Abstract: Embodiments of the present invention provide a portable rotary disk type storage device provided with a form factor allowing dimensions of an accommodation space in a longitudinal and a lateral direction to be reduced. In one embodiment, the storage device has a head disk assembly provided with a rotary disk recording medium and a casing accommodating the rotary disk recording medium and forming a totally closed space. The device further has a PCB provided with a connection pad disposed substantially parallel with a recording surface of the rotary disk recording medium and connectable to a host system connector and a control circuit for the head disk assembly and connected to the head disk assembly with an FCP and mechanically released therefrom. Housings accommodating the head disk assembly and the PCB and having an opening portion in alignment with the connection pad are provided.

Abstract: The data possessed by a parent hard disk drive is exported to a baby hard disk drive, which is connected to the parent hard disk drive, and thus, the baby hard disk drive executes by itself an optimization/inspection process including writing of servo information. A hard disk drive is reproduced by incorporating “DNA” used for reproduction into each hard disk drive, and then, by performing self-optimization and/or self-inspection by a new hard disk drive (baby hard disk drive), according to information supplied by a finished hard disk drive (parent hard disk drive).

Abstract: A servo system wherein a read head R detects a servo pattern that is written on a magnetic disk by a write head W. Position control of the write head W is exercised in accordance with the detected servo pattern, and the read head R detects a propagation pattern that is written on the magnetic disk by the write head W. Position of the write head W is corrected in accordance with the detected propagation pattern.

Abstract: The present invention solves a problem that useless or wasted space exists on a data recording disk between read/write heads of narrower head width than others in the case that an uniform track pitch is used, and a head width of each head varies due to a fabrication tolerance. A data recording disk of the present invention comprises a first data recording surface and a second data recording surface, and a track pitch of adjacent data recording tracks of the first data recording surface differs from a track pitch of adjacent data recording tracks of the second data recording surface. All data recording tracks of the first data recording surface have substantially the same track width, and all gaps of the first data recording surface have substantially the same gap width, and, all data recording tracks of the second data recording surface have substantially the same track width, and all gaps of the second data recording surface have substantially the same gap width.

Abstract: A grinding machine includes a main spindle on which a grinding wheel is mounted, a spindle head movable relative to a workpiece, a dressing device body provided to be movable relative to the spindle head and a dresser supporting member provided to be movable relative to the dressing device body for rotatably supporting a dresser. The dressing device body is moved to a dressing position while the grinding machine grinds with continuous dressing. The dressing device body is moved to a retracted position while the grinding machine normally grinds except for the grinding with continuous dressing.

Abstract: A method and apparatus for accurately positioning the magnetic head of disk drives is disclosed. A recording medium is provided having two radial data structures formed thereon. Each radial data structure includes two parallel and adjacent data burst pattern trains. The first burst pattern is defined by a first side centrally aligned with a concentric data track and a second side opposed to the first side and centrally aligned with an adjacent concentric data track. The third burst pattern is defined by a third side spaced apart from the first side of the first burst pattern by a distance not greater than the read width of a magnetic head and a fourth side opposed to the third side and spaced apart from the second side by a distance not greater than the read width. The first radial data structure generates a first signal for positioning the magnetic head relative to the recording medium.

Abstract: In a disk drive system, a circuit reduces the deterioration of the S/N ratio and corrects the position of a peak in a read signal to an accurate position. In one embodiment, a circuit senses the threshold levels corresponding to the magnitudes of three consecutive peaks of a read signal. A comparator obtains the direction of shift of the centrally positioned peak with respect to a reference position from the relationship of the magnitudes of the three consecutive peaks. The comparator outputs a pulse representing the direction of shift to a FIFO buffer. A delay circuit outputs a plurality of pulses. The pulses are shifted by an amount corresponding to a threshold level. A multiplexer selects a pulse to output from the delay circuit based on the direction of shift that was output from the FIFO buffer and based on the difference detected by an amplitude detection circuit. In an alternative embodiment, the correction circuit is implemented using a microprocessor.

Abstract: In a disk drive actuator head stack assembly, magnetic transducers including magnetoresistive (MR) read heads are connected to a current source and configured to provide an MR sensor current to each MR head wherein the direction of current flow for the MR sensor current in each MR head is the same relative to the actuator for all of the MR heads in the actuator head stack. This configuration allows all of the MR heads in the head stack assembly to be initialized simultaneously by applying a homogeneous magnetic field to the head stack assembly, thus providing the capability of initializing the MR heads at the actuator or disk drive level rather than requiring that the MR heads be initialized individually.

Abstract: Disclosed is a powder of silicon nitride particles having a specific surface area of from 5 to 20 m.sup.2 /g. When an aqueous solution of a polyvinyl alcohol having a mean degree of polymerization of X and a degree of saponification of Y (mol %) is adsorbed to the powder, the amount of saturated adsorption at 20.degree. C. is not higher than the amount of adsorption to be represented by:Amount of Adsorption (mg/m.sup.2)=0.000112X+0.523Y/100-0.207 (1)Also disclosed is a low-viscosity silicon nitride-containing aqueous slurry containing said powder.

Abstract: A system for processing image data of a text document in compressed form wherein pel signals of the original image are stored in pel positions in an input image buffer and the pel signals stored in every other pel (EOP) positions in the input buffer are sequentially fetched, along with respective pluralities of neighboring pel signals stored in EOP positions and compressed by adaptive arithmetic compression to generate a first set of compressed data which is stored in a memory. The pel signals stored in remaining pel (RP) positions in the input image buffer are also sequentially fetched, along with respective pluralities of neighboring pel signals, including at least one signal stored in an RP position and a plurality of signals stored in EOP positions, and compressed by adaptive arithmetic compression to generate a second set of compressed data which is stored in a memory.

Abstract: A method and apparatus for reducing or enlarging an image. More specifically, this invention can increase or decrease the magnification ratio of an image even while scanning each line. This invention involves converting a first image with a first pel density to a second image with a second pel density. The intensity P of a new pel at a point p of the second image is represented by ##EQU1## where m is the number of reference pels of the first image that are sampled and that are within a given two-dimensional reference window when it is in a predetermined position corresponding to the point p, where Ii is the intensity of the i-th pel of the m sampled reference pels, and where .alpha.i is a contribution rate indicating how much the i-th pel contributes to the intensity P. Pre-calculated contribution rate data (.alpha.i) and pre-calculated shifting amount data indicating the relative amount the reference window is to be shifted are stored in a memory.

Abstract: The invention directly controls the start of application of clock pulses to a shift register of an image sensor unit in synchronism with read signals supplied from a processor unit, to transfer video data of successive scan lines of an image. Transfer time of video data of one scan line from the shift register to the processor unit is compared to a predetermined time period. If the transfer time exceeds the predetermined time period, transfer of video data of the next scan line to the shfit register is allowed after the video data of the one scan line in the shift register has been transferred to the processor unit, whereby electric charges for the next scan line accumulated in the photodiodes are vanished. And, the video data of the next scan line in the shift register is discarded.

Abstract: An image processing system to allow communication with input and output devices having varying resolutions. An image processing system converts an image into a compressed base image and successive levels of error correction data so that an output of the image may be provided with any desired level of resolution (up to that of the input) with further levels of resolution obtained through predictive techniques. Advantageously, the error coding data is arithmetically coded.

Abstract: An image scaling method and apparatus partitions each line of image pel (print element) indicating bits into a number of bit groups equal to the number of bits to be added or deleted from the line to achieve a desired scaling. In each of the bit groups, one pel is added for enlargement or one pel is deleted for reduction. The pel addition or deletion occurs at pairs of like-pel indicating bits. If any bit groups has no pairs of like-pel indicating bits, a pel indicating bit is added for enlargement or deleting for reduction in an arbitrary location in the bit group.

Abstract: A seat suspension is disclosed in which a movable frame to be mounted onto a seat cushion for an automobile so as to be resiliently movable relative to a base frame mounted onto the floor surface of the automobile. The movable and base frames are connected with each other such that the movable frame can be moved elastically and vertically by means of two links mounted crosswise and pivotally and a spring constantly biasing these two links. Between the movable and base frames, there is provided a lock mechanism which is arranged to lock the movable frame at a desired height level. The lock mechanism includes a lock piece which is provided in either the base frame or the movable frame and has a plurality of engagement recesses in a vertical direction, and a lock pin which is provided in the other frame and is adapted to be engaged within the engagement recesses of the lock piece.

Abstract: In a process for preparing a diester of oxalic acid by the vapor phase catalytic reaction of carbon monoxide with an ester of nitrous acid in the presence of a catalyst composed of a solid carrier and a catalyst component supported on the carrier, the improvement wherein said catalyst component is composed of(a) a platinum-group metal or a salt thereof, and(b) at least one member selected from the group consisting of Ti and an oxide thereof.

Abstract: In a process for preparing a diester of oxalic acid by the vapor phase catalytic reaction of carbon monoxide with an ester of nitrous acid in the presence of a catalyst composed of a solid carrier and a platinum-group metal or a salt thereof supported on the carrier, the improvement wherein said solid carrier is alumina having a specific surface area of not more than 90 m.sup.2 /g.

Abstract: In a process for preparing a diester of oxalic acid by the vapor phase catalytic reaction of carbon monoxide with an ester of nitrous acid in the presence of a catalyst composed of a solid carrier and a catalyst component supported on the carrier, the improvement wherein said catalyst component is composed of(a) a platinum-group metal or a salt thereof, and(b) at least one metal selected from the group consisting of Mo and Ni, or a salt thereof.