JPS6414768A - Copyright information detector - Google Patents

Abstract

PURPOSE:To prevent the generation of a malfunction in a music signal reducing energy in a specific frequency band by adding a false irregular noise to obtain copyright information. CONSTITUTION:The titled device is provided with a computing means 2 for finding out mutual correlation between a false irregular noise having a fixed period and a signal reproduced from a recording medium and a deciding means 3 for deciding the addition of the same false irregular noise as that of the reproduced signal based on the mutual correlation found out by the means 2. Namely, a mutual correlation computing means 203 finds out the mutual correlation between music information inputted to an input 2031 and an output signal outputted from an M-sequence generator 202 and inputted to an input 2032 and transfers a mutual correlation function to a deciding means 3. The deciding means 3 decides whether a false irregular noise is included in a reproduced signal or not based on the type of the mutual correlation function. Consequently, the generation of the malfunction in a music signal reducing energy in a specific frequency band can be prevented.