DISPLAY DEVICE, SEMICONDUCTOR DEVICE, AND DRIVING METHOD THEREOF

1 . (canceled)

2 . A semiconductor device comprising:

a shift register comprising:

a first transistor;

a second transistor;

a third transistor;

a fourth transistor;

a fifth transistor;

a sixth transistor; and

a seventh transistor,

wherein one of a source and a drain of the first transistor is electrically connected to a first line, the other of the source and the drain of the first transistor is electrically connected to a second line,

wherein one of a source and a drain of the second transistor is electrically connected to a third line, the other of the source and the drain of the second transistor is electrically connected to the second line,

wherein one of a source and a drain of the third transistor is electrically connected to the third line,

wherein the other of the source and the drain of the third transistor is electrically connected to the second line,

wherein one of a source and a drain of the fourth transistor is electrically connected to the second line, the other of the source and the drain of the fourth transistor is electrically connected to a gate of the first transistor, a gate of the fourth transistor is electrically connected to a gate of the second transistor,

wherein one of a source and a drain of the fifth transistor is electrically connected to a fourth line,

wherein the other of the source and the drain of the fifth transistor is electrically connected to the gate of the first transistor,

wherein one of a source and a drain of the sixth transistor is electrically connected to the fourth line,

wherein the other of the source and the drain of the sixth transistor is electrically connected to the gate of the first transistor,

wherein one of a source and a drain of the seventh transistor is electrically connected to the third line,

wherein the other of the source and the drain of the seventh transistor is electrically connected to the gate of the first transistor,

wherein a gate of the seventh transistor is electrically connected to a gate of the third transistor,

wherein each channel region of the first transistor, the second transistor, the third transistor, the fourth transistor, the fifth transistor, the sixth transistor, and the seventh transistor includes an oxide semiconductor.

3 . A display device comprising the semiconductor device according to claim 2 .

4 . An electronic appliance comprising the semiconductor device according to claim 2 , the electronic appliance comprising at least one of a speaker, an image reception portion, a sensor, a microphone, an LED lamp, and an antenna.

5 . A semiconductor device comprising:

a first transistor;

a second transistor;

a third transistor;

a fourth transistor;

a fifth transistor;

a sixth transistor; and

a seventh transistor,

wherein one of a source and a drain of the first transistor is electrically connected to a first line, the other of the source and the drain of the first transistor is electrically connected to a second line,

wherein one of a source and a drain of the second transistor is electrically connected to a third line, the other of the source and the drain of the second transistor is electrically connected to the second line,

wherein one of a source and a drain of the third transistor is electrically connected to the third line,

wherein the other of the source and the drain of the third transistor is electrically connected to the second line,

wherein one of a source and a drain of the fourth transistor is electrically connected to the second line, the other of the source and the drain of the fourth transistor is electrically connected to a gate of the first transistor, a gate of the fourth transistor is electrically connected to a gate of the second transistor,

wherein one of a source and a drain of the fifth transistor is electrically connected to a fourth line,

wherein the other of the source and the drain of the fifth transistor is electrically connected to the gate of the first transistor,

wherein one of a source and a drain of the sixth transistor is electrically connected to the fourth line,

wherein the other of the source and the drain of the sixth transistor is electrically connected to the gate of the first transistor,

wherein one of a source and a drain of the seventh transistor is electrically connected to the third line,

wherein the other of the source and the drain of the seventh transistor is electrically connected to the gate of the first transistor,

wherein a gate of the seventh transistor is electrically connected to a gate of the third transistor,

wherein each channel region of the first transistor, the second transistor, the third transistor, the fourth transistor, the fifth transistor, the sixth transistor, and the seventh transistor includes an oxide semiconductor.

6 . The semiconductor device according to claim 5 , wherein each off-state current of at least the first transistor is 1 aA/μm or less.

7 . A display device comprising the semiconductor device according to claim 5 .

8 . An electronic appliance comprising the semiconductor device according to claim 5 , the electronic appliance comprising at least one of a speaker, an image reception portion, a sensor, a microphone, an LED lamp, and an antenna.

9 . A display device comprising the semiconductor device according to claim 5 , wherein the display device comprises:

a gate driver;

a pixel portion;

wherein each of the gate driver and the pixel portion overlaps a same substrate,

wherein the gate driver comprises:

the first transistor;

the second transistor;

the third transistor;

the fourth transistor;

the fifth transistor;

the sixth transistor; and

the seventh transistor,

wherein the pixel portion comprises:

a first pixel; and

a second pixel,

wherein the first pixel is electrically connected to the fourth line, and

wherein the second pixel is electrically connected to the second line.