| 摘要 |
PURPOSE:To reduce noises by inhibiting the gate current of a JFET from flowing when detecting image charge generates at the detection electrode of a charge transfer element by using a source follower amplifier which uses the JFET. CONSTITUTION:An electronic switch 32 composed of an MOSFET which is turned on and off by a rectangular wave voltage phic applied to a terminal 43 and connected to a power source 25 is connected to the point B of a source follower amplifier 2. Then, a charged voltage Vi between t12 and t14, i.e. a correction voltage Vc with a waveform which corresponds to the rectangular wave voltage phic between t11 and t13 a time T earlier than when a voltage VB is developed is applied to the point B. Consequently, a forward current does not flow from the gate of the JFET3 to the source any more. |
