Motor Flywheel Reflectance Shielding for Image Distortion
Solution Overview
Problem
Conventional 1-chip digital light processing projectors experience image distortion due to diffused reflection of light from metal surfaces in motor components, leading to noise in the projected image.
Innovation Solution
A motor design with a rotating portion that includes a shaft, a magnet, a rotor hub, and a flywheel, where the flywheel's outer circumferential surface has a lower reflectance than the metal surface of the rotor hub, reducing diffused reflection by shielding the metal surface with a low-reflectance material or configuration.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If a metal surface is used for the rotor hub, then manufacturing precision and strength are improved, but diffused reflection of light occurs causing image distortion
Solution Approach 1:
The patent introduces a resin layer as an intermediary substance between the light path and the metal rotor hub surface. This resin layer has low light reflectance properties, so it absorbs or diffuses incident light before it can reflect off the high-reflectance metal surface, thereby eliminating the harmful diffused reflection that causes image distortion while preserving the metal rotor hub's manufacturing precision and strength advantages
Solution Approach 2:
The patent changes the optical parameter (reflectance) of the rotor hub surface by coating it with a resin material. The resin coating transforms the high-reflectance metal surface into a low-reflectance surface, fundamentally altering how light interacts with the rotor hub without changing the underlying metal structure or its manufacturing precision
2Strength
If a metal surface with high reflectance is used, then durability and strength are improved, but image quality deteriorates due to noise from diffused reflection
Solution Approach 1:
The resin coating serves as a mediator that decouples the structural function (strength) from the optical function (reflectance). The metal rotor hub maintains its high strength through its inherent material properties, while the resin coating provides the low-reflectance optical property needed for clear image display, allowing both requirements to be satisfied simultaneously
3Ease of manufacture
If the rotor hub metal surface is exposed, then ease of manufacture is improved, but light diffused reflection causes distortion in the projected image
Solution Approach 1:
The resin coating acts as a simple intermediary layer that can be applied through conventional coating processes. This approach maintains the ease of manufacture by using standard industrial coating techniques rather than complex structural modifications, while effectively preventing light from reaching the metal surface and causing diffused reflection
Solution Approach 2:
The patent creates a composite structure combining metal (for structural integrity and ease of manufacture) and resin (for optical properties). This composite rotor hub combines the manufacturing advantages of metal with the optical advantages of resin, eliminating image distortion while preserving manufacturing simplicity
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 motor design effectively minimizes diffused reflection, ensuring accurate image display by reducing the incidence of light on high-reflectance metal surfaces and absorbing or redirecting incident light, thereby preventing image distortion.
Implementation Method 1
The outer circumferential surface of the flywheel has a reflectance lower than a reflectance of the metal surface
Data Source
AI summary
A motor includes a rotating portion, a stationary portion, and a bearing arranged to support the rotating portion such that the rotating portion is rotatable with respect to the stationary portion. The rotating portion includes a shaft arranged to extend along a central axis, a magnet, a rotor hub arranged to extend in an annular shape around the shaft, and a flywheel fixed to the rotor hub. At least a portion of an outward surface of the rotor hub is a metal surface. The metal surface is arranged radially inward of an outer circumferential surface of the flywheel. A reflectance of the outer circumferential surface of the flywheel is lower than a reflectance of the metal surface.