Abstract: A method of fabricating a MOS transistor having a thinned channel region is described. The channel region is etched following removal of a dummy gate. The source and drain regions have relatively low resistance with the process.

Abstract: Various embodiments of the present invention are generally directed to processing servo data on a storage surface by detecting a time difference between consecutive read signal envelopes from spiral servo information on the surface.

Abstract: The present invention relates to a system for determining whether the flying height of a read/write head above a disk in a disk drive is within an acceptable range, in substantially real time. The system relies on variations in read signal resolution with flying height to make the determination. In one embodiment, read signal resolution is measured and compared to a predetermined threshold value to determine whether the present flying height is in the desired range. In another embodiment, the number of peaks in a read signal that are detected (and/or not detected) by a detector is used to determine whether the head is in the proper flying height range. Because of read signal resolution effects, the number of detected peaks will decrease as the flying height of the head is increased. Means are also provided for postponing a transfer of data to/from the disk when it is determined that the head is not within the acceptable range.

Abstract: The present invention relates to a system for determining whether the flying height of a read/write head above a disk in a disk drive is within an acceptable range, in substantially real time. The system relies on variations in read signal resolution with flying height to make the determination. In one embodiment, read signal resolution is measured and compared to a predetermined threshold value to determine whether the present flying height is in the desired range. In another embodiment, the number of peaks in a read signal that are detected (and/or not detected) by a detector is used to determine whether the head is in the proper flying height range. Because of read signal resolution effects, the number of detected peaks will decrease as the flying height of the head is increased. The system also provides for postponing a transfer of data to/from the disk when it is determined that the head is not within the acceptable range.

Abstract: The present invention relates to a system for determining whether the flying height of a read/write head above a disk in a disk drive is within an acceptable range, in substantially real time. The system relies on variations in read signal resolution with flying height to make the determination. In one embodiment, read signal resolution is measured and compared to a predetermined threshold value to determine whether the present flying height is in the desired range. In another embodiment, the number of peaks in a read signal that are detected (and/or not detected) by a detector is used to determine whether the head is in the proper flying height range. Because of read signal resolution effects, the number of detected peaks will decrease as the flying height of the head is increased. The system also provides for postponing a transfer of data to/from the disk when it is determined that the head is not within the acceptable range.

Abstract: The present invention relates to a system for determining whether the flying height of a read/write head above a disk in a disk drive is within an acceptable range, in substantially real time. The system relies on variations in read signal resolution with flying height to make the determination. In one embodiment, read signal resolution is measured and compared to a predetermined threshold value to determine whether the present flying height is in the desired range. In another embodiment, the number of peaks in a read signal that are detected (and/or not detected) by a detector is used to determine whether the head is in the proper flying height range. Because of read signal resolution effects, the number of detected peaks will decrease as the flying height of the head is increased. The system also provides for postponing a transfer of data to/from the disk when it is determined that the head is not within the acceptable range.

Abstract: The present invention relates to a system for determining whether the flying height of a read/write head above a disk in a disk drive is within an acceptable range, in substantially real time. The system relies on variations in read signal resolution with flying height to make the determination. In one embodiment, read signal resolution is measured and compared to a predetermined threshold value to determine whether the present flying height is in the desired range. In another embodiment, the number of peaks in a read signal that are detected (and/or not detected) by a detector is used to determine whether the head is in the proper flying height range. Because of read signal resolution effects, the number of detected peaks will decrease as the flying height of the head is increased. The system also provides for postponing a transfer of data to/from the disk when it is determined that the head is not within the acceptable range.

Abstract: The present invention relates to a system for determining whether the flying height of a read/write head above a disk in a disk drive is within an acceptable range, in substantially real time. The system relies on variations in read signal resolution with flying height to make the determination. In one embodiment, read signal resolution is measured and compared to a predetermined threshold value to determine whether the present flying height is in the desired range. In another embodiment, the number of peaks in a read signal that are detected (and/or not detected) by a detector is used to determine whether the head is in the proper flying height range. Because of read signal resolution effects, the number of detected peaks will decrease as the flying height of the head is increased. The system also provides for postponing a transfer of data to/from the disk when it is determined that the head is not within the acceptable range.

Abstract: Separate servo parameter values are combined into a single servo parameter value having a bit length shorter than the total bit length of the separate parameter values. The combined parameter value is then stored in a servo field on a storage disk. By storing the shorter combined parameter, a given amount of servo information can be stored in a smaller space on the disk, thereby reducing overhead. In one embodiment, servo parameters are added together to create the combined parameters. In another embodiment, an equation is provided for creating the combined parameters, that results in a relatively large numerical distance between combined parameters in adjacent servo sectors on a track of the storage disk. The combined parameters stored on the disk can be used, for example, to check the accuracy of software position estimators in the disk drive.

Abstract: A hard disk drive that contains a detection circuit which senses the back emf of a voice coil. The detection circuit generates a shock detection signal when the back emf of the voice coil exceeds a pre-determined value. The write disable gate of the disk drive is disabled when the voltage detection circuit generates the shock detection signal.

Abstract: An improved high resolution rotating head ultrasonic scanner is provided for use in an ultrasonic scanning subsystem of an ultrasonic breast scanning system. The scanning subsystem of the breast scanning system includes a pair of high resolution ultrasonic rotating scanning heads mounted on a transport mechanism. A scan is conducted by moving the transport mechanism while the scanning heads rotate so that a series of parallel uniformly spaced cross-sectional scans of the tissue of the breast are conducted from the inferior to the superior border of the breast. Each scanning head has three ultrasonic transducers uniformly spaced around its perimeter. The focal ranges of the transducers of a given scanning head are chosen so that a sector scan conducted by each head is divided into slightly overlapping zones with the depth of each zone corresponding to the focal range of one of the transducers on each scanning head.

Abstract: An improved high resolution rotating head ultrasonic scanner is provided for use in an ultrasonic scanning subsystem of an ultrasonic breast scanning system. The scanning subsystem of the breast scanning system includes a pair of high resolution ultrasonic rotating scanning heads mounted on a transport mechanism. A scan is conducted by moving the transport mechanism while the scanning heads rotate so that a series of parallel uniformly spaced cross-sectional scans of the tissue of the breast are conducted from the inferior to the superior border of the breast. Each scanning head has three ultrasonic transducers uniformly spaced around its perimeter. The focal ranges of the transducers of a given scanning head are chosen so that a sector scan conducted by each head is divided into slightly overlapping zones with the depth of each zone corresponding to the focal range of one of the transducers on each scanning head.

Abstract: Method and apparatus for optically recording and reproducing video signals. The intensity of a laser beam is modulated as a function of the amplitude of the video signals. The modulated laser beam is caused to conduct a raster scan synchronized by standard TV sync pulses and used to expose photographic film. Horizontal and vertical sync bars of contrasting optical density are recorded beyond the borders of the raster. The developed film is a directly viewable reproduction of the image scanned to produce the video signals recorded. To reproduce the video signals, an unmodulated laser beam conducts a raster scan of the developed image recorded on the film. The intensity of the scanning beam is modulated by the optical density of the film and converted to amplitude modulated electrical signals, a reproduction of the video signals recorded.

Abstract: A memory expansion apparatus is disclosed which provides for expansion of memory capacity by use of logic associated with memory modules. The logic provides for selection of one of a plurality of pages, each having substantially the same address therefor. The device provides for the selection by utilization of a special instruction, and includes decoding means for specialized bits in the instruction. Means are provided wherein repeated access to the same page in a block occurs free of a requirement of repeated address decoding amongst the plurality of pages in the block.