US 2012/0056861 A1 · SEMICONDUCTOR DEVICE

Abstract

The semiconductor device includes a plurality of photosensors arranged in matrix. The photosensors each include a photoelectric conversion element and an amplifier circuit. A backlight is turned on, an object to be detected is irradiated with light, and the photosensor in a p-th row performs the reset operation and the storage operation. After that, the backlight is turned off, and the photosensor in a (p+1)th row performs the reset operation and the storage operation. Then, the photosensors in all the rows sequentially perform the selection operation. A difference between output signals obtained from the photosensors in adjacent rows is obtained. Using the difference, a captured image of the object is generated and a region where the object exists is detected. The amplifier circuit includes a transistor for holding stored electric charge, in which a channel is formed in an oxide semiconductor layer.

Claims20

Dependent claims

A semiconductor device comprising:

a first photosensor and a second photosensor,
wherein the first photosensor and the second photosensor are adjacent to each other and electrically connected to a wiring,
wherein the first photosensor is configured to perform a first reset operation and a first storage operation when a backlight is turned on,
wherein the second photosensor is configured to perform a second reset operation and a second storage operation when the backlight is turned off,
wherein the first photosensor is configured to perform a first selection operation to output a first output signal to the wiring,
wherein the second photosensor is configured to perform a second selection operation to output a second output signal to the wiring,
wherein the first selection operation and the second selection operation are sequentially performed after the first storage operation and the second storage operation,
wherein each of the first photosensor and the second photosensor comprises a transistor, and
wherein a channel of the transistor comprises an oxide semiconductor layer.

6 more elements

A semiconductor device comprising:

a first photosensor;
a second photosensor;
a first wiring;
a second wiring;
a third wiring;
a fourth wiring;
a fifth wiring;
a sixth wiring;
and
a seventh wiring,
wherein each of the first photosensor and the second photosensor comprises a photoelectric conversion element, a first transistor, a second transistor, and a third transistor,
wherein the first wiring is electrically connected to a first electrode of the photoelectric conversion element of the first photosensor,
wherein the second wiring is electrically connected to a first electrode of the photoelectric conversion element of the second photosensor,
wherein the third wiring is electrically connected to a gate of the first transistor of the first photosensor,
wherein the fourth wiring is electrically connected to a gate of the first transistor of the second photosensor,
wherein the fifth wiring is electrically connected to a gate of the second transistor of the first photosensor,
wherein the sixth wiring is electrically connected to a gate of the second transistor of the second photosensor,
wherein a second electrode of the photoelectric conversion element is electrically connected to a first terminal of the first transistor,
wherein a second terminal of the first transistor is electrically connected to a gate of the third transistor,
wherein a first terminal of the second transistor and a first terminal of the third transistor are electrically connected to each other,
wherein the seventh wiring is electrically connected to a second terminal of the second transistor of the first photosensor and a second terminal of the second transistor of the second photosensor,
wherein the first photosensor is configured to perform a first reset operation by supplying a first potential to the first wiring and a second potential to the third wiring and a first storage operation by supplying a third potential to the first wiring and the second potential to the third wiring when a backlight is turned on,
wherein the second photosensor is configured to perform a second reset operation by supplying the first potential to the second wiring and the second potential to the fourth wiring and a second storage operation by supplying the third potential to the second wiring and the second potential to the fourth wiring when the backlight is turned off,
wherein the first photosensor is configured to perform a first selection operation to output a first output signal to the seventh wiring,
wherein the second photosensor is configured to perform a second selection operation to output a second output signal to the seventh wiring,
wherein the first selection operation and the second selection operation are sequentially performed by sequentially supplying a fourth potential to the fifth wiring and the sixth wiring after the first storage operation and the second storage operation, and
wherein a channel of the first transistor comprises an oxide semiconductor layer.

24 more elements

A semiconductor device comprising:

a first photosensor;
a second photosensor;
a first wiring;
a second wiring;
a third wiring;
a fourth wiring;
and
a fifth wiring,
wherein each of the first photosensor and the second photosensor comprises a photoelectric conversion element, a first transistor, a second transistor, and a third transistor,
wherein the first wiring is electrically connected to a first electrode of the photoelectric conversion element of the first photosensor,
wherein the second wiring is electrically connected to a first electrode of the photoelectric conversion element of the second photosensor,
wherein the third wiring is electrically connected to a gate of the first transistor of the first photosensor,
wherein the fourth wiring is electrically connected to a gate of the first transistor of the second photosensor,
wherein the fifth wiring is electrically connected to a gate of the second transistor of the first photosensor and a gate of the second transistor of the second photo sensor,
wherein a second electrode of the photoelectric conversion element is electrically connected to a first terminal of the first transistor,
wherein a second terminal of the first transistor is electrically connected to a gate of the third transistor,
wherein a first terminal of the second transistor and a first terminal of the third transistor are electrically connected to each other,
wherein the first photosensor is configured to perform a first reset operation by supplying a first potential to the first wiring and a second potential to the third wiring and a first storage operation by supplying a third potential to the first wiring and the second potential to the third wiring when a backlight is turned on,
wherein the second photosensor is configured to perform a second reset operation by supplying the first potential to the second wiring and the second potential to the fourth wiring and a second storage operation by supplying the third potential to the second wiring and the second potential to the fourth wiring when the backlight is turned off,
wherein the first photosensor is configured to perform a first selection operation to output a first output signal,
wherein the second photosensor is configured to perform a second selection operation to output a second output signal,
wherein the first selection operation and the second selection operation are concurrently performed by supplying a fourth potential to the fifth wiring after the first storage operation and the second storage operation, and
wherein a channel of the first transistor comprises an oxide semiconductor layer.

20 more elements

Dependencies are inferred from the claim text.

Semiconductor device

Life of this patent

Semiconductor device

Life of this patent

Abstract

Claims20