Magneto-optical recording medium having a transfer control layer

Abstract

A magneto-optical recording medium, including a recording layer, a transfer control layer magnetically coupled to the recording layer, and a reproduction layer. The recording layer includes a recording magnetic domain in which information is recorded by a magnetization direction vertical to the surface of the film. The reproduction layer includes a reproduction magnetic domain in which information in the recording layer is transferred and formed as a magnetization direction by magnetic coupling. The direction of magnetization of the recording magnetic domain of the recording layer and the direction of magnetization of the transfer control layer corresponding to the recording magnetic domain are in opposite directions in at least part of the range of temperatures less than a transfer temperature where the reproduction magnetic domain is transferred to the reproduction layer. The Curie point temperature of the transfer control layer is higher than this transfer temperature.

1 . A method of reproducing a magneto-optical recording medium of reproducing information by transferring a recording magnetic domain recorded on a recording layer to a reproduction layer, the magneto-optical recording medium comprising: 
 the recording layer having a recording magnetic domain in which information is recorded according to a magnetization direction vertical to a surface of a film;    a transfer control layer magnetically coupled to the recording layer; and    the reproduction layer to which information recorded in the recording layer is transferred to form a reproduction magnetic domain of the magnetization direction vertical to the surface of the film,    the method including:    a reproduction step of detecting the information by transferring the recording magnetic domain from the recording layer to the reproduction layer only in a temperature range in which information can be transferred from the recording layer wherein    during reproduction, the rotation of polarized plane of the light beam reflected by the reproduction layer and the rotation of polarized plane of the light beam reflected by the recording layer by being transmitted by the reproduction layer are caused to compensate and cancel each other in a low temperature range below the temperature at which the reproduction magnetic domain is transferred to the reproduction layer within a light spot on the magneto-optical recording medium heated by the irradiating laser beam.    
   
   
       2 . An apparatus of reproducing a magneto-optical recording medium to reproduce information by transferring a recording magnetic domain from a recording layer to a reproduction layer only in a temperature range in which information can be transferred from the recording layer and detecting the information, 
 the apparatus comprising:    means of irradiating the magneto-optical recording medium with a laser beam during reproduction, and heating means of raising the temperature of the magneto-optical recording medium so that part of the light spot of the irradiating laser beam includes a temperature range in which the reproduction magnetic domain of the reproduction layer is stable, wherein    the information is detected by transferring the recording magnetic domain from the recording layer to the reproduction layer only in a temperature range in which information can be transferred from the recording layer by the magnetic coupling force between the recording layer and the reproduction layer within the light spot.