Abstract: A three-dimensional shape measuring method and a three-dimensional shape measuring apparatus of excellent measurement accuracy. An optical system comprises a light source, a pattern forming unit which is disposed on the optical axis of the light source to form slit light from the light from the light source, and a projection lens to collect the slit light on the object for measurement. An asymmetric diaphragm having an aperture in which the size in the direction perpendicular to the slit direction is smaller than the size in the slit direction is provided in order to stop the slit light. An image pickup optical system is provided to measure the three-dimensional shape of the object for measurement on the basis of the slit light reflected from the object for measurement.

Abstract: A three-dimensional shape measuring method and a three-dimensional shape measuring apparatus of excellent measurement accuracy. An optical system comprises a light source, a pattern forming unit which is disposed on the optical axis of the light source to form slit light from the light from the light source, and a projection lens to collect the slit light on the object for measurement. An asymmetric diaphragm having an aperture in which the size in the direction perpendicular to the slit direction is smaller than the size in the slit direction is provided in order to stop the slit light. An image pickup optical system is provided to measure the three-dimensional shape of the object for measurement on the basis of the slit light reflected from the object for measurement.

Abstract: A displacement measuring method and apparatus can measure positions and displacements of measurement objects with high precision without regard to surface roughness. Optical beams emitted from a light source are converged through an objective lens, are incident on a surface of the measurement object, are reflected off the surface of the measurement object, and are received by an optical detector. In measurement of the surface of the measurement object, optical-intensity curves are defined while the objective lens is being shifted in the optical-axis direction. According to optical-intensity curves thus defined, a threshold Pth is defined, a center of gravity of a graph region surrounded by the optical-intensity curve is defined, and the focal point of the objective lens, when positioned at the center of gravity, is determined to be the position of a surface of the measurement object.