Apparatus for recording and reproducing a plurality of television signals of different systems

Claim 1

A video signal recording and reproducing apparatus in which video signals of a plurality of television systems in which the numbers of scanning lines per frame are different are recorded or reproduced onto/from a magnetic tape (102) by an oblique scanning method by using magnetic heads (103, 104) attached to a rotary drum (101), comprising: (a) an A/D converter (11) for converting input video signals into digital signals; (b) a buffer memory (16) for temporarily storing the digital signals which were output from the A/D converter (11); (c) means (9) for discriminating the television system of the input video signal or an input terminal (10) of a discrimination signal indicative of the tele­vision system of the input video signal; (d) an address control circuit (17) for deciding a start point and an end point of effective lines to be recorded onto the magnetic tape (102) in accordance with the discrimination signal of the television system when the digital signal which was output from the A/D converter (11) is written into or read out from the buffer memory (16) and for controlling addresses in the buffer memory (16); (e) a D/A converter (18) for converting the digital signal which was read out of the buffer memory (16) into the analog signal; (f) a control signal producing circuit (208) for supplying clocks of a predetermined frequency to the A/D converter (11), buffer memory (16), address control circuit (17), and D/A converter (18), respectively, in accordance with the discrimination signal indicative of the television system of the input video signal; (g) a frequency modulating circuit (19) for frequency modulating the analog output signal of the D/A converter (18) so that a frequency modulated signal has a predetermined frequency allocation in accordance with the television system discrimination signal; and (h) a recording amplifier (20) for amplifying an output of the frequency modulating circuit (19) until a predetermined level, wherein an output signal of the recording amplifier (20) is supplied to the magnetic heads (103, 104), and the number of effective lines per frame which are recorded onto the magnetic tape (102) is set to a predetermined value irrespective of the system of the input video signal.