Lens Holder Leaf Spring U-Turn Arms for Resonance Damping
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing AF lens holder driving devices require large driving currents due to high restoration forces from leaf springs, leading to power consumption issues and secondary resonance problems when attempting to minimize these forces.
Innovation Solution
The design incorporates U-turn-shaped portions in the leaf springs with stretchable and flexible resin bridges between arm parts, balancing forces and reducing secondary resonance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the restoration force of the leaf spring is increased to support the lens holder, then the lens holder can be properly supported and positioned, but the driving current required increases leading to higher power consumption
Solution Approach 1:
The leaf spring is divided into multiple arm parts (first arm part, second arm part, third arm part) with different functions. The first arm part provides support, the second arm part with U-turn shape provides damping, and the third arm part transmits force. This segmentation allows the spring to provide necessary support while reducing overall restoration force through the damping section.
Solution Approach 2:
The U-turn-shaped second arm part acts as an intermediary element between the first and third arm parts. It serves as a damping agent that absorbs excess restoration force, allowing the leaf spring to support the lens holder while reducing the driving current required by acting as a force-damping mediator.
2Use of energy by moving object
If the restoration force of the leaf spring is decreased to reduce power consumption, then driving current is reduced, but secondary resonance occurs in the lens holder
Solution Approach 1:
The U-turn-shaped second arm part converts the potentially harmful secondary resonance into a beneficial damping effect. By designing this section with specific geometric characteristics (U-turn shape), it absorbs vibrational energy and suppresses resonance while maintaining reduced restoration force, thus converting what would be a harmful vibration into a stabilizing damping mechanism.
3Ease of manufacture
If a simple leaf spring structure is used, then manufacturing is easier, but vibration and impact from outside cause excessive movement of the lens holder
Solution Approach 1:
The leaf spring is designed with dynamic characteristics through its multi-section structure. The varying arm part configurations (straight, U-turn, straight) create different stiffness and damping characteristics along the spring, allowing it to dynamically respond to vibrations and impacts while maintaining manufacturing feasibility as a single-piece formed component.
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
This configuration allows for power saving while effectively suppressing secondary resonance, enhancing the stability and accuracy of the lens holder driving mechanism.
Implementation Method 1
at least one stretchable and flexible resin 45 is provided as a bridge between opposite portions in the U-turn-shaped portion 246a of the arm parts 246
Implementation Method 2
the restoration force (biasing force) of the leaf spring (spring member) and the thrust (driving force) of the driving mechanism are balanced
Data Source
AI summary
In a lens holder driving device, each of an upper plate spring and a lower plate spring, which are respectively provided on an upper side and a lower side of a lens holder, has an inner peripheral side end fixed to the lens holder, an outer peripheral side end fixed to a fixing part, and a plurality of arms. The plurality of arms of the upper plate spring and the plurality of arms of the lower plate spring have substantially identical shapes in a plan view. Each of the plurality of arms includes at least one U-turn shaped portion that is folded over. Either the upper plate spring or the lower plate spring has at least one stretchable and flexible resin that is provided so as to straddle over the mutually opposing parts of the U-turn shaped portion of the plurality of arms.