Encoder Phase Adjuster Circuit for Fine Multi-Phase Synchronization
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing phase adjustment techniques for photoelectric encoders, such as those described in Japanese Patent Laid-open Publications 2002-116060 and 2002-162253, can only perform rough adjustments with a 90° phase shift, leading to potential misalignment and mistaken detection of absolute values due to varying pulse widths and timing in origin point signals.
Innovation Solution
A phase adjuster comprising a resistor string and a switch portion that generates signals with a phase difference of 2π/MN, allowing for precise phase adjustments by amplifying signals between resistors connected in series, enabling phase shifts smaller than 90°, thereby improving synchronization between main and origin point signals.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If mechanical fine adjustments are made to the attachment position of the detection head, then phase synchronization between main signal and origin point signal can be achieved, but the adjustment process takes a long time due to narrow pulse width making observation difficult
Solution Approach 1:
The patent replaces mechanical fine adjustment of the detection head with an electrical phase adjustment mechanism. A phase adjuster circuit generates multiple phase-shifted versions of the main signal (0°, 45°, 90°, 135°, 180°, 225°, 270°, 315°) and selects the appropriate phase through switching control, eliminating the need for time-consuming mechanical adjustments while maintaining synchronization accuracy.
Solution Approach 2:
The patent makes the phase adjustment dynamic and selectable rather than fixed. By providing multiple phase-shifted signals and using switching control based on detection results, the system can adaptively select the optimal phase alignment, transforming a static mechanical adjustment into a dynamic electrical selection process.
2Loss of time
If rough phase adjustments with 90° pitch are performed by switching, then adjustment time is reduced compared to mechanical adjustments, but proper synchronization cannot be achieved depending on origin point signal state
Solution Approach 1:
The patent segments the phase adjustment range into multiple discrete steps (0°, 45°, 90°, 135°, 180°, 225°, 270°, 315°) rather than using a single 90° pitch. This finer segmentation allows the system to achieve precise synchronization by selecting from more granular phase options, resolving the limitation of coarse 90° adjustments.
Solution Approach 2:
The patent changes the phase parameter in discrete steps of 45° or finer across multiple stages. By providing phase-shifted signals at multiple discrete phase values and selecting the appropriate one through switching control, the system achieves both rapid adjustment and precise synchronization.
3Measurement precision
If the detection head position is mechanically adjusted, then phase shift can be corrected, but the narrow pulse width of origin point signal prevents visual observation and requires repeated trial and error
Solution Approach 1:
The patent replaces mechanical position adjustment with electrical phase shifting. The phase adjuster circuit generates multiple phase-shifted versions of the main signal, and switching control selects the appropriate phase based on detection results, eliminating the need for repeated mechanical trial-and-error adjustments.
Solution Approach 2:
The system performs self-adjustment through automatic detection and switching control. The detection device identifies the optimal phase alignment, and the switching control automatically selects the corresponding phase-shifted signal, making the adjustment process self-service rather than requiring manual mechanical adjustment.
Data Source
AI summary
A resistor string outputs sixteen signals with a phase difference of 22.5° by dividing voltage between two adjacent phases of a four-phase input signal with a phase difference of 2π/M (where M is an integer equal to or greater than 2), and by generating four signals with a delayed phase for each phase of the four-phase input signal. A switch portion selects four signals with a phase difference of 90° from the sixteen signals. Amplifiers output each of the four signals, which are attenuated by dividing the voltage with the resistor string, as a four-phase output signal by amplifying each of the four signals such that an amplitude of the four signals matches the amplitude of the four-phase input signal.