| 摘要 |
PROBLEM TO BE SOLVED: To provide the information recording medium in which a portion of the medium is chemically dissolved, the signal portions are exposed, the information is made as physically projected and recessed shapes so as to make it impossible to produce a copy of the information in its entirety and to provide the information reproducing device. SOLUTION: A step 6A, in which the thickness of a portion of a laminated construction body is stepwise changed, or a pitch 7, in which the thickness of a portion of the body is gradually varied, is provided. Thus, in the process of making an unauthorized copy, the dissolving is made uneven so that the unauthorized physical copy of the data of an optical recording medium by a dissolving is practically impossible. Moreover, the information reproducing device is constituted so that information is read from the portion, in which the thickness is different, and processed to read ciphered information and to identify a genuine product from forgery products. |
