Abstract: The present disclosure generally relates to a magnetic recording system comprising a magnetic recording head. The magnetic recording head comprises a main pole disposed at a media facing surface (MFS). The main pole is disposed between a trailing shield and a leading shield, the trailing shield and the leading shield each extending to the MFS. A first lead is disposed between the main pole and the trailing shield, and the first lead is recessed from the MFS. A first portion of the first lead is disposed in contact with the main pole. A first insulating layer is disposed between and in contact with a second portion of the first lead and the main pole, and the first insulating layer being recessed from the MFS. The first lead and the first insulating layer direct a current through the main pole at a location recessed from the MFS.

Abstract: A surge protection device includes: a pair of terminal fittings to be connected to a pair of power supply terminals of a field device together with a power supply cable; a circuit board on which a surge protection element is mounted, the surge protection element including two electrodes connected to the pair of terminal fittings and a ground electrode configured to cause a surge current to flow to a ground when a surge voltage is applied between the two electrodes; an earth wiring cable connected to the ground electrode; and a main body that houses the circuit board, the main body being configured such that the pair of terminal fittings and the earth wiring cable protrude from an inside of the main body to an outside.

Abstract: An light emitting diode (LED) driving circuit for controlling a leakage current and compatible with a ballast includes: an input circuit including buffer capacitors CX1, CX2, CX3; discharging resistor strings RX1, RX2, RX3; fuses F1, F2, F3; piezoresistors VR1, VR2, VR3; a plurality of output terminals each of which comprising a first rectifying connection terminal; a second rectifying connection terminal; a third rectifying connection terminal; and a fourth rectifying connection terminal; and a plurality of input terminals each of which including a first electrical energy connection terminal; a second electrical energy connection terminal; a third electrical energy connection terminal; and a fourth electrical energy connection terminal; and a rectifying circuit connected to the input circuit; a power supply control module including a positive electrode connection terminal, a signal receiving terminal, a positive supply terminal, and a negative supply terminal.

Abstract: According to one embodiment, a magnetic recording head includes a magnetic pole, a stacked body, and a first non-magnetic layer. The stacked body includes a first magnetic layer, a second magnetic layer provided between the first magnetic layer and the magnetic pole, and a non-magnetic intermediate layer provided between the first magnetic layer and the second magnetic layer. The first non-magnetic layer is provided between the second magnetic layer and the magnetic pole, and contacts the magnetic pole and the second magnetic layer. The first magnetic layer has a first thickness and a first saturation magnetic flux density. The second magnetic layer has a second thickness and a second saturation magnetic flux density. A second product of the second thickness and the second saturation magnetic flux density is larger than a first product of the first thickness and the first saturation magnetic flux density.

Abstract: The present disclosure generally relates to a HAMR head and techniques and apparatus for HAMR writer pole length characterization. One or more bits may be magnetically written on a disk using a leading edge of the writer pole at a first polarity. The disk may be moved under a body of the writer pole to magnetically write the one or more bits in the disk at a second polarity that is opposite to the first polarity to generate a feedback pulse having a signal amplitude. The signal amplitude of the feedback pulse may be measured as a function of writing frequency. A first effective length of the writer pole may be determined based on the measurements.

Abstract: In one embodiment, a magnetic head includes a main pole configured to write data to a magnetic medium, a trailing shield positioned on a trailing side of the main pole, and a STO between the main pole and the trailing shield, wherein the STO includes a laminated structure having a FGL, a spun polarization layer (SPL), and a non-magnetic spacer positioned between the FGL and the SPL, wherein the FGL includes a laminated structure having one or more layers of a CoFe alloy and a Heusler alloy alternately laminated in this order from an end of the FGL closest to the non-magnetic spacer. In another embodiment, a method is presented for forming such a magnetic head utilizing a FGL that includes a laminated structure baying layers of a CoFe alloy and a Heusler alloy alternately laminated in this order from an end of the FGL closest to the non-magnetic spacer.

Abstract: A magnetic recording head for microwave-assisted magnetic recording is disclosed. In one embodiment, a magnetic recording head is for applying a magnetic field from a main pole of said magnetic recording head for recording data to a disk. Further comprising a spin torque oscillator adjacent to said magnetic recording head and is for generating a high-frequency magnetic field at a stable frequency and amplitude. Further comprising a capacitor connected to an upper electrode of said spin torque oscillator via a first resistor and a lower electrode of said spin torque oscillator via a second resistor.

Abstract: A magnetic recording system configured for recording to a bit patterned media using both hypertrack recording and shingled recording. The magnetic recording system includes a write pole with a notched trailing edge that results in a write bubble with a trailing edge that has two outer convex lobes separated by a centrally disposed concave region. By locating one of the lobes over first and second data tracks of a hypertrack, a proper alignment of the relative phase of the two tracks can be maintained. Further adjustment to the alignment can be achieved by adjusting the radial location of the write head.

Abstract: A disk drive read circuit is disclosed comprising a read element for generating a read signal, and a sense amplifier comprising an input terminal coupled through a first capacitor to the read element and an output terminal coupled through a second capacitor to a transmission line, wherein the sense amplifier is for amplifying the read signal.

Abstract: In one embodiment, a high-frequency magnetic field-assisted magnetic recording (MAMR) head includes: a yoke adapted for facilitating magnetic flux through the MAMR head; a main pole magnetically coupled to the yoke and adapted for producing a writing magnetic field; a return pole spaced from the main pole; a spin torque oscillator (STO) positioned above the main pole; and a back gap layer positioned between the yoke and the return pole, where at least one of the yoke, the main pole, the return pole, and the back gap layer comprises a highly resistive magnetic material.

Abstract: Amplifier architectures are provided for current sensing applications. An amplifier includes a load device, an operational amplifier, a current source, and a bipolar transistor. The operational amplifier has a first input terminal connected to a first input node that receives an input current, and a second input terminal connected to a second input node that receives a reference voltage. The current source is connected to an output of the operational amplifier. The operational amplifier, the current source, and the bipolar transistor form a feedback loop that generates and maintains a bias voltage on the first input node based on the reference voltage applied to the second input node. The bipolar transistor amplifies the input current received on the first input node, and generates an amplified input current. The load device converts the amplified input current to an output voltage, wherein the output voltage is used to sense the input current.

Abstract: An example magnetic recording apparatus includes a magnetic recording medium and a magnetic recording head. The magnetic recording head includes a first magnetic pole to apply a recording magnetic field to a magnetic recording medium, a spin torque oscillator provided parallel to the first magnetic pole, a first coil which surrounds the first magnetic pole, to magnetize the first magnetic pole, and a second coil to pass a current independently of the first coil and magnetize the first magnetic pole. A signal processor writes and reads a signal on the magnetic recording medium by using the magnetic recording head.

Abstract: A hard disk drive or other disk-based storage device comprises a storage disk, a write head configured to write data to the disk, and control circuitry coupled to the write head. The control circuitry comprises a write driver and degauss circuitry associated with the write driver. The degauss circuitry is configured to generate a chirped degauss signal to be applied to the write head by the write driver. The degauss circuitry comprises a ramp generator configured to generate a ramp signal for controlling a frequency of at least a portion of a waveform of the chirped degauss signal. The ramp signal generated by the ramp generator may comprise a current ramp that is applied to a control input of a current controlled oscillator of the degauss circuitry.

Abstract: A hard disk drive or other disk-based storage device comprises a storage disk, a write head configured to write data to the disk, and control circuitry coupled to the write head. The control circuitry comprises a write driver and degauss circuitry associated with the write driver. The degauss circuitry is configured to generate a degauss signal to be applied to the write head by the write driver. The degauss signal has a waveform comprising a plurality of decay segments including at least one alternating current decay segment and at least one direct current decay segment. An initial decay segment of the plurality of decay segments may comprise an alternating current decay segment or a direct current decay segment, and may be immediately followed by a decay segment of the opposite type.

Abstract: A hard disk drive or other disk-based storage device comprises a storage disk, a write head configured to write data to the disk, and control circuitry coupled to the write head. The control circuitry comprises a write driver and degauss circuitry associated with the write driver. The degauss circuitry is configured to generate a chirped degauss signal to be applied to the write head by the write driver. The degauss circuitry comprises a ramp generator configured to generate a ramp signal for controlling a frequency of at least a portion of a waveform of the chirped degauss signal. The ramp signal generated by the ramp generator may comprise a current ramp that is applied to a control input of a current controlled oscillator of the degauss circuitry.

Abstract: A magnetic tape medium includes at least one servo band along a longitudinal extension of the tape medium which at least one servo band comprises servo patterns organized in servo frames for supporting to determine positional information. At least one of the servo frames includes a first burst comprising at least two servo stripes inclined at a first angle with respect to a direction orthogonal to the longitudinal extension of the tape medium, followed by a second burst including at least two servo stripes inclined at a second angle with respect to a direction orthogonal to the longitudinal extension of the tape medium, which second angle is different from the first angle. At least one of the stripes of the first burst has a first magnetic polarity and at least one of the stripes of the second burst has a second magnetic polarity different from the first magnetic polarity.

Abstract: There are provided a magnetic recording medium and a magnetic memory device capable of implementing high recording density, in the case of using a microwave assisted magnetic recording (MAMR) scheme. In a magnetic memory device including a magnetic recording medium having a recording film with three or more layers, a recording magnetic pole generating a recording magnetic field, an opposed magnetic pole, a high frequency magnetic field generating element generating a microwave for recording assist, and a magnetic reproduction element, an anisotropic field of a first layer which is a top layer of the recording film is larger than 20 kOe.

Abstract: A system comprises a first tapered core configured for positioning adjacent a first surface of a magnetic medium, and a second tapered core configured for positioning adjacent a second surface of the magnetic medium, opposite the first tapered core along a travel direction of the magnetic medium. Each of the first and second tapered cores has a transverse width defined with respect to the magnetic medium, where the transverse width decreases from a first end of the tapered core to a second end of the tapered core, the second end forming a pole face adjacent the magnetic medium.

Abstract: The present disclosure relates to a perpendicular pole head for creating a perpendicular magnetic moment in a concentrated pattern for writing the pattern on perpendicular magnetic media, such as BaFe based media. The pole head can have flux concentrators in the shape of the written pattern, which can be repeatedly applied to a moving magnetic medium to create a timing pattern on the media, e.g., a servo timing pattern.

Abstract: According to one embodiment, a magnetic head includes a main pole configured to apply a perpendicular recording magnetic field to a recording layer of a recording medium, a return pole opposed to the trailing side of the main pole with a write gap therebetween and configured to reflux magnetic flux from the main pole to form a magnetic circuit in conjunction with the main pole, a coil configured to excite magnetic flux in the magnetic circuit includes the main pole and the return pole, a plurality of high-frequency oscillatory elements individually interposed between the main pole and the return pole, includes a plurality of magnetic films different in magnetic resonance frequency, and configured to individually apply high-frequency magnetic fields to the recording medium, and an electrical circuit configured to energize the high-frequency oscillatory elements.

Abstract: According to one embodiment, a recording head for perpendicular recording, includes a main pole configured to apply a recording magnetic field to a recording layer of a recording medium, a return pole opposed to the main pole with a write gap therebetween and configured to form a magnetic circuit in conjunction with the main pole, a junction formed of a nonmagnetic body in which soft magnetic bodies are dispersed and configured to physically connect the main and return poles to each other, a coil configured to excite the magnetic flux in the magnetic circuit, a spin-torque oscillator arranged between the return pole and an end portion of the main pole and configured to produce a high-frequency magnetic field, and a current source configured to supply a current to the spin-torque oscillator through the return and main poles.

Abstract: Planar magnetic heads and methods of making the same using a built-up approach and thru-hole via technology to achieve a true planar head. A head may comprise a substrate having conductive thru-hole vias extending therethrough, a first magnetic layer deposited and patterned on the substrate, a first insulation layer deposited and patterned on the first magnetic layer, a conductive coil layer deposited and patterned on the first insulation layer and connected to the conductive thru-hole vias, a second insulation layer deposited and patterned on the conductive coil layer, vias patterned into the insulation layer extending to the first magnetic layer, a second magnetic layer deposited in the vias, and a third magnetic layer deposited and patterned on the second insulation layer and second magnetic layer. The third magnetic layer may be connected to the first magnetic layer through the second magnetic layer deposited in the vias of the insulation layers.

Abstract: A pole layer has a track width defining portion and a wide portion. The pole layer has: first and second side surfaces located opposite to each other in a first region extending from a medium facing surface to a position at a distance of 10 to 300 nm from the medium facing surface; third and fourth side surfaces located in a second region other than the first region; a fifth side surface located at the boundary between the first and second regions and connecting the first and third side surfaces to each other; and a sixth side surface located at the boundary between the first and second regions and connecting the second and fourth side surfaces to each other. The distance between the first and second side surfaces taken in the track width direction decreases with decreasing distance from the top surface of the substrate.

Abstract: An IC chip for a magnetic impedance (MI) sensor includes an MI element electrode, a switch unit, and a power supply electrode, wherein the MI element electrode is disposed in the neighborhood of a first side face of the IC chip, and the power supply electrode is disposed in the neighborhood of a second side face opposite the first side face. A power supply voltage is provided to the switch unit through the power supply electrode, and a high frequency pulse exciting current is provided to the MI element through the MI element electrode. Since the first power supply electrode and the MI element electrode are disposed at a distance, noise generated by the high frequency pulse exciting current is prevented from superposing the signals of circuits other than the switch unit.

Abstract: The present invention relates to computer storage systems which have a tip (24) directed close or in contact to the storage medium (10) by which bit-writing and bit-reading is enforced. It is proposed to use a magnetizable storage medium (10), expose it to an artificial, external magnetic field H coupled externally to the storage medium, and—during bit writing—to concurrently apply heat very locally in bit size dimension in order to let the external magnetic field become locally larger than the (temperature-dependent) coercive field at the location (32) where heat is applied.

Abstract: A shielded magnetic head includes a magnetically shielded gap and first to fourth conductive magnetic films disposed in the gap. The first to fourth conductive magnetic films, each extending parallel to a tip face of a magnetic head to be opposed to a magnetic recording medium, are aligned at a distance from one another in a direction perpendicular to the tip face so as to be away from the tip face in ascending order and connected to one another so as to form a bridge circuit. The distance between the first conductive magnetic film and the tip face is set so that a signal magnetic field from the magnetic recording medium is applied to the first conductive magnetic film. By canceling impedance components that do not vary depending on a magnetic field, the shielded magnetic head detects only impedance components that vary depending on a signal magnetic field.

Abstract: A method is provided for generating a composite video data stream. A first data stream composed of a sequence of frames of video data each having an x-dimension of a preselected number of pixels and a y-dimension of a preselected number of pixels is received. A second data stream composed of a sequence of frames of video data each having a x-dimension of a preselected number of pixels and a y-dimension of a preselected number of pixels is also received. The x- and y-dimensions of the frames of the first data stream are downscaled to produce a sequence of first blocks of pixels. The x- and y-dimensions of the frames of the second data stream are downscaled to produce a sequence of second blocks of pixels. The first blocks are written into a first object buffer associated with a first memory space during first and third ones of four processing phases using a set of counters associated with the first object buffer.

Abstract: In a data recording and reproducing apparatus for writing the video signals read out from a magnetic tape (11) alternately into image memories, and reading out and reproducing the video signals from the image memory not used for writing video signals, the video signal read out from the image memory when the memory indication switch (SW1) is manipulated is directly held in the image memory, and when reproducing the video signal executed in succession, using the image memory in which video signals is not preserved, writing of video signal from the magnetic tape (11) into image memory and reading from the image memory are effected. In this reproducing action, when the reproduction indication switch (SW2) is manipulated, and previously preserved video signal is read out from the image memory and reproduced.

Abstract: A magnetic recording and reproducing apparatus for recording and reproducing plural types of data signals respectively different in data rate, and capable of completely eliminating noise when reproducing data signals of high data rate or low data rate at slower or faster speed than normal speed.

Abstract: An apparatus for recording high resolution image data, which is inputted from the external at a predetermined timing, to a recording medium of random access type, is provided with: a memory for storing at least one high resolution image data by a unit of picture plane on the basis of a record control signal; a device coupled to the memory, for dividing and converting the high resolution image data stored in the memory into a plurality of standard image data corresponding to a standard television system one after another; a recording device coupled to the dividing and converting device, for recording the plurality of standard image data to the recording medium by a unit of field or frame; and a control device for generating the record control signal, which corresponds to the predetermined timing of the high resolution image data.

Abstract: A magnetic recording and reproducing apparatus capable of recording video, audio and other information on a magnetic tape by, for example, the helical scanning method. A rotary head is rotated at an m-fold speed to record intermittent tracks on the magnetic tape so that real-time simultaneous monitoring is performed. By high-speed dubbing due to high-density intermittent recording and by increasing the number of repetition of track scanning, the information is recorded and reproduced simultaneously with a plurality of channels. Any tracking error is detected to form a continuous and uniform track pattern. With this intermittent comb-shaped recording, reciprocating recording and reproducing can be realized.

Abstract: In a recording apparatus for information recording in succession in plural memory blocks with a predetermined recording speed, a switch is used for selecting either a first recording mode for information recording in the plural memory blocks so as to form unrecorded ones and recorded ones in mixed manner, or a second recording mode so as not to form such mixed ones, and a control unit controls the recording speed according to the switching state of the switch.

Abstract: A time lapse VTR carrying out field extraction recording includes a gate for extracting intermittently a supplied video signal at a ratio of one field to every three fields, a switching circuit for designating selectively a tape running speed of either 1/9 or 1/12 the tape running speed of a SP mode in the VHS system, and a servo control circuit for driving a capstan motor to run a magnetic tape at the designated tape running speed. The video signal extracted intermittently by the gate circuit is recorded at an azimuth angle differing from each field by a plurality of video heads on a magnetic head running at the designated tape running speed. As a result, the reproduction compatibility of a magnetic tape having field extraction recorded by a time lapse VTR with an EP mode of a conventional VTR of the VHS system is ensured.

Abstract: A digital recording system contained in each video frame in memory at a we rate equal to that of a video imager from which the system receives the information. The system then outputs the information from memory to a recorder at a read rate which can be below the write rate and maximum recorder rate. The system outputs information from memory at the lower read rate by skipping a specific number of entire video frames and outputting the video frames between those skipped. The read rate is selected so that it provides a continuous stream of data to the recorder with only short gaps between video fields.

Abstract: A magnetic recording and reproducing head records a signal from and reproduces a signal from a magnetic recording medium having a perpendicularly magnetizable film. The magnetic recording and reproducing head includes a magnetic sensing section comprising a slender needle of a soft magnetic material, and an exciting coil wound around the slender needle for magnetizing the slender needle to record a signal on the magnetic recording medium. To reproduced the recorded signal, high-frequency electric energy is applied to the magnetic sensing section to produce a reflected wave, and a change in the reflected wave caused by a leakage magnetic field produced by a signal recorded on the magnetic recording medium is detected as representing the recorded signal.

Abstract: An audio signal of arbitrary length is recorded on a single track of a magnetic disk, and a plurality of corresponding or associated video signals are recorded on successive coaxial tracks. The deviation of each video signal is counted during the reception of the audio signal, and data representative thereof is superposed on the recorded video signals to "coordinate" subsequent playback.

Abstract: A method of reproducing video signals from a magnetic recording medium like a magnetic tape for a VTR to obtain high-quality video pictures even when dropouts occur in the medium, which includes the steps of separating synchronizing information from the video signals reproduced from the magnetic recording medium, detecting a dropout duration from the reproduced video signals, generating complete synchronizing information during a whole period of writing the signals in image information memories by compensating lost synchronizing information during the dropout, generating write address signals on the basis of the generated synchronizing information, writing reproduced video signals the memories on the basis of the generated write address signals while no dropout occurs, and leaving unchanged previously written video signals while a dropout occurs. According to an apparatus implementing the above method, reproduced pictures of high quality are obtained without jitters and skews due to dropouts.

Abstract: A record and playback system comprises a signal source such as a video camera, a recording apparatus such as a VTR, and a control circuit device connected between the signal source and the recording apparatus. The control circuit device sends one or a few frames selected from a plurality of still picture frames to the successive frames of a composite picture signal given from the signal source to the recording apparatus, as well as sends a signal showing the total time length of a number of still picture frames. As a result, it is possible to record much and various picture information on a small volume of a record medium.

Abstract: A fast frame recorder records images of an event at a fast frame rate and plays back the images at a slower frame rate to facilitate analysis of the event. Disclosed is a solid state fast frame recorder having a solid state imager, which is selectively operable at different frame rates and having a solid state memory for storing a plurality of image frames. A programmable control system controls the memory to store temporally nonconsecutive images from the imager according to a preselected program. Both temporally nonconsecutive single image frames and bursts of temporally consecutive image frames may be stored. The number of image frames in a stored burst and the frame rate of the stored burst may be selectively varied.

Abstract: A method of flux conduction comprising providing a structure with anisotropy not purely in the transverse in-plane direction such that flux spreading into the transverse in-plane direction can occur by rotation.This method of flux conduction is used in magnetic devices having coupled magnetic layers or coupled magnetic domains. Devices disclosed which utilize this method can function as a magnetic recording head, bubble memory, magnetic field structure, magnetic field sensor, transformer, laminated magnetic memory element or magnetic shield.

Abstract: One aspect of the invention is a method of flux conduction comprising providing a structure with anisotropy not purely in the transverse in-plane direction such that flux spreading into the transverse in-plane direction can occur by rotation. Apparatus includes a thin film magnetic recording device having at least one pole with two magnetic layers and capable of conducting signal flux, a first of the magnetic layers having domains oriented in a first direction, a second of said magnetic layers having domains oriented in a second distinct direction, the layers coupled to each other such that signal flux can flow therebetween. Method of making and various embodiments disclosed.

Abstract: A picture signal source (PSS) comprises an encoding circuit (ENC) for encoding a picture signal having a higher bandwidth to a picture signal having a lower bandwidth. Encoding is effected in dependence upon the extent of motion in the picture which is determined by a motion detection device (MOT). An encoding has been given as an example, using several picture signal channels (PC1, PC2, PC3) each having a different picture signal refreshing period of, for example 80, 20 or 40 ms. The so-called field skipping method is used for which a switching circuit (SC4) switching at the frame frequency is provided. The picture display device (PDD) comprises an essentially complementary, inversely operative decoding circuit (DEC) with a motion-compensated (VR') picture signal interpolation circuit (MEM, INT, G) which comprises a gamma compensation circuit (G) according to the invention. Without this circuit a troublesome area flickering may occur upon display in practice.

Abstract: A thin film magnetic read/write head is conditioned by (i) causing the head to perform a first operation (e.g., a read operation), (ii) determining if the first operation was performed acceptably, and (iii) if not, causing the head to perform a second operation (e.g., a write operation) that is capable of increasing the likelihood that the head will be able to perform the first operation acceptably.

Abstract: A device for measuring a weak magnetic field is disclosed. The device includes a substrate, a magnetic core having a high magnetic permeability and in the form of a surface film on a substrate, and at least two coils magnetically coupled to the magnetic core. A pulse generator is connected to one of the coils and is used to drive the magnetic core into intermittent saturation. The other coil is used to generate an output signal. The device can be used for measuring the weak magnetic fields associated with bank notes for identifying the values of the bank notes.

Abstract: In processing a video signal reproduced from a track of a magnetic disc (10), if the reproduction video signal, from one track of the frame recorded on two adjacent tracks, is stored in a memory (34), then the control circuit (20) determines whether the memory (34) should be used as a field memory or a frame memory based on a field/frame discriminating signal reproduced from the reproduced track. Therefore, error which occurs when only one of the two tracks is erased, can be prevented.

Abstract: Propanol derivatives of formula (I) wherein X is a leaving group; R.sub.1 is H or a protecting group; and R.sub.2 is H, and R.sub.3 is a group--CH.sub.2 Y wherein Y is a leaving group; or R.sub.2 and R.sub.3 together form .dbd.CH.sub.2. The propanol derivatives of the formula (I) are useful as multifunctional alkylating agents.

Abstract: Plural magnetic transducing heads are employed to record and reproduce video information that is stored in a segmented format. One head is in contact with the magnetic recording tape while the other head is out of contact with it. The position of the head which is in contact with the tape is controlled by a suitable ramp voltage generated in accordance with the ratio of actual tape speed to normal play speed, to maintain the head generally aligned with a track on the tape. The other head, which is out of contact with the tape, is also positioned in the same fashion. When a repositioning of the heads is required, a determination is made whether the track of information being reproduced by the head in contact with the tape relates to a particular segment of a field, for example the last field.

Abstract: A skip-field guard-bandless video tape recorder records and plays back adjacent tracks on a video tape with two closely adjacent heads of opposing head gap azimuth angles (to suppress cross-talk), only during alternate (odd) half-rotations of the head drum. Unavoidable cross-talk of synchronization pulses from adjacent tracks does not create visible interference or timing errors during playback by virtue of a special offset angle .theta..sub.1, between the adjacent recording heads, proportional to the linear offset distance between adjacent tracks. During playback, skipped fields are "filled-in" by a repetition of each recorded field through a second (duplicate) pair of closely adjacent heads of opposing azimuth positioned to retrace the recorded tracks during the other alternate (even) half-rotations of the head drum. An offset angle .theta..sub.2 between the two head pairs (i.e.

Abstract: A still picture recording/reproducing device using a recording disk. For still picture reproduction, a manual selection is made as to whether a field or a frame is to be reproduced. The selected quantity is read from the disk and stored in a memory from which it is repeatedly read out for still picture display.

Abstract: A device for measuring a weak magnetic field is disclosed. The device includes a substrate, a magnetic core having a high magnetic permeability and in the form of a surface film on a substrate, and at least two coils magnetically coupled to the magnetic core. A pulse generator is connected to one of the coils and is used to drive the magnetic core into intermittent saturation. The other coil is used to generate an output signal. The device can be used for measuring the weak magnetic fields associated with bank notes for identifying the values of the bank notes.