Abstract: A method of fabricating a polycrystalline silicon thin film transistor device includes the following steps. A substrate is provided, and a buffer layer having dopants is formed on the substrate. An amorphous silicon layer is formed on the buffer layer having the dopants. A thermal process is performed to convert the amorphous silicon layer into a polycrystalline silicon layer by means of polycrystalization, and to simultaneously out-diffuse a portion of the dopants in the buffer layer into the polycrystalline silicon layer for adjusting a threshold voltage. The polycrystalline silicon layer is patterned to form an active layer. A gate insulating layer is formed on the active layer. A gate electrode is formed on the gate insulating layer. A source doped region and a drain doped region are formed in the active layer.

Abstract: A method of fabricating a polycrystalline silicon thin film transistor device includes the following steps. A substrate is provided, and a buffer layer having dopants is formed on the substrate. An amorphous silicon layer is formed on the buffer layer having the dopants. A thermal process is performed to convert the amorphous silicon layer into a polycrystalline silicon layer by means of polycrystalization, and to simultaneously out-diffuse a portion of the dopants in the buffer layer into the polycrystalline silicon layer for adjusting a threshold voltage. The polycrystalline silicon layer is patterned to form an active layer. A gate insulating layer is formed on the active layer. A gate electrode is formed on the gate insulating layer. A source doped region and a drain doped region are formed in the active layer.

Abstract: A speed changing apparatus includes a planet gear set having a sun gear, planet pinions, a planet pinion carrier and a ring gear mounted inside a rotary sleeve. The sun gear is driven by a D.C. motor to rotate in either of two opposed rotary directions. Clutch arrangements are operative to lock one of either the carrier arm or the ring gear to a rotationally fixed component and to drivingly couple the other of the carrier arm and the ring gear to the sleeve ring depending on the direction of rotation of the motor. Different gear ratios are selected by reversing the direction of rotation of the motor whilst the sleeve ring is always driven in same direction. The speed change apparatus may be part of a hub of an electric vehicle in which the sleeve ring is a hub shell and the apparatus is mounted about an axle.

Abstract: A speed changing apparatus includes a planet gear set having a sun gear, planet pinions, a planet pinion carrier and a ring gear mounted inside a rotary sleeve. The sun gear is driven by a D.C. motor to rotate in either of two opposed rotary directions. Clutch arrangements are operative to lock one of either the carrier arm or the ring gear to a rotationally fixed component and to drivingly couple the other of the carrier arm and the ring gear to the sleeve ring depending on the direction of rotation of the motor. Different gear ratios are selected by reversing the direction of rotation of the motor whilst the sleeve ring is always driven in same direction. The speed change apparatus may be part of a hub of an electric vehicle in which the sleeve ring is a hub shell and the apparatus is mounted about an axle.