Optical storage medium having information of dummy data at leading side or trailing side of user data

摘要

A recording medium has a dummy signal area on at least one side of a recording area, and information is recorded with a dummy signal added to at least one of the leading and trailing sides in the recorded information signal. The user data area remains unaffected by repeated overwriting so that recorded user data is reproduced correctly. In particular, the wave form distortion caused by fluidization of a recording film remains at the dummy signal area and does not affect the user data area, so that the reproduction of the target information (user data) is assured. The recording medium further stores thereon information concerning the pattern of the dummy signal that is used, for example the duty cycle of the dummy signal. The information may be recorded in the control data area of the recording medium.