| 摘要 |
PURPOSE:To realize a high-sensitivity image pickup element with less random noise by a method wherein a level shift circuit adds to an inversion amplifier inserted between a transfer transistor and a vertical signal line capacitating a depletion mode transistor with low 1/f noise to work as a driving transistor. CONSTITUTION:A level shift circuit A composed of transistors 44, 45 is located between a transfer transistor 41 and the output terminal of an inversion amplifoer constituted of transistors 42, 43. This causes the threshold voltage of the transistor 41 to be apparently higher by the level shift voltage VGS. The increase sufficiently makes up for the threshold voltage that may be low of the driving transistor 43. The leve shift voltage may be freely regulated with the transistor 45 controlling the current in the transistor 44. Of the noise present in the level shift circuit A itself, especially when a depletion mode transistor is used, the level of the 1/f component changes subject to the current level. Operation is possible in the region of low 1/f noise when the quantity of level shift is regulated for the proper operation of the inversion amplifier.
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