Focal Plane Shutter Set Member Merging Drive Portions

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Solution Overview

Problem

Focal plane shutters have a complex and enlarged structure due to separate components for moving the brake member away from the drive member and for moving the drive member to the start position, leading to increased size.

Innovation Solution

A focal plane shutter design featuring a board with opening blades, a drive member biased towards the terminal position, a brake member for slowing down the drive member, and a set member that rotates in one direction to move the drive member from the terminal to the start position, incorporating a single drive portion that both moves the brake member away and the drive member to the start position.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If separate drive portions are provided for moving the brake member away from the drive member and for moving the drive member to the start position, then the brake member can be moved away from the drive member and the drive member can be moved to the start position, but the structure of the set member becomes complicated and the size of the focal plane shutter increases

Engineering Contradiction:

Improvebrake member movement reliabilityVSAvoidset member structure complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The patent combines two separate drive portions into a single integrated drive portion that performs both functions: moving the brake member away from the drive member and moving the drive member to the start position. This single drive portion includes a drive lever with a brake member moving portion and a drive member moving portion, eliminating the need for separate components and reducing structural complexity while maintaining the reliability of both movements.

Inventive Principle:

Principle #5Merging (Combining)

2Reliability

Engineering Contradiction:

Improvebrake member movement reliabilityVSAvoidfocal plane shutter size

Core Design Contradiction:

ReliabilityVSVolume of moving object

Solution Approach 1:

The patent merges two separate drive mechanisms into one compact drive portion, significantly reducing the space required. The single drive lever integrates both the brake member moving portion and the drive member moving portion, allowing both functions to be performed within a smaller volume, thus reducing the overall size of the focal plane shutter while maintaining functional reliability.

Inventive Principle:

Principle #5Merging (Combining)

3Reliability

If a brake member is added to prevent bounding of the drive member, then the drive member bounding is prevented, but the structure becomes more complicated and the size increases

Engineering Contradiction:

Improvedrive member positioning reliabilityVSAvoidset member structure complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The brake member is integrated into the same drive portion that moves the drive member to the start position. The drive lever includes both the brake member moving portion and the drive member moving portion, allowing the brake member to be actuated as part of the same mechanical sequence without requiring separate control mechanisms, thus preventing drive member bounding while minimizing structural complexity.

Inventive Principle:

Principle #5Merging (Combining)

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 design simplifies the set member structure and reduces the overall size of the focal plane shutter by eliminating the need for separate drive portions, resulting in a more compact optical device.

Implementation Method 1

a brake member supported to abut and move away from the drive member positioned at the terminal position, and biased to abut the drive member positioned at the terminal position

Methodology Applied

Scientific EffectFriction: Friction

Implementation Method 2

a drive member movable between a start position and a terminal position, biased toward the terminal position

Methodology Applied

Scientific EffectElasticity: Elasticity

Implementation Method 3

a set member rotatable in only one direction, and moving the drive member from the terminal position to the start position

Methodology Applied

Scientific EffectMechanical Advantage: Mechanical Advantage

Data Source

PatentUS8376635B2Focal plane shutter and optical device using same

Publication Date: 2013.02.19 SEIKO GRP CORP

AI summary

A focal plane shutter includes: a board including an opening; blades capable of opening and closing the opening; a drive member movable between a start position and a terminal position, biased toward the terminal position, and driving the blades; a brake member supported to abut and move away from the drive member positioned at the terminal position, and biased to abut the drive member positioned at the terminal position; and a set member rotatable in only one direction, and moving the drive member from the terminal position to the start position; wherein the set member includes a drive portion abutting the brake member to move the brake member away from the drive member and then abutting the drive member to move the drive member toward the start position.