Electronic Timepiece Backlash Correction for Date Display Alignment
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Solution Overview
Problem
Electronic timepieces with date display wheels experience positional offset due to backlash, especially noticeable in big date displays, affecting the appearance and requiring adjustments that consume power and time.
Innovation Solution
The electronic timepiece employs a controller to execute specific rotation processes for both display wheels, ensuring they turn in both directions before stopping, utilizing stepper motors and wheel trains with backlash correction to maintain alignment and reduce positional deviation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the display wheel turns in the second direction (reverse direction) and stops, then the adjustment speed is improved, but the positional offset due to backlash increases
Solution Approach 1:
Before stopping the display wheel after rotation in the second direction, the system preliminarily rotates the wheel in the first direction to eliminate backlash. This preliminary action ensures that the wheel teeth are properly engaged before final positioning, preventing the positional offset that would otherwise occur when stopping after reverse rotation.
Solution Approach 2:
Instead of stopping immediately after rotation in the second direction, the system inverts the expected sequence by rotating in the first direction after the second direction rotation. This inversion of the normal stopping sequence eliminates the harmful effect of backlash while maintaining the benefit of bidirectional rotation capability.
2Device complexity
If only the drive wheel turns after the display wheel stops, then the mechanism complexity is reduced, but the display wheel position offset cannot be corrected
Solution Approach 1:
The drive wheel is designed to perform multiple functions: it not only drives the display wheel during normal operation but also serves as a correction mechanism by rotating in the first direction after second direction rotation to eliminate backlash. This multi-functionality allows position correction without adding separate correction mechanisms, maintaining structural simplicity while achieving precise alignment.
3Loss of time
If the display wheel position offset is not corrected, then the operation time is reduced, but the appearance quality of big date display deteriorates
Solution Approach 1:
The system performs self-correction of the display wheel position by automatically rotating the drive wheel in the first direction after second direction rotation. This self-service mechanism eliminates the need for manual intervention or additional correction operations, maintaining operational efficiency while ensuring the display appearance quality is preserved through automatic backlash elimination and position realignment.
Data Source
AI summary
An electronic timepiece can eliminate deviation in the information display position of two display wheels. An electronic timepiece has: a first display wheel having numerals indicating the ones digit of the date; and a second display wheel having numerals indicating the tens digit of the date. At least one of the display wheels can be turned in a first direction and a second direction. A controller, when turning the display wheel in the first direction, executes a first rotation process of turning the display wheel in the first direction and then stopping rotation of the display wheel; and when turning the display wheel in the second direction, executes a second rotation process of turning the display wheel in the second direction, then turning the display wheel in the first direction, and then stopping rotation of the display wheel.