COLLIMATOR ASSEMBLY AND RAY DETECTION APPARATUS

• US 20200135356A1
• Filed: 10/30/2019
• Published: 04/30/2020
• Est. Priority Date: 10/31/2018
• Status: Active Grant

• Current Assignee: Nuctech Company Limited (Tsinghua Tongfang Co., Ltd.)
• Original Assignee: Nuctech Company Limited (Tsinghua Tongfang Co., Ltd.)
• Inventors: LI, Hanping, HU, Yuecheng, ZHAO, Kun
• Granted Patent: US 11,295,871 B2
• Time in Patent Office: Days
• CPC Class Codes: A61B 6/06 Diaphragms
• CPC Class Codes: G01N 2223/316 collimators
• CPC Class Codes: G01N 2223/32 adjustments of elements during operation
• CPC Class Codes: G01T 1/16 Measuring radiation intensity G01T1/29 takes precedence ; self-powered detectors G01T3/006; using an ionisation chamber filled with a liquid or solid, e.g. frozen liquid, dielectric G01T3/008
• CPC Class Codes: G21K 1/025 using multiple collimators, e.g. Bucky screens; other devices for eliminating undesired or dispersed radiation
• CPC Class Codes: G21K 1/04 using variable diaphragms, shutters, choppers

Abstract

The disclosure provides a collimator assembly, comprising at least at least two collimators configured to be moveable relative to each other such that the collimator assembly is switchable between at least two collimation modes; in respective collimation modes, the at least two collimators are superposed with each other in a thickness direction of the collimator assembly, such that the collimator assembly presents different combined patterns for collimating and shielding rays incident onto the collimator assembly and that the collimator assembly has corresponding ray shielding thickness for effectively shielding rays.

Claims

1. A collimator assembly, comprising at least a first collimator and a second collimator, the first collimator and the second collimator being configured to be moveable relative to each other such that the collimator assembly is switchable at least between a first collimation mode and a second collimation mode,

in the first collimation mode, the first collimator and the second collimator are superposed with each other in a thickness direction of the collimator assembly, such that the collimator assembly has a first combined pattern for collimating and shielding rays incident onto the collimator assembly and such that a portion of the collimator assembly for shielding the rays has a first ray shielding thickness,

in the second collimation mode, the first collimator and the second collimator are superposed with each other in the thickness direction of the collimator assembly, such that the collimator assembly has a second combined pattern for collimating and shielding rays incident onto the collimator assembly and such that another portion of the collimator assembly for shielding the rays has a second ray shielding thickness, and

the first combined pattern is different from the second combined pattern, and the first ray shielding thickness is different from the second ray shielding thickness.

2. The collimator assembly according to claim 1, wherein,

the first collimator comprises a first pattern for collimating and shielding rays incident onto the first collimator;

and

the second collimator comprises a second pattern for collimating and shielding rays incident onto the second collimator, and different combinations of the second pattern and the first pattern in the first collimation mode and the second collimation mode defines the first combined pattern and the second combined pattern respectively.

3. The collimator assembly according to claim 2, wherein the second pattern is different from the first pattern.

4. The collimator assembly according to claim 2, wherein the first pattern and the second pattern are complementary to each other.

5. The collimator assembly according to claim 2, wherein,

the first pattern and the second pattern are configured such that in one of the first collimation mode and the second collimation mode, one of the first pattern and the second pattern is at least partly embedded into the other of the first pattern and the second pattern.

6. The collimator assembly according to claim 2, wherein one of the first combined pattern and the second combined pattern is different from each of the first pattern and the second pattern.

7. The collimator assembly according to claim 2, wherein at least one of the first pattern and the second pattern includes a MURA coded pattern.

8. The collimator assembly according to claim 2, wherein, one of the first combined pattern and the second combined pattern comprises a MURA coded pattern, and the other of the first combined pattern and the second combined pattern comprises a single-pinhole pattern or a multi-pinhole pattern.

9. The collimator assembly according to claim 2, wherein,

a part of the first pattern for shielding the rays has a first thickness, while a part of the second pattern for shielding the rays has a second thickness,

one of the first ray shielding thickness and the second ray shielding thickness is equal to a sum of the first thickness and the second thickness, and

the other of the first ray shielding thickness and the second ray shielding thickness is equal to, at a first position of the collimator assembly, the first thickness, and is equal to, at a second position of the collimator assembly, the second thickness.

10. The collimator assembly according to claim 2, wherein,

the first pattern of the first collimator comprises:

a plurality of first ray transmission regions configured to allow rays incident onto the first collimator to pass through the first collimator; and

a plurality of first ray shielding regions delimiting the plurality of first ray transmission regions and configured to block the rays incident onto the first collimator from passing through the first collimator; and

the second pattern of the second collimator comprises;

a plurality of second ray transmission regions configured to allow rays incident onto the second collimator to pass through the second collimator; and

a plurality of second ray shielding regions arranged to at least surround the plurality of second ray transmission regions and configured to block the rays incident onto the second collimator from passing through the second collimator.

11. The collimator assembly according to claim 10, wherein the plurality of second ray shielding regions are configured to be at least partly embeddable into the plurality of second ray transmission regions, in one of the first collimation mode and the second collimation mode.

12. The collimator assembly according to claim 10, wherein,

the first collimator comprises a first plate (111) defining the first pattern, the plurality of first ray transmission regions comprise a plurality of opening holes extending through the first plate, and the plurality of first ray shielding regions comprise parts of the first plate made of a first ray shielding material;

and/or

the second collimator comprises a second plate (121) and a mesh patterned structure, the second plate is made of a ray transmission material, the mesh patterned structure comprises a plurality of protrusions extending from one surface of the second plate toward the first collimator and a plurality of mesh holes delimited by the plurality of protrusions, the plurality of protrusions are made of a second ray shielding material, and the mesh patterned structure is disposed on a surface of the second plate so as to define, together with the second plate, the second pattern, such that the plurality of protrusions form the plurality of second ray shielding regions, and parts of the second plate corresponding to the plurality of mesh holes define the plurality of second ray transmission regions.

13. The collimator assembly according to claim 1, wherein,

the first collimator and the second collimator are configured to be moveable with respect to each other in the thickness direction and be rotatable with respect to each other about an axis extending in the thickness direction, such that the collimator assembly is switchable between the first collimation mode and the second collimation mode.

14. The collimator assembly according to claim 13, wherein,

the second collimator is configured to abut against a surface of the first collimator in the second collimation mode, and is rotatable with respect to the first collimator about the axis by an angle and is moveable toward the first collimator in the thickness direction so as to be at least partly embedded into the first collimator, thereby switching from the second collimation mode to the first collimation mode.

15. A ray detection apparatus, comprising:

the collimator assembly of claim 1, the collimator assembly being configured for collimating and shielding rays from a ray source; and

a detector configured to receive the collimated rays from the collimator assembly and to generate a signal indicative of the received rays.