Abstract: A laser optical system including a reading beam for reading optical data recorded in one or more tracks of a rotating disk optical recording medium. The disk includes a plurality of preformatted headers spaced along the track wherein each header includes first and second track following optical holes which are elongated in the direction of the track and disposed on opposite sides of the track center line in a staggered relationship along the track. Traversal of these track following holes by the reading beam produces a reflected beam which varies in a manner dependent upon the accuracy of positioning of the beam relative to the track center line. Up-down integration circuitry responsive to this reflected beam is used to produce a track following signal which is applied to a radial position control motor for maintaining the beam precisely on the track center line.

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 laser optical system including a reading beam for reading optical data recorded in one or more tracks of a rotating disk optical recording medium. The disk includes a plurality of preformatted headers spaced along the track wherein each header includes a plurality of spaced focusing optical holes having dimensions chosen based on the diameter of the focused laser beam spot. Traversal of these optical holes by the reading beam produces a reflected beam which varies in a manner dependent upon the quality of focusing of the beam. Peak detection circuitry responsive to this reflected beam is used to produce a high gain focusing signal which is combined with a low gain, high capture range focusing signal provided by a geometric focus detector to derive a precise, offset-free focusing control signal which is applied to a focusing motor to main precise focusing of the beam on the disk.

Abstract: A preformatted optical recording disk for use in an optical data storage system in which a laser beam of predetermined frequency is focused on the disk. The disk comprises a substrate having reflective, dielectric and absorbing layers deposited in a manner so as to establish an anti-reflection condition for an incident laser beam. The disk is preformatted by recording optical holes in the absorbing layer so as to form one or more tracks wherein each track includes a plurality of headers positioned at predetermined locations along the track. Each header comprises a plurality of optical holes constructed and arranged so as to constitute predetermined embedded timing, track following and focusing data on the disk for use by an optical data storage system.