Noise and cross-talk elimination in recording and reproducing video signals

Apparatus for recording on a magnetic tape signals of varying level extending over a pre-determined frequency band;

• which apparatus comprises modulating means for frequency modulating a carrier with said signals to provide frequency modulated signals, transducer means including first and second magnetic heads alternatively traversing the tape at a steady rate and receiving said frequency modulated signals for recording the latter in successive parallel tracks on the tape, drive means for selectively moving said tape at a first relatively slow tape speed by which said heads are made to scan overlapping areas on said tape to provide said tracks in abutting relation and with the widths of said tracks being less than the widths of said heads, and at a second relatively fast tape speed by which said tracks are spaced apart to provide guard bands therebetween and the widths of the tracks are equal to said widths of the heads, first signal processing means operative on said signals in advance of the frequency modulation of said carrier therewith and including non-linear pre-emphasizing means for providing an amount of emphasis to said signals which is dependent on both the level and frequency of said signals, second signal processing means operative on said signals in advance of the frequency modulation thereof for providing an amount of emphasis to said signals which is dependent on the frequency of said signals, and switching means for selectively making operative said first signal processing means and said second signal processing means when the tape is moved at said first and second tape speeds, respectively.

Apparatus for recording and reproducing video signals in successive parallel tracks on a record medium, comprising:

• transducer means for scanning said successive parallel tracks on the record medium;
• a recording section including modulating means for frequency modulating at least a portion of said video signals on a carrier, record signal processing means operative on at least said portion of the video signals in advance of the frequency modulation of said carrier therewith and including first non-linear pre-emphasizing means for providing a first amount of emphasis to at least said portion of the video signals which is dependent on both the level and frequency of the latter, second non-linear pre-emphasizing means acting on said portion of the video signals following the emphasis of the latter by said first non-linear pre-emphasizing means for providing a second amount of emphasis thereto which is different from said first amount of emphasis and also dependent on both the level and frequency of said signals, and means for applying the resulting frequency modulated signals from said modulating means to said transducer means for recording by the latter in said tracks scanned thereby;
• and
• a reproducing section including demodulating means for frequency demodulating the frequency modulated signals reproduced by said transducer means from the successive parallel tracks on the record medium, and reproduced signal processing means operative on the demodulated signals from said demodulating means and including first non-linear de-emphasizing means for providing an amount of de-emphasis to said demodulated signals which is substantially complementary to said first amount of emphasis and which is dependent on both the level and frequency of said demodulated signals, and second non-linear de-emphasizing means acting on said demodulated signals for providing a second amount of de-emphasis thereby which is substantially complementary to said second amount of emphasis and which is dependent on both the level and frequency of said demodulated signals, said amounts of emphasis and de-emphasis by said first non-linear pre-emphasizing and de-emphasizing means being suitable to substantially eliminate the FM noise signal from said demodulated signals, and said amounts of emphasis and de-emphasis by said second non-linear pre-emphasizing and de-emphasizing means being suitable to substantially eliminate the interfering signal due to cross-talk from said demodulated signal.

Apparatus for recording and reproducing video signals in successive parallel tracks on a magnetic tape signals of varying level extending over a predetermined frequency band;

• said apparatus comprising:
• transducer means including first and second magnetic heads alternatively traversing said tape at a steady rate;
• drive means for selectively moving said tape at a first relatively slow tape speed by which said heads are made to scan overlapping areas on said tape to provide said tracks in abutting relation and with track widths smaller than the widths of said heads, and at a second relatively fast tape speed by which said tracks are spaced apart to provide guard bands therebetween and track widths equal to said head widths;
• a recording section including modulating means for frequency modulating at least a portion of said video signals on a carrier, first record signal processing means operative on at least said portion of the video signals in advance of the frequency modulation of said carrier therewith and including non-linear pre-emphasizing means for providing a first amount of emphasis to at least said portion of the video signals which is dependent on both the level and frequency of the latter, second record signal processing means in said recording section operative on at least said portion of the video signals in advance of the frequency modulation thereof for providing an amount of emphasis thereto which is dependent on the frequency of said portion of the video signals, and means for applying the resulting frequency modulated signals from said modulating means to said transducer means for recording by the latter in said tracks scanned thereby;
• and
• a reproducing section including demodulating means for frequency demodulating the frequency modulated signals reproduced by said transducer means from the successive parallel tracks on the record medium, first reproduced signal processing means operative on the demodulated signals from said demodulating means and including non-linear de-emphasizing means for providing a first amount of de-emphasis to said demodulated signals which is substantially complementary to said first amount of emphasis and which is dependent on both the level and frequency of said demodulated signals, and second reproduced signal processing means operative on said demodulated signals for providing an amount of de-emphasis to said demodulated signals which is substantially complementary to said amount of emphasis provided by said second record signal processing means and which is dependent on the frequency of said demodulated signals, and switching means for selectively making operative the first mentioned record signal processing means and the first mentioned reproduced signal processing means when the tape is moved at a first tape speed and for selectively making operative said second record signal processing means and said second reproduced signal processing means when the tape is moved at said second tape speed.

Apparatus for reproducing video signals which are recorded in successive parallel tracks on a record medium with at least a portion of the video signals, as recorded in said tracks, being non-linearly pre-emphasized with a first amount of emphasis dependent on both the level and frequency of said portion of the video signals and with a second amount of emphasis which is different from the first mentioned amount of emphasis and also dependent on both the level and frequency of said signals, and then being frequency modulated on a carrier;

• said apparatus comprising transducer means for scanning said successive parallel tracks and reproducing the signals recorded therein, demodulating means for frequency demodulating the frequency modulated signals reproduced by said transducer means, and reproduced signal processing means operative on the demodulated signal from said demodulating means and including first non-linear de-emphasizing means for providing a first amount of de-emphasis to said demodulated signals which is substantially complementary to said first amount of emphasis and which is dependent on both the level and frequency of said demodulated signals, and second non-linear de-emphasizing means acting on said demodulated signals for providing a second amount of de-emphasis thereto which is substantially complementary to said second amount of emphasis and which is dependent on both the level and frequency of said demodulated signals, said first amounts of emphasis and de-emphasis being suitable to substantially eliminate the FM noise signal from said demodulated signals, and said second amounts of emphasis and de-emphasis being suitable to substantially eliminate the interfering signal due to cross-talk from said demodulated signals.

Apparatus for reproducing video signals which are recorded in successive parallel tracks on a magnetic tape with at least a portion of the video signals, as recorded in said tracks, being non-linearly pre-emphasized with an amount of emphasis dependent on both the level and frequency of said portion of the video signals and then being frequency modulated on a carrier;

• said apparatus comprising transducer means including first and second magnetic heads alternately traversing said tape at a steady rate for scanning said successive parallel tracks and reproducing the signals recorded therein, demodulating means for frequency demodulating the frequency modulated signals reproduced by said transducer means, drive means for selectively moving said tape at a first relatively slow tape speed by which said heads are made to scan overlapping areas on said tape for reproducing signals recorded in tracks which are in abutting relation and which have track widths smaller than the widths of said heads, and at a second relatively fast tape speed by which said heads are made to scan spaced apart areas for reproducing signals recorded in tracks which are similarly spaced apart to provide guard bands therebetween and track widths equal to said head widths, said portion of the video signals being pre-emphasized with a second amount of emphasis which is smaller than the first mentioned amount of emphasis and dependent only on the frequency of said portion of the video signals when the signals are recorded in said spaced apart tracks, first reproduced signal processing means operative on the demodulated signals from said demodulating means and including non-linear de-emphasizing means for providing an amount of de-emphasis to said demodulated signals which is substantially complementary to the first mentioned amount of emphasis and which is dependent on both the level and frequency of said demodulated signals, second reproduced signal processing means operative on said demodulated signals for providing an amount of de-emphasis to said demodulated signals which is substantially complementary to said second amount of emphasis and which is dependent on the frequency of said demodulated signals, and switching means for selectively making operative the first mentioned reproduced signal processing means when the tape is moved at said first tape and for selectively making operative said second reproduced signal processing means when the tape is moved at said second tape speed.