Abstract: A high density optical data storage system employing a laser beam for reading data in a track on a rotating optical disk containing a large number of closely spaced concentric tracks. The system provides for track following as well as long and short seek track moving operations. Track following and short seeking operations share the use of a galvanometer-controlled mirror in the path of the beam, while long seek operations are performed using a positioning motor which is also used during track following to reduce the deflection required to be provided by the galvanometer mirror. The short seek operation uses a specially shaped doublet waveform comprised of opposite polarity pulses chosen based on the number of tracks to be moved and the mechanical characteristics of the system.

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 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 closely spaced concentric tracks. When a long seek operation is to be provided, track following is suspended and a linear motor drives a galvanometer-controlled mirror to a new position corresponding to a new track called for by the long seek operation. Arrival at the new position is determined by detecting when both the velocity of the linear motor and the difference between current and desired positions are below predetermined maximum values indicating that a stable condition has been reached, after which track following operation is resumed. The linear motor also operates during track following in response to the detected angular position of the mirror so as to cause movement of the mirror in a direction which reduces the mirror deflection required to maintain the beam accurately following the track.

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.