Ellipsoidal Reflector for Multi-Color LED Light Source
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Solution Overview
Problem
Conventional light source apparatuses for projectors, such as those used in vehicles, often prioritize either coloration or brightness of light rays, but not both effectively, leading to suboptimal performance in image projection.
Innovation Solution
A light source apparatus featuring a reflector with an inner surface complementary to an ellipsoidal shape, focusing light rays from an array of red, green, and blue LEDs at a second focal point, with a light tunnel inlet positioned at this focal point, and a time-divisional driver outputting primary-colored image signals to a spatial light modulator for synchronized color adjustment.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a white LED is used as the light source, then the device complexity is reduced, but the coloration quality deteriorates
Solution Approach 1:
The invention segments the light source into multiple LEDs emitting different colors (red, green, blue) instead of using a single white LED. Each color LED is positioned at a focal point of the ellipsoidal reflector, allowing independent control and optimization of each color component to achieve balanced coloration while maintaining relatively simple device structure.
Solution Approach 2:
The invention applies local quality by positioning different colored LEDs at specific focal points of the ellipsoidal reflector. Each focal point is optimized for a specific color wavelength, ensuring that each color component is efficiently collected and directed. This local optimization enables high coloration quality while keeping the overall device structure manageable.
2Illumination intensity
If multiple different-colored LEDs are used to achieve balanced coloration, then the coloration quality improves, but the device complexity increases
Solution Approach 1:
The ellipsoidal reflector serves multiple functions simultaneously: it collects light from each focal point, focuses light onto the light tunnel inlet, and provides structural support for mounting multiple LEDs. This multi-functionality reduces the need for additional optical components, thereby limiting the increase in device complexity while achieving balanced coloration with multiple colored LEDs.
Solution Approach 2:
The invention uses an ellipsoidal (curved) reflector geometry to efficiently collect and focus light from multiple focal points where different colored LEDs are positioned. The curved surface enables effective light collection and direction to the light tunnel inlet, achieving balanced coloration without requiring complex additional optical elements that would increase device complexity.
3Use of energy by moving object
If the light source is miniaturized to reduce power consumption, then the energy efficiency improves, but the brightness output deteriorates
Solution Approach 1:
The ellipsoidal reflector geometry efficiently collects and focuses light from miniaturized LEDs positioned at the focal points. The curved reflective surface maximizes light collection efficiency, directing more light onto the light tunnel inlet compared to flat or other geometries. This enables miniaturized LEDs to achieve sufficient brightness output while maintaining low power consumption.
Solution Approach 2:
The invention converts the limitation of miniaturized LEDs (lower individual brightness) into a benefit by using multiple colored LEDs positioned at focal points of the ellipsoidal reflector. The reflective geometry compensates for the lower individual output of each miniaturized LED, focusing their combined light efficiently onto the light tunnel inlet, thereby achieving sufficient overall brightness while maintaining energy efficiency.
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 achieves balanced coloration and brightness of light rays, enhancing the efficiency and quality of projected images by ensuring equalized spectral luminous efficiency and luminance at the light tunnel inlet.
Implementation Method 1
light rays emitted by the light emitting elements of the array are reflected by the inner surface of the reflector
Implementation Method 2
The reflector has a focal point within the inner surface thereof coinciding in position with one of the pair of focal points. An array of light emitting elements is disposed at the focal point within the inner surface of the reflector whereby light rays emitted by the light emitting elements of the array are reflected by the inner surface of the reflector so as to be focused at a point coinciding in position with the other of the pair of focal points.
Data Source
AI summary
In a light source apparatus, a reflector has an inner reflective surface complementary to a part of the outer surface of an ellipsoid with a pair of focal points. The surface part has a first one of the pair of focal points therewithin. An array of light emitting elements is disposed at the position of the first focal point within the reflective surface. Thus, light rays emitted by the array of light emitting elements are reflected by the inner surface of the reflector so as to be focused at the other of the pair of focal points.