Abstract: A three-dimensional measurement device employs a slit ray projection technique to optically determine a three-dimensional image. The device offers a choice in operating modes between high-speed measurement, high-resolution measurement and large dynamic range in the depth direction, to accommodate various situations. The different modes of operation are achieved by selectively modifying one or more of the scanning speed of a projected reference beam, the readout speed of a photosensor, the line width or line spacing of the photosensor, and the number of lines per image frame.

Abstract: A device for maintaining a vacuum in a compartment of a rotating member includes a collector which is mounted over an orifice of the rotating member. The collector has an end wall with an annular aperture extending axially of the rotating member. The aperture is selectively sealed by an annular valve member which permits communication of the compartment with a high-vacuum pump. The valve member may be of a magnetizable material and may be moved axially by a fixed control coil. Sealing members are provided for sealing the compartment of the rotating member with respect to a fixed member when the compartment is in communication with the vacuum pump.