DISTANCE MEASURING GAUGE USING RELATIVE MOVEMENT BETWEEN DIFFRACTION GRATINGS

摘要

A hand held digital read-out measuring instrument in which interference fringes are generated by the transmission of radiations through gratings which move relative to one another according to a distance being measured and the fringes are counted to detect changes in the fringe pattern and generate a pulse output related to the distance, means being provided to control the rate of movement and to exert a substantially constant force on the movable elements.