Magnetic Lens Position Detection for Compact Imaging Systems
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Solution Overview
Problem
Existing lens devices face challenges in accurately detecting the position of a movable lens without moving it after power is supplied, particularly in achieving high imaging performance while maintaining a compact size and low cost, especially when dealing with slow zooming or high-resolution requirements.
Innovation Solution
A lens device comprising a movable lens, a rotating member, a first signal detection section for position changes, a second signal detection section for rotation changes, and control sections for outputting lens position information, allowing for immediate position detection without lens movement after power supply, using magnetic recording members and Hall ICs to achieve high resolving power.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a position detection device is used to detect the position of a movable lens with high accuracy, then imaging performance is improved, but the device complexity and cost increase
Solution Approach 1:
The patent replaces complex mechanical position detection mechanisms with magnetic field-based detection. Magnetic recording members with patterns are attached to the lens barrel, and magnetic sensors detect the position by sensing changes in the magnetic field pattern, eliminating the need for complex mechanical encoders or potentiometers while achieving high precision.
Solution Approach 2:
The patent uses magnetic recording members that create a magnetic field pattern copy of the lens position. Instead of directly measuring mechanical displacement, the system creates a magnetic field representation of the lens barrel position and uses sensors to read this magnetic pattern, simplifying the detection mechanism while maintaining accuracy.
2Volume of moving object
If the lens device is designed to be compact, then the device size is reduced, but the position detection precision deteriorates
Solution Approach 1:
The patent transitions from one-dimensional mechanical displacement measurement to two-dimensional magnetic field pattern detection. By attaching magnetic recording members with spatial patterns to the lens barrel and using magnetic sensors to detect field variations, the system achieves high precision position detection in a compact three-dimensional space without requiring long mechanical measurement paths.
3Measurement precision
If a rotating member is used to rotate in conjunction with lens movement, then position detection capability is improved, but the device complexity increases
Solution Approach 1:
The patent merges the position detection function with the existing rotating member that moves with the lens barrel. Magnetic recording members are attached to this rotating member, combining the mechanical movement structure with the magnetic field-based detection system. This integration eliminates the need for separate detection mechanisms while maintaining the ability to detect lens position through the rotation of the integrated magnetic patterns.
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
Enables accurate and high-resolution position detection of the movable lens without moving it, supporting high imaging performance and compact design, suitable for various zooming functions including slow zooming, while maintaining low costs and compatibility with interchangeable lenses.
Implementation Method 1
a second signal detection section that detects a signal which changes in accordance with an amount of rotation of the rotating member
Data Source
AI summary
A lens device includes: a lens that is movable in an optical axis direction; a rotating member that rotates in conjunction with movement of the lens in the optical axis direction; a first signal detection section that detects a signal which changes in accordance with a position of the lens in the optical axis direction; a second signal detection section that detects a signal which changes in accordance with an amount of rotation of the rotating member; a first lens position detection section that detects the position of the lens based on the signal detected by the first signal detection section; a second lens position detection section that detects the position of the lens based on the signal detected by the second signal detection section; and a control section as defined herein.