Rotation Switch Anti-Magnetic Shield Plate for Wristwatch Sensor
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional electronic wristwatches face issues with increased device size due to larger magnets for enhanced magnetic sensor sensitivity, leading to malfunctions from external magnetic field interference.
Innovation Solution
The implementation of an anti-magnetic shield plate surrounding the magnetic sensor, which absorbs external magnetic fields, allowing for high sensitivity detection of the rotating magnet's field without increasing device thickness, and using a smaller magnet design.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the magnet is designed larger to increase magnetic sensor sensitivity, then the sensitivity is improved, but the thickness and overall device size increases
Solution Approach 1:
An anti-magnetic shield plate is introduced as an intermediary component between external magnetic fields and the magnetic sensor. This shield plate absorbs or blocks external magnetic interference, allowing the use of a smaller magnet while maintaining detection accuracy. The shield plate acts as a mediator that protects the sensing system from harmful external fields.
Solution Approach 2:
The invention changes the magnetic field environment parameters by introducing the anti-magnetic shield plate, which alters the magnetic field distribution and intensity around the sensor. This allows the system to achieve high sensitivity with a smaller magnet by modifying the magnetic field parameters through the shield rather than increasing magnet size.
2Measurement precision
If the magnet is designed larger to enhance detection accuracy, then the measurement precision is improved, but the device complexity increases
Solution Approach 1:
The anti-magnetic shield plate serves as a mediator that simplifies the overall device structure by enabling the use of a smaller magnet. Instead of requiring a large magnet to achieve sufficient signal strength, the shield plate compensates for the smaller magnet's lower field intensity by blocking external interference, thereby maintaining detection accuracy with a simpler, more compact structure.
3Measurement precision
If the magnetic sensor is placed near the magnet to improve detection, then the sensitivity is improved, but the sensor becomes susceptible to external magnetic field interference
Solution Approach 1:
The anti-magnetic shield plate is positioned between external magnetic fields and the magnetic sensor, acting as a protective intermediary. This allows the sensor to remain close to the magnet for high sensitivity while the shield plate blocks harmful external magnetic fields from reaching the sensor, thus resolving the contradiction between proximity-based sensitivity and susceptibility to interference.
Solution Approach 2:
The invention converts the potential harm of external magnetic fields into a beneficial configuration by using the anti-magnetic shield plate to create a controlled magnetic environment. The shield plate transforms the harmful external interference into a defined spatial relationship where the sensor operates in a protected zone, benefiting from both close proximity to the magnet and immunity to external fields.
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
This configuration ensures accurate detection of the magnet's rotation with high sensitivity while preventing external magnetic interference, achieving miniaturization and reducing overall wristwatch size without increasing thickness.
Implementation Method 1
an anti-magnetic shield plate surrounding the magnetic sensor, which absorbs external magnetic fields
Implementation Method 2
magnetic sensors positioned in the circumferential direction of magnets provided in the stem are provided inside the wristwatch case
Data Source
Figure 1~2
Figure 3~4
Figure 5~6
AI summary
In a rotation switch including an operating member (12) that is operable to rotate, a magnet member (14) that rotates integrally with the operating member, and a magnetic sensor (15) that is placed opposite to the magnet member, wherein the magnetic sensor (15) periphery is surrounded by a frame-shaped anti-magnetic shield plate (27, 30 and 31).