A thin film transistor (TFT) substrate includes a TFT on the substrate. The TFT includes an active patterned layer which is made of a polycrystalline silicon, which includes a channel portion, a source portion and a drain portion, and in which protrusions are formed at boundaries between grains and recess spaces are formed between the protrusions. A barrier pattern film fills the recess spaces and forms a flat surface with the protrusions. A gate electrode is on a gate insulating layer located on the barrier pattern film and the protrusions and overlays or corresponds to the channel portion. A source electrode and a drain electrode are on the gate electrode and respectively contact the source portion and the drain portion.

A display device includes a substrate including a display area and a non-display area around the display area. A pixel is disposed on the display area. A first dam is disposed on the non-display area. The first dam includes a first sub-dam and a second sub-dam disposed on the first sub-dam. A first power line is disposed on the non-display area and passes between the first sub-dam and the second sub-dam. The first power line is connected to the pixel. A bridge pattern is disposed under the first sub-dam. The bridge pattern is connected to the first power line.

A display device includes a flexible substrate, a plurality of TFTs, a first electrode arranged between a channel of one of the plurality of TFTs and the flexible substrate, at least one inorganic insulating film arranged between one of the plurality of TFTs and the first electrode, a second electrode arranged on the opposite side to the side where one of the plurality of TFTs is arranged with respect to the first electrode, and an organic insulating film arranged between the first electrode and the second electrode.

A display device is disclosed that may include a first active layer disposed on a substrate, a scan line disposed on the first active layer, extending in a first direction and including a first protruding portion protruding in a second direction crossing the first direction, a first compensation control line disposed on the first active layer, extending in the first direction and spaced apart from the scan line in the second direction, and a second active layer disposed on the scan line and the first compensation control line, overlapping the scan line and the first compensation control line and including a second protruding portion protruding in the first direction. The first protruding portion may be positioned outside the second active layer in the first direction in a plan view.

An object is to provide a display device which operates stably with use of a transistor having stable electric characteristics. In manufacture of a display device using transistors in which an oxide semiconductor layer is used for a channel formation region, a gate electrode is further provided over at least a transistor which is applied to a driver circuit. In manufacture of a transistor in which an oxide semiconductor layer is used for a channel formation region, the oxide semiconductor layer is subjected to heat treatment so as to be dehydrated or dehydrogenated; thus, impurities such as moisture existing in an interface between the oxide semiconductor layer and the gate insulating layer provided below and in contact with the oxide semiconductor layer and an interface between the oxide semiconductor layer and a protective insulating layer provided on and in contact with the oxide semiconductor layer can be reduced.

An object is to improve reliability of a light-emitting device. A light-emitting device has a driver circuit portion including a transistor for a driver circuit and a pixel portion including a transistor for a pixel over one substrate. The transistor for the driver circuit and the transistor for the pixel are inverted staggered transistors each including an oxide semiconductor layer in contact with part of an oxide insulating layer. In the pixel portion, a color filter layer and a light-emitting element are provided over the oxide insulating layer. In the transistor for the driver circuit, a conductive layer overlapping with a gate electrode layer and the oxide semiconductor layer is provided over the oxide insulating layer. The gate electrode layer, a source electrode layer, and a drain electrode layer are formed using metal conductive films.

A flexible display device including a substrate, a light emitting layer, a first insulating layer, and a conductive layer. The substrate includes a bent region and a non-bent region. The light emitting layer overlaps the non-bent region. The first insulating layer is disposed on the substrate. The conductive layer is disposed on the first insulating layer. A sidewall of the first insulating layer includes a first tapered surface. The first tapered surface includes at least three curved surface portions continuously arranged with one another.

A display substrate, a preparation method thereof, a display panel, and a display device are provided. The display substrate includes a base substrate and a repeating unit, the repeating unit includes a plurality of sub-pixels including a first sub-pixel and a second sub-pixel, a color of light emitted by a light-emitting element of the first sub-pixel is identical to a color of light emitted by a light-emitting element of the second sub-pixel, a shape of a first light-emitting voltage application electrode of the light-emitting element of the first sub-pixel is different from a shape of a first light-emitting voltage application electrode of the light-emitting element of the second sub-pixel.

The liquid crystal display device includes an island-shaped first semiconductor film 102 which is formed over a base insulating film 101 and in which a source 102d, a channel forming region 102a, and a drain 102b are formed; a first electrode 102c which is formed of a material same as the first semiconductor film 102 to be the source 102d or the drain 102b and formed over the base insulating film 101; a second electrode 108 which is formed over the first electrode 102c and includes a first opening pattern 112; and a liquid crystal 110 which is provided over the second electrode 108.

An object of the invention is to improve the reliability of a light-emitting device. Another object of the invention is to provide flexibility to a light-emitting device having a thin film transistor using an oxide semiconductor film. A light-emitting device has, over one flexible substrate, a driving circuit portion including a thin film transistor for a driving circuit and a pixel portion including a thin film transistor for a pixel. The thin film transistor for a driving circuit and the thin film transistor for a pixel are inverted staggered thin film transistors including an oxide semiconductor layer which is in contact with a part of an oxide insulating layer.