Three-Panel Projector Phosphor Wheel Optical Path Design
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Three-panel-type projectors face challenges in miniaturization due to increased complexity and cost associated with a larger number of optical paths and components, particularly in the light source portion using a laser and phosphor, compared to single-panel projectors.
Innovation Solution
A three-panel-type projector design featuring a phosphor wheel that emits fluorescence and excitation light in opposite directions, with equal-length optical paths for each illumination system, simplifying the optical configuration and reducing the number of components by eliminating the need for a relay optical system.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If a three-panel-type projector uses a transmissive phosphor wheel with blue laser excitation light, then white light is generated for illuminating red, green, and blue display panels, but the optical system becomes more complex and the number of components increases compared to single-panel projectors
Solution Approach 1:
The patent divides the phosphor wheel into multiple independent phosphor layers, each emitting different wavelengths (yellow, orange, red). This segmentation allows the optical system to selectively extract specific wavelength bands for each display panel, reducing the need for complex wavelength separation components while maintaining three-panel illumination capability
Solution Approach 2:
The patent inverts the conventional transmissive phosphor wheel design by using a reflective phosphor wheel configuration. The phosphor layers are arranged to reflect light back through the laser light source, allowing excitation light to pass through once and fluorescence to be extracted in the opposite direction. This inversion simplifies the optical path and reduces the number of required optical components
2Measurement precision
If a three-panel-type projector uses separate laser and phosphor components for each color, then high image quality is achieved, but the number of constituent parts increases and cost increases compared to discharge lamp systems
Solution Approach 1:
The patent merges multiple phosphor materials (yellow, orange, red phosphors) onto a single rotating wheel structure, which is then illuminated by a single blue laser source. This combining approach maintains the high image quality of separate color sources while reducing the overall component count and system complexity compared to having separate lasers and phosphors for each color
Solution Approach 2:
The blue laser light source serves multiple functions: it directly illuminates the blue display panel and simultaneously excites the yellow, orange, and red phosphors on the wheel. This multi-functionality eliminates the need for separate light sources for each color channel, reducing component quantity while maintaining high image quality across all three panels
3Productivity
If a three-panel-type projector uses constant illumination for all panels, then higher light utilization factor and performance are achieved, but the optical path complexity and component count increase compared to time-division illumination
Solution Approach 1:
The patent uses a rotating phosphor wheel that continuously presents different phosphor layers to the laser beam, enabling continuous generation of all three color components (blue from direct laser, yellow/orange/red from phosphor fluorescence). This continuous action allows constant illumination of all three display panels simultaneously, achieving high light utilization factor without the need for complex time-division switching mechanisms
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 achieves high image quality with a simpler optical system, reducing the number of parts and costs while maintaining uniform illumination across all panels, facilitating miniaturization and improved performance.
Implementation Method 1
a phosphor wheel that, in response to the irradiation of excitation light that is used as first illumination light, emits fluorescence that contains second illumination light and third illumination light
Implementation Method 2
a first illumination optical system that guides excitation light that is emitted from the phosphor wheel to the first image display element; and second illumination optical system and third illumination optical system that guide the second illumination light and third illumination light that are contained in the fluorescence emitted from the phosphor wheel
Data Source
AI summary
A projector includes: a phosphor wheel that, in response to the irradiation of excitation light that is used as the first illumination light, generates fluorescence that contains second illumination light and third illumination light and emits the excitation light and fluorescence in opposite directions; first to third image display elements that are provided corresponding to the first to third illumination light; a first illumination optical system that guides the excitation light that was emitted from the phosphor wheel to the first image display element; and a second illumination optical system and third illumination optical system that guide the second illumination light and third illumination light that are contained in the fluorescence emitted from the phosphor wheel to the second image display element and to the third image display element. The lengths of the optical paths of the first, second, and third illumination optical systems are the same.