Display with spatial and temporal refresh rate buffers

Patent metadata

Field	Value
Publication number	US-9524694-B2
Application number	US-201414527672-A
Country	US
Kind code	B2
Filing date	Oct 29, 2014
Priority date	Oct 29, 2014
Publication date	Dec 20, 2016
Grant date	Dec 20, 2016

Abstract

A display may have an array of pixels. The display may be controlled using display driver circuitry. The display driver circuitry may analyze image data to be displayed on the array. When static content is detected, the rate at which the pixels are refreshed may be adjusted to conserve power. If a static image is detected, the gate lines may be asserted at a lower refresh rate than if moving content is detected. To avoid visible artifacts, the display driver circuitry may use temporal and spatial refresh rate buffers. Temporal buffers ensure that refresh rates are changed gradually as a function of time, thereby minimizing flicker. Spatial refresh rate buffers are used to provide a smooth transition between low refresh rate and high refresh rate regions in a display as a function of position.

First claim

What is claimed is:

1. A method, comprising:
processing image data with display driver circuitry in a display to identify refresh rate buffers to use in refreshing pixels in an array of pixels; and
with the display driver circuitry, refreshing pixels in the array of pixels at a first refresh rate, a second refresh rate that is different that the first refresh rate, and at least one intermediate refresh rate associated with an identified refresh rate buffer, wherein the at least one intermediate refresh rate is between the first and second refresh rates, wherein the identified refresh rate buffer comprises a temporal refresh rate buffer and wherein refreshing the pixels comprises:
refreshing the pixels in the array at the first refresh rate during a first time period, refreshing the pixels in the array at the second refresh rate during a second time period, and refreshing the pixels in the array at the at least one intermediate refresh rate during the temporal refresh rate buffer between the first and second time periods, wherein an amount of intermediate refresh rates that are included in the at least one intermediate refresh rate is determined based on a rate difference between the first refresh rate and the second refresh rate.

2. A method of operating an array of pixels that displays images based on image data, comprising:
processing the image data with display driver circuitry in a display;
identifying static content in a first portion of the array;
identifying moving content in a second portion of the array;
refreshing pixels in the first portion of the array at a minimum refresh rate;
refreshing pixels in the second portion of the array at a maximum refresh rate;
based on a difference between the maximum refresh rate and the minimum refresh rate, determining an amount of intermediate refresh rates to be used in a spatial buffer region of the array, wherein the spatial buffer region of the array is interposed between the first portion of the array and the second portion of the array; and
refreshing pixels in the spatial buffer region of the array at the intermediate refresh rates.

3. The method defined in claim 2 , wherein determining the amount of intermediate refresh rates to be used in the spatial buffer region of the array comprises determining that one intermediate refresh rate will be used in the spatial buffer region of the array.

4. The method defined in claim 2 , wherein determining the amount of intermediate refresh rates to be used in the spatial buffer region of the array comprises determining that two intermediate refresh rates will be used in the spatial buffer region of the array, wherein the two intermediate refresh rates comprise first and second intermediate refresh rates, wherein the second intermediate refresh rate is greater than the first intermediate refresh rate, wherein refreshing the pixels in the spatial buffer region of the array at the intermediate refresh rates comprises refreshing a first portion of the spatial buffer region of the array at the first intermediate refresh rate, wherein refreshing the pixels in the spatial buffer region of the array at the intermediate refresh rates comprises refreshing a second portion of the spatial buffer region of the array at the second intermediate refresh rate, wherein the first portion of the spatial buffer region is adjacent to the first portion of the array, and wherein the second portion of the spatial buffer region is adjacent to the second portion of the array.

Assignees

• Apple Inc

Inventors

• Wang Chaohao
• Chen Cheng
• Jiang Shih-Chyuan Fan
• Ge Zhibing

Classifications

• G09G2320/103

  Detection of image changes, e.g. determination of an index representative of the image change · CPC title

• G09G3/3648 Primary

  using an active matrix (G09G3/367 - G09G3/3696 take precedence) · CPC title

• G09G2340/0435

  Change or adaptation of the frame rate of the video stream · CPC title

• G09G5/001

  Arbitration of resources in a display system, e.g. control of access to frame buffer by video controller and/or main processor · CPC title

• G09G5/02 Primary

  characterised by the way in which colour is displayed {(details of colour display specific for CRTs G09G1/28; specific for flat matrix panels other than liquid crystal displays G09G3/2003; specific for liquid crystal displays G09G3/3607)} · CPC title