Video signal translating circuit

Claim 2

A signal translating stage for video signals comprising, in combination: a phase splitter, having an input responsive to said video signals and a pair of resistive load impedances, for developing oppositely phased versions of said video signals across respective ones of said pair of resistive load impedances; an output terminal for said signal translating stage; means, including a first reactive impedance, for coupling signals developed across one of said load impedances to said output terminal; means, including a second reactive impedance, opposite in reactance sign to said first reactive impedance, for coupling signals developed across the other of said load impedances to said output terminal; wherein the parameters of said reactive impedances are selected to cause said signal translating stage to exhibit a non-linear delay-versus-frequency characteristic having a desired shape over the range of fequencies occupied by said video signals; and means for varying the amplitude-versus-frequency response characteristic of said signal translating stage without substantial disturbance of the shape of the delay-versus-frequency characteristic thereof, said last-named means comprising means for varying the value of said one resistive load impedance.

Claim 3

Apparatus in accordance with claim 1 wherein said first reactive impedance comprises a capacitor, wherein said second reactive impedance comprises an inductor, and wherein said delay-versus-frequency characteristic exhibits a delay maximum in an intermediate portion of said range of frequencies.

Claim 4

Apparatus in accordance with claim 2 wherein said second-named coupling means includes a resistor in parallel with said inductor.

Claim 5

Apparatus in accordance with claim 2 wherein said first-named coupling means includes a resistor in series with said capacitor.

Claim 6

In a color television receiver wherein the detected output of an intermediate frequency amplifier comprises a composite color video signal inclusive of a luminance signal component subject to delay distortion as a consequence of the non-linear delay-versus-frequency characteristic of said intermediate frequency amplifier; a luminance signal processing channel comprising a video signal translating stage including, in combination: a transistor having base, emitter, and collector electrodes; means for coupling signals inclusive of said luminance signal component to said base electrode; a first load resistor coupled to said collector electrode; a second load resistor coupled to said emitter electrode; a video signal translating stage output terminal; means comprising a first frequency dependent impedance subject to impedance variations with frequency of a first sense, for coupling signals developed across said first load resistor to said output terminal; means, comprising a second frequency dependent impedance subject to impedance variations with frequency of a second sense opposite to said first sense, for coupling signals developed across said second load resistor to said output terminal; and a peaking control for said luminance signal processing channel comprising means for varying the amplitude-versus-frequency response characteristic of said video signal translating stage, over a range inclusive of (a) a response characteristic exhibiting an appreciably higher amplitude response to high frequency luminance signal components than to low frequency luminance signal components and (b) a response characteristic exhibiting substantially equal amplitude response to high and low frequency luminance signal components, while substantially maintaining a non-linear delay-versus-frequency characteristic for said video signal translating stage of a shape providing substantial compensation for said delay distortion; said last-named means comprising means for varying the resistance value of one of said load resistors.

Claim 7

In a color television receiver wherein the detected output of an intermediate frequency amplifier comprises a composite color video signal inclusive of a luminance signal component subject to delay distortion as a consequence of the non-linear delay-versus-frequency characteristic of said intermediate frequency amplifier; a luminance signal processing channel comprising a video signal translating stage including, in combination: a transistor having base, emitter, and collector electrodes; means for coupling signals inclusive of said luminance signal component to said base electrode; a first load resistor coupled to said collector electrode; a second load resistor coupled to said emitter electrode; a video signal translating stage output terminal; means comprising a first frequency dependent impedance subject to impedance variations with frequency of a first sense, for coupling signals developed across said first load resistor to said output terminal; means, comprising a second frequency dependent impedance subject to impedance variations with frequency of a second sense opposite to said first sense, for coupling signals developed across said second load resistor to said output terminal; and a peaking control for said luminance signal processing channel comprising means for varying the amplitude-versus-frequency response characteristic of said video signal translating stage, over a range inclusive of (a) a response characteristic exhibiting an appreciably higher amplitude response to high frequency luminance signal components than to low frequency luminance signal components and (b) a response characteristic exhibiting substantially equal amplitude response to high and low frequency luminance signal components, while substantially maintaining a non-linear delay-versus-frequency characteristic for said video signal translating stage of a shape providing substantial compensation for said delay distortion; said last-named means comprising means for varying the resistance value of one of said load resistors.

Claim 8

Apparatus in accordance with claim 5 wherein said first frequency dependent impedance comprises a capacitor, wherein said second frequency dependent impedance comprises the parallel combination of an inductor and a resistor, wherein said one load resistor is said first load resistor, and wherein the parameter values for said video signal translating stage are such that said delay-versus-frequency characteristic of said video signal translating stage exhibits a delay maximum in an intermediate portion of the range of frequencies occupied by said luminance signal component.

Claim 9

Apparatus in accordance with claim 6 wherein said first frequency dependent impedance comprises the series combination of a capacitor and a resistor, wherein said second frequency dependent impedance comprises an inductor, and wherein said one load resistor is said first load resistor.

Claim 10

In a television receiver wherein the detected output of an intermediate frequency amplifier comprises video signals subject to delay distortion as a consequence of the non-linear delay-versus-frequency characteristic of said intermediate frequency amplifier, a video signal translating stage providing both compensation of said delay distortion and adjustable peaking of said video signals; said video signal translating stage comprising: a transistor having base, emitter and collector electrodes; means for coupling said video signals to said base electrode; a first load resistor coupled to said collector electrode; a second load resistor coupled to said emitter electrode; a video signal translating stage output terminal; a capacitor coupled between said collector electrode and said output terminal; an inductor shunted by a resistor to form a parallel combination, said parallel combination being coupled between said emitter electrode and said output terminal; wherein the values of said capacitor and the inductor and resistor of said parallel combination are such as to provide said video signal translating stage with a non-linear delay-versus-frequency characteristic exhibiting a delay maximum in an intermediate portion of the range of frequencies occupied by said video signals and providing substantial compensation for the delay distortion introduced by said intermediate frequency amplifier; and wherein said first load resistor comprises a variable resistor providing a facility for varying the amplitude-versus-frequency response characteristic of said video signal translating stage while maintaining the effect of said delay distortion compensation.

Claim 11

In a television receiver wherein the detected output of an intermediate frequency amplifier comprises video signals subject to delay distortion as a consequence of the non-linear delay-versus-frequency characteristic of said intermediate frequency amplifier, a video signal translating stage providing both compensation of said delay distortion and adjustable peaking of said video signals; said video signal translating stage comprising: a transistor having base, emitter and collector electrodes; means for coupling said video signals to said base electrode; a first load resistor coupled to said collector electrode; a second load resistor coupled to said emitter electrode; a video signal translating stage output terminal; a capacitor coupled between said collector electrode and said output terminal; an inductor shunted by a resistor to form a parallel combination, said parallel combination being coupled between said emitter electrode and said output terminal; wherein the values of said capacitor and the inductor and resistor of said parallel combination are such as to provide said video signal translating stage with a non-linear delay-versus-frequency characteristic exhibiting a delay maximum in an intermediate portion of the range of frequencies occupied by said video signals and providing substantial compensation for the delay distortion introduced by said intermediate frequency amplifier; and wherein said first load resistor comprises a variable resistor providing a facility for varying the amplitude-versus-frequency response characteristic of said video signal translating stage while maintaining the effect of said delay distortion compensation.