Optically readable compact disc in credit card format - carries twenty megabytes of data on five cm diameter disc

摘要

The disc holder (1) has standard credit card dimensions, i.e. 55 mm (a) by 85 mm (b), but its thickness (d) depends on the thickness of the optical compact disc (2). The aperture for the disc is surrounded by a circular groove (3), which passes through most of the thickness of the holder. The material between the groove and the central aperture forms a flexible retainer for the disc. The disc is produced by standard Compact Disc techniques. The holder is made from material which is slightly flexible, but is rigid enough to protrect the disc from too much bending. @(6pp Dwg.No.1/3)@.