A description is given of an disc device using an optical disc (1) for reproducing data from an optical disc (1) with recording tracks. In this device, a laser beam is cast onto the optical disc (1) by an optical head (3) and a reflection beam is converted into an electric signal, which is then amplified by an amplifier. The amplifier signal or amplified signal is drawn out or filtered by an envelope curve detector. The envelope curve signal is drawn out or filtered in accordance with the amplified signal. The envelope curve signal is added to the amplified signal from the amplifier, and the resulting signal is converted by a binary circuit into a binary signal. <IMAGE>
