Phosphor Wheel Irradiation Geometry for Laser Projectors
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Solution Overview
Problem
Existing projector designs using laser light sources require multiple blue lasers, leading to high costs and a large light source apparatus, and do not efficiently generate white light for image display.
Innovation Solution
A projector design that utilizes a blue laser as a light source to generate blue and yellow light, incorporating a rectangular light generating lens and a phosphor wheel coated with phosphor, where the excitation light is irradiated at specific angles to optimize the irradiation region on the phosphor wheel, enhancing the B light utilization rate by diffusing the blue light and expanding its area.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If two blue laser light sources are used to generate white light, then the white light generation capability is improved, but the cost and apparatus size increase
Solution Approach 1:
The patent combines the functions of two separate blue laser light sources into a single blue laser light source by using a phosphor wheel that rotates to present different phosphor materials to the blue laser beam. This merging approach maintains the capability to generate white light with multiple spectral components while reducing the number of laser sources needed, thereby decreasing apparatus size and cost.
Solution Approach 2:
The phosphor wheel serves multiple functions: it acts as a beam splitter, a wavelength converter, and a spectral distributor. By rotating the phosphor wheel with different phosphor materials positioned at different angular locations, a single blue laser light source can generate multiple wavelength bands (blue, green, yellow-green, red) that would otherwise require multiple separate laser sources,从而实现一物多用.
2Use of energy by moving object
If a phosphor wheel with specific angular arrangement is used, then the B light utilization rate is improved, but the manufacturing precision requirements increase
Solution Approach 1:
The phosphor wheel is designed with different phosphor materials applied to specific angular regions rather than uniformly across the entire wheel. Each angular sector is optimized for a specific wavelength conversion function, with the center of the rectangular irradiation region positioned within specific angular ranges (0°-45°, 135°-225°, or 315°-360°). This local optimization allows the system to achieve high B light utilization by directing blue laser light to the most appropriate phosphor material for each wavelength band.
Solution Approach 2:
The patent specifies precise angular parameter ranges for positioning the center of the rectangular irradiation region on the phosphor wheel (e.g., 0° ≤ θ ≤ 45°, 135° ≤ θ ≤ 225°, or 315° ≤ θ < 360°). By controlling these angular parameters within defined ranges rather than requiring exact single-value positioning, the system achieves high B light utilization while providing manufacturing tolerance, thus balancing performance with manufacturability.
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 design effectively generates white light from a laser light source, improving the B light utilization rate and reducing the projector's size and cost, while maintaining efficient image display capabilities.
Implementation Method 1
a phosphor wheel that is coated with a phosphor that is irradiated with the excitation light of the rectangular shape to emit yellow light
Data Source
AI summary
A projector generates white light from a laser light source and uses the white light for image display. The white light generator has a rectangular light generating lens that generates excitation light of a rectangular shape from the blue light of a blue laser and a phosphor wheel, coated with a phosphor that is irradiated with the excitation light, to emit yellow light. In the phosphor wheel, a length in the vertical direction of a rectangular shape of an irradiation region is represented by v, and a length in the horizontal direction is represented by h, wherein h<v; and a center of the rectangular shape is within any one of a region having an angle of 45° or more and 135° or less and a region having an angle of 225° or more and 315° or less in the phosphor coat region of the phosphor wheel.