LIGHT SOURCE TRACKING DEVICE

PURPOSE:To provide a light source tracking device for use in a spatial optical communication between a sending station (e.g. a portable transmitter) and a receiving station (e.g. an airborne receiver) which move relative to each other. CONSTITUTION:A plurality of light-receiving sensors 8a-8d each of which reacts to an optical signal 12 of a limited angle of visibility are distributed over a plane orthogonally intersecting an axis 3 of rotation. Each of the light-receiving sensors 8a-8d is oriented toward either right or left partial space defined by division of a circumference on the plane by means of a collimation axis 13 and is installed while being so arranged to cover the whole area. A circuit which decides to which of the right and left partial spaces the optical signal 12 belongs when either of the light-receiving sensors 8a-8d detects the oncoming optical signal 12, and an automatic control system which according to the decision of the circuit rotates the collimation axis 13 toward the partial space to which the optical signal belongs are installed and the position of a light source (optical signal) is tracked in all directions. It is thus made possible to automatically track the optical signal 12 (light source) in all directions using a very simple mechanism, helping realize an optical communication between stations moving relative to each other.