Multi-Display Backlight Compensation via Embedded Controller

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Solution Overview

Problem

Computing devices with multiple display devices face challenges in maintaining consistent perceived brightness due to manufacturing variations, ambient light differences, and temperature fluctuations, leading to noticeable brightness disparities between displays.

Innovation Solution

An embedded controller measures current and ambient light for each display device, calculates a brightness ratio, and adjusts the current to the secondary display devices using PWM to match the brightness of a master display device, compensating for manufacturing tolerances, ambient light, and temperature variations.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If multiple display devices are used in a computing device, then the functionality and information processing capability are improved, but brightness consistency between displays deteriorates due to manufacturing variations

Engineering Contradiction:

Improvemulti-display functionalityVSAvoidbrightness consistency

Core Design Contradiction:

Adaptability or versatilityVSIllumination intensity

Solution Approach 1:

The patent adjusts the backlight parameters (current, voltage, or PWM duty cycle) of individual display devices based on measured brightness characteristics. The embedded controller modifies electrical parameters to compensate for manufacturing variations, achieving consistent perceived brightness across multiple displays without requiring manual calibration.

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The system implements a feedback mechanism where the embedded controller continuously monitors brightness characteristics of each display device and dynamically adjusts backlight parameters accordingly. This closed-loop control ensures that brightness consistency is maintained despite manufacturing tolerances and environmental variations.

Inventive Principle:

Principle #23Feedback

2Adaptability or versatility

If display devices are positioned in different ambient light conditions, then the adaptability to various usage scenarios is improved, but perceived brightness uniformity deteriorates

Engineering Contradiction:

Improveusage scenario flexibilityVSAvoidperceived brightness uniformity

Core Design Contradiction:

Adaptability or versatilityVSIllumination intensity

Solution Approach 1:

The embedded controller adjusts backlight parameters based on ambient light sensor readings from each display location. Displays in brighter environments receive increased backlight compensation, while displays in darker areas have reduced backlight output, maintaining uniform perceived brightness across all displays regardless of their ambient light conditions.

Inventive Principle:

Principle #35Parameter changes

3Adaptability or versatility

If display devices operate at different temperatures, then the adaptability to various operational configurations is improved, but brightness stability deteriorates

Engineering Contradiction:

Improveoperational configuration flexibilityVSAvoidbrightness stability

Core Design Contradiction:

Adaptability or versatilityVSStability of the object's composition

Solution Approach 1:

The system compensates for temperature-induced brightness variations by dynamically adjusting backlight parameters based on temperature sensor data. Displays operating at higher temperatures receive increased backlight compensation to counteract the natural dimming effect, while displays at lower temperatures have reduced backlight output, maintaining consistent brightness stability across all displays.

Inventive Principle:

Principle #35Parameter changes

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

This solution ensures that all display devices in a computing device appear to have similar brightness, enhancing user experience by automatically adjusting for variations caused by manufacturing, ambient light, and temperature differences.

Implementation Method 1

adjusts a backlight of the second display device by modifying a second current associated with the backlight of the second display device using pulse width modulation (PWM)

Methodology Applied

Scientific EffectPWM (Pulse Width Modulation): Phase Modulation

Data Source

PatentUS10510305B2Backlight compensation for a computing device with two or more display devices

Publication Date: 2019.12.17 DELL PROD LP

AI summary

In some implementations, a computing device may include a first display device and a second display device. An embedded controller may determine a first perceived brightness of the first display based on a first current and a first amount of ambient light associated with the first display device, determine a second perceived brightness of the second display device based on a second current and a second amount of ambient light associated with the second display device, and determine a ratio of the first perceived brightness to the second perceived brightness. The embedded controller may modify, based at least in part on the ratio, the second current to create a second modified amount of current associated with the second display device that modifies the second perceived brightness of the second display device to create a modified second perceived brightness of the second display device.