Lens Driving Device Guide Portion Stabilizes Magnet-Coil Spacing
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Solution Overview
Problem
Conventional lens driving devices face issues with height deviations during assembly, leading to inconsistent performance in auto-focusing and handshake compensation functions. Additionally, the FPCB soldered to the OIS coil is prone to cracking under impact, affecting the reliability of the lens driving motor.
Innovation Solution
The proposed lens driving device includes a bobbin with a coil unit wound on its outer surface, a holder member with a magnet, and elastic members for support. The device also features a guide portion on the base to maintain the correct positioning of circuit boards and a cover layer that extends to cover the copper portion, enhancing the structural integrity and preventing cracking of the FPCB.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If multiple circuit boards are laminated during assembly to implement handshake compensation function, then the device functionality is improved, but height deviations occur depending on assembly workers, leading to manufacturing precision deterioration
Solution Approach 1:
The patent introduces a guide portion with a specific local structure (protrusion penetrating the first circuit board and contacting the second circuit board) to locally control and standardize the height relationship between laminated circuit boards. This local structural feature ensures consistent spacing between the driving magnet and FP coil regardless of assembly worker variations.
2Reliability
If FPCB is soldered to OIS coil to connect circuits, then electrical connectivity is achieved, but the FPCB is prone to cracking when impact is applied, reducing reliability
Solution Approach 1:
The patent introduces a cover layer that extends to cover the copper portion of the FPCB before impact occurs. This cover layer acts as a protective cushioning structure that prevents cracking of the FPCB when impact is applied, thereby maintaining circuit connectivity and reliability under harsh conditions.
3Ease of manufacture
If the distance between driving magnet and FP coil is not stabilized, then assembly flexibility is maintained, but auto-focus and handshake compensation performance become inconsistent
Solution Approach 1:
The guide portion acts as an intermediary structure between the first and second circuit boards, maintaining a predetermined distance between the driving magnet and FP coil. This intermediary structure ensures consistent performance of auto-focus and handshake compensation functions while allowing assembly flexibility through the guide portion's integrated design.
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 stabilizes the distance between the driving magnet and the FP coil during assembly, ensuring reliable auto-focus and handshake compensation functions. Additionally, the enhanced structural design of the FPCB prevents cracking under impact, thereby improving the overall reliability and performance of the lens driving device.
Implementation Method 1
a voice coil motor operates by an electromagnetic interaction between a magnet fixed in a housing and a coil unit wound on an outer circumferential surface of a bobbin
Implementation Method 2
a bobbin being moved in upward and downward directions is elastically supported by an upper and a first elastic member
Implementation Method 3
the FPCB (Flexible Printed Circuit Board) used in the lens driving motor is coupled to the OIS (Optical Image Stabilization) coil via a plurality of soldering
Data Source
AI summary
A lens driving device is provided, including: a holder member; a first driving unit disposed at the holder member; a base disposed at a lower side of the holder member and spaced apart from the holder member; a first circuit board disposed at an upper surface of the base; a second circuit board including a second driving unit facing the first driving unit, and disposed at an upper surface of the first circuit board; a support member supporting the holder member with respect to the base; and a guide portion protruded from an upper surface of the base, wherein the guide portion supports the second circuit board. In an embodiment, a coil at the second circuit board and a magnet at the holder member may be assembled at a predetermined interval, such that reliability of the product with respect to performance of handshake compensation device can be enhanced.