Lens Driving Module Buffer Structure for Shock-Stable Autofocus
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Solution Overview
Problem
Existing lens moving apparatuses in miniaturized camera modules are prone to damage from shocks, fluctuation in stroke range, and foreign matter-induced defects, limiting lens selection and reliability in autofocus driving.
Innovation Solution
Incorporation of buffers and specific structural designs in the bobbin and base to absorb shocks, prevent damage, and minimize foreign matter exposure, along with non-overlapping holder designs to enhance lens selection and AF driving reliability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If the lens moving apparatus is miniaturized to reduce size, then the camera module size is reduced, but the apparatus becomes more susceptible to shock damage and stroke range fluctuation
Solution Approach 1:
A buffer member is disposed between the bobbin and the cover member to cushion shocks before they reach the bobbin. The buffer member absorbs impact energy during external shocks, preventing direct transmission to the bobbin and maintaining stable stroke range in miniaturized camera modules.
2Volume of moving object
If the bobbin is positioned closer to the cover member to reduce size, then the camera module is miniaturized, but the bobbin becomes vulnerable to shock damage
Solution Approach 1:
The buffer member serves as an intermediary element positioned between the bobbin and the cover member. It mediates the interaction during shock events, absorbing impact energy and preventing direct contact between the bobbin and cover member, thereby protecting the bobbin in miniaturized configurations.
3Productivity
If the holder structure is simplified to improve manufacturing, then production efficiency increases, but foreign matter can cause image sensor defects
Solution Approach 1:
The foreign matter collection portion is extracted as a separate functional element within the holder structure. It actively collects and removes foreign matter from the optical path, preventing contamination of the image sensor while maintaining a relatively simple overall holder design for efficient manufacturing.
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
Prevents damage to components, stabilizes stroke range, reduces foreign matter defects, and improves lens selection and AF driving reliability in miniaturized camera modules.
Implementation Method 1
a buffer disposed between the inner surface of an upper plate of the cover member and an upper surface of the bobbin in the optical-axis direction so as to correspond to a position where a shock is likely to be applied to the bobbin
Data Source
Figure 1
Figure 2~3A
Figure 3B~3C
AI summary
One embodiment comprises: a cover member including an upper plate and a side plate connected to the upper plate; a housing arranged in the cover member; a bobbin arranged in the housing; a coil coupled to the bobbin; a magnet which is arranged in the housing and faces the coil; a base arranged under the bobbin; and a first buffer unit arranged on the top surface of the bobbin corresponding to or facing the upper plate of the cover member, wherein the cover member includes a protrusion part extending in the direction toward the bobbin from the upper plate, and the distance in the optical axis direction between the protrusion part and the top surface of the bobbin is no greater than the distance in the optical axis direction between the first buffer unit and the inner surface of the upper plate of the cover member.