Electronic Timepiece Crown Switch Current Reduction
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Solution Overview
Problem
Existing electronic timepieces face challenges in reducing current consumption when the crown switch is turned on, which affects battery life, especially when the timepiece is displayed with the crown pulled out, as the existing pull-down and pull-up resistors continue to consume power even in standby mode.
Innovation Solution
The integration of a one-shot pulse signal generation circuit and switches, which control the pull-down and pull-up resistors, allowing them to be intermittently driven using a reference clock signal, significantly reducing current flow when the crown is pulled out.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If pull-down and pull-up resistors are continuously connected to maintain signal line stability, then the signal line remains stable and noise-resistant, but current consumption increases and battery life decreases
Solution Approach 1:
The patent applies periodic action by intermittently connecting pull-down and pull-up resistors to the signal line based on detected crown switch states. When the crown switch is in a specific state, the resistors are connected to maintain signal stability; when not needed, they are disconnected to reduce current consumption. This periodic connection/disconnection cycle resolves the contradiction between maintaining continuous signal stability and reducing power consumption.
2Ease of operation
If the crown switch detection circuit continuously monitors the crown position, then the timepiece can respond to crown operations, but current is continuously consumed even in standby mode
Solution Approach 1:
The patent applies dynamics by making the detection circuit operational state dependent. The circuit dynamically transitions between active monitoring and standby states based on whether the crown switch is detected to be in an operational position. When the crown is pulled out to a specific position, the detection circuit becomes active; when the crown is in normal position, the circuit enters low-power standby mode, thus resolving the contradiction between continuous detection capability and power consumption.
3Adaptability or versatility
If the timepiece operates in normal mode with all circuits active, then full functionality is available, but battery life is limited to approximately two years
Solution Approach 1:
The patent applies segmentation by dividing the timepiece operation into distinct modes: normal operational mode with full functionality and standby mode with reduced functionality. The crown switch detection circuit serves as a control mechanism that segments the operational states. When the crown is pulled out, the system transitions to standby mode where non-essential circuits are powered down, thereby extending battery life while maintaining the ability to switch back to full functionality when needed.
Data Source
AI summary
An electronic timepiece includes a first switch connected to a signal line, a second switch, and a one-shot pulse signal generation circuit. The first switch is inserted into the signal line. One end of the second switch is connected to the signal line at a rear stage of the first switch, and the other end of the second switch is connected to a power source. The one-shot pulse signal generation circuit generates a one-shot pulse signal by using a reference clock signal, and the second switch is controlled by the one-shot pulse signal. The timepiece device can reduce currents flowing in a pull-down resistor or a pull-up resistor when a crown switch is turned on.