Abstract: A perpendicular magnetic recording apparatus includes a perpendicular double-layer film medium including a stack of a soft magnetic backing layer and a perpendicular magnetic recording layer in which recording is performed under a condition that a recording track pitch as a total of a recording track width and a guard-band width between recording tracks is set to be 1 &mgr;m or less, and a perpendicular magnetic recording head including a recording main pole, an auxiliary pole disposed at a gap having a length of five or less times the guard-band width with respect to the recording main pole, and an exciting coil.

Abstract: A perpendicular magnetic recording apparatus includes a magnetic disk having a perpendicular double-layer film and a perpendicular magnetic recording head having a leading pole positioned forward along the head traveling direction, a trailing pole positioned backward along the head traveling direction at a gap length from the leading pole and having, in an air-bearing surface, a forward pole and a rearward pole of which saturation magnetic flux density is higher than that of the forward pole, and an exciting coil. A length p of the trailing pole along the head traveling direction is longer than a length T of the trailing pole in a track width direction, the length p is longer than the gap length g1, and a length p1 of the rearward pole is shorter than a length p2 of the forward pole along the head traveling direction.

Abstract: A perpendicular magnetic recording apparatus includes a magnetic disk having a perpendicular double-layer film and a perpendicular magnetic S recording head having a leading pole positioned forward along the head traveling direction, a trailing pole positioned backward along the head traveling direction at a gap length from the leading pole and having, in an air-bearing surface, a forward pole and a rearward pole of which saturation magnetic flux density is higher than that of the forward pole, and an exciting coil. A length p of the trailing pole along the head traveling direction is longer than a length T of the trailing pole in a track width direction, the length p is longer than the gap length g1, and a length p1 of the rearward pole is shorter than a length p2 of the forward pole along the head traveling direction.

Abstract: A perpendicular magnetic recording apparatus includes a perpendicular double-layer film medium including a stack of a soft magnetic backing layer and a perpendicular magnetic recording layer in which recording is performed under a condition that a recording track pitch as a total of a recording track width and a guard-band width between recording tracks is set to be 1 &mgr;m or less, and a perpendicular magnetic recording head including a recording main pole, an auxiliary pole disposed at a gap having a length of five or less times the guard-band width with respect to the recording main pole, and an exciting coil.

Abstract: Bidirectional transmission of write and read data is effected between a reader/writer unit and a memory module in a contactless manner using electromagnetic induction coupling. A single magnetic induction coupling apparatus is provided for each of the reader/writer unit and the memory module. In the electromagnetic induction coupling apparatus of the reader/writer unit, a transmitting coil and a receiving coil are coaxially wound around a single magnetic core. In the electromagnetic induction coupling apparatus of the memory module, a single coil which is commonly used for transmission and reception is wound around a single magnetic core. A reception signal of the transmitting/receiving coil of the memory module is rectified and smoothed by a power source circuit, thereby forming an operating power source of the memory module. The power source circuit has a backup capacitor.

Abstract: The bidirectional transmission to write or read out data is executed between a read/write unit and a memory module by the contactless electromagnetic coupling using induction coils. A spread spectrum communication technique is used in at least the up transmission to transmit data from the memory module to the read/write unit in the bidirectional transmission. Two kinds of chirp waves or M series having little correlation are used in the spread spectrum communication. For instance, in the case of using the chirp waves, on the transmission side, two kinds of chirp waves having little correlation are prepared and either one of the chirp waves is transmitted in correspondence with the data bit 0 or 1. On the reception side, the correlation between the reception signal and each of the reference values of the two kinds of chirp waves which have previously been stored is calculated and the data bits 0 and 1 are demodulated on the basis of the result of the calculation.

Abstract: In response to a bit transfer request from one of two units, bit data is transmitted bit by bit from the other of the two units. The unit on the transmission side for transmitting the bit data has an M-series generator. In response to bit 1, a first M.sub.0 -series signal of a 63-word length is generated. In response to bit 0, a second M.sub.0 -series signal in which the series start position is set to the intermediate position of the first M.sub.0 -series signal, although the signal is the same M.sub.0 -series signal of the 63-word length, is generated. The unit on the reception side has previously stored the first and second M.sub.0 -series signals on the transmission side as reference signals, and calculates the correlations between the two reference signals and the reception signal, and demodulates the data bit corresponding to the reference signal having a larger correlation value.

Abstract: A control signal used to write access or read access and data are transmitted between a write/read unit and a memory module by a contactless coupling using induction coils. The write/read unit multiplexes a control signal consisting of three signals including a power source signal, sync clocks, and enable clocks using frequency modulation and supplies the resultant multiplexed signal to one end of the induction coil for transmission. The write/read unit frequency modulates access data and supplies same to the other end of the same induction coil for transmission. The transmitting coil in the memory module allows the signal which is obtained by adding an access signal to the control signal to be induced in the coil for reception in the write/read unit. The read data from the memory module is frequency modulated and sent from the memory module to the write/read unit by using the transmitting and receiving coils for a down-signal which is used only to read out data.

Abstract: Between two units which are separately arranged, a power source signal is supplied from one of the two units to the other unit via electromagnetic induction coupling by using induction coils, and data signals are mutually transmitted and received between both of the units. A change in coupling distance between the induction coils provided for the two units is detected from a signal level of a reception signal from the unit which receives the power supply. When the reception signal level decreases, the signal level of the power supply signal is increased.

Abstract: Vehicle information such as vehicle speed, engine rotational speed when a vehicle runs are collected and converted into numerical data every constant period of time and these numerical data are written and recorded into a memory module. The memory module has therein a non-volatile memory and is detachably provided to a write unit attached to the vehicle. The data writing and power supply to the memory module from the write unit are executed by the contactless coupling using induction coils.

Abstract: A tool holder is enclosed in a rack which is moved by a belt for automatic tool exchange. A stopper member provided for the rack is fitted into a positioning groove formed in a flange portion of the tool holder, thereby preventing the rotation of the holder. A magnetic induction coupling apparatus is buried in the bottom of the tool holder positioning groove. A magnetic induction coupling apparatus of a reader/writer disposed at the external position is arranged so as to face the magnetic induction coupling apparatus of the tool holder. Information is written into or read out of a memory module attached in the tool holder by way of the magnetic induction coupling between both of those coupling apparatuses. The stopper member of the rack is arranged between the magnetic induction coupling apparatus of the tool holder and the magnetic induction coupling apparatus of the reader/writer and has a magnetic material to magnetically couple these coupling apparatuses.

Abstract: Drive data such as vehicle velocity, engine rotational speed, and the like are recorded into a memory module in a state in which the memory module is attached to a vehicle. When drive management data is made, the memory module is detached from the vehicle and set to a read unit. When the read unit reads out the drive data recorded in the memory module, the drive management data such as drive period of time, rest period of time, maximum drive speed, drive distance, and the like are calculated on the basis of the readout data. The drive records classified every driver or every vehicle are automatically made.

Abstract: The bidirectional transmission for reading and writing data is performed between a write/read unit and a memory module using the contactless induction coupling of induction coils. The write/read unit frequency multiplexes a power source signal, a sync clock, and an enable clock and transmits the frequency multiplexed signals to the memory module. The memory module rectifies the received frequency multiplexed signals to produce an operating power source and to reproduce the sync clock and enable clock and to form an enable signal from the OR of both clocks. The write and read access information transmitted through another route is read in response to the reproduced sync clock and enable signal, thereby executing the writing and reading operations of a non-volatile memory.