Movable Light Selection Aperture for Multi-Angle Optical Inspection
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Solution Overview
Problem
Existing contactless inspection methods struggle to acquire multiple images of an object's surface or interior with varying light beam directions, limiting the detection of minute surface asperities and scattering angle distribution.
Innovation Solution
An optical inspection apparatus with a movable first light selection aperture having two distinct regions that can switch between different light selection paths, allowing the acquisition of multiple images by altering the light beam direction and intensity information, facilitated by a controller and aperture movement mechanism.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a conventional inspection method using a diffraction grating or wavelength filter is used to specify color and identify light beam direction, then the light beam direction can be identified, but multiple images with varying light beam directions cannot be acquired
Solution Approach 1:
The light selection aperture is made movable rather than fixed, allowing it to selectively pass light beams from different directions. The aperture can be positioned at multiple locations along the optical axis and rotated about the optical axis, enabling dynamic selection of light beam directions for imaging. This dynamic positioning mechanism resolves the contradiction by providing multiple imaging capabilities without requiring multiple fixed inspection systems.
Solution Approach 2:
The patent introduces rotational movement of the light selection aperture about the optical axis as an additional degree of freedom. By rotating the aperture, light beams from different angular directions can be selected and directed to the image sensor. This rotational dimension enables acquisition of multiple images with varying light beam directions, resolving the limitation of conventional fixed aperture systems.
2Measurement precision
If the light selection aperture is fixed, then the device structure is simple, but the detection of minute surface asperities and scattering angle distribution is limited
Solution Approach 1:
The light selection aperture is equipped with movement mechanisms that allow it to be dynamically positioned at different locations along the optical axis and rotated about the optical axis. This dynamic positioning enables selective imaging of light beams from different directions, which is essential for detecting minute surface asperities and measuring scattering angle distribution with high precision.
Solution Approach 2:
The patent changes the positional parameters of the light selection aperture, including its distance from the object and its rotational angle about the optical axis. By varying these parameters, the system can capture images under different lighting conditions and angles, thereby improving the precision of surface asperity detection and scattering angle measurement.
3Loss of information
If multiple inspection systems are used to acquire images from different light beam directions, then comprehensive surface information can be obtained, but the device complexity and cost increase
Solution Approach 1:
A single light selection aperture is designed to perform multiple functions by being positioned at different locations and rotated to different angles. This universal aperture can select light beams from various directions and direct them to the image sensor, enabling one inspection system to acquire comprehensive surface information that would otherwise require multiple separate systems.
Solution Approach 2:
The patent merges the functions of multiple inspection systems into a single integrated system. By combining the light selection aperture with movable and rotational capabilities, the system consolidates multiple imaging functions into one device, thereby reducing overall complexity and cost while maintaining the ability to acquire comprehensive surface information from different light beam directions.
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 the capture of multiple images with varying light beam directions, enhancing the detection of minute surface asperities and scattering angle distribution, thereby improving the accuracy of optical inspections.
Implementation Method 1
an image-forming optical element 22 having an imaging optical axis C, an image sensor 24 having a light-receiving surface 24a intersecting with the imaging optical axis C of the image-forming optical element 22
Implementation Method 2
a first light selection aperture 26 that includes a first light selection region 32 and a second light selection region 34... the first light selection region 32 and the second light selection region 34 to selectively pass light in different directions
Data Source
AI summary
According to an embodiment, an optical inspection apparatus includes: an image-forming optical element with an imaging optical axis; an image sensor having a light-receiving surface; and a movable first light selection aperture that is arranged on or near a focal plane of the image-forming optical element. The first light selection aperture includes a first light selection region and a second light selection region that selectively pass light in different directions from an object. When the first light selection region moves to a position, the image sensor acquires a first image of the object incident on the light-receiving surface through the image-forming optical element and the first light selection region. When the second light selection region moves to a position, the image sensor acquires a second image of the object incident on the light-receiving surface through the image-forming optical element and the second light selection region.