Projector Laser Oscillation Design for Speckle Noise Reduction
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Solution Overview
Problem
Existing projectors using laser light sources with semiconductor lasers arranged in a two-dimensional manner face difficulties in sufficiently removing speckle noise due to light interference, which affects the quality of the projected image.
Innovation Solution
The projector employs a configuration with first and second laser light emitting elements having different oscillation states and drive frequencies, combined with a diffusion member and superimposition optical system to minimize speckle noise by diffusing and homogenizing light.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If multiple semiconductor lasers are arranged in a two-dimensional manner within each laser light source, then the luminance and color gamut are improved, but speckle noise increases due to light interference
Solution Approach 1:
The invention divides the laser light source into multiple independent laser units, where each unit contains one or more semiconductor lasers. These segmented laser units are arranged such that their light beams do not overlap in the spatial domain, thereby preventing interference between beams from different units while maintaining high luminance through the combined output of multiple units.
Solution Approach 2:
The invention transitions from a two-dimensional arrangement of semiconductor lasers within single light sources to a three-dimensional spatial arrangement of multiple laser units. By controlling the spatial distribution and optical paths of multiple laser units, the system achieves high luminance without beam interference, effectively moving the problem solution into the spatial dimension.
2Stability of the object's composition
If a diffusion plate is used to diffuse combined light, then the uniformity of light distribution is improved, but speckle noise cannot be sufficiently removed due to interference from multiple semiconductor lasers
Solution Approach 1:
The invention applies preliminary spatial separation and optical path control to prevent beam interference before the light reaches the diffusion plate. By ensuring that light beams from different laser units do not interfere with each other in advance, the diffusion plate can effectively uniformize light distribution without being compromised by speckle noise from interfering beams.
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 reduces speckle noise, enhancing image quality by suppressing interference between laser beams and improving luminance while maintaining a compact device configuration.
Implementation Method 1
a diffusion member on which the first light and the second light are incident
Implementation Method 2
a superimposition optical system on which light emitted from the diffusion member is incident
Data Source
AI summary
A projector of the present disclosure includes a first laser light emitting element that emits first light; a second laser light emitting element that emits second light having a same peak wavelength as the first light; a diffusion member on which the first light and the second light are incident; a superimposition optical system on which light emitted from the diffusion member is incident; a light modulation device that modulates light incident from the superimposition optical system in accordance with image information; and a projection optical device that projects light modulated by the light modulation device, wherein the first laser light emitting element and the second laser light emitting element have oscillation states different from each other.