Display device
An object is to provide a display device that performs accurate display. A circuit is formed using a transistor that includes an oxide semiconductor and has a low off-state current. A precharge circuit or an inspection circuit is formed in addition to a pixel circuit. The off-state current is low because the oxide semiconductor is used. Thus, it is not likely that a signal or voltage is leaked in the precharge circuit or the inspection circuit to cause defective display. As a result, a display device that performs accurate display can be provided.
1. A display device comprising:
a pixel portion including a plurality of pixels; and
an inspection circuit configured to inspect whether a second transistor is operating normally or not,
wherein the inspection circuit includes a plurality of first transistors,
wherein each of the plurality of pixels includes the second transistor and a display element,
wherein each of the plurality of first transistors and the second transistor includes an oxide semiconductor, and
wherein an off-state current per channel width of 1 μm of each of the plurality of first transistors and the second transistor is 10 zA/μm or less.
2. The display device according to claim 1 , wherein the oxide semiconductor included in the plurality of first transistors and the second transistor is an intrinsic semiconductor.
3. The display device according to claim 1 , wherein the display device is a liquid crystal display device.
4. An electronic device comprising:
the display device according to claim 1 ; and
an operation switch.
5. The display device according to claim 1 , wherein the inspection whether the second transistor is operating normally or not is performed during manufacturing the display device.
6. A display device comprising:
a pixel portion including a plurality of pixels; and
an inspection circuit,
wherein the inspection circuit includes a plurality of first transistors,
wherein each of the plurality of pixels includes a second transistor and a display element,
wherein gates of the plurality of first transistors are electrically connected to each other,
wherein first terminals of the plurality of first transistors are electrically connected to each other,
wherein all of second terminals of the plurality of first transistors are electrically connected to the pixel portion,
wherein the gates of the plurality of first transistors are in a floating state,
wherein each of the plurality of first transistors and the second transistor includes an oxide semiconductor, and
wherein an off-state current per channel width of 1 μm of each of the plurality of first transistors and the second transistor is 10 zA/μm or less.
7. The display device according to claim 6 , wherein the oxide semiconductor included in the plurality of first transistors and the second transistor is an intrinsic semiconductor.
8. The display device according to claim 6 , wherein the display device is a liquid crystal display device.
9. An electronic device comprising:
the display device according to claim 6 ; and
an operation switch.
10. A display device comprising:
a pixel portion including a plurality of pixels; and
an inspection circuit,
wherein the inspection circuit includes a plurality of first transistors,
wherein each of the plurality of pixels includes a second transistor and a display element,
wherein gates of the plurality of first transistors are electrically connected to each other,
wherein first terminals of the plurality of first transistors are electrically connected to each other,
wherein all of second terminals of the plurality of first transistors are electrically connected to the pixel portion,
wherein the first terminals of the plurality of first transistors are in a floating state,
wherein each of the plurality of first transistors and the second transistor includes an oxide semiconductor, and
wherein an off-state current per channel width of 1 μm of each of the plurality of first transistors and the second transistor is 10 zA/μm or less.
11. The display device according to claim 10 , wherein the oxide semiconductor included in the plurality of first transistors and the second transistor is an intrinsic semiconductor.
12. The display device according to claim 10 , wherein the display device is a liquid crystal display device.
13. An electronic device comprising:
the display device according to claim 10 ; and
an operation switch.
14. A display device comprising:
a pixel portion including a plurality of pixels; and
an inspection circuit configured to inspect whether a second transistor is operating normally or not,
wherein the inspection circuit includes a plurality of first transistors,
wherein each of the plurality of pixels includes the second transistor and a display element,
wherein each of the plurality of first transistors and the second transistor includes an intrinsic oxide semiconductor, and
wherein at least one of a gate or a first terminal of the plurality of first transistors is in a floating state.
15. The display device according to claim 14 , wherein the display device is a liquid crystal display device.
16. An electronic device comprising:
the display device according to claim 14 ; and
an operation switch.
17. The display device according to claim 14 ,
wherein gates of the plurality of first transistors are electrically connected to each other,
wherein first terminals of the plurality of first transistors are electrically connected to each other,
wherein all of second terminals of the plurality of first transistors are electrically connected to the pixel portion, and
wherein the gates of the plurality of first transistors are in a floating state.
18. The display device according to claim 14 ,
wherein gates of the plurality of first transistors are electrically connected to each other,
wherein first terminals of the plurality of first transistors are electrically connected to each other,
wherein all of second terminals of the plurality of first transistors are electrically connected to the pixel portion, and
wherein the first terminals of the plurality of first transistors are in a floating state.