Hitachi, Ltd.

Hitachi Displays, Ltd.

Hitachi Display Devices, Ltd.

Satoshi Muto

Masahiro Nishizawa

Noriharu Matsudate

Masaharu Kumada

Ken Hashimoto

Yoichi Ito

Mitsuru Watanabe

Toshifumi Komiya

Reiji Torai

Toshio Suzuki

A cold cathode fluorescent lamp includes a tube having an inner surface coated with a fluorescent film and tubular discharge electrodes disposed at both inner ends of the tube. Each discharge electrode has an opening facing a discharge area and includes a projection in the opening, the area of the projection being reduced by electric discharge.

Cold cathode fluorescent lamp and liquid crystal display device

A correction filter used in the exposure for forming a phosphor screen includes three kinds of correction filters consisting of a grading filter, a monochroic local correction filter and a multi-color local correction filter. With the use of three kinds of correction filters, it is possible to improve the whiteness uniformity which may be degraded due to the wall thickness difference at the center and a peripheral portion of a panel portion of a flat-face-type color cathode ray tube.

Manufacturing method of color cathode ray tube

In an exposure step for forming a phosphor screen of a color cathode ray tube, correction lenses which are arranged between a light source and a panel are used in a state that a common correction lens which is used in common for three colors and three kinds of monochroic correction lenses are combined. The present invention can, in a flat-face-type color cathode ray tube, prevent the generation of the mislanding attributed to the difference in a wall thickness between a center portion and a peripheral portion of a panel thus improving the color purity.

A color cathode ray tube has stress-absorbing hole patterns in skirt portions of its color selection electrode. Each of the stress-absorbing hole patterns is composed of a plurality of columns of rectangular through holes, and the columns are arranged in a lengthwise direction of the skirt portions. Each of the plurality of columns of rectangular through holes is composed of rectangular through holes arranged in a widthwise direction of the skirt portions. The relationships in shape of the rectangular through holes among outermost columns, columns next to the outermost columns, and remaining columns is optimized in the stress-absorbing hole patterns.

Color cathode ray tube

A cathode ray tube has a panel portion with a phosphor layer formed on its inner face, a neck portion accommodating an electron gun , a funnel portion for coupling the panel portion to the neck portion and a color selective electrode assembly having a number of electron beam passing openings arranged opposite to the phosphor layer with a space therebetween. The color selective electrode assembly is installed within the panel portion . An electron beam reflection film of a bismuth oxide thin film R having a bulk density of at least 1 g/cm , e.g., from 1 to 9.3 g/cm , is formed on the face of the color selective electrode assembly 6 against which the electron beams emitted from the electron gun collide. The cathode ray tube is capable of displaying high density and high resolution image.

Method of producing a cathode ray tube

A cathode ray tube has a panel portion,with a phosphor layer,formed on its inner face, a neck portion,accommodating an electron gun,, a funnel portion,for coupling the panel portion,to the neck portion,and a color selective electrode assembly,having a number of electron beam passing openings arranged opposite to the phosphor layer,with a space therebetween. The color selective electrode assembly is installed within the panel portion,. An electron beam reflection film of a bismuth oxide thin film,R having a bulk density of at least from 41 g/cm,, to 9.3 g/cm,, e.g., is formed on the face of the color selective electrode assembly,against which the electron beams,emitted from the electron gun,collide. The cathode ray tube is capable of displaying high density and high resolution image.

Cathode ray tube having bismuth oxide layer on color selective electrode

A cathode ray tube has a panel portion 1 with a phosphor layer 5 formed on its inner face, a neck portion 2 accommodating an electron gun 9, a funnel portion 2 for coupling the panel portion 1 to the neck portion 2 and a color selective electrode assembly 6 having a number of electron beam passing openings arranged opposite to the phosphor layer 5 with a space therebetween. The color selective electrode assembly is installed within the panel portion 1. An electron beam reflection film of a bismuth oxide thin film 6R having a bulk density of from 4 to 9.3 g/cm.sup.3 is formed on the face of the color selective electrode assembly 6 against which the electron beams 14 emitted from the electron gun 9 collide. The cathode ray tube is capable of displaying high density and high resolution image.

Cathode ray tube having reduced doming effect

The color cathode ray tube of this invention improves the purity (color purity) adjustment margin and permits bright display without deteriorating the resolution. At least the black matrix holes 40g, 40b, 40r, forming the phosphor surface or the shadow mask apertures are so arranged that the center-to-center distance between the adjacent holes or apertures corresponding to the pixel phosphors of the same color in a vertical direction is greater by about 10 to 70% than the center-to-center distance in an inclined direction. Further, at least the black matrix holes or the shadow mask apertures are shaped non-circular with their vertical cross-section greater than their horizontal cross-section. With this invention it is possible to provide a color cathode ray tube which has improved brightness and purity (color purity) adjustment margin and a substantially enhanced resolution.

Growing community of inventors

Mobara, Japan

Satoshi Muto