Color convergence apparatus for a color television tube

• US 3,891,889 A
• Filed: 02/06/1974
• Issued: 06/24/1975
• Est. Priority Date: 09/08/1972
• Status: Expired due to Term

• Current Assignee: Cae-Link Corporation
• Original Assignee: James Anthony Fazio
• Inventors: Fazio, James Anthony
• Primary Examiner(s): Wilbur, Maynard R.
• Assistant Examiner(s): Potenza, J. M.
• Application Number:
  US05/440,111
• Time in Patent Office: 503 Days
• Field of Search: 315/27TD,27R,27BC,27XY,276D,368
• US Class Current: 315/368.27
• CPC Class Codes: H04N 9/28 Arrangements for convergence or focusing

Abstract

The convergence coils of a convergence yoke are provided components of current which are related to currents in a deflection yoke.

Claims

1. Apparatus for providing convergence of the three beams from three electron guns, respectively, in a tri-color TV tube of the shadow mask type, the guns being disposed along a circle radially from an axis extending between the center of the screen and the base of the tube, deflection of the three beams on the screen of the tube being responsive to both periodic currents and nonperiodic currents provided to the horizontal and vertical coils of a deflection yoke around the neck of the tube, said tube also having a convergence yoke comprised of at least three convergence coils respectively corresponding to said guns, for providing additioNal deflection to each of said respective guns in response to convergence currents provided to each convergence coil comprising:

first and second sensing means connected to the horizontal and vertical deflection coils respectively for providing horizontal and vertical signals proportional to the horizontal and vertical deflection currents, including providing said horizontal and vertical signals when said deflection currents are periodic and when said deflection currents are nonperiodic;

first and second multiplying means connected to said first and second sensing means respectively, said first multiplying means being responsive to said horizontal signal and providing a first output signal proportional to the square of said horizontal signal, including providing said first signal when said horizontal signal is representative of a periodic signal and when said horizontal signal is representative of a nonperiodic signal, said second multiplying means being responsive to said vertical signal and providing a second output signal proportional to the square of said vertical signal, including providing said second signal when said vertical signal is representative of a periodic signal and when said vertical signal is representative of a non-periodic signal;

signal attenuating means connected to said horizontal, vertical, first and second signals for providing a plurality of selectively attenuated signals, including at least one attenuated signal for each of said horizontal, vertical, first and second signals; and

first, second and third combining means, each responsive to selected ones of said attenuated signals and each providing a convergence current representative of a combination of said attenuated signals to one of the convergence coils for providing convergence to the beams of the three electron guns when said beams are deflected in response to periodic currents and when said beams are deflected in response to non-periodic currents.

2. The apparatus of claim 1 wherein each of said combining means are responsive to said attenuated first and second signals.

3. Apparatus according to claim 2 additionally comprising third multiplying means responsive to said first and second signals provided by said first and second multiplying means for providing in two of said convergence coils components of convergence current proportional to the product of said first and second signals.

4. The apparatus of claim 2 wherein each of said combining means are responsive to said vertical signal.

5. The apparatus of claim 2 wherein two of said combining means are responsive to said horizontal signal.

6. Apparatus according to claim 2 additionally comprising fourth multiplying means responsive to said horizontal and vertical signals provided by said first and second sensing means for providing in two of said convergence coils components of convergence current proportional to the product of said horizontal and vertical signals.

7. Apparatus according to claim 2 wherein said guns include a blue gun aligned along a vertical diagonal of said circle, additionally comprising:

amplifier means responsive to said first sensing means for providing a lateral convergence current proportional to said horizontal signal; and

a lateral convergence coil, mounted around the neck of the tube and connected to said amplifier means to conduct said lateral convergence current, for tilting the beam of said blue gun in a direction tangent to the circle in response to said lateral convergence current.