Segmented Light Receiver Layout for Low-Distortion Rotation Detection
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Solution Overview
Problem
Conventional rotation detectors face issues with signal distortion and unnecessary space due to slit configurations that interfere with each other, limiting the number of slits that can be disposed within a predetermined space.
Innovation Solution
A light receiving element with a specific arrangement of light receivers, where each receiver is separated into main and sub-phase portions, and disposed with gaps less than ¼ of the arrangement interval, reducing signal distortion and unnecessary space.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If two slits are disposed at an interval of 1/4 of the slit interval to receive two signals with a phase difference of 90 degrees, then the phase difference detection is achieved, but the slits interfere with each other causing signal distortion
Solution Approach 1:
Each light receiver is segmented into multiple light receiving portions (first, second, third, and fourth portions) with different widths and positions. This segmentation allows each portion to contribute differently to the signal, enabling phase difference detection while avoiding interference through careful positioning and width control of each segment.
Solution Approach 2:
Different light receiving portions have different widths (first and second portions have width of 1/3 of the arrangement interval, third and fourth portions have width of 1/6) and are positioned at specific offsets (1/12 of the arrangement interval). This local differentiation in quality allows the system to achieve both phase detection and interference avoidance.
2Area of stationary object
If the slit width is increased to 1/3 of the slit interval to reduce unnecessary space, then the space utilization is improved, but signal distortion increases due to interference between adjacent slits
Solution Approach 1:
The light receiver is divided into multiple portions with different widths and positions. By segmenting the light receiving area rather than using a single wide slit, the system achieves high space utilization while maintaining signal quality through the distributed arrangement of segments.
Solution Approach 2:
The light receiving portions are arranged not only in the arrangement direction but also offset in the perpendicular direction by 1/12 of the arrangement interval. This dimensional arrangement allows compact packing while avoiding interference.
3Reliability
If two slits are disposed at an interval larger than 1/4 of the slit interval (e.g., 5/4) to avoid interference, then signal distortion is suppressed, but unnecessary space is generated between the slits
Solution Approach 1:
Multiple light receiving portions are combined within a single light receiver structure. The first and second portions (width 1/3) and third and fourth portions (width 1/6) are integrated into one receiver unit, eliminating unnecessary gaps while maintaining signal integrity through their specific spatial arrangement.
Solution Approach 2:
By utilizing the perpendicular direction offset of 1/12 of the arrangement interval, the system achieves compact arrangement without interference, effectively using space in multiple dimensions rather than requiring large gaps in a single dimension.
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 effectively suppresses signal distortion and minimizes unnecessary space, enabling accurate detection of rotation position and direction with improved receiver density.
Implementation Method 1
a photoelectric conversion element and a slit in order to improve resolution
Data Source
AI summary
For a light receiving element, signal distortion is suppressed, and an unnecessary space is reduced. The light receiving element includes a plurality of light receiver groups (21g) arranged in an arrangement direction at a predetermined arrangement interval. Light receiver groups (21g) include first light receiver (211) and second light receiver (212). First light receiver (211) has a first main phase portion and a first sub-phase portion having a width of ⅓ of the arrangement interval. First light receiver (211) is separated into first main body portion (211a) and first separation portion (211b) each having a width in the arrangement direction of less than ¼ of the arrangement interval. Second light receiver (212) is separated into second main body portion (212a) and second separation portion (212b) each having a width in the arrangement direction of less than ¼ of the arrangement interval. First main body portion (211a) and second main body portion (212a) are arranged in the arrangement direction, and first separation portion (211b) and second separation portion (212b) are arranged in the arrangement direction.