Encoder Scale Dual-Surface Magnet Configuration
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Solution Overview
Problem
Existing encoder designs face challenges in downsizing while maintaining strong magnetic field detection accuracy, as small magnets generate weak fields and large magnets increase weight and size, compromising encoder performance.
Innovation Solution
The encoder scale features a first magnet on one surface and a second magnet or magnetic yoke on the opposite surface, generating magnetic fields that are detectable by a magnetic detector, allowing for a strong magnetic field without increasing the size or weight of the encoder.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If a small magnet is used, then the encoder size is reduced, but the magnetic field strength becomes weak and difficult to detect
Solution Approach 1:
The patent transitions from a single-surface magnet arrangement to a dual-surface configuration, placing magnets on both the front and back surfaces of the scale substrate. This spatial arrangement in multiple dimensions allows the magnetic fields to interact constructively, generating a stronger combined magnetic field at the detection position without increasing the encoder's overall volume.
Solution Approach 2:
The patent combines the magnetic fields generated by multiple magnets disposed on different surfaces of the scale substrate. By strategically positioning magnets with appropriate polarities on both surfaces, the magnetic fields merge and reinforce each other, creating a stronger composite magnetic field that improves detection accuracy while maintaining a compact encoder design.
2Reliability
If a large magnet is used, then the magnetic field strength is sufficient for detection, but the encoder size and weight increase
Solution Approach 1:
The patent divides the magnetic field generation function across multiple smaller magnets distributed on both surfaces of the scale substrate, rather than using a single large magnet. This segmentation allows each individual magnet to be compact while their combined magnetic fields achieve the required strength for accurate detection, thus maintaining a small overall encoder size.
Solution Approach 2:
By utilizing both front and back surfaces of the scale substrate for magnet placement, the patent effectively uses the third dimension (depth/thickness) to distribute magnetic field sources. This allows sufficient magnetic field strength to be achieved without increasing the lateral dimensions of the encoder, keeping it compact.
3Reliability
If a large magnet is used, then the magnetic field strength is sufficient for detection, but the weight of the scale increases
Solution Approach 1:
The patent segments the magnetic field generation task across multiple smaller magnets instead of using one large heavy magnet. The total mass of multiple small magnets is significantly less than a single large magnet that would be required to produce an equivalent magnetic field, thus reducing the overall weight of the scale while maintaining detection accuracy.
Solution Approach 2:
By distributing magnets on both surfaces of the substrate, the patent reduces the volume and mass of individual magnetic components needed. The combined effect of multiple smaller magnets distributed in three-dimensional space achieves the required field strength with less total material, thereby reducing the scale's weight.
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 enables the generation of a strong magnetic field, allowing for the downsizing of the encoder scale and encoder, while maintaining detection accuracy and reducing production costs by simplifying magnetization processes.
Implementation Method 1
a second magnet or a magnetic yoke disposed on the first surface and configured to generate magnetic fields with the magnetic poles of the first magnet
Data Source
AI summary
An encoder scale S includes a substrate 10 that rotates about a rotation axis AX and has an optical pattern along a rotation direction D on a first surface 10a crossing the rotation axis AX, of the substrate 10. The scale S also includes a first magnet M1 that is disposed on a second surface 10b of the substrate 10 different from the first surface 10a and has different magnetic poles (N-pole M1n, S-pole M1s) set therein with the rotation axis AX therebetween and a second magnet M2 that is disposed on the first surface 10a and generates magnetic fields with the N-pole M1n and S-pole M1s of the first magnet M1.