Varifocal Lens Camera Distance Measurement

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Solution Overview

Problem

Manufacturing equipment faces limitations in reducing size while maintaining accurate control of mechanical operations due to the need for additional sensor installations for distance measurement.

Innovation Solution

Utilizing a built-in camera with a varifocal liquid-crystal lens to measure distances to target objects, eliminating the need for additional sensors and improving control accuracy through image processing and focal length adjustment.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If additional sensors are installed to measure distance for accurate control, then measurement precision is improved, but device complexity and size increase

Engineering Contradiction:
Improvedistance measurement accuracyVSAvoidequipment size
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The camera is designed to perform multiple functions: it captures images for visual inspection and simultaneously measures distance by analyzing the focal length adjustments required to achieve focus. This eliminates the need for separate distance measurement sensors, reducing device complexity while maintaining measurement precision.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Solution Approach 2:

The camera system uses its own operational parameters (focal length adjustments) to derive distance information. By monitoring how the focal length changes to achieve focus on the target object, the system self-determines distance without requiring external measurement devices.

Inventive Principle:
Principle #25Self-service

2Manufacturing precision

If additional sensors are installed to measure distance, then manufacturing precision is improved, but device complexity increases

Engineering Contradiction:
Improvecontrol accuracy of mechanical operationsVSAvoidnumber of additional devices
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The camera serves dual purposes: quality inspection through imaging and positioning through distance measurement. This multi-functionality enables improved manufacturing precision without adding separate measurement devices, thus avoiding increased device complexity.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Solution Approach 2:

The patent replaces potential mechanical distance measurement sensors with an optical-based method using the camera's focusing mechanism. This substitution maintains or improves measurement accuracy while reducing the number of mechanical components required.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

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

Enhances the accuracy of mechanical operations by using the existing camera for distance measurement, reducing equipment size and improving control precision without additional sensor installations.

Implementation Method 1

a varifocal lens, and a relationship between an amount of voltage applied to the varifocal lens and a focal length of the varifocal lens is stored in advance in a memory

Methodology Applied
Scientific EffectLiquid crystal variable focal length effect: Liquid Crystals

Data Source

PatentEP2981162B1Manufacturing equipment
Publication Date: 2019.04.24 FUJI CORP
  • EP2981162B1 patent drawingFigure 1
  • EP2981162B1 patent drawingFigure 2
  • EP2981162B1 patent drawingFigure 3

AI summary

An object of this disclosure is to provide a manufacturing equipment that can measure the distance to a target object, and improve accuracy of the control of mechanical operations. The manufacturing equipment includes a focusing control section that causes a varifocal lens to bring the target object into focus by adjusting a voltage applied to the varifocal lens based on an electric signal of an imaging element; a memory section configured to store a lens characteristic in advance which represents a relationship between the voltage applied to the varifocal lens and the distance between the target object and a camera; and a distance measurement section configured to measure the distance to the target object based on the voltage applied to the varifocal lens when the focusing control section brings the target object into focus, and the lens characteristic.