| 摘要 |
PROBLEM TO BE SOLVED: To provide a correlated double sampling circuit that considerably suppresses a fixed pattern noise and to provide an amplifier type solid-state image pickup device employing the circuit. SOLUTION: An input changeover switch 200 is thrown to a position of a vertical signal line 145 for a 1st period and a 1st clamp means (201, 202) clamps a signal on the vertical signal line 145 for a first half of the 1st period and a 1st sample-and-hold means (203, 204) samples and holds the signal at an output side of a clamp capacitor 201 of a last half of the 1st period. Then the input changeover switch 200 is thrown to the position of a fixed level for a 2nd period, the 1st clamp means samples and holds a clamp level with respect to the fixed level for the first half of the 2nd period and the 1st sample-and-hold means samples and holds the signal at the output side of the clamp capacitor 201. Then, a difference between the signals that are sampled and held before and after the 2nd sample-and-hold operation by the 1st sample--and-hold means is obtained.
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