Koninklijke Philips Corporation N.v.

Pieter Johannes Engelaar

Petrus Johannes Gerardus Van Lieshout

Adrianus Sempel

Picture display device comprising a cathode ray tube whose display screen ( ) is provided with index electrodes ( ) comprising elongated conducting elements disposed substantially parallel to an axis of symmetry ( ) of the display screen ( ). In operation, the magnetic field of the deflection system of the cathode ray tube induces unwanted crosstalk on said index electrodes ( ). By cross-connecting one end ( ) of a conducting element ( ) of an index electrode ( ) to the opposite side end ( ) of another conducting element ( ) of said index electrode ( ), said crosstalk on said index electrode ( ) is reduced.

Picture display device of the index type

A tracking index cathode ray tube circuit includes a tracking circuit connected to a shadowmaskless tracking cathode ray tube for deriving a tracking signal therefrom. The tracking circuit comprises a modulator demodulator circuit. The tracking signal from the CRT tube is thus modulated, AC coupled to a low voltage and demodulated to obtain a baseband tracking signal for use as a control signal for the electron beam spots on the screen of the CRT tube.

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Eindhoven, Netherlands

Pieter Johannes Engelaar