Patent ID: 8599191

Claim:
A data extraction system for an organic light emitting device (OLED) based display, the system comprising: a pixel circuit including a drive transistor, an organic light emitting device, and a programming input coupled to the gate of the drive transistor, the drive transistor having a source or a drain coupled to the OLED; a charge-pump amplifier having an input and an integrated voltage output; a switch module including an input coupled to the output of the pixel circuit and an output coupled to the input of the charge-pump amplifier, the switch module including switches to steer current in and out of the pixel circuit, provide a discharge path between the pixel circuit and the charge-pump amplifier and isolate the charge-pump amplifier from the pixel circuit; and a controller coupled to the pixel circuit, charge-pump amplifier and the switch module, the controller controlling voltage inputs to the pixel circuit, charge-pump amplifier and switch module in a predetermined sequence to produce an output voltage value which is a function of a parameter of the pixel circuit, the sequence including providing a program voltage to the programming input to either pre-charge a capacitance of the pixel circuit to a charge level and transfer the charge to the charge-pump amplifier via the switch module to generate the output voltage value, or provide a current from the pixel circuit to the charge-pump amplifier via the switch module to produce the output voltage value by integration; a select transistor coupled between the programming input and the gate of the drive transistor; and an output transistor having a source or drain coupled to the source or drain of the drive transistor, a source or drain coupled to said charge-pump amplifier, and a gate coupled to a read signal line.