Matsushita Electronics Corporation

Kakuichiro Hosokoshi

Shigeya Ashizaki

Hiroto Nakamura

Akira Sato

Osamu Konosu

Masayuki Tanaka

Osamu Adachi

Masao Natsuhara

Takami Okamoto

Shinichi Omura

Osamu Yoshida

Masakazu Maeda

Koichi Sugawara

Hikoshi Yamamoto

In a color picture tube, curvature of outside face of said face panel is defined by ##EQU1## wherein Z is a distance in a direction of tube axis from an X-Y plane tangential at the center of the face, r is a distance from the center of the face panel to said point therealong, and A and B are constants of positive integers, respectively; thus the face panel excludes point of inflection and the reproduced picture thereon has a flat appearance, without trouble of undesirable doming of shadow mask.

Color picture tube having a face panel with an outer face having a

An auxiliary grid which is formed with one or more elongated slits through which pass electron beams is disposed in a prefocusing system in a cathode-ray tube, and a dynamic voltage which varies in level with increase in horizontal deflection angle is applied to the auxiliary grid so that axial asymmetry of the prefocusing system can be increased with increase in the horizontal deflection angle. As a consequence, the beam spot can be maintained substantially in the form of a true circle not only at the center of the screen but also at the portions adjacent to the peripheries thereof. Thus, the resolution at the portions adjacent to the peripheries of the screen can be improved and consequently high-quality images can be represented over the whole surface of the screen.

Cathode-ray tube device

A color picture tube, wherein a set of three electron beams emitted from respective three electron-emitting members of an electron gun, or from respective three electron guns, is projected onto a screen, and sets of each three luminous strips on this screen are selectively energized to emit luminous color lights, characterized in that the numeral ratios between said luminous strips by pieces and said slots of the shadow mask, respectively, are about 1:1 vertically and about 3:1 horizontally, and also that every strip as well as its set is complete insulated from adjacent strips and their sets by a light-absorbent film filling all the gaps inbetween. With such construction, a color picture tube having excellent brightness and contrast characteristic, being free from disturbing vertical strips, has been obtained.

Shadow mask having vertical pitch about 8/(2n-1) times horizontal pitch

A color television tube assembly in which the aperture of a control grid of each electron gun is made in the form of an ellipse with its major axis in line with the vertical direction, and the lengths of the vertical and horizontal axes of the aperture of action space of an electron lens electrode are selected different from each other, whereby the beam spot at the center of the screen may become in the form of a vertically elongated ellipse while the beam spots at the horizontal and vertical edges of the screen are in the form of a horizontally elongated ellipse.

In line electron guns for color tubes, each having a control grid with

In a process for exposing a photosensitive layer formed upon the inside of the faceplate of a color-picture tube so as to form a desired pattern of phosphor dots or temporary dots or the like, an optical correction system for causing the light beam to precisely impinge at a point where the electron beam impinges is interposed between a light source and a shadow mask. The system comprises an optical lens system for correcting .DELTA.S deviation characteristics and an optical lens system for correcting .DELTA.P deviation characteristics consisting of a first optical correction system and a second optical system. The first optical system is so designed as to attain the average correction depending only upon the deflection angle regardless of each of the radial directions of deflection while the second optical system is so designed as to attain the individual .DELTA.P deviation characteristics depending not only upon the deflection angle but also upon each of the radial directions of deflection. The correction lenses may have a relatively simple aspherical surface.

Method for manufacturing the phosphor screen of color-picture tube

A light exposing apparatus for use in forming a phosphor screen of a color cathode ray tube is disclosed in which a control means is connected to a movable platform for relatively moving a light sensitive film mounted on an inner surface of a face panel relative to an exposing light source facing said light sensitive film with a shadow mask interleaved therebetween. An electrical signal is supplied to said control means each time the accumulated value of ultraviolet ray emitted from said light source reaches a predetermined value, and said movable platform is moved lengthwise of slots in said shadow mask depending on the magnitude of said electrical signal during the light exposing process.

Light exposing apparatus for forming a phosphor screen of a cathode ray

This invention concerns an improvement in manufacturing of color picture tubes wherein photosensitive slurry is applied on the inner surface of a face panel of the tube and dried to form a dried slurry, then a shadow mask is secured to the face panel with a specified gap in between, and ultraviolet rays impinge on the dried slurry layer through a path-refracting lens and apertures of said shadow mask so as to form dots on the inner surface. The improvement lies in provision of a light attenuator to control exposure distribution of the ultraviolet rays closely beneath the shadow mask. With this arrangement, sizes of the dots in the edge part of a screen can be made almost equal irrespective of changes of position of the ultraviolet ray source. Consequently, the dots for the three colors in the edge portion of the screen can be made substantially equal in size, and good color balance throughout the picture screen is obtainable.

Method of manufacturing color picture tubes using rotating light

The invention discloses a method and apparatus for manufacture of color television picture tubes of the type having a shadow mask with a multiplicity of slots, and more particularly for selectively exposing a light sensitive film uniformly coated over the inner surface of a face-panel in order to form the temporary dots or strips. The exposure light source is rotated in the form of a ring while it is displaced relative to the light sensitive film in the longitudinal direction of the slots in a shadow mask, whereby the spacing in the longitudinal direction between the adjacent exposed areas or light images projected may be advantageously reduced without reducing the spacing in the longitudinal direction between the adjacent slots in the shadow mask; that is, the width of the bridge therebetween, so that the color television picture tubes with excellent brightness and contrast characteristics may be provided without adversely affecting the mechanical strength of the shadow mask.

Method for manufacture of color television picture tubes using rotating

A color picture tube, wherein a set of three electron beams emitted from respective three electron-emitting members of an in-line type electron gun, or from respective three electron guns, is projected through slot-shaped apertures of a shadow mask onto a screen, and sets of each three luminous strips are formed separated from each other and surrounded by light absorbing black film, and the three electron beams selectively energize the luminous strips to emit luminous color images, the length and width of the slots on the shadow mask and those of the phosphor strips having specified correlations in the central part of the picture screen and the shadow mask, and different correlations in the corner parts of the screen and the shadow mask so that color picture reproduction in contrast, brightness and color balance is satisfactory over the entire screen.

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Neyagawa, Japan

Kakuichiro Hosokoshi