Imaging Lens Barrel Position Detection Using Magnetic Phase Correction
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Solution Overview
Problem
Existing imaging lens barrels lack the accuracy in detecting the position of imaging lenses, which is crucial for improving image quality on larger and higher resolution display screens.
Innovation Solution
An imaging lens barrel with a rotating body featuring parallel magnetic scales and sensors that calculate phase differences to determine the absolute position of the lens, using correction tables to account for positional deviations and inclinations, ensuring high accuracy in position detection.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conventional position detection methods are used in imaging lens barrels, then the device complexity is reduced, but the measurement precision of lens position is insufficient
Solution Approach 1:
The patent replaces conventional mechanical position detection methods with a magnetic field-based detection system. A magnetic scale is attached to the rotating body that rotates with the lens, and magnetic sensors detect the magnetic field variations to determine lens position. This substitution of mechanical detection with magnetic field detection achieves high-precision measurement while maintaining relatively simple device structure.
Solution Approach 2:
The patent introduces a magnetic scale as an intermediary element between the rotating body and the magnetic sensors. The magnetic scale modulates the magnetic field according to the rotation angle, enabling the sensors to indirectly detect rotational position through magnetic field variations. This intermediary mechanism achieves precise position detection without direct mechanical contact between sensors and rotating parts.
2Measurement precision
If multiple magnetic scales with different wavelengths are used to improve detection accuracy, then the measurement precision increases, but the device complexity increases
Solution Approach 1:
The patent divides the magnetic scale into multiple concentric circles, each with different magnetic wavelengths. The inner circle has a shorter wavelength for detecting fine position variations, while the outer circle has a longer wavelength for determining absolute position. This segmentation of the magnetic scale into multiple functional zones enables both high-resolution and absolute position detection using a single integrated structure.
Solution Approach 2:
The patent transitions from one-dimensional linear encoding to two-dimensional concentric circular encoding. By arranging magnetic scales of different wavelengths in concentric circles on the same plane, the system can simultaneously detect both fine incremental changes (inner circle) and absolute position (outer circle), effectively utilizing spatial dimensionality to encode multiple levels of position information.
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 solution enables precise detection of the imaging lens position, enhancing image quality by correcting phase differences and accounting for variations in posture and inclination, thereby improving the accuracy of lens positioning.
Implementation Method 1
a magnetic sensor device that is provided at a position facing a circumferential surface of the rotating body and includes a first magnetic sensor and a second magnetic sensor, the first magnetic sensor being configured to detect in response to a rotation of the rotating body, from the first magnetic scale, a first phase signal
Data Source
AI summary
An imaging lens barrel includes: a barrel body; a rotating body; a magnetic sensor device; a phase difference calculation section; a correction table memory; a phase difference correction section configured to, when a relative position between the rotating body and the magnetic sensor device according to a posture of the imaging lens barrel is different from that of when a correction table is created, correct a phase difference calculated by the phase difference calculation section according to the relative position and to correct the phase difference calculated by the phase difference calculation section, using a correction value corresponding to the corrected phase difference, and to, when the relative position is not different from that of when the correction table is created, correct the calculated phase difference, using a correction value corresponding to the phase difference calculated by the phase difference calculation section; and an absolute position calculation section.