Abstract: Servo-pattern information is magnetically recorded on a product disc by magnetic print-through from a master medium. The master servo-writing medium is brought into close proximity with the product “slave” disc, and the two are subjected to an external magnetic field which assists in transferring magnetic servo-patterns to the slave disc in a print-through process. The preferred external magnetic field alternates and rotates with respect to the master/slave combination. In an alternative product disc structure, the magnetic layer is magnetically altered in a servo-pattern configuration. Non-magnetic portions of the servo pattern are created which define both gray code and servo burst information for the product disc.

Abstract: Servo-pattern information is magnetically recorded on a product disc by magnetic print-through from a master medium. The master servo-writing medium is brought into close proximity with the product “slave” disc, and the two are subjected to an external magnetic field which assists in transferring magnetic servo-patterns to the slave disc in a print-through process. The preferred external magnetic field alternates and rotates with respect to the master/slave combination. In an alternative product disc structure, the magnetic layer is magnetically altered in a servo-pattern configuration. Non-magnetic portions of the servo pattern are created which define both gray code and servo burst information for the product disc.

Abstract: Servo-pattern information is magnetically recorded on a product disc by magnetic print-through from a master medium. The master servo-writing medium is brought into close proximity with the product "slave" disc, and the two are subjected to an external magnetic field which assists in transferring magnetic servo-patterns to the slave disc in a print-through process. The preferred external magnetic field alternates and rotates with respect to the master/slave combination. In an alternative product disc structure, the magnetic layer is magnetically altered in a servo-pattern configuration. Non-magnetic portions of the servo pattern are created which define both gray code and servo burst information for the product disc.

Abstract: Servo-pattern information is magnetically recorded on a product disc by magnetic print-through from a master medium. The master servo-writing medium is brought into close proximity with the product "slave" disc, and the two are subjected to an external magnetic field which assists in transferring magnetic servo-patterns to the slave disc in a print-through process. The preferred external magnetic field alternates and rotates with respect to the master/slave combination. In an alternative product disc structure, the magnetic layer is magnetically altered in a servo-pattern configuration. Non-magnetic portions of the servo pattern are created which define both gray code and servo burst information for the product disc.

Abstract: A barberpole magnetoresistive (MR) sensor has a series of permanent magnet strips interleaved with a series of magnetoresistive strips. Conductive barberpole strips are canted across the sensor and connect one magnetoresistive strip, over a permanent magnet strip, to another magnetoresistive strip. The permanent magnet strips help to provide a uniform magnetic field throughout the sensor, thereby making the sensor more immune to harm from an external magnetic field and more likely to reset into a single magnetic domain oriented as desired if an external magnetic field should cause the sensor to fracture into multiple magnetic domains.

Abstract: A magnetoresistive sensor (10) having permanent magnet stabilization includes a magnetoresistive layer (12), at least one permanent magnet (14a or 14b), and first and second current contacts (16a and 16b). The magnetoresistive layer (12) has an active sensing region (18) having a first thickness, and at least one under layer region (26a or 26b), with each under layer region (26a or 26b) having a second thickness that is less than the first thickness. Each permanent magnet (14a or 14b) is formed upon an under layer region (26a or 26b) of the magnetoresistive layer (12), and the first and second contacts (16a and 16b) are electrically coupled to the active region (18).

Abstract: An MR sensor having improved current density distribution, reduced overall resistance and a substantially planar surface is disclosed. The MR sensor includes an MR layer having first and second outer regions and an active region located between the first and second outer regions. A first permanent magnet region is formed upon the first MR layer outer region and defines a first boundary of the MR layer active region. A second permanent magnet region is formed upon the second MR layer outer region and defines a second boundary of the MR layer active region so that a gap region is positioned at least partially between the first and second permanent magnet regions. A spacer layer is formed on the MR layer active region between the first and second permanent magnet regions. A soft adjacent layer is formed in the active region and upon the spacer layer, and, in some preferred embodiments, also at least partially upon the permanent magnet region.

Abstract: An MR sensor having improved current density distribution, reduced overall resistance and a substantially planar surface is disclosed. The MR sensor includes an MR layer having first and second outer regions and an active region located between the first and second outer regions. A first permanent magnet region is formed upon the first MR layer outer region and defines a first boundary of the MR layer active region. A second permanent magnet region is formed upon the second MR layer outer region and defines a second boundary of the MR layer active region so that a gap region is positioned at least partially between the first and second permanent magnet regions. A spacer layer is formed on the MR layer active region between the first and second permanent magnet regions. A soft adjacent layer is formed in the active region and upon the spacer layer, and, in some preferred embodiments, also at least partially upon the permanent magnet region.

Abstract: A sputtering apparatus in which the electrode for supporting the substrates upon which thin magnetic films are to be deposited has a polygon-shaped planar coil adjacent to a surface so that the coil can be energized to produce a uniform magnetic field at the surface of the substrates which is oriented normal to the polygon faces of the coil. This apparatus produces uniform easy axis of the thin magnetic films deposited on the substrates during relative motion between the substrates and the target electrode.

Abstract: A magnetic bubble memory that can be read during every cycle of an in-plane drive field includes first and second minor loop sets into which alternate bits of a bubble pattern are stored. Two bubble generators are used to generate a sequence of bubbles in each of two associated lines for later movement to first and second write lines associated with the two minor loop sets, respectively. Swap functions are defined between each write line and the associated line and are operative in a push-pull manner to selectively move bubbles into alternative locations of each of the write lines. Later controlled movement of bubble patterns to selected locations in the minor loop sets results in permanent storage for later integration into a single read line for permitting "read-on-every-cycle" operation.

Abstract: A magnetic bubble memory of the G-shaped organization is implemented by ion-implantation. Attractive operating margins are realized by the use of transfer-out arrangements which moves bubbles in parallel first to an auxiliary path and thereafter to the major loop in a manner to invert the data.

Abstract: A magnetic bubble memory herein includes a direct propagation path between a bubble generator and a detector. A control circuit is adapted to store indications of the current state of the memory and the address of presently accessed data in the path responsive to a power failure signal. Portions of the memory are organized in a familiar major, minor mode, data from two major loops being replicated into the direct path.The arrangement exhibits improved access times, improved data rates and is secure from power failure problems. Moreover, the memory organization permits the realization of large capacity chips without requiring block replication.