Patent ID: 8154484

Claim:
An organic light emitting display, comprising: a first power generator for generating a first power; a second power generator for generating a second power; a plurality of pixels, each pixel comprising an organic light emitting diode, wherein at least some pixels among the plurality of pixels are in a display region of the organic light emitting display, and the at least some pixels each comprise a driving transistor for controlling a first current through the organic light emitting diode; and a voltage controller for supplying a second current to the organic light emitting diode of at least one specific pixel of the plurality of pixels, and for controlling a voltage of the second power in accordance with a first voltage of the organic light emitting diode provided when the second current is supplied to the organic light emitting diode, wherein each specific pixel comprises a first transistor coupled between the organic light emitting diode of the specific pixel and the voltage controller, and wherein the voltage controller comprises: a controller for controlling a turn-on and a turn-off of the first transistor, the controller comprising: a memory for storing first data representing a saturation voltage for driving the driving transistor in a saturation region, and a margin voltage corresponding to a range of process deviation of the driving transistor when the driving transistor supplies a maximum current; and a register for generating second data, wherein the register is configured to adjust a value of the second data in accordance with a comparator output; a first digital-analog converter for converting the first data into a second voltage; a current source for supplying the second current to the organic light emitting diode when the first transistor is turned on; an adder for adding the first voltage and the second voltage to generate a third voltage; a comparator for comparing the third voltage with a voltage of the first power, and for supplying the comparator output; and a second digital-analog converter for converting the second data to an analog voltage.