Reflective Lens Array Layout for Compact Projection Optics
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Solution Overview
Problem
Existing optical systems are large in size due to the use of transmissive lens array elements, which require significant space for optical paths and separate illumination and projection optical paths, making downsizing difficult.
Innovation Solution
The use of a reflective lens array element with a transmission surface and a reflecting surface, combined with an optical system that guides light in opposite directions for illumination and projection paths, and includes polarization beam splitters to change polarization states, allowing for a compact design.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If a transmissive lens array element is used, then the optical system can guide light through transmission, but the system size increases due to required optical path space
Solution Approach 1:
The patent inverts the traditional transmissive lens array approach by using a reflective lens array element. Instead of light passing through the lens array from one side to the other, light reflects off the reflective surface while maintaining the lens array's light-guiding function. This inversion reduces the optical path length and allows for a more compact system configuration where the light source and projection optical path can be integrated more closely.
2Adaptability or versatility
If separate illumination and projection optical paths are used, then each path can be optimized independently, but the overall system size increases
Solution Approach 1:
The patent merges the illumination optical path and projection optical path into a more integrated configuration. By using the reflective lens array element, the light source can be positioned closer to the projection optical path, allowing the illumination and projection functions to share common optical components and space. This merging reduces the overall system volume while maintaining the ability to independently optimize each optical path through careful design of the reflective array geometry and light source positioning.
3Volume of moving object
If the number of optical components is reduced, then the system can be downsized, but the complexity of arranging optical elements increases
Solution Approach 1:
The reflective lens array element serves multiple functions simultaneously: it acts as both the illumination optical element and the projection optical element. The same reflective surface with its array of microlenses performs both the light distribution function for illumination and the image projection function. This multi-functionality reduces the total number of optical components needed while the systematic design of the reflective array pattern provides a method to manage the arrangement complexity through regular geometric structures.
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 achieves a downsized optical system by reducing the thickness and number of optical components, enabling a more compact and flexible arrangement of optical elements while maintaining image quality.
Implementation Method 1
the lens array element being configured to reflect, at the first reflecting surface, light received from the transmission surface and emit the light from the transmission surface
Implementation Method 2
combined with an optical system that guides light in opposite directions for illumination and projection paths, and includes polarization beam splitters to change polarization states
Data Source
AI summary
An optical system includes a lens array element including a transmission surface and a first reflecting surface, the transmission surface including a lens array, the first reflecting surface facing the transmission surface, the lens array element being configured to reflect, at the first reflecting surface, light received from the transmission surface and emit the light from the transmission surface; an image display element configured to convert the received light into image light and emit the image light; a plurality of optical elements configured to guide the light emitted from the lens array element to the image display element in a first order; and an opening through which the image light converted at the image display element is emitted. The plurality of optical elements guides the image light emitted from the image display element to the opening in a second order reverse to the first order.