Color amplitude correction in plural transducer signal playback systems

Claim 2

In a system for correcting chroma amplitude errors in a signal recovered from a record medium by sequential scan of a plurality of transducers, wherein the signal includes color burst portions and a color amplitude reference signal portion, said system having playback circuitry including means for varying its response to said signal in accordance with an error signal applied thereto, the combination comprising: means providing a first error signal in accordance with a difference of said reference signal portion and a norm, means applying said first error signal to said response varying means in said playback circuitry, means for comparing said burst signal portions as recovered from a given one of said scanning transducers with that of a further transducer to provide a second error signal, and means for applying said second error signal to said response varying means in said playback circuitry.

Claim 3

The invention according to claim 1, in which only a given one of said transducers recovers said reference signal portion, said response varying circuitry includes a plurality of equalizing circuit means, means for applying said first error signal to the one of said equalizing means associated with said given transducer means which recovers said reference signal portion, means for providing said second error signal in accordance with the amplitude difference between a burst portion recovered by said given transducer and a burst portion recovered by a further one of said transducer means, and means for applying said second error signal to the equalizing circuit means for said further transducer.

Claim 4

The invention according to claim 1, including means responsive to said recovered signal for separating said reference signal portions, means for detecting the amplitude of said separated reference signal portion, a source of fixed amplitude signal, and means comparing the output amplitude of said detecting means with said fixed amplitude signal to provide said first error signal.

Claim 5

The invention according to claim 1, including first means responsive to said recovered signal for detecting the amplitude of the color burst portion recovered by a given one of said transducers, further means responsive to said recovered signal for detecting the amplitude of the color burst portion recovered by at least one other of said transducers, comparing means coupled to said first and further detecting Means to provide an output indicative of the amplitude difference between the signals applied thereto, and switching means coupled to said comparing means for providing a selected output to said response varying means.

Claim 6

In combination with a playback system having a plurality of transducing means arranged to scan individual information tracks on a record medium to recover a modulated composite color video signal including a plurality of subperiods, each of said tracks containing sub-periods including synchronizing signal portions and burst signal portions, less than all of said tracking containing a sub-period including a color amplitude reference signal portion, apparatus for correcting color amplitude errors in said recovered signal, comprising: separate means coupled to respective ones of said transducers for controllably modifying a signal characteristic as recovered by its associated transducing means, first switching means receiving an input from each of said signal modifying means to provide a combined output thereof, demodulating means coupled to the output of said first switching means, first circuit means coupled to said demodulating means and responsive to said synchronizing portions of said signal to provide said color amplitude reference signal portion, means coupled to said first circuit means and operative to provide a first output in accordance with the amplitude difference of said color amplitude reference and a norm, second and third circuit means including amplitude detecting means coupled to said demodulating means, said second circuit means providing the burst signal portion of said sub-periods in the given information track containing said color amplitude reference signal portion, said third circuit means providing the burst signal portion of said sub-periods of a further information track, amplitude comparing means coupled to output of said second and third circuit means to provide a difference signal therefrom, and means for selectively applying said difference signal as a control input to said signal modifying means.

Claim 7

In combination with a playback system having a plurality of transducing means arranged to scan individual information tracks on a record medium to recover a modulated composite color video signal including a plurality of subperiods, each of said tracks containing sub-periods including synchronizing signal portions and burst signal portions, less than all of said tracking containing a sub-period including a color amplitude reference signal portion, apparatus for correcting color amplitude errors in said recovered signal, comprising: separate means coupled to respective ones of said transducers for controllably modifying a signal characteristic as recovered by its associated transducing means, first switching means receiving an input from each of said signal modifying means to provide a combined output thereof, demodulating means coupled to the output of said first switching means, first circuit means coupled to said demodulating means and responsive to said synchronizing portions of said signal to provide said color amplitude reference signal portion, means coupled to said first circuit means and operative to provide a first output in accordance with the amplitude difference of said color amplitude reference and a norm, second and third circuit means including amplitude detecting means coupled to said demodulating means, said second circuit means providing the burst signal portion of said sub-periods in the given information track containing said color amplitude reference signal portion, said third circuit means providing the burst signal portion of said sub-periods of a further information track, amplitude comparing means coupled to output of said second and third circuit means to provide a difference signal therefrom, and means for selectively applying said difference signal as a control input to said signal modifying means.