Measuring Head Optical Path Splitting for Tilt Shift Eccentricity
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Solution Overview
Problem
Existing eccentricity measuring devices face challenges in simultaneously measuring tilt and shift with high precision over a wide measurement range, particularly when dealing with subjects that are long in the measurement axis direction, as they often require separate paths for image formation and detection, leading to limitations in measurement accuracy and range.
Innovation Solution
A measuring head comprising a light source unit, two image pickup elements, an objective optical system, and an optical path splitting element, where the optical paths are configured to allow simultaneous measurement of tilt and shift by forming images of the light source and the subject on different image pickup elements, with the optical path splitting element positioned at the intersection of the paths, enabling precise detection of displacement and angle deviations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Length of moving object
If separate paths are used for image formation and detection, then measurement range is improved, but measurement precision deteriorates
Solution Approach 1:
The patent merges the image formation path and detection path into a single integrated optical path. The image pickup element directly captures images formed by the objective optical system, eliminating the need for separate detection paths. This integration maintains measurement precision while achieving wide measurement range through the movable stage mechanism.
2Device complexity
If single image pickup element is used, then device complexity is reduced, but measurement capability deteriorates
Solution Approach 1:
The patent employs a single image pickup element that performs multiple measurement functions. By moving the stage along the optical axis, the same image pickup element can capture images at different positions, enabling both tilt measurement (through image position) and shift measurement (through image formation), thus achieving multi-functionality without increasing device complexity.
3Length of moving object
If movable stage mechanism is added, then measurement range is improved, but device complexity increases
Solution Approach 1:
The patent segments the measurement function into two parts: the optical system remains fixed while the stage with the subject is movable. This segmentation allows the measurement range to be extended by moving the stage along the optical axis, while the core optical components maintain their precision positions, thereby managing device complexity effectively.
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 allows for accurate and simultaneous measurement of tilt and shift over a wide measurement range, enhancing the measurement range in the measurement axis direction and improving the detection of displacement and angle deviations, even for subjects that are long in the measurement axis.
Implementation Method 1
an optical path splitting element (7), wherein a light flux (L1) from the light source unit (3) is incident on a beam splitter (8), part of the light flux (L1) is reflected by the beam splitter (8) and enters the objective optical system (6)
Data Source
AI summary
A measuring head includes a light source unit, a first image pickup element, a second image pickup element, an objective optical system, an optical path splitting element, a common optical path, a first optical path, and a second optical path. The common optical path is located on one side of the optical path splitting element, and the first optical path and a second optical path are located on the other side. The optical path splitting element is disposed at a position where the first optical path and the second optical path intersect. The light source unit and the first image pickup element are disposed at predetermined positions. The second image pickup element is disposed at a position different from the predetermined positions. Each of the predetermined positions is a focal position of the objective optical system or a position conjugate to the focal position of the objective optical system.