Patent ID: 8212581

Claim:
A method of detecting defective electroluminescent (EL) emitters in an EL display, comprising: a) providing the electroluminescent (EL) display having a plurality of subpixels, each having an EL emitter with a first and a second electrode, a drive transistor with a first electrode, a second electrode connected to the first electrode of the EL emitter, and a gate electrode, and a readout transistor with a first electrode connected to the second electrode of the drive transistor, a second electrode and a gate electrode; b) providing a first voltage source associated with the first electrode of the drive transistor in each of the plurality of subpixels; c) providing a second voltage source connected to the second electrode of the EL emitter in each of the plurality of subpixels; d) providing a current source associated with the second electrode of the readout transistor; e) selecting an EL subpixel and its corresponding drive transistor, readout transistor and EL emitter; f) providing a voltage measurement circuit associated with the second electrode of the selected readout transistor; g) turning off current/low through the selected drive transistor; h) providing a selected test current through the EL emitter using the current source; i) measuring the voltage at the second electrode of the selected readout transistor using the voltage measurement circuit to provide a corresponding status signal representative of characteristics of the selected EL emitter; j) repeating steps e through i for each remaining EL subpixel in the plurality of EL subpixels; k) selecting an EL subpixel; l) selecting a subpixel neighborhood for the selected EL subpixel, wherein the subpixel neighborhood includes at least two subpixels adjacent to the selected EL subpixel; m) comparing the status signal for the selected EL subpixel to the respective status signals of each of the subpixels in the selected subpixel neighborhood to determine whether the selected EL emitter is defective; and n) repeating steps k through m for each remaining EL subpixel in the plurality of EL subpixels to detect other defective EL emitters in the EL display.