Kabushiki Kaisha Toshiba

Fumihito Suzuki

Shigeru Sugawara

Takahiro Hasegawa

Junichi Kimiya

Fumio Miyanaga

Katsumi Yaha

A coating apparatus for forming a high-resistance film on the inner surface of the neck of the funnel of a cathode ray tube has a nozzle that can be inserted into the neck. The nozzle, which is provided for applying a material liquid to the inner surface of the neck, has a jet hole inclined toward the direction of gravity. The material liquid applied through the jet hole thus inclined scarcely flows upwardly on the inner surface of the neck. The liquid therefore forms a high-resistance film having a uniform thickness on the inner surface of the neck of the funnel. Having a uniform thickness, the high-resistance film inhibits the charge-up of the neck potential, reducing the convergence drift caused by the charge-up of the neck potential.

Method of manufacturing a cathode ray tube and apparatus manufacturing the same

A cathode ray tube according to the invention comprises an internal conductive film arranged on the inner wall surface of the envelope and extending from the funnel section to the neck section and a high resistance conductive film arranged in the neck section to contact the internal conductive film at an end of thereof and surround part of the electron gun assembly. The high resistance conductive film shows an electric resistance higher than that of the internal conductive film. Additionally, in a cathode ray tube according to the invention, the electric resistance of the high resistance conductive film in terms of per unit length along the axis of the tube is lower at and near the contact region held in contact with the corresponding end of the internal conductive film than at and near the opposite end of the high resistance conductive film.

Cathode ray tube having high resistance film on the inner wall of the neck

A high-resistance film having a plurality of pores and a resistance of 10.sup.10 to 10.sup.14 .OMEGA. is formed on the inner wall of the neck from a position where the high-resistance film contacts the inner conductive film to at least part of the inner wall surrounding at least the space between the grid farthest from a cathode to the grid second farthest from the cathode.

Color cathode ray tube with high resistance film in the electron gun

Disclosed is a color cathode ray tube including an in-line electron gun, in which a high-resistance film whose resistance R at T.degree.C. has a resistance-temperature characteristic represented by d(Log R(T))/dT.gtoreq.-0.01 at least at a temperature ranging from 20.degree. C. to 40.degree. C. and is approximately 5.times.10.sup.13 .OMEGA. or less at about 25.degree. C. is formed on the inner wall of the neck.

Color cathode ray tube

The electron gun assembly for cathode ray tube, has the structure in which the first, second and third grids are arranged in the traveling direction of an electron beam emitted from cathodes, and so is the fourth grid to which a anode voltage is applied, a suppressing ring is provided to be adjacent to the second and third grids, a dynamic focus voltage which is varied in synchronism with the deflection of the electron beam is applied to the first and third grids, and the first and second grids are connected to each other by means of the resistor provided adjacent thereto.

Growing community of inventors

Fukaya, Japan

Fumihito Suzuki