Abstract: A display apparatus can include a first thin-film transistor including a first active layer having a first polysilicon material, a first gate electrode overlapping the first active layer, a first electrode and a second electrode; a second thin-film transistor including a second active layer having an oxide semiconductor, a second gate electrode overlapping the second active layer, a third electrode and a fourth electrode; and a first emitting electrode of a light emitting element electrically connected to the second electrode of the first thin-film transistor. Also, one end of the first active layer having the first polysilicon material is electrically connected to one or the other end of the second active layer having the oxide semiconductor.

Abstract: A display apparatus including a first thin-film transistor, a second thin-film transistor and a third thin-film transistor is provided. The first thin-film transistor includes a first active layer composed of a polysilicon material, a first gate electrode overlapping the first active layer such that a first gate insulating layer is interposed therebetween, a first source electrode and a first drain electrode. The first gate electrode includes n layers. The first source electrode and the first drain electrode are connected to the first active layer. The second thin-film transistor includes a second active layer composed of a polysilicon material, a second gate electrode overlapping the second active layer such that a first gate insulating layer is interposed therebetween, a second source electrode and a second drain electrode. The second gate electrode includes n+1 layers. The second source electrode and the second drain electrode are connected to the second active layer.

Abstract: A display apparatus includes an oxide semiconductor pattern disposed on a device substrate and including a channel region disposed between a source region and a drain region, a gate electrode overlapping the channel region of the oxide semiconductor pattern and having a structure in which a first hydrogen barrier layer and a gate conductive layer are stacked, and a gate insulating film disposed between the oxide semiconductor pattern and the gate electrode to expose the source region and the drain region of the oxide semiconductor pattern. The gate electrode exposes a portion of the gate insulating film that is adjacent to the source region and a portion of the gate insulating film that is adjacent to the drain region.

Abstract: A display apparatus includes an oxide semiconductor pattern disposed on a device substrate and including a channel region disposed between a source region and a drain region, a gate electrode overlapping the channel region of the oxide semiconductor pattern and having a structure in which a first hydrogen barrier layer and a gate conductive layer are stacked, and a gate insulating film disposed between the oxide semiconductor pattern and the gate electrode to expose the source region and the drain region of the oxide semiconductor pattern. The gate electrode exposes a portion of the gate insulating film that is adjacent to the source region and a portion of the gate insulating film that is adjacent to the drain region.

Abstract: A display apparatus including a first thin-film transistor, a second thin-film transistor and a third thin-film transistor is provided. The first thin-film transistor includes a first active layer composed of a polysilicon material, a first gate electrode overlapping the first active layer such that a first gate insulating layer is interposed therebetween, a first source electrode and a first drain electrode. The first gate electrode includes n layers. The first source electrode and the first drain electrode are connected to the first active layer. The second thin-film transistor includes a second active layer composed of a polysilicon material, a second gate electrode overlapping the second active layer such that a first gate insulating layer is interposed therebetween, a second source electrode and a second drain electrode. The second gate electrode includes n+1 layers. The second source electrode and the second drain electrode are connected to the second active layer.

Abstract: A display apparatus includes an oxide semiconductor pattern disposed on a device substrate and including a channel region disposed between a source region and a drain region, a gate electrode overlapping the channel region of the oxide semiconductor pattern and having a structure in which a first hydrogen barrier layer and a gate conductive layer are stacked, and a gate insulating film disposed between the oxide semiconductor pattern and the gate electrode to expose the source region and the drain region of the oxide semiconductor pattern. The gate electrode exposes a portion of the gate insulating film that is adjacent to the source region and a portion of the gate insulating film that is adjacent to the drain region.

Abstract: An aluminum head drum for use in a video cassette recorder is coated with a protective layer comprising diamond-like carbon. The protective layer of diamond-like carbon is obtained using a plasma-enhanced chemical vapor deposition method and has a thickness ranging from 0.3 .mu.m to 2.0 .mu.m. The protective layer has a varying mechanical hardness, wherein the mechanical hardness has a maximum value at a region of the protective layer coming in contact with the aluminum head drum, decreases smoothly and continuously and reaches an minimum value at a region of the protective layer coming in contact with atmosphere. Micro-Vicker's hardness of the region of the protective layers coming in contact with a video tape is 1.5-2.0 times that of the magnetic substance constituting the video tape.

Abstract: An image signal recording and reproducing apparatus comprises a head array having a plurality of head gaps for recording and reproducing the image; a piezoelectric actuator having a polarization direction and for moving the head array downwards and upwards in a width direction of a track in accordance with input of a driving voltage; a phase comparator for generating a phase control signal in accordance with a phase difference between the head array and the track; a unit for outputting the driving voltage to the actuator in accordance with the phase control signal; and a signal processing unit for recording and reproducing the image signal on and from the track by the head array.