OVERLAY FOR DISPLAY SELF REFRESH

• US 20160180796A1
• Filed: 12/23/2014
• Published: 06/23/2016
• Est. Priority Date: 12/23/2014
• Status: Active Grant

• Current Assignee: Synaptics Incorporated
• Original Assignee: Synaptics Incorporated
• Inventors: MOREIN, Stephen L.
• Granted Patent: US 10,074,203 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: G06F 3/1415 with means for detecting differences between the image stored in the host and the images displayed on the displays
• CPC Class Codes: G06T 11/60 Editing figures and text; Combining figures or text
• CPC Class Codes: G09G 2320/103 Detection of image changes, e.g. determination of an index representative of the image change
• CPC Class Codes: G09G 2330/021 Power management, e.g. power saving
• CPC Class Codes: G09G 2340/02 Handling of images in compressed format, e.g. JPEG, MPEG
• CPC Class Codes: G09G 2340/12 Overlay of images, i.e. displayed pixel being the result of switching between the corresponding input pixels
• CPC Class Codes: G09G 2360/18 Use of a frame buffer in a display terminal, inclusive of the display panel
• CPC Class Codes: G09G 5/003 Details of a display terminal, the details relating to the control arrangement of the display terminal and to the interfaces thereto specific for a CRT G09G1/165; for a flat panel G09G3/2092
• CPC Class Codes: G09G 5/006 Details of the interface to the display terminal specific for a display terminal using a CRT G09G1/167; using a flat panel G09G3/2096; circuits for interfacing with colour displays G09G5/04
• CPC Class Codes: G09G 5/395 Arrangements specially adapted for transferring the contents of the bit-mapped memory to the screen G09G5/399 takes precedence

Abstract

A display device, a processing system, and a method are provided for updating a display device using self-refresh techniques. The described system is configured to overlay dynamic data from a source over a static image in the display device. Components of the described system may include the overlay for non-static image data, compression of the overlay, and dirty region tracking for the source display engine.

Claims

1. A processing system for a display, the processing system comprising:

a display memory configured to store a first frame of display update data;

a display driver module configured to operate in a self-refresh mode comprising updating a display using the first frame of display update data stored in the display memory;

wherein the display driver module is further configured to operate in a second mode comprising;

receiving, from a source, an overlay of display update data;

merging the overlay with the stored first frame of display update data to form a merged image; and

updating a display using the merged image.

2. The processing system of claim 1, wherein the overlay is compressed by the source prior to being provided to the display driver module.

3. The processing system of claim 1, wherein the merged image comprises a first plurality of pixels from the overlay and a second plurality of pixels from the first frame of display update data.

4. The processing system of claim 1, wherein the overlay of display update data comprises a plurality of transparent pixels, and wherein merging the overlay of display update data with the first frame of display update data comprises, for each pixel of display update data:

using a pixel from the first frame of display update data to form the merged image based on a determination that a corresponding pixel of the overlay is a transparent pixel; and

using a pixel from the overlay to form the merged image based on a determination that the pixel is not a transparent pixel.

5. The processing system of claim 1, wherein the merged image is not stored in the display memory.

6. The processing system of claim 1, wherein the overlay of display update data is generated based on a determination that a region of display has been changed, wherein the overlay comprises a first plurality of pixels corresponding to the region of the display that has been changed and a second plurality of pixels comprising transparent pixels.

7. A method for operating a display device, the method comprising:

storing a first frame of display update data in a display memory;

receiving an overlay of display update data from a source;

merging the overlay with the stored first frame of display update data to form a merged image; and

updating a display using the merged image.

8. The method of claim 7, wherein, the overlay of display update data is compressed prior to being provided to a display driver module.

9. The method of claim 7, wherein the merged image comprises a first plurality of pixels from the overlay and a second plurality of pixels from the first frame of display update data.

10. The method of claim 7, wherein the overlay of display update data comprises a plurality of transparent pixels, and wherein merging the overlay of display update data with the first frame of display update data comprises, for each pixel of display update data:

using a pixel from the first frame of display update data to form the merged image based on a determination that a corresponding pixel of the overlay is a transparent pixel; and

using a pixel from the overlay to form the merged image based on a determination that the pixel is not a transparent pixel.

11. The method of claim 7, wherein the merged image is not stored in the display memory.

12. The method of claim 7, further comprising:

generating, by operation of the source, the overlay of display update data based on a determination that a region of display has been changed, wherein the overlay comprises a first plurality of pixels corresponding to the region of the display that has been changed and a second plurality of pixels comprising transparent pixels.

13. The method of claim 7, further comprising:

marking, by operation of the source, one or more regions of the display as being changed based on the overlay; and

responsive to determining a threshold amount of regions of the display has been changed, providing a second frame of display update data to a display driver module.

14. An display device comprising:

a source configured to generate an overlay of display update data;

a processing system coupled to the source and comprising;

a display memory configured to store a first frame of display update data;

a display driver module configured to operate in a self-refresh mode comprising updating a display using the first frame of display update data stored in the display memory;

wherein the display driver module is further configured to operate in a second mode comprising;

merging the overlay with the first frame of display update data to form a merged image; and

updating a display using the merged image.

15. The display device of claim 14, wherein the source is configured to compress the overlay prior to providing the overlay to the display driver module.

16. The display device of claim 14, wherein the source is configured to provide an indication to the display driver module to store the first frame of display update data in the display memory.

17. The display device of claim 14, wherein the merged image comprises a first plurality of pixels from the overlay and a second plurality of pixels from the first frame of display update data.

18. The display device of claim 14, wherein the overlay of display update data comprises a plurality of transparent pixels, and wherein merging the overlay of display update data with the first frame of display update data comprises, for each pixel of display update data:

using a pixel from the first frame of display update data to form the merged image based on a determination that a corresponding pixel of the overlay is a transparent pixel; and

using a pixel from the overlay to form the merged image based on a determination that the pixel is not a transparent pixel.

19. The display device of claim 14, wherein the merged image is not stored in the display memory.

20. The display device of claim 14, wherein the source is configured to:

generate the overlay of display update data based on a determination that a region of display has been changed, wherein the overlay comprises a first plurality of pixels corresponding to the region of the display that has been changed and a second plurality of pixels comprising transparent pixels;

mark one or more regions of the display as being changed based on the generated overlay; and

responsive to determining a threshold amount of regions of the display has been changed, providing a second frame of display update data to the display driver module.