Laser Light Source Coherence Reduction Homogenizer
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Solution Overview
Problem
Existing laser light source devices face challenges in preventing coherent laser-beam bundles from leaking outside, which can be harmful, and in detecting abnormalities in homogenizers that could lead to leakage, such as displacement or damage.
Innovation Solution
A laser light source device that combines multiple laser beams, uses a homogenizer to reduce coherence, and includes a photosensor system with multiple photodetectors to detect uniform light distribution, ensuring the coherence is fully removed or reduced, and automatically controls light emission based on detected abnormalities.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If a homogenizer is used to remove or reduce the coherence of laser light, then the safety of the laser light is improved, but the reliability of the system deteriorates because the homogenizer may be damaged or displaced
Solution Approach 1:
The patent introduces a feedback mechanism using a photosensor to detect the position and status of the homogenizer. The photosensor monitors the light distribution and provides feedback signals to the control unit, which adjusts the laser emission accordingly. This closed-loop system ensures that if the homogenizer is displaced or damaged, the system detects it and responds by reducing or stopping laser emission, thereby maintaining safety while improving reliability through continuous monitoring and adaptive control.
2Illumination intensity
If multiple laser beams are combined to form a laser-beam bundle, then the illumination intensity is improved, but the harmfulness of leaked light increases due to high energy density
Solution Approach 1:
The patent introduces a homogenizer as an intermediary component between the laser beam combination stage and the output. The homogenizer serves as a mediator that processes the high-energy-density coherent laser light, scattering and redistributing it to reduce coherence while maintaining illumination intensity. This intermediary device enables the system to achieve high output power without proportionally increasing the hazard of leaked coherent light, as the homogenizer transforms the light characteristics before exit.
3Reliability
If a photosensor system is added to detect homogenizer abnormalities, then the system reliability is improved, but the device complexity increases
Solution Approach 1:
The patent designs the photosensor system with multi-functionality to reduce overall complexity. The same photosensor serves multiple purposes: detecting homogenizer position, monitoring light distribution uniformity, and providing feedback for control. By making the detection system universal and integrating it with the existing laser control architecture, the patent avoids adding separate dedicated detection components for each function, thereby improving reliability through comprehensive monitoring while minimizing the increase in device complexity.
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
Effectively prevents harmful coherent laser light from leaking outside by ensuring complete coherence reduction and detects abnormalities in the homogenizer, ensuring safe operation and reliable light emission.
Implementation Method 1
a homogenizer (14) that removes or reduces the coherence of the laser-beam bundle (LB)
Implementation Method 2
a photosensor (18) that receives the incoherent laser-beam bundle (ILB) from the homogenizer (14)
Data Source
Figure 1
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Figure 3
AI summary
A laser light source device (3) and a projection display apparatus are provided. The laser light source device (3) includes a laser light source (10, 11, 12) configured to combine laser beams to emit a laser beam bundle, a homogenizer (14) configured to remove or reduce coherence of the laser beam bundle, an output optical system (20) configured to output the laser beam bundle, a beam splitter (16) configured to branch a part of the laser-beam bundle, a photosensor (18) including photodetectors configured to receive the for-detection laser-beam bundle (LS), and a light emission controller (25) configured to control light emission of the laser light source (10, 11, 12). The projection display apparatus irradiates an image displayed on an image display element (2) with illumination light from the laser light source device (3) and projects light modulated by the image upon magnifying the light by a projection optical system (4).