| 摘要 |
PURPOSE: To attain the recording and reproducing of high-speed data by specifying the respective contents of a once-writing-amorphous thin-film optical recording element made of an alloy consisting of a ternary compsn. composed of Sb, Al and Sn. CONSTITUTION: The once-writing-amorphous thin-film optical recording element made of the alloy having the compsn. of a polygonal shape, for example, ABCDE in the ternary compsn. diagram composed of the Sb, Al and Sn and expressed by formula I is so formed as to have the per cent coordinates of formula II with respect to the vertex of the polygonal shape ABCDE. As a result, the execution of high-density recording at a high speed is made possible. The recording is executed by rotating the optical recording element 16 at a specified speed to have information tracks 30 recorded from the outer side to the inner side on the element 16 in the form of selected crystallized regions. In reading out, on the other hand, the element 16 is of a reflection type and radiations are reflected through a lens 26 having the aperture diameter of a high numerical value by interaction with the information marks on the element 16. Electrical reproducible signals are thus formed according to the time change of the radiation illuminance of the reflected laser radiations. |
