Projector Lighting Device with Time-Division Wavelength Separation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional lighting devices for projectors struggle to achieve high color purity for blue light, limiting the reproduction of accurate color images due to the direct emission of blue light without passing through a color wheel, unlike red and green light which are filtered and adjusted for tone and purity.
Innovation Solution
A lighting device incorporating a first light source for excitation, a wavelength converter generating fluorescence, a second light source emitting a different wavelength range, and an optical path-combining element guiding these paths to a single emission path with a light separator to achieve time-division emission of specific wavelengths, ensuring all regions of the wavelength converter reflect fluorescence towards the combining element for improved color purity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If blue light from a second light source is directly combined with the emission optical path without passing through a color wheel, then the device complexity is reduced and ease of manufacture is improved, but the color purity of the blue light deteriorates
Solution Approach 1:
A color conversion element is introduced as an intermediary component in the blue light optical path. This element converts a portion of the blue light into other wavelengths (green and red), and the converted light is then combined with the remaining blue light through an optical path combining element. This mediator approach allows the blue light to undergo spectral modification similar to how red and green light are processed through the color wheel, thereby improving color purity while maintaining the simplified structure of direct blue light emission.
2Productivity
If all wavelength ranges are emitted simultaneously, then the productivity is improved and time consumption is reduced, but the measurement precision of color separation deteriorates
Solution Approach 1:
The patent implements a light separation element that periodically separates different wavelength ranges (blue, green, red) in the emission optical path. This periodic separation allows the system to process and control each color component at different time intervals, ensuring precise color separation and control. The periodic action maintains high productivity by rapidly switching between wavelength ranges while achieving the measurement precision needed for accurate color reproduction.
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 emission of high color purity light for all colors, including blue, enhancing the reproduction of accurate color images without the need for multiple light sources, reducing costs and device size while allowing for adjustable color tones and improved color freedom.
Implementation Method 1
a wavelength convertor which generates fluorescence containing at least a first wavelength range and a second wavelength range by excitation with the excitation light
Implementation Method 2
all of the region forms a reflection optical path which reflects the fluorescence toward the optical path-combining element
Data Source
AI summary
A lighting device includes a first light source which emits excitation light, a wavelength convertor which generates fluorescence containing at least a first wavelength range and a second wavelength range by excitation with the excitation light, a second light source which emits light containing a third wavelength range different from the first wavelength range and the second wavelength range, an optical path-combining element which combines an optical path for the fluorescence from the wavelength convertor and an optical path for the light from the second light source, so as to guide the combined optical paths to a single emission optical path, and a light separator disposed in the emission optical path, which obtains and emits at least the first wavelength range and the second wavelength range of the fluorescence and at least the third wavelength range of the light from the second light source.