Light-emitting device

Abstract

A light-emitting device in which variation in luminance of pixels is suppressed. A light-emitting device includes at least a transistor, a first wiring, a second wiring, a first switch, a second switch, a third switch, a fourth switch, a capacitor, and a light-emitting element. The first wiring and a first electrode of the capacitor are electrically connected to each other through the first switch. A second electrode of the capacitor is connected to a first terminal of the transistor. The second wiring and a gate of the transistor are electrically connected to each other through the second switch. The first electrode of the capacitor and the gate of the transistor are electrically connected to each other through the third switch. The first terminal of the transistor and an anode of the light-emitting element are electrically connected to each other through the fourth switch.

1 . (canceled) 
     
     
         2 . A light-emitting device comprising:
 a semiconductor film;   a first conductive film overlapping with a first region of the semiconductor film;   a second conductive film overlapping with a second region of the semiconductor film;   a third conductive film over and in contact with a third region of the semiconductor film;   a fourth conductive film overlapping with a fourth region of the semiconductor film; and   a pixel electrode of a light-emitting element over and electrically connected to the third conductive film,   wherein the first region of the semiconductor film is configured to be a channel formation region of a first transistor, and the first conductive film is configured to be a gate of the first transistor,   wherein the second region of the semiconductor film is configured to be a channel formation region of a second transistor, and the second conductive film is configured to be a gate of the second transistor,   wherein the fourth region of the semiconductor film is configured to be a first electrode of a capacitor, and the fourth conductive film is configured to be a second electrode of the capacitor,   wherein the semiconductor film further comprises an impurity region adjacent to the first region and the second region,   wherein the impurity region is configured to be one of a source and a drain of the first transistor and one of a source and a drain of the second transistor,   wherein in a top view, the channel formation region of the first transistor has a bent part, and   wherein the first transistor is configured to control current supplied to the light-emitting element.   
     
     
         3 . The light-emitting device according to  claim 2 , wherein the third region of the semiconductor film is configured to be the other of the source and the drain of the second transistor. 
     
     
         4 . The light-emitting device according to  claim 2 , wherein the semiconductor film comprises silicon. 
     
     
         5 . The light-emitting device according to  claim 2 , wherein the semiconductor film comprises polycrystalline silicon. 
     
     
         6 . The light-emitting device according to  claim 2 , wherein the first transistor and the second transistor have a same polarity. 
     
     
         7 . A light-emitting device comprising:
 a semiconductor film;   a first conductive film overlapping with a first region of the semiconductor film;   a second conductive film overlapping with a second region of the semiconductor film;   a third conductive film over and in contact with a third region of the semiconductor film;   a fourth conductive film overlapping with a fourth region of the semiconductor film; and   a pixel electrode of a light-emitting element over and electrically connected to the third conductive film,   wherein the first region of the semiconductor film is configured to be a channel formation region of a first transistor, and the first conductive film is configured to be a gate of the first transistor,   wherein the second region of the semiconductor film is configured to be a channel formation region of a second transistor, and the second conductive film is configured to be a gate of the second transistor,   wherein the fourth region of the semiconductor film is configured to be a first electrode of a capacitor, and the fourth conductive film is configured to be a second electrode of the capacitor,   wherein the semiconductor film further comprises an impurity region adjacent to the first region and the second region,   wherein the impurity region is configured to be one of a source and a drain of the first transistor and one of a source and a drain of the second transistor,   wherein the other of the source and the drain of the first transistor is electrically connected to a first wiring,   wherein in a top view, the channel formation region of the first transistor has a bent part, and   wherein the first transistor is configured to control current supplied to the light-emitting element.   
     
     
         8 . The light-emitting device according to  claim 7 , wherein the third region of the semiconductor film is configured to be the other of the source and the drain of the second transistor. 
     
     
         9 . The light-emitting device according to  claim 7 , wherein the semiconductor film comprises silicon. 
     
     
         10 . The light-emitting device according to  claim 7 , wherein the semiconductor film comprises polycrystalline silicon. 
     
     
         11 . The light-emitting device according to  claim 7 , wherein the first transistor and the second transistor have a same polarity.