Radiographic imaging device, method of controlling radiation detection sensitivity and program storage medium

• US 9,282,943 B2
• Filed: 07/11/2013
• Issued: 03/15/2016
• Est. Priority Date: 07/13/2012
• Status: Active Grant

• Current Assignee: Fujifilm Corporation (Fujifilm Holdings Corporation)
• Original Assignee: Fujifilm Corporation (Fujifilm Holdings Corporation)
• Inventors: Oda, Yasufumi
• Primary Examiner(s): Midkiff, Anastasia
• Application Number:
  US13/940,027
• Publication Number:
  US 20140016749A1
• Time in Patent Office: 978 Days
• Field of Search: 378/19, 378/91, 378/96, 378/114, 378/162, 378/165, 378/189, 378/204, 378/207, 378/210, 378/901, 250/252.1, 250/370.01, 250/370.08, 250/370.09, 250/370.11, 250/370.14, 250/371, 250/394, 250/395, 348/180, 348/192, 348/193, 348/241, 348/470, 348/533
• US Class Current: 1/1
• CPC Class Codes: A61B 6/4283 characterised by a detector unit being housed in a cassette
• CPC Class Codes: A61B 6/5258 involving detection or reduction of artifacts or noise
• CPC Class Codes: A61B 6/548 Remote control of the apparatus or devices
• CPC Class Codes: A61B 6/585 Calibration of detector units
• CPC Class Codes: G01T 1/247 Detector read-out circuitry for processing gain or off-set correction H04N
• CPC Class Codes: H01L 27/14658 X-ray, gamma-ray or corpuscular radiation imagers measuring X-, gamma- or corpuscular radiation G01T1/00
• CPC Class Codes: H04N 23/30 for generating image signals from X-rays
• CPC Class Codes: H04N 25/60 Noise processing, e.g. detecting, correcting, reducing or removing noise
• CPC Class Codes: H04N 25/623 by evacuation via the output or reset lines
• CPC Class Codes: H04N 25/67 applied to fixed-pattern noise, e.g. non-uniformity of response
• CPC Class Codes: H05G 1/56 Switching-on; Switching-off

Abstract

A radiographic imaging device including: a sensor portion that generates an output signal according to an irradiated amount of irradiated radiation; a detector that based on the output signal detects a radiation irradiation start of radiation irradiated from a radiation source during capture of a radiographic image; a noise data generation means that, based on an output signal from the sensor portion in a non-irradiation state of radiation from the radiation source, generates noise data relating to noise incorporated in the output signal; a controller that controls detection sensitivity to radiation irradiation start in the detector according to a degree of variation in noise level expressed by the noise data; and an imaging unit that captures the radiographic image after radiation irradiation start has been detected by the detector.

Claims

1. A method of performing radiographic imaging comprising:

generating an output signal according to an irradiated amount of irradiated radiation using a sensor portion;

using a detector to detect, based on the output signal, a radiation irradiation start of radiation irradiated from a radiation source during capture of a radiographic image;

generating noise data with a noise data generator that, based on an output signal from the sensor portion in a non-irradiation state of radiation from the radiation source, generates noise data relating to noise incorporated in the output signal;

using a controller to controls detection sensitivity to radiation irradiation start in the detector according to a degree of variation in noise level expressed by the noise data; and

,

capturing the radiographic image with an imaging unit after radiation irradiation start has been detected by the detector, wherein;

the controller lowers detection sensitivity to radiation irradiation start in the detector the greater the variation in the noise level expressed by the noise data;

the detector includes an amplifier circuit that amplifies the output signal; and

,

the controller lowers detection sensitivity to radiation irradiation start by the detector by reducing the gain of the amplification circuit the greater the variation in the noise level expressed by the noise data.

2. The radiographic imaging method of claim 1, wherein

the noise data generator sequentially updates the noise data based on the output signal sequentially supplied from the sensor portion;

and

the controller derives the gain based on the most up-to-date noise data.

3. A method of performing radiographic imaging comprising:

generating an output signal according to an irradiated amount of irradiated radiation using a sensor portion;

a detector to detect based on the output signal, a radiation irradiation start of radiation irradiated from a radiation source during capture of a radiographic image;

generating noise data with a noise data generator that, based on an output signal from the sensor portion in a non-irradiation state of radiation from the radiation source, generates noise data relating to noise incorporated in the output signal;

using a controller to control detection sensitivity to radiation irradiation start in the detector according to a degree of variation in noise level expressed by the noise data; and

,

capturing the radiographic image with an imaging unit after radiation irradiation start has been detected by the detector, wherein;

the detector includes a charge amplifier that includes a capacitor that accumulates charge output as the output signal from the sensor portion, and that generates an electric signal according to a charge amount accumulated in the capacitor; and

,

the controller makes a charge accumulation duration of the capacitor longer the greater the noise level variation expressed by the noise data.

4. The radiographic imaging method of claim 3, wherein

the noise data generator sequentially updates the noise data based on the output signal sequentially supplied from the sensor portion;

and

the controller derives the charge accumulation duration based on the most up-to-date noise data.

5. A method of performing radiographic imaging comprising:

generating an output signal according to an irradiated amount of irradiated radiation using a sensor portion;

using a detector to detect, based on the output signal, a radiation irradiation start of radiation irradiated from a radiation source during capture of a radiographic image;

generating noise data with a noise data generator that, based on an output signal from the sensor portion in a non-irradiation state of radiation from the radiation source, generates noise data relating to noise incorporated in the output signal;

using a controller to control detection sensitivity to radiation irradiation start in the detector according to a degree of variation in noise level expressed by the noise data; and

,

capturing the radiographic image with an imaging unit after radiation irradiation start has been detected by the detector, wherein;

the noise data generator generates a histogram based on the plurality of sampling values.