Method of reproduction from magneto-optical recording medium

Claim 1

A method of reproducing signals recorded on a magnetooptic recording medium (1) comprising at least a recording layer formed of a multilayer film consisting of a reproducing layer (3), an intermediate layer (4) and a record hold layer (5), which are coupled magnetically, said method comprising: initializing the reproducing layer by an initializing magnetic field to turn the direction of magnetization of the reproducing layer in an initial direction after recording signals in the record hold layer of the magnetooptic recording medium; irradiating the reproducing layer with a laser beam and applying a reproducing magnetic field to the magneto-optical recording medium to create a portion maintaining the initial state, a portion to which the magnetic domain pattern of the record hold layer is transferred and a portion having the same magnetic polarity as that of the reproducing magnetic field in an area corresponding to the spot of the laser beam by a temperature distribution formed by the laser beam; and converting by magnetooptic effect a magnetic signal recorded in the portion to which the magnetic domain pattern of the record hold layer has been transferred to read the magnetic signal.

Claim 2

A method of reproducing signals recorded on a magnetooptic recording medium comprising at least a recording layer formed of a multilayer film consisting of a reproducing layer, an intermediate layer, and a record hold layer, which are coupled magnetically, said method comprising: turning the direction of magnetization of the reproducing layer for initialization in the direction of an initializing magnetic field H ini meeting inequalities: H ini > H C1 + σ w /2M S1 .h₁ H ini < H C3 - σ w /2M S3 .h₃ by applying the initializing magnetic field H ini to the magnetooptic recording medium; irradiating the reproducing layer with a laser beam to form a first region of a temperature lower than a temperature T m , a second region of a temperature not lower than the temperature T m and lower than a temperature T m' , and a third region of a temperature not lower than the temperature T m ' within the spot of the laser beam with application of a reproducing magnetic field H read to the magnetooptic recording medium; and reproducing the information recorded in the record hold layer from the reproducing layer in an optical signal by magnetooptic effect.

Claim 4

A method of reproducing signals recorded on a magnetooptic recording medium comprising at least a recording layer formed of a multilayer film consisting of a reproducing layer, an auxiliary reproducing layer, an intermediate layer and a record hold layer, which are coupled magnetically, said method comprising: turning the direction of magnetization of the reproducing layer for initialization in the direction of an initializing magnetic field H ini meeting inequalities: H ini > (H C1 , H C2a ) AVG + σ w2b /2(M S1 .h₁ + M S2a .h 2a) = H C1+ H ini > H C3 - σ w2b /2M S3 .h₃ where: (H C1 , H C2a ) AVG = (M S1 .h₁.H C1 + M S2a .h 2a .H C2a )/(M S1 .h₁ + M S2a .h 2a ) H C1 < (H C1 , H C2a ) AVG < H C2a (H C1 , H C2a )AVG > σ w2b /2(M S1 .h₁ + M S2a .h 2a ) by applying the initializing magnetic field H ini to the magnetooptic recording medium storing signals; irradiating the reproducing layer with a laser beam to form a region of a temperature lower than a temperature T n , a region of a temperature not lower than the temperature T n and lower than a temperanture T n' , and a region of a temperature not lower than the temperature T n' within the spot of the laser beam with application of a reproducing magnetic field H read to the magnetooptic recording medium; and reproducing the information recorded in the record hold layer through the reproducing layer in an optical signal by magnetooptic effect.