Bar code system using segments having different reflective directivities.

摘要

A bar code system for representing prescribed data with a combination of a geometrical arrangement of a plurality of segments such as code bars, and, additionally, a prescribed reflective directivity of each of the segments by such means as diffraction grating, hologram or a multiplicity of parallel grooves. This combination allows the amount of data that can be stored to be increased and discourages any attempt to make an unauthorized duplication of the bar code system. This bar code system may be used as means for preventing forgery or tampering of information storage cards such as magnetic cards and IC cards.