Camera Lens Drive Sensor Mounting for Stable Optical Axis
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Solution Overview
Problem
Conventional camera modules face issues with accurate auto focus and feedback due to adhesive-related optical axis position changes, poor conductive coupling between driving parts and sensors, and vibration-induced resolution deterioration, especially in miniaturized and low-power mobile phone cameras.
Innovation Solution
A lens driving device with a housing that securely fixes the sensor's upper and lower surfaces, incorporates a bobbin with a coil and magnets, and optimizes conductive pad placement for improved workability and reliability, while restricting vibration-induced noise and shock effects.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If adhesive is coated and mounted in the manufacturing process to fix the sensor and sensing magnet, then the components are secured in place, but the optical axis direction position of the sensor and sensing magnet changes, leading to inaccurate auto focus detection
Solution Approach 1:
The housing is divided into an upper housing and a lower housing that can be separately assembled. The sensor is fixed to the lower housing, and the sensing magnet is fixed to the upper housing. This segmentation allows precise positioning of each component relative to its housing without being affected by adhesive coating variations, thereby maintaining accurate optical axis alignment.
Solution Approach 2:
The housing acts as an intermediary structure between the sensor and the sensing magnet. By fixing these components to the housing rather than directly to each other, the housing provides a stable reference frame that maintains the optical axis direction position, eliminating the positioning errors caused by adhesive coating variations.
2Volume of moving object
If the camera module is miniaturized to reduce size and power consumption, then the device becomes more compact, but the electromagnetic force of the lens driving device decreases and spring force of elastic members decreases, affecting performance
Solution Approach 1:
The patent optimizes the parameters of the electromagnetic components and elastic members to maintain sufficient force in a miniaturized structure. By carefully selecting and adjusting parameters such as coil turns, magnet strength, and spring constants, the system achieves adequate driving force and restoring force despite the reduced size.
Solution Approach 2:
The patent employs composite structures and materials to maximize the force output within the constrained miniaturized space. The use of high-strength, high-elasticity materials for the spring members and optimized electromagnetic composite structures enables the small camera module to maintain sufficient driving and restoring forces.
3Reliability
If conductive members are coupled to form conductive lines for driving parts and sensor, then electrical connection is established, but peaks and workability deteriorate due to poor coupling
Solution Approach 1:
The conductive members are pre-formed with predetermined shapes and configurations before assembly. This preliminary preparation ensures that when the components are assembled, the conductive members can be easily coupled to form reliable conductive lines without requiring complex alignment or adjustment procedures, thereby improving both workability and coupling quality.
4Volume of moving object
If a linear vibration motor is used to replace the VCM for miniaturization, then the camera module can be miniaturized, but vibration is generated in the optical axis direction of the lens driving device, deteriorating camera resolution and generating noise
Solution Approach 1:
The patent utilizes the vibration generated by the linear vibration motor to drive the lens for auto focus operation. By controlling the vibration frequency and amplitude, the system converts the harmful vibration into a useful driving force for lens movement, thereby achieving both miniaturization and functional performance while minimizing resolution deterioration and noise.
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
Maintains consistent optical axis direction, enhances auto focus performance, improves conductive coupling reliability, and reduces vibration-related resolution degradation, enabling better camera functionality in miniaturized mobile devices.
Implementation Method 1
a coil disposed on the bobbin; a first magnet which is disposed on the housing and faces the coil
Implementation Method 2
a second magnet disposed on the bobbin; and a sensor which is disposed on the housing and faces the second magnet
Data Source
AI summary
The present embodiments relates to a lens driving device including: a housing; a bobbin disposed in the housing; a coil disposed on the bobbin; a first magnet which is disposed on the housing and faces the coil; a second magnet disposed on the bobbin; and a sensor which is disposed on the housing and faces the second sensor, wherein the sensor includes an upper surface, a lower surface disposed opposite the upper surface, an inner surface facing the second magnet, an outer surface disposed opposite the inner surface, and both lateral surfaces connecting the inner surface with the outer surface, the upper surface and the lower surface of the sensor are fixed to the housing, and one of the side surfaces of the sensor is opened.