Abstract: A method for driving a magneto-resistive effect element in which a bias magnetic field is applied by a bias conductor fed with a bias current to a magneto-resistive effect element whose resistivity is changed with an impressed magnetic field, wherein the improvement comprises supplying to said bias conductor a pulsed initial current having a pulse crest value higher than the bias current value prior to supplying said bias current. The MR head can be operated with MR characteristics with stable output and with highly sensitive MR characteristics.

Abstract: A recording/reproducing apparatus for a magneto-resistive (MR) head having a playback amplifier, including a capacitor for a dc feedback low-pass filter for dc feedback to an initial-stage transistor, and a differential amplifier (gm amplifier), and a switching device for the gm amplifier and for the initial-stage amplifier operable at the time of recording/playback switching. The timing of the switching device is deviated for shortening the switching time interval. To this end, an output of the initial-stage transistor of a playback amplifier for a MR head is compared to reference voltage Vref by a gm amplifier and the low-pass filter is constituted by transconductance gm of the gm amplifier and the capacitance of the capacitor, with the dc output of the gm amplifier being fed back to the base of the initial-stage amplifier.

Abstract: A magnetoresistance effect type thin film head (A) constructed in a manner that a magnetoresistance effect element, that is, an MR element (1) is disposed perpendicularly to a head surface a, and among two electrodes (2a) and (2b) led out from both ends of the MR element (1), the one electrode (2a) is exposed to the head surface a but the other electrode (2b) is not exposed to the head surface a, wherein the one electrode (2a) exposed to the head surface a is connected to a ground voltage Vss, thereby decreasing the change in voltage difference between the electrode (2a) of the MR element (1) and a disc surface b to prevent the electrical breakdown of the thin film head (A).

Abstract: A magnetoresistive element of a magnetoresistive head is connected to the emitter of a first-stage transistor which serves as a common base amplifier. A base current supplied to the base of the first-stage transistor is adjusted to equalize a sensing current to an emitter current. A reproducing circuit of such an arrangement requires no sensing current source and no DC blocking capacitor.

Abstract: An analog/digital compatible reproducing system is disclosed, particularly a stationary head system using a digital recorded magnetic tape having a plurality of n, digital data recorded tracks. An analog recorded magnetic tape has a first analog recorded track and a second analog recorded track between which a guardband of a certain width is provided. Signals are reproduced from the digital recorded magnetic tape by driving n reproducing magnetic head elements respectively corresponding to the n digital data recorded tracks. The analog recorded magnetic tape is reproduced by driving a plurality of m reproducing magnetic head elements of said n reproducing, magnetic head elements, corresponding to the first and second recorded tracks so that common outputs can be produced from the m reproducing magnetic head elements. There is also disclosed a tape cassette used in such system.

Abstract: Apparatus is provided for reproducing either M channels of digital audio signals recorded in longitudinal tracks on a record medium or an analog audio signal recorded in one or two stereo tracks. M heads are used to reproduce the M channels of digital audio signals and N of those heads (N.ltoreq.M) are used to reproduce the analog audio signal. The reproduced digital or analog audio signals are multiplexed and digitized. When digital audio signals are reproduced, the digitized multiplexed signals are digitally processed and then converted to analog form. When analog audio signals are reproduced, the digitized multiplexed signals are summed such that signals reproduced by the N heads are combined to form a digital representation of the recorded analog audio signal. The summed signals then are converted to analog form to recover the original analog audio signal.

Abstract: A yoke type magnetic transducer head utilizing a magnetoresistance effect in which a magnetoresistance effect sensing portion is provided so as to magnetically couple a cut-away portion in a magnetic circuit including an operation gap and a magnetic yoke having in its one portion the cut-away portion and in which a first bias magnetic field is applied to the magnetoresistance effect sensing portion by a first magnetic flux that is generated when a current is flowed through the magnetoresistance effect sensing portion, or when a current is flowed through both the magnetoresistance effect sensing portion and a bias conductor, which includes a hard magnetic layer for generating a second magnetic flux by which a second bias magnetic field is applied to the magnetoresistance effect sensing portion and for passing through the magnetic yoke a magnetic flux which cancels at least a part of the first magnetic flux which passes through the magnetic yoke.

Abstract: A magnetoresistance effect type magnetic transducer head apparatus comprises a magnetoresistance effect sensing element, means for applying a high-frequency magnetic field to the sensing element, means for taking-out an output signal from the sensing element, a filter for taking-out the high-frequency component of the output, and another filter for rectifying the output and taking-out the low-frequency component. The magnetic head apparatus may be constructed as a digital circuit so that a multi-channel apparatus can be easily implemented.

Abstract: A magnetoresistance effect type magnetic head apparatus has a magnetoresistance effect sensing element, means for applying a bias magnetic field to the sensing element, a detecting circuit for obtaining a detecting signal, a low pass filter for deriving an unwanted signal component from the detecting signal, and means for applying a cancelling magnetic field to the sensing element so as to eliminate the unwanted signal component. An additional sensing element may also be provided to detect an external magnetic field, and a corresponding signal is generated which is applied to a first sensing element so as to cancel the effects of the external magnetic field.