PURPOSE: To prevent a laser beam deviating from recording tracks by providing with crystalline guide tracks by simply heating in such a manner that the recording plate is made flush with the guide track plane along the recording tracks including an amorphous magnetic film.
CONSTITUTION: An amorphous thin magnetic film 2 is formed on a plastic or plastic disc 1 by using a material, such as Gd, Dy or Fe base, of which the recording temp. is lower than the crystallization temp. and the crystallization causes a change in light transmittance or reflectance. Next, an SiO2 film 3 is formed as a protecting film on the film 2. Then, both side parts along magnetic recording tracks 5 are heated to a temperature above the crystallization temp., for example, about 350°C, by a short wave length (about 4,880) laser beam such as Ar laser beam, whereby guide tracks 4 are formed. Even if recording bits 6 are repeatedly thermomagnetically recorded in the tracks 5 around 100°C of Curie temp. by irradiating the laser beam, the tracks 5 are stably recorded without being crystallized. In addition, the laser light is prevented from deviating from the tracks 5.
DEGUCHI TOSHIHISA
TAKAHASHI AKIRA
