Ceramic Ball Surface Inspection Using Multi-Angle Rotation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing methods for inspecting surface defects in ceramic sintered bodies with a band-shaped portion around a spherical surface portion face challenges such as reduced precision due to shadow casting and fluctuating oil conditions, leading to inaccurate defect detection and low yield rates.
Innovation Solution
A surface defect inspection method involving an arrangement step, photographing control step, and detection step, where the ceramic sintered body is arranged on a member with spherical members, rotated to capture images from multiple directions, and defects are detected based on these images using a line sensor camera.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If reflected light inspection is used, then inspection can be performed on ceramic sintered bodies, but the band-shaped portion casts a shadow causing reduced inspection precision
Solution Approach 1:
The patent transitions from 2D reflected light inspection to 3D shape measurement by capturing depth information. The shape measurement device measures the actual three-dimensional shape of the ceramic sintered body, allowing the band-shaped portion to be distinguished from surface defects through its characteristic 3D geometry, thereby eliminating the shadow problem that plagues 2D inspection methods.
Solution Approach 2:
The patent replaces the optical reflected light inspection system with a shape measurement system that captures actual physical geometry data. This substitution enables differentiation between the band-shaped portion (a known geometric feature) and actual surface defects, resolving the shadow interference issue inherent in optical methods.
2Measurement precision
If reflected light inspection is used, then inspection can be performed, but inspection precision lowers when ball size changes due to contrast changes
Solution Approach 1:
The patent changes the measurement parameter from optical contrast (which varies with ball size) to three-dimensional shape data (which is scale-invariant). The shape measurement device captures geometric information that can be normalized and compared across different ball sizes, eliminating the contrast dependency issue.
Solution Approach 2:
The patent replaces the optical inspection system with a shape measurement system that is inherently independent of ball size. The 3D shape data can be scaled and compared universally, providing consistent inspection precision across different ceramic sintered body sizes without the contrast variation problems of optical methods.
3Measurement precision
If image measurement in oil is used, then inspection precision can be maintained when ball size changes, but image quality becomes unstable due to oil fluctuation
Solution Approach 1:
The patent eliminates the oil intermediary medium entirely by using direct air-based shape measurement. This removes the source of image quality instability (oil fluctuation) while maintaining measurement precision through three-dimensional shape capture, which is inherently more stable and repeatable than optical imaging through fluid media.
4Measurement precision
If visual observation by person is used, then inspection can be performed, but human errors occur and yield rate is influenced
Solution Approach 1:
The patent replaces human visual observation with an automated shape measurement device that captures objective three-dimensional data. This eliminates human error and subjectivity, providing consistent, repeatable inspection results that directly improve yield rate by ensuring uniform quality standards are applied to every ceramic sintered body.
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 method enhances inspection precision, allowing detection of defects as small as 0.5 mm or smaller, improves yield rates by reducing human error, and optimizes inspection time to two seconds or less per piece, while being versatile for various ceramic sintered body sizes and materials.
Implementation Method 1
The photographing control step rotates the ceramic sintered body arranged on the arrangement member in response to rotation of the plurality of spherical members
Data Source
Figure 1~2
Figure 3(a)~3(c)
Figure 4~5
AI summary
A surface defect inspection method for a ceramic sintered body including a spherical surface portion according to an embodiment includes: an arrangement step; a photographing control step; and a detection step. The arrangement step arranges the ceramic sintered body on an arrangement member having a plurality of spherical members. The photographing control step rotates the ceramic sintered body arranged on the arrangement member in response to rotation of the plurality of spherical members, photographs the ceramic sintered body, which is arranged on the arrangement member, from a plurality of directions, and acquires a plurality of images. The detection step detects a surface defect of the ceramic sintered body based on the plurality of images.