Optical Unit Shake Correction Sensor Overlap
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Solution Overview
Problem
The existing optical units with shake correction functions are hindered in downsizing in the direction intersecting the optical axis due to the arrangement of Hall elements between magnets and magnetic members.
Innovation Solution
The optical unit design includes a magnetic detection sensor overlapping the magnetic member in a direction orthogonal to the thickness of the magnetic member, with a magnetic member formed in a square frame shape and disposed on both sides of the sensor, allowing for reduced size and improved alignment of components, enhancing magnetic attraction force and operational sensitivity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If Hall elements are disposed between magnets and magnetic members, then magnetic detection function is achieved, but the optical unit cannot be downsized in the radial direction
Solution Approach 1:
The Hall element is moved from the radial direction (between magnets and magnetic members) to the optical axis direction (behind the magnetic member), changing the detection dimension. This allows the radial direction to be minimized while maintaining detection functionality through the new axial arrangement.
Solution Approach 2:
The Hall element is positioned behind the magnetic member, nesting the detection function within the existing magnetic structure. The magnetic member serves as both a return force generator and a positioning element for the Hall element, eliminating the need for additional radial space.
2Measurement precision
If magnetic detection sensor is positioned closer to magnets, then detection sensitivity is improved, but radial size increases
Solution Approach 1:
The detection sensor is repositioned from radial proximity to axial proximity, detecting the magnetic field through the magnetic member rather than directly from the magnet. This maintains detection capability while minimizing radial dimension.
Solution Approach 2:
The magnetic member acts as an intermediary between the magnet and Hall element. The Hall element detects the magnetic field through the magnetic member, which transmits and concentrates the magnetic flux, maintaining detection sensitivity without requiring direct radial proximity.
3Ease of manufacture
If magnetic member is formed in square frame shape with connecting portions, then assembly ease is improved, but manufacturing precision requirements increase
Solution Approach 1:
The magnetic member is divided into first and second members connected by connecting portions. This segmentation allows independent positioning and adjustment of each segment, facilitating easier assembly while the connecting portions provide flexible tolerance compensation.
Solution Approach 2:
The connecting portions are designed with asymmetric features (protrusions and recesses) that enable straightforward alignment and positioning during assembly, reducing the need for high-precision machining while ensuring proper orientation.
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 enables the optical unit to be downsized in the radial direction, reduces the time for returning to the original position, and stabilizes the shake correcting ability while maintaining precision and drive torque.
Implementation Method 1
a magnetic detection sensor that detects a magnetic field of the magnet
Implementation Method 2
a magnetic member that returns the movable body to an original position by a magnetic attraction force with the magnet
Implementation Method 3
a swing drive mechanism that includes a magnet and a coil forming a magnet-coil pair, with a counterpart of the magnet-coil pair being fixed to the movable body and another counterpart to the fixed body, and swings the movable body relative to the fixed body
Data Source
AI summary
An optical unit having a shake correction function may include a movable body including an optical module; a fixed body that supports the movable body in a swingable manner; a swing drive mechanism that includes a magnet and a coil forming a magnet-coil pair, with a counterpart of the magnet-coil pair being fixed to the movable body and another counterpart to the fixed body, and swings the movable body relative to the fixed body; a magnetic detection sensor that detects a magnetic field of the magnet; and a magnetic member that returns the movable body to an original position by a magnetic attraction force with the magnet. The magnetic detection sensor overlaps the magnetic member as viewed in a direction orthogonal to a thickness direction of the magnetic member.