Outer Dimension Measuring Apparatus for Thin Wire
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional outer dimension measuring apparatuses face difficulties in accurately measuring thin wire members with diameters less than 10 μm due to issues like narrow laser beam blocking and reduced light contrast caused by diffraction, making it challenging to detect the blocked light state or region.
Innovation Solution
An outer dimension measuring apparatus that includes a light source, an optical system, a reflecting portion, and a detection system to detect the intensity of reflected light at specific focus positions, allowing for accurate calculation of the object's dimension using the first and second focus positions and the reflecting portion's position, even for extremely narrow diameters, by employing a configuration with axial chromatic aberration and broadband light to enhance measurement precision.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a laser scanning micrometer is used to measure thin wire members, then the measurement can be conducted non-contact, but the wire member diameter is narrower than the diameter of the scanning laser beam making it difficult to detect the blocked light state
Solution Approach 1:
The invention segments the measurement process into two distinct light path measurements: one for the front surface and one for the rear surface. By using separate focus positions (first focus position for front surface, second focus position for rear surface) and detecting reflected light intensity peaks at each position, the system can independently measure each surface's contribution, thereby resolving the detection difficulty for thin wire members smaller than the beam diameter.
2Measurement precision
If an image sensor micrometer is used to measure thin wire members, then the measurement can be conducted non-contact, but detection of the blocked light region is difficult due to reduced contrast of the shadow caused by diffraction
Solution Approach 1:
Instead of directly measuring the shadow or blocked light region (which has reduced contrast due to diffraction), the invention inverts the approach by measuring the reflected light intensity. By detecting the peak reflected light intensity at specific focus positions for the front and rear surfaces, the system obtains clear measurement signals that are not degraded by diffraction effects, thereby solving the low contrast problem.
3Adaptability or versatility
If conventional measurement methods are used for thin wire members with diameter less than 10 μm, then the existing apparatus can be used, but the measurement accuracy is insufficient due to the narrow diameter being smaller than the beam diameter
Solution Approach 1:
The invention transitions from a single-dimensional measurement approach (single beam diameter comparison) to a two-dimensional approach by introducing multiple focus positions along the optical axis. By measuring at different axial positions (first focus position and second focus position corresponding to front and rear surfaces), the system creates an additional measurement dimension that enables accurate measurement of thin wire members regardless of their diameter being smaller than the beam diameter.
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 high-accuracy measurement of thin wire members by detecting the first and second focus positions simultaneously, overcoming the limitations of conventional methods and maintaining a small measurement beam spot diameter, thus effectively measuring objects with diameters as low as 10 μm or less.
Implementation Method 1
an optical system for focusing the light emitted from the light source onto an optical axis
Implementation Method 2
a reflecting portion for reflecting the light focused by the optical system
Implementation Method 3
a detection portion for detecting an intensity of the reflected light according to a focus position on the optical axis
Data Source
AI summary
An outer dimension measuring apparatus includes a light source; an optical system focusing the light emitted from the light source onto an optical axis; a reflector reflecting the focused light; a detector detecting an intensity of the reflected light; and a calculator calculating an outer dimension of a measured object using a first focus position, a second focus position, and a position of the reflector on the optical axis, the first focus position lying on the optical axis where a peak in reflected light intensity is detected by the detector for light reflected by a first surface, and the second focus position lying on the optical axis where a peak in reflected light intensity is detected by the detector for light that has been reflected by the reflector and emitted at a second surface.