Separate Color Illumination Paths for Laser Projection
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing image projection apparatuses face issues with color unevenness and reduced utilization efficiency of laser lights due to differing beam profiles from multiple light sources, as optimizing the illumination optical system for one color affects others, and increasing diffusion angles to mitigate unevenness leads to power loss.
Innovation Solution
The apparatus employs separate optical systems for each color, using distinct sets of optical elements to uniformize intensity distributions for red, green, and blue laser lights, with independent adjustments to minimize power loss and optimize each beam profile.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If the illumination optical system is made appropriate with respect to any one of the laser lights, then color uniformity for that specific color is improved, but color unevenness is caused in the projection image for other laser lights
Solution Approach 1:
The illumination optical system is divided into separate optical paths for different colors (red, green, blue laser lights). Each color has its own illumination optical system with independently optimized optical elements, allowing each subsystem to be tuned for its specific wavelength without affecting others, thereby eliminating color unevenness while maintaining uniformity.
2Manufacturing precision
If the diffusion angle of a diffusion plate is set to be large to suppress color unevenness, then color uniformity is improved, but power loss is caused in the laser lights
Solution Approach 1:
Instead of using a large diffusion angle that uniformly scatters all light, the patent employs separate illumination optical systems for each color with locally optimized diffusion characteristics. Each system uses diffusion plates with angles and properties specifically matched to its laser light's beam profile, achieving color uniformity while minimizing unnecessary light scattering and power loss.
3Device complexity
If a single illumination optical system is used for all laser lights, then device complexity is reduced, but utilization efficiency of laser lights decreases due to power loss
Solution Approach 1:
The illumination optical system is segmented into separate subsystems for red, green, and blue laser lights. Each subsystem independently guides its specific laser light to the display element with optimized optical elements, preventing power loss from mismatched diffusion angles while maintaining manageable overall system complexity through modular design.
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 approach effectively suppresses color unevenness and maintains high utilization efficiency of laser lights by optimizing each color's optical elements separately, resulting in a natural and high-quality projection image.
Implementation Method 1
an optical element of a first system configured to uniformize an intensity distribution of one of the laser lights and guide resultant laser light to the display element; and an optical element of a second system configured to uniformize an intensity distribution of another of the laser lights
Data Source
AI summary
An image projection apparatus includes: a plurality of light sources configured to respectively emit laser lights of colors different from each other; at least one display element configured to modulate each of the laser lights emitted from the plurality of light sources, on the basis of a video signal; an illumination optical system configured to guide the laser lights emitted from the plurality of light sources, to the display element; and a projection lens configured to project the laser lights modulated by the display element. The illumination optical system separately includes: an optical element of a first system configured to uniformize an intensity distribution of one of the laser lights and guide resultant laser light to the display element; and an optical element of a second system configured to uniformize an intensity distribution of another of the laser lights and guide resultant laser light to the display element.