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AssigneeU.S. Philips Corporation
InventorJan Gerritsen
Estimating the term…
A color television display device comprising a deflection coil unit with a deflection coil for the vertical deflection which coil is divided into two coil halves. A balancing resistor by means of which the convergence can be corrected is in a parallel branch. A static convergence error introduced by this resistor owing to the non-zero inductance of the deflection coil is corrected by means for decreasing the voltage present across the balancing resistor during the trace period of the deflection current by a direct voltage in such a way that the voltage across the resistor is more decreased after the center instant of the trace period than before and that the correction current at and about said center instant is substantially zero. (FIG. 3).
A color television display device comprising a color picture display tube and a deflection coil unit provided with a deflection coil for deflecting into the vertical direction the electron beams generated in the display tube, the coil being divided into two series-interconnected coil halves and being connected to a deflection current generator for generating a sawtooth deflection current flowing in operation through the deflection coil halves and having a trace and a retrace which reverses its direction at approximately the center instant of the trace period and further provided with an adjustable balancing resistor in a parallel branch which produces a correction circuit which flows through the deflection coil halves, wherein said device further comprises means for decreasing, during the trace period of the deflection current, the voltage present in operation across the parallel branch including said balancing resistor by a constant voltage in such a way that the voltage across said parallel branch is more decreased after said center instant than before and that the correction current at and about said center instant is substantially zero.
A deflection coil unit for a color television display device, provided with a deflection coil for the horizontal deflection, with a deflection coil for the vertical deflection which is divided into two series-interconnected coil halves and with an adjustable balancing resistor in a parallel branch, wherein said deflection coil unit further comprises two series arrangements of a substantially constant-voltage drop element, a switch in parallel therewith, and a balancing resistor, each series arrangement being in parallel with a coil half.
Dependencies are inferred from the claim text.