Patent ID: 8351709
Filing Date: 2013-01-08
Classification: G01B

Abstract:
1. A projection height measuring method for measuring a height of a projection having a conical shape formed on a surface of a workpiece, comprising: an imaging step for imaging, by a processing unit, an area on the surface of the workpiece including the projection, which is an object to be measured, at an angle of depression; a projection area extracting step for extracting, by the processing unit, a projection area from an image, by classifying an area in the image into a bright area, a dark area and an intermediate area based on brightness values in the image imaged by the imaging step, and out of the bright area, the dark area and the intermediate area, regarding an area composed of the bright area and the dark area as the projection area corresponding to the projection and regarding an area composed of the intermediate area as a work area corresponding to the workpiece; a diameter/generatrix measuring step for measuring, by the processing unit, a length of a diameter corresponding portion corresponding to a bottom surface diameter portion of the projection area extracted by the projection area extracting step and a length of a generatrix corresponding portion corresponding to a generatrix portion of the projection area; and a height calculating step for calculating, by the processing unit, the height of the projection based on the length of the diameter corresponding portion, the length of the generatrix corresponding portion and the angle of depression.