Tracking picture tube
AssigneeKoninklijke Philips Electronics N.V.
InventorsHendrikus Bernardus Van Den Brink, Hans-Helmut Bechtel, Marcellinus Petrus Carolus Michael Krijn
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Abstract
The present invention relates to a tracking picture tube of the type in which comb-shaped electrodes or optical detecting means (12, 13) are used for generating a signal related to the position of an electron beam with respect to the strips (5). The tube is characterized in that the deflection unit is arranged to deflect the beams (21r, 21g, 21b) onto selected strips (22r, 22g, 22b) having coincident sides which neighbour finger portions (14, 15) of the same electrode (12, 13), and the selected strips (22r, 22g, 22b), excited by the electron beams, are separated by at least one unexcited strip, respectively.
Claims12
A picture tube (1) comprising
- a screen (2) with a plurality of interspersed sets of parallel strips (5a, 5b, 5c) of light-emitting material, each set emitting light of a specific color when hit by electrons,
- a plurality of electron guns (4), each adapted to generate an electron beam (9) associated with the strips in one of said sets of strips,
- a deflection unit (10) for deflecting each electron beam onto one of the strips in the corresponding set of strips, thereby exciting this strip to emit light, and
- at least one pair of comb-shaped electron-detecting means (12, 13) having a plurality of interdigitated finger portions (14, 15) extending parallel with the strips (5), for generating a signal (18) relative to the position of an electron beam (9) with respect to the strips (5),
- characterized in that the deflection unit (10) is arranged to deflect the beams onto selected strips (22r, 22g, 22b) having coincident sides which neighbour finger portions (14, 15) of the same detecting means (12, 13), said selected strips (22r, 22g, 22b),excited by the electron beams, being separated by at least one unexcited strip, respectively.
Dependencies are inferred from the claim text.