Abstract: An original image or other data sequence is modified with an internal marker value, and is communicated (stored and/or transmitted) as one component of a transform having multiple complementary components. The image is restored in a closed form, without iteration, and in some cases without any loss of precision from the original image. The original image may have complex element values. Multiple original images may be combined, and separated after restoration. Several types of maps may be embedded in or packaged with the communicated component. Communicated component elements may be stored with variable lengths.

Abstract: A hybrid energy system heats or cools a plant with a geothermal unit powered at least partly by a fuel cell, which may also power other devices. The thermal fluid for the geothermal unit also cools the fuel cell via a heat exchanger. A digital controller bypasses a variable portion of the thermal fluid around the heat exchanger to regulate the fuel-cell temperature.

Abstract: An image in a base domain (e.g., spatial) is restored from only one component (e.g., magnitude) of a transform-domain (e.g., Fourier) image by combining this component with a complementary component (e.g., phase) of a transformed previous iteration. Every iteration is converted to the base domain, and predefined known marker and padding data is reapplied to the iteration during every iteration, for convergence purposes. The restored image can be scaled and trimmed, and the marker position interpolated. The original image to be restored is modified to contain the known marker and known padding at known locations. These may be inserted in the base domain or in the transform domain.

Abstract: An original image or other data sequence is modified with an internal marker value, and is communicated (stored and/or transmitted) as one component of a transform having multiple complementary components. The image is restored in a closed form, without iteration, and in some cases without any loss of precision from the original image. The original image may have complex element values. Multiple original images may be combined, and separated after restoration. Several types of maps may be embedded in or packaged with the communicated component. Communicated component elements may be stored with variable lengths.

Abstract: An image in a base domain (e.g., spatial) is restored from only one component (e.g., magnitude) of a transform-domain (e.g., Fourier) image by combining this component with a complementary component (e.g., phase) of a transformed previous iteration. Every iteration is converted to the base domain, and predefined known marker and padding data is reapplied to the iteration during every iteration, for convergence purposes. The restored image can be scaled and trimmed, and the marker position interpolated. The original image to be restored is modified to contain the known marker and known padding at known locations. These may be inserted in the base domain or in the transform domain.

Abstract: A system and method for editing program material provide viewers with real-time editing control. Digital program material are divided into relatively short segments and each of these segments are rated to indicate a level of potentially objectionable material contained therein. Each segment is tagged to indicate this rating. Prior to viewing the program material, or during playback of the program material, the viewer determines the rating level at which he or she wishes to view the program material. This rating level is entered into the playback system. Upon playback, the system examines the tag of each segment to determine whether that segment should be played. If a segment is tagged to indicate a rating with a higher level than that requested by the viewer, the tag is edited and not displayed. Thus, the program material is edited in real time as it is displayed to the viewer.

Abstract: The present invention overcomes the problems that accompany the use of ramps to load and unload transducer carrying sliders in rigid magnetic disk data storage devices. The tracks in the region where the slider loads and unloads are read and the errors recorded following each slider loading operation. One technique is to track the error increase and identify imminent device failure when the rate of error increase during a given number of the most recent slider load cycles exceeds a threshold value. In another mode, a dedicated sequence of tracks is recorded at an increased linear density to assure that read errors occur to enable a more effective comparative evaluation. This makes possible a two stage evaluation, a first threshold number of errors indicative of degrading performance which initiates lower actuator velocity to inhibit further degradation and a second threshold error quantity that indicates imminent catastrophic failure and triggers a warning to the system user.

Abstract: A disk drive stores multimedia data in long spiral data tracks. The tracks on opposite surfaces of the disk spiral in opposite directions, so that a track on one surface can be read as the actuator sweeps in, and a track on the opposite surface can be read as the actuator sweeps out. Because the actuator only follows spiral tracks without performing long seek operations, the actuator motor can be reduced in size and stresses on actuator bearings and other parts are reduced. Additionally, due to reduced disturbances associated with seeks, it is possible to follow tracks more closely and therefore reduce the width of individual tracks. Further cost reductions are accomplished by spinning the disks at a slower speed and reducing the size of the spin motor accordingly. Finally, data density can be increased simply because multimedia data does not require the same low error rate as conventional data. Preferably, a group of disk drives optimized for multimedia data is used to form a video-on-demand system.

Abstract: A method and apparatus are provided for servo demodulation in a direct access storage device. A readback signal is sensed from at least one disk surface and locations of positive and negative peaks in the sensed readback signal are detected for providing a detected peak signal. A square wave signal having a period variable with distance between detected locations of positive and negative peaks is generated using the detected peak signal and applied to a servo demodulator in the direct access storage device.

Abstract: A disk drive stores multimedia data in long spiral data tracks. The tracks on opposite surfaces of the disk spiral in opposite directions, so that a track on one surface can be read as the actuator sweeps in, and a track on the opposite surface can be read as the actuator sweeps out. Because the actuator only follows spiral tracks without performing long seek operations, the actuator motor can be reduced in size and stresses on actuator bearings and other parts are reduced. Additionally, due to reduced disturbances associated with seeks, it is possible to follow tracks more closely and therefore reduce the width of individual tracks. Further cost reductions are accomplished by spinning the disks at a slower speed and reducing the size of the spin motor accordingly. Finally, data density can be increased simply because multimedia data does not require the same low error rate as conventional data. Preferably, a group of disk drives optimized for multimedia data is used to form a video-on-demand system.

Abstract: A disk drive stores multimedia data in long spiral data tracks. The tracks on opposite surfaces of the disk spiral in opposite directions, so that a track on one surface can be read as the actuator sweeps in, and a track on the opposite surface can be read as the actuator sweeps out. Because the actuator only follows spiral tracks without performing long seek operations, the actuator motor can be reduced in size and stresses on actuator bearings and other parts are reduced. Additionally, due to reduced disturbances associated with seeks, it is possible to follow tracks more closely and therefore reduce the width of individual tracks. Further cost reductions are accomplished by spinning the disks at a slower speed and reducing the size of the spin motor accordingly. Finally, data density can be increased simply because multimedia data does not require the same low error rate as conventional data. Preferably, a group of disk drives optimized for multimedia data is used to form a video-on-demand system.

Abstract: A load/unload device to remove the slider from the proximity of the magnetic recording surface of a disk in a disk drive whenever the disk is to be stopped. The load/unload device is a ramp-like wedge which extends generally radially from the center of the magnetic disk and to the magnetic recording surface of the magnetic disk. When the slider is moved toward the center of the disk by an actuator mechanism, the end of the load arm supporting the slider, referred to as a tang, will engage the inclined plane of the wedge and lift the slider from the surface of the magnetic disk as the slider is translated closer to the center of the disk. Once the slider has been removed from close proximity of the disk, the tang may engage a trough-like surface on the structure supporting the wedge and will effectively detent the position of the slider through the forces exerted on the tang by the load beam of the actuator.

Abstract: A secondary actuator for increased positional resolution of a read/write head for a DASD is disposed on the distal end of an actuator arm and acts to pivotally move the load beam about the attachment axis. The actuator is comprised of a ring structure on the end of the load beam with the ring structure attached to a central hub through a plurality of spokes. The central hub is fixedly attached to the distal end of the actuator arm for the DASD. Relative motion between the actuator arm and the load beam is accomplished by causing a deflection in one or more of the spokes. The deflection may be caused by piezo-electric transducer elements which are attached to the sides of at least two spokes. Signals sent to the piezo-electric transducer elements will cause bending of the piezoelectric transducer elements and the attached spoke and thus rotationally displace the junction of the spoke and the ring about the central hub.

Abstract: Disclosed is a mass storage system for a data processing system providing data redundancy by mirroring files and arranging redundant record copies in a way to reduce access time and energy consumption over a pure mirrored system. A plurality of mirrored disk drives for long term storage of duplicate copies of the records are utilized. The logical address for each record is equated to relatively displaced radial locations among the mirrored disk drives. A controller for the mirrored disk drives maintains a record of correspondence between track physical addresses and logical addresses, and the current location for the transducer positioning arm for each disk drive. Upon a read access to a record, the arm closest, in terms of track displacement, from the track where a record copy is kept is used to access the record copy. Application of the method to zone bit recording system is also discussed.

Abstract: Disclosed is a disk drive having at least one disk for storing data. The disk drive includes at least one transducer for reading or writing data to or from the disk. The transducer is attached to an actuator which positions the transducer with respect to the disk. The actuator includes a controllable motor which is used to move the actuator and the transducer attached thereto. The disk drive also includes a ramp for off loading the transducer or for parking the transducer off of the surface of the disk. Also disclosed is apparatus and methods for measuring and controlling the movement of the actuator and attached transducer while the transducer is coming from a position off of the ramp and onto the surface of the disk.

Abstract: A magnetic disk drive includes redundant data written at a plurality of out of phase angular locations to reduce the latency and enhance performance during a read operation. The loss of recording capacity is reduced by increasing the data density to achieve the same soft error rate standard required for single recording. Dual recording also allows different recording codes to be used at the duplicated locations to thereby have the more highly stressed code words occur at different locations in the data to further reduce the possibility of an error. The redundant recording can be used in one portion of the media and normal recording used in another media portion to enable selection of the recording technique in accordance with the type of data being stored. The size of the normal and redundant recording portions can be controlled by the format operation and the user of the disk drive can intervene to designate the size of the redundant and normal media recording portions effected during the format operation.

Abstract: The invention produces and maintains clearance and glide test results for a disk file, stores these results, and monitors head clearance and disk asperities over the useful life of the file using native disk file electronics. The disk file includes a predictive failure analysis component which utilizes clearance and glide test results to predict impending failure of a disk in the disk file.

Abstract: A secondary data storage system for a host computer system includes a disk drive system having a device controller, at least a first magnetic disk and a read/write magnetic transducer positionable with respect to a recording surface of each magnetic disk. A write operation exposes data on adjacent tracks to potential damage if an off track condition occurs to the transducer during a write. A method for controlling write operations through the device controller provides backup of data in tracks adjacent to a target track for the write operation prior to the write operation occurring. The method detects occurrence of events resulting in an off track condition of the magnetic transducer relative to a target track. Occurrence of such an event triggers a determination of damage to the contents of tracks adjacent to the target track and restoration of those tracks. Write operations to the target track are blocked until shock events discontinue.

Abstract: A direct access storage device and a method of operation thereof where the output of the circuit which controls energy to the position actuator for the head may be changed at times between receipt of sequential position error signals from the medium. Instead of waiting for the next position error signal, a computation is done based on at least the current position and the desired position of the head as to when the head velocity will be equal to a desired velocity. The optimum time to switch is estimated, the energy required to achieve a predetermined velocity and a predetermined offset with respect to the desired position are computed, and operation is conducted accordingly. The amount of energy may again be changed at a time subsequent to the estimated time. The predetermined velocity and the predetermined offset may be zero or may have values other than zero in accordance with the requirements of the track following controller.

Abstract: Amplitude information is derived from a periodic waveform by digitally sampling the periodic waveform, filtering a digital harmonic signal out of the digital sample sequence of the periodic waveform, and computing the root mean square of the digital Mth harmonic signal over a predetermined number of successive samplings of the periodic waveform. The digital sampling is done at a rate such that there will be an integer number of samples "L" over the period of the first harmonic component of the digital sample sequence of the waveform signal. The root mean square value computation is simplified by selecting the sampling window width N and the harmonic M so that there is a predetermined relationship to a critical sampling number L given by the expression, L=(4MN)/(2j+1) where j=0, 1, 2, . . . . As long as this relationship is satisfied, the RMS value can be computed by summing the absolute value of selected digital amplitude values of the selected harmonic component of the digitized signal.