Prism-Based Projector Combining Three SLMs
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Solution Overview
Problem
Conventional single modulator projectors can cause discomfort due to unwanted artifacts during color transitions, while three modulator projectors are expensive and complex due to large optics required for combining images from multiple SLMs.
Innovation Solution
A projector design utilizing a first and second prism with spatial light modulators and dichroic layers to modulate and combine red, green, and blue light efficiently, reducing the need for complex optics by using total internal reflection and dichroic layers in an X-prism to project a full color image.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a single spatial light modulator is used, then the device complexity is reduced, but color transition artifacts are generated causing discomfort
Solution Approach 1:
The invention divides the single modulator system into three separate spatial light modulators, each dedicated to a specific color (red, green, blue). This segmentation allows simultaneous projection of all three colors without temporal transitions, eliminating the color transition artifacts while maintaining manageable device complexity through modular architecture
Solution Approach 2:
The invention introduces an X-prism as an intermediary optical element that combines the light paths from three separate modulators. The X-prism with its dichroic layers acts as a mediator that merges the three color channels into a single projection path, enabling simultaneous color display without requiring complex additional optics
2Object-affected harmful factors
If three spatial light modulators are used, then color transition artifacts are eliminated, but the optics become large, complex and expensive
Solution Approach 1:
The invention merges the optical paths of three separate modulators through the X-prism structure. By combining the reflection and transmission paths within a single integrated prism component, the system achieves compact optics that are smaller and less complex than traditional three-chip projector designs
Solution Approach 2:
The X-prism serves multiple functions simultaneously: it acts as a beam combiner, a color separator, and a path integrator. This multi-functionality reduces the need for additional dedicated optical components, simplifying the overall optical system while maintaining the ability to handle three color channels independently and combine them effectively
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 design provides a compact, cost-effective solution for projecting full color images without the artifacts associated with single modulator projectors, by efficiently combining modulated light from multiple SLMs using dichroic layers and total internal reflection, resulting in a more comfortable and efficient projection system.
Implementation Method 1
a first prism having a dichroic layer to reflect light having a first color
Implementation Method 2
modulated first light that is reflected off the second surface of the second prism
Implementation Method 3
modulated second light that is reflected off the second surface of the third prism and passes through the dichroic layer of the first prism
Data Source
AI summary
Described examples include a projector including a first prism having a dichroic layer. A second prism has a first spatial light modulator on a first surface, and a first light source directed through a second surface of the second prism to the first spatial light modulator. The first spatial light modulator is operable to modulate the first light to provide modulated first light that is reflected off the second surface of the second prism and the dichroic layer to projection optics. A third prism has a second spatial light modulator on a first surface and a second light source directed through a second surface to the second spatial light modulator. The second spatial light modulator is operable to modulate the second light to provide modulated second light that is reflected off the second surface of the third prism and passes through the dichroic layer to the projection optics.