Piezoelectric Camera Actuator for Compact Folded Zoom
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Solution Overview
Problem
Conventional camera modules face challenges in achieving slimness and high-magnification zoom due to structural limitations and the use of stepping motor-type driving mechanisms, which increase the overall volume and weight, and are not well-suited for folded zoom camera modules.
Innovation Solution
A piezo-type camera actuator with independently driven movable parts and opposed piezoelectric elements, utilizing a ball guide and connecting parts with magnets or elastic means to ensure smooth motion, eliminating the need for separate guide pins and simplifying assembly.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Duration of action of moving object
If a stepping motor-type driving mechanism is used to drive the optical system in a conventional folded zoom camera module, then the driving range of the optical system can be increased, but the overall volume and weight of the camera module increase
Solution Approach 1:
The patent replaces the stepping motor-type mechanical driving mechanism with a piezoelectric element-based driving mechanism. The piezoelectric element converts electrical energy directly to mechanical motion through the piezoelectric effect, eliminating the need for a large stepping motor while achieving the required driving range for zoom and auto-focusing functions.
Solution Approach 2:
The patent changes the driving mechanism from a motor-based system to a piezoelectric system, fundamentally altering the operational parameters. The piezoelectric element operates at higher frequencies with smaller displacement amplitudes, achieving the same effective driving range through different physical principles, thereby reducing the overall volume.
2Duration of action of moving object
If a stepping motor-type driving mechanism is used to drive the optical system, then the driving range of the optical system can be increased, but the overall weight of the camera module increases
Solution Approach 1:
The patent replaces the heavy stepping motor with a lightweight piezoelectric element. The piezoelectric element generates sufficient driving force for the optical system through direct electro-mechanical conversion, significantly reducing the weight of the driving mechanism while maintaining the required driving range for zoom and auto-focusing.
3Manufacturing precision
If guide pins are used to guide the motion of the optical system, then the alignment precision can be improved, but the device complexity and assembly difficulty increase
Solution Approach 1:
The patent removes the guide pins from the optical system structure. Instead of using separate guiding components, the invention integrates the guiding function into the housing structure through precisely formed grooves that directly guide the movement of the optical system, thereby simplifying the overall device structure while maintaining alignment precision.
Solution Approach 2:
The patent merges the guiding function with the housing structure. The grooves formed in the housing serve dual purposes: providing structural support and guiding the motion of the optical system. This integration eliminates the need for separate guide pins and reduces assembly complexity.
4Ease of operation
If the optical system is moved in the thickness direction of the mobile device, then the zoom and auto-focusing functions can be realized, but the mobile device thickness increases
Solution Approach 1:
The patent changes the movement direction of the optical system from the thickness direction (vertical) to the lateral direction (horizontal) by utilizing the folded zoom camera module structure with a reflectometer. This dimensional change allows the optical system to move laterally while maintaining a compact thickness, thereby realizing zoom and auto-focusing functions without increasing device thickness.
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 enables miniaturization and light-weight design while ensuring stable, smooth motion of optical components, facilitating mass production and reducing the risk of immovable states or misalignment issues.
Implementation Method 1
a piezo-type driving mechanism using a piezoelectric element becomes popular recently. The piezo-type driving mechanism is realized on a principle of using vibration to drive an optical system, the vibration being generated when a high-frequency pulse voltage is applied to the piezoelectric element.
Implementation Method 2
a reflectometer reflecting light from the outside at 90 degrees is mounted, and an optical system that passes light refracted by the reflectometer is laid in a width or length direction of a mobile device
Implementation Method 3
a ball guide supporting the movable parts such that the movable parts are capable of performing a rolling motion in the first direction
Data Source
AI summary
A camera actuator for realizing auto focusing control and zoom functions and a folded zoom camera module including the same. The camera actuator includes a housing, a driving unit being mounted in the housing and having a vibration shaft and a vibration generator, a movable part mounted so as to correspond to the driving unit and configured to be moved by a driving force, a friction moving part configured to be moved in a first direction on the vibration shaft, and a connecting part mutually connecting the friction moving part and the movable part. The connecting part includes a protrusion or a recess formed on a side surface portion of the friction moving part facing the movable part, and includes a recess or a protrusion formed on a side surface portion of the movable part so as to be engaged with the protrusion or the recess.