Laser Light Source Apparatus for Compact Single-Plate Projectors
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Solution Overview
Problem
Existing projector designs that use multiple light sources and liquid crystal panels to achieve single-plate projection face challenges in reducing the size of the light source apparatus due to increased size requirements.
Innovation Solution
A light source apparatus comprising four laser light source sections with semiconductor lasers, each outputting blue, green, and red light beams, are disposed in specific imaginary planes and lines to ensure efficient polarization and alignment, eliminating the need for narrow-interval polarization converters and wavelength converters, thereby reducing the size of the apparatus.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If multiple light sources and liquid crystal panels are used to achieve single-plate projection, then image quality and brightness are improved, but the size of the light source apparatus increases
Solution Approach 1:
The patent combines multiple laser light sources (blue, green, red) into a single integrated light source apparatus with a unified optical path. The four laser light sources are disposed in an imaginary plane perpendicular to the center axis of the luminous flux, allowing them to share common optical components including a single liquid crystal panel, thereby reducing the overall apparatus size while maintaining multi-color image projection capability
Solution Approach 2:
The patent arranges the four laser light sources in a two-dimensional imaginary plane perpendicular to the optical axis, with specific geometric relationships (two pairs facing each other with the center axis sandwiched between them). This spatial arrangement in another dimension allows efficient light path integration without increasing the longitudinal size of the apparatus
2Device complexity
If narrow-interval polarization converters and wavelength converters are added to enable single-plate projection, then single-plate configuration is achieved, but device complexity increases
Solution Approach 1:
The patent extracts and eliminates the need for narrow-interval polarization converters and wavelength converters by directly using four laser light sources that naturally emit linearly polarized light with the same polarization direction. This removal of unnecessary conversion components simplifies the device while achieving single-plate projection
Solution Approach 2:
The patent uses a single liquid crystal panel to perform multiple functions: it simultaneously modulates all four color beams (blue, green, red and an additional green beam) without requiring separate panels for different wavelengths. The panel acts as a universal modulator for all color channels, reducing device complexity
3Manufacturing precision
If four laser light sources are arranged in specific imaginary planes and lines for efficient polarization alignment, then light incidence efficiency is improved, but manufacturing precision requirements increase
Solution Approach 1:
The patent employs asymmetric arrangement of the four laser light sources in the imaginary plane, with two pairs positioned to face each other across the center axis. This asymmetric yet balanced configuration optimizes the light paths to efficiently incident on the liquid crystal panel while maintaining feasible manufacturing tolerances through symmetric pairing
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 allows for efficient incidence of color beams on a single liquid crystal panel, reducing the projector's size, simplifying the light source apparatus, and enhancing image brightness without the need for additional conversion components.
Implementation Method 1
a first laser light source section that outputs first light having a first wavelength band, a second laser light source section that outputs second light having a second wavelength band different from the first wavelength band, a third laser light source section that outputs third light having the second wavelength band, and a fourth laser light source section that outputs fourth light having a third wavelength band different from the first and second wavelength bands. Each includes a semiconductor laser. The first light, the second light, the third light, and the fourth light are each linearly polarized light and have the same polarization direction.
Data Source
AI summary
Four of laser light source sections each includes a semiconductor laser. Any two of the laser light source sections are disposed in an imaginary plane perpendicular to the center axis of a luminous flux and on a first imaginary line that intersects with the center axis so as to face each other with the center axis sandwiched between the two laser light source sections, and other two of the laser light source sections are disposed on a second imaginary line perpendicular to the first imaginary line so as to face each other with the center axis sandwiched between the two laser light source sections. The laser light source sections are at the same distance from the center axis. The first light, the second light, the third light, and the fourth light are each linearly polarized light and have the same polarization direction.