Patent ID: 7804467

Claim:
A display device comprising a pixel region comprising: a source signal line; a power supply line; and a pixel comprising: a first transistor electrically connected between the source signal line and a pixel electrode; a second transistor electrically connected between the power supply line and the pixel electrode; a third transistor electrically connected between a gate electrode of the second transistor and a drain electrode of the first transistor, a first resistor electrically connected between the first transistor and the pixel electrode; a second resistor electrically connected between the second transistor and the pixel electrode; a substrate; a sealing member including a recess portion over the substrate, and a hygroscopic material or a material which is capable of absorbing oxygen provided in the recess portion, wherein the source signal line, the power supply line and the pixel are formed over the substrate, wherein a gate electrode of the first transistor is electrically connected to the gate electrode of the second transistor, wherein the first transistor, the second transistor and the third transistor are n-channel transistors, wherein each of the gate electrode of the first transistor and the gate electrode of the second transistor comprises a first conductive layer and a second conductive layer formed over the first conductive layer, wherein an edge portion of the first conductive layer is made into a first tapered shape, wherein an edge portion of the second conductive layer is made into a second tapered shape, wherein an angle of the first tapered shape is smaller than an angle of the second tapered shape, wherein the first conductive layer and the second conductive layer are formed over a semiconductor layer, and wherein an insulating film is formed over and in contact with the first conductive layer and the second conductive layer.