Abstract: A high density optical storage system employing a laser beam for reading data in a track on a rotating optical disk containing a large number of concentric tracks. Track following is provided using a galvanometer-controlled mirror in the path of the beam which is angularly deflected during track following in response to detected track deviations, whereby the beam is controlled to accurately follow the track. Provision is also made for detecting the angular position of the mirror. A linear motor responsive to the detected angular position moves the mirror in a direction which reduces the deflection required to be provided by the mirror in order to maintain the beam accurately following the track. The mirror is also controlled in response to the rate of change of the linear motor velocity for providing greater system stability.

Abstract: A number of planar diplexers which intersect a beam radiated from a primary projector at respectively predetermined angles, which are separated from the projector and from each other, are provided with respectively predetermined conductor patterns. The diplexers are arranged successively in a frame together with the primary projector, whereby various radiation patterns can be formed by different combinations of a number of beams which are reflected respectively by the planar diplexers at respectively predetermined rates. As a result, a power distribution type antenna having a small and simple structure adapted for multipurpose and multifunction applications, particularly for installation on a communication satellite, based on the portability and the ease of assembling thereof, can be realized.