Fpd is known as flat panel detector in Chinese.
The flat panel detector is a sophisticated and valuable device that plays a decisive role in the quality of imaging, and familiarizing yourself with the detector's performance indicators can help to improve the quality of imaging and reduce the dose of X-ray radiation.
Digital radiography (DR), with its faster imaging speed, more convenient operation, higher imaging resolution and other significant advantages, has become the dominant direction of digital radiography technology. DR flat panel detector from the energy conversion can be divided into two types: indirect conversion flat panel detector and direct conversion flat panel detector.
The principle of flat panel detector:
The flat panel detector has amorphous silicon flat panel detector and amorphous selenium flat panel detector.
Amorphous selenium flat-panel detector is a direct flat-panel detector structure, which is mainly composed of a collector matrix, selenium layer, dielectric layer, top electrode and protective layer.
Amorphous selenium array directly converts X-rays into electrical signals, which are memorized in the storage capacitor. The pulse control gate circuit makes the thin-film transistor conductive, and sends the charge memorized in the storage capacitor to the output of charge amplifier, which completes the conversion of photoelectric signals, and then converts them into digital images by the digital converter and inputs them into the computer.
Amorphous silicon flat-panel detector for indirect digital X-ray imaging, its basic structure for the surface is a layer of scintillator material, and then the next layer of amorphous silicon as the material of the photodiode circuit, the bottom layer of the charge readout circuit .
Scintillator located on the surface of the detector through the body after the attenuation of X-rays converted to visible light, scintillator under the amorphous silicon photodiode array will be converted to electrical signals, in the photodiode capacitance of the diode itself to form a storage charge, and then scanning and read out the individual pixel of the storage charge, after the output of digital signals by the A/D converter, transmitted to the computer for image processing to form the X-ray digital image.