Tdk Corporation

Toshikazu Hosobuchi

Hideki Hirata

Giichi Shibuya

Yasufumi Takasugi

Kazuki Suzawa

Takashi Namioka

Kazuo Fukunaga

Katsumichi Tagami

Tsutomu Kotani

A magnetic memory is provided in which the margin between a write current and a read current can be reduced. A magnetic storage element includes: a first magnetic layer in which the direction of magnetization can be reversed; a second magnetic layer in which the direction of magnetization is fixed; and a non-magnetic layer which is interposed between the first and second magnetic layers. The write current and the read current are supplied to the magnetic storage element in the stacking direction thereof through a read-write line. Moreover, a bias line which can apply a bias magnetic field to the first magnetic layer during a reading operation is disposed in the vicinity of the magnetic storage element.

Magnetic memory and method for reading-writing information from-to magnetic storage element

A TMR element has a free first magnetic layer, a second magnetic layer with a magnetization direction B fixed, a nonmagnetic insulating layer provided between the first magnetic layer and the second magnetic layer, a third magnetic layer provided above a surface of the first magnetic layer and having a fixed magnetization direction, and a first nonmagnetic conductive layer provided between the first magnetic layer and the third magnetic layer, and an area of a cross section of the first magnetic layer perpendicular to a stack direction is not less than 0.001 &#x3bc;m, and less than 0.02 &#x3bc;m.

Magnetic memory

It is an object of the present invention is to provide an apparatus for discriminating an optical recording medium and a method for discriminating an optical recording medium which can reliably discriminate the kind of an optical recording medium even in the case where the optical recording medium to be discriminated is formed with periodical undulation in the circumferential direction thereof. The apparatus for discriminating an optical recording medium according to the present invention includes a first electrode, a second electrode, an alternate current signal generation circuitfor applying an alternate current A to the first electrode, a detection circuitfor detecting a level of an alternate current B appearing at the second electrode, and a control circuitfor controlling the operations of the alternate current signal generation circuitand the detection circuit

Apparatus for discriminating optical recording medium and method for discriminating optical recording medium

The present invention provides a method and an apparatus for discriminating the type of an optical recording medium and the number of recording layers in the medium. The apparatus includes a first electrode and a second electrode placed in the vicinity of a light transmission layer of the recording medium, an alternating current signal generation circuit for applying an alternating current A to the first electrode, a detection circuit for detecting the level of an alternating current B appearing at the second electrode, and a control circuit for controlling the operations of the alternating current signal generation circuit and the detection circuit, and a table provided in the control circuit.

It is an object of the present invention to provide an apparatus for discriminating an optical recording medium which can reliably discriminate the kind of an optical recording medium even in the case where the optical recording medium to be discriminated is warped and formed with periodical undulation in the circumferential direction thereof. The apparatusfor discriminating an optical recording medium according to the present invention includes a first electrodea second electrodea third electrodea fourth electrodean alternating current signal generation circuitfor applying an alternating current signal A to the first electrodeand the third electrodea detection circuitfor detecting the level of an alternating current signal Bappearing at the second electrodeand the level of an alternating current signal Bappearing at the fourth electrodea supporting mechanismfor supporting the first electrodeand the second electrodea supporting mechanismfor supporting the third electrodeand the fourth electrodea driving mechanismfor vertically moving the supporting mechanisma driving mechanismfor vertically moving the supporting mechanismand a control circuitfor controlling the operations of the alternating current signal generation circuitthe detection circuitthe driving mechanismand the driving mechanismand a tableis provided in the control circuit

It is an object of the present invention to provide an apparatus for discriminating an optical recording medium and a method for discriminating an optical recording medium which can reliably discriminate the kind of an optical recording medium even in the case where the optical recording medium to be discriminated is warped. The apparatus for discriminating an optical recording medium according to the present invention includes a first electrode, a second electrode, an alternating current signal generation circuitfor applying an alternating current signal A to the first electrode, a detection circuitfor detecting the level of an alternating current signal B appearing at the second electrode, a supporting mechanismfor supporting the first electrodeand the second electrode, a driving mechanismfor vertically moving the supporting mechanism, and a control circuitfor controlling the operations of the alternating current signal generation circuitand the detection circuitand the driving mechanism

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Tokyo, Japan

Toshikazu Hosobuchi