THREE-DIMENSIONAL SHAPE MEASURING METHOD AND THREE-DIMENSIONAL SHAPE MEASURING DEVICE

PROBLEM TO BE SOLVED: To provide a three-dimensional shape measuring method extracting surely a light cutting line in an imaged image of the light cutting line regardless of magnitude of a reflectivity of a measuring object surface, brightness of illumination in a measuring environment or the like, and coping with robust automatic control relative to exposure. SOLUTION: This three-dimensional shape measuring method by an optical cutting method is described as follows: two-dimensional images in a plurality of exposure states including a critical state on the under side and a critical state on the over side are acquired; a brightness volume V which is an integrated value of brightness values on image data is calculated relative to each of the plurality of acquired two-dimensional images; a mean value of each calculated brightness volume V relative to the plurality of two-dimensional images is set as a target brightness volume Vrefin a control of exposure; and exposure is controlled based on a difference determined by comparing an input signal based on the target brightness volume Vrefwith a feedback signal based on a measured brightness volume Vmeanscalculated relative to a two-dimensional image corresponding to each scanning position to a work of slit light. COPYRIGHT: (C)2010,JPO&INPIT