Electronically Controlled Mechanical Watch Rate Adjustment with Rotary Switch

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Solution Overview

Problem

Existing electronically controlled mechanical watches face issues with time accuracy degradation due to fluctuations in the oscillation frequency of the crystal oscillator over time, despite adjustments using correction data, as the oscillator deteriorates, leading to reduced precision.

Innovation Solution

Incorporation of a rotary switch and logical regulation circuit that allows for digital adjustment of the clock signal cycle and oscillation frequency through a frequency divider circuit, coupled with a temperature compensation function to maintain time accuracy by correcting individual differences in the crystal oscillator's characteristics.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If correction data is stored in a logical regulation circuit at the time of product shipment, then initial time accuracy is improved, but time accuracy degrades over time due to crystal oscillator deterioration

Engineering Contradiction:
Improvetime accuracyVSAvoidtime accuracy maintenance
Core Design Contradiction:
Measurement precisionVSReliability

Solution Approach 1:

The patent transforms the static correction data stored at shipment into a dynamic adjustment system. A rotary switch enables users to select from multiple correction values (e.g., -15 to +15 seconds) stored in ROM, allowing the system to adapt to crystal oscillator deterioration over time. This dynamic adjustment mechanism maintains time accuracy by compensating for frequency drift that occurs during the watch's operational life.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent changes the parameter of correction data from a fixed single value to multiple selectable values. The logical regulation circuit stores various correction values in ROM, and the rotary switch allows selection of appropriate correction amounts based on the actual time deviation. This parameter variation enables the system to compensate for crystal oscillator frequency changes over time, maintaining time accuracy despite component deterioration.

Inventive Principle:
Principle #35Parameter changes

2Ease of operation

If a rotary switch is added for rate adjustment, then ease of operation is improved, but device complexity increases

Engineering Contradiction:
Improverate adjustmentVSAvoidcircuit structure
Core Design Contradiction:
Ease of operationVSDevice complexity

Solution Approach 1:

The patent introduces a rotary switch as an intermediary device between the user and the logical regulation circuit. This simple mechanical component allows users to select different correction values stored in ROM without requiring complex electronic interfaces or programming knowledge. The rotary switch acts as a mediator that translates user intent into electrical signals for the microcomputer, enabling easy rate adjustment while maintaining a relatively simple overall system architecture.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Manufacturing precision

If correction values are stored in ROM, then manufacturing precision is improved, but adaptability decreases

Engineering Contradiction:
Improvecorrection data storageVSAvoidpost-manufacturing adjustment
Core Design Contradiction:
Manufacturing precisionVSAdaptability or versatility

Solution Approach 1:

The patent applies preliminary action by pre-storing multiple correction values in ROM during manufacturing, rather than relying on a single correction value applied at shipment. This preliminary preparation of multiple possible correction amounts allows the system to adapt to different levels of crystal oscillator deterioration that may occur over time. The microcomputer reads the selected correction value from ROM and applies it through the logical regulation circuit, combining manufacturing precision with post-manufacturing adaptability.

Inventive Principle:
Principle #10Preliminary action

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

The solution enables precise timekeeping by allowing for easy rate adjustments in after-sales service, maintaining high accuracy over time by compensating for oscillator deterioration, and ensuring the watch remains accurate without increasing its diameter.

Implementation Method 1

a crystal oscillator 108... an oscillation circuit 111 that oscillates the crystal oscillator 108

Methodology Applied
Scientific EffectPiezoelectric effect: Piezoelectric Effect

Implementation Method 2

a generator 70 that generates electrical energy by being driven using mechanical energy

Methodology Applied
Scientific EffectElectromagnetic induction: Electromagnetic Induction

Implementation Method 3

a logical regulation circuit that stores correction data for correcting individual differences in characteristics of the crystal oscillator, and inputs a set or reset signal to each division stage of a frequency divider circuit that divides the oscillation signal of the crystal oscillator, at a predetermined timing, to digitally lengthen or shorten a cycle time of a clock signal

Methodology Applied
Scientific EffectDigital logic control:

Data Source

PatentEP4336276B1Electronically controlled mechanical watch
Publication Date: 2025.07.16 SEIKO EPSON CORP
  • EP4336276B1 patent drawingFigure 1
  • EP4336276B1 patent drawingFigure 2
  • EP4336276B1 patent drawingFigure 3

AI summary

An electronically controlled mechanical watch includes a time indication device including a time indication wheel train configured to indicate a time using a transmitted torque of a mechanical energy source, a circuit board on which a crystal oscillator, an electronic control circuit configured to adjust a rotation speed of the time indication wheel train based on an oscillation frequency of the crystal oscillator, and a plurality of logical regulation setting patterns are disposed, and a rotary switch including a conduction portion, the rotary switch being configured to rotate with respect to the circuit board to select one of the plurality of logical regulation setting patterns, conducting to the conduction portion, wherein the electronic control circuit includes an oscillation circuit, a frequency divider circuit, and a logical regulation circuit configured to control the frequency divider circuit based on a conduction state of the conduction portion and the logical regulation setting pattern.