Patent ID: 6330066
Filing Date: 2001-12-11
Classification: G01B

Abstract:
A height measuring apparatus comprising:an imaging device that is movable in a Z direction that is perpendicular to an object, for imaging the object;an adjustable moving apparatus that moves the imaging means in the Z direction; anda controlling device that measures a height of the object by causing the imaging device to image the object at a predetermined number of positions in a Z direction sequentially, while causing the moving apparatus to move the imaging device in the Z direction by a very small distance at a time, wherein when the imaging device images the object it:a) acquires a pixel in an image captured at a first predetermined position in the Z direction and determines whether the acquired pixel is a final pixel in said image,b) if the acquired pixel is not a final pixel, calculates focus values of the acquired pixel through image processing based on respective imaged pictures, and detects a focus position from a Z-direction variation of the focus values,c) if the acquired pixel is a final pixel in said image, it moves to another predetermined position until images are stored from each of said predetermined positions.