Extending the range of variable refresh rate displays

Patent metadata

Field	Value
Publication number	US-2016196801-A1
Application number	US-201514589560-A
Country	US
Kind code	A1
Filing date	Jan 5, 2015
Priority date	Jan 5, 2015
Publication date	Jul 7, 2016
Grant date	—

Abstract

Briefly, methods and apparatus to provide image content to, and display image content on, variable refresh rate displays with reduced input lag. The methods and apparatus allow for image tearing, or the displaying of image content from more than one video frame, when the render rate of a provided video frame falls outside the display refresh rate range of a variable refresh rate display when the display is refreshing with a previous frame (e.g. the display is in active refresh), thus reducing the input lag of the content of the provided video frame. The methods and apparatus may also prevent image tearing when the render rate of provided video frames is within the display refresh rate range of a display.

First claim

What is claimed is:

1 . A method of providing display content for a variable refresh rate display, the method comprising:
responsive to a new frame being rendered at a render rate outside of a display refresh rate range of the display while the display is refreshing with a previous frame, providing content from the new frame corresponding to a location on the display where the display is refreshing with the previous frame.

2 . The method of claim 1 , comprising determining that the new frame has been rendered at the render rate outside of the display refresh rate range of the display while the display is refreshing with the previous frame.

3 . The method of claim 2 , comprising providing content from the new frame for the location on the display corresponding to the first scan line of the display when it is determined that the new frame has not been rendered at the render rate outside of the display refresh rate range of the display while the display is refreshing with the previous frame.

4 . The method of claim 2 , wherein a determination that the new frame has been rendered at the render rate outside of the display refresh rate range of the display while the display is refreshing with the previous frame comprises determining that the render rate exceeds a maximum display refresh rate of the display.

5 . The method of claim 4 , comprising:
wherein a determination that the new frame has not been rendered at the render rate outside of the display refresh rate range of the display while the display is refreshing with the previous frame comprises determining that the render rate is less than or equal to the maximum display refresh rate of the display, preventing an image tear by not providing content from the new frame while the display is refreshing with the previous frame when it is determined the new frame has not been rendered at the render rate outside of the display refresh rate range of the display while the display is refreshing with the previous frame.

6 . The method of claim 2 , wherein a determination that the new frame has been rendered at the render rate outside of the display refresh rate range of the display while the display is refreshing with the previous frame comprises determining that the render rate is less than a minimum display refresh rate of the display.

7 . The method of claim 6 , comprising:
wherein a determination that the new frame has not been rendered at the render rate outside of the display refresh rate range of the display while the display is refreshing with the previous frame comprises determining that the render rate exceeds or is equal to the minimum display refresh rate of the display, preventing an image tear by not providing content from the new frame while the display is refreshing with the previous frame when it is determined that the new frame has not been rendered at the render rate outside of the display refresh rate range of the display while the display is refreshing with the previous frame.

8 . The method of claim 2 , wherein determining whether the new frame has been rendered at the render rate outside of the display refresh rate range of the display while the display is refreshing with the previous frame comprises determining that vertical synchronization is disabled.

9 . The method of claim 2 , wherein providing content from the new frame corresponding to the location on the display where the display is refreshing with the previous frame further comprises:
scheduling a display refresh at or near the maximum display refresh rate supported by the display; and providing content from the new frame for the location on the display corresponding to the first scan line of the display for display during the scheduled display refresh.

10 . A device capable of providing display content for a variable refresh rate display, the device comprising logic operative to provide content from a new frame corresponding to a location on the display where the display is refreshing with a previous frame in response to the new frame being rendered at a render rate outside of a display refresh rate range of the display while the display is refreshing with the previous frame.

11 . The device of claim 10 , wherein the logic is operative to determine that the new frame has been rendered at the render rate outside of the display refresh rate range of the display while the display is refreshing with the previous frame.

12 . The device of claim 11 , wherein the logic is operative to provide content from the new frame for the location on the display corresponding to the first scan line of the display when it is determined that the new frame has not been rendered at the render rate outside of the display refresh rate range of the display while the display is refreshing with the previous frame.

13 . The device of claim 11 , wherein the logic is operative to determine that the render rate exceeds a maximum display refresh rate of the display, wherein a determination that the new frame has been rendered at the render rate outside of the display refresh rate range of the display while the display is refreshing with the previous frame comprises determining that the render rate exceeds the maximum display refresh rate of the display.

14 . The device of claim 13 , wherein the logic is operative to:
determine that the render rate is less than or equal to the maximum display refresh rate of the display, wherein a determination that the new frame has not been rendered at the render rate outside of the display refresh rate range of the display while the display is refreshing with the previous frame comprises determining that the render rate is less than or equal to the maximum display refresh rate of the display; and prevent an image tear by not providing content from the new frame while the display is refreshing with the previous frame when it is determined the new frame has not been rendered at a render rate outside of the display refresh rate range of the display while the display is refreshing with the previous frame.

15 . The device of claim 11 , wherein the logic is operative to determine that the render rate is less than a minimum display refresh rate of the display, wherein a determination that the new frame has been rendered at the render rate outside of the display refresh rate range of the display while the display is refreshing with the previous frame comprises determining that the render rate is less than the minimum display refresh rate of the display.

16 . The device of claim 15 , wherein the logic is operative to:
determine that the render rate exceeds or is equal to the minimum display refresh rate of the display, wherein a determination that the new frame has not been rendered at the render rate outside of the display refresh rate range of the display while the display is refreshing with the previous frame comprises determining that the render rate exceeds or is equal to the minimum display refresh rate of the display; and prevent an image tear by not providing content from the new frame while the display is refreshing with the previous frame when it is determined the new frame has not been rendered at the render rate outside of the display refresh rate range of the display while the display is refreshing with the previous frame.

17 . A non-transitory computer readable medium comprising executable instructions that when executed cause an integrated circuit (IC) fabrication system to fabricate one or more ICs that comprise logic operative to provide content from a new frame corresponding to a location on the display where the disp

Assignees

• Ati Technologies Ulc

Inventors

• Glen David

Classifications

• G06T1/60

  Memory management · CPC title

• G09G5/18 Primary

  Timing circuits for raster scan displays (specially adapted for television H04N {; synchronisation between the display unit and other display units, videodisc player G09G5/12}) · CPC title

• G09G5/003

  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 title

• G09G2360/18

  Use of a frame buffer in a display terminal, inclusive of the display panel · CPC title

• G09G2370/04

  Exchange of auxiliary data, i.e. other than image data, between monitor and graphics controller · CPC title