Rca Inc.

Richard H Hughes

Hsing-Yao Chen

Bruce G Marks

Albert M Morrell

William H Barkow

Naim Z Assil

Dennis J Bechis

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.

Color image display systems

A color picture tube includes a screen and an improved inline gun for generating and directing three inline electron beams along separate paths toward the screen. The improved electron gun has an asymmetric beam-forming region and an asymmetric main focus lens. The asymmetry of the main focus lens is matched with the asymmetry of the beam-forming region to focus substantially all portions of each of the beams at the screen.

Color picture tube having an inline electron gun with asymmetric

The present invention provides an improvement in a color picture tube having an inline electron gun for generating and directing three inline electron beams, comprising a center beam and two outer beams, along initially coplanar paths toward a screen of the tube. The beams pass through a deflection zone adapted to have two orthogonal magnetic deflection fields established therein. A first of the fields causes deflection of the beams perpendicular to the inline direction of the beams, and a second of the fields causes deflection parallel to the inline direction of the beams. The improvement comprises the electron gun including four magnetically permeable members located near the exit of the electron gun in a fringe portion of said deflection zone. A first and a second of the members are located between the center beam path and a first and second outer beam path, respectively. A third and a fourth of said members are spaced from the first and second members, respectively, and are located on the outside of the respective outer beam paths. The first and third members and the second and fourth members have means for bypassing a part of the fringe portion of the first of the two orthogonal magnetic deflection fields, at the members, around the respective outer beam paths, while allowing another part of the same fringe portion, at the members, to pass through the respective outer beam paths. The first and second members have means for bypassing a part of the fringe portion of the first of the two orthogonal deflection fields, at the members, around the center beam path, while allowing another part of the same fringe portion, at the members, to pass through the center beam path.

Color picture tube having inline electron gun with coma correction

An inline electron gun in a color picture tube is improved by the addition of two slot apertures that are spaced sufficiently close to and outward from the two outer apertures in a portion of a focusing electrode facing a screen grid electrode to cause a distortion of the electrostatic field formed between the two electrodes at the two outer apertures. The electrostatic field distortion causes two outer electron beams to converge toward a center electron beam.

Color picture tube with focusing electrode having electrostatic field

An improved color picture tube has an inline electron gun for generating and directing three electron beams, a center beam and two side beams, along coplanar paths toward a screen of the tube. The gun includes a main focus lens for focusing the electron beams. The main focus lens is formed by two spaced electrode members each having three separate inline apertures therein. Each electrode also includes a peripheral rim. The peripheral rims of the two electrodes face each other. The apertured portion of each electrode is within a recess set back from the rim. The main focus lens electrode closest to the screen includes a slot on the side facing the screen. The slot extends in the direction of the three electron beam paths. The slot is wider, in a direction perpendicular to the plane of the three electron beam paths, at the side beam paths than at the center beam pa

Color picture tube having an expanded focus lens type inline electron

A color picture tube has an inline electron gun for generating and directing three electron beams, comprising a center beam and two outer beams, along coplanar paths toward a screen of said tube. The three beams pass through a deflection zone adapted to have vertical and horizontal magnetic deflection fields established therein. The improvement comprises the inclusion of first means for weakening the effect of a portion of the horizontal magnetic deflection field on the center electron beam. Such means include elongated magnetic members located between the outer beams and the center beam with the direction of elongation being perpendicular to the plane of the electron beam paths. Also included are second means for weakening the effect of portions of both deflection fields on the two outer beams. The second means includes magnetic shield members completely surrounding each of the outer beam paths.

Color picture tube with means for affecting magnetic deflection fields

The present invention relates to an improvement in a color picture tube having an inline electron gun, for generating and directing a plurality of electron beams along coplanar paths toward a screen of the tube. The gun includes a main focus lens for focusing the electron beams. The improvement comprises a change in the two spaced gun electrodes that form the main focus lens. Each electrode includes a plurality of apertures therein equal to the number of electron beams. Each electrode also includes a peripheral rim with the peripheral rims of the two electrodes facing each other. The apertured portion of each electrode is located within a recess set back from the rim. The recess has substantially straight wall sections parallel to the paths of the electron beams.

Color picture tube having an improved inline electron gun with an

A 3-beam in-line electron gun comprises a pair of tub-shaped lens electrodes, each of which has three in-line apertures in its floor with tubular lips extending from the periphery of the apertures into the tubs. The lips of the lower voltage electrode are longer than the corresponding lips of the higher voltage electrode by an amount designed to either balance out the astigmatism of the fringe focus fields within the tubs or perferably to completely reverse the polarity of the overall astigmatism to at least partially compensate for the astigmatism of a self-converging yoke used with the gun.

Electron gun with balanced lens lips to reduce astigmatism

The electron gun, which is especially adapted for use in color picture tubes, comprises in the order named: a cathode, an apertured-plate control grid (G1), an apertured-plate screen grid (G2), and at least two tubular focusing electrodes. The quality of the gun's beam spot is improved by: 1. Establishing an operating electric field between the G2 and G3 which is between about 100 and 400 volts/mil, thereby reducing aberration effects in the beam-forming region of the gun; 2. Making the G2 thick so as to prevent the high G3 voltage from penetrating the region between the G1 and G2, thereby allowing the G1-G2 field to provide a divergent effect on the electron beam prior to beam crossover and thus give a reduced crossover angle; 3. Spacing the main focusing lens at a distance from the G2 so as to provide an optimum filling of the main focus lens with the beam to maximize the object distance of the focusing system; and 4. Structuring the G2 and G3 to provide a flat electrostatic field therebetween to avoid prefocusing action in that region, so as not to cause an effective reduction of the object distance of the focusing system.

High potential, low magnification electron gun

The present invention relates to an improvement in a color picture tube having an inline electron gun for generating and directing a plurality of electron beams, along coplanar paths toward a screen of the tube. The gun includes a main focus lens for focusing the electron beams. The improvement comprises a change in the gun electrodes that form the main focus lens. The main focus lens is formed by two spaced electrodes. Each electrode includes a member having a plurality of apertures therein equal to the number of electron beams and a lens plate spaced from the member which is electrically connected to the member. The lens plates of the two electrodes are adjacent and spaced from each other and are located between the members of the electrodes having a plurality of apertures therein. Each lens plate includes a signal large hole therein formed by a plurality of overlapping apertures equal to the number of electron beams.

Color picture tube having an improved electron gun with expanded lenses

The gun, for use in a television picture tube, comprises a cathode, an apertured control grid, and an apertured screen grid aligned in the order named. The screen grid aperture comprises a rectangular slot portion facing the control grid and a circular portion facing away from the control grid. The slot portion of the aperture, which has a width 2-5 times its depth, creates an astigmatic field that produces underconvergence of the electron beam in the vertical plane only, whereby to avoid and/or compensate for vertical flare distortion of the beam spot at off-center positions on the image screen.

Electron gun with astigmatic flare-reducing beam forming region

An inline electron gun includes means for weakening the effect of a portion of the horizontal magnetic deflection field on the center electron beam and for strengthening the effect of a portion of the vertical magnetic deflection field on the center electron beam. The means includes magnetic shield members completely surrounding the paths of the outer beams. Each of the members has a portion that crosses the plane of the co-planar electron beam paths that is closer to the center beam path than to the outer beam paths. In a preferred embodiment, large shunts surrounding the outer beams are offset eccentrically toward the center beam relative to the outer beams.

CRT generating three inline beams and having shunts for weakening center

An in-line electron gun assembly for a color television picture tube has a center cathode disposed between two outer cathodes. The cathodes are substantially coplanar and each is supported at a predetermined distance from a control grid by a separate cathode support structure. Each cathode support structure includes a cathode eyelet. The center cathode eyelet is formed of a material having a smaller coefficient of thermal expansion than that of the two outer cathode eyelets so that the variations in carthode-to-grid spacing due to temperature changes during warm-up are kept substantially equal from cathode to cathode.

Growing community of inventors

Lancaster, PA, United States of America

Richard H Hughes