METHOD FOR USING MAGNETIC RECORDING MEDIUM

摘要

A method for using a magnetic recording medium such as a magnetic card which makes it hard to alter recorded information and easy to record information that is hard to alter. Specifically, a method for using a magnetic recording medium having, on at least part of its substrate, an irreversible recording layer containing an irreversible recording material whose saturation magnetization changes irreversibly by heating, wherein an initially heated area, in which a plurality of heated bars, whose saturation magnetization has been irreversibly changed by preheating the irreversible recording layer, are arranged in a bar code-like manner, is formed, and unheated bars, each extending between the heated bars, are heated to change the arrangement pattern of the heated bars, whereby information is recorded.