Autofocus Contrast Enhancement via Electronic Shutter

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Existing autofocus devices in optical measuring devices, such as microscopes, face issues with reduced throughput, high noise during switching operations, and short device lifespan due to the use of solenoids and springs for pattern projection and retraction.

Innovation Solution

An autofocus device with a driving mechanism that displaces the objective lens based on image contrast, incorporating a pattern projection system with a shutter and light dividing/synthesizing elements to project patterns electronically, reducing mechanical noise and extending device life.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If a pattern projection plate is advanced into or retreated from the optical path using a solenoid and spring mechanism, then pattern projection and retraction can be performed, but throughput is reduced and noise is generated during switching operations

Engineering Contradiction:

Improvepattern projection capabilityVSAvoidthroughput

Core Design Contradiction:

Adaptability or versatilityVSProductivity

Solution Approach 1:

The patent replaces the mechanical solenoid and spring-based pattern projection plate mechanism with an electronic shutter system. The electronic shutter uses a liquid crystal plate or mechanical shutter actuated by electronic control signals, eliminating the need for mechanical movement of the pattern projection plate. This substitution of mechanical systems with electronic control systems resolves the contradiction by maintaining pattern projection capability while eliminating mechanical noise and improving throughput through faster, quieter operation.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

2Adaptability or versatility

Engineering Contradiction:

Improvepattern projection capabilityVSAvoiddevice lifespan

Core Design Contradiction:

Adaptability or versatilityVSReliability

Solution Approach 1:

The patent replaces the mechanical solenoid and spring-based pattern projection plate mechanism with an electronic shutter system. The electronic shutter uses a liquid crystal plate or mechanical shutter actuated by electronic control signals, eliminating the need for mechanical movement of the pattern projection plate. This substitution of mechanical systems with electronic control systems resolves the contradiction by maintaining pattern projection capability while eliminating mechanical wear and improving throughput through faster, quieter operation.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

3Adaptability or versatility

If a pattern projection plate is advanced into the optical path, then pattern projection can be performed for focusing, but the device structure becomes more complex

Engineering Contradiction:

Improvepattern projection capabilityVSAvoidoptical path structure

Core Design Contradiction:

Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent merges the pattern projection function with the existing optical path by integrating the electronic shutter directly into the illumination optical path. The liquid crystal plate or mechanical shutter is positioned within the existing optical pathway, allowing pattern projection without requiring separate mechanical insertion and retraction mechanisms. This merging of functions into a unified optical path reduces structural complexity while maintaining pattern projection capability.

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 solution enhances throughput, minimizes noise during switching, and increases device lifespan by using electronic shutters and light management to focus on low-contrast surfaces like mirrors or glass, while simplifying the device structure and reducing parts and costs.

Implementation Method 1

a liquid crystal plate that can switch to a state in which light can be transmitted or intercepted due to application of current or non-application of current

Methodology Applied

Scientific EffectLiquid crystal effect: Liquid Crystals

Implementation Method 2

an objective lens that converges light at a measurement surface of a measurement object

Methodology Applied

Scientific EffectOptical convergence: Lens

Implementation Method 3

a projection lens, and a shutter are provided in the pattern-projection-optical-system optical path

Methodology Applied

Scientific EffectOptical projection: Lens

Data Source

PatentUS8258448B2Autofocus device with contrast enhancement

Publication Date: 2012.09.04 MITUTOYO CORP

AI summary

An autofocus device includes an objective lens, an observation optical system, a driving mechanism that displaces the objective lens in an optical axis direction thereof, an illumination-optical-system optical path used to illuminate a measurement surface of a measurement object through the objective lens with light, and a pattern-projection-optical-system optical path. An electronic control shutter, a pattern projection plate having a predetermined pattern formed thereon, and a projection lens are provided in the pattern-projection-optical-system optical path.