Balanced Phosphor Wheel Layout for Stable High-Speed Rotation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The instability in the rotation of phosphor wheels due to deviation of the center of gravity from the rotation axis in existing light emitting devices, leading to malfunction of the rotation drive device and hindered high-speed rotation.
Innovation Solution
A wavelength converting composite member with a disk-shaped substrate and first and second wavelength converting members disposed in an alternating manner along the substrate's circumference, ensuring the center of gravity is aligned with the rotation axis, allowing for stable high-speed rotation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the first phosphor and second phosphor are disposed at different positions with different areas and thicknesses, then heat generation is reduced and light emission efficiency is improved, but the center of gravity deviates from the rotation axis causing unstable rotation
Solution Approach 1:
The patent applies the counterweight principle by introducing a weight member (counterweight) that is disposed on the phosphor wheel substrate to balance the center of gravity. The weight member is positioned at a location that compensates for the asymmetric distribution of the first and second phosphors, ensuring that the overall center of gravity coincides with the rotation axis. This allows the phosphor wheel to rotate stably at high speeds while maintaining the asymmetric phosphor configuration that provides superior light emission efficiency and heat dissipation.
2Productivity
If the phosphor wheel rotates at high speed, then light extraction efficiency is enhanced, but rotation stability deteriorates due to center of gravity deviation
Solution Approach 1:
The counterweight member is specifically designed to enable high-speed rotation by balancing the asymmetric phosphor distribution. The weight member's mass and position are calculated to ensure the center of gravity aligns with the rotation axis, allowing the phosphor wheel to achieve the high rotational speeds needed for enhanced light extraction efficiency without suffering from vibration or instability caused by gravitational imbalance.
3Temperature
If asymmetric phosphor configuration is used, then heat radiation effect is improved, but device complexity increases due to need for counterweight
Solution Approach 1:
The counterweight member is integrated into the phosphor wheel substrate in a straightforward manner, adding minimal structural complexity. The weight member can be disposed as a separate component or incorporated during the substrate manufacturing process, maintaining the asymmetric phosphor configuration that provides superior heat radiation while only adding a single balancing element to the overall structure.
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
Stable and high-speed rotation of the phosphor wheel is achieved, enhancing light extraction efficiency and reducing the risk of drive device malfunction.
Implementation Method 1
a first phosphor and a second phosphor which are different in a light emitting color, on the main surface 13a of the substrate 13... each phosphor region that receives light emitted from the excitation light source so as to emit wavelength-band light different from a prescribed wavelength-band emitted by the excitation light source
Data Source
Figure 1(a)~1(b)
Figure 2(a)~2(b)
Figure 3~4(b)
AI summary
Provided is a wavelength converting composite member (10) including: a disk-shaped substrate (13); a first wavelength converting member (11) provided on the substrate and containing a first phosphor that radiates fluorescence due to a parity-forbidden transition; and a second wavelength converting member (12) provided on the substrate and containing a second phosphor that radiates fluorescence due to a parity-allowed transition. The first wavelength converting member and the second wavelength converting member are disposed adjacent to each other along the circumferential direction of the substrate. The first wavelength converting member and the second wavelength converting member are provided on the substrate in such a way that the position of the center of gravity (G) of the entirety of the first wavelength converting member and the second wavelength converting member is located on the rotation axis (R) of the substrate. A light emitting device (100) is provided with the wavelength converting composite member.