Optical Encoding Disc Diffracting Patterns Resolution
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Solution Overview
Problem
Conventional optical encoders face challenges with resolution limitations, assembly difficulties, increased costs, and interference from environmental pollution and vibration, particularly in high-precision applications like machine tools.
Innovation Solution
An optical encoding device utilizing a light source module, encoding disc with multiple sets of diffracting patterns, and photodetectors with sensors arranged in specific configurations to enhance resolution and reduce interference, achieving higher precision through diffraction-based encoding.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conventional geometric optics is used for encoder design, then the structure is simple, but the resolution is limited and sensing interference between adjacent beams occurs
Solution Approach 1:
The patent replaces conventional geometric optics with physical optics (diffraction theory) to achieve higher resolution. By using diffracting patterns instead of traditional geometric optical elements, the system overcomes the resolution limitations of geometric optics while reducing the complexity of optical components and their alignment requirements.
Solution Approach 2:
The patent changes the fundamental optical parameter from geometric optics to physical optics by introducing diffracting patterns with specific period structures. This parameter change enables the system to achieve higher positioning resolution by utilizing diffraction effects, where the resolution is determined by the period of the diffracting patterns rather than the limitations of geometric optical systems.
2Weight of moving object
If the encoder scale is reduced for energy saving and lightweight design, then weight and energy consumption decrease, but assembly accuracy becomes more difficult and environmental interference increases
Solution Approach 1:
The patent replaces complex mechanical alignment requirements with diffraction-based optical encoding. The diffracting patterns on the encoding disc create distinct diffraction angles that can be detected without precise mechanical alignment, thereby maintaining high assembly accuracy even in reduced-scale, lightweight encoder designs.
3Volume of moving object
If the encoder scale is reduced, then the device becomes more compact, but sensitivity to environmental oil pollution and vibration increases
Solution Approach 1:
The patent substitutes mechanical contact-based sensing with non-contact optical diffraction sensing. This eliminates mechanical wear and reduces sensitivity to vibration and environmental pollution, as the diffraction pattern detection does not require mechanical contact or precise mechanical stability like conventional encoders.
4Measurement precision
If more light sensors are used to improve resolution, then positioning accuracy increases, but assembly difficulty and cost increase
Solution Approach 1:
The patent replaces the need for multiple precisely aligned light sensors with a diffraction-based system where the encoding disc's pattern structure itself generates the resolution-enhancing diffraction effects. This substitution reduces the number of sensitive components requiring precise assembly, thereby easing manufacturing while maintaining high resolution.
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 significantly enhances the resolution and assembly efficiency of optical encoders, reducing assembly costs and mitigating environmental and vibration-induced interference, enabling high-precision micro optical encoders for advanced applications.
Implementation Method 1
the plurality of first diffracting patterns of each set of first diffracting patterns enter the passing path of the source beam in sequence, so as to cause a diffraction and form a plurality of diffracted beams having different angles
Data Source
AI summary
An optical encoding device includes a light source module, an encoding disc, and a photodetector. The light source module emits a source beam. The encoding disc is disposed on a passing path of the source beam. The encoding disc has first diffracting patterns. The first diffracting patterns include a plurality of sets of first diffracting patterns arranged along a radial direction of the encoding disc. Each set of the first diffracting patterns includes a plurality kinds of first diffracting patterns having different pattern extending directions and different pattern periods. When the encoding disc is rotating, the first diffracting patterns in each set of first diffracting patterns enter the passing path of the source beam in sequence, to cause a diffraction and form diffracted beams having different angles. The photodetector receives the diffracted beams having the different angles.