Blade Drive Device Shutter Mechanism Impact Resistance
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Electromagnetic drive-type focal plane shutters in cameras face challenges in achieving miniaturization, quick shutter operation, and impact resistance due to the trade-off between detent torque for holding curtains open and the risk of unexpected movement during power loss.
Innovation Solution
A blade drive device with a substrate, front and rear curtains, and a blade position holding member that pivots to regulate curtain movement, allowing the device to stay at an entry position without increasing detent torque, ensuring miniaturization, quick operation, and impact resistance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the detent torque of the electromagnetic actuator is increased to improve the holding force of the front curtain and rear curtain when power is not supplied, then the holding reliability is improved, but the shutter operation speed decreases and the size of the electromagnetic actuator increases
Solution Approach 1:
A blade position holding member is introduced as an intermediary mechanical structure that physically blocks the curtains from moving in the closing direction. This mediator absorbs the impact force directly, preventing the need to increase detent torque, thereby maintaining both holding reliability and fast operation speed
2Reliability
If the detent torque of the electromagnetic actuator is increased to improve the holding force, then the holding reliability is improved, but the size of the electromagnetic actuator increases
Solution Approach 1:
The blade position holding member serves as a mechanical intermediary that provides impact resistance without requiring increased actuator size. By transferring the impact resistance function to this separate component, the actuator can remain compact while still achieving reliable holding force
Solution Approach 2:
The holding function is segmented into two parts: the electromagnetic actuator provides controlled positioning, while the blade position holding member provides passive mechanical blocking. This segmentation allows each component to be optimized independently, keeping the actuator small while ensuring reliable holding
3Speed
If the detent torque is decreased to quicken the shutter operation, then the shutter operation speed is improved, but the front curtain and rear curtain may be unexpectedly moved in closing direction due to drop impact
Solution Approach 1:
The blade position holding member acts as a mechanical intermediary that absorbs impact forces from drops. This allows the detent torque to be kept low for fast operation while the intermediary structure provides the necessary impact resistance to prevent unexpected curtain movement
4Device complexity
If an electromagnetic drive-type FP shutter is used to miniaturize and simplify the structure, then the device complexity is reduced and size is decreased, but the holding force and impact resistance become difficult to ensure
Solution Approach 1:
The blade position holding member is a simple mechanical intermediary that adds minimal complexity while significantly improving holding force and impact resistance. This straightforward blocking structure complements the electromagnetic actuator without requiring complex control systems or additional active components
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 of the camera's shutter mechanism while ensuring quick operation and impact resistance by regulating curtain movement without relying on high detent torque, preventing unintended curtain closure during power loss.
Implementation Method 1
the electromagnetic drive-type FP shutter holds the open position of the front curtain and the rear curtain by using a detent torque (magnetic attraction force in a state where power is not supplied) of the electromagnetic actuator
Data Source
AI summary
There is provided a blade drive device including a substrate that has an opening, a front curtain and a rear curtain that are movable along an opening surface of the opening so as to open and close the opening, a front curtain locking portion that interlocks with opening and closing operations of the front curtain, a rear curtain locking portion that interlocks with opening and closing operations of the rear curtain, and a regulation lever that is configured to be pivotally movable around a lever axis, and that is capable of entry and escape between an entry position which enters each operation trajectory of the front curtain locking portion and the rear curtain locking portion in response to the opening and closing operations of the front curtain and the rear curtain and an escape position escaped from the operation trajectory. The regulation lever has a front curtain regulation portion which can be locked by the front curtain locking portion from one side around the lever axis at the entry position so as to regulate movement of the front curtain in a closing direction, and a rear curtain regulation portion which can be locked by the rear curtain locking portion from the other side around the lever axis at the entry position so as to regulate movement of the rear curtain in a closing direction.