Reference EOTF Generation for APL-Dependent Display Certification

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Solution Overview

Problem

Display devices fail certification processes due to non-zero luminance at black level and varying peak luminance based on average picture level (APL), leading to inconsistent power consumption and certification failures.

Innovation Solution

A new reference electro-optical transfer function (EOTF) is generated using electrical-electrical transfer function (EETF) equations, adjusting luminance values to account for varying peak luminance and power consumption, ensuring compliance with certification standards.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Use of energy by moving object

If display devices regulate power consumption based on average picture level (APL), then power consumption is optimized, but peak luminance varies causing certification failures

Engineering Contradiction:

Improvepower consumptionVSAvoidcertification compliance

Core Design Contradiction:

Use of energy by moving objectVSReliability

Solution Approach 1:

The patent applies dynamics by making the reference EOTF adaptive rather than fixed. The system dynamically adjusts the reference EOTF based on the actual peak luminance measured during certification, allowing the transfer function to adapt to the display device's power-regulated luminance variations while maintaining accurate colorimetric measurements

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The patent changes the parameter of peak luminance from a fixed certification requirement to a variable input parameter. By measuring the actual peak luminance and using it to generate a customized reference EOTF, the system accommodates power consumption regulation while ensuring certification compliance through parameter adaptation

Inventive Principle:

Principle #35Parameter changes

2Use of energy by moving object

If display devices provide non-zero black level luminance, then power consumption is reduced, but certification standards requiring 0 nits are not met

Engineering Contradiction:

Improvepower consumptionVSAvoidluminance accuracy

Core Design Contradiction:

Use of energy by moving objectVSManufacturing precision

Solution Approach 1:

The patent treats the black level luminance parameter as variable rather than fixed at zero. By measuring the actual black level and incorporating it into the reference EOTF generation process, the system creates a customized transfer function that accurately represents the display's actual luminance characteristics while maintaining certification compliance

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent substitutes the mechanical/certification requirement of exactly 0 nits black level with a measurement-based approach. Instead of forcing the display to meet an arbitrary zero luminance standard, the system measures the actual black level and uses it as the reference point for generating the customized EOTF

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

3Ease of manufacture

If fixed reference EOTF is used during certification, then certification process is simple, but devices with power regulation fail despite good performance

Engineering Contradiction:

Improvecertification process simplicityVSAvoiddevice compatibility

Core Design Contradiction:

Ease of manufactureVSAdaptability or versatility

Solution Approach 1:

The patent applies preliminary action by measuring the display device's actual luminance characteristics (peak luminance and black level) before generating the reference EOTF. This pre-characterization allows the system to create a customized reference that accurately represents the specific device, enabling both simplicity and adaptability

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The patent segments the certification process into distinct phases: measurement phase where device characteristics are captured, and generation phase where the customized reference EOTF is created. This segmentation allows the system to maintain simplicity in each individual step while achieving adaptability through the overall process

Inventive Principle:

Principle #1Segmentation

Data Source

PatentUS12553774B2Method to generate reference EOTFs for display measurements

Publication Date: 2026.02.17 ATI TECHNOLOGIES ULC

AI summary

An apparatus and method for adjusting reference transfer functions used during a certification process. In various implementations, a display testing system includes multiple display devices under test and a measurement device. An optics capturing device sends information to the measurement device based on light information received from a display device under test. For display devices that regulate power consumption based on average picture level (APL) of the test image, the measurement device generates a new reference electro-optical transfer function (EOTF) based at least upon the varying peak luminance values based on changing APLs. For display devices that do not provide a minimum luminance of 0 nits at Perceptual Quantizer (PQ) code 0 of the ideal PQ EOTF, the measurement device generates a new reference EOTF based at least in part on using electrical-electrical transfer function (EETF) equations.