Fuji Photo Film Company, Limited

Yoshiki Iwase

Kazuya Oda

Izumi Miyake

Kiyotaka Kaneko

Katsuo Nakadai

Yasuhito Kobayashi

A data signal is modulated by an exclusive-OR operation applied to a carrier signal and a data signal to be recorded. Demodulation is similarly performed by an exclusive-OR operation applied to the carrier signal and signal indicative of read data. This makes it possible to construct the modulating/demodulating circuit in the form of a digital circuit.

Modulating/demodulating circuit for multiplex recording/playback of data

A field/frame conversion circuit for use in a magnetic recording/reproducing apparatus which magnetically records and reproduces still images or the like. In the field/frame conversion circuit, after the frequency of a field signal obtained from a magnetic recording medium such as a magnetic disc and composed of frequency-multiplexed brightness and chroma signals is converted into a higher frequency band than the frequency band of the brightness signal, the field signal is delayed in the frequency modulated state thereof 0.5 horizontal scan period necessary for the field/frame conversion by a signal delay line having a wide band frequency characteristic. The thus delayed field signal and an undelayed field signal are selected alternately at every one vertical scan period by signal switching means so as to perform the field/frame conversion.

Field/frame conversion circuit

DPSK exclusive-OR demodulator

Growing community of inventors

Tokyo, Japan

Yoshiki Iwase