Spatiotemporal Dither for Pulsed Digital Display Flicker Reduction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Electronic displays using pulsed light emissions can experience visible flickering at low target luminance levels, especially at reduced frame rates, which affects image quality.
Innovation Solution
Spatiotemporal dithering is applied to the pulsing of pixels in grouped areas, where the ordering of sub-frames is adjusted to be out of phase across the group, effectively increasing the perceived frame rate and reducing flickering.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If pixels are pulsed at low frequency to achieve low target luminance levels, then energy consumption is reduced, but visible flickering occurs which degrades image quality
Solution Approach 1:
The display panel is divided into multiple pixel groups, where pixels within each group are driven with different sub-frame sequences. This segmentation allows the flicker artifacts to be distributed across different spatial locations and time periods, preventing synchronized flickering that would be visible to viewers while maintaining low frame rates for energy efficiency.
Solution Approach 2:
The patent implements periodic dithering patterns where pixel groups alternate between different sub-frame sequences in a cyclic manner. This periodic action creates out-of-phase pulsing behavior across pixel groups, effectively distributing the low-frequency pulsing artifacts over time and space, reducing visible flicker while maintaining energy-efficient low frame rate operation.
2Loss of energy
If frame rate is reduced to save power, then energy consumption decreases, but flickering artifacts become more visible
Solution Approach 1:
By segmenting the display into multiple pixel groups with different dithering patterns, the patent enables reduced frame rate operation without concentrated flicker artifacts. Each pixel group experiences different temporal patterns, and when viewed collectively, the flicker is distributed and less perceptible, allowing lower frame rates for power savings.
Solution Approach 2:
The patent transitions from temporal dithering alone to spatiotemporal dithering by introducing spatial variation across pixel groups. This adds a spatial dimension to the dithering approach, where flicker artifacts are not only distributed over time but also across different spatial locations, making them less visible while maintaining low frame rates.
3Device complexity
If pixels are driven in-phase to maintain simple control, then device complexity is low, but synchronized pulsing creates visible flicker
Solution Approach 1:
The patent segments pixel control into multiple groups, each with distinct dithering patterns. This segmentation increases control complexity only marginally while effectively eliminating synchronized pulsing artifacts. The segmented approach allows simple per-group control logic that collectively achieves artifact reduction.
Solution Approach 2:
The patent implements periodic dithering patterns across pixel groups that create out-of-phase operation. This periodic action distributes the control complexity in a systematic and manageable way, where each pixel group follows a simple periodic pattern that collectively eliminates synchronized pulsing without requiring complex real-time control logic.
Data Source
AI summary
In accordance with embodiments of the present disclosure, a device may include a pulsed emission electronic display having multiple display pixels in order to display an image frame. The display may pulse one or more display pixels of over a plurality of sub-frames within the image frame based on display image data. The device may also include image processing circuitry to generate the display image data based on source image data indicative of an image to be displayed during the image frame. Additionally, the image processing circuitry may dither an order of the plurality of sub-frames.