| 摘要 |
An electron multiplication gain calibration device, for stabilizing gain of an electron multiplying charge coupled device (CCD) imaging device 4, comprises a gain adjusting section 5 and control section 8. Gain adjusting section 5 is provided independently of gain adjustment 11 for the electron multiplying part of CCD 4, and sets a reference gain. Control section 8 calibrates the CCD gate voltage for a desired electron multiplication gain by comparing a video level amplified by the electron multiplication gain to a video level amplified by the reference gain. The control section sets an initial value of the gate voltage, which is supposed to provide the electron multiplication gain equal to the reference gain, and controls the gate voltage so that the video level amplified by the electron multiplication gain becomes equal to that amplified by the reference gain (i.e. without electron multiplication). Thus, the system compensates for drift or shift in the electron multiplication gain characteristic with time. |
