Radiation imaging apparatus, driving method for the same, and non-transitory computer-readable medium

Patent metadata

Field	Value
Publication number	US-9869774-B2
Application number	US-201514741565-A
Country	US
Kind code	B2
Filing date	Jun 17, 2015
Priority date	Jun 25, 2014
Publication date	Jan 16, 2018
Grant date	Jan 16, 2018

Abstract

A radiation imaging apparatus, comprising a plurality of sensors and a driving unit, each sensor including a detection element, a sampling unit and a reset unit, wherein the driving unit performs an operation of causing the reset unit to initialize the detection element, an operation of causing the sampling unit to sample a signal from the detection element in accordance with radiation irradiation started after the operation of initializing, and an operation of outputting a signal sampled by the operation of sampling, and wherein the driving unit changes, in accordance with a frame rate, a timing of the operation of outputting while maintaining constant a time from the operation of initializing to the operation of sampling.

First claim

What is claimed is:

1. A radiation imaging apparatus comprising a plurality of sensors and a driving unit configured to drive the plurality of sensors, each of the plurality of sensors including a detection element configured to detect radiation, a sampling unit configured to sample a signal from the detection element, and a reset unit configured to initialize the detection element,
wherein the driving unit performs:
a first reset operation of causing the reset units to initialize the detection elements;
a first sampling operation of causing the sampling units to sample a signal from the detection elements in accordance with first radiation irradiation started after the first reset operation;
a first output operation of outputting the signals sampled in the first sampling operation;
a second reset operation of causing the reset units to initialize the detection elements after the first sampling operation;
a second sampling operation of causing the sampling units to sample a signal from the detection elements in accordance with second irradiation started after the second reset operation following the first irradiation; and
a second output operation of outputting the signals sampled in the second sampling operation, and

wherein the driving unit is configured to operate in at least a mode in which the driving unit starts the first output operation after completion of the second reset operation and before the second sampling operation.

2. The apparatus according to claim 1 , wherein the driving unit performs the first output operation in a time shorter than a time from the start of the second irradiation to the end of the second irradiation.

3. The apparatus according to claim 1 , wherein the driving unit performs the first output operation after completion of the second reset operation and before the second sampling operation.

4. The apparatus according to claim 1 , further comprising a radiation source configured to generate radiation and a control unit configured to control the driving unit and the radiation source,
wherein the control unit controls, upon receiving a control signal, to cause the driving unit to make the reset units initialize the detection elements, and controls the radiation source to generate radiation after the driving unit initializes the detection elements.

5. The apparatus according to claim 1 , wherein the driving unit starts the second output operation in a case where irradiation next to the second irradiation is not started over a predetermined period after the second sampling operation.

6. The apparatus according to claim 1 , further comprising a holding unit configured to hold image data based on signals output from the plurality of sensors while the plurality of sensors are not irradiated with radiation.

7. The apparatus according to claim 6 , further comprising a processing unit,
wherein the processing unit forms first image data based on signals output by the first output operation and performs data processing for the first image data by using image data held by the holding unit, and forms second image data based on signals output by the second output operation and performing data processing for the second image data by using image data held by the holding unit.

8. The apparatus according to claim 1 , wherein the driving unit includes, as operation modes, a first mode of starting the first output operation after completion of the second reset operation and a second mode of starting the second reset operation after completion of the first output operation, and
the radiation imaging apparatus further comprises
an information input unit configured to allow a user to input imaging information, and
a mode set unit configured to set the driving unit in one of the first mode and the second mode based on the input imaging information.

9. The apparatus according to claim 8 , wherein the mode setting unit
obtains, based on the input imaging information, a time from the start of the first irradiation to the start of the second irradiation, a time taken for the second irradiation, and a time required for the driving unit to perform the first output operation, and
sets the driving unit in the first mode in a case where the time from the start of the first irradiation to the start of the second irradiation is shorter than a sum of the time taken for the second irradiation and the time required for the driving unit to perform the first output operation.

10. A driving method for a radiation imaging apparatus including a plurality of sensors, each of the plurality of sensors including a detection element configured to detect radiation, a sampling unit configured to sample a signal from the detection element, and a reset unit configured to initialize the detection element, the method comprising:
performing a first reset operation of causing the reset units to initialize the detection elements before the start of first radiation irradiation onto the plurality of sensors;
performing a first sampling operation of causing the sampling units to sample signals from the detection elements in accordance with the first irradiation;
performing a first output operation of outputting the signals sampled in the performing the first sampling operation;
performing a second reset operation of causing the reset units to initialize the detection elements before the start of second irradiation next to the first irradiation;
performing a second sampling operation of causing the sampling units to sample signals from the detection elements in accordance with the second irradiation; and
performing a second output operation of outputting the signals sampled in the performing the second sampling operation,
wherein the performing the first output operation is started after completion of the second reset operation and before the second sampling operation.

11. A non-transitory computer-readable medium storing a computer-executable program for causing a computer to perform the method according to claim 10 .

12. The apparatus according to claim 1 , wherein
the detection element is one of a plurality of detection elements corresponding to the plurality of sensors, respectively,
the sampling unit is one of a plurality of sampling units corresponding to the plurality of sensors, respectively, and
the reset unit is one of a plurality of reset units corresponding to the plurality of sensors, respectively, and wherein
in the first reset operation, the plurality of detection elements are collectively initialized by the plurality of reset units,
in the first sampling operation, signals from the plurality of detection elements in accordance with the first radiation irradiation are collectively sampled by the plurality of sampling units,
in the first output operation, the signals sampled in the first sampling operation are sequentially output from the plurality of sensors,
in the second reset operation, the plurality of detection elements are collectively initialized by the plurality of reset units, after the first sampling operation,
in the second sampling operation, signals from the plurality of detection elements in accordance with the second radiation irradiation are collectively sampled by the plurality of sampling units, and
in the second output operation, the signals sampled in the second sampling operation are sequentially output from the plurality of sensors.

13. A radiation imaging apparatus comprising a plurality of sensors and a driving unit configured to drive the plurality of sensors, the plurality of sensors, respectively, including a plurality of detection elements each configured to detect radiation, a plurality of sampling units

Assignees

• Canon Kk

Inventors

• Dowaki Kanako
• Matsumoto Kazumasa

Classifications

• H04N25/63

  applied to dark current · CPC title

• G01T1/208

  Circuits specially adapted for scintillation detectors, e.g. for the photo-multiplier section · CPC title

• G01T1/2018 Primary

  Scintillation-photodiode combinations · CPC title

• H04N5/32

  Transforming X-rays (cameras or camera modules for generating image signals from X-rays H04N23/30; circuitry of SSIS for transforming X-rays into image signals H04N25/30) · CPC title

• H04N5/361

  Electricity · mapped topic