Kabushiki Kaisha Toshiba

Jiro Shimokobe

Eiji Kamohara

Taketoshi Shimoma

Shigeru Sugawara

Katsuei Morohashi

Takashi Nishimura

Taketoshi Shimona

In a color cathode ray tube apparatus wherein three in-line electron beams are deflected by horizontal and vertical deflection magnetic fields of a deflector. The three in-line electron beams are arranged along an axis that is inclined with respect to a horizontal axis perpendicular to the tube axis and are emitted from an electron beam producing unit. Of the three electron beams, the center beam is focused at a higher degree than the pair of side beams by an electric field lens forming unit. The pair of side beams are deflected by a deflecting unit in the direction of arrangement of the three electron beams away from the center beam and are made incident on a focusing magnetic field generating device constituting a common magnetic field focusing type electron lens for focusing and converging the three electron beams. Then, the three electron beams are directed to a phosphor screen. Accordingly, the electron beams are desirably focused and converged on the phosphor screen with a small beam spot size.

Color cathode ray tube apparatus

In a color picture tube apparatus having a first auxiliary deflecting means for deflecting a single electron beam, emitted from a cathode, in a direction to separate from the tube axis in synchronism with switching among a plurality of video signals supplied to an electron gun, and splitting the single electron beam substantially into a plurality of beam segments, and a second auxiliary deflecting means, disposed between the first auxiliary deflecting means and a main deflecting unit, for deflecting the plurality of beam segments in a direction to come close to the tube axis, the first auxiliary deflecting means is constituted by an electrostatic deflecting lens provided to an accelerating electrode system between a control electrode and a focusing electrode of the electron gun, and the second auxiliary deflecting means is constituted by a main electron lens of the electron gun for finally focusing the electron beam segments on a phosphor screen. Accordingly, the entire length of the picture tube can be shortened, and the auxiliary deflecting power can be reduced as well as the manufacturing cost.

Color picture tube apparatus

In an electron gun assembly, electron beams emitted from cathodes are focused in first cross-over and accelerated and controlled by grids along three axes arranged in-line. The controlled electron beams are weakly converged by unipotential lenses and are converged in a vertical plane by a common single electron lens having a lens power which is varied in accordance with a horizontal or vertical deflection of the electron beams. The converged electron beams form second cross-over on the axes which are shifted along the axes are diverged from the second cross-overs. The diverged electron beams are further focused and converged onto a screen by a main lens.

Color cathode-ray tube apparatus

In a electron gun assembly, three in-line electron beams are generated from three cathodes and are controlled and accelerated by a prefocusing electron lens, and each of the electron beams is converged by unipotential electron lens. In a horizontal plane, the electron beams are collimated by a quadruple lenses and are incident on a single and common large-diameter main electron lens. In a vertical plane, each of the electron beams is emerged as a divergent electron beam from the quadruple lens and each of the divergent electron beams is incident on the main electron lens. Thus, each of the electron beams are correctly focused on a screen and the three electron beams are correctly converged on a convergent point by the main electrode lens.

Electron gun assembly for a color cathode ray tube

In a color cathode ray tube apparatus of this invention, an electron beam forming unit of an electron gun outputs electron beams to have an interval of 3.5 to 6.0 mm between adjacent beams, and a ratio of a neck inner diameter to the interval between the adjacent electron beams is 5.1 or more. The main lens unit of the electron gun has a large-aperture electron lens formed by a substantially cylindrical first electrode for allowing three electron beams to pass therethrough, and a substantially cylindrical second electrode in which most of the first electrode is arranged.

A color cathode ray tube apparatus is provided with an electron gun which has a common large-aperture electron lens on which three electron beams are incident. Since the electron gun has individual electron lenses for individual electron beams, the electron beams can be properly converged and focused on a screen. Thus, the apparatus enjoys a satisfactory picture characteristic.

In a color cathode ray tube apparatus of this invention, if an outer diameter of a neck having a cylindrical shape is represented by D.sub.N and an interval of adjacent electron beams at a screen-side end portion of an electron gun is represented by Sg, a value D.sub.N /Sg is 8.0 or more. A deflection means has a saddle-type horizontal deflection coil for deflecting electron beams in an in-line direction. If the length of the deflection means in a direction of the tube axis is represented by l.sub.H all, l.sub.H all is 90 mm or more.

In a color cathode ray apparatus, three electron beams emitted from electron gun assembly are correctly converged on a peripheral region of a peripheral region of a phosphor screen and are weakly converged on a center region of the phosphor screen by static convergence means. The electron beams are also converged by dynamic convergence means so as to correct the weak convergence in accordance with a horizontal deflection of the electron beams. Thus, the electron beams can be correctly converged all over the phosphor screen.

Color cathode ray apparatus provided with dynamic convergence means

In a color cathode-ray apparatus, electron beams emitted from an electron gun assembly are deflected along horizontal and vertical axes by horizontal and vertical deflecting units. The horizontal deflecting unit includes first and second horizontal deflecting yokes which are located such that the center of the second horizontal deflecting yoke is defined between the center of the first horizontal deflecting yoke and the electron gun assembly. First and second horizontal deflection currents are supplied to the first and second horizontal deflecting yokes and are changed in different manners, in accordance with a degree to which the electron beams are to be deflected, and the first and seocnd deflection yokes generate pincushion and barrel magnetic fields, respectively.

Color cathode-ray apparatus having an improved deflection unit

In a color cathode ray tube, electron beams generated from an electron gun assembly of an in-line type are deflected by horizontal and vertical deflection magnetic fields. The horizontal deflection magnetic field includes a main magnetic field and an auxiliary magnetic field. The main magnetic field has a barrel-shaped distribution and is substantially symmetrically formed about a Y-Z plane and the auxiliary magnetic field is substantially antisymmetric about the Y-Z plane.

Growing community of inventors

Fukaya, Japan

Jiro Shimokobe