Five-Lens Optical Inspection System for Variable Magnification

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Solution Overview

Problem

Existing optical inspection systems face limitations in magnifying object details without increasing numerical aperture, leading to decreased illuminance and the formation of shadows, making it difficult to resolve object details within shadow areas.

Innovation Solution

A five-component variable system with movable lens groups and a large air space for illumination, allowing the object to be imaged into infinity, increasing the object-side numerical aperture and resolving power, while preventing shadows through optimal illumination direction and maintaining constant illuminance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If object details are magnified with existing systems, then magnification is achieved, but illuminance decreases considerably

Engineering Contradiction:

ImprovemagnificationVSAvoidilluminance

Core Design Contradiction:

Measurement precisionVSIllumination intensity

Solution Approach 1:

The patent employs a dynamic variation system with five movable lens groups that can adjust their positions along the optical axis to achieve variable magnification. The system dynamically reconfigures the optical path to maintain constant illuminance while changing magnification levels, resolving the contradiction between magnification and illuminance loss.

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The patent changes the optical parameters by introducing a variation system with five lens groups having specific focal lengths and movable positions. By adjusting the object distance and lens positions, the system achieves variable magnification while maintaining constant illuminance through careful parameter optimization.

Inventive Principle:

Principle #35Parameter changes

2Illumination intensity

If object is illuminated sideways, then illumination is provided, but shadows are formed in the object field

Engineering Contradiction:

ImproveilluminationVSAvoidshadows

Core Design Contradiction:

Illumination intensityVSObject-affected harmful factors

Solution Approach 1:

Instead of illuminating the object from the side, the patent positions the light source to illuminate the object from the direction of observation (effectively 'from behind' the observer). This inverted illumination approach eliminates shadows in the object field while maintaining adequate illumination intensity.

Inventive Principle:

Principle #13The other way round (Inversion)

Solution Approach 2:

The patent introduces an intermediary illumination system with specific lens groups that redirect light to illuminate the object from the observation direction. This intermediary approach allows controlled illumination that avoids shadow formation while maintaining image quality.

Inventive Principle:

Principle #24Intermediary (Mediator)

3Measurement precision

If numerical aperture is not increased during magnification, then empty magnification is achieved, but resolution does not improve

Engineering Contradiction:

ImprovemagnificationVSAvoidresolution

Core Design Contradiction:

Measurement precisionVSManufacturing precision

Solution Approach 1:

The variation system dynamically adjusts the numerical aperture alongside magnification changes. By coordinating the movement of multiple lens groups, the system achieves true magnification with increasing numerical aperture, thereby improving resolution rather than achieving empty magnification.

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The patent merges the functions of magnification and numerical aperture increase into a single coordinated operation. The five lens groups work together to simultaneously achieve variable magnification and maintain/increase numerical aperture, eliminating the separation between these functions found in conventional systems.

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

The system achieves variable imaging scales with increased resolution and illuminance, effectively addressing the limitations of prior art by balancing technical outlay and maintaining constant image-side illuminance, even at higher magnifications.

Implementation Method 1

a variation system consisting of five lens groups (1LG1 to 1LG5), a lens group (1LG6) downstream of the variation system for imaging the object from infinity into the image plane

Methodology Applied

Scientific EffectRefraction: Refraction

Implementation Method 2

a light source (1L) for generating light in order to illuminate the object

Methodology Applied

Scientific EffectLight emission: Light

Data Source

PatentUS9151936B2Optical inspection system with a variation system consisting of five lens groups for imaging an object into infinity

Publication Date: 2015.10.06 CARL ZEISS MICROSCOPY GMBH

AI summary

The invention relates to an optical inspecting system designed to image an object to be inspected with a variable imaging scale, comprising a variation system for imaging the object into infinity, a lens group downstream of the variation system for imaging the object from infinity into the image plane of the whole system, and a light source for generating light in order to illuminate the object, means for imaging the illuminating light into the exit pupil of the variation system being provided in the airspace between the fifth lens group and the subsequent lens group. Of the five lens groups of the variation system, the first, second, and fourth lens groups, when seen in the imaging direction, are arranged in a movable manner in the direction of the optical axis, whereas the third and fifth lens groups are not movable.