Lens Driving Coil Layout for Stable Miniature Camera Modules
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing technologies face challenges in applying voice coil motors to subminiature, low-power camera modules, particularly in small electronic devices like smartphones, due to issues such as magnetic-field interference, reduced electromagnetic force, and potential disconnection or separation of coils from the bobbin, exacerbated by shocks and hand shaking.
Innovation Solution
A lens moving apparatus with a bobbin design that includes first and second coils secured by elastic members, protrusions, and a housing configuration that minimizes magnetic interference and enhances electromagnetic force, while preventing coil disconnection and separation, utilizing a sensing magnet and position sensor for precise control.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If voice coil motor is applied to subminiature camera module, then device size is reduced, but magnetic-field interference increases and electromagnetic force decreases
Solution Approach 1:
The camera module is divided into separate functional regions: a first region for the voice coil motor and a second region for the Hall sensor. This spatial segmentation reduces magnetic-field interference by isolating the magnetic components from the sensing components, allowing the miniaturized module to maintain both compact size and reduced interference.
Solution Approach 2:
A magnetic shield or non-magnetic barrier is introduced as an intermediary element between the voice coil motor and the Hall sensor. This intermediary structure blocks or redirects magnetic field lines, preventing direct magnetic-field interference while maintaining the compact subminiature form factor of the camera module.
2Reliability
If coil is secured tightly to bobbin, then connection reliability is improved, but coil flexibility and positioning adjustability are reduced
Solution Approach 1:
The coil is attached to the bobbin using an elastic member that provides both mechanical connection and positional adjustment capability. The elastic attachment allows the coil to be securely fixed while maintaining flexibility for positioning adjustments during assembly and calibration, resolving the contradiction between connection reliability and positioning adaptability.
3Reliability
If elastic member is used to connect coil to bobbin, then coil connection reliability is improved, but magnetic-field interference may increase
Solution Approach 1:
A non-magnetic elastic member with porous or mesh structure is used to connect the coil to the bobbin. This porous elastic member provides mechanical support and reliable connection while allowing magnetic field lines to pass through with minimal interference, thus maintaining both connection reliability and reduced magnetic-field interference.
Solution Approach 2:
The elastic member is constructed from composite materials that combine elastic properties for reliable mechanical connection with non-magnetic characteristics to minimize magnetic-field interference. This composite approach allows simultaneous achievement of both connection reliability and reduced magnetic interference in the compact camera module.
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 effectively reduces magnetic interference, increases electromagnetic force, and prevents coil disconnection and separation, ensuring stable operation of the camera module despite shocks and hand shaking.
Implementation Method 1
a first coil (120-1) and a second coil (120-2) which are disposed on two facing side portions (110b-1 and 110b-2) of the bobbin (110) and are connected in series to each other
Implementation Method 2
an upper elastic member (150) and a lower elastic member (160) which are coupled to the bobbin (110) so as to elastically support the bobbin (110)
Data Source
Figure 1
Figure 2~3
Figure 4~5
AI summary
An embodiment comprises: a housing; a bobbin arranged in the housing; a first coil arranged at a first side part of the bobbin; a second coil arranged at a second side part positioned on the side opposite to the first side part of the bobbin; a first magnet facing the first coil and arranged in the housing; a second magnet facing the second coil and arranged in the housing; a first elastic member coupled to the bobbin; a second elastic member comprising a first elastic unit and a second elastic unit coupled to the bobbin; and a circuit board arranged in the housing and having first and second terminals, wherein one end of the first coil is coupled to one area of the first elastic member and the other end of the first coil is coupled to the first elastic unit, one end of the second coil is coupled to another one area of the first elastic member and the other end of the second coil is coupled to the second elastic unit, the first elastic unit is connected to the first terminal of the circuit board, and the second elastic unit is connected to the second terminal of the circuit board.