| 摘要 |
PURPOSE:To form a solid-state image pickup device having AGC functions with a wider dynamic range by designing so that the gains of outputs corresponding to the storage amount of a signal electric charge generated at a photodetection section take > 2 kinds of values. CONSTITUTION:The potential change FG of a floating gate 9 has a high gain at a period 20 when the electric charge is stored in the gate 9 only and the FG has a comparatively lower gain during a period 21 when the charge is stored in both a storage electrode 19 and the gate 9 by selecting properly the shape of the floating gate 9 and the storage electrode 19. A threshold level generating a signal for completing the storage period through the characteristic above is set to a threshold value Vth1 during high gain period when the incident luminous amount is weak and the signal electric charge is small and the level is set to a threshold value Vth2 during a low gain period when the incident luminous amount is intense. In setting the threshold level in this way, the AGC function is exerted on the incident luminous amount with a wider range.
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