Patent ID: 9003871
Filing Date: 2015-04-14
Classification: G01N

Abstract:
1. A hardness tester which applies a predetermined test force with an indenter to a surface of a sample placed on a sample support to form an indentation, and measures a dimension of the indentation to measure hardness of the sample, the hardness tester comprising: an image pickup control section which controls an image pickup section to pick up an image of the surface of the sample, to obtain picked-up image data of the surface of the sample; an indentation region extraction section which (i) binarizes the picked-up image data, (ii) erodes and dilates the binarized image data, and (iii) performs distance transform on the eroded-and-dilated image data, to extract a closed region corresponding to a shape of the indenter using the distance-transformed image data; an indentation apex extraction section which extracts an indentation-measurement-use apex on the basis of the extracted closed region, the apex being used to measure the dimension of the indentation; and a hardness calculation section which calculates the hardness of the sample on the basis of the extracted apex, wherein the indentation region extraction section determines on the basis of the binarized image data whether an indentation region candidate is extracted, and when determining that the indentation region candidate is not extracted, (i) obtains curvature image data on the basis of a brightness value of the picked-up image data, (ii) binarizes the obtained curvature image data, and (iii) erodes and dilates the binarized curvature image data.