Compact Light Source Device for Projectors
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Solution Overview
Problem
Existing light source devices for projectors require a blue light source unit in addition to a light source unit for emitting fluorescence, leading to increased device size when generating white color illumination.
Innovation Solution
A light source device comprising a first light source emitting a first wavelength band, a second light source emitting a second wavelength band, a wavelength conversion section with a phosphor, a polarization splitting/combining element, a dichroic mirror, a retardation plate, a diffusion section, and a condensing optical section to convert and combine lights, achieving compact configuration and efficient white light generation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If a blue light source unit is added in addition to a light source unit for emitting fluorescence to generate white color illumination, then the white light generation capability is improved, but the device size increases
Solution Approach 1:
The patent combines the blue light source unit and the fluorescence light source unit into a single integrated light source device. The blue LED emits both blue light directly and excites the phosphor layer to generate yellow light, which are then combined to produce white light. This merging of functions into one compact unit resolves the contradiction by achieving white light generation without requiring separate, bulky light source units.
Solution Approach 2:
The blue LED serves multiple functions simultaneously: it acts as a direct blue light source and also serves as an excitation source for the phosphor material to generate yellow light. This multi-functionality allows the single blue LED to replace what would traditionally require separate blue and yellow light sources, thereby reducing device size while maintaining white light generation capability.
2Illumination intensity
If multiple light source units are used to generate white light, then the illumination quality is improved, but the device complexity increases
Solution Approach 1:
The patent merges multiple light generation functions into a single integrated structure where the blue LED and phosphor layer work together as one unit. The blue LED excites the phosphor, and both the emitted blue light and the phosphor-generated yellow light are combined through optical elements to produce white light. This integration significantly reduces device complexity compared to using separate, independently controlled light source units.
Solution Approach 2:
The patent uses a composite light generation system combining inorganic phosphor materials with the blue LED. The phosphor layer, composed of specific phosphor particles with defined properties, works in conjunction with the blue LED to generate the yellow component of white light. This composite approach achieves high-quality white light with controlled color temperature and efficiency while maintaining a relatively simple device structure.
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
The solution enables the generation of white light with improved light use efficiency and compact device configuration, allowing for reduced size while maintaining excellent light modulation and projection capabilities.
Implementation Method 1
a wavelength conversion section which includes a phosphor, and which is configured to convert the first light emitted from the first light source into third light in a third wavelength band different from the first wavelength band
Implementation Method 2
a polarization splitting/combining element which is disposed in a light path of the second light, and which has a polarization splitting function with respect to the second light
Implementation Method 3
a dichroic mirror configured to reflect the second light which is emitted from the second light source and which proceeds via the polarization splitting/combining element, toward the polarization splitting/combining element, and transmit the third light emitted from the wavelength conversion section
Implementation Method 4
a condensing optical section configured to collect the third light which is emitted form the wavelength conversion section and is transmitted through the dichroic mirror, and the second light reflected by the dichroic mirror
Data Source
AI summary
A light source device according to the present disclosure includes a first light source, a second light source, a wavelength conversion section, a polarization splitting/combining element, a dichroic mirror for reflecting second light and transmitting third light emitted from the wavelength conversion section, a retardation plate, a diffusion section, and a condensing optical section. Condensing optical section has a first end part, a second end part, and a reflecting part. Second light proceeding via the polarization splitting/combining element is transmitted through the condensing optical section from the second end part toward the first end part, and then enters the dichroic mirror. Second light reflected by the dichroic mirror passes through the condensing optical section and then enters the polarization splitting/combining element. Third light passes through the condensing optical section and then enters the polarization splitting/combining element. Polarization splitting/combining element combines the second light and the third light with each other.