C11440-42U/C11440-42U01 Instruction manual_Ver.1.1
9. DESCRIPTION OF VARIOUS FUNCTIONS
9-1 THEORY OF CMOS IMAGE SENSOR
The pixel of a CMOS image sensor is composed of the photodiode and the amplifier that
converts the charge into voltage. Entered light is converted to charge and converted to voltage in
the pixel. The voltage of each pixel is output by switching the switch one by one. (Figure 9-1)
The FL-400 scientific CMOS image sensor used in this camera has an on-chip CDS (correlated
double sampling) circuit, which plays an important role in achieving low noise. In addition, the
FL-400 realizes both low noise and high speed readout simultaneously, by a split readout
scheme in which the top and the bottom halves of the sensor are readout independently, and the
data of each horizontal line is read by 2 lines of column amplifier and A/D in the top and the
bottom in parallel and simultaneously.
Figure 9-1 Structure of the FL-400
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