Storage Technology Corporation Partners Ii

Storage Technology Partners 11

Stuff Technology Partners-ii

Dazar Corporation

James W Baer

Scott David Wilson

Paul M Romano

Charles M Reilly

James W Hargarten

Richard B MacAnally

Robert P McIntosh

Brad R Reddersen

Scott L DeVore

Majed K Abed

Henry H Hoshiko

The carriage optics system for an optical data storage system includes a read/write head that consists of fixed and moving optics. The moving optics includes a carriage actuator that is equipped with a beam relaying telescope lens system that minimizes the defocusing effects of the movement of the carriage actuator.

Carriage optics system for optical data storage system

An improved coarse access and tracking servo system for use with an optical disk storage system is disclosed. Concentric servo tracks placed on the disk are readily distinguished from data tracks placed on the disk which may or may not be present on the disk depending upon the amount of information that has been written on the disk, i.e., how 'full' the disk is with respect to its maximum capacity for storing data. A predetermined signal is embedded within each of the plurality of concentric servo tracks found on the disk. A radial strip or line, sufficiently long to always include at least one servo track, but also long enough to include data tracks, if any, on either side of the illuminated servo track is projected on the surface of the disk in order to detect the servo tracks. Light returned from the illuminated servo tracks falls upon a detector and generates a frequency component that is readily distinguished from any frequency components associated with signals generated from light returned from any of the data tracks. The position of the servo track within the illuminated radial strip or line is then accurately determined, regardless of whether data tracks are present or not within the illuminated strip or line. This position of the servo track within the illuminated radial strip or line is then used by the coarse access and tracking servo system in order to accurately position an optical head at a desired position with respect to a selected coarse servo track on the disk.

Optical disk for detesting and distinguishing servo tracks from data

An optical system for writing and reading data from a rotating optical storage disk, comprising a first, second and third coherent light source, providing coarse seek, reading, and writing functions, the three writing sources sharing a plurality of optical elements in common, all cooperating to provide for the coarse seek, fine seek, focus and tracking functions of the device. The read and the write optical beams are optically coupled together to ensure proper spacing of a newly written track with regard to the previously written track.

Optical disk recording and readout system having read, write and coarse

A self contained, replaceable diode laser module for providing a fully collimated, de-astigmatized, and circular cross-sectioned beam. In the preferred embodiment a first compound spherical lens partially collimates the beam. An in-line combined cross-section modifier system then de-astigmatizes and modifies the cross-section of the beam. The beam modifier system is comprised of first and second triangular prisms oriented at non-normal angles to the path of the beam. This allows both the cross-section and the astigmatism of the beam to be corrected. A planar mirror between the first and second prisms directs the beam from the first prism to the second prism, so that the beam can exit the second prism co-axial with the incident beam path. The beam then enters the second collimating subsystem. This subsystem is a telescopic lens system comprised of a second and a third spherical, which simultaneously, completely collimates the beam, and expands the beam to the proper diameter for transmission through the optical system of the main device. The beam, upon existing the second collimating subsystem is a fully collimated beam, which is de-astigmatized and has a circular cross-section of the proper diameter.

An optical head structure, movable to scan over a disk surface, includes a fixed optical arrangement. Fine focussing and side-to-side adjustments for scanning are effected by movements of another lens mounted on a substantially stationary part of the system structure. The movable lens is generally aligned with the axis of the fixed lens on the movable head structure. In an alternative embodiment, lateral adjustments of scanning spot position are made by pivoting a reflecting mirror on the stationary structure and axial adjustments of the scanning spot are made by axially moving a lens on the fixed structure. Light paths in the movable head structure are altered by reflecting mirrors, all such mirrors being in fixed relationship with the fixed objective lens. The movable head structure bearing fixed lenses and fixed mirrors mvoes in an arc, not concentric with disk rotation, to traverse the disk and locate a desired track.

Optical system for fast access optical data storage device

A subaperture optical system for preventing interference between light inadvertently reflected from the protective overcoat of an optical recording disk from disruptively interfering with light reflected from the active layer of the optical recording disk, thereby causing coarse servo tracking errors as the coarse servo actuator carriage translates over the coarse servo tracks on the disk service. The optical system is comprised of a laser light source, a collimating lens system, an astigmatizing lens system, a subaperture mirror, a carriage actuator, a beam relaying telescope, an objective lens, an objective lens focus actuator, a reflected coarse servo beam focusing lens, and a coarse servo detector. The laser issues a beam which follows a first subaperture path that is parallel to, but off center from, the optical axis of an objective lens of the optical system. The beam is formed into a line focused spot which is focused on the disk surface at a non normal angle. The beam reflected by the active layer and the protective overcoat are spatially separated, and therefore do not interfere. The reflected beams follow a second subaperture path to the coarse servo detector, where the reflected signal is detected unaffected by any interference between the reflected beams.

Subaperture coarse tracking optical system for optical data storage

A beam alignment system and method for aligning a first radiation beam with respect to a second radiation beam as these beams share a desired optical path. Beam steering means, such as a galvonometer controlled mirror, steer the alignment of the first beam as it enters the shared optical path. Detection means are employed to sense the relative alignment between the first and second beams as they travel through the shared path. This sensed alignment is compared to a desired alignment, and a position error signal is generated to indicate the error therebetween. The position error signal, in turn, is used to steer the galvonometer controlled mirror in order to force the beam alignment error between the two beams to zero. In a preferred embodiment, the beam alignment system is used in an optical disk storage system to precisely position a write beam a desired distance from a read beam; thereby allowing a data track written with the write beam on a storage disk to be spaced a desired distance (the track pitch) from a previously written track that is being followed by the read beam.

Beam alignment system

A beam alignment signal processing system wherein a true beam position error signal is generated regardless of beam intensity. This beam position error signal is used within a beam alignment system that maintains a desired alignment between first and second beams traveling in parallel along a desired optical path. A detector senses the position of the beams as the beams (or portions of the beams) are directed onto a surface thereof. The detector generates a set of position signals that indicate the position at which a beam, or at which an energy centroid associated with a plurality of beams, falls upon the detector surface. A first set of position signals is generated corresponding to the position of the first beam on the detector surface with the second beam turned off. These signals are stored in signal storage means. The second beam is turned back on, and a second set of position signals is generated corresponding to the position of the centroid of the first and second beams on the detector surface. A third set of position signals is then generated from the first and second set of position signals corresponding to the position of the second beam on the detector surface. The position error signal is finally generated from the first and third sets of position signals. Detector offset correction means are employed to remove the effects of detector offset from the sets of position signals. Normalization means are likewise employed to remove the effects of beam intensity variations from the sets of position signals.

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Boulder, CO, United States of America

James W Baer