| 摘要 |
PROBLEM TO BE SOLVED: To obtain a method and an apparatus in which the existance and the shape of an uneven part can be measured with good accuracy and in which a wide range can be measured at one time by a method wherein reflected light in a region to be measured is image-formed by an object-side telecentric optical system, luminance data is acquired and processed and a bright part and a dark part are recognized. SOLUTION: A light irradiation means 110 is constituted of a light source 111, of an aperture 112, of a semitransparent mirror 113 and of a collimating lens 114. An object-side telecentric optical system 300 is provided with an image-formation lens system 320, with a light limitation means 310 such as an aperture diaphragm or an aperture and with an aperture-angle variable means 330. When illumination light is a nearly complete parallel luminous flux and when the aperture diameter of the light limitation means 310 is very small, an image which is formed by the object-side telecentric optical system 300 becomes a bright and dark two-gradation image according to an incidence angle in every point in a region to be measured. An imaging part 400 images the formed image, and luminance data on every point in every pixel, i.e., the region to be measured is acquired. A processing part 510 finds the existence of an uneven part and the shape of the uneven part in the region, to be measured, on the basis of the luminance data. |
