Dual Scan Out Display System for VR Latency Reduction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current VR systems face challenges in reducing motion-to-photon latency, particularly in phone-based VR systems where the lack of synchronized scanning between left and right eye displays causes discomfort, and in OLED-based VR systems where high refresh rates require increased pixel clock support, while LCD-based systems struggle with slow response times for low persistence and low latency.
Innovation Solution
Implementing a dual scan architecture that uses two sets of column and row drivers to scan the left and right halves of the display simultaneously, with data provided by separate pipes or ports, allowing for reduced latency and relaxed pixel clock requirements, and supporting higher refresh rates and resolutions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If single scan architecture is used in phone-based VR systems, then device complexity is reduced, but motion-to-photon latency increases and left-right eye synchronization is lost causing discomfort
Solution Approach 1:
The display panel is divided into two independent scanning regions (left eye and right eye) with separate row drivers for each region. This segmentation allows simultaneous scanning of both eyes' displays, eliminating the sequential scanning delay that caused motion-to-photon latency in single-scan architectures while maintaining manageable device complexity through modular driver design.
2Productivity
If higher pixel clock rates are used to support high refresh rates in OLED-based VR systems, then refresh rate increases, but power consumption increases and system complexity increases
Solution Approach 1:
The pixel clock signal is segmented into two separate clock domains, one for each eye's display region. Each region operates at the required refresh rate with its own optimized pixel clock, allowing high refresh rates to be achieved without requiring a single high-frequency clock that would consume excessive power. The segmentation enables independent optimization of power consumption for each scanning region.
3Device complexity
If single scan architecture is used, then device complexity is reduced, but display synchronization between left and right eyes deteriorates causing user discomfort
Solution Approach 1:
The display controller is segmented into two independent scanning engines, each with its own row driver and pixel clock domain. This segmentation enables completely independent timing control for left and right eye displays, ensuring perfect synchronization for stereoscopic viewing. Each segment can be independently optimized and calibrated, maintaining display synchronization stability while keeping the overall driver architecture manageable through modular design.
4Ease of manufacture
If LCD panels are used in VR systems, then manufacturing cost is reduced, but response time increases making low persistence and low latency difficult to achieve
Solution Approach 1:
The dual scan architecture implements periodic refreshing of each eye's display region independently, with optimized timing parameters for each scan period. This periodic action allows LCD panels to achieve lower effective persistence by controlling the timing of pixel updates more precisely, reducing the duration each pixel state is maintained and thereby reducing perceived persistence and latency while maintaining compatibility with standard LCD manufacturing.
Data Source
AI summary
A dual scan out display system and method for performing the same are described. In one embodiment, the computing system comprises a display and a controller to provide data for separate portions of the display simultaneously using dual scanout.