Display device, and method of operation thereof

A semiconductor device including a pixel portion and a driver circuit portion, the semiconductor device comprising:

• a first substrate;
• a thin film transistor over the first substrate;
• a light emitting element electrically connected to the thin film transistor, wherein the light emitting element comprises:
• a first electrode;
• a light emitting layer over the first electrode, the light emitting layer comprising an organic compound;
• and
• a second electrode over the first electrode so that the light emitting layer is disposed between the first electrode and the second electrode;
• a second substrate over the second electrode;
• a sealing material interposed between the first substrate and the second substrate;
• an insulating film over the second substrate;
• and
• a conductive layer on the insulating film,
• wherein the driver circuit portion includes a control circuit which controls light emission intensity of the light emitting element in accordance with display of a first region of the pixel portion and controls light emission intensity of the light emitting element in accordance with display of a second region,
• wherein a luminance of a highest grayscale in one screen is different between the first region and the second region.

An operating method of a semiconductor device comprising:

• a pixel portion including a light emitting element which performs display based on a video signal;
• a driver circuit portion where the video signal is to be inputted;
• and
• a control circuit for controlling a grayscale in accordance with display of the pixel portion in the driver circuit portion,
• wherein the video signal is inputted to a frame memory included in the control circuit and the video signal for one frame is stored in the frame memory, and
• wherein the light emitting element comprises a first electrode operationally connected to the driver circuit portion and a second electrode with an electroluminescent layer interposed therebetween, comprising the steps of:
• carrying out a process to determine a ratio of a high grayscale region to a low grayscale region based on the video signal for one frame by a determining circuit included in the control circuit;
• and
• carrying out an addition process by a converter circuit included in the control circuit to display the high grayscale region at higher luminance based on a result of the determination process.

An operating method of a semiconductor device comprising:

• a pixel portion including a light emitting element which performs display based on a video signal;
• a driver circuit portion inputted with the video signal;
• and
• a control circuit for controlling a grayscale in accordance with display of the pixel portion in the driver circuit portion,
• wherein the video signal is inputted to a frame memory included in the control circuit and a video signal for one frame is stored in the frame memory, and
• wherein the light emitting element comprises a first electrode operationally connected to the driver circuit portion and a second electrode with an electroluminescent layer interposed therebetween, comprising the steps of:
• carrying out a process to determine a ratio of a high grayscale region to a low grayscale region based on the video signal for one frame by a determining circuit included in the control circuit;
• and
• carrying out a subtraction process by a converter circuit included in the control circuit to decrease luminance of a whole screen based on a result of the determination process.