Abstract: A disk cartridge having a housing in which a disk is rotatably mounted via a hub assembly. The housing includes two cover plates, each of which has a door aperture that is selectively covered by a door that is controlled by a dedicated door control assembly. When the cartridge is inserted into a disk drive, each door is opened by its respective door opening assembly such that both sides of the disk are accessible for magnetic or optical read/write operations.In the preferred embodiment, the hub assembly includes two hub halves, at least one of which includes a plurality of resilient fingers for leveling a surface of the disk when the cartridge is contained within the disk drive. At least one of the hub halves also includes a channel having a plurality of pockets formed therein such that when a spindle base having a torque transferring element is positioned adjacent to the pockets, one of the pockets is able to substantially immediately receive the torque transferring element.

Abstract: An optical disk recording system including a record medium is disclosed for providing an accurate track crossing count and an accurate track following signal. A first embodiment utilizes off-centered wobbled areas located in the headers of the record medium. The high frequency content of a first signal is combined with the low frequency content of a second signal, which is generated using the wobbled areas. In another embodiment, light-reflective discontinuities are provided in the header areas of the record medium. A qualifier and an AGC are utilized in providing a corrected track following signal. In still another embodiment, reflective discontinuities are located in the servo areas of the record medium. In such an embodiment, it is preferred that there be a fixed gain adjustment to a radial push-pull signal.

Abstract: For magneto-optic data recording, permanent magnets are used to produce a magnetic field with a variable field strength. The field strength is varied by controlled rotation of the magnets about their longitudinal axis, which also allows inversion of the direction of the magnetic field. The magnets are oriented such that their combined fields produce a resultant force continuously substantially perpendicular to the recording medium despite rotation of the magnets.

Abstract: An optical storage disk reading apparatus (10) allows the simultaneous reading of both sides of an optical storage disk (44). An upper base plate (12) and a lower base plate (14) pivot about hinges (22-28) through the action of lead screws (30-32). The lead screws (30-32) are turned by separate stepper motors (38-39) which drive follower nuts (34-36) therealong. The follower nuts (34-36) are interconnected to the baseplates (12-14) by yokes (40-42). As the lead screws (30-32) drive the follower nuts (34-36), the yokes (40-42) pivotally move the base plates (12-14) about the hinges (22-28). A cartridge (46) containing the storage disk (44) is loaded into the apparatus (10) along receiving channels (48-50). The channels (48-50) hold the cartridge (46) from movement while the disk (44) is free to move therein with the lower base plate (14) through an interconnecting drive spindle (20).

Abstract: Method and apparatus useful in monitoring and adjusting focus and tracking of a read/write beam in a data disk-storage system are provided. In one embodiment, the reflected beam is split into a plus first order, astigmatically focused first beam and a minus first order astigmatically focused second beam. The two beams produce images which change in a mirror symmetric fashion in response to changes in the focus or tracking but in a parallel fashion in response to changes in the optical axis. Signals from detectors of the two beams are combined to negate the influence of optical axis movement or other optical faults. In another embodiment, a beam reflected from the disk is split into a first beam converging on an image plane and a second beam defocused at the image plane. The second beam has a relatively large diameter at the image plane and is relatively insensitive to optical axis deviations. Phase relationships of the second beam are used to determine if the beam impinging of the disk is focused.

Abstract: A magneto-optic data recording system and actuating device therefor comprises a permanent magnet mounted adjacent to a magneto-optic disk medium. The permanent magnet is rotatable about its longitudinal axis to change the polarity of the magnetic field which supplied to the medium. Rotation of the magnet is achieved by activation of electromagnet actuators located laterally adjacent to the permanent magnet. Rotation of the magnet through 180.degree. is preferably achieved within less than 1 period of revolution of the disk, preferably less than 1/2 the period of revolution of the disk.

Abstract: An optical disk recording system including a record medium is disclosed for providing an accurate track crossing count and an accurate track following signal. A first embodiment utilizes off-centered wobbled areas located in the headers of the record medium. The high frequency content of a first signal is combined with the low frequency content of a second signal, which is generated using the wobbled areas. In another embodiment, light-reflective discontinuities are provided in the header areas of the record medium. A qualifier and an AGC are utilized in providing a corrected track following signal. In still another embodiment, reflective discontinuities are located in the servo areas of the record medium. In such an embodiment, it is preferred that there be a fixed gain adjustment to a radial push-pull signal.

Abstract: An actuator assembly for use in an optical disk information processing system is disclosed having improved performance characteristics for achieving a large radial movement frequency bandwidth. The actuator assembly includes an actuator body defining a rail channel for movement on a single rail. The device is configured so that the center of mass of the actuator body is above the friction surfaces between the rail and the rail channel. The actuator body includes an optical channel for receiving an optical beam to be focused on an optical disk. This optical channel is positioned between two focus supports which support a lens holder which is movable for focusing the incoming optical beam onto the optical disk. The focusing motor, including a coil and focusing magnets, is positioned below the center of mass of the actuator to achieve a balanced device. The radial drive assembly for the device includes a coil directly wound on the actuator body which encircles the optical channel and the rail channel.

Abstract: An optical disk recording system including a record medium is disclosed for providing an accurate track crossing count and an accurate track following signal. A first embodiment utilizes off-centered wobbled areas located in the headers of the record medium. The high frequency content of a first signal is combined with the low frequency content of a second signal, which is generated using the wobbled areas. In another embodiment, light-reflective discontinuities are provided in the header areas of the record medium. A qualifier and an AGC are utilized in providing a corrected track following signal. In still another embodiment, reflective discontinuities are located in the servo areas of the record medium. In such an embodiment, it is preferred that there is a fixed gain adjustment to a radial push-pull signal.

Abstract: Calibration of read timing, write timing and focus is accomplished automatically by comparing reflectance signals. The timing or focus settings are preferably modified, and signals are again compared under the modified adjustment settings. The read timing adjustment includes comparing signals from mark positions immediately preceding and immediately following an isolated mark and adjusting read delay to achieve small or minimum differences between the signals at the mark positions immediately preceding and immediately following the isolated mark bit position. Focus calibration is accomplished by comparing the value of the signal from a mark with the value from a mark position immediately adjacent the mark and adjusting the focus offset until a larger maximum difference between the two signals is achieved.

Abstract: Provided is a read signal offset during write verify which prevents the false detection of amorphous pips from an optical disk recorder. Amorphous pips are the signals caused by the drop in reflection from an optical disk after the laser has caused the surface material to change from its crystalline state to an amorphous state, but not to a hole. When a hole is not formed in the material, the amorphous material later recrystallizes, the drop in reflection no longer occurs and information is lost.

Abstract: Method and apparatus useful in monitoring and adjusting focus and tracking of a read/write beam in a data disk-storage system are provided. In one embodiment, the reflected beam is split into a plus first order, astigmatically focused first beam and a minus first order astigmatically focused second beam. The two beams produce images which change in a mirror symmetric fashion in response to changes in the focus or tracking but in a parallel fashion in response to changes in the optical axis. Signals from detectors of the two beams are combined to negate the influence of optical axis movement or other optical faults. In another embodiment, a beam reflected from the disk is split into a first beam converging on an image plane and a second beam defocused at the image plane. The second beam has a relatively large diameter at the image plane and is relatively insensitive to optical axis deviations. Phase relationships of the second beams are used to determine if the beam impinging on the disk is focused.

Abstract: An optical disk recording system including a record medium is disclosed for providing an accurate track crossing count and an accurate track following signal. A first embodiment utilizes off-centered wobbled areas located in the headers of the record medium. The high frequency content of a first signal is combined with the low frequency content of a second signal, which is generated using the wobbled areas. In another embodiment, light-reflective discontinuities are provided in the header areas of the record medium. A qualifier and an AGC are utilized in providing a corrected track following signal. In still another embodiment, reflective discontinuities are located in the servo areas of the record medium. In such an embodiment, it is preferred that there be a fixed gain adjustment to a radial push-pull signal.

Abstract: An optical disk recording system including a record medium is disclosed for providing an accurate track crossing count and an accurate track following signal. A first embodiment utilizes off-centered wobbled areas located in the headers of the record medium. The high frequency content of a first signal is combined with the low frequency content of a second signal, which is generated using the wobbled areas. In another embodiment, light-reflective discontinuities are provided in the header areas of the record medium. A qualifier and an AGC are utilized in providing a corrected track following signal. In still another embodiment, reflective discontinuities are located in the servo areas of the record medium. In such an embodiment, it is preferred that there is a fixed gain adjustment to a radial push-pull signal.

Abstract: A system for generating toric optical surfaces having two different radii (or axes) of curvature with accurate centration. A multiplicity of such surfaces for use as lenses are simultaneously created. Each surface is mounted transversely to the periphery of a spinning disk of a radius equal to one of the desired arcs. Generating, lapping and polishing tools are rotated about an axis perpendicular to the disk's axis but displaced from the disk's axis by an amount equal to the difference between the radii of the desired arcs.

Abstract: An apparatus and method are provided for generating a coarse actuator drive signal. A fine actuator, operatively attached to a coarse actuator, defines an optical pathway through which light reflected from various structures residing on a disk passes. A split detector, attached to the coarse assembly and positioned to intercept light from the optical pathway, receives the light reflected by the structures residing on the disk and generates signals representative of the light incident on each half of the split detector. A difference between the signals produced by the split detector indicates that the coarse actuator is not centered or aligned with respect to the fine actuator. Processing circuitry processes the signals produced by the split detector according to the disk structure utilized to produce the signals and generates a coarse actuator drive signal.

Abstract: A track seeking method is provided which relies on sampled seek information. No external sensors are employed and the seek information is intermittently stored along the tracks provided on the disk surface. In determining the actual velocity of the seek actuator, at least two methods for counting crossed tracks are utilized. Preferably, a 1/2-count method is used at lower seek velocities and a 16-count method is used at higher seek velocities. The 178 -count method involves the receipt of two counts for each track that is crossed, while the 16-count method involves counting every sixteen tracks that are crossed. The selection of the 1/2-count and the 16-count methods for counting tracks crossed results in a velocity gap region. The velocity gap region is a range of seek actuator velocities in which the servo loop is underdamped for the 16-count method and where folding occurs for the 1/2-count method. To overcome the underdamping and folding problems, various solutions have been devised.

Abstract: A take-up assembly for operating a mechanism for loading and unloading the leader block of a tape cartridge, and for receiving the web of tape which it contains for subsequent transport, stores energy for transfer to the leader block loading/unloading mechanism when it is to operate to load or unload the leader block, so that even a conventional take-up motor is made capable of supplying the increased energy needed for leader block loading/unloading.A preferred take-up assembly includes a hub which is directly coupled to the take-up motor and which serves to receive the web of tape for direct transport, and a coupling which is nested within the hub and which receives the leader block loading/unloading mechanism. A pin depends from the coupling and into a circumferentially arranged slot formed inthe hub, to connect the hub and coupling as the pin engages the ends of the slot.

Abstract: A disk drive includes a drive mechanism for engaging the disk of a disk cartridge. A support is provided to move the drive mechanism into engagement with the disk. Several alternative supports are disclosed, employing cam mechanisms to pivotally move the drive mechanism. Also, pins are provided to restrain the cartridge housing from movement while the support is operated. An actuator is provided to open the cartridge as it is inserted into the drive.

Abstract: An apparatus for loading and unloading a tape cartridge, particularly an IBM 3480 tape cartridge, has a loading rack for receiving the tape cartridge along one of its side edges, so that what is normally considered to be the rear edge of the tape cartridge is laterally received within the loading/unloading mechanism, and equipment for properly interacting with the tape cartridge in this modified orientation for engagement of the leader block of the tape cartridge so that the tape cartridge is then ready for loading into the transport apparatus and for detection of the condition of the tape cartridge within the apparatus.