Patent ID: 8532299

Claim:
A method of producing, in a code producing device including at least a microcomputer, a two-dimensional code having a code area in which a plurality of data blocks each consisting of a plurality of cells is mapped, comprising steps of: first arranging, by the microcomputer, first type of data codes, the first type of data codes being coded as codewords and indicating data to be disclosed publicly; adding an end identification code successively from a code string composed of the first type of data codes, the end identification code showing an end of the code string; determining whether or not it is required to map second type of data codes in a code area, the second type of data codes being coded as the codewords and kept in secret; arranging a secret identification code successively from the end identification code when it is determined that it is required to map the second types of data codes, the secret identification code showing that the data codes succeeding the secret identification code are the second type of data codes; second arranging the second type of data codes successively from the secret identification code; arranging filler codes after the second type of data codes such that the code area is filled up with the filler codes when a total amount of the codewords mapped in the code area is less than an amount of codewords allowed to be mapped maximally in the code area, the filler codes showing no data to read; and producing the first type of data codes, the end identification code, the secret identification code, the second type of data codes, and the filler codes, into the cells mapped in the code blocks in the code area of the two-dimensional code such that a general purpose reader, which interprets code produced after the end identification code as filler, will not recognize the second type of data codes.