Optical Inspection Apparatus for Single-Shot BRDF Capture
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional optical inspection technologies face challenges in simultaneously acquiring scattering light beams with various angles, requiring multiple image captures and struggling to distinguish between different scattering angles, which limits the accuracy in determining surface properties and materials.
Innovation Solution
An optical inspection apparatus employing a first and second illuminator emitting light beams of different wavelengths, with band-pass filters and a scattering light selector to pass and block specific wavelength regions, allowing simultaneous acquisition of scattering light beams with distinct angles, enabling the capture of Bidirectional Reflectance Distribution Function (BRDF) in a single shot.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conventional optical inspection methods are used to capture scattering light, then multiple image captures are required to acquire scattering light beams with various angles, but this increases the time required for inspection and reduces productivity
Solution Approach 1:
The patent divides the aperture into multiple wavelength-selective regions, each passing light of a specific wavelength range. This segmentation allows different scattering angles to be captured simultaneously through the same optical path, eliminating the need for multiple sequential image captures while maintaining measurement precision for surface properties.
Solution Approach 2:
The patent introduces a wavelength dimension to the aperture, transforming it from a simple spatial opening into a wavelength-selective element. By incorporating band-pass filters with different wavelength characteristics in different regions of the aperture, the system can distinguish and capture scattering light from various angles simultaneously, converting a temporal sequencing problem into a spectral separation problem.
2Measurement precision
If conventional optical inspection methods are used, then multiple image captures are required to distinguish different scattering angles, but this increases device complexity and operation time
Solution Approach 1:
The patent merges the functions of multiple apertures or multiple imaging paths into a single aperture with wavelength-selective regions. Instead of requiring separate optical paths or multiple cameras for different scattering angles, the invention combines all angle-discrimination functions into one aperture structure with spatially distributed wavelength filters, simplifying the overall device configuration.
Solution Approach 2:
The patent introduces band-pass filters as intermediary elements between the object and the imaging sensor. These filters act as mediators that selectively transmit specific wavelength ranges corresponding to different scattering angles, enabling angle discrimination without requiring complex mechanical or optical switching mechanisms.
3Loss of information
If conventional optical inspection methods are used, then multiple sequential captures are required, but this increases the time required for acquiring complete scattering light information
Solution Approach 1:
The patent enables continuous acquisition of scattering light information from various angles simultaneously through a single aperture structure. Instead of sequentially capturing different angles at different times, the wavelength-selective aperture allows all angular information to be captured in one continuous imaging operation, eliminating time losses between sequential captures.
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 simultaneous acquisition of scattering light beams with various angles, improving the accuracy in determining surface properties and materials by capturing BRDF with greater precision and efficiency compared to conventional methods.
Implementation Method 1
a scattering light selector configured to emit passing light beams of at least two mutually different wavelength regions
Implementation Method 2
The first light beam reflected by an object is incident on the image-forming optical system
Implementation Method 3
an image-forming optical system on which the first light beam reflected by an object is incident
Data Source
AI summary
According to one embodiment, an optical inspection apparatus includes a first illuminator, an image-forming optical system, a scattering light selector, and an imaging element. The first illuminator is configured to emit a first light beam. The first light beam reflected by an object is incident on the image-forming optical system. The scattering light selector is configured to emit passing light beams of at least two mutually different wavelength regions, at the same time as the first light beam passes, a wavelength spectrum of at least one of the passing light beams being different from a wavelength spectrum of the reflected first light beam. The passing light beams simultaneously form an image on the imaging element.