| 摘要 |
PROBLEM TO BE SOLVED: To provide with a simple circuit constitution a clamping circuit for a solid-state image pickup device which obtains high image quality by significantly suppressing the noises caused by the clamping operations. SOLUTION: Pixel signals are inputted to a clamp capacity Cc, and the DC components of the pixel signals are cut off by the capacity Cc and only the varying components (AC components) of these signals are inputted to an inverting amplifier A through the capacity Cc. When the 1st and 2nd switches SW1 and SW2 are closed in response to a control signal ϕc, the input and output of the amplifier A are short-circuited, and a clamp potential V1 is given to the input and output of the amplifier A. When the switches SW1 and SW2 are opened and the input and output of the amplifier A are opened, the varying components vi of the pixel signals inputted via the capacity Cc are amplified by -α times by the amplifier A. Then the varying components vo are outputted from the amplifier A. |
