Magneto-optic memory device for overwriting information on magneto-optic recording medium by using a pair of light spots without using an external magnetic field

U.S. Patent Number: 5357493

Abstract: In a magneto-optic memory device for recording information on a magneto-optic recording medium having a magneto-optic recording film irradiated by a first small diameter light spot and a second larger diameter light spot which is substantially concentric with the first light spot, the temperature of a portion of the recording film around a recording position is changed by the irradiation of the second light spot in accordance with an information signal to be recorded, between a temperature, which is lower than a compensation temperature of the recording film and produces spontaneous magnetization of the recording film having intensity necessary for recording information, and a temperature which is higher than the compensation temperature of the recording film and produces spontaneous magnetization of the recording film having intensity necessary for recording information, and the intensity of the first light spot is increased to raise the temperature of the recording position of the recording film so as to reach near the Curie temperature of the recording film, thereby erasing old information and recording new information at the same time.

Inventors: Okazaki; Yukinori (Osaka, JP), Kobukata; Mieko (Osaka, JP)

Assignee: Matsushita Electric Industrial Co., Ltd. (Osaka, JP)

Application Number: 07/933,771

Issued: 1994-10-18

Expired: 2006-10-18

Classes: 369/13.24 ; 360/59

Field of search: 369/13,110,14 360/59,114 365/122

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