Abstract: A phase shift interferometer (4) images a plurality of interference fringe images each generated from interference between a test light reflected at a test surface (3a) and a reference light reflected at an reference surface (5) by emitting a coherent light to both surfaces while varying a phase difference between the test light and the reference light from image to image. A surface shape analyzer (12) analyzes the plurality of interference fringe images taken by the phase shift interferometer (4) to obtain surface shape information of the test surface (3a). A typical plane computer (13) computes a typical plane of the test surface (3a) on the basis of the surface shape information obtained from the surface shape analyzer (12). An oblique angle computer (14) computes an oblique angle of the typical plane computed by the typical plane computer (13) to the reference surface (5).

Abstract: A shape measuring apparatus is provided, which is capable of accurately measuring the shape of an observed surface of an object to be measured and which can be designed to be compact in size and light in weight. An optical reflected image from an observed surface of an object to be measured and an optical reflected image from a reference surface are interfered with each other to generate interference light. The interference light is dispersed into at least three beams, which are shifted in phase by respective predetermined phase shifting amounts. At least three interference fringe images are simultaneously captured by at least one image pickup device which is smaller in number than the interference fringe images.

Abstract: A scanning wide-area surface shape analyzer drastically shortens a time period required for measuring the surface shape of a surface to be inspected. A scanner moves the measuring head in parallel with a flat surface for the measuring head to acquire the measured image data. An attitude-varying mechanism varies the acquisition attitude of the measuring head for acquiring the measured image data. An image processing control device analyzes and calculates the surface shape of an acquisition area corresponding to the acquisition position and in the acquisition attitude. The image processing control device controls driving of the scanner and the attitude-varying mechanism, calculates the next acquisition position by using measured image data acquired at the present acquisition position and in the present acquisition attitude, and calculates an acquisition attitude to be taken at the calculated next acquisition position.

Abstract: There is provided a scanning wide-area surface shape analyzer which is capable of drastically shortening a time period required for measuring the surface shape of an surface to be inspected. A scanner moves the measuring head in parallel with a flat surface such that a scanning reference position thereof set to a point of intersection between an optical axis of the beam and the reference surface in the measuring head sequentially reaches each acquisition position used for the measuring head to acquire the measured image data. An attitude-varying mechanism varies the acquisition attitude of the measuring head for acquiring the measured image data, such that the direction of inclination of a reference axis being a direction vector extending along the optical axis from the scanning reference position is changed relative to the surface to be inspected.

Abstract: A shape measuring apparatus is provided, which is capable of accurately measuring the shape of an observed surface of an object to be measured and which can be designed to be compact in size and light in weight. An optical reflected image from an observed surface of an object to be measured and an optical reflected image from a reference surface are interfered with each other to generate interference light. The interference light is dispersed into at least three beams, which are shifted in phase by respective predetermined phase shifting amounts. At least three interference fringe images are simultaneously captured by at least one image pickup device which is smaller in number than the interference fringe images.

Abstract: A system for compensating for spatial errors of a movable machinery having a three-dimensional spatial mechanism includes a command generator for generating a commanded coordinate value in the space of command; a position controller for operating in response to the commanded coordinates value as an input; a position detector for detecting the operating position set by the position controller on the space of motion as a coordinate value of the space of command; and a spatial error compensating unit for compensating for spatial errors between the space of command and the space of motion contained in the output coordinate value of the position detector, outputting a compensated coordinate value as a measured value and correcting the commanded coordinate value by use of the compensated coordinate value, and the spatial error compensation and the motion control on the compensated space of command can be realized by use of only one system of function generator.

Abstract: This invention relates to a cold trap for collecting impurities from liquid, which comprises a mesh screen and a spacer mesh having higher strength and wider mesh holes than that of the mesh screen interposed between the windings of the mesh screen. According to the present invention, since the spacer mesh supports the mesh screen over the whole surface thereof so that the mesh screen is protected free from break or deformation, the stiffness and collecting efficiency of the mesh section can be maintained prolongedly.