Hitachi, Ltd.

Hitachi Device Engineering Co., Ltd.

Hisashi Nose

Hidehiro Koumura

Takao Nakamura

Mutsumi Maehara

Tsuyoshi Iwata

Tomoki Nakamura

Takao Kawamura

Kentaro Oku

Eisuke Inoue

Kunio Ishiyama

Shigemi Hirasawa

Hiroshi Ito

Norikazu Uchiyama

Toshio Tojo

Toshio Uyama

Kenji Kawamata

Zenjiro Kanzaki

Toshikazu Igarashi

In a cathode ray tube of the present invention, the shape of an outer wall opening and the shape of an inner wall opening in a direction perpendicular to a tube axis within a range which extends 35 mm to the panel portion side and 20 mm to the neck portion side from a reference line set in a deflection yoke mounting region of a funnel portion are respectively formed in an approximately rectangular shape and an approximately pin-cushion shape, and the shape of the inner wall opening of deflection yoke mounting region of the funnel portion in a direction perpendicular to a tube axis direction has a radius of curvature Rc at respective corners, and the difference between a first straight line V and H which connects neighboring bottom portions of the corners and a second straight line V and H which is in contact with a central point of the inner wall between the neighboring corner portions and is disposed parallel to the first straight line is set to 2.0 mm at maximum provided that the direction toward the tube axis is taken as &plus;.

Cathode ray tube

A color cathode ray tube includes a vacuum envelope comprised of a neck portion having a circular cross section and a funnel portion having a deflection yoke mounting region of pyramidal shape at a side which is connected to said neck portion. In this color cathode ray tube, an inflection edge in which an inner surface angle changes from an inner wall of the deflection yoke mounting region to a panel portion side inner wall of said funnel portion is formed on an inner surface of a funnel portion at a panel portion side terminal end of the deflection yoke mounting region, and an angle made by a straight line which passes through an endmost face of the inflection edge and is perpendicular to the tube axis and a tangent line at the endmost face is within 5&deg;-11&deg;. The pyramidal deflection yoke mounting region has the inner wall opening perpendicular to the tube axis direction formed in a pin cushion shape and recesses having a curvature are formed at respective corners. The distance between a first straight line which connects bottom portions of neighboring recesses of the corner portions and a second straight line which is in contact with a central point of an inner wall between the neighboring corners and is parallel with the first straight line is not more than 2.0 mm or preferably not more than 0.1 mm, provided that said tube axis direction is taken as &plus;.

A color cathode ray tube including a shadow mask assembly and an inner shield provided for the shadow mask assembly which are disposed within the tube. The shadow mask assembly includes a substantially rectangular shadow mask, a substantially rectangular mask frame, and a spring for mounting the shadow mask assembly in the panel of the cathode ray tube. The shadow mask has a curved surface having electron beam passing holes and a skirt folded from the margin of the curved surface and extending in a tube axis direction. At least one of the major and minor sides of the substantially rectangular shadow mask has a curvature convex to the tube axis with corners thereof being round and at least one of the major and minor sides of the substantially rectangular mask frame is linear or has a curvature concave to the tube axis with corners thereof being round.

Color cathode ray tube with shadow mask and mask frame having round corners

A color cathode ray tube comprises a vacuum vessel including a panel portion having a phosphor screen on its inner face, a neck portion and a funnel portion joining the neck portion and the panel portion. An inline electron gun is disposed inside of the neck portion and includes a main lens and cathode producing a center electron beam and two side electron beams. A deflection yoke for deflecting the electron beams and a pair of 2-pole ring magnets for adjusting electron beam trajectory are disposed around the neck portion. The 2-pole ring magnets have a magnetic flux density distribution at a circle which is concentric with the ring magnets, wherein the radius of the circle corresponds to the distance between adjacent electron beams at the main lens. The ratio of the amplitude of the flux density in the radial component compared to the amplitude of the flux density in the circumferential component is 0.86 to 1.38 on the circle.

Color cathode ray tube having adjustment magnet assembly at neck portion

A color cathode ray tube comprises a vacuum envelope in which there is mounted a shadow mask having a curved surface having a plurality of electron beam passing holes and a skirt extending downward from the margin of the curved surface. The shadow mask is supported by a mask frame having a substantially rectangular side wall. A shadow mask assembly constituted by fitting and securing the skirt into the side wall is set in the panel of the envelope, and the skirt is fitted and secured into the side wall by curving the middles of two or four facing sides of the skirt inward. Thereby, it is possible to provide a color cathode ray tube having the shadow mask assembly capable of obtaining a superior magnetic shielding characteristic by enlarging the effective region of the curved surface of the shadow mask.

Color cathode ray tube

A cathode ray tube has a vacuum envelope formed of a panel portion supporting a phosphor film on an inner surface thereof, a neck housing an electron gun, a funnel joining the panel and the neck, and a stem sealing an open end of the neck and mounting the electron gun via a plurality of pins extending through the stem. The inside diameters at the open end sealed by the stem and vicinities thereof become gradually larger toward the open end sealed by the stem, or retain at least a value substantially equal to an inside diameter of a major portion of the neck.

Cathode ray tube having a small-diameter neck and method of manufacture thereof

A cathode ray tube has a vacuum envelope including a panel portion having a phosphor screen, a neck portion having a stem fused and sealed to one end thereof, and a funnel portion for connecting the other end of the neck portion and the panel portion. The stem has stem pins annularly arrayed, sealed thereto and extending there-through for supporting an electron gun in the neck portion, and a stem mound is raised and formed integrally with the stem around a base of each of the stem pins on an electron-gun-supporting side thereof. The stem is provided with a raised outer circular edge or a flat outer circular edge. A first distance R,is defined as a distance from a center axis of the neck portion to an inner wall in a region of the neck portion facing a major portion of the electron gun, and a second distance R,is defined as a distance from the center axis to an outside edge of the stem mound as measured at half an axial height of the stem mound. The first distance R,and the second distance R,satisfy a relationship, 0<R,R,<2.1 mm.

Narrow-neck CRT having a large stem pin circle

A color cathode ray tube has a vacuum vessel including a panel portion having a phosphor screen on its inner face, a neck portion and a funnel portion jointing the neck portion and the panel portion; an electron gun assembly including an electrostatic main lens disposed in the neck portion; a deflection yoke arranged around the neck side of the funnel portion for deflecting three in-line arranged electron beams emitted from the electron gun assembly to the phosphor screen; and a 2-pole ring magnet arranged around the neck portion for adjusting the trajectories of the electron beams. The 2-pole ring magnet is arranged to have its center closer to the phosphor screen than is the center of the electrostatic main lens of the electron gun assembly. The value, as calculated by dividing the value of the radial component amplitude of the magnetic field distribution of the 2-pole ring magnet on the circumference of a circle having a radius of the s-size, by the value of the circumferential component amplitude, is 0.86 to 1.38, and preferably 0.955 to 1.275.

Color cathode ray tube having adjustment magnet assembly at the neck portion of the tube

A cathode ray tube has a vacuum envelope including a panel portion having a phosphor screen, a neck portion having a stem fused and sealed to one end thereof, and a funnel portion for connecting the other end of the neck portion and the panel portion. The stem includes plural stem pins annularly arrayed, sealed thereto and extending therethrough for supporting an electron gun in the neck portion. An outside diameter of the neck portion in a region thereof facing a major portion of the electron gun is not more than 29.1 mm. A stem mound is raised and formed integrally with the stem around a base of each of the stem pins on an electron-gun-supporting side thereof. A first distance R1 and a second distance R2 satisfy a relationship, 0&lt;R1-R2&lt;2.1 mm, where the first distance R1 is a distance from the center axis of the neck portion to an inner wall in the region of the neck portion facing the major portion of the electron gun and the second distance R2 is a distance from the center axis to an outside edge of the stem mound as measured at half an axial height of the stem mound. The number of stem pins can be ten and the plural stem pins can include two stem pins for applying focus voltages to two focus electrodes of the electron gun.

A cathode ray tube includes a panel portion having a phosphor screen, a neck portion having a stem fused and sealed to one end thereof, the stem having a plurality of stem pins annularly arrayed, sealed thereto and extending therethrough for supporting an electron gun in the neck portion and a funnel portion for connecting the other end of the neck and panel portions. A stem mound is raised and formed integrally with the stem around a base of each of the stem pins on an electron-gun-supporting side thereof. A first R1 is defined as a distance from a center axis of portion to an inner wall in a region of the neck portion facing a major portion of the electron gun, a second distance R2 is defined as a distance from the center axis tide edge of the stem mound, measured at half an axis of the stem mound, the first distance R1 and the second distance R2 satisfy a relationship, 0&lt;R1-R2&lt;2.1 mm. A wall thickness of a region of the neck portion in the vicinity of the fused and sealed regions of the neck portion and the stem is smaller than a wall thickness of a region of the neck portion facing the major portion of the electron gun.

A cathode ray tube includes a vacuum envelope formed of a panel portion having a phosphor screen on its inner surface and suspending a shadow mask therein, a neck portion having a stem sealed to one end thereof and a funnel portion for connecting the other end of the neck portion and the panel-portion. The stem has a plurality of stem pins annularly arrayed, sealed thereto and extending therethrough for supporting an electron gun in the neck portion. A stem mound is raised and formed integrally with the stem around a base of each of stem pins on a electron-gun-supporting side thereof. A first distance R1 is defined as a distance from a center axis of the neck portion to an inner wall in a region of the neck portion facing a major portion of the electron gun, a second distance R2 is defined as a distance from the center axis to an outside edge of the stem mound, measured at half an axial height of said stem mound, and a third distance is defined as a distance from an inner wall to the center axis. The third distance is not smaller than the first distance R1 at least in a region of the neck portion facing the stem mounds except in the vicinity of fused and sealed regions of the neck portion and the stem, and the first R1 distance and the second distance R2 satisfy a relationship, 0&lt;R1-R2&lt;2.1 mm.

Cathode ray tube having a small-diameter neck and method of manufacture

In a cathode ray tube having an antistatic film 6 stuck to the front surface of a panel section 1 and a conductive tape 7 for grounding the end portion of the antistatic film 6 to the earth, a silicone adhesive 8 containing a conductive filler having an excellent close contact adhesion to silicon dioxide (SiO.sub.2) is interposed in at least a part of an close contact adhesion portion where the conductive tape 7 is stuck to the antistatic film 6. Thanks to the interposition of the conductive filler containing silicone adhesive 8, the resistances between the antistatic film 6 and the conductive tape 7 and between the silicone adhesive 8 and the conductive tape 7 can be lowered and sputtering which may be caused by the high voltage induced in the antistatic film 6 is prevented, so that the breakage of the antistatic film 6 can be prevented at the close contact adhesion portion.

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Kawasaki, Japan

Hisashi Nose