Method of and apparatus for writing and reading a magneto-optica

Details Method of and apparatus for writing and reading a magneto-optica Method of and apparatus for writing and reading a magneto-optica

1989-12-20

1991-11-12

Fuller, Benjamin R.

Dynamic information storage or retrieval

Storage or retrieval by simultaneous application of diverse...

Magnetic field and light beam

369100, 369110, 369116, 360 59, 360 66, 360114, 346 744, G11B 1100

Patent

active

050653776

ABSTRACT:
A method and apparatus for optically writing and reading information as a pattern of magnetic domains in the information recording layer of a record carrier. An optical scanning beam is focused to a diffraction-limited radiation spot for scanning the recording layer, and the region under the spot is subjected to a magnetic field generated by a magnetizing coil energized with a square-wave energizing current having a duty cycle which is modulated in accordance with the information signal. The frequency and amplitude of the energizing current are independent of the information signal, and the frequency thereof exceeds the optical cut-off frequency determined by the size of the radiation spot. Several different values of the information signal can therefore be recorded within a distance equal to the width of the radiation spot in the scanning direction at each position thereof, so that the recorded information density exceeds that corresponding the width of the scanning spot. Read-out is based on the "grey" level produced by the recorded information areas under the scanning spot at each position thereof, so that the same size scanning spot can be used for both writing and reading the record carrier.

REFERENCES:
patent: 3582570 (1971-06-01), Cushner et al.
patent: 3626114 (1971-12-01), Lewicki et al.
patent: 3736385 (1973-05-01), Waring, Jr.
patent: 4466004 (1984-08-01), Kobayashi et al.
patent: 4922454 (1990-05-01), Taki

Affiliated with

Also associated with

Rating

Method of and apparatus for writing and reading a magneto-optica does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Method of and apparatus for writing and reading a magneto-optica, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Method of and apparatus for writing and reading a magneto-optica will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-1017867