Rotating Color Wheel Light Source System for Projection

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Conventional two chip DLP projection systems suffer from low utilization efficiency of compensation lights due to scattering losses when compensation lights are incident on phosphor materials, resulting in color coordinates of red and green lights deviating from the standard color gamut.

Innovation Solution

A light source system incorporating a rotating color wheel with distinct regions for excitation and compensation light sources, where compensation lights are directly transmitted rather than illuminated on phosphor materials, allowing for improved color gamut correction without scattering loss, utilizing a controller to manage light source activation intervals and a partially coated filter to reflect and transmit light effectively.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If compensation lights are incident on phosphor materials to correct color gamut, then color coordinates of red and green lights are closer to standard color gamut, but utilization efficiency of compensation lights is reduced due to scattering losses

Engineering Contradiction:
Improvecolor coordinates accuracyVSAvoidutilization efficiency of compensation lights
Core Design Contradiction:
Manufacturing precisionVSLoss of energy

Solution Approach 1:

The rotating color wheel is divided into distinct regions: a first region with phosphor material for wavelength conversion, and a second region without phosphor material for direct transmission of compensation lights. This segmentation allows compensation lights to bypass the phosphor material entirely during specific time intervals, eliminating scattering losses while maintaining color gamut correction capability.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The system uses periodic rotation of the color wheel to alternately present the first region (phosphor) and second region (transmission) to the excitation light and compensation lights. During rotation, compensation lights are transmitted through the second region without interacting with phosphor material, achieving periodic direct transmission that eliminates scattering losses while maintaining temporal synchronization with the DMD modulation cycles.

Inventive Principle:
Principle #19Periodic action

2Loss of energy

If a rotating color wheel with distinct regions is used to transmit compensation lights directly, then utilization efficiency of compensation lights is improved, but device complexity increases

Engineering Contradiction:
Improveutilization efficiency of compensation lightsVSAvoidstructure complexity
Core Design Contradiction:
Loss of energyVSDevice complexity

Solution Approach 1:

The rotating color wheel serves multiple functions simultaneously: it performs wavelength conversion for the excitation light through the phosphor-containing first region, transmits compensation lights directly through the phosphor-free second region, and provides temporal multiplexing for different light sources. This multi-functionality consolidates several optical functions into a single component, reducing overall system complexity despite the sophisticated operation.

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

Solution Approach 2:

The patent combines the functions of wavelength conversion, light transmission, and temporal multiplexing into a single rotating color wheel assembly. By merging these functions into one component rather than using separate elements for each function, the system reduces the number of optical components and simplifies the overall optical path management.

Inventive Principle:
Principle #5Merging (Combining)

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

Enhances the utilization efficiency of compensation lights, ensuring color coordinates align closer to standard color gamuts like DCI and REC.709, thereby improving the color accuracy and consistency of projected images.

Implementation Method 1

the first region is illuminated by the excitation light and converts it to a light sequence including at least two colors

Methodology Applied
Scientific EffectFluorescence: Fluorescence

Implementation Method 2

during the third time intervals, the second region transmits the compensation light

Methodology Applied
Scientific EffectLight transmission:

Implementation Method 3

a partially coated filter to reflect and transmit light effectively

Methodology Applied
Scientific EffectReflection: Reflection

Data Source

PatentEP3282315B1Light source system and projection system
Publication Date: 2021.07.21 APPOTRONICS CORP LTD
  • EP3282315B1 patent drawingFigure 1~3
  • EP3282315B1 patent drawingFigure 4~6
  • EP3282315B1 patent drawingFigure 7~8

AI summary

A light source system and a projection system. The light source system comprises: an excitation light source (101) for emitting excitation light in at least a first time sequence and a second time sequence; a compensation light source (102) for emitting compensation light in at least a third time sequence, the compensation light emitted by the compensation light source (102) comprising laser of at least one color; and a rotating color wheel (103), comprising at least a first region (201) and a second region (202), wherein the first region (201) generates light of at least two different colors in time sequence under the irradiation of the excitation light in the first time sequence and the second time sequence, and the second region (202) is used for transmitting the compensation light in at least the third time sequence. The light of the at least two different colors comprises at least one type of wide-spectrum fluorescence, and the laser of the at least one color is used for compensating for the fluorescence or light split from the fluorescence. In this way, the compensation light is directly transmitted without being irradiated upon fluorescent powder, scattering loss of the compensation light is reduced, and utilization rate of the compensation light is increased