公开(公告)号：JPS60119648A

公开(公告)日：1985-06-27

申请号：JP22815683

申请日：1983-12-02

Applicant: SONY CORP

Inventor： ASO KOUICHI ,  OCHIAI YOSHITAKA ,  SUGIURA GIICHI

IPC: G11B11/10 ,  G11B11/105 ,  G11C13/06

Abstract: PURPOSE:To improve the S/N by forming a soft magnetic thin film through coating transparent to a reproduced light onto a magnetic recording layer. CONSTITUTION:A magnetic recording layer, i.e., a vertical magnetizing film 12 is formed on a base 11 and the soft magnetic thin film 13 transparent to the reproduced light is formed onto the film 12 by the vapor deposition or sputtering through film coating. A planer magnetization 15 having a pattern corresponding to the magnetizing distribution 14 of the film 12 is produced to the film 13 and a component 17 magnetized vertically from the relation of flow of magnetic flux exists at a part surrounded by a circle shown in broken lines. In irradiating a laser light to the part 16 surrounded by a circle in broken lines at reproduction while being subject to linear polarization 5 by a polarizer, the light is transmitted twice so as to be reciprocated through the film 13 at incidence and reflection and the light is subject to rotation twice by the Farady effect. Moreover, a reflected light 5' is reflected on the surface of the film 12 and subject to the rotation due to the magnetic Kerr effect. Thus, the polarized plane rotating angle theta as a whole is the sum of them above thereby improving the S/N at reproduction.

公开(公告)号：JPS60119649A

公开(公告)日：1985-06-27

申请号：JP22815783

申请日：1983-12-02

Applicant: SONY CORP

Inventor： ASO KOUICHI ,  OCHIAI YOSHITAKA ,  SUGIURA GIICHI

IPC: G11B11/10 ,  G11B11/105

Abstract: PURPOSE:To improve the S/N by forming a soft magnetic thin film made of an amorphous material mainly made of Co onto a magnetic recording layer formed on the base. CONSTITUTION:A magnetic recording layer, i.e., a vertical magnetizing film 12 is formed on a base 11 and the soft magnetic thin film 13 made of the amorphous material mainly made of Co formed by the vapor deposition or sputter is formed. A material having a large Kerr rotating angle thetaK is preferred for the film 13 and a low magnetostriction amorphous alloy including lots of cobalt atoms is preferred. The recording of information is recorded to hatched parts and the magnetization 16 is inverted. A magnetized pattern 17 is produced to the film 13 by the magnetic distribution of the magnetic recording layer 12, the magnetized pattern 17 is produced to the film 13 and the information of the layer 12 is transferred to the film 13. The information is read by forming the laser light to linear polarized light 5, irradiating the light to the film 13, utilizing the magnetic Kerr effect where the polarized plane is rotated by the reflection on the film 13 and detecting its reflecting light 5'.