Optical Inspection With Multi-Angle Illumination for Surface Estimation
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Solution Overview
Problem
Conventional optical inspection methods rely on a one-to-one correspondence between light beam direction and wavelength spectrum, limiting the accuracy and efficiency of acquiring information about object surfaces or interiors.
Innovation Solution
An optical inspection apparatus and method that utilizes multiple solid angles of illumination with a single wavelength spectrum to acquire information by combining multiple captured images, improving accuracy through recursive use of overlapping and distinct solid angles.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a one-to-one correspondence between light beam direction and wavelength spectrum is used, then the inspection method is simple, but the accuracy and efficiency of acquiring object information is limited
Solution Approach 1:
The illumination is segmented into multiple solid angles (first solid angle and second solid angle) with different wavelength spectra (first wavelength spectrum and second wavelength spectrum). This segmentation allows independent control of illumination parameters to improve measurement precision without requiring a completely complex system, as each segment can be optimized separately.
Solution Approach 2:
The patent transitions from a one-to-one correspondence (two-dimensional mapping) to a many-to-one correspondence by introducing a third dimension (wavelength spectrum as an additional parameter). Multiple light beams at different solid angles can share the same wavelength spectrum, creating a three-dimensional illumination space that enhances information acquisition capability.
2Measurement precision
If multiple solid angles with different wavelength spectra are used, then the accuracy of estimating inclination angles is improved, but the number of illumination configurations increases
Solution Approach 1:
The illumination portion is designed to be universal by capable of emitting light beam fluxes at multiple solid angles with different wavelength spectra using a single integrated system. This multi-functionality allows the system to acquire multiple captured images with different illumination conditions without requiring separate illumination devices for each configuration, thereby improving measurement precision while controlling device complexity.
3Measurement precision
If multiple captured images are combined to acquire information, then the accuracy of surface property estimation is improved, but the processing time increases
Solution Approach 1:
The system performs preliminary actions by acquiring multiple captured images with different illumination configurations before final processing. By pre-acquiring images at multiple solid angles and wavelength spectra, the system prepares data that can be efficiently combined later, reducing the overall processing time while maintaining high accuracy in surface property estimation.
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
Enhances the accuracy of estimating inclination angles and surface properties by combining captured images, allowing for detailed information acquisition with a single wavelength spectrum, even on rough surfaces.
Implementation Method 1
acquire at least a first captured image of the object by causing the imaging portion to acquire light reflected from the object
Implementation Method 2
an imaging portion configured to acquire light reflected from the object irradiated by the illumination portion
Data Source
AI summary
According to an embodiment, an optical inspection apparatus includes an illumination portion, an imaging portion, and a processor. The illumination portion is configured to irradiate a first object point of an object with a light beam flux at one or more solid angles. The imaging portion is configured to acquire an image of the object according to illumination with the light beam flux. The processor causes the first object point to be irradiated with a light beam flux at a first solid angle by first illumination light, acquires a first captured image of the object with the first illumination light, causes the first object point to be irradiated with light beam fluxes at the third and fourth solid angles by second illumination light, acquires a second captured image of the object with the second illumination light, and acquires information regarding the object by the first and second captured images.