Differential gain and differential phase compensator circuit of a video signal

Claim 1

A method of processing a video signal having luminance and chrominance signals by using a plurality of rotary transducing heads and a recording tape which is moved longitudinally by a drive mechanism, comprising the steps of: expanding a time axis of said video signal by a factor of N to form a time axis expanded video signal; dividing said time axis expanded video signal into N video channels to form N divided, expanded video signals each having a horizontal blanking period; and inserting first and second pilot signals each having a predetermined frequency and DC voltage level alternately in a predetermined position in successive ones of said horizontal blanking periods, said first pilot signal having a DC voltage level near white peak level and said second pilot signal having a DC voltage level near black level.

Claim 2

A method of processing a video signal having luminance and chrominance signals by using a plurality of rotary transducing heads and a recording tape which is moved longitudinally by a drive mechanism, comprising the steps of: expanding a time axis of said video signal by a factor of N to form a time axis expanded video signal; dividing said time axis expanded video signal into N video channels to form N divided, expanded video signals each having a horizontal blanking period; and inserting first and second pilot signals each having a predetermined frequency and DC voltage level alternately in a predetermined position in successive ones of said horizontal blanking periods, said first pilot signal having a DC voltage level near white peak level and said second pilot signal having a DC voltage level near black level.

Claim 4

An apparatus for processing a video signal having luminance and chrominance signals comprising: means for expanding a time axis of said video signal by a factor of N to form a time axis expanded video signal; means for dividing said time axis expanded video signal into N video channels to form N divided, expanded video signals each having a horizontal blanking period; means for producing first and second pilot signals each having a predetermined frequency and DC voltage level, said DC voltage level of said first pilot signal being different from said DC voltage level of said second pilot signal; and means for adding said first and second pilot signals alternately in successive ones of said horizontal blanking periods.

Claim 5

An apparatus for processing a video signal having luminance and chrominance signals comprising: means for expanding a time axis of said video signal by a factor of N to form a time axis expanded video signal; means for dividing said time axis expanded video signal into N video channels to form N divided, expanded video signals each having a horizontal blanking period; means for producing first and second pilot signals each having a predetermined frequency and DC voltage level, said DC voltage level of said first pilot signal being different from said DC voltage level of said second pilot signal; and means for adding said first and second pilot signals alternately in successive ones of said horizontal blanking periods.

Claim 7

An apparatus for reproducing and processing a video signal having luminance and chrominance signals from a recording tape, said video signal being recorded by a process including a time axis expansion by a factor of N, division into N video channels to form N divided, expanded video signals each having a horizontal blanking period, and insertion of pilot signals, said pilot signals having first and second forms and being alternately inserted in a predetermined position of successive ones of said horizontal blanking periods, said first form of pilot signal having a DC voltage level different from said second form of pilot signal; said apparatus comprising: a plurality of transducing heads for generating N reproduced, divided, expanded video signals from said tape, said reproduced, divided, expanded video signals having a chroma level and a chroma phase and being subject to a time base error; means responsive to said reproduced, divided, expanded video signals for reducing said time base error; means for combining said N reproduced, divided, expanded video signals into one channel video signal having a chroma level and a chroma phase; means for reproducing said two pilot signals; and means responsive to said pilot signals for compensating said chroma level and said chroma phase of said one channel video signal in response to said reproduced pilot signals.

Claim 8

An apparatus for reproducing and processing a video signal having luminance and chrominance signals from a recording tape, said video signal being recorded by a process including a time axis expansion by a factor of N, division into N video channels to form N divided, expanded video signals each having a horizontal blanking period, and insertion of pilot signals, said pilot signals having first and second forms and being alternately inserted in a predetermined position of successive ones of said horizontal blanking periods, said first form of pilot signal having a DC voltage level different from said second form of pilot signal; said apparatus comprising: a plurality of transducing heads for generating N reproduced, divided, expanded video signals from said tape, said reproduced, divided, expanded video signals having a chroma level and a chroma phase and being subject to a time base error; means responsive to said reproduced, divided, expanded video signals for reducing said time base error; means for combining said N reproduced, divided, expanded video signals into one channel video signal having a chroma level and a chroma phase; means for reproducing said two pilot signals; and means responsive to said pilot signals for compensating said chroma level and said chroma phase of said one channel video signal in response to said reproduced pilot signals.

Claim 9

An apparatus for reproducing and processing a video signal having luminance and chrominance signals from a recording tape, said video signal being recorded by a process including a time axis expansion, division into a plurality of video channels to form a plurality of divided, expanded video signals each having a horizontal blanking period, and insertion of pilot signals, said pilot signals having at least two forms and being alternately inserted in a predetermined position of successive ones of said horizontal blanking periods, said two forms of pilot signals respectively having different DC voltage levels; said apparatus comprising: a plurality of transducing heads for generating a plurality of reproduced, divided, expanded video signals from said tape, said reproduced, divided, expanded video signals having a chroma level and a chroma phase and being subject to a time base error; means responsive to said reproduced, divided, expanded video signals for reducing said time base error; means for combining said plurality of reproduced, divided, expanded video signals into one channel video signal having a chroma level and a chroma phase; means for reproducing said two pilot signals; and means responsive to said pilot signals for compensating said chroma level and said chroma phase of said one channel video signal in response to said reproduced pilot in which said chroma level compensating means comprises a detecting circuit for detecting levels of said reproduced pilot signals, a memory circuit responsive to said detecting circuit for memorizing levels of said reproduced pilot signals as detected by said detecting circuit, a comparing circuit responsive to said memory circuit for making comparisons of levels of said reproduced pilot signals as memorized by said memory circuit to a reference level and producing output signals which are based on said comparisons and indicative of level errors of said reproduced pilot signals, a circuit for mixing said output signals to produce a chroma gain compensation signal, and a chroma level controlling circuit controlled by said chroma gain compensation signal to compensate for said level errors.

Claim 10

An apparatus for reproducing and processing a video signal having luminance and chrominance signals from a recording tape, said video signal being recorded by a process including a time axis expansion, division into a plurality of video channels to form a plurality of divided, expanded video signals each having a horizontal blanking period, and insertion of pilot signals, said pilot signals having at least two forms and being alternately inserted in a predetermined position of successive ones of said horizontal blanking periods, said two forms of pilot signals respectively having different DC voltage levels; said apparatus comprising: a plurality of transducing heads for generating a plurality of reproduced, divided, expanded video signals from said tape, said reproduced, divided, expanded video signals having a chroma level and a chroma phase and being subject to a time base error; means responsive to said reproduced, divided, expanded video signals for reducing said time base error; means for combining said plurality of reproduced, divided, expanded video signals into one channel video signal having a chroma level and a chroma phase; means for reproducing said two pilot signals; and means responsive to said pilot signals for compensating said chroma level and said chroma phase of said one channel video signal in response to said reproduced pilot in which said chroma level compensating means comprises a detecting circuit for detecting levels of said reproduced pilot signals, a memory circuit responsive to said detecting circuit for memorizing levels of said reproduced pilot signals as detected by said detecting circuit, a comparing circuit responsive to said memory circuit for making comparisons of levels of said reproduced pilot signals as memorized by said memory circuit to a reference level and producing output signals which are based on said comparisons and indicative of level errors of said reproduced pilot signals, a circuit for mixing said output signals to produce a chroma gain compensation signal, and a chroma level controlling circuit controlled by said chroma gain compensation signal to compensate for said level errors.