| 摘要 |
PROBLEM TO BE SOLVED: To provide an optical code that has a recording density higher than a monochrome optical code while retaining compatibility with a standard conventional monochrome optical code.SOLUTION: Colors are assigned to modules for an optical code so as to be distinguished from one of reference colors of two or more of types. The reference colors of two or more types are composed of a plurality of bright reference colors equal to or higher than a predetermined bright color threshold in reflectance or brightness, and a plurality of dark reference colors equal to or lower than a predetermined dark color threshold in reflectance or brightness. One of the bright reference colors is assigned to a module distinguished as a bright color, such that the module can be distinguished. One of the dark reference colors is assigned to a module distinguished as a dark color, such that the module can be distinguished. Thereby, two types of data are recorded, one of which is general-purpose data recorded according to information indicating which one of a bright reference color and dark reference color each module has, and the other of which is exclusive data recorded according to information indicating which type of the bright reference color or dark reference color each module has. |
