Patent Number: 6,490,541

Title: Method and apparatus for visual measurement

Abstract: An apparatus for visual measurement is provided, which can measure a plurality of portions on a work at a high speed. An image pick-up system (3), including an optical system (5, 6) and a CCD camera (4), picks up an image of a work (2) to obtain image data. The image pick-up system (3) is driven in the Z axial direction by a driving motor (7). A displacement of the image pick-up system (3) in the Z axial direction is measured by a scale counter (8). A computer (10) reads image data from the CCD camera (4) and a Z value from the scale counter (8) into respective memories (11, 9) with a constant time interval. A contrast arithmetic unit (12) computes a contrast value at each of a plurality of different regions of image data obtained at each z axial position by the image pick-up system (3). It determines a measure for the each region based on the position of the image pick-up system (3) in the z axial direction when the contrast value comes to the maximum in the each region.

Inventors: Ariga; Kozo (Kawasaki, JP), Komatsu; Koichi (Kawasaki, JP)

Assignee: Mitutoyo Corporation

International Classification: B23Q 17/24 (20060101); G01B 11/02 (20060101); H04N 007/18 ()

Expiration Date: 12/03/2011