Radiation detector, radiographic imaging device and radiographic imaging system

• US 9,366,766 B2
• Filed: 06/21/2012
• Issued: 06/14/2016
• Est. Priority Date: 07/07/2011
• Status: Active Grant

• Current Assignee: Fujifilm Corporation (Fujifilm Holdings Corporation)
• Original Assignee: Fujifilm Corporation (Fujifilm Holdings Corporation)
• Inventors: Okada, Yoshihiro
• Primary Examiner(s): Porta, David
• Assistant Examiner(s): Malevic, Djura
• Application Number:
  US13/528,857
• Publication Number:
  US 20130009065A1
• Time in Patent Office: 1,454 Days
• Field of Search: 250/394, 250/390.09, 250/370.08, 250/366, 250/363.02
• US Class Current: 1/1
• CPC Class Codes: G01T 1/20184 Detector read-out circuitry, e.g. for clearing of traps, compensating for traps or compensating for direct hits
• CPC Class Codes: H04N 23/30 for generating image signals from X-rays
• CPC Class Codes: H04N 5/32 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

Abstract

The present invention provides a radiation detector, a radiographic imaging device and a radiographic imaging system that may detect radiation with high precision. Namely, in the radiation detector, radiation detection pixels include detection TFTs, and light that has been converted from radiation is illuminated directly from a scintillator onto the detection TFTs. Accordingly, leak current occurs in semiconductor active layers of the detection TFTs corresponding to the amount (intensity) of the illuminated light, and the leak current flows in to signal lines. Accordingly, radiation may be detected by monitoring the leak current, and enables timings, such as the start of irradiation of radiation, to be detected.

Claims

1. A radiation detector comprising:

a conversion section that converts radiation into light and illuminates the light;

a plurality of pixels, disposed in a matrix, each pixel including a pixel region, and within the pixel region, each of the plurality of pixels including;

a sensor portion that generates charges due to illumination of light, and that includes a photoelectric conversion section provided below the conversion section such that the photoelectric conversion section overlaps with a section of the conversion section; and

a switching element, provided below the photoelectric conversion section, that output charges generated in the sensor portion to a signal line,

wherein each of a predetermined plurality of radiation detection pixels that are employed for radiation detection from among the plurality of pixels includes a detection TFT, provided within the pixel region and below a region of the conversion section not overlapping with the photoelectric conversion section, that outputs electric signals according to the illuminated light to the signal line.

2. The radiation detector of claim 1, wherein the detection TFT is directly illuminated with light from the conversion section.

3. The radiation detector of claim 1 wherein the detection TFT is applied with a bias voltage.

4. The radiation detector of claim 1 wherein the detection TFT comprises a gate electrode to which a voltage is applied for controlling an amount of current of the electric signals output.

5. The radiation detector of claim 1 wherein, out of the plurality of pixels, the detection TFT provided to each pixel, other than the radiation detection pixels, is not connected to the signal line.

6. The radiation detector of claim 1 wherein the correspondence relationship between irradiated radiation amount and charge amount generated by the sensor portion, matches the correspondence relationship between the irradiated radiation amount and charge amount of the electric signals output from the detection TFT.

7. The radiation detector of claim 1 wherein the sensor portion comprises a light blocking section that blocks light from being illuminated onto the photoelectric conversion section other than the light illuminated from the conversion section.

8. A radiographic imaging device comprising:

the radiation detector of claim 1;

a detection section that detects radiation amount based on charges output from the detection TFT of the radiation detector; and

an imaging section that acquires a radiographic image based on charge amount output from the sensor portions.

9. The radiographic imaging device of claim 8 further comprising:

a read circuit, provided to each of the signal lines of the radiation detector, that read out the charges output to the signal lines,

wherein the detection TFT of the radiation detector outputs the electric signals to the signal line.

10. A radiographic imaging system comprising:

a radiation irradiation section; and

the radiographic imaging device of claim 8 that images a radiographic image of radiation irradiated from the radiation irradiation section.