Lens Driving Device Elastic Preload Vibration Suppression
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Solution Overview
Problem
Conventional lens driving devices experience rattling and vibration due to clearance between the lens holder and guide shaft, leading to instability in lens position, which deteriorates the read and write performance of optical pickups.
Innovation Solution
A lens driving device with an elastic portion that reduces rattling and vibration by applying forces perpendicular to the optical axis, using a combination of extension springs to maintain the lens holder's position and a drive mechanism that includes a coil and magnet for precise movement, along with a movement detection system to correct positional variations and detect drive abnormalities.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If a lens holder is supported by guide shafts with clearance to enable movement, then the lens holder can be driven along the optical axis, but rattling and vibration occur due to the clearance, causing lens position instability
Solution Approach 1:
The elastic portion is pre-loaded to apply a pressing force to the lens holder before driving occurs. This preliminary action ensures that the lens holder is constantly pressed against the guide shaft, eliminating clearance-induced rattling and vibration while maintaining smooth movability along the optical axis
Solution Approach 2:
The elastic portion changes the physical state of contact between the lens holder and guide shaft from loose clearance to continuous pressed contact. By altering the contact parameter through elastic deformation, the system achieves both smooth movement and vibration suppression
2Measurement precision
If an expensive stepping motor is used as the drive source, then precise lens positioning is achieved, but the device cost increases
Solution Approach 1:
The invention replaces the expensive stepping motor with a simpler, cheaper drive mechanism consisting of a drive portion that moves the lens holder along the guide shaft. The elastic portion and guide structure provide sufficient positioning precision without requiring costly high-precision motors
Solution Approach 2:
The invention substitutes the complex electromagnetic control system of a stepping motor with a simpler mechanical drive system. The elastic portion provides continuous contact and guidance, while the drive portion enables precise movement through mechanical engagement with the guide shaft, eliminating the need for expensive motorized control
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 suppresses rattling and vibration, ensuring stable lens positioning, improving read and write performance, and allowing for cost reduction by eliminating the need for expensive stepping motors and additional sensors.
Implementation Method 1
an elastic portion that applies a force to the lens holder in directions perpendicular to the optical axis
Implementation Method 2
the drive portion may include a coil and a magnet for driving the lens holder by electromagnetic force
Data Source
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AI summary
A lens driving device includes a lens holder for holding a lens, a supporter portion for supporting the lens holder in a movable manner, a drive portion for driving the lens holder, and an elastic portion for supplying the lens holder with a force in a predetermined direction. The supporter portion includes a shaft engaging with a bearing of the lens holder, and the force in a predetermined direction includes a force in a direction perpendicular to the shaft and a force in a direction to rotate the lens holder about the shaft.