Projector Illumination Optics for Tolerance-Robust Color Beam Alignment
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The issue of positioning tolerance becomes prominent in miniaturized projectors using laser diode light sources, increasing product cost due to precision machining processes, while maintaining optical efficiency and color uniformity.
Innovation Solution
An illumination system with a light source module, light splitting and combining element, beam expanding and collimating module, and light combining module, which aligns and collimates color beams to compensate for positioning tolerance, enhancing optical efficiency and color uniformity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If the projector is miniaturized by reducing the size of optical elements and using packaged miniaturized light sources, then the volume and weight of the projector are reduced, but the positioning tolerance of optical elements becomes more prominent and product cost increases due to precision machining processes
Solution Approach 1:
The optical system is divided into multiple independent modules: light source module, beam expanding and collimating module, light splitting and combining module, and light combining module. Each module can be independently positioned and adjusted, which reduces the cumulative effect of positioning errors and allows for modular assembly with relaxed tolerance requirements.
Solution Approach 2:
A beam expanding and collimating module is introduced as an intermediary between the light source and the light splitting/combining modules. This intermediary module expands and collimates the laser beams, which reduces the impact of positioning errors on the overall optical path and improves the robustness of the system against manufacturing tolerances.
2Manufacturing precision
If precision machining processes are used to reduce positioning tolerance, then the optical path accuracy is improved, but the product cost increases
Solution Approach 1:
The system incorporates adjustable and movable components that allow for dynamic alignment and compensation of positioning errors during assembly and operation. This dynamic adjustment capability enables the system to achieve high optical path accuracy without requiring extremely tight manufacturing tolerances, thereby reducing production costs.
Solution Approach 2:
The beam expanding and collimating module changes the parameters of the light beams (expansion and collimation), which makes the optical system less sensitive to positioning errors. By changing the beam parameters, the system achieves better tolerance to manufacturing variations without requiring costly precision machining.
3Volume of moving object
If the size of optical elements is reduced for miniaturization, then the projector becomes more compact, but the impact of positioning errors on optical efficiency and color uniformity increases
Solution Approach 1:
The beam expanding and collimating module performs preliminary action by expanding and collimating the laser beams before they enter the light splitting and combining modules. This preliminary collimation reduces the divergence of beams, which minimizes the impact of subsequent positioning errors on optical efficiency and color uniformity, even in a compact configuration.
Solution Approach 2:
The light splitting and combining module is designed to handle multiple color beams (red, green, blue) simultaneously with a unified optical path design. This multi-functional design ensures that all color channels benefit from the same beam expansion and collimation, maintaining color uniformity while keeping the system compact.
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 system improves optical efficiency and reduces the impact of mechanical tolerance on the optical path, leading to better yield and uniformity in projection devices.
Implementation Method 1
After the first color beam and the second color beam are transmitted to the light splitting and combining element, the first color beam and the second color beam are reflected by the light splitting and combining element
Implementation Method 2
The first color beam and the second color beam from the light splitting and combining element are expanded and collimated by the beam expanding and collimating module
Implementation Method 3
The third color beam from the light source module is reflected by the reflecting element and transmitted to the light combining module
Data Source
Figure 1A
Figure 1B
Figure 2A
AI summary
An illumination system providing an illumination beam includes a light source module generating first to third color beams, a light splitting and combining element, a beam expanding and collimating module, a reflecting element, and a light combining module. the first and second color beams are reflected by the light splitting and combining element after being transmitted to the light splitting and combining element. Transmission paths of the first and second color beams leaving the light splitting and combining element are coincident. The first and second color beams from the light splitting and combining element are expanded and collimated by the beam expanding and collimating module and transmitted to the light combining module. The third color beam is reflected by the reflecting element and transmitted to the light combining module. The transmission paths of the first to third color beams after leaving the light combining module are coincident. A projection device is provided.