Projection Illumination System Speckle Reduction
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Solution Overview
Problem
Conventional illumination systems for projection apparatuses face challenges in reducing volume and cost due to the need for multiple lenses and color wheels, which lead to speckle phenomena and increased complexity, resulting in high costs and reduced optical imaging quality.
Innovation Solution
The system incorporates a composite unit with a diffusion surface and optical surface, actuated to move perpendicular to its plane, which reduces speckle phenomena without requiring a color wheel, thereby improving optical quality and minimizing system volume and cost.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If multiple lenses and color wheels are used to expand the light source, then the beam angle matches the yellow green light and image uniformity is provided, but the system volume increases and cost increases
Solution Approach 1:
The patent combines the functions of beam expansion and color separation into a single optical system. The first light source generates blue light that passes through a first color separation component to generate cyan and blue light beams, while the second light source generates yellow-green light that passes through a second color separation component. This merging of functions eliminates the need for separate beam expansion lenses and multiple color wheels, reducing system volume while maintaining image uniformity.
Solution Approach 2:
The color separation components serve multiple functions: they act as beam expanders and simultaneously separate different wavelengths of light. The first color separation component processes blue light to generate cyan and blue beams, while the second color separation component processes yellow-green light. This multi-functionality reduces the number of components needed, thereby reducing system volume and cost.
2Illumination intensity
If laser diode is used as light source, then brightness and color saturation are improved, but speckle phenomenon occurs reducing optical imaging quality
Solution Approach 1:
The patent uses two separate light sources instead of one laser diode: a first light source generating blue light and a second light source generating yellow-green light. This segmentation of the light source function reduces the speckle phenomenon associated with laser diodes while maintaining brightness and color saturation. The blue light and yellow-green light are processed separately through their respective color separation components and then combined.
3Object-affected harmful factors
If diffuser or diffusion structure is added to alleviate speckle phenomenon, then optical imaging quality is improved, but system volume increases and cost increases
Solution Approach 1:
The patent merges the speckle reduction function into the existing color separation components. The color separation components not only separate wavelengths but also inherently reduce speckle phenomena through their optical design. This eliminates the need for separate diffusers or diffusion structures, maintaining optical imaging quality while avoiding increased system volume and complexity.
4Adaptability or versatility
If more than two color wheels are configured, then more colors can be generated, then heat dissipation and noise problems occur
Solution Approach 1:
The patent extracts the color generation function from multiple rotating color wheels and replaces it with a combination of laser diodes and color separation components. The first light source generates blue light that is split into cyan and blue beams, while the second light source generates yellow-green light. This extraction of the color generation mechanism eliminates the need for multiple color wheels, reducing heat dissipation and noise while maintaining color versatility.
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 speckle phenomena and enhances optical quality while reducing the system's volume and cost by eliminating the need for additional components like color wheels, resulting in a more efficient and cost-effective illumination system.
Implementation Method 1
the composite unit includes a diffusion surface and an optical surface opposite to each other... configured to enable the at least one light beam to pass through
Data Source
AI summary
An illumination system is configured to provide an illumination beam. The illumination system includes at least one light source, a composite unit and an actuator. The at least one light source is configured to provide at least one light beam. The composite unit includes a diffusion surface and an optical surface opposite to each other, wherein the composite unit is disposed on a transmission path of the at least one light beam and configured to enable the at least one light beam to pass through. The actuator is connected to the composite unit for driving the composite unit to move along at least one direction, and the at least one direction is perpendicular to a normal direction of a plane on which the composite unit is located. A projection apparatus including the illumination system is also provided.