Serial Wavelength Conversion Units for Uniform Projector Illumination
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Solution Overview
Problem
Existing light source apparatuses for projectors emit lights with different wavelengths, resulting in uneven light ray angular distribution, leading to color unevenness in projection images due to the inclusion of both converted and unconverted lights in the emission spectrum.
Innovation Solution
A light source apparatus with serially coupled wavelength conversion units, where each unit generates distinct converted lights, and an optical configuration that ensures only converted lights are extracted, using dichroic layers and light collection systems to manage excitation and converted light paths, maintaining consistent light ray angular distribution across wavelengths.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If a light source and wavelength conversion member are combined to generate converted light, then wavelength conversion is achieved, but unconverted excitation light remains in the emission spectrum causing color unevenness
Solution Approach 1:
The patent extracts and removes the unconverted excitation light from the emission spectrum using optical filters. The filter selectively transmits the converted light while blocking the excitation light, thereby eliminating the harmful unconverted light that causes color unevenness in the projection image.
Solution Approach 2:
The patent introduces an optical filter as an intermediary component between the wavelength conversion member and the projection optics. This mediator selectively separates the desired converted light from the unwanted excitation light, resolving the color uniformity issue without affecting the wavelength conversion process.
2Adaptability or versatility
If multiple wavelengths are emitted from the light source apparatus, then color diversity is achieved, but light ray angular distribution becomes uneven across wavelengths
Solution Approach 1:
The patent applies wavelength-specific optical properties to different components. The optical filter is designed with specific transmission characteristics for different wavelengths, and the optical system is optimized to handle the angular distribution characteristics of each wavelength band, ensuring uniform overall performance despite multi-wavelength emission.
3Use of energy by moving object
If excitation light and converted light are both present in the emission, then energy utilization is improved, but color accuracy deteriorates due to angular distribution differences
Solution Approach 1:
The patent selectively extracts and removes the excitation light component from the emission spectrum using optical filters. This eliminates the source of color inaccuracy while preserving the converted light that carries the desired color information, thereby maintaining color accuracy without sacrificing energy utilization.
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 configuration ensures uniform illumination and prevents color unevenness in projectors by eliminating unconverted excitation light from the emission, enhancing reliability and safety while reducing the need for color wheels and integrator optics.
Implementation Method 1
a light source and a rod-shaped wavelength conversion member that performs wavelength conversion of a light from the light source
Data Source
AI summary
A light source apparatus (1) according to the present disclosure includes a wavelength conversion device (10) that includes two or more wavelength conversion units (11-13) serially coupled in a first direction. The wavelength conversion device (10) has a configuration in which the two or more wavelength conversion units (11-13) generate respective converted lights having wavelengths different from each other to generate two or more converted lights. The two or more wavelength conversion units (11-13) each include a first end surface and a second end surface that are formed in a direction parallel to the first direction, and a light entering surface (43) that is formed in a second direction different from the first direction and which an excitation light for generating the converted light enters. The first end surface (41) of one wavelength conversion unit (13) positioned at one end of the wavelength conversion device (10) of the two or more wavelength conversion units (11-13) is configured to be a light extraction surface from which the two or more converted lights are extracted out of the excitation light and the two or more converted lights.