Peripheral Optical Wheel Position Detection for Thin Timepiece Mechanisms
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Solution Overview
Problem
Existing devices for detecting and synchronizing the position of wheels in electronic analogue watches are bulky and impractical for coaxial configurations, requiring vertical arrangements that increase thickness and complicate production automation.
Innovation Solution
A detection and synchronization device with a light source and light detection system arranged on the periphery of the wheel, utilizing a reflective element to direct the light beam, allowing for horizontal placement and reducing thickness, enabling automation and simplified structure.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the light source and light detection system are arranged vertically on either side of the wheel disc, then the position detection function is achieved, but the device becomes bulky and increases thickness
Solution Approach 1:
The patent transitions from a vertical arrangement (perpendicular to wheel plane) to a horizontal arrangement (within the wheel plane). The light source and detection system are positioned at the periphery of the wheel, with the light beam traveling parallel to the wheel plane through a radial hole, thereby reducing thickness while maintaining detection precision.
2Measurement precision
If two light detection devices are arranged between two coaxial wheels to detect both wheels, then position detection of both wheels is achieved, but the device becomes bulky and automation of production becomes impossible
Solution Approach 1:
The patent employs a single light source and single detection system that can detect both the first wheel and the second wheel sequentially. The system switches between detecting different wheels by timing the light emission with the rotational positions, eliminating the need for multiple detection devices and enabling automated production.
Solution Approach 2:
The patent merges the detection functions for two separate wheels into a single detection system. By using one light source and one detection system that serves both wheels alternately, the patent reduces component count and simplifies the manufacturing process while maintaining the ability to detect both wheel positions accurately.
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 reduces the bulkiness of the timepiece mechanism, allows for automated production, and increases reliability by using a single light source and detection system to synchronize both coaxial wheels, maintaining constant dimensions.
Implementation Method 1
a light source that emits a light beam and a light detection system... When the hole arrives at the level of the light source, the light beam passes through the hole and falls on the light detection system
Implementation Method 2
a first light-reflecting element projects from one of the upper or lower surfaces of the first wheel... the light beam emitted by the light source is reflected by the first reflective element in the direction of the light detection system
Data Source
AI summary
A device for detecting and synchronizing a position of at least one first wheel of a timepiece mechanism for an electronic analog wristwatch, includes this first wheel extending in a plane. The detection and synchronization device includes at least one light source emitting a light beam and at least one light detection system. A first light-reflecting element projects from one of an upper or lower surfaces of the first wheel of the timepiece mechanism. The light source and the light detection system are arranged so that in a determined position of the first wheel of the timepiece mechanism, the light beam emitted by the light source is reflected by the first light-reflecting element in the direction of the light detection system. The detection and synchronization device is housed within a case of the wristwatch.