Patent attributes
A signal recorded in a work area is read for a predetermined time, the signal is assumed to be a candidate signal, and this signal is stored in a memory. A signal differing from the candidate signal is read for a predetermined time, the signal is assumed to be a comparison signal, and the signal is stored in another memory. A data comparison circuit determines whether or not the candidate signal and the comparison signal are signals with identical content are the same. When it is determined that the contents, the candidate signal is stored in a database area. A signal which is determined to have the same content as that of the candidate signal stored in the database area is deleted in such a manner that the signal can be recovered from the work area. A signal with identical content can easily be detected, and deletion of content recorded in a duplicate manner makes it possible to efficiently use a recording device.
