The invention relates to an active matrix of thin-film transistors or TFTs
for an optical sensor, comprising a matrix of transistors formed on a
substrate comprising a gate, a drain and a source, a set of rows and a
set of columns that are connected to the gates and to an electrode of the
transistor, respectively, pixel electrodes and, according to the
invention, a set of capacitive electrodes lying at the same level as the
electrodes of the transistors so as to form, with the pixel electrodes,
storage capacitors.