Patent ID: 8779666

Claim:
A compensation circuit for keeping luminance intensity of a diode, comprising: a first transistor, coupled to a first power supply, a first control signal and a first node; a second transistor, coupled to a second power supply, the first control signal and a second node; a stabilization unit comprising a photodiode and a capacitor both connected in series between the first node and second node; a third transistor, coupled to a third power supply, a second control signal and a common node between the photodiode and the capacitor; a light emitting diode, having a first terminal coupled to the third power supply and coupled to the common node between the photodiode and the capacitor through the third transistor; and a fourth transistor, coupled to the first node, the first power supply and a second terminal of the light emitting diode, wherein the fourth transistor is turned on to conduct the light emitting diode.