摘要:
The disclosed device is directed towards an optical data storage system. The optical data storage system comprises an optical medium including a servo plane and at least one data plane. A first laser is positioned to generate a servo laser beam and address the servo plane with a first servo focus spot. A second laser is positioned to generate a read-write laser beam and address the data plane with a second read-write focus spot. A first servo system is associated with the first laser and is configured to provide focus and tracking error correction according to servo information associated with the servo plane. A second servo system is associated with the second laser and is configured to provide focus and tracking error correction according to servo information associated with the data plane.
摘要:
An optical information storage system using optical storage media including multiple data layers or stacks wherein each of the multiple data stacks has a storage density comparable to a conventional single layer optical disk. The optical data storage system comprises an optical medium having a single dedicated servo layer and multiple data stacks which each contain an embedded servo format, a servo laser beam positioned to maintain a first focus point on the dedicated servo reference layer, a read-write laser beam positioned to maintain a second focus point on one of the data stacks, a first, dedicated servo system which provides focus and tracking error correction according to error signals generated from the dedicated servo layer, and a second, embedded servo system which provides focus and tracking error correction according to error signals generated from the data stacks. The dedicated servo layer, in different embodiments of the invention, may be positioned either below or above the data stacks in the optical medium, or interposed between data stacks. The data stacks may comprise discrete physical data layers or “virtual” data layers defined by a format hologram. The servo and read-write lasers may differ in wavelength and/or polarization.
摘要:
A system for positioning a transducing head in a disc drive device over a selected track of a rotatable disc includes an actuator arm which is rotatable about an axis, a head suspension mechanism connected to the actuator arm, and a slider carrying a transducing head and supported by the head suspension mechanism. A low resolution motor moves the actuator arm about the axis to effect coarse movement of the head between tracks of the disc. A piezoelectric element is embedded in the actuator arm to distort the arm to effect fine positioning of the head. Control circuitry distributes electrical signals to the low resolution motor and the piezoelectric element to selectively control movement thereof. The piezoelectric element is embedded in the actuator arm by removing a predetermined amount of material from the actuator arm and bonding the piezoelectric element in the resulting space it the actuator arm.
摘要:
The overall response of a television receiver is displayed on the face of the cathode ray tube of the receiver involved by test apparatus which requires electrical connection only to the antenna terminals of the television receiver and the mounting of a small light sensor unit onto the face of the cathode ray tube. The test apparatus generates an amplitude modulated signal having a video carrier frequency corresponding to that of a selected television channel. The amplitude modulated video carrier frequency signal includes an envelope containing synchronizing pulses for operating the sweep circuits of the television receiver in a normal manner and which clamps the automatic gain control circuits of the receiver to a desired level and a video signal to produce a given brightness reference background on the tube face which is preferably gray or black. Periodically, the main video carrier is interrupted for the generation of a constant amplitude test carrier frequency signal. This test carrier frequency signal progressively varies in frequency during successive fields, so the test carrier frequencies will scan through the entire band of frequencies for the channel involved. The points in time at which the main video carrier is periodically interrupted is controlled so that the beam trace or traces produce a rectangle of light resulting from the video signal detected from the test carrier frequency. This rectangle of light appears opposite the light sensor unit. The brightness of the rectangle of light during each field is a measure of the overall response of the radio frequency and intermediate frequency tuned circuits in the receiver at the test carrier frequency involved. The light sensor output from each field is stored and then utilized to modulate the video carrier to produce a response curve on a curve display area of the cathode ray tube.
摘要:
A system for positioning a transducing head in a disc drive device over a selected track of a rotatable disc includes an actuator arm which is rotatable about an axis, a head suspension mechanism connected to the actuator arm, and a slider carrying a transducing head and supported by the head suspension mechanism. A low resolution motor moves the actuator arm about the axis to effect coarse movement of the head between tracks of the disc. A piezoelectric element is embedded in the actuator arm to distort the arm to effect fine positioning of the head. Control circuitry distributes electrical signals to the low resolution motor and the piezoelectric element to selectively control movement thereof. The piezoelectric element is embedded in the actuator arm by removing a predetermined amount of material from the actuator arm and bonding the piezoelectric element in the resulting space in the actuator arm.
摘要:
Junction overheating in an actuator controller IC used to position read/write heads in a magnetic disc storage device is prevented by temporarily decreasing actuator controller IC output signal duty cycle when excessive junction temperature is present. The present invention includes means for monitoring and comparing actuator controller IC junction temperature to a reference temperature, and for outputting a warning signal when junction temperature exceeds the reference temperature by too large a margin. The present invention introduces a time delay into the output signal from the actuator controller IC when the warning signal is present. The time delay may be fixed or variable in duration, and may be varied progressively in duration. The time delay may be generated using circuitry, software, firmware, or a combination thereof.
摘要:
An adaptive velocity profile system is provided for variably controlling a disk drive head in a computer disk drive or the like, to obtain substantially minimum seek times in accordance with variable operating conditions. The system monitors actual performance of the head in the course of a seek step during which the head is displaced relative to a memory storage disk for alignment with a selected track on the disk, and wherein the head performance is variable in response to a range of parameters such as temperature, power supply voltage, mechanical stiffness, etc. The monitored head performance as represented, for example, by head acceleration at the initiation of a seek step and/or by a track address mismatch at the conclusion of a seek step is used, in the preferred form, to select an appropriate one of several available velocity profiles for controlled head deceleration at the conclusion of a subsequent seek step. The selected velocity profile is chosen for obtaining the fastest possible seek times consistent with current operating conditions.
摘要:
A method and apparatus determining head position of a data transducer head relative to a selected one track of a multiplicity of concentric tracks within a magnetic/disc drive is provided. At least one prerecorded servo sector within a data track includes four time staggered servo bursts. The first pair and second pair of servo bursts are radially offset from each other by generally a burst width such that an edge from each of the pair are substantially co-linear in forming a track null. The first pair is radially offset from the second pair by one-half of the burst width. The first pair is read to determine a first relative amplitude therebetween, and the second pair is read to determine a second relative amplitude therebetween. Additionally, the radially offset and time staggered servo bursts prerecorded on the servo sector can be of varying width and numbered to create the plurality of track nulls within a data track about which the head can be positioned.