Variable Refresh Rate Backlight Pulsing for Motion Blur Reduction

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Solution Overview

Problem

Hold-type displays experience motion blur due to maintaining images for the entire frame duration, leading to perceived blurring of moving objects, and variable refresh rates exacerbate this issue with undesirable flicker and visual artifacts.

Innovation Solution

Pulse the backlight of hold-type displays twice for each frame, with the duration of the first pulse based on a predicted frame duration and the second pulse based on the difference between predicted and actual frame durations, adjusting pulse durations to minimize visual artifacts.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Object-affected harmful factors

If the backlight is pulsed for a fraction of the frame duration to reduce motion blur, then motion blur is reduced, but perceived brightness varies causing flicker

Engineering Contradiction:

Improvemotion blurVSAvoidperceived brightness stability

Core Design Contradiction:

Object-affected harmful factorsVSStability of the object's composition

Solution Approach 1:

The patent applies periodic backlight pulsing at the target frame rate (e.g., 144 Hz) to create consistent illumination intervals that reduce motion blur while maintaining stable perceived brightness through regular timing patterns

Inventive Principle:

Principle #19Periodic action

Solution Approach 2:

The patent changes the backlight illumination parameters by introducing a second pulse with adjusted duration and amplitude, transforming the single-pulse timing parameter into a dual-pulse timing pattern to compensate for brightness variations

Inventive Principle:

Principle #35Parameter changes

2Adaptability or versatility

If the frame rate varies to match content requirements, then adaptability is improved, but visual artifacts such as tearing, smearing, and stuttering occur

Engineering Contradiction:

Improveframe rate adaptabilityVSAvoidvisual artifacts

Core Design Contradiction:

Adaptability or versatilityVSObject-affected harmful factors

Solution Approach 1:

The patent predicts the frame duration before displaying the frame and pre-calculates the appropriate backlight pulse timing and duration, allowing the system to prepare compensation parameters in advance and reduce visual artifacts caused by variable refresh rates

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The patent uses feedback from the predicted versus actual frame duration comparison to dynamically adjust the second backlight pulse duration, creating a closed-loop control system that compensates for timing variations and reduces visual artifacts

Inventive Principle:

Principle #23Feedback

3Device complexity

If a single backlight pulse is used per frame, then device complexity is reduced, but motion blur and visual artifacts increase

Engineering Contradiction:

Improvebacklight control complexityVSAvoidmotion blur and visual artifacts

Core Design Contradiction:

Device complexityVSObject-affected harmful factors

Solution Approach 1:

The patent segments the backlight illumination into two distinct pulses within each frame period: a first pulse synchronized with the target frame rate and a second pulse timed based on actual frame duration, dividing the illumination function to simultaneously reduce motion blur and visual artifacts

Inventive Principle:

Principle #1Segmentation

Data Source

PatentUS20250209999A1Low motion blur displays with variable refresh rates

Publication Date: 2025.06.26 NVIDIA CORP

AI summary

Disclosed are systems and techniques for low motion blue displays with variable refresh rates. The techniques include generating a predicted frame duration for a first frame, determining an actual frame duration for the first frame, and causing the first frame to be displayed by operating a backlight of a display in a first mode. Operating the backlight of the display in the first mode includes pulsing the backlight of the display for the first frame at a first time for a fraction of the predicted frame duration and pulsing the backlight of the display for the first frame at a second time based on a difference between the predicted frame duration and the actual frame duration.