| 摘要 |
PURPOSE:To obtain a suitable output signal by switching the storing place of signal charges either a photodetective picture element area or a temporary storage part depending on whether the quantity of incident light reaches a prescribed value or not to control the proportion of a dark current to a signal current. CONSTITUTION:On a P-type semiconductor substrate 11, plural pieces of photodetective picture element areas 12 are formed, and signal charges corre sponding to the quantity of incident light is obtained. In the vicinity of respec tive areas 12, the temporary storage parts 16 are provided through control gates 15. Each part 16 is connected to a common transfer register 18 via respec tive shift gates 17. Also, in the vicinity of the parts 16, an overflow drain area for temporary storage part 25 are respectively provided through intergral clear ing gates 24, so that the unnecessary charges of the parts 16 are discharged into the areas 25 under the control of the gates 24. In such a way, the propor tion of the dark current to signal charges is controlled, and consequently a suitable output signal is obtained.
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