Ceramic body defect inspecting device and defect inspecting method

Abstract

The invention provides a ceramic body defect inspecting device and a defect inspecting method. Around an image capturing unit which captures images of an inspection target region from a normal line direction thereof, a plurality of unit lights, which are at equiangular intervals from one another, and each of which radiates illuminating light obliquely, with the same radiation angle, toward the inspection target region from a different radiation direction, are successively turned on and off. Each time each of the plurality of unit lights is turned on, the image generating unit captures an imageof the inspection target region, thereby generating a plurality of sets of image-capture data. A determination image generating unit generates minimum brightness image data in which the minimum valueof the brightness at the same pixel position from among the plurality of sets of image-capture data is set as a brightness value at said pixel position, and generates determination image data on thebasis of the minimum brightness image data. A defect determining unit determines the presence or absence of a defect on the basis of the determination image data.

Description

Technical field [0001] The present invention relates to a device and method for detecting whether there are defects on the outer surface of a ceramic body, and in particular to a device and method for detecting the end surface of a honeycomb structure. Background technique [0002] As a filter for trapping particulate matter contained in exhaust gas from internal combustion engines, boilers, etc., and a catalyst carrier for exhaust gas purification catalysts, honeycomb structures that are porous bodies (ceramic bodies) made of ceramics are widely used. The honeycomb structure has a plurality of cells divided by partition walls each along the axial direction of the structure in the inside surrounded by the cylindrical outer surface (outer wall). The ceramic honeycomb structure is excellent in heat resistance, thermal shock resistance, and oxidation resistance, and therefore it is widely used in other applications than the above-mentioned applications. [0003] In such a honeycomb s...

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Problems solved by technology

[0009] For example, if oblique light illumination as disclosed in Patent Document 2 is used for defect inspection, there is a problem that although it is known that defective parts such as notches and pits tend to become dark parts (shadows), on the other hand, in normal Concave and convex parts are also prone to shadows, so when detecting defects based on the presence or absence of dark parts, there is a high possibility that normal concave and convex parts will be erroneously detected as defects

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