wherein the image data are displayed by an electromechanical device.

21. The display system of claim 20, wherein the electromechanical device is an IMOD.

22. A display system comprising:

means for storing image data;

means for obtaining image data from a host system in a first format;

means for successively alternating between storing the image data in the storage means in the first format and a second format;

means for successively alternating between reading the image data from the frame buffer in the first format and the second format; and

means for displaying the image data in the second format.