Variable Refresh Rate Display Frame Time Balancing

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Variable refresh rate (VRR) displays experience screen flicker due to charge build-up when alternate frames have differing frame times, as the charge drifts from a net zero position.

Innovation Solution

Implementing a balance tracking and correction algorithm by the display driver to monitor and adjust the frame timing, ensuring that the total time spent in odd and even frames remains balanced, thereby preventing charge build-up and flicker.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If variable refresh rate is used to adapt to different frame rates, then productivity and adaptability are improved, but charge balance stability deteriorates causing flicker

Engineering Contradiction:

Improverefresh rate adaptabilityVSAvoidcharge balance stability

Core Design Contradiction:

Adaptability or versatilityVSStability of the object's composition

Solution Approach 1:

The display driver tracks the actual frame times of alternate frames and uses this feedback to determine when to initiate balance correction. The system continuously monitors the charge balance state and adjusts frame presentation timing based on real-time measurements, creating a closed-loop control system that maintains charge balance while preserving VRR adaptability

Inventive Principle:

Principle #23Feedback

Solution Approach 2:

The system predicts when balance correction will be needed by monitoring the current charge balance state and frame timing patterns. By anticipating the point at which charge balance will become unbalanced, the display driver proactively adjusts frame presentation timing to prevent flicker before it occurs, rather than reacting after balance has been violated

Inventive Principle:

Principle #10Preliminary action

2Object-affected harmful factors

If frame timing is adjusted to maintain charge balance, then flicker is reduced, but frame presentation timing precision deteriorates

Engineering Contradiction:

ImproveflickerVSAvoidframe timing precision

Core Design Contradiction:

Object-affected harmful factorsVSManufacturing precision

Solution Approach 1:

The system applies partial correction by only adjusting the timing of specific frames (e.g., every other frame or only when balance deviation exceeds a threshold) rather than continuously adjusting all frame timing. This selective approach reduces flicker while minimizing the impact on overall timing precision and frame rate stability

Inventive Principle:

Principle #16Partial or excessive action

Data Source

PatentUS12288534B2Balancing alternate frame times on a variable refresh rate display

Publication Date: 2025.04.29 INTEL CORP

AI summary

In one embodiment, a new frame is to be presented on a display. A frame time is predicted for the new frame along with a current balance for a set of previously presented frames. A frame pattern for the new frame is determined based on the predicted frame time and the current balance.