Abstract: A key includes a light-permeable body, a light-shading layer and a first dye layer. The light-shading layer is formed on the surface of the light-permeable body and has a first light-permeable area and a second light-permeable area. The first dye layer is formed on the first light-permeable area.

Abstract: A negative voltage detector includes a first n-channel transistor having a coupled gate node and drain node, a second n-channel transistor having a gate coupled to the gate of the first n-channel transistor, a first current source coupled to a drain of the first n-channel transistor, a second current source coupled to a drain of the second n-channel transistor, an output terminal coupled to the drain of the second n-channel transistor, and an input terminal coupled to a source of the first n-channel transistor. The gate voltage of the first n-channel transistor, i.e., the gate voltage of the second n-channel transistor, depends on its source voltage (the voltage of the input terminal), and the switching operation of the second n-channel transistor can be performed by controlling the voltage of the input terminal to change the output voltage of the output terminal.

Abstract: A coffee maker includes a boiler, a milk whipper, and a selector. The boiler supplies steam to the milk whipper. The milk whipper is inserted to a hollow cap connecting through the milk whipper. The milk whipper contains a suction tube to suck the milk at the bottom of a milk cup into the upper section in the cap to be fast beaten into cream. The selector includes a lid, an elastic member, and a base. The lid is connected through the boiler. The elastic member is fixed to the base. The lid is pivoted to the base and holds against the elastic member in its normal status. Hot water is supplied by turning a hot water supply line of the lid to align with a water outlet of the base. Steam is supplied by turning a steam supply line of the lid to align with a steam outlet of the base.

Abstract: A key includes a light-permeable body, a light-shading layer and a first dye layer. The light-shading layer is formed on the surface of the light-permeable body and has a first light-permeable area and a second light-permeable area. The first dye layer is formed on the first light-permeable area.

Abstract: A portable device and a rotating and positioning mechanism thereof. The rotating and positioning mechanism includes a first body, a second body, and a sliding member. The second body has a rotational shaft, rotatably disposed along the rotational shaft with respect to the first body. The sliding member is slidably disposed on the rotational shaft and disposed in the first body. When the second body rotates to a predetermined angle, the sliding member engages the second body, thereby securing the second body to the first body.

Abstract: A paper-flattening device includes a stationary seat unit to be mounted adjacent to a paper-supporting tray of a feeding apparatus, a spindle member disposed rotatably in the stationary seat unit, an arm member fixed on the spindle member for co-rotation therewith, and a cam unit disposed between and coupling the seat unit and the spindle member in such a manner that rotation of the spindle member in first and second directions results in movement of the spindle member together with the arm member to upper and lower positions. When at the lower position, the arm member slidably contact the paper in the tray to prevent curling and folding of the paper.