| 摘要 |
PURPOSE:To measure the quality of a charge coupled device (CCD) with higher speed and with higher accuracy, by a method wherein with a switch changed over, the absolute value output and the relative value output of a charge coupled device (CCD) are sample-held to process digitally. CONSTITUTION:The output of a CCD is supplied via a coaxial cable C to a buffer amplifier 3 that has been impedance-matched. And when a mode change-over switch 7 is connected to a contact point (a), the absolute value output is held in a sample hold circuit 10 to which a prescribed clock signal to control the CCD is applied. The absolute output is stored via an A/D converter 11 in an RAM12. On the other hand, when the switch 7 is connected to a contact point b, the relative output of the difference between said absolute output and the absolute output held in the sample hold circuit 5 from a differential amplifier 6 is held in the circuit 10, and the digital value is written in the RAM12. When the stored contents in the RAM12 are processed digitally, the quality of the CCD such as average voltage, lacks of bits and existence of noises in the CCD output is measured with higher speed and higher accuracy. |
