Aspherical Grating Wheel Encoder Resolution
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing optical scanning light-guiding encoders face limitations in resolution due to diffraction issues and the need to increase the number of blades or the outer diameter of the grating wheel, which restricts their ability to generate distinct sequential signals effectively.
Innovation Solution
The design incorporates a light-guiding grating wheel with a gear-like structure featuring aspherical projections and an optical sensing module with offset sensing areas along horizontal lines, allowing for improved resolution without increasing the wheel's dimension or blade count, and preventing light diffraction by maintaining a constant width of the light beam through the use of aspherical surfaces.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the number of blades increases to improve resolution, then the measurement precision improves, but the outer diameter of the grating wheel increases
Solution Approach 1:
The patent transitions from spherical surfaces to aspherical projections, changing the geometric dimensionality of the light-guiding structure. This allows the light beam to maintain constant width while reducing the number of blades needed, thereby improving resolution without increasing the grating wheel's outer diameter.
Solution Approach 2:
The patent changes the geometric parameters of the light-guiding structure by using aspherical projections with specific curvature radii. The aspherical shape parameters are optimized to maintain constant light beam width, enabling higher resolution with fewer blades and a compact grating wheel design.
2Measurement precision
If the number of blades increases to improve resolution, then the measurement precision improves, but the device complexity increases
Solution Approach 1:
By changing from spherical to aspherical geometry, the patent achieves constant light beam width maintenance with fewer blades. The aspherical projections create parallel light beams that prevent diffraction, allowing high-resolution encoding with reduced blade count and simplified device structure.
Solution Approach 2:
The patent replaces the traditional spherical surface mechanical/optical system with an aspherical projection system. This substitution fundamentally changes how light is guided and encoded, enabling resolution improvement through geometric optimization rather than increasing blade quantity.
3Measurement precision
If the width of blades decreases to improve resolution, then the measurement precision improves, but light diffraction occurs
Solution Approach 1:
The transition to aspherical projections fundamentally changes the light guidance mechanism. The aspherical shape with optimized curvature radii creates parallel light beams that maintain constant width, preventing diffraction effects that occur with traditional spherical surfaces and narrow blades.
Solution Approach 2:
The patent optimizes the aspherical projection parameters, specifically the curvature radii of the aspherical surfaces, to maintain constant light beam width. This parameter optimization prevents diffraction while enabling higher resolution through reduced blade width without the harmful effects of light spreading.
4Measurement precision
If the distance between optical sensing module and light-guiding grating wheel is controlled to ensure light reception, then the measurement precision improves, but the device complexity increases
Solution Approach 1:
The patent replaces the traditional spherical surface light-guiding mechanism with aspherical projections that generate parallel light beams. This substitution eliminates the need for precise distance control between the optical sensing module and grating wheel, as the parallel beams maintain constant width regardless of distance variations, simplifying the device 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
This configuration enhances the encoder's resolution by enabling the generation of more precise sequential signals, such as [0,0], [0,1], [1,0], and [1,1], with a single aspherical projection, thereby improving signal accuracy and reducing diffraction effects.
Implementation Method 1
The light-emitting module and the optical sensing module are adjacent to the light-guiding grating wheel. An incident light generated by the light-emitting module passes through the light-guiding grating wheel for forming a parallel light or a near parallel light projected onto the optical sensing module.
Implementation Method 2
maintaining a constant width of the light beam through the use of aspherical surfaces... preventing light diffraction
Data Source
AI summary
The instant disclosure provides an optical scanning light-guiding encoder including a light-guiding grating wheel, a light-emitting module and an optical sensing module. The optical sensing module includes a plurality of sensor elements adjacent to the light-guiding grating wheel, and a plurality of exposed sensor areas of the plurality of sensor elements are offset in the transverse direction and are arranged along a plurality of different horizontal lines parallel to each other. The optical scanning light-guiding encoder provided by the instant disclosure utilizes the coordination of the light projected on the optical sensing module and the plurality of exposed sensor areas to increase the resolution thereof without increasing the size of the encoder and the number of blades thereof.