A flat panel detector (FPD) is an X-ray camera (x-ray imaging device) used in digital radiography. In a digital camera, a CCD or CMS sensor receives visible light formed through the lens and converts it into a photograph. On the other hand, the X-ray FPD converts the X-rays that pass through the object to be imaged into electrical signals and creates radiography.

Flat panel detectors are used in X-ray CT, medical x-rays, and mammography in place of conventional X-ray II (image intensifiers) and IP (imaging plates). FPD has a wider dynamic range than X-ray II and does not need to be developed like an IP to view images in real-time.

There are two types of X-ray FPDs: indirect conversion flat panel detectors and direct conversion flat panel detectors.
In the indirect method, the scintillator is laid flat and the emission is detected by a PD (photodiode). It does not use a power supply.
There are two methods of direct type, one using amorphous selenium (a-Se) and the other using cadmium telluride (CdTe). In the amorphous selenium method, a high-voltage bias is applied to the selenium film, and the current flowing turns on the TFT transistor as X-rays enter the film, converting the signal into an image.

Matsusada Precision handles power supplies for applying high voltages to amorphous selenium films.

FPD structure
Related words:
  • Direct Conversion
  • Flat Panel Detector (FPD)
  • amorphous Selenium (a-Se)
  • direct X-ray conversion
  • Imaging Plates (IP)
  • X-ray image intensifier (I.I.)
  • Radiography
  • Computed Tomography (CT)
  • X-ray image sensor

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