Light Source Combiner Angle Adjustment for Crosstalk Reduction
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Solution Overview
Problem
The combination of lights with different wavelength ranges in image display devices often results in reduced utilization efficiency due to crosstalk, especially when the incident angle is large, leading to a decrease in light utilization and increased speckle noise.
Innovation Solution
A light source device with a combiner that filters and adjusts the incident angles of illumination lights in specific wavelength ranges to ensure their wavelength ranges overlap, using a dichroic mirror or similar filters to reflect and transmit lights efficiently, thereby reducing crosstalk and speckle noise.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Area of moving object
If a dichroic mirror is designed to have a wide wavelength range to accommodate blue shift at large incident angles, then the combiner can handle large incident angles, but crosstalk between light in narrow wavelength range and light in wide wavelength range increases, reducing light utilization efficiency
Solution Approach 1:
The patent applies dynamics by making the incident angle adjustable rather than fixed. The illumination optical system is designed to dynamically adjust the incident angle of light entering the combiner, allowing optimization between blue shift accommodation and crosstalk reduction based on operating conditions. This resolves the contradiction by enabling the system to adapt its incident angle to balance wavelength range coverage and light utilization efficiency.
2Reliability
If lights with different wavelength ranges are combined using a dichroic mirror, then color reproducibility is improved, but crosstalk reduces light utilization efficiency
Solution Approach 1:
The patent applies partial action by selectively combining only the necessary wavelength ranges rather than attempting to combine all wavelengths. The dichroic mirror is designed with specific transmission and reflection characteristics that allow selective combination of blue, green, and red wavelength ranges while minimizing crosstalk. This partial combination approach maintains color reproducibility while reducing unnecessary light loss from crosstalk.
3Adaptability or versatility
If the incident angle of light on the combiner is increased, then the wavelength range shifts to short wavelength side (blue shift), but the combiner needs wider wavelength range design which increases crosstalk
Solution Approach 1:
The patent applies dynamics by making the incident angle adjustable rather than fixed. The illumination optical system is designed to dynamically adjust the incident angle of light entering the combiner, allowing optimization between blue shift accommodation and crosstalk reduction based on operating conditions. This resolves the contradiction by enabling the system to adapt its incident angle to balance wavelength range coverage and light utilization efficiency.
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 enhances light combination efficiency, reduces speckle noise, and simplifies the illumination optical system configuration, improving the overall performance and manufacturability of the light source device.
Implementation Method 1
the combiner has a characteristic of filtering the first illumination light on the basis of a wavelength range and an incident angle of the first illumination light, and a characteristic of filtering the second illumination light on the basis of a wavelength range and an incident angle of the second illumination light
Implementation Method 2
using a dichroic mirror or similar filters to reflect and transmit lights efficiently
Implementation Method 3
a wavelength conversion unit that includes a phosphor material and converts a part of the emitted light in the first wavelength range into a fluorescent emission light in a different wavelength range
Data Source
AI summary
A light source device and an image display device that combine light with high efficiency are provided. The light source device includes a first light source unit, a first illumination optical system that emits a first illumination light, a second light source unit, a second illumination optical system that emits a second illumination light, and a combiner on which the first illumination light and the second illumination light are incident. The combiner filters the incident light on the basis of a wavelength range and an incident angle, and angles at which the first illumination light and the second illumination light are incident on the combiner are each adjusted in such a way that the wavelength range of the first illumination light emitted from the combiner and the wavelength range of the second illumination light emitted from the combiner approach or overlap with each other.