SPACE FILTER SPEEDOMETER

摘要

PURPOSE:To facilitate working with a simplified construction by making up a space filter of a laminated prism in which two types of prisms different in the direction of the normal on a refractive surface are laminated alternately in plurality. CONSTITUTION:A laminated prism forms a space filter by laminating two types of prism as shown by A and B so alternately in plurality on upon another side that the incidence surfaces thereof align by varying the direction of a refracted light. The prism A has the refractive surface 2A at an accute angle 1 with the incidence surface 1A while the prism B has the refractive surface 2B at an accute angle 2 with the incidence surface 1B. According to the invention, the use of a space filter formed by laminating prisms simple in the shape enables a highly accurate speed measurement easy to work with a simple construction free from effect of heat and noise.