LED Illumination Modules for Compact Projectors
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Solution Overview
Problem
Conventional projectors using metal halide or halogen lamps are bulky and limited in size reduction due to the need for a large light guide body to mix light uniformly for the liquid crystal display, making them inefficient and costly.
Innovation Solution
The use of semiconductor light emitting diodes (LEDs) with individual primary and secondary optics to create a collimated beam for each illumination module, allowing for smaller, thinner, and more efficient projectors with adjustable power consumption based on image data.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If a large light guide body is used to mix light uniformly for the liquid crystal display, then uniform illumination is achieved, but the projector size increases and becomes bulky
Solution Approach 1:
The patent divides the illumination system into multiple independent illumination modules, each with its own light source and optical elements. Instead of using a single large light guide body to mix light from multiple sources, each module independently illuminates a specific region of the liquid crystal display panel. This segmentation eliminates the need for a bulky light guide body while maintaining uniform illumination across the display.
2Area of stationary object
If multiple separate light sources are used to illuminate the liquid crystal display, then the illumination coverage is improved, but the device complexity increases
Solution Approach 1:
The patent combines multiple light sources and their associated optical elements into integrated illumination modules. Each module merges the light source, primary collimating optic, and secondary shaping optic into a compact unit that independently illuminates a portion of the display. This merging approach increases illumination coverage while actually reducing overall device complexity compared to using completely separate components for each light source.
3Device complexity
If a shared primary optic is used for all light sources, then the device complexity is reduced, but the illumination uniformity and control flexibility deteriorate
Solution Approach 1:
The patent assigns a dedicated primary collimating optic to each light source within an illumination module. This segmentation allows each light source to be independently optimized and controlled, improving illumination uniformity and flexibility. The modular design means that while each module has its own optics, the overall system complexity is managed through standardization of the module architecture.
Solution Approach 2:
Each illumination module is designed with optical elements optimized for its specific function and position. The primary optic for each light source is tailored to produce the appropriate collimated beam for that particular module's illumination requirements. This local optimization of optical quality enables better control over illumination characteristics while maintaining manageable system complexity through modular design.
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 approach results in smaller, thinner, and less expensive projectors with improved contrast and reduced power consumption, as each illumination module can be adjusted independently to match image requirements, enhancing overall efficiency and performance.
Implementation Method 1
an optical element configured to receive light from the light source and collimate the light into a beam
Implementation Method 2
an array of Fresnel lenses disposed between the illumination modules and the liquid crystal display panel
Implementation Method 3
a reflective polarizer disposed between the illumination modules and the liquid crystal display panel
Data Source
Figure 1~2
Figure 3~5
Figure 6~7
AI summary
A projector includes a plurality of illumination modules. Each illumination module includes a light source, such as a semiconductor light emitting diode, and an optical element configured to receive light from the light source and collimate the light into a beam. Light from the illumination modules is provided to a liquid crystal display panel, then a projection lens. In some embodiments, secondary optics, such as an array of Fresnel lenses or a reflective polarizer, are disposed between the illumination modules and the liquid crystal display panel. In some embodiments, the liquid crystal display panel is a low temperature polysilicon liquid crystal display.