Kabushiki Kaisha Toshiba

Tokyo Shibaura Denki Kabushiki Kaisha

Other

Takashi Noji

Yoshiharu Obata

Shigeharu Kawamura

Masahiro Sugiyama

Yoshinobu Sekijima

Junichi Takahashi

Hiroshi Aida

Norio Harao

Chikara Konagai

Koichi Nittoh

Junji Taniguchi

Hitoshi Yamada

Yuuichi Murakoshi

Mitsumasa Hiroi

Kazutoshi Tanno

Norio Hapao

Takayoshi Higashi

An object of the present invention is to provide an X-ray image tube which enables acquisition of an image of a proper density by increasing contrast without increasing an irradiation dose of X-rays. The X-rays absorbed or scattered through a subject emit light on an input surface formed in an input window, and the light is further converted into electrons on a photoelectric surface which converts the light into the electrons, accelerated and focused by a focusing electrode, and then guided to an anode side. The electrons guided to the anode side are made visible by a fluorescent substance, and an image of a color is projected on a glass plate with a luminance and a color based on a distribution of the incident X-rays in accordance with the dose of the X-rays.

X-ray image tube, X-ray image tube device and X-ray device

The present invention provides an X-ray image detector ( ) which can reduce the size of a whole apparatus associated with an X-ray imaging tube, reduce noise components of an output X-ray image even if an incident X-ray is very weak, and provide a distortion-free visible image or electric image. The X-ray image detector ( ) comprises a vacuum container having an input fluorescent screen outputting fluorescent light, a photoelectric screen converting the fluorescent light which is output from the input fluorescent screen to a photoelectron, and an output fluorescent screen outputting a visible light image with the obtained electron, a plurality of image pick-up elements ( ) arranged such that partially overlapped areas are outside an image taking area and taking the visible light image in a divided way, image processing circuits ( ) so arranged as to correspond to the image pick-up elements and trimming a taken video signal, an output image processing circuit ( ) obtaining a composed image and a display device ( ) displaying it as one signal.

X-ray image detector

The object of the present invention is to provide a radioactive-ray image tube having less deformations, such as the twist of an input substrate, less aberration over the entire regions of an output image, excellent resolution and good brightness uniformity and contrast characteristics. This radioactive-ray image tube,comprises an input window,formed on one side surface of a vacuum vessel,and allowing radioactive-rays to enter the vacuum vessel,, an input screen,for converting the radioactive-rays incident on the input window,into a fluorescent image or a photoelectric image, and an input substrate,holding the input screen,is characterized in that the input substrate,comprises of a clad material,having an aluminum alloy material,on the radioactive-ray incidence side and a pure aluminum material,on the input screen,side provided integrally with each other.

Radioactive-ray image tube having input member formed of a clad material

An X-ray image tube according to the present invention has a whole evacuated envelope comprising an metallic input window through which X-rays pass, a metallic frame to which the metallic input window is welded, a hollow cylinder portion, an output window, etc., and the metallic input window and the metallic frame are hermetically welded to each other by ultrasonic welding. By means of such a construction, an X-ray image tube which can suppress occurrence of distortion of an electronic lens formed in the evacuated envelope, and a manufacturing method thereof is realized.

X-ray image tube and manufacture thereof

The present invention assures a satisfactory adhesiveness of an input screen,of an X-ray image intensifier, high resolution of an output image and brightness uniformity as required, by configuring an aluminum or aluminum alloy substrate,so to have a concave surface with minute irregularities of the substrate material removed by burnishing, excepting gentle irregularities,without directivity which are caused by pressing. The gentle irregularities,of the substrate,preferably have an average length L in a range of 50 &mgr;m to 300 &mgr;m between the neighboring bottoms and an average height H in a range of 0.3 &mgr;m to 4.0 &mgr;m from peaks to bottoms. The invention improves resolution with light on the substrate surface suppressed from being scattered, and decreases image noises which are caused by the minute irregularities.

X-ray image intensifier and method for manufacturing thereof

An X-ray image intensifier includes an input surface and an output surface facing the input surface. The input surface has a base and a phosphor layer formed on the base and having a predetermined effective radius. The phosphor layer includes a thickest portion which has a thickness about 105 to 115% of a thickness of a center of the layer and is located in a region spaced from the center toward the periphery of the layer by a distance about 60 to 80% of the effective radius. The phosphor layer is formed so that the thickness is gradually increased from the center to the thickest portion and a region between the thickest portion and the periphery of the layer has a thickness about 50 to 100% of the thickness of the thickest portion.

X-ray image intensifier with phosphor layer of varying thickness

A phosphor screen constructed by forming a phosphor layer on one side of an optical fiber plate consisting of a large number of bundled single optical fibers, each of which fibers comprises a cylindrical core and a clad surrounding the curved surface of the fiber core. At least that side of the respective fiber cores which faces the phosphor layer is removed, to provide a depression. Sufficiently large spaces are formed between the fiber cores and phosphor layer, to prevent both members from being brought into optical contact with each other.

Fiber optic phosphor screen and a method of manufacturing the same

An X-ray image intensifier apparatus consists of an X-ray image intensifier having an input window and an input screen opposing the input window, and a container for storing the X-ray image intensifier, and has a good contrast property. An X-ray shielding member comprising a resin in which a particulate material having X-ray shielding and absorbing effects is dispersed is provided on a peripheral portion of an input side of the X-ray image intensifier apparatus.

X-ray image intensifier

A phosphor screen which has an optical fiber plate formed of a number of bundled single optical fibers, each of which fibers consists essentially of a cylindrical core and a clad surrounding the curved peripheral wall of the core and a phosphor layer formed on one surface of the optical fiber plate, characterized in that the cylindrical core on the other surface of the optical fiber plate is removed, to provide a depression of a depth of at least 1 .mu.m, thereby producing an image having high contrast.

Method of manufacturing a phosphor screen

High resolution output structure for an image tube which minimizes

An input phosphor screen includes a substrate having a substantially smooth surface, and first and second phosphor layers both vapor-deposited sequentially on the substrate. The first layer is made of phosphor crystal particles having a mean diameter of 15 .mu.m or less. The second layer has a thickness ten or more times that of the first layer and is made of individual columnar crystals of alkali halide grown vertically on the crystal particles, standing close together with fine spaces therebetween. A third layer is preferably deposited on the second layer as a continuous film. These three layers can be deposited by evaporating a phosphor material or materials at a prescribed temperature and at a predetermined degree of vacuum.

Method of manufacturing a radiation excited input phosphor screen

An input screen and method of forming one for an image intensifier tube including a substrate in which a plurality of crystal grains of aluminum or aluminum alloy are formed in a plane with the crystal grains having non-directional shapes in the plane. The crystal grains are formed by heating in a vacuum or non-oxidizing atmosphere at a temperature between 450.degree. C. and 650.degree. C. The oxidized layer is next removed by an etchant, and a phosphor layer formed on the crystal grains by vapor-deposit.

Growing community of inventors

Odawara, Japan

Takashi Noji