Abstract: A novel foldable display device or an electronic device using the same, e.g., a portable information processor or a portable communication information device, is provided. A foldable display device of which a display panel can be folded n times (n?1, and n is a natural number) at a curvature radius of greater than or equal to 1 mm and less than or equal to 100 mm is obtained. The display device can be miniaturized by being foldable. In addition, in the state where the flexible display panel is opened, display which is unbroken and continuous over a plurality of housings is possible. The plurality of housings can store a circuit, an electronic component, a battery and the like inside as appropriate, and the thickness of each housing can be small.

Abstract: By applying an AC pulse to a gate of a transistor which easily deteriorates, a shift in threshold voltage of the transistor is suppressed. However, in a case where amorphous silicon is used for a semiconductor layer of a transistor, the occurrence of a shift in threshold voltage naturally becomes a problem for a transistor which constitutes a part of circuit that generates an AC pulse. A shift in threshold voltage of a transistor which easily deteriorates and a shift in threshold voltage of a turned-on transistor are suppressed by signal input to a gate electrode of the transistor which easily deteriorates through the turned-on transistor. In other words, a structure for applying an AC pulse to a gate electrode of a transistor which easily deteriorates through a transistor to a gate electrode of which a high potential (VDD) is applied, is included.

Abstract: A display device capable of high-quality stereoscopic display without decreasing resolution is provided. A pixel portion including a plurality of pixels arranged in matrix is divided into plural regions, lighting of backlight units each emitting light of different hues is controlled in each region, and the backlight units of the plural regions are turned off simultaneously at a regular interval so as to display black. The right-eye image and the left-eye image are alternately displayed with black display interposed therebetween, and light incident on the right eye of a viewer is blocked when a left-eye image is displayed, and light incident on the left eye of the viewer is blocked when a right-eye image is displayed. An image signal is written into a pixel in a black display period during which the backlight units are turned off.

Abstract: An object is to provide a transistor in which the state of an interface between an oxide semiconductor layer and an insulating film (gate insulating layer) in contact with the oxide semiconductor layer is favorable; and a method for manufacturing the transistor. In order to obtain the transistor, nitrogen is added to a region of the oxide semiconductor layer in the vicinity of the interface with the gate insulating layer. Specifically, a concentration gradient of nitrogen is formed in the oxide semiconductor layer, and a region containing much nitrogen is provided at the interface with the gate insulating layer. By the addition of nitrogen, a region with high crystallinity can be formed in the region of the oxide semiconductor layer in the vicinity of the interface with the gate insulating layer, so that a stable interface state can be obtained.

Abstract: A FET is formed on a semiconductor substrate, a curved surface having a radius of curvature is formed on an upper end of an insulation, a portion of a first electrode is exposed corresponding to the curved surface to form an inclined surface, and a region defining a luminescent region is subjected to etching to expose the first electrode. Luminescence emitted from an organic chemical compound layer is reflected by the inclined surface of the first electrode to increase a total quantity of luminescence taken out in a certain direction.

Abstract: Disclosed is a semiconductor device comprising a thin film transistor and wirings connected to the thin film transistor, in which the thin film transistor has a channel formation region in an oxide semiconductor layer, and a copper metal is used for at least one of a gate electrode, a source electrode, a drain electrode, a gate wiring, a source wiring, and a drain wiring. The extremely low off current of the transistor with the oxide semiconductor layer contributes to reduction in power consumption of the semiconductor device. Additionally, the use of the copper metal allows the combination of the semiconductor device with a display element to provide a display device with high display quality and negligible defects, which results from the low electrical resistance of the wirings and electrodes formed with the copper metal.

Abstract: A method of separating a lamination body with high yield without damaging the lamination body is provided. Further, a method of manufacturing a lightweight, flexible semiconductor device, which is thin in total is provided. The method of manufacturing the semiconductor device includes: a first step of laminating a metal layer, an oxide layer, a layer containing no hydrogen element, and a lamination body on a first substrate; a second step of forming a photocatalytic layer on a transparent substrate; and a third step of attaching the photocatalytic layer to the surface of the lamination body by using a first adhesive material after the first and second steps, separating the metal layer from the oxide layer, and irradiating light from a side of the transparent substrate so that an interface between the photocatalytic layer and the first adhesive material is separated to remove the first adhesive material.