# US 11,113,886 B2 · Dual-screen display method for eliminating AR/VR picture tearing and AR/VR display device

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- Number: US 11,113,886 B2
- Document ID: US11113886B2
- Status: Granted
- Kind: B2
- Application number: 16/384,119
- Filed: 2019-04-15
- Published: 2020-03-26
- Granted: 2021-09-07
- Earliest claimed: 2018-09-20
- Assignees: Beijing Boe Optoelectronics Technology Co., Ltd.; Boe Technology Group Co., Ltd.
- Applicants: Beijing BOE Optoelectronics Technology Co., Ltd.; BOE Technology Group Co., Ltd.
- Inventors: Bin Zhao; Lixin Wang; Xi Li; Jianwen Suo; Qingwen Fan; Jinbao Peng; Ruifeng Qin; Yuanjie Lu; Jinghua Miao; Yukun Sun; Xuefeng Wang; Wenyu Li; Lili Chen; Hao Zhang
- Web page: https://patentgrep.com/patent/US11113886B2

## CPC

- G06T 19/006: {Mixed reality (object pose determination, tracking or camera calibration for mixed reality G06T7/00)}
- G09G 5/12: Synchronisation between the display unit and other units, e.g. other display units, video-disc players
- G02B 27/017: {Head mounted}
- G06F 3/1446: {display composed of modules, e.g. video walls}
- G06T 15/005: {General purpose rendering architectures}
- G06V 20/20: in augmented reality scenes
- G09G 5/399: using two or more bit-mapped memories, the operations of which are switched in time, e.g. ping-pong buffers
- G09G 2320/0257: Reduction of after-image effects
- G09G 2320/0266: Reduction of sub-frame artefacts
- G06T: IMAGE DATA PROCESSING OR GENERATION, IN GENERAL
- G09G: ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION (arrangements for transferring data between digital computers and displays G06F3/14; static indicating arrangements comprising an association of a number of separate sources or light control cells G09F9/00; static indicating arrangements comprising integral associations of a number of light sources H01J, H01K, H10H, H05B33/12; scanning, transmission or reproduction of documents or the like, e.g. facsimile transmission, details thereof H04N1/00)
- G02B: OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G06F: ELECTRIC DIGITAL DATA PROCESSING (computer systems based on specific computational models G06N)
- G06V: IMAGE OR VIDEO RECOGNITION OR UNDERSTANDING

## Abstract

The present disclosure proposes a dual-screen display method for eliminating AR/VR picture tearing and an AR/VR display device, each single screen in a dual-screen for the dual-screen display method being divided into a first half-screen and a second half-screen respectively. The method includes: performing rendering and scanning in parallel for the first half-screen and the second half-screen in unit of half a frame. A start time of scanning the second half-screen is adjusted to eliminate a picture tearing phenomenon.

## Claims

### Claim 1

A dual-screen display method for eliminating Augmented Reality (AR)/Virtual Reality (VR) picture tearing, each single screen in a dual-screen for the dual-screen display method being divided into a first half-screen and a second half-screen respectively the picture tearing is caused by a backlight black frame insertion for turning off a backlight upon a response of liquid crystal and turning on the backlight after the end of the response, and, the method comprising:
performing rendering and scanning in parallel for the first half-screen and the second half-screen in unit of half a frame,
wherein a rendering time of the frame is greater than a scanning time of the frame, and
a start time of scanning the second half-screen is adjusted to eliminate a picture tearing phenomenon,
wherein performing rendering and scanning in parallel for the first half-screen and the second half-screen in unit of half a frame comprises:
scanning the first half-screen during a first time period in which a second half-frame is rendered, wherein the second half-frame is displayed on the second half-screen, wherein the first time period is between a first vertical sync signal Vsync1 and a first a1 sync signal sync1; and
scanning the second half-screen during a second time period in which a first half-frame is rendered, wherein the first half-frame is displayed on the first half-screen, wherein the second time period is between the first sync signal sync1 and a second vertical sync signal Vsync2; and
wherein the rendering of the second half-frame and the scanning of the first half-screen start at the same time and a duration for the rendering of the second half-frame is greater than that for the scanning of the first half-screen;
wherein the rendering of the first half-frame and the scanning of the second half-screen start at the same time and a duration for the rendering of the first half-frame is greater than that for the scanning of the second half-screen.

### Claim 2 (depends on 1)

The dual-screen display method for eliminating AR/VR picture tearing according to claim 1, wherein the scanning of the second half-screen starts at the end of the rendering of the second half-frame.

### Claim 3 (depends on 1)

An Augmented Reality (AR)/Virtual Reality (VR) display device using the dual-screen display method for eliminating AR/VR picture tearing according to claim 1, comprising:
a buffer, comprising a first buffer region for storing rendering data of a first half-frame and a second buffer region for storing rendering data of a second half-frame, or a first buffer region for storing rendering data of a first frame and a second buffer region for storing rendering data of a second frame;
a rendering circuit;
a scanning circuit; and
a control circuit configured to control the rendering circuit to write data into the buffer and control the scanning circuit to read data from the buffer,
wherein the control circuit is configured to adjust a start time of reading data from the second buffer region by the scanning circuit to eliminate a picture tearing phenomenon.

### Claim 4 (depends on 3)

The AR/VR display device according to claim 3, wherein the control circuit is configured to:
control the scanning circuit to read data from the first buffer region during a time period in which the rendering circuit writes data into the second buffer region; and
control the scanning circuit to read data from the second buffer region during a time period in which the rendering circuit writes data into the first buffer region.

### Claim 5 (depends on 3)

The AR/VR display device according to claim 3, wherein the control circuit is configured to:
control the scanning circuit to start reading data from the second buffer region when the rendering circuit completes writing data into the second buffer region.

### Claim 6 (depends on 5)

The AR/VR display device according to claim 5, wherein the control circuit is configured to:
control the scanning circuit to start reading data from the first buffer region when the rendering circuit starts writing data into the second buffer region.

### Claim 7 (depends on 5)

The AR/VR display device according to claim 5, wherein the control circuit is configured to:
control the scanning circuit to complete reading data from the first buffer region when the rendering circuit completes writing data into the second buffer region.

### Claim 8

A dual-screen display method for eliminating Augmented Reality (AR)/Virtual Reality (VR) picture tearing, a dual-screen for the dual-screen display method being divided into a first screen and a second screen respectively, the picture tearing is caused by a backlight black frame insertion for turning off a backlight upon a response of liquid crystal and turning on the backlight after the end of the response, and the method comprising:
performing rendering and scanning in parallel for the first screen and the second screen in unit of a frame,
wherein a rendering time of the frame is greater than a scanning time of the frame, and
a start time of scanning the second screen is adjusted to eliminate a picture tearing phenomenon,
wherein performing rendering and scanning in parallel for the first screen and the second screen in unit of a frame comprises:
scanning the first screen during a first time period in which a second frame is rendered, wherein the second frame is displayed on the second screen, wherein the first time period is between a first vertical sync signal Vsync1 and a first a1 sync signal sync1; and
scanning the second screen during a second time period in which a first frame is rendered, wherein the first frame is displayed on the first screen, wherein the second time period is between the first sync signal sync1 and a second vertical sync signal Vsync2,
wherein the scanning of the first screen and the rendering of the second frame start at the same time and a duration for the rendering of the second frame is greater than that for the scanning of the first screen;
wherein the rendering of the first frame and the scanning of the second screen start at the same time and a duration for the rendering of the first frame is greater than that for the scanning of the second screen.

### Claim 9 (depends on 8)

The dual-screen display method for eliminating AR/VR picture tearing according to claim 8, wherein the scanning of the second screen starts at the end of the rendering of the second frame.