Radiographic imaging device, method of controlling radiation detection sensitivity and program storage medium
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.
1. A radiographic imaging device comprising:
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 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;
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, 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 device 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 radiographic imaging device comprising
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 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;
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, 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 device 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 radiographic imaging device comprising:
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 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;
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, wherein:
the noise data generator generates the noise data based on a plurality of sampling values obtained by sampling the level of electric signals according to the output signal from the sensor portion in the non-irradiation state of radiation; and
the noise data generator generates a histogram based on the plurality of sampling values.