IT1237216B - Overwritable magneto-optical data carrier
- Google Patents
Overwritable magneto-optical data carrier
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Publication number
IT1237216B
IT1237216BIT04848289AIT4848289AIT1237216BIT 1237216 BIT1237216 BIT 1237216BIT 04848289 AIT04848289 AIT 04848289AIT 4848289 AIT4848289 AIT 4848289AIT 1237216 BIT1237216 BIT 1237216B
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Application filed by Nikon CorpfiledCriticalNikon Corp
Priority to IT04848289ApriorityCriticalpatent/IT1237216B/en
Publication of IT8948482A0publicationCriticalpatent/IT8948482A0/en
Application grantedgrantedCritical
Publication of IT1237216BpublicationCriticalpatent/IT1237216B/en
The data carrier has a substrate with a magnetic layer comprising two layers with perpendicular magnetic anisotropy. The upwards direction w.r.t. the carrier is called the 'A-direction' and the downwards direction is called the 'not-A-direction". An initial field is used to magnetise only the second layer immediately before recording and in the A-direction. A premagnetising field in the not-A-direction is used to reverse the magnetisation of the second layer on irradiation with a strong laser beam. Under the influence of the not-A-direction magnetisation of the second layer a bit is formed in the first layer using either not-A or A magnetisation. On irradiation with a weak laser beam and under the influence of the A magnetisation of the second layer, a bit with A or not-A magnetisation is formed in the first layer.
IT04848289A1989-10-251989-10-25Overwritable magneto-optical data carrier
IT1237216B
(en)
Magneto-optical recording method using a magneto-optical recording medium having two or more magnetic layers to allow recording and reproduction to be effected simultaneously and magneto-optical recording medium used in the method