Multicolor Illumination Device Using Moving Wavelength Conversion Plate
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Solution Overview
Problem
Current multicolor illumination devices using wavelength conversion methods face inefficiencies due to the lower reliability and efficiency of red phosphor materials, which are necessary for generating red light, and often result in undesirable mixing of colors at the boundaries of rotating segments.
Innovation Solution
A multicolor illumination device employing two light sources, where a blue or UV light source is used for excitation and a red light source is used directly for illumination, with a dichroic filter or optical elements to control the on/off periods of the light sources synchronized with the movement of a wavelength conversion element to prevent simultaneous output of lights from both sources, ensuring non-overlapping time periods for each color output.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If red phosphor materials are used for wavelength conversion to generate red light, then red light can be produced, but the reliability and efficiency are lower
Solution Approach 1:
The patent extracts the red light generation function from the wavelength conversion process by removing red phosphor materials. Instead of using blue/UV light + red phosphor, the system directly employs red LEDs as a separate light source, eliminating the unreliable red phosphor conversion path while maintaining red light output capability.
Solution Approach 2:
The patent changes the fundamental parameter of red light generation from wavelength conversion (blue/UV excitation + red phosphor) to direct emission (red LED). This parameter change transforms the unreliable phosphor-based approach into a reliable direct LED approach, improving both efficiency and reliability.
2Adaptability or versatility
If multiple light sources are used simultaneously, then more colors can be produced, but color mixing occurs at the boundaries of rotating segments
Solution Approach 1:
The patent implements periodic action by sequentially activating different light sources (blue/UV and red LEDs) based on the rotational position of the wavelength conversion element. The control system periodically switches between light sources to match the rotation cycle, ensuring that only one light source is active at any given time, thus preventing color mixing at segment boundaries.
Solution Approach 2:
The patent applies preliminary action by pre-synchronizing the light source activation with the rotational position of the wavelength conversion element. Before the rotating element reaches a segment boundary, the control system anticipates the position change and switches the active light source accordingly, preventing color mixing before it can occur.
3Device complexity
If a single light source with wavelength conversion is used, then the device structure is simpler, but the brightness and efficiency are reduced
Solution Approach 1:
The patent segments the illumination system into two independent light source modules (blue/UV LED and red LED) that can be selectively activated. This segmentation allows each light source to operate at optimal brightness levels without being constrained by wavelength conversion efficiency, thereby increasing overall illumination intensity while maintaining manageable device 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 eliminates the need for inefficient red phosphors, reduces color mixing issues, and allows for high-brightness, stable production of multiple colors by using readily available red LEDs, enhancing the reliability and efficiency of the illumination system.
Implementation Method 1
wavelength conversion materials such as phosphors or quantum dots can produce high brightness light at wavelengths different from the wavelength of the excitation light. In conventional devices, excitation light impinges on a wavelength conversion material, which absorbs the excitation light and emits light (the converted light) at a wavelength higher than the wavelength of the excitation light
Implementation Method 2
a dichroic filter or optical elements to control the on/off periods of the light sources synchronized with the movement of a wavelength conversion element
Data Source
AI summary
A multicolor illumination device uses a blue or UV light source to excite wavelength conversion materials and a red light source as a direct illumination light. The lights from the two light sources are combined onto a moving wavelength conversion element. The moving wavelength conversion element includes multiple segments alternatingly disposed in the paths of the incident lights, including a first segment with no wavelength conversion material, and other segments which may carry blue, green and/or yellow wavelength conversion materials. A control system controls the on/off of the two light sources so that when the first segment is in the light path, the red light source is on and the blue/UV light source is off, and vice versa when the other segments are in the light path. Alternatively, dichroic filters may be fixedly provided on the segments of the wavelength conversion element to block the blue/UV or red light.