Concentric Light Receiver Layout for Accurate Rotation Detection

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Solution Overview

Problem

Existing rotation detectors face limitations in designing increment light receivers due to low degree of freedom, particularly when increment detectors are positioned on the inner diameter side relative to the absolute detector, leading to potential distortion in detection signals.

Innovation Solution

The design includes a light receiving element with multiple concentrically arranged light receivers, where increment detectors are positioned on the outer diameter side of absolute detectors, allowing for increased design freedom and reducing signal distortion by ensuring non-overlapping arrangements and optimized light reception.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Volume of moving object

If increment detectors are disposed on the inner diameter side relative to the absolute detector, then the structure is more compact, but the degree of freedom in designing increment light receivers is reduced

Engineering Contradiction:

Improvestructural compactnessVSAvoiddesign degree of freedom

Core Design Contradiction:

Volume of moving objectVSAdaptability or versatility

Solution Approach 1:

The patent inverts the conventional arrangement by placing increment detectors on the outer diameter side rather than the inner diameter side. This inversion resolves the contradiction by providing sufficient radial space for increment light receivers while maintaining structural compactness through optimized circumferential positioning.

Inventive Principle:

Principle #13The other way round (Inversion)

Solution Approach 2:

The patent transitions from radial space utilization to circumferential space utilization. By arranging increment light receivers along the circumferential direction rather than relying on radial depth, the design achieves both compactness and design freedom through dimensional reconfiguration.

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

2Adaptability or versatility

If the dimension in the circumferential direction of increment detectors is increased, then the degree of freedom in designing increment light receivers is enhanced, but the area occupied by the light receiving element increases

Engineering Contradiction:

Improvedesign degree of freedomVSAvoidlight receiving element area

Core Design Contradiction:

Adaptability or versatilityVSArea of stationary object

Solution Approach 1:

The patent applies local quality by concentrating increment light receivers in specific circumferential zones rather than uniformly distributing them. This allows enhanced design freedom in critical areas while minimizing the total area occupied by the light receiving element.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The light receiving element is designed to serve multiple functions: absolute position detection, incremental position detection, and rotational speed detection. By integrating these functions into a single multi-functional component, the patent avoids the need for separate dedicated areas for each function, thus reducing overall area while maintaining design freedom.

Inventive Principle:

Principle #6Universality (Multi-functionality)

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 design flexibility of increment light receivers, improves detection accuracy, and reduces signal distortion, thereby providing a more precise rotational position detection.

Implementation Method 1

a rotating plate that is irradiated with the light and rotates about a rotary shaft, in which the light is emitted to the light receiving element via the rotating plate

Methodology Applied

Scientific EffectReflection: Reflection

Implementation Method 2

a plurality of first absolute light receivers that are arranged on a first circumference and output a detection signal according to an absolute method; and a plurality of light receiver groups that output a detection signal according to an increment method

Methodology Applied

Scientific EffectPhotoelectric Effect: Photoelectric Effect

Data Source

PatentUS12601615B2Light receiving element, and rotation detector

Publication Date: 2026.04.14 PANASONIC INTELLECTUAL PROPERTY MANAGEMENT CO LTD

AI summary

Provided are a light receiving element and a rotation detector capable of enhancing a degree of freedom in designing an increment light receiver. Light receiving element includes a plurality of first absolute light receivers that are arranged on a first circumference having a first radius and output detection signals according to the absolute method, and a plurality of light receiver groups that output detection signals according to the increment method. The plurality of light receiver groups are selectively arranged in the region having the radius greater than the first circumference with respect to the plurality of first absolute light receivers, and are arranged on the second circumference concentric with the first circumference and having the second radius greater than the first radius, and the plurality of first absolute light receivers and the plurality of light receiver groups do not overlap each other.