Matrix Light-Receiving Unit for Accurate Reference Signal Generation
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Solution Overview
Problem
Existing methods for generating reference signals in incremental encoders face challenges in accuracy due to directional dependencies of reference signal edges, require complex configurations, and are hindered by diffraction effects when miniaturizing reference point detection patterns, leading to difficulties in effectively reading the patterns.
Innovation Solution
A reference signal generation apparatus using a light-receiving unit with first to fifth elements aligned in a specific direction, generating a reference signal based on the alignment and widths of these elements, allowing for a constant-width signal generation without additional optical components and minimizing diffraction effects.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the reference point detection pattern is miniaturized to improve accuracy of a reference signal, then measurement precision is improved, but diffraction effect becomes stronger making it difficult to effectively read the pattern
Solution Approach 1:
The patent transitions from one-dimensional linear arrangement of light-receiving elements to a two-dimensional matrix arrangement (5 rows × 5 columns = 25 elements). This dimensional expansion allows the system to read reference point detection patterns from multiple spatial perspectives simultaneously, effectively suppressing diffraction effects that occur when miniaturizing the pattern while maintaining high measurement precision.
2Measurement precision
If a plurality of reference point detection patterns are provided to generate accurate reference signal, then measurement precision is improved, but optical system and other components are added making configuration complicated
Solution Approach 1:
The patent merges the functions of reading multiple reference point detection patterns into a single matrix-type light-receiving unit. By arranging 25 light-receiving elements in a matrix configuration, the system can simultaneously capture information from multiple patterns that would otherwise require separate reading mechanisms, thereby improving reference signal accuracy while keeping the overall configuration simple and integrated.
3Device complexity
If reference signal is generated based on one edge of the reference point detection pattern, then device complexity is reduced, but timing of reference signal changes according to reading direction reducing accuracy
Solution Approach 1:
The matrix-type light-receiving unit with 25 elements provides universal reading capability that works independently of reading direction. The two-dimensional arrangement allows the system to accurately determine reference signal timing whether reading from left-to-right, right-to-left, top-to-bottom, or bottom-to-top, eliminating the directional dependency problem while maintaining configuration simplicity through the integrated matrix 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 approach enables the generation of highly accurate reference signals with a simple configuration, maintaining signal width consistency and reducing fluctuations even when foreign objects are present, without the need for complex optical systems.
Implementation Method 1
a reference point detection light-receiving unit that receives light from a reference point detection pattern, in which the light is emitted from a light source
Data Source
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AI summary
A reference point detection light-receiving unit receives light from a reference point detection pattern by first to fifth light-receiving elements. The first to fifth light-receiving elements are arranged in a first direction and outputs first to fifth signals, respectively. A reference signal generation circuit outputs a reference signal that starts at a period where a level of a signal, which is obtained by adding first and second signals, and a level of a signal, which is obtained by adding third and fourth signals, will become equal, and ends at a period where a level of a signal, which is obtained by adding the second and third signals, and a level of a signal, which is obtained by adding fourth and fifth signals, become equal.