A photodetector according to an embodiment includes; at least one photodiode including: a first electrode; an n-type semiconductor layer disposed on the first electrode; a first p-type semiconductor layer disposed above the n-type semiconductor layer, the first p-type semiconductor layer including a first surface region and a second surface region; a second p-type semiconductor layer disposed in the first surface region of the first p-type semiconductor layer, the second p-type semiconductor layer having a higher p-type impurity concentration than the first p-type semiconductor layer; and a second electrode disposed on the second surface region of the first p-type semiconductor layer and on the second p-type semiconductor layer.

The image quality and useful life of an x-ray imaging detector is enhanced by adding a shield layer between the photodiode/thin film transistor (TFT) array and the cesium iodide (CsI)-based scintillator/scintillator layer. The shield layer prevents dynamic charge coupling between a CsI/parylene layer located above the shield layer and the conductive data transfer lines located below the shield layer and operably connected to the individual pixels of the photodiode/TFT array to effectively maintain the level of various image quality parameters over time, including the modulation transfer function (MTF), and the Signal to Noise Ratio (SNR).

To improve a temporal resolution.

An image-capturing device includes a pixel array unit and a control unit. The pixel array unit includes a plurality of pixels classified into two or more groups, wherein pixels which belong to a same group are driven at a same timing. The control unit controls driving of the pixel array unit so that a number of groups in a period of time of read-out of electrical charge is a same number in any given timing in image-capturing operation, and that a number of groups in a period of time of exposure and accumulation of electrical charge is a same number in any given timing in the image-capturing operation.

A pixel includes a conversion element detecting radiation, and a switch between the element and a signal line. A readout unit reads out a signal on the signal line. The readout unit includes a reset unit that resets a potential of the signal line. A period during which the readout unit reads out a signal on the signal line includes a first period during which the signal line is reset, and a signal on the signal line in a state that the switch is not turned on is read out, and a second period during which the signal line is reset, and a signal on the signal line due to the switch being turned on is read out. The processing unit calculates a difference between the signals read out in the second and first periods.

An X-ray image pickup system (10) includes an X-ray source (16), an image pickup panel (12), a scintillator (13), and an X-ray control unit (14E). The image pickup panel includes a photoelectric conversion element (26), a capacitor (50), a thin film transistor (24), and TFT control units (14A, 14B, 14F). To the photoelectric conversion element (26), scintillation light is projected. The capacitor (50) is connected to the photoelectric conversion element (26), and accumulates charges. The thin film transistor (24) is connected to the capacitor (50). The TFT control units (14A, 14B, 14F) control an operation of the thin film transistor (24). The thin film transistor (24) includes a semiconductor active layer (32) made of an oxide semiconductor. The X-ray control unit (14E) intermittently projects X-ray to the X-ray source (16). The TFT control units (14A, 14B, 14F) cause the thin film transistor (24) to operate when the X-ray is not projected, so as to read out the charges accumulated in the capacitor (50).

Improvement of the dynamic range of a radiation detector is described. In one embodiment, one or more non-destructive readout operations are performed during a radiation exposure event to acquire data used to improve the dynamic range of the detector. In one implementation, one or more non-destructive readouts of pixels are performed prior to saturation of the pixels during an X-ray exposure so as to obtain non-saturated measurements at the pixels. In an additional implementation, non-destructive readouts of pixels are performed between exposure events so as to obtain an estimate of electronic noise during a multi-exposure examination.

A radiation imaging apparatus is provided. The apparatus comprises first pixels arranged in an image sensing region to obtain a radiation image, a second pixel configured to obtain a dose of incident radiation and a control unit configured to control the first pixels and the second pixel. The control unit causes the first pixels to accumulate charge corresponding to a radiation dose, while causing the second pixel to operate in a detection cycle determined based on irradiation information of radiation before irradiation with radiation, obtains a dose of incident radiation for each detection cycle, and corrects the obtained radiation dose in accordance with an amount of noise output from the second pixel operating in the detection cycle.

A radiation imaging apparatus is provided. The apparatus comprises first pixels arranged in an image sensing region to obtain a radiation image, a second pixel configured to obtain a dose of incident radiation and a control unit configured to control the first pixels and the second pixel. The control unit causes the first pixels to accumulate charge corresponding to a radiation dose, while causing the second pixel to operate in a detection cycle determined based on irradiation information of radiation before irradiation with radiation, obtains a dose of incident radiation for each detection cycle, and corrects the obtained radiation dose in accordance with an amount of noise output from the second pixel operating in the detection cycle.

A radiation image sensing apparatus includes an image sensor configured to sense a plurality of radiation images at a frame rate according to a synchronization signal, and a controller configured to control the image sensor. In a case in which the frame rate is lower than a predetermined frame rate, the controller causes the image sensor to perform a temperature controlling operation of generating additional heat other than heat generated by an image sensing operation in addition to the image sensing operation so as to reduce a change in a temperature of the image sensor.

An electronic cassette has a detection panel (light detection substrate) in which pixels for accumulating electric charges corresponding to radiation are arranged. The electronic cassette includes two gate control circuits that control an operation of a gate drive circuit, a power supply circuit that supplies power to the gate control circuits, a first wiring line, and a second wiring line. The first wiring line connects the power supply circuit and each of two gate control circuits to each other, and supplies each of two gate control circuits with the power supplied from the power supply circuit. The second wiring line connects two gate control circuits to each other. The power supplied from the power supply circuit to one of two gate control circuits is diverted to the other, through the second wiring line.