Patent ID: 8278817

Claim:
A display device comprising: a display region comprising a plurality of picture elements, wherein each of the plurality of picture elements comprises: a first pixel and a second pixel each comprising a first transistor, a second transistor, and a light-emitting element electrically connected to the second transistor, the light-emitting element having a chromaticity whose x-coordinate in a CIE-XY chromaticity diagram is 0.50 or more; a third pixel comprising a first transistor, a second transistor, and a light-emitting element electrically connected to the second transistor, the light-emitting element having a chromaticity whose y-coordinate in the CIE-XY chromaticity diagram is 0.55 or more; and a fourth pixel comprising a first transistor, a second transistor, and a light-emitting element electrically connected to the second transistor, the light-emitting element having a chromaticity whose x-coordinate and y-coordinate in the CIE-XY chromaticity diagram are 0.20 or less and 0.25 or less, respectively; wherein the light-emitting elements provided in the first pixel and the second pixel have different thickness from each other, wherein the first transistors provided in the first pixel and the second pixel are electrically connected to a first signal line, and the second transistors provided in the first pixel and the second pixel are electrically connected to a first power supply line; wherein the first transistor provided in the third pixel is electrically connected to a second signal line, and the second transistor provided in the third pixel is electrically connected to a second power supply line; and wherein the first transistor provided in the fourth pixel is electrically connected to a third signal line, and the second transistor provided in the fourth pixel is electrically connected to a third power supply line.