Optical Unit Resonance Prevention via Frequency Shifting
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Solution Overview
Problem
Existing optical units with shake correction functions face challenges in preventing resonance when mounted on movable bodies like vehicles or radio-controlled helicopters, as the natural vibration frequencies of the movable module and the support structure overlap with the vibration frequency band of the movable body, leading to resonance issues during acceleration and deceleration.
Innovation Solution
The optical unit incorporates a gimbal mechanism with a movable frame having elasticity and a spring member connected to the support body, where the natural vibration frequencies of the movable frame and spring member are shifted to avoid overlapping with the vibration frequency band of the movable body, ensuring the optical unit can effectively correct shakes without resonating.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a movable module is swingably supported by a gimbal mechanism with a movable frame having elasticity and a spring member, then the shake correction capability is improved, but the natural vibration frequencies of the movable frame and spring member overlap with the vibration frequency band of the movable body, causing resonance
Solution Approach 1:
The patent changes the physical parameters of the movable frame and spring member to shift their natural vibration frequencies. Specifically, the movable frame's natural vibration frequency is adjusted to 200-400 Hz and the spring member's natural vibration frequency is adjusted to 50-100 Hz, ensuring these frequencies do not overlap with the movable body's vibration frequency band during operation.
2Object-affected harmful factors
If the natural vibration frequencies of the movable frame and spring member are shifted to avoid overlapping with the vibration frequency band, then resonance is prevented, but the complexity of frequency tuning and validation increases
Solution Approach 1:
The patent performs preliminary frequency tuning during the design and manufacturing stage. The movable frame and spring member are designed with specific structural parameters that pre-determine their natural vibration frequencies to be within the desired ranges. This preliminary action ensures resonance prevention without requiring complex real-time tuning mechanisms.
3Object-affected harmful factors
If a buffer member or buffer mechanism is added to prevent resonance, then resonance is suppressed, but the mounting labor and device complexity increase
Solution Approach 1:
The patent extracts the resonance prevention function from a separate buffer mechanism and integrates it directly into the gimbal mechanism's structural components (movable frame and spring member). By making these components themselves have appropriate natural vibration frequencies, the resonance prevention function is built-in, eliminating the need for separate buffer members or complex mounting procedures.
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 effectively suppresses resonance in the movable module, allowing for stable image capture even during the acceleration and deceleration of the movable body, by ensuring the natural vibration frequencies of the frame and spring member are lower than the vibration frequency band of the body, thus preventing resonance and maintaining posture holding capabilities.
Implementation Method 1
a gimbal mechanism including a movable frame having elasticity configured to swingably support the movable module between the movable module and the support body
Implementation Method 2
a spring member connected to the movable module and the support body for holding posture of the movable module
Implementation Method 3
a shake correction drive mechanism configured to swing the movable module
Data Source
AI summary
An optical unit with a shake correction function may include a movable module holding an optical element, a support body including a body part surrounding the movable module, a gimbal mechanism including a movable frame having elasticity and configured to swingably support the movable module between the movable module and the support body, a spring member connected to the movable module and the support body for holding posture of the movable module, and a shake correction drive mechanism configured to swing the movable module. When a natural vibration frequency of the movable frame is “fa”, a natural vibration frequency of the spring member is “fb”, and a vibration frequency band of a movable body on which the support body is mounted is “fw”, the natural vibration frequency “fa” and the natural vibration frequency “fb” are shifted from the vibration frequency band “fw”. Further, it may be preferable that a difference between the natural vibration frequency “fa” and the natural vibration frequency “fb” is set to be 135 Hz or more.