Anamorphic Prism Assembly Illuminates Spatial Light Modulators
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Solution Overview
Problem
In image projection and display systems, there is a light loss due to mismatched aspect ratios between common square light sources and rectangular spatial light modulators, leading to inefficient illumination of the modulators.
Innovation Solution
An anamorphic prism assembly is used, comprising two optical elements spatially separated by a gap, modifying the light shape to increase the collection area on the spatial light modulator, thereby enhancing light collection and image brightness.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If a square light source is used to illuminate a rectangular spatial light modulator, then the light source structure is simple and common, but there is light loss due to mismatched aspect ratios
Solution Approach 1:
The patent introduces an anamorphic prism assembly as an intermediary optical element between the square light source and rectangular spatial light modulator. This assembly includes two prisms with specific refractive indices and angles that transform the light beam shape from square to rectangular, enabling efficient illumination without direct mismatch between source and modulator aspect ratios.
Solution Approach 2:
The patent changes the optical parameters of the light beam by using prisms with specific refractive indices (n1 and n2) and apex angles (α1 and α2) to transform the beam's aspect ratio. The parameter transformation is governed by the relationship: tan(α1)/tan(α2) = (n2/n1)², which converts the square beam into a rectangular beam matching the spatial light modulator dimensions.
2Area of stationary object
If the light beam shape is transformed using an anamorphic prism assembly, then the collection area on the spatial light modulator is increased, but the optical system complexity increases
Solution Approach 1:
The patent employs asymmetric prism geometry where the two prisms have different apex angles (α1 and α2) and refractive indices (n1 and n2). This asymmetric design enables selective transformation of one dimension of the light beam while maintaining control over the other dimension, achieving rectangular beam shaping from a square source with optimized collection area.
Solution Approach 2:
The anamorphic prism assembly serves multiple functions simultaneously: it transforms the light beam aspect ratio, increases the collection area on the spatial light modulator, and can be integrated into existing projection optical systems. The prisms are designed to work with common light sources while achieving efficient illumination of rectangular modulators.
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 anamorphic prism assembly increases the collection angle and brightness of the image generated by the spatial light modulator, effectively illuminating a larger area and reducing light loss between the light source and the modulator.
Implementation Method 1
an assembly of at least two optical elements coupled between the light source and the spatial light modulator... modify the light to a second shape different from the first shape
Data Source
AI summary
According to particular embodiments, an illumination system includes a light source that generates light for use in illuminating a spatial light modulator and an assembly of two optical elements spatially separated by a gap that receives the light from the light source, changes the shape of the light, and transmits the light onto the spatial light modulator.