Interference Fringe Projection Optics With Telecentric Correction
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Solution Overview
Problem
Existing interference fringe projection optical systems suffer from distortion when reduced in size due to non-parallel principal rays, leading to increased wavefront aberration and reduced contrast in the interference fringe.
Innovation Solution
The system employs a light source with two light emitting units, a light distribution correction lens, and lens groups with specific focal length and positional relationships to maintain telecentricity and suppress distortion, ensuring parallel luminous fluxes and high contrast.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If the optical system is reduced in size, then the device becomes more compact, but the principal rays cannot be parallel causing interference fringe distortion
Solution Approach 1:
A light distribution correction lens is introduced as an intermediary component between the light source and the lens groups. This correction lens specifically corrects the light distribution to ensure parallel principal rays, thereby eliminating interference fringe distortion while enabling miniaturization of the overall optical system.
Solution Approach 2:
The patent optimizes specific parameters including the focal lengths of the lens groups (f1 and f2) and their spacing (xd) to satisfy the telecentricity condition xd/(f1+f2)=1. By carefully controlling these parameters, the system maintains parallel principal rays even in a compact configuration, preventing wavefront aberration and interference fringe distortion.
2Volume of moving object
If the principal rays are not parallel, then the system can be smaller, but wavefront aberration increases reducing interference fringe contrast
Solution Approach 1:
The light distribution correction lens serves as a mediator that specifically addresses the wavefront aberration issue. It corrects the light distribution from the light source to ensure parallel principal rays, thereby maintaining high interference fringe contrast while allowing for a compact system design.
Solution Approach 2:
By optimizing the focal lengths f1 and f2 of the lens groups and their spacing xd to satisfy the telecentricity condition, the system maintains parallel principal rays. This parameter optimization ensures minimal wavefront aberration and high interference fringe contrast in a miniaturized configuration.
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 configuration maintains interference fringe quality and contrast even when the optical system is miniaturized, enhancing robustness against wavefront aberration and reducing system size.
Implementation Method 1
a light distribution correction lens on which a luminous flux emitted from the light emitting unit is incident
Implementation Method 2
an incidence-side lens group which is arranged on a side on which a luminous flux emitted from the light distribution correction lens is incident, and an emission-side lens group which is arranged on a side on which the interference fringe is projected
Data Source
AI summary
A light distribution correction lens on which a luminous flux emitted from the light emitting unit is incident and which is a single lens having a positive power is arranged at a position at which a distance to the light emitting unit is smaller than a distance to an incidence-side lens group.A focal length of the incidence-side lens group is denoted by f1 and a focal length of the emission-side lens group is denoted by f2, f1/f2>3 is satisfied, and each of the incidence-side lens group and the emission-side lens group has positive refractive power, and when a distance from an emission-side principal point of the incidence-side lens group to an incidence-side principal point of the emission-side lens group is denoted by xd, xd<f1+f2 is satisfied.