Light Source Device Spot Size Matching for Color Uniformity
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Solution Overview
Problem
Existing light source devices for projectors using semiconductor lasers suffer from color unevenness due to bleeding in the fluorescent body layer, leading to differences in light emitting regions between the fluorescent body layer and the diffusive reflector, which affects superimposing performance and image color consistency.
Innovation Solution
A light source device configuration that separates light into two beam fluxes, with a first lens unit focusing on the fluorescent body layer and a second lens unit with a longer focal length focusing on a diffusive reflector, ensuring the diffused light emitting region is larger than the fluorescent light emitting region, thereby reducing color unevenness by equalizing the light emitting areas.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If the spot size on the diffusive reflector is made equal to the spot size on the fluorescent body layer, then the light emitting regions are matched, but color unevenness occurs due to bleeding in the fluorescent body layer
Solution Approach 1:
The patent applies local quality by making the spot size on the diffusive reflector larger than the spot size on the fluorescent body layer. This local differentiation compensates for the bleeding effect in the fluorescent body layer, ensuring that the light emitting regions are properly matched without causing color unevenness. The diffusive reflector's larger spot size provides a margin that accounts for the fluorescence bleeding, thereby achieving uniform color output.
2Object-affected harmful factors
If the spot size on the diffusive reflector is made larger than the spot size on the fluorescent body layer, then color unevenness is reduced, but the light emitting region matching becomes imprecise
Solution Approach 1:
The patent applies parameter changes by optimizing the spot size ratio between the diffusive reflector and the fluorescent body layer. By setting the spot size on the diffusive reflector to be larger than that on the fluorescent body layer, the patent changes the geometric parameters to compensate for fluorescence bleeding. This parameter adjustment ensures proper matching of light emitting regions while preventing color unevenness.
3Device complexity
If the same lens focal length is used for both light beam fluxes, then the optical system is simplified, but the spot sizes cannot be differentiated to reduce color unevenness
Solution Approach 1:
The patent applies segmentation by dividing the optical system into two separate paths with different lens focal lengths. The first light beam flux uses a first lens with a specific focal length, while the second light beam flux uses a second lens with a different focal length. This segmentation allows independent optimization of spot sizes for each path, enabling the diffusive reflector spot to be larger than the fluorescent body layer spot, thereby reducing color unevenness.
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 effectively reduces color unevenness in the lighting apparatus and projector images by ensuring the light emitting regions of both the fluorescent body layer and diffusive reflector are more evenly matched, enhancing image display quality.
Implementation Method 1
fluorescence that is generated by causing remaining light from the semiconductor laser to be incident on a fluorescent body layer
Implementation Method 2
a diffused light that is generated by diffusing some of light from the semiconductor laser
Data Source
AI summary
A light source device includes a light source, a fluorescent layer, a diffusive reflector, a first lens unit, a second lens unit, and a light separating and synthesizing unit. The light separating and synthesizing unit divides light coming from the light source into a first light and a second light. The first light passes through the first lens unit to enter the fluorescent layer. The second light passes through the second lens unit to enter the diffusive reflector. The size of a spot of the second light on the diffusive reflector is greater than the size of a spot, of the first light on the fluorescent body layer.