Radiation generating tube, and radiation generating apparatus and radiation imaging system using the same

Patent metadata

Field	Value
Publication number	US-9401259-B2
Application number	US-201414293493-A
Country	US
Kind code	B2
Filing date	Jun 2, 2014
Priority date	Jun 12, 2013
Publication date	Jul 26, 2016
Grant date	Jul 26, 2016

Abstract

Provided is a radiation generating tube in which an insulating tube is prevented from being damaged by heat generation of a target or an electron emitting source during drive. Extending portions extending along an outer periphery of an insulating tube are provided to a cathode and an anode, respectively, and the insulating tube is joined to the extending portions to enhance the strength of joint portions. At the same time, the insulating tube can be deformed easily by setting a tube wall thickness of the insulating tube at a central portion in a longitudinal direction to be smaller than a tube wall thickness of an opening end, and thus the concentration of thermal stress on the joint portions caused by an increase in temperature of the cathode and the anode is alleviated.

First claim

What is claimed is:

1. An X-ray generating tube, comprising:
an insulating tube having a tube body extending along a longitudinal direction and a pair of ends;
a cathode secured to one of the pair of ends and including an electron emitting source, the cathode having a peripheral portion joined to an end face of the one of the pair of ends; and
an anode secured to the other of the pair of ends and including a target, the anode having a peripheral portion joined to an end face of the other of the pair of ends,
wherein at least any one of the cathode and the anode includes a tubular extending portion extending along the longitudinal direction,
wherein the tubular extending portion has a higher coefficient of thermal expansion than the insulating tube,
wherein the tubular extending portion is secured to the insulating tube via a tubular joint portion, and
wherein the insulating tube has a thinner tube wall region having a thinner tube wall than the tubular joint portion of the insulating tube, said thinner tube wall region being distant from the tubular joint portion along the longitudinal direction.

2. The X-ray generating tube according to claim 1 , wherein the thinner region is located in an intermediate portion in a longitudinal direction of the insulating tube.

3. The X-ray generating tube according to claim 1 , wherein a tube wall thickness of the insulating tube at a central portion in the longitudinal direction is smaller than the tube wall thickness of the tubular joint portion of the insulating tube.

4. The X-ray generating tube according to claim 1 , wherein, in the longitudinal direction of the insulating tube, the thinner tube wall region is separated from an end of the tubular extending portion by at least a thickness of the tubular joint portion of the insulating tube.

5. The X-ray generating tube according to claim 1 , wherein the tube wall thickness becomes smaller continuously from a thicker tube wall region of the insulating tube to the thinner tube wall region of the insulating tube.

6. The X-ray generating tube according to claim 1 , wherein the tubular extending portion is joined to the outer periphery of the insulating tube.

7. The X-ray generating tube according to claim 1 , wherein the tubular extending portion is joined to the inner periphery of the insulating tube.

8. The X-ray generating tube according to claim 1 , wherein the tubular extending portion protrudes from the at least any one of the cathode and the anode toward the other of the cathode and the anode.

9. The X-ray generating tube according to claim 1 , wherein the cathode and the anode each include the tubular extending portion.

10. The X-ray generating tube according to claim 1 , wherein a length of the thinner tube wall region of the insulating tube is 40% or more of a length of the insulating tube.

11. The X-ray generating tube according to claim 1 , wherein the tube wall thickness of the insulating tube in the thinner tube wall region is 10% to 80% with respect to a tube wall thickness of the insulating tube in a thicker tube wall region thereof.

12. The X-ray generating tube according to claim 1 , wherein the insulating tube is made of one of ceramics and glass, and the cathode and the anode are made of a metal.

13. The X-ray generating tube according to claim 12 , wherein the metal comprises any one of a NiCuFeMn alloy, a NiCrFe-based alloy, a FeNiCo alloy, and stainless steel.

14. The X-ray generating tube according to claim 1 , wherein the X-ray generating tube comprises a transmission type X-ray generating tube.

15. An X-ray generating apparatus, comprising:
the X-ray generating tube according to claim 1 ; and
a storage container accommodating the X-ray generating tube and having an emission window for extracting a radiation generated from the X-ray generating tube,
wherein a space left inside the storage container is filled with an insulating fluid.

16. The X-ray generating apparatus according to claim 15 , further comprising a movable diaphragm unit for adjusting an X-ray field of the X-ray emitted from the emission window of the storage container.

17. A radiography system, comprising:
the X-ray generating apparatus according to claim 15 ;
an X-ray detecting apparatus for detecting an X-ray emitted from the X-ray generating apparatus and transmitted through a subject to be investigated; and
a control apparatus for controlling the X-ray generating apparatus and the X-ray detecting apparatus in a coordinated manner.

18. The X-ray generating tube according to claim 1 , wherein the thinner tube wall region is provided in the insulating tube configured to relax a thermal stress due to a difference in the coefficient of thermal expansion between the insulating tube and the tubular extending portion.

Assignees

• Canon Kk

Inventors

• Ukiyo Noritaka
• Sato Yasue
• Yanagisawa Yoshihiro
• Sando Kazuhiro

Classifications

• H05G1/04

  Mounting the X-ray tube within a closed housing · CPC title

• H01J19/42

  Mounting, supporting, spacing, or insulating of electrodes or of electrode assemblies · CPC title

• H01J2235/166

  against electromagnetic radiation · CPC title

• H01J2237/16

  Vessels · CPC title

• H01J2229/4827

  Electrodes formed on surface of common cylindrical support · CPC title