US 4,620,133 AGranted

Color image display systems

AssigneeRCA Corporation

InventorsAlbert M. Morrell, Richard H. Hughes, William H. Barkow

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Abstract

Compact deflection yoke in self-converging display system encircles adjoining segments of neck and funnel sectons of color picture tube having close beam spacing (200 mils) in electron gun to achieve low S-spacing dimension between converging beams in deflection center plane. Neck diameter is sufficiently large (1145 mils) to accommodate main focusing lens having major transverse dimension more than three and half times the beam spacing in the electron gun. Main focusing lens is formed between final focus electrodes having recessed apertures at juxtaposed ends. Walls of successive recesses have "racetrack"-like and "dogbone"-like contours. Asymmetric beam forming lenses provide each beam traversing the main focusing lens with asymmetric cross-section having relatively reduced vertical dimension.

Claims25

Dependent claims

A color image display system comprising:

a color picture tube including an evacuated envelope comprising a screen portion enclosing a display screen, a cylindrical neck portion, and a funnel portion connecting said screen portion and said neck portion;
an electron gun assembly, mounted within said neck portion, for producing three in-line electron beams;
a compact deflection yoke assembly encircling adjoining segments of said neck and funnel portions for developing deflection fields which permit tracing of display rasters on said screen with substantial convergence of said beams throughout the display, and which establish a given deflection angle between beam paths which terminate at diagonally opposed raster corners, said yoke assembly including horizontal deflection windings of saddle configuration defining respective windows, and vertical deflection windings of toroidal configuration, establishing respective deflection centers for said beams within the encircled region of said envelope;
said gun assembly including two main focusing electrodes at the beam exit end of said gun assembly maintained at different potentials, each of said main focusing electrodes including:
a portion disposed transversely with respect to the longitudinal axis of said neck and having a trio of in-line apertures, through each of which a respectively different one of said beams passes;
and an adjoining portion extending longitudinally therefrom and providing a common enclosure for the paths of all of said beams, the respective adjoining portions of said electrodes being juxtaposed to define therebetween a common main focusing lens for said beams from which said beam paths depart in converging fashion;
wherein the center-to-center spacing between adjacent apertures of each of said trios is such as to restrict the center-to-center spacing of adjacent ones of said beams to less than 200 mils in transverse planes occupied by said delfection centers, wherein the configurations of said juxtaposed portions establish a major transverse dimension for said main focusing lens of significantly more than three times said center-to-center spacing between adjacent apertures, wherein the diameter of said neck portion is sufficiently great that the interior surface of said neck portion is spaced from the outer surfaces of said juxtaposed enclosures, and wherein the internal diameter of said compact yoke assembly at the beam exit end of said windows totals less than 30 mils per degree of said deflection angle.

4 more elements

A color image display system comprising:

a color picture tube including an evacuated envelope comprising a screen portion enclosing a display screen, a cylindrical neck portion, and a funnel portion connecting said screen portion and said neck portion;
an electron gun assembly, mounted within said neck portion, for producing three in-line electron beams;
and
a compact deflection yoke assembly encircling adjoining segments of said neck and funnel portions for developing deflection fields which permit tracing of display rasters on said screen with substantial convergence of said beams throughout the display, and which establish a given deflection angle between beam paths which terminate at diagonally opposed raster corners, said yoke assembly including horizontal deflection windings of saddle configuration defining respective windows, and vertical deflection windings of toroidal configuration, establishing respective deflection centers for said beams within the encircled region of said envelope;
wherein said electron gun assembly comprises:
focusing means for establishing a common, asymmetric, main focusing lens for said beams from which said beam paths depart in converging fashion, said focusing lens being disposed transversely with respect to the paths of said beams and exhibiting a major transverse dimension in a first direction which is greater than the maximum transverse dimension in a second direction orthogonal to the first;
and
means, preceding said focusing means, for shaping each of said beams so that the cross-section of each of said beams at the entrance of said focusing lens has a greater dimension in said first direction than in said second direction, said major transverse dimension of said focusing lens being more than three times the center-to-center spacing between adjacent ones of said beams at said lens entrance;
wherein said compact deflection yoke assembly includes a generally toroidal core of magnetizable material about which said vertical deflection windings are toroidally wound;
and
wherein the positioning of said horizontal deflection windings relative to said core is such as to locate the beam entrance end of said windows more remotely from said display screen than the beam entrance end of said core, and to offcenter said windows relative to said core's location in a direction away from said screen.

8 more elements

A color image display system comprising:

a color picture tube including an evacuated envelope comprising a screen portion enclosing a display screen, a cylindrical neck portion, and a funnel portion connecting said screen portion and said neck portion;
an electron gun assembly, mounted within said neck portion, for producing three in-line electron beams;
and
a compact deflection yoke assembly encircling adjoining segments of said neck and funnel portions for developing deflection fields which permit tracing of display rasters on said screen with substantial convergence of said beams throughout the display, and which establish a given deflection angle between beam paths which terminate at diagonally opposed raster corners, said yoke assembly including horizontal deflection windings of saddle configuration defining respective windows, and vertical deflection windings of toroidal configuration, establishing respective deflection centers for said beams within the encircled region of said envelope;
wherein said electron gun asesmbly comprises:
focusing means for establishing a common, asymmetric, main focusing lens for said beams from which said beam paths depart in converging fashion, said focusing lens being disposed transversely with respect to the paths of said beams and exhibiting a major transverse dimension in a first direction which is greater than the maximum transverse dimension in a second direction orthogonal to the first;
and
means, preceding said focusing means, for shaping each of said beams so that the cross-section of each of said beams at the entrance of said focusing lens has a greater dimension in said first direction than in said second direction, said major transverse dimension of said focusing lens being more than three times the center-to-center spacing between adjacent ones of said beams at said lens entrance;
and wherein the internal diameter of said compact yoke assembly at the beam exit end of said windows totals less than 30 mils per degree of said deflection angle.

6 more elements

Dependencies are inferred from the claim text.