Portable storage medium and apparatus for processing the same

摘要

A magnetic recording layer is formed on one surface of a card-shaped base plate. A printing layer, for printing visible information such as "matters to be attended", is formed on the magnetic recording layer. A laser recording layer is formed on the other surface of the base plate. A visible image, which can be color-developed by radiation of a laser beam, can be recorded on the laser recording layer. The surface of the recording layer is coated with a transparent protection film, and a predetermined pattern is printed on the protection film. The laser recording layer includes a photothermic conversion material and a thermosensitive recording material. The photothermic conversion material has a major absorption wavelength corresponding to a major wavelength of the laser beam. A visible image can be recorded on the card by means of a laser beam without damaging a predetermined pattern on the protection film. Falsification of the visible image by means of a thermal pen can easily been discovered by checking a defect on the predetermined pattern. Therefore, falsification can be prevented.