Reproducing method and reproducing apparatus for magneto-optical recording medium using different radiation patterns

Abstract

External magnetic fields H(x) or reproducing light beams L(x) having different intensity patterns are applied to an identical recording position on a magneto-optical recording medium so that different pieces of information corresponding to the patterns are reproduced from the identical recording position. A function H(x) or L(x) is a password for obtaining the information. Only a person, who knows the function, can access specified information recorded on the magneto-optical recording medium. The function H(x) or L(x) is a function in which the magnetic field intensity or the light intensity is modulated with respect to the recording position x so that magnetic domains may be thinned out to perform reproduction at a specified cycle from continuous magnetic domains in a recording area. Other than the use for the purpose of security, reproduced C/N can be remarkably improved by performing reproduction n times while radiating a reproducing light beam P /P which is power-modulated so that the high power P is applied at every cycle which is not less than n times the recording clock, to a specified magneto-optical recording medium capable of magnetic domain-magnifying reproduction.