Misconvergence compensating device for color cathode ray tubes

Claim 2

In the combination of a color cathode ray tube including a color screen having arrays of different color phosphors, beam selecting means provided with passages corresponding to said arrays of color phosphors, plural-beam generating means for directing a plurality of electron beams in a common plane toward said screen for impingement on respective phosphors of said arrays through the correspondiNg passages, and deflecting means for causing said plurality of electron beams to scan said screen and including a source of deflection voltage and a pair of deflection coil means connected in parallel to each other and to said source of deflection voltage for producing a nonuniform magnetic scanning field; the improvement comprising a misconvergence compensating device including impedance means connected in series between at least one of said pair of deflection coil means and said source of deflection voltage, the magnitude of the impedance of said impedance means being selectively adjustable to vary the amount of current from said source of deflection voltage flowing in said one deflection coil means relative to the other deflection coil means for controlling said magnetic field produced thereby.

Claim 3

The combination according to claim 1 wherein said variable impedance means includes first and second variable impedance elements respectively connected in series to said one deflection coil means and to the other of said pair of deflection coil means.

Claim 4

The combination according to claim 2, wherein said first and second variable impedance elements are controlled at the same time.

Claim 5

The combination according to claim 1, wherein rectifier means and variable resistance means are connected between said pair of deflection coil means.

Claim 6

In the combination of a color cathode ray tube including a color screen having arrays of different color phosphors, beam selecting means provided with passages corresponding to said arrays of color phsophors, plural-beam generating means for directing a plurality of electron beams in a common plane toward said screen for impingement on respective phosphors of said arrays through the corresponding passages, and deflecting means for causing said plurality of electron beams to scan said screen and including a source of deflection voltage and a pair of deflection coil means connected in parallel to each other and to said source of deflection voltage for producing a nonuniform magnetic scanning field; the improvement comprising a misconvergence compensating device including impedance means connected in series between at least one of said pair of deflection coil means and said source of deflection voltage, the magnitude of the impedance of said impedance means being selectively adjustable to vary the amount of current from said source of deflection voltage flowing in said one deflection coil means relative to the other deflection coil means for controlling said magnetic field produced thereby, and rectifier means and variable resistance means connected between said pair of deflection coil means, wherein said rectifier means includes a first rectifier connected to one of said pair of deflection coil means and a second rectifier connected to the other of said pair of deflection coil means, and said variable resistance means is interposed between said first and second rectifiers.

Claim 7

In the combination of a color cathode ray tube including a color screen having arrays of different color phosphors, beam selecting means provided with passages corresponding to said arrays of color phsophors, plural-beam generating means for directing a plurality of electron beams in a common plane toward said screen for impingement on respective phosphors of said arrays through the corresponding passages, and deflecting means for causing said plurality of electron beams to scan said screen and including a source of deflection voltage and a pair of deflection coil means connected in parallel to each other and to said source of deflection voltage for producing a nonuniform magnetic scanning field; the improvement comprising a misconvergence compensating device including impedance means connected in series between at least one of said pair of deflection coil means and said source of deflection voltage, the magnitude of the impedance of said impedance means being selectively adjustable to vary the amount of current from said source of deflection voltage flowing in said one deflection coil means relative to the other deflection coil means for controlling said magnetic field produced thereby, and rectifier means and variable resistance means connected between said pair of deflection coil means, wherein said rectifier means includes a first rectifier connected to one of said pair of deflection coil means and a second rectifier connected to the other of said pair of deflection coil means, and said variable resistance means is interposed between said first and second rectifiers.

Claim 8

The combination according to claim 1, wherein said pair of deflection coil means are horizontal deflection coil means for producing a pin-cushion-shaped magnetic field.

Claim 9

The combination according to claim 1, wherein said variable impedance means is constituted by variable inductance means.

Claim 10

The combination according to claim 1, wherein said pair of deflection coil means are vertical deflection coil means for producing a barrel-shaped magnetic field.

Claim 11

The combination according to claim 8, wherein said variable impedance means connected to said vertical deflection coil means is constituted by variable resistance means.

Claim 12

In the combination of a color cathode ray tube including a color screen having arrays of different color phosphors, beam selecting means provided with passages corresponding to said arrays of color phosphors, plural-beam generating means arranged in line for directing a plurality of electron beams in a common plane toward the screen for impingement on respective phosphors of the arrays through the corresponding passages, and deflecting Means for causing the plurality of electron beams to scan the screen and including first and second sources of deflection voltage and at least a first and a second pair of deflection coils, the deflection coils of the first pair being connected in parallel to each other and to the first source of deflection voltage for producing a pincushioned-shaped magnetic scanning field, the deflection coils of the second pair being connected in parallel to each other and to the second source of deflection voltage for producing a barrel-shaped magnetic scanning field, the improvement comprising cross-misconvergence compensating means including first impedance means connected in series between at least one of the deflection coils of the first pair and the first source of deflection voltage, the magnitude of the impedance of the first impedance means being selectively adjustable to vary the amount of current from the first source of deflection voltage flowing in the one deflection coil relative to the other deflection coil of the first pair for compensating for cross-misconvergence of the electron beams due to the pincushion shaped magnetic field produced in the first pair of deflection coils and neck twist compensating means including first and second rectifiers and first variable resistance means, the first rectifier being connected to one of the first pair of deflection coils, the second rectifier being connected to the other of the first pair of deflection coils, and the first variable resistance means being connected in series between terminals of like polarity at the first and the second rectifiers and further connected to the first source of deflection voltage for supplying a net rectified current of a predetermined polarity to the first pair of deflection coils.

Claim 13

In the combination of a color cathode ray tube including a color screen having arrays of different color phosphors, beam selecting means provided with passages corresponding to said arrays of color phosphors, plural-beam generating means arranged in line for directing a plurality of electron beams in a common plane toward the screen for impingement on respective phosphors of the arrays through the corresponding passages, and deflecting Means for causing the plurality of electron beams to scan the screen and including first and second sources of deflection voltage and at least a first and a second pair of deflection coils, the deflection coils of the first pair being connected in parallel to each other and to the first source of deflection voltage for producing a pincushioned-shaped magnetic scanning field, the deflection coils of the second pair being connected in parallel to each other and to the second source of deflection voltage for producing a barrel-shaped magnetic scanning field, the improvement comprising cross-misconvergence compensating means including first impedance means connected in series between at least one of the deflection coils of the first pair and the first source of deflection voltage, the magnitude of the impedance of the first impedance means being selectively adjustable to vary the amount of current from the first source of deflection voltage flowing in the one deflection coil relative to the other deflection coil of the first pair for compensating for cross-misconvergence of the electron beams due to the pincushion shaped magnetic field produced in the first pair of deflection coils and neck twist compensating means including first and second rectifiers and first variable resistance means, the first rectifier being connected to one of the first pair of deflection coils, the second rectifier being connected to the other of the first pair of deflection coils, and the first variable resistance means being connected in series between terminals of like polarity at the first and the second rectifiers and further connected to the first source of deflection voltage for supplying a net rectified current of a predetermined polarity to the first pair of deflection coils.

Claim 14

The combination recited in claim 10 further comprising tilt-misconvergence compensating means including second impedance means connected in series between at least one of the deflection coils of the second pair of deflection coils and the second source of deflection voltage, the magnitude of the impedance of the second impedance means being selectively adjustable to vary the amount of current from the second source flowing in the one deflection coil of the second pair and wherein the neck twist compensating means further includes third and fourth rectifiers and second variable resistance means, the third rectifier being connected to one of the second pair of deflection coils, the second rectifier being connected to the other of the second pair of deflection coils, and the second variable resistance means being connected in series between terminals of like polarity at the third and fourth rectifiers and further connected to the second source of deflection voltage for supplying a net rectified current of a predetermined polarity to the second pair of deflection coils.