Patent ID: 11887553
Assignee: SEMICONDUCTOR ENERGY LABORATORY CO., LTD.
Field: Optics (Instruments)
Classification: CPC G  H | IPC G  H

Claim 5:
6. A display device comprising:
a pixel portion comprising a transistor and a pixel electrode electrically connected to the transistor; and
a gate line driver circuit electrically connected to a gate electrode of the transistor,
wherein the transistor comprises a first oxide semiconductor layer over the gate electrode and a second oxide semiconductor layer over the first oxide semiconductor layer,
wherein the second oxide semiconductor layer comprises a c-axis aligned crystalline region,
wherein the pixel portion is configured to display a still image in a first period,
wherein the pixel portion is configured to display a moving image in a second period,
wherein a frequency of writing image signals to the pixel electrode in the first period is lower than a frequency of writing image signals to the pixel electrode in the second period,
wherein the image signals are written to the pixel electrode through the transistor,
wherein the first period comprises a period in which supply of a start pulse and a clock signal to the gate line driver circuit is stopped, and
wherein the first period comprises a period in which a power supply potential supplied to the gate line driver circuit is changed from a high power supply potential to a low power supply potential.