Abstract: It is an object to provide a photoelectric conversion device whose power consumption and a mounting area are reduced and yield is improved and further to provide a photoelectric conversion device whose number of manufacturing processes and manufacturing cost are reduced. A photoelectric conversion device includes a photoelectric conversion element for outputting photocurrent corresponding to illuminance, and a resistor changing resistance corresponding to illuminance. In the photoelectric conversion device, one terminal of the photoelectric conversion element and one terminal of the resistor are electrically connected in series; the other terminal of the photoelectric conversion element is connected to a high power supply potential; the other terminal of the resistor is connected to a low power supply potential; and a light intensity adjusting unit is provided on a light reception surface side of the photoelectric conversion element or the resistor to adjust illuminance.

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: In a semiconductor device, where, with respect to a parasitic resistor in a current mirror circuit, a compensation resistor for compensating the parasitic resistor is provided in the current mirror circuit, the current mirror circuit includes at least two thin film transistors. The thin film transistors each have an island-shaped semiconductor film having a channel formation region and source or drain regions, a gate insulating film, a gate electrode, and source or drain electrodes, and the compensation resistor compensates the parasitic resistor of any one of the gate electrode, the source electrode, and the drain electrode. In addition, each compensation resistor has a conductive layer containing the same material as the gate electrode, the source or drain electrodes, or the source or drain regions.

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: A plurality of transistors in which ratios of a channel length L to a channel width W, ?=W/L, are different from each other is provided in parallel as output side transistors 105a to 105c in a current mirror circuit 101 which amplifies a photocurrent of a photoelectric conversion device and an internal resistor is connected to each of the output side transistors 105a to 105c in series. The sum of currents which flow through the plurality of transistors and the internal resistor is output, whereby a transistor with large amount of ? can be driven in a linear range with low illuminance, and a transistor with small amount of ? can be driven in a linear range with high illuminance, so that applicable illuminance range of the photoelectric conversion device can be widened.

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 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: 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: 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 prevent light leakage caused due to misregistration even when the width of a black matrix layer is not expanded to a designed value or larger. One embodiment of the present invention is a semiconductor device including a single-gate thin film transistor in which a first semiconductor layer is sandwiched between a bottom-gate electrode and a first black matrix layer. The first semiconductor layer and the first black matrix layer overlap with each other.

Abstract: An output terminal of a photoelectric conversion element included in the photoelectric conversion device is connected to a drain terminal and a gate terminal of a MOS transistor which is diode-connected, and a voltage Vout generated at the gate terminal of the MOS transistor is detected in accordance with a current Ip which is generated at the photoelectric conversion element. The voltage Vout generated at the gate terminal of the MOS transistor can be directly detected, so that the range of output can be widened than a method in which an output voltage is converted into a current by connecting a load resistor, and so on.

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: In a photoelectric conversion device including a photodiode and a current mirror circuit, a diode-connected transistor is provided in parallel with the photodiode. The transistor serves as a leakage path for rapidly discharging charge stored in the gate capacitance in the current mirror circuit. Thus, the response speed of the photoelectric conversion device is increased, and output of an abnormal value is reduced.

Abstract: A fuel tank for a vehicle is made of a cast aluminum alloy and has good ductility and toughness. The cast aluminum alloy is subjected to a heat treatment at a temperature of no less than about 350° C. and no more than about 390° C. to possess a Vickers hardness of about 70 HV or less.

Abstract: Disclosed is a thin film transistor including: a gate insulating layer covering a gate electrode; a microcrystalline semiconductor region over the gate insulating layer; a pair of amorphous semiconductor region over the microcrystalline semiconductor; a pair of impurity semiconductor layers over the amorphous semiconductor regions; and wirings over the impurity semiconductor layers. The microcrystalline semiconductor region has a surface having a projection and depression on the gate insulating layer side. The microcrystalline semiconductor region includes a first microcrystalline semiconductor region which is not covered with the amorphous regions and a second microcrystalline semiconductor region which is in contact with the amorphous semiconductor regions. A thickness d1 of the first microcrystalline semiconductor region is smaller than a thickness d2 of the second microcrystalline semiconductor region and d1 is greater than or equal to 30 nm.

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: 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: A semiconductor device including a first element including a photodiode and an amplifier circuit which amplifies output current of the photodiode, over a first insulating film; and a second element including a color filter and an overcoat layer over the color filter over a second insulating film is manufactured. The first element and the second element are attached to each other by bonding the first insulating film and the second insulating film with a bonding material. Further, the amplifier circuit is a current mirror circuit including a thin film transistor. Still further, a color film may be used instead of a color filter.