Sony Corporation

Shigeyoshi Imakoshi

Hideo Suyama

Yutaka Soda

Tetsuo Sekiya

Hiroyuki Uchida

Yasuhiro Iida

Munekatsu Fukuyama

Hiroaki Yada

Junkichi Sugita

Masayuki Nakayama

Yutaka Souda

Hiroshi Takino

Toru Katakura

Takehiro Nagaki

Iwao Abe

Noboru Wakabayashi

Takeyuki Fuse

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.

Flux cancelling yoke type magnetic transducer head

A combination magnetic transducer head apparatus which can easily achieve initial formatting of data tracks of a rotating magnetic recording medium such as a hard disk without using a specific separate initial formatting system. The apparatus comprises a magnetic head for initial formatting, another magnetic head for servo control and a magnetic recording and playback head all mounted on a head slider. In the apparatus, at least one track is first recorded on a magnetic disk by the magnetic head for initial formatting and then another track is recorded by the magnetic recording and playback head while the first track is scanned by the magnetic head for servo control whereafter such a series of operations are repeated until completion of recording of all tracks required.

Magnetic transducer combination with formatting, data, and servo heads

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.

Magnetic transducer head utilizing magnetoresistance effect

A servo system for positioning a data transducer head relative to a plurality of substantially concentric data tracks on the surface of a magnetic disc including a pair of servo transducer heads for sensing the data tracks and generating output signals representative of a data signal written on the sensed track, a distance between the pair of servo transducer heads being related to the dimension of the data track and a distance between the servo transducer heads and the data transducer head being related to a data track pitch, a signal processing circuit connected to the pair of servo transducer heads for generating a data transducer head positioning signal and a positioning device for positioning the data transducer head in response to the transducer positioning signal and for maintaining the track centerline alignment of the data transducer head.

Tracking servo system for disc memory

A thin film type magnetic transducer head comprises a magnetic substrate, and a thin film magnetic core formed on the substrate through an effective magnetic gap at one end of the substrate to be faced to a magnetic recording medium, the magnetic substrate and the thin film magnetic core forming a magnetic circuit to reproduce signals on the magnetic medium, wherein a length between a center of the magnetic gap and an edge of the magnetic core and wave length satisfy definite relations, thereby the S/N ratio and the output are improved in the digital magnetic recording.

Thin film type magnetic transducer head

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.

A magnetic head utilizing the magnetoresistance effect comprising a magnetoresistance effect element and a conductor for applying a bias magnetic field to the element by being supplied with a bias current. The conductor is further supplied with a decaying alternating current superimposed on the bias current in advance of the playback operation, so that the hysteresis effect of the magnetic circuit is cancelled and the invariable output characteristics of the magnetic head are obtained.

A magnetic transducer head utilizing magnetoresistance effect having a circuit for applying a constant voltage to outer ends of at least one pair of magnetoresistance effect elements provided in series on a discontinuous portion other than a magnetic gap of a magnetic core forming a magnetic gap and a conductor arrangement for applying bias magnetic fields opposite in polarity to the magnetoresistance effect elements, respectively wherein an output is derived from a connected point between the pair of magnetoresistance effect elements.

Magnetic transducer head having series connected magnetroresistance

A multi channel magnetic transducer head comprises a magnetic substrate, and a plurality of thin film type magnetic transducer head elements arranged on the magnetic substrate, each magnetic transducer head element including a coil conductor disposed on the magnetic substrate and a thin film magnetic core to constitute a magnetic circuit in co-operation with the substrate, wherein a non-magnetic gap spacer layer with a predetermined thickness is formed at track width portion below front end of the thin film magnetic core on the magnetic core, a non-magnetic layer with thickness larger than that of the gap spacer layer is formed at track spacing portion, the thin film magnetic core has width covering at least the gap spacer layer of the track width portion, thereby good magnetic recording can be performed.

Multi channel magnetic transducer head

A magnetic transducer head utilizing a thin film magneto-resistance effect element is disclosed in which the amount of a DC bias magnetic field is so selected that only the end portion of the thin film magneto-resistance effect element serving as a contact surface with a magnetic medium is effectively given with sensitivity and the element is saturated in the vicinity of its central portion in its width direction.

Magnetic transducer head utilizing magneto resistance effect with a bias

A magnetic transducer head utilizing magnetoresistance effect is disclosed which includes a thin film magnetoresistance effect element held between, first and second substrates, at least one of the first and second substrates being formed of an electrically conductive material, and a biasing means for the magnetoresistance effect element to satisfy a potential relation V.sub.MR -V.sub.S .ltoreq.0.2 volt, wherein V.sub.MR is a potential of the magnetoresistance effect element, and V.sub.S is a potential of the conductive substrate.

Growing community of inventors

Kanagawa, Japan

Shigeyoshi Imakoshi