Variable Focal Length Optical Test Bench

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing optical test benches face difficulties in precisely replacing the pattern at the focus of the lens or concave mirror, requiring complex and expensive mechanical systems, and are hindered by the need for precise positioning to observe reflected waves during autocollimation.

Innovation Solution

An optical system with a deflection device having an adjustable focal distance, comprising two optical lenses with opposite focal lengths and a spacer device to adjust their spacing, allowing for variable vergence light waves to be generated and tested, facilitating easier alignment and testing of optical or optronic systems.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a lens or concave mirror is used to provide variable vergence light waves, then the optical testing function is achieved, but the mechanical positioning system becomes complex and expensive

Engineering Contradiction:
Improveoptical testing functionVSAvoidmechanical positioning system
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent replaces the mechanical positioning system with an optical system. Instead of mechanically moving the screen to precise positions, the invention uses a collimated light wave source combined with a lens whose focal length can be varied. This allows the same optical testing function to be achieved without complex mechanical positioning mechanisms.

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

Solution Approach 2:

The patent changes the parameter of focal length of the lens to achieve variable vergence light waves. By varying the focal length parameter, the system can produce divergent, collimated, or convergent light waves without mechanical repositioning, thus simplifying the overall system while maintaining testing capability.

Inventive Principle:
Principle #35Parameter changes

2Measurement precision

If the screen is positioned precisely at the focal point for autocollimation, then accurate focusing evaluation is achieved, but numerous manipulations and checks are required

Engineering Contradiction:
Improvefocusing evaluation accuracyVSAvoidalignment operation
Core Design Contradiction:
Measurement precisionVSEase of operation

Solution Approach 1:

The patent eliminates the need for precise mechanical positioning of the screen by using a collimated light wave source. The variable focal length lens automatically provides the correct vergence for autocollimation, removing the need for manual manipulation and checking of screen position while maintaining measurement precision.

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

Solution Approach 2:

The system performs self-alignment through the optical properties of the collimated light source and variable focal length lens. The optics themselves provide the necessary alignment references, eliminating the need for external manipulation and checking procedures.

Inventive Principle:
Principle #25Self-service

3Reliability

If the screen is not precisely at the focal point, then autocollimation cannot be observed, but precise positioning mechanisms are complex and expensive

Engineering Contradiction:
Improveautocollimation observationVSAvoidpositioning mechanism
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent replaces complex positioning mechanisms with a collimated light wave source and variable focal length lens system. This optical approach ensures reliable autocollimation observation without requiring expensive and complex mechanical positioning devices.

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

Enables precise and efficient adjustment of light waves for testing optical systems, reducing mechanical complexity and cost, while allowing for accurate evaluation of focusing quality through adjustable focal lengths from infinity to predetermined values.

Implementation Method 1

a first optical lens intended to receive the collimated light wave and to deflect it to provide a light wave, called the intermediate light wave

Methodology Applied
Scientific EffectRefraction: Refraction

Implementation Method 2

a second optical lens intended to receive the intermediate light wave and to deflect it to provide the test light wave

Methodology Applied
Scientific EffectRefraction: Refraction

Implementation Method 3

a collimator arranged to receive the target light wave and collimate it to provide the collimated light wave

Methodology Applied
Scientific EffectCollimation: Lens

Data Source

PatentEP2802854B1Optical device, optical test bench and optical test method
Publication Date: 2019.01.23 SPHEREA TEST & SERVICES
  • EP2802854B1 patent drawingFigure 1~5
  • EP2802854B1 patent drawingFigure 2

AI summary

This optical system comprises: a device (106) for generating a plane light wave, called a collimated light wave (OLcol); and a device (114) for deviating the collimated light wave so as to provide a light wave, called a test light wave (OLtest), the deviating device (114) having an adjustable focal length.