Display Luminance Scaling for Ambient Light Adaptation

Solution Overview

Problem

Display devices, particularly transmissive LCDs, face challenges in maintaining picture quality in varying ambient light conditions, as reducing backlight brightness leads to a lower perceived image quality, and users struggle to discern details in bright environments due to insufficient pixel luminance and backlight intensity.

Innovation Solution

A display system dynamically adjusts content luminance and backlight brightness based on ambient light levels by determining a minimum viewable threshold and shifting pixel luminance values to ensure the darkest pixels meet or exceed this threshold, using processors and ambient light sensors to generate modified images that enhance perceivable details in both bright and dim environments.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Use of energy by moving object

If backlight brightness is reduced to conserve power, then power consumption decreases, but image quality and visual discernment deteriorate

Engineering Contradiction:

Improvepower consumptionVSAvoidimage quality

Core Design Contradiction:

Use of energy by moving objectVSIllumination intensity

Solution Approach 1:

The system dynamically adjusts content luminance and backlight brightness based on real-time ambient light level detection. The processor modifies pixel luminance values and backlight intensity adaptively, transitioning between different brightness states depending on environmental conditions, thereby optimizing the balance between power consumption and image quality

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The system changes the luminance parameter of displayed content by shifting pixel luminance values. When ambient light levels change, the processor applies luminance transformations to adjust content brightness independently, allowing the display to maintain optimal visibility while managing power consumption through coordinated content and backlight adjustments

Inventive Principle:

Principle #35Parameter changes

2Illumination intensity

If content luminance is increased to improve visibility in bright ambient light, then visual discernment improves, but power consumption increases

Engineering Contradiction:

ImprovevisibilityVSAvoidpower consumption

Core Design Contradiction:

Illumination intensityVSUse of energy by moving object

Solution Approach 1:

The system dynamically adjusts content luminance and backlight brightness based on real-time ambient light level detection. The processor modifies pixel luminance values and backlight intensity adaptively, transitioning between different brightness states depending on environmental conditions, thereby optimizing the balance between power consumption and image quality

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The system changes the luminance parameter of displayed content by shifting pixel luminance values. When ambient light levels change, the processor applies luminance transformations to adjust content brightness independently, allowing the display to maintain optimal visibility while managing power consumption through coordinated content and backlight adjustments

Inventive Principle:

Principle #35Parameter changes

3Adaptability or versatility

If ambient light sensor and processing algorithms are added to enable dynamic adjustment, then adaptability to lighting conditions improves, but device complexity increases

Engineering Contradiction:

Improveadaptability to lighting conditionsVSAvoiddevice complexity

Core Design Contradiction:

Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The processor performs multiple functions: it processes display content, detects ambient light levels through the sensor, determines appropriate luminance adjustments, and coordinates both content and backlight adjustments. By consolidating these functions in the existing processor rather than adding dedicated hardware, the system achieves multi-functionality with minimal increase in overall device complexity

Inventive Principle:

Principle #6Universality (Multi-functionality)

Data Source

PatentUS11145240B2Dynamic scaling of content luminance and backlight

Publication Date: 2021.10.12 ATI TECHNOLOGIES ULC

AI summary

A method for dynamic scaling of content luminance and backlight level includes determining, using one or more processors of a display system, an ambient light level of a local environment proximate the display system. Based on the ambient light level being brighter than a first ambient light threshold, it is determined that the display system is in a normal room or a bright environment. A minimum viewable threshold representing a minimum pixel luminance value perceivable by a user in the ambient light level of the local environment is determined. The method further includes generating a modified display image by shifting the pixel luminance values of one or more pixels of an input image such that a darkest pixel value of the modified display image is equal to or greater than the minimum viewable threshold before transmitting the modified display image for display.