Abstract: An apparatus for reading/writing data from/to a magnetic disk comprises an objective lens disposed in an actuator body for focusing laser light onto the magnetic disk. A magnetic head suspension assembly includes a magnetic recording head attached to the actuator body, a suspension arm having a proximate end fixedly attached to the actuator body, a distal end with a tab, and a gimbal located between the distal and proximate ends. The magnetic recording head is attached to the gimbal. A mechanism having an extending member moveable in a first direction engages and moves the tab until the magnetic recording head is placed in an unloaded position. The extending member moves in a second direction to release the tab such that the magnetic recording head is placed in a loaded position.

Abstract: A magneto-optical (MO) disc drive including a novel suspension, slider body, airbearing surface, and magnetic head. The MO disc drive includes a fine-focus actuator block including an objective lens, wherein the coarse carriage block moves radially above a surface of an MO disc to position the objective lens. The MO disc drive also includes a flat suspension having a first end and a second end, wherein the first end is fixedly attached to the fine-focus actuator block and the second end is attached to the coarse carriage block. A gimbal is moveably attached to an opening in a surface of the suspension and a magnetic head assembly is attached to the gimbal. The magnetic head assembly is loaded and unloaded by the load/unload mechanism independent of the objective lens and attached to the coarse actuator.

Abstract: A method of using laser light to access a magneto-optical disc utilizes first and second objective lenses, the second objective lens being mounted in a light channel of a slider having a primary planar surface that flies over the surface of the magneto-optical disc. The laser light is directed through the first and second objective lenses that focus the laser light onto the surface of the magneto-optical disc. Focus of the laser light is maintained solely by moving the first objective lens in an axial direction with respect to the magneto-optical disc, the first objective lens being mounted to an actuator.

Abstract: A method and apparatus for reading from and writing to a magneto-optical disc. The apparatus comprises a first objective lens situated between a first side of the magneto-optical disc and a first source of a laser light. The apparatus further comprises a first flying magnetic head situated between the first objective lens and the first side of the magneto-optical disc, including a first coil for supplying a first magnetic field, the first coil defining a light channel through the first flying magnetic head for allowing the laser light to reach the magneto-optical disc.

Abstract: A magneto-optical disc is described. The magneto-optical disc comprises a substrate and a magneto-optical recording layer applied over the substrate. The magneto-optical disc further comprises an overcoat layer applied over the recording layer having a thickness in a range between 25 nanometers and 200 microns, wherein data is recorded on the magneto-optical disc and read from the magneto-optical disc using a laser light that is incident on the overcoat layer.

Abstract: A method and apparatus for magneto-optical storage and access of data. The apparatus comprises a flying magnetic head, wherein the flying magnetic head comprises: a slider that flies over a magneto-optical disc during read and write operations performed on a magneto-optical disc; a magnetic coil fixedly attached to the slider, the magnetic coil defining a channel through the slider, the magnetic coil and the slider forming a smooth, planar surface parallel to a surface of the disc during read and write operations; and a first objective lens fixedly attached in the channel such that a surface of the first objective lens is parallel to the smooth, planar surface.

Abstract: A magneto-optical (MO) disk drive. In one embodiment, the MO disk drive comprises a drive controller that controls operation of a laser source and a disk drive mechanism. The drive controller comprises a microprocessor and a memory subsystem coupled to the microprocessor. The memory subsystem comprises a memory device that stores programs directing operation of the disk drive and information used by the programs during operation of the disk drive. The stored information comprises an identifier that matches an identifier of a magnetic medium. The stored information also comprises a set of constant values characteristic of physical properties of the magnetic medium denoted by the letters h, k, s, c, .alpha., .beta. and .delta.. The stored information also comprises a set of equations that determine optimum write powers as a function of linear velocity, v, of the magnetic medium. The equations include:Ph(v)=hv.sup..alpha., Ph(v) is a preheat power;Pk(v)=kv.sup..beta.

Abstract: An optical recording system having a routing prism and an objective lens bonded together with a slider to form an integrated unit. A slider is attached to the end of an arm of a rotary actuator. Housed within the slider is a prism and an objective lens. The prism directs a laser beam downwards through the objective lens which focuses the laser beam onto the surface of an optical disk.

Abstract: A telecentric rotary actuary in an optical storage system. A laser generates a laser beam which is focused by an objective lens onto an optical disk in order to write data to and read data from the optical disk. In performing a seek, a galvo rotates a mirror in order to reflect the laser beam to different radial displacements in reference to the optical disk. The position of the laser beam is detected, and a rotary actuator, to which the objective lens is attached, follows the movement of the laser beam. A telecentric optical system comprising a relay lens and an image lens is used to minimize an offset between the laser beam and the objective lens. The relay lens focuses the laser beam to a back focal point. The image lens optically conjugates the back focal point to a front focal point corresponding to the objective lens in order to demagnify any offset.

Abstract: An apparatus for setting a threshold voltage for determining bit positions of digital data stored on an optical recording device utilizing pulse width modulation. The optical recording device reads a pattern from an optical medium. The read pattern has a fixed, known duty cycle. A feedback circuit processes the pattern according to an initial threshold voltage. The feedback signal is then input to a comparator. The comparator compares the feedback signal against the pattern. Based on this comparison, the amount of current input to and output from a compensation circuit is adjusted. Thereupon, the compensation circuit sets the threshold voltage accordingly.

Abstract: An optical recording system having a DC restored read signal for qualifying pulses in the read channel. The equalized and filtered read signal is input to a differentiator and a DC restore circuit. The zero crossings of the differentiated signal which represent the peaks of the pulses are detected. The DC restore circuit inverts the read signal, generates a reference voltage, and compares the negative pulses peaks of the read signal to the reference voltage. The charge of a capacitor is adjusted according to the difference in voltages of the pulse peaks to that of the reference voltage in order to maintain a constant DC level. The DC restored signal is qualified according to a threshold. Only those pulses which have zero crossings and which have been qualified are considered to be valid.

Abstract: In an optical recording system employing a laser for writing digital data onto a storage medium, an apparatus and method for calibrating a laser to a power level which minimizes write errors. A calibration profile is generated by writing test data patterns onto the storage medium by using a number of different predetermined laser power levels. The test data patterns are then read back. The number of write errors is determined for each of the different laser power levels by comparing the written data patterns to the read back data patterns. The calibration profile denotes the number of write errors as a function of laser power levels. Next, an optimum laser power is determined corresponding to an average of an upper and a lower knee of the calibration profile. The laser is calibrated to this optimum power level.

Abstract: An optical recording system having a laser for generating a light beam to write data to and read data from a storage medium, an RF modulator for modulating the laser to improve its stability, and an apparatus for driving the laser. The apparatus is comprised of a transistor coupled to the laser for supplying current to the laser. An amplifier is implemented to drive the base of the transistor according to a microprocessor. Thereby, the microprocessor effectively controls the power level of the laser. The transistor and the RF modulator are enclosed within shielding to contain the RF energy being generated by the modulator. In addition, the collector-base separation of the transistor reduces the RF energy being transmitted through the line driving the base of the transistor.

Abstract: An apparatus and method for cleaning components internal to an optical recording system without requiring the optical recording system to be disassembled. The apparatus is comprised of inlets through which pressurized gas is fed. The pressurized gas is directed through channels within the apparatus to various outlets. The pressurized gas is then expelled from these outlets. When the apparatus is inserted in the optical recording system, the outlets are located next to components sensitive to particle contamination. Thus, the expelled gas removes the particle contaminants from the surfaces of the components, thereby enhancing operation of the optical recording system.

Abstract: In an optical disk drive system, an apparatus and method for determining whether data read from a particular field within a particular sector of an optical disk corresponds to a code which specifies that the sector should not be erased. A crystal clock generates a synthesized clock signal. A front-end detector generates a signal synchronized to the synthesized clock signal which represents data read from the field. The signal is then serially shifted by a serial shift register. A comparator compares the shifted signal with the code specifying that the sector should not be erased. If there is a match, a counter is incremented. When the counter reaches or exceeds a pre-determined number, a signal is sent to the optical disk drive system indicating that the sector contains data which should not be erased.

Abstract: A track seek method for a disk drive system. In the seek method of the present invention, the head is moved according to the characteristics of an ideal, electronically generated signal which is independent from data read off the disk. By varying the characteristics of the ideal signal, the seek profile is controlled. The ideal signal is sampled at times specified by an error signal which is based upon data read off the disk. The movement of the head is adjusted according to the sampled signal. Since track crossings correspond to ideal signal cycles, the number of tracks crossed is determined by counting the number of cycles of the ideal signal. Consequently, the position of the head is known at all times throughout the seek, thereby maintaining the seek in a closed-loop configuration during the entire seek. When the appropriate number of tracks have been counted, the head is stopped on the destination track and the head can access data contained therein.

Abstract: A seek method for disk drive is described. In the seek method of the present invention, the tracking servo loop remains in a track positioning mode throughout the entire seek process. By effectively varying the reference position of the head with respect to track center under a predetermined profile, the track positioning mode is utilized to produce a pseudo-continous movement across the disk surface. In essence, the servo track following loop attempts to mainta position relative to a local track center as dictated by profile information supplied by a microprocessor. The system of the present invention is an open loop in the sense that no attempt is made to loop information about deviation from the predefined profile back to the microprocessor. Local positioning, however, remains closed loop at all times so that the system is always within the predicted track and arrives directly on target.