X-ray tube
AssigneeRigaku Corporation
InventorsMasahiro Nonoguchi, Masaru Kuribayashi
Life of this patent
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Abstract
An X-ray tube includes an electron gun in which a Wehnelt electrode is formed with an opening asymmetric about an electron emitter. The electron emitter is an elongate coil filament which is disposed inside the elongate opening of the Wehnelt electrode. The opening has two longer sides positioned asymmetrically about a center-of-width line of the filament. Each of the two longer sides is curved in the same direction as viewed in a direction normal to the front face of the Wehnelt electrode. The two longer sides have curvature radii R1 and R2 different from each other, so that an electron-beam-irradiation region on a target is not curved but becomes almost straight.
Claims7
An X-ray tube including (i) an electron gun having (i-a) a Wehnelt electrode formed with an elongate opening and (i-b) an elongate electron emitter disposed inside the opening and (ii) a target which is irradiated with an electron beam emitted from the electron gun to generate X-rays, wherein
- the opening has two longer sides positioned asymmetrically about a center-of-width line of the electron emitter, and
- each of the two longer sides is curved in a same direction as viewed in a direction normal to a front face of the Wehnelt electrode.
An X-ray tube including (i) an electron gun having (i-a) a Wehnelt electrode formed with an elongate opening and (i-b) an elongate electron emitter disposed inside the opening and (ii) a target which is irradiated with an electron beam emitted from the electron gun to generate X-rays, wherein
- the opening has two longer sides positioned asymmetrically about a center-of-width line of the electron emitter, and
- the two longer sides are curved in opposite directions relative to each other as viewed in a direction which is parallel to a front face of the Wehnelt electrode and yet perpendicular to a longitudinal direction of the opening.
An X-ray tube including (i) an electron gun having (i-a) a Wehnelt electrode formed with an elongate opening and (i-b) an elongate electron emitter disposed inside the opening and (ii) a target which is irradiated with an electron beam emitted from the electron gun to generate X-rays, wherein
- the opening has two longer sides positioned asymmetrically about a center-of-width line of the electron emitter,
- an electron-beam-irradiation region on the target has an elongate shape, and
- each of the two longer sides has a shape consisting of a curved line or a series of plural line segments approaching the curved line so that the electron-beam-irradiation region has a curvature coefficient being not greater than 0.01.
Dependencies are inferred from the claim text.