Radiation generating tube and radiation imaging apparatus using the same

Patent metadata

Field	Value
Publication number	US-9251995-B2
Application number	US-201214127647-A
Country	US
Kind code	B2
Filing date	Jul 17, 2012
Priority date	Aug 31, 2011
Publication date	Feb 2, 2016
Grant date	Feb 2, 2016

Abstract

A radiation generating tube 1 includes: an electron emitting source 3; a target 9 spaced from the electron emitting source 3, for generating radiation 11 responsive to irradiation with an electron beam from the electron emitting source 3; and a tubular shielding member 10 having an electron passing hole 8, wherein the electron passing hole 8 has an electron incident aperture at one end thereof and has a target supporting surface 9 b supporting the target 9 at the other end thereof, wherein the target supporting surface 9 b is connected through a brazing filler 14 to a periphery of a surface of the target at a side on which the electron is incident, and an opening size of the other end of the electron passing hole 8 is larger than an opening size of the electron incident aperture at the one end thereof.

First claim

The invention claimed is:

1. A radiation generating tube comprising:
a cathode having an electron emitting source;
an anode having a target spaced from said electron emitting source, for generating radiation responsive to an irradiation with an electron emitted from the electron source; and
a tubular shielding member having an electron passing hole which has an electron incident aperture at one end thereof and has a target supporting surface supporting said target at the other end thereof,
wherein said target supporting surface is connected through a brazing filler to a periphery of a surface of said target at a side on which the electron is incident, and
wherein said anode has an annular recess located between said target supporting surface and said electron passing hole in said tubular shielding member.

2. The radiation generating tube according to claim 1 , wherein said annular recess has, in a cross-section, a rectangular shape or inclined slope shape.

3. The radiation generating tube according to claim 2 , wherein said annular recess is shaped to extend a distance along a surface of said shielding member from said target supporting surface to an inner surface of said electron passing hole.

4. The radiation generating tube according to claim 1 , wherein said target contains a target metal of atomic number 24 or more.

5. The radiation generating tube according to claim 4 , wherein said target metal includes any one of: tungsten, molybdenum, chromium, copper, cobalt, iron, and rhodium, or any alloy thereof.

6. The radiation generating tube according to claim 1 , wherein said target is provided with a transmitting substrate containing, as a main ingredient, diamond, silicon nitride, or aluminum nitride.

7. The radiation generating tube according to claim 6 , wherein said transmitting substrate is a diamond substrate containing diamond as a main ingredient.

8. The radiation generating tube according to claim 6 , wherein said target metal forms a target layer on said transmitting substrate, and said target layer is arranged on a side of said target facing said electron emitting source.

9. The radiation generating tube according to claim 6 , wherein said target supporting surface supports at least said transmitting substrate.

10. The radiation generating tube according to claim 8 , wherein said transmitting substrate has a coated surface on which said target layer is arranged, and wherein said transmitting substrate has a thickness in a direction normal to said coated surface in a range from 0.3 mm to 2 mm.

11. The radiation generating tube according to claim 8 , wherein said target layer has a thickness in a normal direction thereof in a range from 1 μm to 15 μm .

12. The radiation generating tube according to claim 1 , wherein said brazing filler is a Cr—V series brazing material, a Ti—Ta—Mo series brazing material, a Ti—V—Cr—Al series brazing material, a Ti—Cr series brazing material, a Ti—Zr—Be series brazing material, a Zr—Nb—Be series brazing material, an Au—Cu series brazing material, a nickel series brazing material, a brass series brazing material, a silver brazing material, or a palladium brazing material.

13. The radiation generating tube according to claim 1 , wherein said tubular shielding member has a backward shielding portion for shielding at least a part of the radiation emitted from said target toward said electron source.

14. The radiation generating tube according to claim 1 , wherein said tubular shielding member extends toward a surface of said target opposite to a surface of said target irradiated with the electron, and has a forward shielding portion for shielding at least a part of the radiation emitted from said target.

15. A radiation generating apparatus comprising:
the radiation generating tube according to claim 1 ;
a power source for driving said radiation generating tube; and
a container holding said radiation generating tube.

16. A radiation imaging apparatus comprising:
a radiation generating apparatus according to claim 15 ; and
a radiation detector for detecting the radiation emitted from said radiation generating apparatus and transmitted through an object.

17. The radiation generating tube according to claim 1 , wherein said annular recess surrounds said electron passing hole in said anode.

18. The radiation generating tube according to claim 1 , wherein said supporting surface, said annular recess and said electron passing hole are aligned in this order along a radial direction of said target such that brazing filler is prevented from flowing from said supporting surface to said electron passing hole.

19. An X-ray generating tube comprising:
a cathode including an electron emitting source emitting an electron; and
an anode including
a target generating an X-ray upon being irradiation by an electron emitted from said electron emitting source, and
a tubular shielding member having an annular secured portion, and having a tubular inner wall defining an electron passing hole,

wherein said target is secured to said annular secured portion via a bonding member annularly, and
wherein said anode has an annular recess located between said annular secured portion and said tubular inner wall in said tubular shielding member.

20. The X-ray generating tube according to claim 19 , wherein said annular recess surrounds said electron passing hole.

21. The X-ray generating tube according to claim 19 , wherein said annular secured portion, said annular recess and said tubular inner wall are aligned in that order along a radial direction of said target such that said bonding member is prevented from flowing from said secured portion to said tubular inner wall.

22. The X-ray generating tube according to claim 19 , wherein said annular secured portion, said annular recess and said tubular inner wall are aligned in this order along a radial direction of said target such that said annular recess prevents the electron beam from directly colliding with any of said bonding member which has flowed out from said secured portion.

Assignees

• Ogura Takao
• Ueda Kazuyuki
• Sato Yasue
• Nomura Ichiro
• Canon Kk

Inventors

• Ogura Takao
• Ueda Kazuyuki
• Sato Yasue
• Nomura Ichiro

Classifications

• H01J2235/186

  Electricity · mapped topic

• H01J2235/166

  against electromagnetic radiation · CPC title

• H01J35/16

  Vessels; Containers; Shields associated therewith · CPC title

• H01J2235/087

  Electricity · mapped topic

• H01J35/08

  Anodes; Anti cathodes · CPC title