Electronic Watch Position Circuit for High Speed Hand Correction

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Solution Overview

Problem

Existing electronic watches face challenges in accurately determining the date when the hour hand moves at high speed during time difference correction, leading to potential errors due to the low operation speed of microcomputers and increased workload, which can result in erroneous date updates.

Innovation Solution

The implementation of a position information circuit that automatically acquires the start and stop positions of the hour hand, allowing the CPU to process date indicator driving even when stopped, reducing CPU load and enabling efficient operation by allocating tasks during high-speed hand movement.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If the microcomputer operates at high speed to detect the detection pattern during time difference correction, then the detection accuracy improves, but the power consumption increases and other processing cannot be executed

Engineering Contradiction:
Improvedetection pattern detection accuracyVSAvoidmicrocomputer power consumption
Core Design Contradiction:
Measurement precisionVSUse of energy by moving object

Solution Approach 1:

The detection pattern is detected and stored in advance during normal operation when the microcomputer is fully operational. During time difference correction, the pre-detected pattern is compared with current position data without requiring high-speed continuous detection, thus reducing power consumption while maintaining detection accuracy.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The microcomputer operates at different speeds depending on the operational mode: full speed during normal operation for accurate detection pattern acquisition, and reduced speed during time difference correction when comparing patterns, thus adapting power consumption to actual processing needs.

Inventive Principle:
Principle #15Dynamics

2Measurement precision

If the microcomputer processes detection pattern data at high speed during time difference correction, then the date update accuracy improves, but the CPU becomes busy and cannot perform other processing

Engineering Contradiction:
Improvedate update accuracyVSAvoidCPU processing capacity for other tasks
Core Design Contradiction:
Measurement precisionVSProductivity

Solution Approach 1:

The processing tasks are segmented into different operational phases: detection pattern acquisition during normal operation, and pattern comparison during time difference correction. This segmentation allows the CPU to handle different types of processing at appropriate times, maintaining date update accuracy while freeing capacity for other tasks during correction operations.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The detection pattern is acquired and prepared in advance during normal operation when the CPU has full capacity. During time difference correction, only the comparison operation is performed using the pre-acquired pattern, reducing the computational burden and allowing the CPU to perform other necessary processing simultaneously.

Inventive Principle:
Principle #10Preliminary action

3Measurement precision

If the hand mounting position is set with high accuracy at the 12 o'clock position, then the 24-hour determination accuracy improves, but the hand mounting work requires advanced skills and long work time

Engineering Contradiction:
Improve24-hour determination accuracyVSAvoidhand mounting work efficiency
Core Design Contradiction:
Measurement precisionVSEase of manufacture

Solution Approach 1:

The mechanical requirement for precise hand mounting at the 12 o'clock position is replaced with an electronic detection system. The detection pattern and position information circuit electronically determine the 24-hour position based on hand movement rather than relying on precise mechanical alignment during assembly, thus maintaining accuracy while simplifying manufacturing.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The system changes from relying on a fixed mechanical parameter (hand mounting position at 12 o'clock) to using dynamic detection parameters (detection pattern changes during hand rotation). This allows accurate 24-hour determination regardless of the exact mechanical mounting position, greatly easing manufacturing requirements.

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentEP2711783B1Electronic watch
Publication Date: 2020.07.29 CITIZEN WATCH CO LTD
  • EP2711783B1 patent drawingFigure 1A~1B
  • EP2711783B1 patent drawingFigure 2~3
  • EP2711783B1 patent drawingFigure 4

AI summary

Provided is an electronic watch capable of surely acquiring a movement start position and a stop position of a hand when the hand moves at high speed such as a case of manual correction by a winding stem or the like, while reducing a load on a CPU. The electronic watch includes: a decode circuit for outputting data corresponding to regions acquired by segmenting a movement range of the hand; and a position information circuit for automatically acquiring region data corresponding to the movement start position of the hand and region data corresponding to the stop position thereof and sending a notification to the CPU when acquiring both the data. In this manner, the CPU can stop until the acquisition of both the data, thereby reducing the load on the CPU.