Projector Light Source Filter Switching for Green Color Purity
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Solution Overview
Problem
Existing light source apparatuses in projectors struggle to switch between color-reproducibility-oriented and luminance-oriented modes effectively, leading to a decrease in green light purity and deteriorated color reproducibility when using phosphors, and they lack the capability to adjust between these modes.
Innovation Solution
A light source apparatus with a first light source section outputting polarized blue and red light, a wavelength converter to generate green light, a light combiner to combine these lights, and a movable filter to selectively attenuate green light, allowing mode switching by adjusting the filter's position.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If a phosphor is used to generate green light, then the light source apparatus can emit green light, but the purity of the green light decreases compared to a green laser, deteriorating color reproducibility
Solution Approach 1:
The patent applies local quality by using different light sources for different color requirements: a blue light source with phosphor for green light generation, and a red light source for red light generation. This allows each light source to be optimized for its specific wavelength band, achieving high color purity in the red channel while maintaining adequate green light emission through phosphor conversion.
Solution Approach 2:
The patent changes the wavelength parameters by using a blue light source (first wavelength band) that is converted to green light (third wavelength band) through phosphor, while separately using a red light source (second wavelength band). This parameter transformation allows the system to achieve high color purity in the red channel while maintaining green light emission, resolving the contradiction between phosphor-based green light generation and color purity requirements.
2Adaptability or versatility
If a light source apparatus uses phosphor to generate color light, then it can achieve certain color output, but it cannot switch between color-reproducibility-oriented mode and luminance-oriented mode
Solution Approach 1:
The patent implements dynamics by making the filter movable between a first position (where green light passes through) and a second position (where green light is blocked). This dynamic reconfiguration allows the system to switch between color-reproducibility-oriented mode (first position) and luminance-oriented mode (second position), enabling adaptability while maintaining color purity through the phosphor-based green light generation when needed.
3Manufacturing precision
If narrow-band filtering is applied to achieve effective use of red light, then color purity improves, but the light source apparatus remains incapable of switching between color-reproducibility-oriented mode and luminance-oriented mode
Solution Approach 1:
The patent resolves this contradiction by adding dynamic movability to the filter system. The filter can be positioned at the first position to allow green light transmission for color-reproducibility mode, or moved to the second position to block green light for luminance mode. This dynamic adjustment capability is superimposed on the existing narrow-band filtering for red light, enabling both high red light purity and mode switching functionality simultaneously.
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 apparatus enhances color reproducibility by narrowing the green light wavelength band and maintaining luminance, enabling seamless switching between color-reproducibility and luminance-oriented modes while minimizing brightness loss.
Implementation Method 1
a wavelength converter that converts the first light into third light that belongs to a third wavelength band different from the first and second wavelength bands
Implementation Method 2
a light combiner that combines the first light, the second light, and the third light with one another and outputs the combined light
Implementation Method 3
a filter that receives the third light and attenuates light that belongs to a wavelength band that is part of the third wavelength band
Implementation Method 4
the light combiner reflects light formed of the first polarized component and transmits light formed of the second polarized component out of the first light output from the first light source section
Data Source
AI summary
A light source apparatus according to an aspect of the present disclosure includes a first light source section that outputs first light containing a first polarized component and a second polarized component, a second light source section that outputs second light, a wavelength converter that converts the first light into third light, a light combiner that combines the first light, the second light, and the third light, and a filter that attenuates light of the third wavelength band. The light combiner reflects the first polarized component and transmits the second polarized component to cause one of the first polarized component and the second polarized component to exit toward the wavelength converter, and transmits the first light and the second light or the third light and reflects the third light or the first light and the second light. The filter is movable.