METHOD FOR READING INFORMATION FROM PUNCHED CARRIER AND DEVICE FOR EFFECTING SAME

摘要

METHOD FOR READING INFORMATION FROM PUNCHED CARRIER AND DEVICE FOR EFFECTING SAME A method for reading information from a punched carrier, according to which a radiation flux emitted by a radiation source is modulated by information holes of the punched carrier and then additionally modulated by an additional modulation means, whereupon the double-modulated radiation flux is reflected by a reflector to a photosensitive input of a main converter which converts the radiation flux into a primary information signal. The primary information signal is then compared to a reference signal which changes according to the law of additional modulation, whereupon the preset signal is discriminated. The proposed device for carrying out the foregoing method of reading information from a punched carrier having synchronization and information holes comprises a radiation source optically connected to a reflector through the information holes of the punched carrier, as well as through an additional modulation means. The latter provides for additional modulation of the radiation flux modulated by the information holes of the punched carrier and at the same time can perform the functions of the reflector. The device further includes at least one information channel having a main converter whose output is connected via a main amplifier unit to a synchronizing input of a comparator. The latter comprises a recognition circuit and a preset information signal discrimination circuit; the two circuits are placed in series. The photosensitive element of the main converter is optically connected to the reflector. The main converter converts the radiation flux into primary information signals which are sent to the comparator. The latter compares the primary information signals with a reference signal applied thereto from a reference signal source and changing according to the law of additional modulation.