Optical recording apparatus having improved erasing capability

Claim 1

An optical recording apparatus for recording information on a magneto-optical recording medium having an original magnetization by applying a light beam to raise the temperature of the recording medium to approximately the Curie temperature in the presence of a DC bias magnetic field and causing inversion of magnetization in a portion of the recording medium at which the light beam is applied, and for erasing the recording medium by applying a light beam to raise the temperature of the recording medium to approximately the Curie temperature in the presence of a DC bias magnetic field and returning the magnetization in said portion to the original magnetization, wherein the threshold energy for erasure is the same as the threshold energy for recording, wherein said apparatus comprises: a light source for emitting a light beam; means for projecting the light beam emitted by said light source onto the magneto-optical recording medium as a beam spot; means for scanning the recording medium with the beam spot; and means for changing the power of the light beam emitted by said light source in such a manner that the amount of peak energy given to the recording medium by the light beam at the time of erasure is larger than that at the time of recording, so that the width of the beam spot, defined by said threshold energy, is larger at the time of erasure than at the time of recording.