Display Stress Data Rate Control Under Buffer Size Limits

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Solution Overview

Problem

Existing rate control methods for OLED displays require a large number of iterations to determine sufficient compression, leading to inefficiencies in data fitting within the display buffer, which affects image quality due to OLED degradation over time.

Innovation Solution

A method and system for rate control that adjusts precision levels based on the current precision level, additional stress data precision, and buffer precision, allowing for efficient compression of stress data within a few iterations by encoding and decoding processes, including dithering to ensure data fits within the buffer.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If log-search rate control is used to determine compression, then sufficient compression is achieved, but six iterations or more are required

Engineering Contradiction:
Improvecompression accuracyVSAvoidnumber of iterations
Core Design Contradiction:
Measurement precisionVSLoss of time

Solution Approach 1:

The patent performs preliminary analysis of the stress data characteristics and buffer constraints before the main compression process. By pre-calculating the relationship between precision levels and compression ratios, and pre-identifying the target buffer size, the system avoids iterative trial-and-error, achieving accurate compression in fewer iterations

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent implements a feedback mechanism where the compression result from each iteration is immediately evaluated against the buffer constraint. Based on this feedback, the precision level is dynamically adjusted for the next iteration. This closed-loop control enables the system to converge to the optimal precision level much faster than traditional log-search methods

Inventive Principle:
Principle #23Feedback

2Reliability

If precision level is increased to maintain image quality, then OLED degradation compensation is improved, but buffer size requirements increase

Engineering Contradiction:
Improveimage qualityVSAvoidbuffer size
Core Design Contradiction:
ReliabilityVSVolume of stationary object

Solution Approach 1:

The patent dynamically changes the precision parameter based on the actual buffer availability and compression requirements. Instead of using a fixed high precision level that would always exceed buffer constraints, the system adjusts the precision parameter to achieve the minimum necessary quality while fitting within the buffer, effectively resolving the contradiction between quality and buffer size

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent makes the precision level dynamic rather than static. The precision adapts to the specific characteristics of the stress data and the available buffer space, allowing the system to maintain optimal image quality compensation while efficiently utilizing the buffer resources

Inventive Principle:
Principle #15Dynamics

Data Source

PatentEP4075418A1Simplified rate control for an additive iterative compression system
Publication Date: 2022.10.19 SAMSUNG DISPLAY CO LTD
  • EP4075418A1 patent drawingFigure 1
  • EP4075418A1 patent drawingFigure 2
  • EP4075418A1 patent drawingFigure 3

AI summary

A method of rate control of a display device includes receiving compressed stress data for a slice of a display, decompressing the compressed stress data to obtain reconstructed stress data for the slice, adding additional stress data to the reconstructed stress data to obtain updated stress data for the slice, encoding the updated stress data at a first precision level (pc) to generate first updated compressed stress data for the slice, in response to a size (bc) of the first updated compressed stress data for the slice of the display exceeding a size (bt) of a buffer, determining a second precision level (p) based on the first precision level (pc), a third precision level (ps) of the additional stress data, and a fourth precision level (pb) of the buffer, and encoding the updated stress data at the second precision level (p) to generate second updated compressed stress data.