Abstract: To provide a semiconductor device having a high aperture ratio and including a capacitor with a high charge capacitance. To provide a semiconductor device with a narrow bezel. A transistor over a substrate; a first conductive film over a surface over which a gate electrode of the transistor is provided; a second conductive film over a surface over which a pair of electrodes of the transistor is provided; and a first light-transmitting conductive film electrically connected to the first conductive film and the second conductive film are included. The second conductive film overlaps the first conductive film with a gate insulating film of the transistor laid between the second conductive film and the first conductive film.

Abstract: An object is to reduce leakage current and parasitic capacitance of a transistor used for an LSI, a CPU, or a memory. A semiconductor integrated circuit such as an LSI, a CPU, or a memory is manufactured using a thin film transistor in which a channel fog nation region is formed using an oxide semiconductor which becomes an intrinsic or substantially intrinsic semiconductor by removing impurities which serve as electron donors (donors) from the oxide semiconductor and has larger energy gap than that of a silicon semiconductor. With use of a thin film transistor using a highly purified oxide semiconductor layer with sufficiently reduced hydrogen concentration, a semiconductor device with low power consumption due to leakage current can be realized.

Abstract: The following semiconductor device provides high reliability and a narrower frame width. The semiconductor device includes a driver circuit and a pixel portion. The driver circuit has a first transistor including a first gate and a second gate electrically connected to each other with a semiconductor film sandwiched therebetween, and a second transistor electrically connected to the first transistor. The pixel portion includes a third transistor, a liquid crystal element, and a capacitor. The liquid crystal element includes a first transparent conductive film electrically connected to the third transistor, a second conductive film, and a liquid crystal layer. The capacitor includes the first conductive film, a third transparent conductive film, and a nitride insulating film. The nitride insulating film is positioned between the first transparent conductive film and the third transparent conductive film, and positioned between the semiconductor film and the second gate of the first transistor.

Abstract: Provided is a novel display panel which is highly convenient or reliable or a driving method thereof. The display panel includes a first display element, a first conductive film electrically connected to the first display element, a second conductive film having a region overlapping with the first conductive film, an insulating film having a region sandwiched between the second conductive film and the first conductive film, a pixel circuit electrically connected to the second conductive film, and a second display element electrically connected to the pixel circuit. The insulating film has an opening. The second conductive film is electrically connected to the first conductive film in the opening.

Abstract: An object is to provide a memory device including a memory element that can be operated without problems by a thin film transistor with a low off-state current. Provided is a memory device in which a memory element including at least one thin film transistor that includes an oxide semiconductor layer is arranged as a matrix. The thin film transistor including an oxide semiconductor layer has a high field effect mobility and low off-state current, and thus can be operated favorably without problems. In addition, the power consumption can be reduced. Such a memory device is particularly effective in the case where the thin film transistor including an oxide semiconductor layer is provided in a pixel of a display device because the memory device and the pixel can be formed over one substrate.

Abstract: Two gate drivers each comprising a shift register and a demultiplexer including single conductivity type transistors are provided on left and right sides of a pixel portion. Gate lines are alternately connected to the left-side and right-side gate drivers in every M rows. The shift register includes k first unit circuits connected in cascade. The demultiplexer includes k second unit circuits to each of which a signal is input from the first unit circuit and to each of which M gate lines are connected. The second unit circuit selects one or more wirings which output an input signal from the first unit circuit among M gate lines, and outputs the signal from the first unit circuit to the selected wiring(s). Since gate signals can be output from an output of a one-stage shift register to the M gate lines, the width of the shift register can be narrowed.

Abstract: To provide a semiconductor device having a high aperture ratio and including a capacitor with a high charge capacitance. To provide a semiconductor device with a narrow bezel. A transistor over a substrate; a first conductive film over a surface over which a gate electrode of the transistor is provided; a second conductive film over a surface over which a pair of electrodes of the transistor is provided; and a first light-transmitting conductive film electrically connected to the first conductive film and the second conductive film are included. The second conductive film overlaps the first conductive film with a gate insulating film of the transistor laid between the second conductive film and the first conductive film.

Abstract: Provided is a display device with high resolution, high display quality, or high aperture ratio. A pixel includes three subpixels and is electrically connected to two gate lines. One of the gate lines is electrically connected to a gate of a transistor included in each of the two subpixels, and the other gate line is electrically connected to a gate of a transistor included in the other subpixel. Display elements of the three subpixels are arranged in the same direction. Three pixel electrodes of the three subpixels are arranged in the same direction.

Abstract: An object is to reduce leakage current and parasitic capacitance of a transistor used for an LSI, a CPU, or a memory. A semiconductor integrated circuit such as an LSI, a CPU, or a memory is manufactured using a thin film transistor in which a channel formation region is formed using an oxide semiconductor which becomes an intrinsic or substantially intrinsic semiconductor by removing impurities which serve as electron donors (donors) from the oxide semiconductor and has larger energy gap than that of a silicon semiconductor. With use of a thin film transistor using a highly purified oxide semiconductor layer with sufficiently reduced hydrogen concentration, a semiconductor device with low power consumption due to leakage current can be realized.

Abstract: A semiconductor device includes first and second transistors having the same conductivity type and a circuit. One of a source and a drain of the first transistor is electrically connected to that of the second transistor. First and third potentials are supplied to the circuit through respective wirings. A second potential and a first clock signal are supplied to the others of the sources and the drains of the first and second transistors, respectively. A second clock signal is supplied to the circuit. The third potential is higher than the second potential which is higher than the first potential. A fourth potential is equal to or higher than the third potential. The first clock signal alternates the second and fourth potentials and the second clock signal alternates the first and third potentials. The circuit controls electrical connections between gates of the first and second transistors and the wirings.

Abstract: To provide a semiconductor device including a narrowed bezel obtained by designing a gate driver circuit. A gate driver of a display device includes a shift register unit, a demultiplexer circuit, and n signal lines. By connecting the n signal lines for transmitting clock signals to one stage of the shift register unit, (n?3) output signals can be output. The larger n becomes, the smaller the rate of signal lines for transmitting clock signals which do not contribute to output becomes; accordingly, the area of the shift register unit part is small compared to a conventional structure in which one stage of a shift register unit outputs one output signal. Therefore, the gate driver circuit can have a narrow bezel.

Abstract: An input/output device is provided. The input/output device includes a first pixel electrode, a second pixel electrode, a first common electrode, a second common electrode, a liquid crystal, a first insulating film, a second insulating film, and a transistor. The first common electrode can serve as one electrode of a sensor element. The second common electrode can serve as the other electrode of the sensor element. The transistor includes a first gate, a second gate, and a semiconductor layer. The pixel electrode, the common electrodes, and the second gate are positioned on different planes. The second gate contains one or more kinds of metal elements included in the semiconductor layer. The second gate, the pixel electrode, and the common electrodes preferably contain one or more kinds of metal elements included in the semiconductor layer.

Abstract: A reflective region where display is performed with reflection of incident light through a liquid crystal layer and a transmissive region where display is performed by transmission of light from a backlight are provided, and the reflective mode and the transmissive mode are switched. In the case of displaying a full-color image, a pixel portion includes at least a first region and a second region, a plurality of lights of different hues are sequentially supplied to the first region according to a first order, and a plurality of lights of different hues are also sequentially supplied to the second region according to a second order which is different from the first order. In the transmissive mode, the reflective region is made to display black, so that decrease in contrast due to reflection of external light at the reflective region is prevented.

Abstract: A display device includes a plurality of pulse output circuits each of which outputs signals to one of the two kinds of scan lines and a plurality of inverted pulse output circuits each of which outputs, to the other of the two kinds of scan lines, inverted or substantially inverted signals of the signals output from the pulse output circuits. Each of the plurality of inverted pulse output circuits operates with at least two kinds of signals used for the operation of the plurality of pulse output circuits. Thus, through current generated in the inverted pulse output circuits can be reduced.

Abstract: The following semiconductor device provides high reliability and a narrower frame width. The semiconductor device includes a driver circuit and a pixel portion. The driver circuit has a first transistor including a first gate and a second gate electrically connected to each other with a semiconductor film sandwiched therebetween, and a second transistor electrically connected to the first transistor. The pixel portion includes a third transistor, a liquid crystal element, and a capacitor. The liquid crystal element includes a first transparent conductive film electrically connected to the third transistor, a second conductive film, and a liquid crystal layer. The capacitor includes the first conductive film, a third transparent conductive film, and a nitride insulating film. The nitride insulating film is positioned between the first transparent conductive film and the third transparent conductive film, and positioned between the semiconductor film and the second gate of the first transistor.

Abstract: To provide a semiconductor device having a high aperture ratio and including a capacitor with a high charge capacitance. To provide a semiconductor device with a narrow bezel. A transistor over a substrate; a first conductive film over a surface over which a gate electrode of the transistor is provided; a second conductive film over a surface over which a pair of electrodes of the transistor is provided; and a first light-transmitting conductive film electrically connected to the first conductive film and the second conductive film are included. The second conductive film overlaps the first conductive film with a gate insulating film of the transistor laid between the second conductive film and the first conductive film.

Abstract: Transistors each include a gate electrode, a gate insulating layer over the gate electrode, an oxide semiconductor layer over the gate insulating layer, and a source electrode and a drain electrode over the oxide semiconductor layer. A driver circuit portion includes first to third wirings formed in the same step as the gate electrode, fourth to sixth wirings formed in the same step as the source electrode and the drain electrode, a seventh wiring formed in the same step as a pixel electrode, a first region where the second wiring intersects with the fifth wiring, and a second region where the third wiring intersects with the sixth wiring. The first wiring is connected to the fourth wiring through the seventh wiring. A distance between the wirings in the second region is longer than that in the first region.

Abstract: An object is to provide a pulse signal output circuit capable of operating stably and a shift register including the pulse signal output circuit. A pulse signal output circuit according to one embodiment of the disclosed invention includes first to tenth transistors. The ratio W/L of the channel width W to the channel length L of the first transistor and W/L of the third transistor are each larger than W/L of the sixth transistor. W/L of the fifth transistor is larger than W/L of the sixth transistor. W/L of the fifth transistor is equal to W/L of the seventh transistor. W/L of the third transistor is larger than W/L of the fourth transistor. With such a structure, a pulse signal output circuit capable of operating stably and a shift register including the pulse signal output circuit can be provided.

Abstract: An object is to provide a memory device including a memory element that can be operated without problems by a thin film transistor with a low off-state current. Provided is a memory device in which a memory element including at least one thin film transistor that includes an oxide semiconductor layer is arranged as a matrix. The thin film transistor including an oxide semiconductor layer has a high field effect mobility and low off-state current, and thus can be operated favorably without problems. In addition, the power consumption can be reduced. Such a memory device is particularly effective in the case where the thin film transistor including an oxide semiconductor layer is provided in a pixel of a display device because the memory device and the pixel can be formed over one substrate.

Abstract: Two gate drivers each comprising a shift register and a demultiplexer including single conductivity type transistors are provided on left and right sides of a pixel portion. Gate lines are alternately connected to the left-side and right-side gate drivers in every M rows. The shift register includes k first unit circuits connected in cascade. The demultiplexer includes k second unit circuits to each of which a signal is input from the first unit circuit and to each of which M gate lines are connected. The second unit circuit selects one or more wirings which output an input signal from the first unit circuit among M gate lines, and outputs the signal from the first unit circuit to the selected wiring(s). Since gate signals can be output from an output of a one-stage shift register to the M gate lines, the width of the shift register can be narrowed.