Lens Module Beam Expansion for Uniform Projection
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Solution Overview
Problem
Miniaturized projectors face challenges in achieving uniform light mixing due to excessively small incident angles of the illumination beam on the light integration rod, resulting in non-uniform light distribution and color distribution in projected images.
Innovation Solution
A lens module comprising a first and second lens assembly with different equivalent focal lengths is introduced, expanding the illumination beam to increase its incident angle on the light integration rod, thereby enhancing light mixing uniformity through increased reflections.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If the projector is miniaturized, then the size and weight of the projector are reduced, but the incident angle of the illumination beam on the light integration rod becomes excessively small, causing non-uniform light mixing
Solution Approach 1:
A beam expanding lens assembly is introduced as an intermediary component between the light source and the light integration rod. This assembly includes a first lens with a first focal length and a second lens with a second focal length, where the ratio of the first focal length to the second focal length is within a specific range. The beam expanding lens assembly expands the illumination beam, increasing the incident angle on the light integration rod and improving light mixing uniformity without requiring changes to the overall projector structure.
Solution Approach 2:
The patent changes the optical parameters of the illumination beam by introducing a beam expanding lens assembly with specific focal length ratios. By adjusting the focal lengths of the first and second lenses within a defined ratio range, the beam diameter and incident angle are optimized, thereby improving light mixing uniformity while maintaining the miniaturized projector structure.
2Manufacturing precision
If the beam diameter is increased to improve light mixing uniformity, then the incident angle on the light integration rod increases, but the optical path length and device complexity increase
Solution Approach 1:
The beam expanding lens assembly serves multiple functions: it expands the beam diameter, increases the incident angle on the light integration rod, and maintains a compact optical path. By integrating these functions into a single lens assembly with two lenses, the patent avoids adding multiple separate components, thereby reducing overall device complexity while achieving improved light mixing uniformity.
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 solution results in a projection device that provides a projection image with uniform color distribution by expanding the beam diameter and increasing the number of reflections within the light integration rod, improving light mixing uniformity.
Implementation Method 1
The lens module includes a first lens assembly and a second lens assembly with different equivalent focal lengths to expand the illumination beam
Implementation Method 2
the illumination beam enters a light integration rod and is reflected several times in the light integration rod to achieve light uniformity
Data Source
AI summary
The invention provides a lens module. The lens module is disposed on a transmission path of a beam to expand the beam. The lens module includes a first lens assembly and a second lens assembly. The first lens assembly is disposed on the transmission path of the beam, and the first lens assembly has a first equivalent focal length. The second lens assembly is disposed on the transmission path of the beam from the first lens assembly, and the second lens assembly has a second equivalent focal length. The second equivalent focal length is greater than or equal to the first equivalent focal length. The invention also provides a projection device including the lens module. The lens module and the projection device of the invention can provide a projection image with uniform color distribution.