Projector Light Modulator Merging for Cost Reduction
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Solution Overview
Problem
The high cost and size requirements of traditional projectors due to the need for three light modulators for red, green, and blue light modulation, which increases the cost and complexity.
Innovation Solution
A projector configuration using two light modulators to separately modulate four light sources (red, green, and blue) by controlling their emission periods and polarization, reducing the need for three modulators and allowing for efficient light combination using a dichroic layer.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If three light modulators are used to modulate red, green, and blue light separately, then the image quality and color accuracy are improved, but the cost and device complexity increase
Solution Approach 1:
The patent combines the modulation functions for red, green, and blue light into two light modulators. Specifically, one light modulator handles red and green light, while another handles green and blue light, thereby merging the traditionally separate modulation functions and reducing the total number of modulators from three to two.
Solution Approach 2:
Each light modulator is designed to handle multiple wavelengths of light simultaneously. The first light modulator modulates both red and green light, while the second light modulator modulates both green and blue light, making each modulator multi-functional rather than dedicated to a single color.
2Measurement precision
If three light modulators are used for red, green, and blue light modulation, then the color accuracy is improved, but the device size increases
Solution Approach 1:
The patent merges the spatial arrangement of three separate modulators into a compact two-modulator configuration. By combining the optical paths and using a dichroic mirror to merge light fluxes, the overall device footprint is reduced while maintaining the necessary color separation and modulation capabilities.
3Device complexity
If four light sources are used with two light modulators, then the cost is reduced, but the light modulation control complexity increases
Solution Approach 1:
The patent employs periodic action by controlling the four light sources to emit light in alternating periods. During a first period, the first and third light sources emit light while the second and fourth are off; during a second period, the second and fourth light sources emit light while the first and third are off. This temporal separation simplifies the modulation control despite having four light sources.
Solution Approach 2:
The system dynamically switches between different light source combinations and modulation modes depending on the period. The light modulators and light sources are dynamically controlled to achieve the desired color output while maintaining simplified control logic through the periodic switching scheme.
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 reduces costs and size while maintaining high luminance and improving apparent resolution by using two light modulators to project three color light fluxes, achieving cost reduction and enhanced image quality.
Implementation Method 1
a first light modulator that modulates the first light and the second light and outputs the modulated light fluxes as first polarized light, a third light source that emits third light having a wavelength shorter than the wavelength of the first light, a fourth light source that emits fourth light having a wavelength shorter than the wavelength of the third light, a second light modulator that modulates the third light and the fourth light and outputs the modulated light fluxes as second polarized light
Implementation Method 2
a dichroic layer that transmits the first polarized light and reflects the second polarized light
Implementation Method 3
a projection lens that projects the combined light fluxes on a screen
Data Source
AI summary
Two light modulators, a first light modulator and a second light modulator, suffice for four light sources, a first light source, a second light source, a third light source, and a fourth light source, whereby the cost can be lowered as compared with a configuration in which three light modulators are required. As a result, cost reduction is achieved. Further, since two light modulators suffice, the size of the projector can be reduced as compared with the configuration in which three light modulators are required.