Shutter Curtain Pre-Driving for Exposure Timing Precision

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Existing image-capturing apparatuses face issues with mechanical shutter delay and decreased curtain speed due to oil starvation and surface force problems, affecting exposure timing and image quality, especially in mirrorless cameras without a mirror box unit.

Innovation Solution

The implementation of a pre-driving operation using a small motion by the curtain unit driven by a stepping motor before the image-capturing operation, which reduces surface force and facilitates lubrication of the rotary shaft, ensuring smooth movement and proper exposure.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If the shutter unit executes the closing operation after resetting electric charge, then proper exposure timing is achieved, but mechanical delay and decreased curtain speed occur due to oil starvation and surface force

Engineering Contradiction:

Improveexposure timing precisionVSAvoidcurtain speed

Core Design Contradiction:

Manufacturing precisionVSSpeed

Solution Approach 1:

The patent applies preliminary action by executing a pre-driving operation before the main image-capturing operation. The actuator drives the curtain unit with a small motion prior to the actual exposure, which prepares the mechanical components by distributing lubricant and reducing surface force. This preliminary action ensures that when the curtain unit executes the closing operation for proper exposure timing, the mechanical delay is minimized and curtain speed is maintained at optimal levels.

Inventive Principle:

Principle #10Preliminary action

2Reliability

If the actuator drives the curtain unit with small motion in pre-driving operation, then surface force is reduced and lubrication is facilitated, but additional operation time is required

Engineering Contradiction:

Improveshutter operation reliabilityVSAvoidoperation time

Core Design Contradiction:

ReliabilityVSLoss of time

Solution Approach 1:

The pre-driving operation is performed as a preliminary action before the main image-capturing sequence. By driving the curtain unit with a small motion in advance, the system prepares the mechanical components for optimal performance. The additional time required is minimal compared to the overall shooting cycle, and it ensures reliable shutter operation by reducing surface force and facilitating lubrication throughout the curtain unit's moving parts.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The patent implements periodic action by incorporating the pre-driving operation into the regular shutter operation cycle. The actuator periodically executes the small motion drive before each image-capturing operation, ensuring consistent lubrication and surface force reduction. This periodic maintenance action is integrated seamlessly into the shooting workflow, minimizing overall time loss while maintaining reliable shutter performance across multiple consecutive shots.

Inventive Principle:

Principle #19Periodic action

3Ease of operation

If the curtain unit is driven by stepping motor, then precise control is achieved, but mechanical friction and oil starvation problems occur

Engineering Contradiction:

Improveshutter control precisionVSAvoidcurtain movement smoothness

Core Design Contradiction:

Ease of operationVSReliability

Solution Approach 1:

The pre-driving operation serves as a preliminary action that prepares the mechanical interface between the stepping motor and curtain unit. By executing a small motion drive before the main operation, the system distributes lubricant to friction surfaces and reduces surface force buildup. This ensures that when the stepping motor drives the curtain unit for precise control during image capture, the mechanical friction is minimized and smooth movement is maintained, preventing oil starvation problems.

Inventive Principle:

Principle #10Preliminary action

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 solution enables the capture of images with proper exposure and reduces exposure variations during consecutive shooting, maintaining a compact camera body size and improving the mechanical shutter's starting characteristics.

Implementation Method 1

facilitates lubrication of the rotary shaft

Methodology Applied

Scientific EffectLubrication: Lubrication

Implementation Method 2

reduces surface force

Methodology Applied

Scientific EffectFriction reduction: Friction

Data Source

PatentUS9325908B2Image-capturing apparatus including shutter unit with pre-driving operation

Publication Date: 2016.04.26 PANASONIC INTELLECTUAL PROPERTY MANAGEMENT CO LTD

AI summary

An image-capturing apparatus includes an image-capturing device having an image-capturing surface, a shutter unit having an aperture configured to allow light from an object to pass through the aperture, and a controller that controls the shutter unit. The shutter unit includes a curtain unit that selectively executes an opening operation of opening the aperture and a closing operation of closing the aperture, and an actuator that drives the curtain unit. The controller is operable to control the shutter unit to execute: an image-capturing operation in which the shutter unit executes the closing operation after resetting an electric charge stored in the image-capturing device; and a pre-driving operation in which the actuator drives the curtain with a small motion before executing the image-capturing operation.