Abstract: A smoke detecting device includes a main body, a light-emitter, a first light-receiver, and a second light-receiver. The main body includes a smoke detecting chamber formed therein. The light-emitter is located within the smoke detecting chamber. The first light-receiver is located within the smoke detecting chamber. An optical axis of the first light-receiver and an optical axis of the light-emitter cooperatively define a first scattering angle there-between. The second light-receiver is located within the smoke detecting chamber. An optical axis of the second light-receiver and an optical axis of the light-emitter corporately define a second scattering angle there-between. The second light-receiver is closer to the light-emitter than to the first light-receiver. The second scattering angle is smaller than the first scattering angle.

Abstract: A button structure is provided for installing to a casing of an electronic device having a button opening. The button structure is flexible and comprises an engaging portion, a button portion, a first alignment portion, a second alignment portion and a hollow sleeve. The engaging portion is disposed at a fixing end of the button structure. The button structure is connected to the inward side of the casing through the engaging portion. The button portion is disposed at a free end of the button structure for aligning with the button opening of the casing. The button portion has a light guiding portion for neighboring to a light emitting diode. The first alignment portion and the second alignment portion are mounted on a first protrusion portion and a second protrusion portion of the casing respectively. The hollow sleeve is disposed axially movably to the fixing sleeve of the casing.

Abstract: A button structure is provided for installing to a casing of an electronic device having a button opening. The button structure is flexible and comprises an engaging portion, a button portion, a first alignment portion, a second alignment portion and a hollow sleeve. The engaging portion is disposed at a fixing end of the button structure. The button structure is connected to the inward side of the casing through the engaging portion. The button portion is disposed at a free end of the button structure for aligning with the button opening of the casing. The button portion has a light guiding portion for neighboring to a light emitting diode. The first alignment portion and the second alignment portion are mounted on a first protrusion portion and a second protrusion portion of the casing respectively. The hollow sleeve is disposed axially movably to the fixing sleeve of the casing.

Abstract: A smoke detector is adapted to be coupled to a fire monitoring unit, and includes a power consuming unit and a power supply unit. The power consuming unit is adapted to be coupled electrically to the fire monitoring unit so as to draw electric power therefrom. The power supply unit is coupled electrically to the power consuming unit, and is operable so as to supply electric power to the power consuming unit when the electric power from the fire monitoring unit is cut-off.