| 摘要 |
PROBLEM TO BE SOLVED: To quickly and correctly perform irradiation and detection of a radiation.SOLUTION: An electronic cassette detects start of irradiation of an X-ray from an X-ray source using the pixel of an FPD by itself. The FPD can read a signal charge from the pixel in a nondestructive manner, and can change the gain of the signal output from the pixel. The electronic cassette initially reads an output signal by setting the gain of the pixel at a high gain GnH to perform primary determination of determining whether or not a signal value SV is equal to or greater than a threshold Th in the operation of irradiation start detection. The electronic cassette reads an output signal by changing the gain of the pixel to a low gain GnL to perform secondary determination with the signal value SV when the primary determination is confirmed. The electronic cassette can detect irradiation start at a stage where the intensity of the X-ray is low since it performs the primary determination with the high gain GnH, and can perform correct detection since it performs the secondary determination with the low gain GnL.SELECTED DRAWING: Figure 5 |
