GB1275307A - Magnetic recording and reproducing system - Google Patents

Abstract

1275307 Recording and playback SONY CORP 12 July 1969 35215/69 Heading G5R In a magnetic recording apparatus which incoporates a means for guiding magnetic tape, first and second recording heads are moved in operation relative to the tape to trace two substantially parallel record tracks on the tape, the second at least partly overlapping the first. First and second input signals are applied to arrangements which respond thereto to provide first and second signals for application to the first and second heads respectively. The arrangement responding to the second input signal operates such that the signal recorded on the second track is of substantially higher or lower frequency than that recorded on the first track, to enable the recordings from the two overlapped tracks to be distinguished on playback. The system is particularly for use in recording luminance and chrominance video signals in separate tracks, whilst economizing on tape. The luminance and chrominance signals are separated by suitable filters from a video input signal, and the luminance signal is frequency modulated on a relatively high carrier frequency (3À3 MHz) before application to its related recording head, while the chrominance signal is beaten with a local oscillator frequency to provide a relatively low frequency signal (1À06 MHz) which is mixed with a pilot signal before application to its head. The head for the luminance signal may be narrower than that for the chrominance, and the head gaps may be angularly displaced from one another at about 30 degrees, that for the luminance signal being set transverse to the tape direction. The video recording system is of the normal type wherein the tape is wrapped helically around a support drum, the heads being rotated to form oblique recording tracks across the tape. The head separation is such that the tracks partly overlap, the luminance signals being recorded partly over the chrominance. The heads could be arranged so that the tracks fully overlap. A playback system must be provided which appropriately demodulates the luminance and chrominance signals.