Abstract: In a video voltage comparator circuit, an average of first video voltages applied to pixel electrodes of pixels in the second-half rows in a k-th frame period (k is a natural number) is compared with an average of second video voltages applied to pixel electrodes of pixels in the first-half rows in a (k+1)th frame period for each row. In an overdrive voltage switching circuit, when a difference obtained from the comparison in the video voltage comparator circuit is greater than or equal to a threshold value, the overdrive voltage in the (k+1)th frame period is switched to a first overdrive voltage, and when the difference obtained from the comparison in the video voltage comparator circuit is less than the threshold value, the overdrive voltage in the (k+1)th frame period is switched to a second overdrive voltage lower than the first overdrive voltage.

Abstract: It is an object of the present invention to reduce a cause of pseudo contour when display is performed with a time gray scale method. According to the present invention, one pixel is divided into m sub-pixels so that an area ratio of each sub-pixel becomes 20:21:22: . . . :2m-3:2m-2:2m-1 (m is an integer number of m?2), and one frame is divided into n sub-frames so that a ratio of a lighting period in each sub-frame becomes 20:2m:22m: . . . :2(n-3)m:2(n-2)m:2(n-1)m (n is an integer number of n?2). Then, a gray scale is expressed by controlling a manner of lighting in each of the m sub-pixels in each of the n sub-frames.

Abstract: To provide a semiconductor device including a capacitor whose charge capacity is increased without reducing the aperture ratio. The semiconductor device includes a transistor including a light-transmitting semiconductor film, a capacitor where a dielectric film is provided between a pair of electrodes, an insulating film provided over the light-transmitting semiconductor film, and a light-transmitting conductive film provided over the insulating film. In the capacitor, a metal oxide film containing at least indium (In) or zinc (Zn) and formed on the same surface as the light-transmitting semiconductor film in the transistor serves as one electrode, the light-transmitting conductive film serves as the other electrode, and the insulating film provided over the light-transmitting semiconductor film serves as the dielectric film.

Abstract: An object is to provide a light-emitting display device in which a pixel including a thin film transistor using an oxide semiconductor has a high aperture ratio. The light-emitting display device includes a plurality of pixels each including a thin film transistor and a light-emitting element. The pixel is electrically connected to a first wiring functioning as a scan line. The thin film transistor includes an oxide semiconductor layer over the first wiring with a gate insulating film therebetween. The oxide semiconductor layer is extended beyond the edge of a region where the first wiring is provided. The light-emitting element and the oxide semiconductor layer overlap with each other.

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 light-emitting display device in which a pixel including a thin film transistor using an oxide semiconductor has a high aperture ratio. The light-emitting display device includes a plurality of pixels each including a thin film transistor and a light-emitting element. The pixel is electrically connected to a first wiring functioning as a scan line. The thin film transistor includes an oxide semiconductor layer over the first wiring with a gate insulating film therebetween. The oxide semiconductor layer is extended beyond the edge of a region where the first wiring is provided. The light-emitting element and the oxide semiconductor layer overlap with each other.

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: To provide a display device and a driving method thereof, where variations in the threshold voltage of transistors can be compensated and thus variations in luminance of light-emitting elements can be suppressed. In a first period, initialization is performed; in a second period, a voltage based on the threshold voltage of a first transistor is held in first and second storage capacitors; in a third period, a voltage based on a video signal voltage and the threshold voltage of the first transistor is held in the first and second storage capacitors; and in a fourth period, voltages held in the first and second storage capacitors are applied to a gate terminal of the first transistor to supply a current to a light-emitting element, so that the light-emitting element emits light. Through the operation process, a current obtained by compensating variations in the threshold voltage of the first transistor can be supplied to the light-emitting element, thereby variations in luminance can be suppressed.

Abstract: A novel display panel that is highly convenient or reliable, a novel input/output device that is highly convenient or reliable, or a novel data processor that is highly convenient or reliable is provided. The display panel includes a selection signal line, a first signal line and a second signal line that cross the selection signal line, a first pixel electrically connected to the selection signal line and the first signal line, a second pixel electrically connected to the selection signal line and the second signal line, a first terminal electrically connected to the first signal line, and a second terminal electrically connected to the second signal line.

Abstract: It is an object to provide a display device in which a problem of light leakage from a liquid crystal element in black display is reduced or overcome and the contrast is improved. It is another object to provide a pixel circuit having a function to control a lighting state of a backlight based on each pixel. These objects are achieved by turning off a light-emitting element in display of a black gray scale, and by providing a light-emitting element in each pixel and providing, in a pixel circuit, a function to individually control lighting and non-lighting of the light-emitting element depending on a gray scale to perform display. When a backlight is provided in each pixel, a light-emitting element that is a backlight is turned off when a black gray scale is displayed, whereby reduction in contrast due to light leakage from a liquid crystal element can be prevented.

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 semiconductor device with stable electrical characteristics is provided. The semiconductor device includes an oxide semiconductor film, a first gate electrode, a second gate electrode, a first conductive film, and a second conductive film. The first gate electrode is electrically connected to the second gate electrode. The first conductive film and the second conductive film function as a source electrode and a drain electrode. The oxide semiconductor film includes a first region that overlaps with the first conductive film, a second region that overlaps with the second conductive film, and a third region that overlaps with a gate electrode and the third conductive film. The first region includes a first edge that is opposed to the second region. The second region includes a second edge that is opposed to the first region. The length of the first edge is shorter than the length of the second edge.

Abstract: In a display element such as an organic EL element, deterioration progresses due to light emission, and emission luminance is lowered even if the same voltage is applied to the display element. Therefore, use over time causes variations in luminance of each pixel, thereby a so-called “image burn-in” phenomenon occurs. Given this factor, the invention provides a display device which can reduce the difference in deterioration of a display element in each pixel and suppress variations in light emission of a display element in a pixel. It is prevented that only a specific pixel has a long accumulated lighting time. For that purpose, a gray scale of a display pattern is changed to prevent the difference in deterioration of display element in pixels from increasing. Alternatively, a specific display pattern is prevented from being fixedly displayed in a specific region.

Abstract: Provided is an imaging device that can correct an output value of a pixel circuit. The imaging device includes a pixel circuit, a current detection circuit, an A/D converter, one or more memory circuit portions, and an arithmetic circuit portion. The pixel circuit includes a transistor, a charge accumulation portion, and a light-receiving element. The memory circuit portion includes a first look-up table, a second look-up table, and a region where image data output from the arithmetic circuit portion is stored. The first look-up table stores data of potentials of the charge accumulation portion, which depends on the intensity of light. The second look-up table stores output data of the transistor, which depends on the potentials of the charge accumulation portion.

Abstract: It is an object to provide a display device in which a problem of light leakage from a liquid crystal element in black display is reduced or overcome and the contrast is improved. It is another object to provide a pixel circuit having a function to control a lighting state of a backlight based on each pixel. These objects are achieved by turning off a light-emitting element in display of a black gray scale, and by providing a light-emitting element in each pixel and providing, in a pixel circuit, a function to individually control lighting and non-lighting of the light-emitting element depending on a gray scale to perform display. When a backlight is provided in each pixel, a light-emitting element that is a backlight is turned off when a black gray scale is displayed, whereby reduction in contrast due to light leakage from a liquid crystal element can be prevented.

Abstract: To provide a display device and a driving method thereof, where variations in the threshold voltage of transistors can be compensated and thus variations in luminance of light-emitting elements can be suppressed. In a first period, initialization is performed; in a second period, a voltage based on the threshold voltage of a first transistor is held in first and second storage capacitors; in a third period, a voltage based on a video signal voltage and the threshold voltage of the first transistor is held in the first and second storage capacitors; and in a fourth period, voltages held in the first and second storage capacitors are applied to a gate terminal of the first transistor to supply a current to a light-emitting element, so that the light-emitting element emits light. Through the operation process, a current obtained by compensating variations in the threshold voltage of the first transistor can be supplied to the light-emitting element, thereby variations in luminance can be suppressed.

Abstract: To increase the detection sensitivity of a touch panel, increase the visibility of a touch panel, provide a bendable touch panel, provide a thin touch panel, or provide a lightweight touch panel. The touch sensor has a first substrate, a first conductive layer, a second conductive layer, and an insulating layer. The first conductive layer includes a region between the first substrate and the second conductive layer. The insulating layer includes a region between the first conductive layer and the second conductive layer. The first conductive layer, the second conductive layer, and the insulating layer form a capacitor. The second conductive layer has an opening. The opening in the second conductive layer and the first conductive layer overlap with each other in a region.

Abstract: A flexible input and output device in which defects due to a crack is reduced. The input and output device includes a first flexible substrate, a second flexible substrate, a first buffer layer, a first crack inhibiting layer, an input device, and a light-emitting element. A first surface of the first flexible substrate faces a second surface of the second flexible substrate. The first buffer layer, the first crack inhibiting layer, and the input device are provided on the first surface side of the first flexible substrate. The first buffer layer includes a region overlapping with the first crack inhibiting layer. The first buffer layer is between the first crack inhibiting layer and the first surface. The input device includes a transistor and a sensor element. The light-emitting element is provided on the second surface side of the second flexible substrate.

Abstract: It is an object to provide a display device in which a problem of light leakage from a liquid crystal element in black display is reduced or overcome and the contrast is improved. It is another object to provide a pixel circuit having a function to control a lighting state of a backlight based on each pixel. These objects are achieved by turning off a light-emitting element in display of a black gray scale, and by providing a light-emitting element in each pixel and providing, in a pixel circuit, a function to individually control lighting and non-lighting of the light-emitting element depending on a gray scale to perform display. When a backlight is provided in each pixel, a light-emitting element that is a backlight is turned off when a black gray scale is displayed, whereby reduction in contrast due to light leakage from a liquid crystal element can be prevented.

Abstract: Provided is an electronic device with high portability, a highly browsable electronic device, or an electronic device having a novel light source that can be used in shooting photographs and video. The electronic device includes a camera and a flexible display portion. The display portion has a first region and a second region. The first region has a function of emitting light to a photographic subject. The second region has a function of displaying an image of the photographic subject shot by the camera. The display portion can be bent so that the first region and the second region face in different directions.