Semiconductor device and driving method thereof

Abstract

To reduce adverse effect of variations in threshold voltage. A semiconductor device includes a transistor including a gate connected to one electrode of a capacitor and one terminal of a SW1, a source and a drain one of which is connected to one terminal of a SW2 and one terminal of a SW3 and the other of which is connected to the other terminal of the SW1 and one terminal of a SW4; a first wiring electrically connected to the other terminal of the SW2; a second wiring electrically connected to the other terminal of the SW4; a load including electrodes one of which is connected to one electrode of the capacitor and the other terminal of the SW3; and a third wiring connected to the other electrode of the load.

What is claimed is: 
     
       1. A display module comprising:
 a display panel comprising: a semiconductor device pixel comprising:
 a first transistor; 
 a second transistor; 
 a third transistor; 
 a fourth transistor; 
 a fifth transistor; 
 a capacitor; and 
 a load light-emitting element; and 
 a first line; 
 a second line; and 
 a third line; and 
   at least one of flexible printed circuit and printed circuit,   
 wherein:
 one of a source and a drain of the first transistor is electrically connected to the first a power supply line; 
 one of a source and a drain of the second transistor is electrically connected to the other of the source and the drain of the first transistor; 
 the other of the source and the drain of the second transistor is electrically connected to one of a source and a drain of the third transistor and one of a source and a drain of the fourth transistor; 
 a gate of the second transistor is electrically connected to one a first electrode of the capacitor; 
 the othera second electrode of the capacitor is directlyelectrically connected to the other of the source and the drain of the fourth transistor and a first terminal of the load; 
 the second electrode of the capacitor is electrically connected to the light-emitting element; 
 the other electrode of the capacitor is not directly connected to any other transistor other than the fourth transistor; 
 the other of the source and the drain of the third transistor is electrically connected to the second line; and a signal line  
 a second terminal of the load is electrically connected to the third line 
 one of a source and a drain of the fifth transistor is electrically connected to the gate of the second transistor; 
 the other of the source and the drain of the fifth transistor is electrically connected to the one of the source and the drain of the first transistor; 
 the first transistor, the second transistor, the third transistor, the fourth transistor and the fifth transistor each have a channel length direction defined as a direction of a shortest path between a source of the transistor and a drain of the transistor, and 
 the first transistor, the second transistor, the third transistor, the fourth transistor, and the fifth transistor are configured such that the first transistor, the second transistor, the third transistor, the fourth transistor and the fifth transistor have a same channel length direction. 
 
 
     
     
       2. The display module according to  claim 1 , further comprising a fifth transistor, wherein:
 the one of the source and the drain of the second transistor is electrically connected to one of a source and a drain of the fifth transistor; and   the gate of the second transistor is electrically connected to the other of the source and the drain of the fifth transistor.   
     
     
       3. The display module according to  claim 1 , wherein the load is a display element having a rectification property. 
     
     
       4. The display module according to  claim 1 , wherein the second line is a signal line. 
     
     
       5. The display module according to  claim 1 , wherein the first line is a power supply line. 
     
     
       6. The display module according to  claim 1 , wherein the third line is a cathode line. 
     
     
       7. A display device comprising the display module according to  claim 1 . 
     
     
       8. An electronic device comprising the display module according to  claim 1 . 
     
     
       9. A display module comprising:
 a display panel comprising: a semiconductor device pixel comprising:
 a first transistor; 
 a second transistor; 
 a third transistor; 
 a fourth transistor; 
 a fifth transistor; 
 a capacitor; and 
 a load light-emitting element; and  
 a first line; 
 a second line; and 
 a third line; and 
   at least one of flexible printed circuit and printed circuit,   
 wherein:
 one of a source and a drain of the first transistor is electrically connected to the first power supply line; 
 one of a source and a drain of the second transistor is electrically connected to the other of the source and the drain of the first transistor; 
 the other of the source and the drain of the second transistor is electrically connected to one of a source and a drain of the third transistor and one of a source and a drain of the fourth transistor; 
 a gate of the second transistor is electrically connected to one a first electrode of the capacitor; 
 the othera second electrode of the capacitor is directlyelectrically connected to the other of the source and the drain of the fourth transistor and a first terminal of the load; 
 the second electrode of the capacitor is electrically connected to the light-emitting element; 
 the other electrode of the capacitor is not directly connected to any other transistor other than the fourth transistor; 
 the other of the source and the drain of the third transistor is electrically connected to the second signal line; 
 one of a source and a drain of the fifth transistor is electrically connected to the gate of the second transistor; 
 the other of the source and the drain of the fifth transistor is electrically connected to the one of the source and the drain of the first transistor; and 
 a second terminal of the load is electrically connected to the third line; and 
 each of the first transistor, the second transistor, the third transistor and the fourth the fifth transistor includes comprises a channel formation region containing comprising an oxide semiconductor. 
 
 
     
     
       10. The display module according to  claim 9 , further comprising a fifth transistor, wherein:
 the one of the source and the drain of the second transistor is electrically connected to one of a source and a drain of the fifth transistor; and   the gate of the second transistor is electrically connected to the other of the source and the drain of the fifth transistor.   
     
     
       11. The display module according to  claim 9 , wherein the load is a display element having a rectification property. 
     
     
       12. The display module according to  claim 9 , wherein the second line is a signal line. 
     
     
       13. The display module according to  claim 9 , wherein the first line is a power supply line. 
     
     
       14. The display module according to  claim 9 , wherein the third line is a cathode line. 
     
     
       15. A display device comprising the display module according to  claim 9 . 
     
     
       16. An electronic device comprising the display module according to  claim 9 . 
     
     
       17. A display module comprising:
 a display panel comprising:
 a pixel comprising:
 a first transistor; 
 a second transistor; 
 a third transistor; 
 a fourth transistor; 
 a fifth transistor; 
 a first capacitor; 
 a second capacitor; and 
 a light-emitting element; and 
 
 at least one of flexible printed circuit and printed circuit, 
   wherein:
 one of a source and a drain of the first transistor is electrically connected to a power supply line; 
 one of a source and a drain of the second transistor is electrically connected to the other of the source and the drain of the first transistor; 
 the other of the source and the drain of the second transistor is electrically connected to one of a source and a drain of the third transistor and one of a source and a drain of the fourth transistor; 
 a gate of the second transistor is electrically connected to a first electrode of the first capacitor; 
 a second electrode of the first capacitor is electrically connected to the other of the source and the drain of the fourth transistor; 
 the second electrode of the first capacitor is electrically connected to the light-emitting element; 
 a first electrode of the second capacitor is electrically connected to the second electrode of the first capacitor, 
 the other of the source and the drain of the third transistor is electrically connected to a signal line; 
 one of a source and a drain of the fifth transistor is electrically connected to the gate of the second transistor; and 
 the other of the source and the drain of the fifth transistor is electrically connected to the one of the source and the drain of the first transistor. 
   
     
     
       18. The display panel according to claim 17,
 wherein a second electrode of the second capacitor is electrically connected to a cathode line.   
     
     
       19. An electronic device comprising the display module according to claim 17.