Patent ID: 7554514

Claim:
A pixel circuit comprising: a light-emitting element for emitting light according to a driving current supplied through a predetermined path; a photoelectric transducer for receiving the light emitted from the light-emitting element to output a photoelectric current according to the received light; a first capacitor for storing as an electric charge the integral value of the photoelectric current output from the photoelectric transducer; a comparator for changing a level of an output voltage at a timing when a first voltage set according to the electric charge stored in the first capacitor reaches a second voltage set according to data supplied through a data line; a first switching element electrically controlled according to the output voltage output from the comparator for making the light-emitting element emit the light when the first voltage has not reached the second voltage and for making the light-emitting element stop emitting the light when the first voltage reaches the second voltage; a second capacitor for storing the data supplied through the data line; and a driving transistor having its gate connected to the second capacitor for generating the driving current according to the data stored in the second capacitor; wherein the first switching element is provided in parallel with the second capacitor, to electrically separate a pair of electrodes of the second capacitor from each other when the first voltage has not reached the second voltage and to electrically connect the pair of electrodes of the second capacitor to each other when the first voltage reaches the second voltage.