A keyboard includes a mechanical structure and a key attached to the mechanical structure. A light emitting diode configured to emit light into a light guide panel. A reflector may be attached to the light guide panel and be configured to reflect light from the light guide panel through an opening in the mechanical structure to illuminate a periphery of the key.

A circuit structure includes a light-transmissive insulation layer, a patterned conductive layer and an electronic component. The patterned conductive layer is disposed on the light-transmissive insulation layer. The electronic component is disposed on the patterned conductive layer and electrically connected to the patterned conductive layer.

A backlight module includes a flexible circuit board and a light guide plate. A first light source assembly, a second light source assembly, and a positioning member are disposed on the flexible circuit board. The light guide plate is disposed over the flexible circuit board and includes a first single key light guide area, a second single key light guide area, and a connection area. The first single key light guide area has a first through hole accommodating the first light source assembly. The second single key light guide area has a second through hole accommodating the second light source assembly. The connection area is located between the first and second single key light guide areas and has an accommodating hole. The flexible circuit board is overlapped with the light guide plate with the positioning member being accommodated in the accommodating hole.

A control device includes a button assembly having one or more buttons and a button carrier that includes a plurality of resilient, independently deflectable spring arms. The control device may be configured as a wall-mounted keypad to control a load control device, or as a thermostat to control a temperature regulation appliance. The button carrier may be configured to prevent interference between the buttons during operation of the control device. The button assembly may be captured between a faceplate of the control device and a housing that is attached to a rear side of the faceplate. The control device may include one or more button retainers that are attached to the buttons and that are configured to align respective outer surfaces of the buttons relative to each other, and relative to the faceplate of the control device, when the buttons are in respective rest positions.

A light guiding device is applied to an indication apparatus with a lighting function. The light guiding device includes a light guiding component and a piercing hole structure. The light guiding component has an incident surface and an emergent surface. The piercing hole structure is disposed between the incident surface and the emergent surface. An inner wall of the piercing hole structure includes at least one arc surface portion and at least one plane surface portion. Alight beam from the incident surface can be turned to a first angle via the arc surface portion, and the light beam can be turned to a second angle via the plane surface portion, so as to evenly project the light beam onto the emergent surface. A dimension of the emergent surface is greater than a dimension of the incident surface, and the first angle is greater than the second angle.

A backlight module adapted to an illuminated keyboard is provided. The backlight module includes a light source assembly, a light guide film, and a reflective sheet. The light guide film has a top surface, a bottom surface, a through hole and a light-exit pattern. The light source assembly includes a light-emitting component configured to emit light toward the through hole. A size of the through hole is smaller than a size of the light-emitting component. The light-exit pattern is on the bottom surface and encloses the through hole. The reflective sheet is located above the through hole. A size of the reflective sheet is larger than or equal to the size of the through hole. A distance from the through hole to an outer edge of the light-exit pattern is greater than a distance from to the through hole to an outer edge of the reflective sheet.

An illuminated keyswitch structure is provided. A base plate includes plural openings and plural rib portions separating the openings. A drive circuit board is disposed under the base plate. A spacer having a through hole is disposed underneath the base plate and above the drive circuit board. A light-emitting part with low illuminance is disposed on the drive circuit board and in the through hole, and the light-emitting part vertically corresponding to one of the openings of the base plate. A light-permeable covering structure includes a first covering layer and a second covering layer. The second covering layer vertically corresponds to the light-emitting part and said corresponding opening of the base plate. The second covering layer blocks at least partial light of the light-emitting part toward said corresponding opening to reduce illuminating intensity provided there through.

A backlight module applicable to a key module is provided, the key module includes a plurality of key units and a baseplate, and the plurality of key units are disposed on the baseplate. The backlight module includes a lower substrate, a plurality of periphery light sources disposed along the peripheral of the baseplate, and a shielding structure. The lower substrate is disposed below the baseplate, and there is an outer edge gap between an outer edge of the baseplate and the lower substrate. The periphery light sources are disposed between the baseplate and the lower substrate. The shielding structure is disposed outside those periphery light sources distributed, to prevent light provided by the plurality of light sources from being emitted out of the outer edge gap.

A backlit keyboard includes key switches and a backlight module. The backlight module includes a light guide plate, a reflecting surface, and at least one light-emitting device. The light guide plate is provided with light-guiding dots disposed on a bottom surface thereof. A light-shielding layer disposed on the light guide plate has a light-shielding portion and a light-transmitting portion corresponding to at least one of the key switches. The reflecting surface faces the bottom surface of the light guide plate, and a pattern at least partially overlaps the light-shielding portion. A first light-emitting device and a second light-emitting device are disposed in an opening of the light guide plate, and the first light-emitting device and the second light-emitting device face respective sidewalls of the opening. The first light-emitting device is located underneath the light-shielding portion.

A method and apparatus for ranging finding of signal transmitting devices is provided. The method of signal reception is digitally based only and does not require receivers that are analog measurement devices. Ranging can be achieved using a single pulse emitting device operating in range spaced relation with a minimum of a single signal transmitter and a single digital receiver and processing circuitry. In general a plurality of transmitting pulsed emitters may be ranged and positioned virtually simultaneously in 3-dimensions (XYZ coordinates) using a configuration of a plurality of digital receivers arranged in any fixed 3-dimensional configuration. Applications may involve at least one single transmitter to receiver design to determine range, or at least one transmitted reflecting signal off from an object to determine range.