Pump Laser Row Lighting Device with MEMS Mirror Scanning
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Solution Overview
Problem
Conventional lighting devices for applications like projection and endoscopy rely on rotating components and multiple axes for laser beam scanning, which are bulky, inefficient, and prone to phosphor degradation, limiting compactness and rapid color control.
Innovation Solution
A compact lighting device with a pump laser row and a movable single-axis MEMS mirror that scans a strip-shaped phosphor pattern, allowing for efficient wavelength conversion and mixed light generation without rotating components, enabling rapid color changes and uniform power density.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a rotating phosphor wheel with multiple laser beams is used, then phosphor degradation is reduced by distributing laser power over a larger surface, but the device becomes bulky and complex with rotating components
Solution Approach 1:
The phosphor surface is segmented into multiple regions with different phosphor materials (e.g., red, green, blue phosphors arranged in segments). The laser beam scans across these segmented regions in a fixed pattern, eliminating the need for rotating components while still distributing the laser power across different phosphor materials to reduce degradation.
Solution Approach 2:
Instead of using a rotating phosphor wheel, the patent employs a dynamic scanning approach where a laser beam is rapidly moved across a fixed phosphor surface using galvanometric mirrors or similar scanning mechanisms. This dynamic scanning achieves the same effect of distributing laser power over time and space without mechanical rotation.
2Reliability
If multiple laser beams are scanned over a phosphor surface using rotating components, then phosphor degradation is reduced, but the device loses compactness
Solution Approach 1:
Multiple laser beams are merged into a single scanned beam path that sequentially irradiates different phosphor regions. The scanning mechanism combines the functions of multiple lasers and rotating components into a single integrated system, achieving compactness while maintaining phosphor protection through distributed irradiation.
Solution Approach 2:
The patent replaces mechanical rotating components with optical scanning systems (e.g., galvanometric mirrors) that can be integrated into a compact form factor. This substitution maintains the ability to distribute laser power across different phosphor regions while significantly reducing the device volume.
3Volume of moving object
If a single laser beam scans a phosphor surface, then device compactness is improved, but color control speed is reduced
Solution Approach 1:
The single laser beam performs periodic scanning across the phosphor surface at high frequency. By rapidly repeating the scanning cycle and using multiple phosphor regions that can be irradiated in sequence, the system achieves fast color control through periodic irradiation patterns while maintaining compact device structure.
Solution Approach 2:
The patent transitions from spatial multiplication of laser beams to temporal multiplication through rapid scanning. By scanning the laser beam across multiple phosphor regions in rapid succession, the system achieves multi-color capability through time-multiplexed irradiation, maintaining compactness while enabling fast color control.
4Power
If laser radiation is focused on a small phosphor area, then power density is increased for efficient conversion, but phosphor stress and degradation increase
Solution Approach 1:
The patent implements continuous scanning of the laser beam across the phosphor surface, ensuring that no single area receives sustained high-power irradiation. This continuous movement distributes the thermal and mechanical stress across different phosphor regions over time, reducing localized phosphor stress and degradation while maintaining efficient power density during each instantaneous beam position.
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
The solution achieves high luminance and compactness by using a single-axis MEMS mirror to scan a strip-shaped phosphor pattern with a pump laser row, reducing phosphor stress and enabling efficient wavelength conversion for uniform light generation and rapid color control.
Implementation Method 1
The laser radiation incident on the phosphor is partially converted by the phosphor by means of wavelength conversion into a wavelength-converted useful light
Implementation Method 2
a movable mirror, which is designed to reflect the pump laser radiation of the pump laser row in a targeted manner on the phosphors in dependence on its position
Data Source
AI summary
A lighting device may include a pump laser row and a phosphor arrangement. The pump laser row is designed for the purpose of emitting pump laser radiation for the irradiation of the phosphor arrangement. The phosphor arrangement has at least two different phosphors, which can be irradiated with the pump laser radiation and emit the pump laser radiation again at least partially and converted in wavelength differently in each case, and a movable mirror, which is designed for the purpose of reflecting the pump laser radiation of the pump laser row in a targeted manner on the phosphors in dependence on its position.