DE4039841A119910620DE4039841DE403984119901213JP3214268919891213AJP19890321426DE403984119910620A120060101AFI20051220RMJPG11B50220060101ALI20051008RMEPG11B201020060101ALI20051008RMEPH04N578220060101ALI20051008RMEPH04N980220060101ALI20051008RMEPH04N9835G11B 2010LI20130101EPBHH04N 9835FI20130101EPBHH04N 578213LI20130101EPBHH04N 9802LI20130101EPBHMagnetic recording method using QPSK modulation operation - superimposing processed digital audio signal onto analogue componentsMAGNETISCHE AUFZEICHNUNGS- UND WIEDERGABEVORRICHTUNGDE2510590C219870423DE2938937A119800410EP0277000A219880803JPH01105301A19890421JP 01303602 A mit AbstractF. Winkel, Technik der Magnetspeicher, Springer Verlag Berlin Göttingen Heidelberg 1960, S. 404-412Ch. Scholz, Magnettontechnik, Franzis-Verlag München, 1969, S. 123,124Abstract & JP 60195704 AFunkschau 20, Sept. 1987, S. 35-37HITACHI LTDJPHITACHI, LTD., TOKIO/TOKYO, JPAMADA NOBUTAKAJPTAKEUCHI TOSHIFUMIJPABETA AKIRAJPARAI TAKAOJPUSUDA KOUEIJPAMADA, NOBUTAKATAKEUCHI, TOSHIFUMIABETA, AKIRAARAI, TAKAO, YOKOHAMA, JPUSUDA, KOUEI, IBARAKI, JPA video input (10) is processed (11) and fed to the heads (52b) of a rotating drum. Digital audio signals are received by a digital processor (31) executing a formatting operation that involves the addition of a synchronising signal and error correction code. The processor output is modulated (32) by a unit which receives the output of a carrier oscillator (40) and a 90 deg. phase shifted (41) version of the signal. The modulated output is summed together with the frequency modulated (21a, 21b) versions of the analogue audio signals. These are fed to a second head (52). ADVANTAGE - Avoids cross modulation of digital audio and bias signals on f.m. audio and video signals. Ensures reproduction of output level of digital audio signal.