Abstract: To provide a display device in which parasitic capacitance between wirings can be reduced while preventing increase in wiring resistance. To provide a display device with improved display quality. To provide a display device with low power consumption. A pixel of the liquid crystal display device includes a signal line, a scan line intersecting with the signal line, a first electrode projected from the signal line, a second electrode facing the first electrode, and a pixel electrode connected to the second electrode. Part of the scan line has a loop shape, and part of the first electrode is located in a region overlapped with an opening of the scan line. In other words, part of the first electrode is not overlapped with the scan line.

Abstract: A minute current measurement method is provided. In the current measurement method, a first potential is applied to a first terminal of a transistor under test, a second potential is applied to a first terminal of a first transistor, the first transistor is turned on to accumulate a predetermined charge in a node electrically connecting a second terminal of the transistor under test with a second terminal of the first transistor, a third potential of an output terminal of a read circuit electrically connected to the node is measured, the first transistor is turned off, a fourth potential of the output terminal of the read circuit electrically connected to the node is measured, the amount of the charge held by the node is estimated from the amount of change in the potential of the output terminal of the read circuit (e.g.

Abstract: An object is to obtain a semiconductor device having a high sensitivity in detecting signals and a wide dynamic range, using a thin film transistor in which an oxide semiconductor layer is used. An analog circuit is formed with the use of a thin film transistor including an oxide semiconductor which has a function as a channel formation layer, has a hydrogen concentration of 5×1019 atoms/cm3 or lower, and substantially functions as an insulator in the state where no electric field is generated. Thus, a semiconductor device having a high sensitivity in detecting signals and a wide dynamic range can be obtained.

Abstract: A color sensor with a plurality of optical sensors in which the number of terminals for connection with the outside can be reduced. The color sensor includes a plurality of optical sensors each provided with a photoelectric conversion element and an optical filter over a light-transmitting substrate. The optical filters in the plurality of optical sensors have light-transmitting characteristics different from each other. The plurality of optical sensors is mounted over an interposer including a plurality of terminal electrodes for electrical connection with an external device. The interposer includes a wiring having a plurality of branches for electrical connection between the terminal electrode for inputting a high power supply potential to the plurality of optical sensors and a wiring having a plurality of branches for electrical connection between the terminal electrode for inputting a low power supply potential to the plurality of optical sensors.

Abstract: In a semiconductor device, power consumption is reduced. Further, a standby circuit is formed of a few elements, and thus increase in the circuit area of the semiconductor device is prevented. The standby circuit provided in the semiconductor device is formed of only one transistor and voltage supplied to the transistor is switched, whereby output current of the semiconductor device is controlled. As a result, the output current of the semiconductor device in a standby state can be substantially zero, so that the power consumption can be reduced. By using an oxide semiconductor for a semiconductor layer of a transistor, leakage current can be suppressed as low as possible.

Abstract: To provide a display device in which parasitic capacitance between wirings can be reduced while preventing increase in wiring resistance. To provide a display device with improved display quality. To provide a display device with low power consumption. A pixel of the liquid crystal display device includes a signal line, a scan line intersecting with the signal line, a first electrode projected from the signal line, a second electrode facing the first electrode, and a pixel electrode connected to the second electrode. Part of the scan line has a loop shape, and part of the first electrode is located in a region overlapped with an opening of the scan line. In other words, part of the first electrode is not overlapped with the scan line.

Abstract: An object is to obtain a semiconductor device having a high sensitivity in detecting signals and a wide dynamic range, using a thin film transistor in which an oxide semiconductor layer is used. An analog circuit is formed with the use of a thin film transistor including an oxide semiconductor which has a function as a channel formation layer, has a hydrogen concentration of 5×1019 atoms/cm3 or lower, and substantially functions as an insulator in the state where no electric field is generated. Thus, a semiconductor device having a high sensitivity in detecting signals and a wide dynamic range can be obtained.

Abstract: To provide a display device in which parasitic capacitance between wirings can be reduced while preventing increase in wiring resistance. To provide a display device with improved display quality. To provide a display device with low power consumption. A pixel of the liquid crystal display device includes a signal line, a scan line intersecting with the signal line, a first electrode projected from the signal line, a second electrode facing the first electrode, and a pixel electrode connected to the second electrode. Part of the scan line has a loop shape, and part of the first electrode is located in a region overlapped with an opening of the scan line. In other words, part of the first electrode is not overlapped with the scan line.

Abstract: To provide a display device in which parasitic capacitance between wirings can be reduced while preventing increase in wiring resistance. To provide a display device with improved display quality. To provide a display device with low power consumption. A pixel of the liquid crystal display device includes a signal line, a scan line intersecting with the signal line, a first electrode projected from the signal line, a second electrode facing the first electrode, and a pixel electrode connected to the second electrode. Part of the scan line has a loop shape, and part of the first electrode is located in a region overlapped with an opening of the scan line. In other words, part of the first electrode is not overlapped with the scan line.

Abstract: To provide a display device in which parasitic capacitance between wirings can be reduced while preventing increase in wiring resistance. To provide a display device with improved display quality. To provide a display device with low power consumption. A pixel of the liquid crystal display device includes a signal line, a scan line intersecting with the signal line, a first electrode projected from the signal line, a second electrode facing the first electrode, and a pixel electrode connected to the second electrode. Part of the scan line has a loop shape, and part of the first electrode is located in a region overlapped with an opening of the scan line. In other words, part of the first electrode is not overlapped with the scan line.

Abstract: A novel semiconductor device or memory device is provided. Alternatively, a semiconductor device or memory device in which storage capacity per unit area is large is provided. The semiconductor device includes a sense amplifier provided to a semiconductor substrate and a memory cell provided over the sense amplifier. The sense amplifier includes a first transistor. The memory cell includes a capacitor over the semiconductor substrate, a second transistor provided over the capacitor, a conductor, and a groove portion. The capacitor includes a first electrode and a second electrode. The first electrode is formed along the groove portion. The second electrode has a region facing the first electrode in the groove portion. The second transistor includes an oxide semiconductor. One of a source and a drain of the second transistor is electrically connected to the second electrode through the conductor.

Abstract: A shift register circuit including a logic circuit capable of controlling the threshold voltage of a transistor and outputting a signal corresponding to an input signal by changing only the potential of a back gate without changing the potential of a gate is provided. In a shift register circuit including a logic circuit with a first transistor and a second transistor having the same conductivity type, a first gate electrode of the first transistor is connected to a source electrode or a drain electrode of the first transistor, an input signal is supplied to a second gate electrode of the first transistor, a clock signal is supplied to a gate electrode of the second transistor, and the first gate electrode and the gate electrode are formed from the same layer.

Abstract: An object is to obtain a semiconductor device having a high sensitivity in detecting signals and a wide dynamic range, using a thin film transistor in which an oxide semiconductor layer is used. An analog circuit is formed with the use of a thin film transistor including an oxide semiconductor which has a function as a channel formation layer, has a hydrogen concentration of 5×1019 atoms/cm3 or lower, and substantially functions as an insulator in the state where no electric field is generated. Thus, a semiconductor device having a high sensitivity in detecting signals and a wide dynamic range can be obtained.

Abstract: An object is to obtain a semiconductor device having a high sensitivity in detecting signals and a wide dynamic range, using a thin film transistor in which an oxide semiconductor layer is used. An analog circuit is formed with the use of a thin film transistor including an oxide semiconductor which has a function as a channel formation layer, has a hydrogen concentration of 5×1019 atoms/cm3 or lower, and substantially functions as an insulator in the state where no electric field is generated. Thus, a semiconductor device having a high sensitivity in detecting signals and a wide dynamic range can be obtained.

Abstract: To provide an imaging device in which incident light can be converted into an appropriate electric signal. The imaging device includes a photoelectric conversion element, a first transistor, a second transistor, a third transistor, and a fourth transistor. One of a source electrode and a drain electrode of the first transistor and one electrode of the photoelectric conversion element have an electrical connection portion in a first opening provided in an insulating layer positioned between the one of the source electrode and the drain electrode of the first transistor and the one electrode of the photoelectric conversion element. The number of the first opening is one in a region where the one of the source electrode and the drain electrode of the first transistor overlaps with the one electrode of the photoelectric conversion element.

Abstract: An object is to obtain a semiconductor device having a high sensitivity in detecting signals and a wide dynamic range, using a thin film transistor in which an oxide semiconductor layer is used. An analog circuit is formed with the use of a thin film transistor including an oxide semiconductor which has a function as a channel formation layer, has a hydrogen concentration of 5×1019 atoms/cm3 or lower, and substantially functions as an insulator in the state where no electric field is generated. Thus, a semiconductor device having a high sensitivity in detecting signals and a wide dynamic range can be obtained.

Abstract: A protection circuit used for a semiconductor device is made to effectively function and the semiconductor device is prevented from being damaged by a surge. A semiconductor device includes a terminal electrode, a protection circuit, an integrated circuit, and a wiring electrically connecting the terminal electrode, the protection circuit, and the integrated circuit. The protection circuit is provided between the terminal electrode and the integrated circuit. The terminal electrode, the protection circuit, and the integrated circuit are connected to one another without causing the wiring to branch. It is possible to reduce the damage to the semiconductor device caused by electrostatic discharge. It is also possible to reduce faults in the semiconductor device.

Abstract: To provide a photoelectric conversion device with low power consumption and a method for operating the photoelectric conversion device. The photoelectric conversion device includes a charge storage capacitor portion, a photodiode, and a plurality of transistors. The charge storage capacitor portion is charged after being reset. Then, the charge storage capacitor portion is discharged through the photodiode or a current mirror circuit connected to the photodiode for a given period of time, and after that, the potential of the charge storage capacitor portion is read. Since power is consumed only at the time of charging, power consumption can be reduced.

Abstract: In a semiconductor device, power consumption is reduced. Further, a standby circuit is formed of a few elements, and thus increase in the circuit area of the semiconductor device is prevented. The standby circuit provided in the semiconductor device is formed of only one transistor and voltage supplied to the transistor is switched, whereby output current of the semiconductor device is controlled. As a result, the output current of the semiconductor device in a standby state can be substantially zero, so that the power consumption can be reduced. By using an oxide semiconductor for a semiconductor layer of a transistor, leakage current can be suppressed as low as possible.

Abstract: A minute current measurement method is provided. In the current measurement method, a first potential is applied to a first terminal of a transistor under test, a second potential is applied to a first terminal of a first transistor, the first transistor is turned on to accumulate a predetermined charge in a node electrically connecting a second terminal of the transistor under test with a second terminal of the first transistor, a third potential of an output terminal of a read circuit electrically connected to the node is measured, the first transistor is turned off, a fourth potential of the output terminal of the read circuit electrically connected to the node is measured, the amount of the charge held by the node is estimated from the amount of change in the potential of the output terminal of the read circuit (e.g.