Linearity correction circuit for a cathode ray tube

Claim 2

In a circuit for deflecting the beam of a cathode ray tube along one axis of the cathode ray tube screen, a circuit for compensating for nonlinearity along that axis as a function of the deflection wave for deflecting said beam along a second axis of said screen, in combination: an active element having a control electrode, an input electrode to which an input signal may be applied, an output electrode where an output signal is manifested, and a conduction path insulated from said control electrode extending between the input and output electrodes, whose impedance may be varied in response to a signal applied to the control electrode; means for applying a deflection wave for said one axis to said input electrode; and means for applying said deflection wave for said second axis to said control electrode for varying the impedance of said conduction path.

Claim 3

The combination claimed in claim 1, including a deflection means for said one axis and further including means for applying without correction the signal manifested at said output electrode to said deflection means.

Claim 4

The combination claimed in claim 1, including means for shifting the level of the signal manifested at said output electrode.

Claim 5

The combination claimed in claim 1, said active element comprising a field effect transistor.

Claim 6

In a linearity correction circuit for a display device having deflection means, the combination comprising: an active element having a control electrode, an input electrode to which an input signal may be applied, an output electrode where an output signal is manifested, and a conduction path extending between the input and output electrodes, whose impedance may be varied in response to a signal applied to the control electrode; means for appLying an on-axis deflection wave to said input electrode; means for separately applying an off-axis deflection wave which is isolated from said on-axis deflection wave to said control electrode for varying the impedance of said conduction path; and means for applying, without further linearity correction, the signal present in said conduction path to the deflection means for said display device.

Claim 7

In a linearity correction circuit for a display device having deflection means, the combination comprising: an active element having a control electrode, an input electrode to which an input signal may be applied, an output electrode where an output signal is manifested, and a conduction path extending between the input and output electrodes, whose impedance may be varied in response to a signal applied to the control electrode; means for appLying an on-axis deflection wave to said input electrode; means for separately applying an off-axis deflection wave which is isolated from said on-axis deflection wave to said control electrode for varying the impedance of said conduction path; and means for applying, without further linearity correction, the signal present in said conduction path to the deflection means for said display device.

Claim 8

In a linearity correction circuit for a display device, the combination comprising: an active element having a control electrode, an input electrode to which an input signal may be applied, an output electrode where an output signal is manifested, and a conduction path insulated from said control electrode extending between the input and output electrodes, whose impedance may be varied in response to a signal applied to the control electrode; means for applying a nonlinear on-axis deflection wave to said input electrode; and means for applying a nonlinear off-axis deflection wave to said control electrode for varying the impedance of said conduction path.

Claim 9

In a linearity correction circuit for a display device, the combination comprising: an active element having a control electrode, an input electrode to which an input signal may be applied, an output electrode where an output signal is manifested, and a conduction path insulated from said control electrode extending between the input and output electrodes, whose impedance may be varied in response to a signal applied to the control electrode; means for applying a nonlinear on-axis deflection wave to said input electrode; and means for applying a nonlinear off-axis deflection wave to said control electrode for varying the impedance of said conduction path.

Claim 10

The combination claimed in claim 6, including means for applying a portion of a linear off-axis deflection wave to said output electrode.

Claim 11

The combination claimed in claim 7, wherein said on-axis and off-axis deflection means include means providing the necessary linearity correction and further including a deflection means and a means for applying the signal manifested at said output electrode to said deflection means.

Claim 12

In a circuit for deflecting the beam of a cathode ray tube along one axis of the cathode ray tube screen, a circuit for compensating the nonlinearity along that axis as a function of the deflection wave for deflecting said beam along a second axis of said screen, in combination: an active element having a control electrode, an input electrode to which an input signal may be applied, an output electrode where an output signal is manifested, and a conduction path extending between the input and output electrodes, whose impedance may be varied in response to a signal applied to the control electrode; means for applying a first nonlinear deflection wave for said one axis to said input electrode; means for applying a second nonlinear deflection wave for said second axis which is isolated from said first wave to said control electrode for varying the impedance of said conduction path; means for applying a portion of a linear deflection wave for said second axis to said output electrode; and a deflection means for said one axis and means for applying the signal manifested at said output electrode to said deflection means.

Claim 13

In a circuit for deflecting the beam of a cathode ray tube along one axis of the cathode ray tube screen, a circuit for compensating the nonlinearity along that axis as a function of the deflection wave for deflecting said beam along a second axis of said screen, in combination: an active element having a control electrode, an input electrode to which an input signal may be applied, an output electrode where an output signal is manifested, and a conduction path extending between the input and output electrodes, whose impedance may be varied in response to a signal applied to the control electrode; means for applying a first nonlinear deflection wave for said one axis to said input electrode; means for applying a second nonlinear deflection wave for said second axis which is isolated from said first wave to said control electrode for varying the impedance of said conduction path; means for applying a portion of a linear deflection wave for said second axis to said output electrode; and a deflection means for said one axis and means for applying the signal manifested at said output electrode to said deflection means.

Claim 14

In a circuit for deflecting the beam of a cathode ray tube along one axis of the cathode ray screen, a circuit for compensating for nonlinearity along that axis as a function of the deflection wave for deflecting said beam along a second axis of said screen, in combination: an active element having a control electrode, an input electrode to which an input signal may be applied, an output electrode where an output signal is manifested, and a conduction path extending between the input and output electrodes, whose impedance may be varied in response to a signal applied to said control electrode; means for applying a deflection wave for said one axis to said input electrode; absolute magnitude means receptive of an input wave for said second axis, which wave has excursions above and below a reference level for producing a unipolar wave having a value equal to the absolute magnitude of the difference between the input wave value and reference level value; and means responsive to said unipolar wave for producing a nonlinear signal as a function of said unipolar wave, said nonlinear signal being applied to said control electrode for varying the impedance of said conduction path.

Claim 15

In a circuit for deflecting the beam of a cathode ray tube along one axis of the cathode ray screen, a circuit for compensating for nonlinearity along that axis as a function of the deflection wave for deflecting said beam along a second axis of said screen, in combination: an active element having a control electrode, an input electrode to which an input signal may be applied, an output electrode where an output signal is manifested, and a conduction path extending between the input and output electrodes, whose impedance may be varied in response to a signal applied to said control electrode; means for applying a deflection wave for said one axis to said input electrode; absolute magnitude means receptive of an input wave for said second axis, which wave has excursions above and below a reference level for producing a unipolar wave having a value equal to the absolute magnitude of the difference between the input wave value and reference level value; and means responsive to said unipolar wave for producing a nonlinear signal as a function of said unipolar wave, said nonlinear signal being applied to said control electrode for varying the impedance of said conduction path.

Claim 16

The combination as set forth in claim 10 further including means coupled to said output terminal for producing a deflection signal for deflecting said beam along said one axis as a linear function of said resistance of said active element.