Telecentric Lens With Folded Optical Path

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Solution Overview

Problem

Telecentric lenses used in artificial vision systems face challenges in reducing overall dimensions without increasing the number of optical elements, which complicates manufacturing and increases costs, while also compromising optical performance as the size of the observed object increases.

Innovation Solution

The integration of reflective or semi-reflective optical elements between the front optical group and the lens aperture, causing at least a part of the rays to undergo multiple reflections, reduces the distance between optical groups and overall lens length without increasing the number of optical elements, thereby maintaining optical performance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Length of moving object

If the focal length f1 is reduced to decrease the overall length of the telecentric lens, then the lens becomes more compact, but the number of optical components must increase which complicates manufacturing and increases costs

Engineering Contradiction:
Improveoverall length of telecentric lensVSAvoidnumber of optical components
Core Design Contradiction:
Length of moving objectVSDevice complexity

Solution Approach 1:

The patent introduces a reflective element that redirects the optical path at an angle, effectively utilizing spatial dimension to fold the optical path. This allows the light to travel a longer effective distance through the optical components while maintaining a compact physical footprint, thereby reducing the overall lens length without increasing the number of optical components

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

Solution Approach 2:

The reflective element is integrated within the existing optical structure, nesting the reflection function within the lens assembly. This allows the optical path to be folded back on itself, enabling multiple optical components to be arranged in a more compact configuration without increasing device complexity

Inventive Principle:
Principle #7Nested doll (Nesting)

2Adaptability or versatility

If the diameter d1 and focal length f1 are increased to observe larger objects, then the observation capability is improved, but the lens dimensions and complexity increase significantly

Engineering Contradiction:
Improveobject size observation capabilityVSAvoidlens structure complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

By introducing a reflective element that folds the optical path, the patent enables larger focal lengths and object observation capabilities while maintaining a compact physical structure. The reflected path allows light from larger objects to be directed through the optical components without requiring a proportionally larger physical lens assembly

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

Solution Approach 2:

The optical system is segmented into distinct functional groups (front optical group, reflective element, rear optical group) that can be independently optimized. This segmentation allows the front optical group to handle large object collection while the reflective element and rear group manage the optical path folding, reducing overall structural complexity

Inventive Principle:
Principle #1Segmentation

3Length of moving object

If reflective elements are added to reduce lens length, then the overall dimensions are reduced, but the number of optical components increases

Engineering Contradiction:
Improvedistance between optical groupsVSAvoidnumber of optical components
Core Design Contradiction:
Length of moving objectVSDevice complexity

Solution Approach 1:

The reflective element serves multiple functions simultaneously: it folds the optical path to reduce physical length, maintains the telecentric optical properties, and enables compact arrangement of optical components. This multi-functionality justifies the addition of the reflective element without proportionally increasing device complexity

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

Solution Approach 2:

The reflective element acts as an intermediary component that mediates between the front and rear optical groups, redirecting light paths to achieve compact dimensions while maintaining optical performance. This intermediary function allows the system to achieve space reduction without requiring fundamental redesign of the optical groups themselves

Inventive Principle:
Principle #24Intermediary (Mediator)

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 approach results in a more compact telecentric lens design that maintains optical performance and reduces overall dimensions, addressing the complexity and cost issues associated with larger objects while minimizing chromatic aberrations and optical component power.

Implementation Method 1

The integration of reflective or semi-reflective optical elements between the front optical group and the lens aperture, causing at least a part of the rays to undergo multiple reflections

Methodology Applied
Scientific EffectReflection: Reflection

Data Source

PatentEP3271770B1Telecentric lens
Publication Date: 2023.09.27 OPTO ENG
  • EP3271770B1 patent drawingFigure 1
  • EP3271770B1 patent drawingFigure 1a~1b
  • EP3271770B1 patent drawingFigure 2

AI summary

A telecentric lens comprises a front optical group (20) defining a front optical axis (k), at least a first rear optical group (40), defining a rear optical axis (k'), and at least one lens aperture (30) positioned between the front optical group 20 and a respective rear optical group. Between the front optical group (20) and the lens aperture (30) are inserted at least two reflective or semi-reflective elements arranged in such a way that at least a part of the rays coming from the front optical group undergoes at least one double reflection before reaching the rear optical group (40).