| 摘要 |
PURPOSE:To obtain a digital signal corresponding to an optical input by forming a floating diffusion layer region having a conduction type reverse to a substrate and shaping an input gate, which can be controlled by the potential of the region, and an input-section diffusion layer region having the conduction type reverse to the substrate. CONSTITUTION:Beams projected to a photoelectric conversion section 1 are converted in a photoelectric manner, and generated charges are stored for a fixed period, overflow through a gate 4 set at predetermined potential, and are stored in a floating diffusion layer region 5. The potential of the region 5 changes by the charges, and the potential of an input gate 8 and an input-section diffusion layer region 9 is controlled. The exchange of charges between the photoelectric conversion section 1 and the region 9 by the control is completed, a transfer gate 2 is opened, and charges in the photoelectric conversion section 1 are discharged to a transfer section 3. When charges by an optical input exceed some threshold, charges are not fed into the transfer section 3, that is, charges in the transfer section 3 are zero; when charges by the optical input extend over some threshold or less, some constant charges flow into the transfer section 3, that is, charges in the transfer section 3 reach to 1. Accordingly, digital signals corresponding to optical inputs are obtained. |
