Abstract: Apparatus, associated with a cathode ray tube (CRT), containing both a electrostatic focusing lens and a magnetic focusing lens for maintaining the focus of an electron beam within the CRT at any location on a CRT screen. The apparatus applies a dynamic focusing voltage to an electrostatic focus grid of an electron gun and applies a dynamic focusing current to a magnetic focus coil. The focusing voltage and current vary in accordance with the position of the electron beam on the screen. As such, the electron beam remains focused upon the screen for all beam positions.

Abstract: A color picture tube includes a faceplate and a funnel attached to the faceplate. The faceplate has a horizontal dimension M.sub.h and a vertical dimension M.sub.v, with the dimensions having a ratio M.sub.h /M.sub.v greater than one. A magnetic shield is located within the tube. The magnetic shield has a front aperture in the proximity of the faceplate and a rear aperture remote from the faceplate. The front aperture has a horizontal dimension F.sub.h and a vertical dimension F.sub.v and the rear aperture has a horizontal dimension R.sub.h and a vertical dimension R.sub.v. The top and bottom of the rear aperature are close to the sides of the funnel and the sides of the rear aperture are spaced from the funnel by a spacing consistent with the entrance of the electron beams at maximum deflection into the shield.

Abstract: The present invention provides an improvement in color picture tubes. Such tubes include an electron gun for generating and directing three inline electron beams, a center beam and two side beams, along initially coplanar paths toward a screen of the tube. The gun includes a plurality of spaced electrodes which form a main focus lens for focusing the electron beams. The improvement comprises the plurality of spaced electrodes which form a main focus lens including three electrodes that form an einzel lens in the path of each electron beam. A first einzel lens electrode includes three inline cylinders through which the electron beams pass. A second einzel lens electrode includes a large oval cylinder that overlaps all three cylinders of the first einzel lens electrode. A third einzel lens electrode includes three inline cylinders which are overlapped by the oval cylinder.

Abstract: The present invention provides an improvement in color picture tubes. Such tubes include an electron gun for generating and directing three inline electron beams, a center beam and two side beams, along initially coplanar paths toward a screen of the tube. The gun includes a plurality of spaced electrodes which form a main focus lens for focusing the electron beams. The improvement comprises the plurality of spaced electrodes which form a main focus lens including four electrodes that form an einzel lens in the path of each electron beam. A first einzel lens electrode includes a first portion having three inline apertures that are set back from a second portion having a single large aperture through which all three electron beams pass. A second einzel lens electrode includes a first portion having three inline apertures that are set back from a second portion having a single large aperture through which all three electron beams pass.

Abstract: 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 in a first direction perpendicular to the inline direction of the beams, and a second of the fields causes deflection in a second direction parallel to the inline direction of the beams. The gun includes two shunts for shunting portions of both deflection fields around the outer beam paths. Each shunt comprises one magnetically permeable member having an aperture therein. Each shunt completely surrounds one of the electron beam paths.

Abstract: A color display system includes a cathode-ray tube and yoke. The yoke is a non-converging type. The cathode-ray tube has en electron gun assembly for generating and directing three electron beams, located at the corners of an equilateral triangle, along paths toward a screen of the tube. The electron gun assembly comprises three electron guns each including electrodes that comprise a beam-forming region and electrodes that form a main focusing lens in the path of each electron beam. The main focusing lens is formed by at least two focusing electrodes. The focusing electrode closest to the beam-forming region includes a separated part adjacent to the paths of each of the electron beams. Each separated part forms a portion of the dipole lens structure in the path of an electron beam. Means are provided for applying dynamic signals to the separated parts which are related to the deflection of the electron beams.

Abstract: An improved 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 the 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 means for nonlinearly increasing the effect of the vertical magnetic deflection field on the center beam relative to the outer beams with increasing angles of vertical deflection of the beams.

Abstract: The present invention is an improvement in an electron gun for use in a cathode ray tube. Such gun includes at least one cathode and a plurality of electrodes spaced from the cathode. At least two of the electrodes form a main focusing lens and the electrode nearest the cathode which forms the main focusing lens includes extrusions about an aperture therein. The improvement comprises means located at the end of the gun opposite the cathode for blocking the exit from the gun of electrons emitted from the extrusions.

Abstract: 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 focusing lens for focusing the electron beams. The main focusing lens is formed by two spaced electrodes, 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 recesses of the electrodes have substantially the same dimension perpendicular to the inline directions of the inline apertures as the dimension parallel to the inline direction of the inline apertures. However, the recesses have lesser dimensions along diagonals angled at approximately 45 degrees with respect to the inline direction of the inline apertures.

Abstract: 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 prefocus lens electrodes and main focus lens electrodes for focusing the electron beams. The main focus lens is formed by two spaced electrode members. The improvement includes the combination of features related to these two electrode members. One of the electrodes forming the main focus lens is an internal conductive coating on the neck. The other electrode includes three parts. First, there is a cylindrical portion that is smaller in diameter than the neck and is located in overlapped relation with respect to the conductive internal coating. Second, an apertured portion of the electrode includes three inline apertures which are aligned with the electron beam paths.

Abstract: An improvement is made 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 which is formed by two spaced electrodes. Each electrode includes a portion having a plurality of apertures therein equal to the number of electron beams. Each electrode also includes a peripheral rim. The peripheral rims of the two electrodes face each other and the apertured portion of each electrode is within a recess set back from the rim. The improvement comprises the depths of the apertures in the electrodes being equal to the thickness of material of the electrodes. This aperture structure permits greater penetration of the electrostatic lines of the main focus lens into the electrodes behind the apertured portions of the electrodes. This penetration of electrostatic lines provides a converging field for off-axis electron beams.

Abstract: In a television receiver comprising a display system incorporating a kinescope having horizontal in-line electron beams and also incorporating a deflection yoke having toroidally-wound vertical deflection coils, where the kinescope utilizes a magnetically-permeable G3 focussing electrode in the electron guns to reduce deflection defocussing, an arrangement for correcting misconvergence of the electron beams caused by the magnetically-permeable G3 electrode comprises a pair of magnetically-permeable field formers disposed along and extending toward the rear of the yoke. The field formers are configured to collect a portion of the external fields generated by the vertical windings and direct those portions through the kinescope neck substantially at right angles to the electron beams in the vicinity of the exit end of the electron guns with a barrel-shaped transverse pattern.

Abstract: A cathode-ray tube comprises an evacuated envelope having therein a target and an electron-beam-producing means including a field-emission cathode therein. The beam-producing means comprises a plurality of spaced, pointed protuberances pointing in the same direction. Each protuberance has its own field-emission-producing means, a separate focusing-field-producing means for focusing the electrons emitted from the protuberance into a beam and means for modulating the individual beams in concert. The structure produces a plurality of modulated beams that are projected as a bundle in substantially parallel paths, which may be further operated upon as a single composite beam.