Apparatus for information recording and reproducing.

摘要

The invention concerns to a method and an apparatus for recording and reproducing information, which are carried out by using a recording medium made of a metal or alloy having phases different in their crystalline structures at at least two temperature regions in the solid state and capable of causing phase transformation by heating and quenching. Information such as signals, letters, patterns and symbols are recorded in a distinctive manner and erased by making use of a change in the spectral reflectance owing to the phase transformation. Rewriting can be made easily by making use of the nergy of a light beam such as a laser beam.