Method for processing information delivered by a sensor pixel matrix offering a wide dynamic range and gain and corresponding sensor

1. An image sensor, comprising:

a matrix of active pixels, wherein each pixel comprises a photodiode and a follower transistor whose gate is connected to the photodiode;

one pair of sampling capacitors per matrix column for processing the information delivered by the matrix of active pixels;

a differential amplifier per matrix column configured in follower mode and connected between the pixels of the column and the pair of sampling capacitors via a pair of switches; and

an additional amplifier with unity gain connected between the output of the differential amplifier and the pair of switches associated with the sampling capacitors, the additional amplifier sourcing current for sufficiently and quickly charging the capacitors;

wherein the differential amplifier configured in follower mode comprises:

a differential pair comprising the follower transistor of the pixel and an additional transistor, the source of the follower transistor being connected to a source of biasing current via a row-selection transistor, the source of the additional transistor being also connected to the said biasing current source, the drain of the additional transistor being fed back onto the gate of the additional transistor, and

a current mirror connected between the drain of the follower transistor and the drain of the additional transistor,

wherein the gate of the follower transistor of the pixel forms the positive input of the differential amplifier and the gate of the additional transistor forms the negative input of the differential amplifier.

2. The image sensor according to claim 1 , wherein each pixel also comprises a reset transistor, the sensor further comprising, per matrix column, a pixel supply line to which are connected the reset transistors for the column pixels, and in that this supply line is distinct from a bit line to which is connected the differential amplifier.

3. The image sensor according to claim 1 , wherein each pixel also comprises a reset transistor, and wherein the drain of the follower transistor and the reset transistor of each column pixel are connected to a bit line to which is connected the current mirror of the differential amplifier, and wherein this bit line is supplied via a controlled switch, and wherein the sensor comprises control means operable to simultaneously turn on the reset transistor and close the switch, then simultaneously turn off the reset transistor and open the switch.

4. The image sensor according to claim 1 , wherein the follower transistor of each pixel is a double-oxide or single-oxide transistor.

5. The image sensor according to claim 1 , wherein the sensor is included within a video camera device.