Laser Projector Dual Diffusing Sections Speckle Noise Suppression
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Solution Overview
Problem
Laser projectors face challenges in suppressing speckle noise due to coherent light, which degrades display quality, and existing solutions like large light distribution angles or optical systems fail to adequately address this issue.
Innovation Solution
A projector design that includes a light source emitting laser light, a first diffusing section, and a light modulation device with a second diffusing section that diffuses the light to achieve consecutive diffusion intensity distribution, reducing speckle noise by maintaining uniform angular distribution on the screen.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If a large light distribution angle is used to suppress speckle noise, then display quality improves, but the angular distribution becomes ununiform and speckles are still noticeable
Solution Approach 1:
The patent divides the diffusion function into two separate sections: a first diffusing section that provides a large light distribution angle, and a second diffusing section that uniformizes the angular distribution. This segmentation allows each section to specialize in one function, resolving the contradiction between achieving large distribution angle and maintaining uniformity.
Solution Approach 2:
The second diffusing section acts as an intermediary between the first diffusing section and the screen. It receives the light with large distribution angle from the first section and modifies its angular distribution to be consecutive and uniform before reaching the screen, thereby suppressing speckles while maintaining uniformity.
2Stability of the object's composition
If a fly-eye optical system or rod optical system is installed to uniformize light intensity distribution, then intensity uniformity improves, but the angular distribution remains discrete and speckles are generated
Solution Approach 1:
The patent separates the functions of intensity uniformization and angular distribution control into different sections. The first diffusing section handles intensity uniformization with a large distribution angle, while the second diffusing section specifically addresses angular distribution to make it consecutive, preventing speckle formation.
Solution Approach 2:
The patent changes the parameter of angular distribution from discrete (as produced by fly-eye or rod optical systems) to consecutive through the second diffusing section. This parameter change is crucial for suppressing speckles while maintaining the intensity uniformity already achieved.
3Reliability
If laser light is used as a light source, then color reproducibility and lifespan improve, but coherent light causes speckle interference
Solution Approach 1:
The two diffusing sections together act as an intermediary system between the laser light source and the screen. They transform the coherent laser light into incoherent-like light with consecutive angular distribution, eliminating speckle interference while preserving the advantages of laser light sources.
Solution Approach 2:
The patent changes the coherence parameter of the light by introducing two diffusing sections. The first section creates a large distribution angle, and the second section makes the angular distribution consecutive, effectively transforming coherent laser light into light that behaves like incoherent light for speckle suppression.
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 design effectively suppresses speckle noise by ensuring the light intensity distribution is consecutive and flat-top, improving projection image quality and simplifying the assembly process while maintaining high light usage efficiency.
Implementation Method 1
a first diffusing section which diffuses the laser light emitted from the light source to emit a first diffused light
Implementation Method 2
a light modulation device which modulates the first diffused light emitted from the first diffusing section. Here, the light modulation device includes a second diffusing section which diffuses the first diffused light emitted from the first diffusing section to emit a second diffused light
Implementation Method 3
a light modulation device which modulates the first diffused light emitted from the first diffusing section
Data Source
AI summary
A projector includes: a light source which emits laser light; a first diffusing section which diffuses the laser light emitted from the light source to emit a first diffused light; and a light modulation device which modulates the first diffused light emitted from the first diffusing section. The light modulation device includes a second diffusing section which diffuses the first diffused light emitted from the first diffusing section to emit a second diffused light, and diffusion intensity distribution of the second diffused light emitted from the second diffusing section is distribution which is consecutive around a central axis of the second diffused light.