PURPOSE: To increase the recording capacity of data and to prevent the generation of forgery by forming at least a part of bars as bars capable of reflecting light with a specific reflecting direction characteristic.
CONSTITUTION: A bar code part 4 is constituted of combining plural bars 5 totally reflecting light and plural bars 6a to 6j consisting of diffraction gratings. The grooves of the diffraction gratings of the bars 6a, 6e, 6j are extended from the upper right to the lower left, the grooves of the bars 6b, 6d, 6i are extended from the upper left to the lower right, the grooves of the bars 6c, 6h are horizontally extended, and the grooves of the bars 6f, 6g are vertically extended. For instance, light reflected by the bar 6a is detected by the photodetecting face parts 8b, 8f arranged mutually symmetrical positions of a photodetecting element 8. Thereby data expressed by the bar code can be obtained by reading out only the patterns simultaneously detected by all the photodetecting face parts 8a to 8h. For instance, another data are obtained at the time of reading out the photodtecting patterns of only the photodetecting face parts 8b, 8f.
HOSHINO SHUICHI