Laser Projector White Balance Control via Dynamic Output Adjustment

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Solution Overview

Problem

Conventional laser light source projectors using multiple laser sources for colors face challenges in maintaining white balance due to aging deterioration or temperature changes, which cause fluctuations in light output characteristics, especially when some laser sources degrade, leading to luminance imbalances among color groups.

Innovation Solution

A laser light source projector that adjusts the light output of remaining laser sources within each color group to compensate for degraded sources, ensuring constant white balance by increasing or reducing light outputs as needed, and implementing feedback control to maintain target values and prevent saturation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Stability of the object's composition

If light output from remaining light sources is reduced to match the most deteriorated light source, then white balance is maintained, but overall luminance is reduced

Engineering Contradiction:
Improvewhite balanceVSAvoidoverall luminance
Core Design Contradiction:
Stability of the object's compositionVSIllumination intensity

Solution Approach 1:

The patent adjusts the light output parameters of individual laser sources within each color group dynamically. When one or more laser sources deteriorate, the system changes the output parameters of remaining sources to compensate, maintaining overall luminance while preserving white balance through coordinated parameter adjustment across multiple light sources

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The system implements dynamic control of light output characteristics. Rather than statically reducing all light sources to match the most deteriorated one, the system dynamically adjusts individual source outputs based on real-time performance monitoring, enabling adaptive compensation that maintains both luminance and white balance

Inventive Principle:
Principle #15Dynamics

2Illumination intensity

If light output from laser light sources is increased to compensate for degradation, then luminance is maintained, but temperature increase occurs leading to further degradation

Engineering Contradiction:
Improvelight output luminanceVSAvoidlaser element temperature
Core Design Contradiction:
Illumination intensityVSTemperature

Solution Approach 1:

The system performs preliminary adjustments by distributing increased light output demand across multiple remaining laser sources before any single source experiences excessive temperature rise. This proactive load distribution prevents temperature-related degradation by avoiding concentration of thermal stress on individual elements

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent divides each color group into multiple laser light sources, allowing the system to segment the compensation task across several elements rather than overloading a single source. This segmentation enables better thermal management while maintaining required luminance levels through collective output from multiple sources

Inventive Principle:
Principle #1Segmentation

3Device complexity

If a single laser light source is used for each color, then device complexity is reduced, but white balance correction capability is lost when multiple colors are involved

Engineering Contradiction:
Improvenumber of laser light sourcesVSAvoidwhite balance correction capability
Core Design Contradiction:
Device complexityVSAdaptability or versatility

Solution Approach 1:

The patent segments each color group into multiple laser light sources while maintaining a modular structure. This segmentation provides the flexibility needed for white balance correction across multiple colors, as each source within a color group can be independently adjusted to compensate for deterioration, enabling adaptability without excessive complexity

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The system design allows each laser source to serve multiple functions: normal image projection and white balance compensation. By making the light source array multi-functional, the system achieves white balance correction capability across multiple colors while managing device complexity through unified control architecture that handles both standard projection and compensation operations

Inventive Principle:
Principle #6Universality (Multi-functionality)

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 approach maintains consistent white balance by preventing luminance differences among color groups, allowing the projector to keep light output levels stable and recover from temporary degradations, thereby ensuring accurate image projection.

Implementation Method 1

a Peltier element unit for cooling the laser light source

Methodology Applied
Scientific EffectPeltier effect: Peltier Effect

Data Source

PatentEP2653920B1Laser light source projector
Publication Date: 2021.07.21 MITSUBISHI ELECTRIC CORP
  • EP2653920B1 patent drawingFigure 1
  • EP2653920B1 patent drawingFigure 2
  • EP2653920B1 patent drawingFigure 3

AI summary

A laser light source projector includes a plurality of light sources of color groups each including a plurality of laser light sources. The laser light source projector projects an image by driving the laser light sources in each of the color groups. In response to change of the light output characteristics of one or a plurality of laser light sources in an arbitrary color group, light output from a remaining laser light source in the arbitrary color group is adjusted, thereby keeping white balance constant.