摘要:
A method and apparatus for a sensor network having a plurality of reference nodes and a sensor node that enables the sensor node to compute a relative position through transmission range control and position mapping. In transmission range control, each reference node sends location information signals to the sensor node while varying transmission power. In position mapping, the sensor node forms a grid of vertical and horizontal lines corresponding to a square area defined by the neighboring reference nodes, extracts coordinates of intersections in the grid belonging to a shared region between areas covered by location information signals of various transmit power levels from the neighboring reference nodes, and sets the position of the sensor node to the middle points of the extracted coordinates. Each reference node sends a location information signal when a random backoff time expires after reception of a location information request signal.
摘要:
For a sensor network having reference nodes and sensor nodes, A method and apparatus using a distance determining algorithm for a sensor network having reference nodes and sensor nodes. A distance determining algorithm is executed to determine an adequate distance between reference nodes within a preset error range, and a position location table is created. A sensor node sends a location information request to reference nodes, receives the position location table and location information from the reference nodes, and computes the coordinates of its position. Alternatively, without requesting transmission of the position location table, the sensor node may receive calculated coordinates of its position directly from a reference node.
摘要:
A method and apparatus for a sensor network having a plurality of reference nodes and a sensor node that enables the sensor node to compute a relative position through transmission range control and position mapping. In transmission range control, each reference node sends location information signals to the sensor node while varying transmission power. In position mapping, the sensor node forms a grid of vertical and horizontal lines corresponding to a square area defined by the neighboring reference nodes, extracts coordinates of intersections in the grid belonging to a shared region between areas covered by location information signals of various transmit power levels from the neighboring reference nodes, and sets the position of the sensor node to the middle points of the extracted coordinates. Each reference node sends a location information signal when a random backoff time expires after reception of a location information request signal.
摘要:
For a sensor network having reference nodes and sensor nodes, A method and apparatus using a distance determining algorithm for a sensor network having reference nodes and sensor nodes. A distance determining algorithm is executed to determine an adequate distance between reference nodes within a preset error range, and a position location table is created. A sensor node sends a location information request to reference nodes, receives the position location table and location information from the reference nodes, and computes the coordinates of its position. Alternatively, without requesting transmission of the position location table, the sensor node may receive calculated coordinates of its position directly from a reference node.
摘要:
Disclosed herein is a Light Emitting Diode (LED) light source lens for emitting light in a lateral direction. The LED source lens includes an upper part, an upper part and a central part. The upper part includes an upper part reflecting surface bent symmetrically with respect to the central axis of the lens, and an upper part refracting surface extended from the end of the upper part reflecting surface parallel with the central axis. The central part includes a side surface extended from the lower end of the upper part refracting surface and bend inwards, and refracts or reflects light through the side surface. The lower part accommodates the LED light source, and includes an arch-shaped lower part refracting surface extended outwards from the lower end of the side surface of the central part. The light radiated from the LED light source is emitted perpendicular to the central axis.
摘要:
A lens includes a convex surface formed in an outer surface thereof facing away from a light source to uniformly distribute light emitted from the light source; a concave surface concaved inward from an inner region of the convex surface, around an optical axis; and a convex portion convexed outward from a central region of the concave surface, which the optical axis intersects, in order to enhance quantity of light around the optical axis. The lens refracts light beams falling onto the respective areas thereof at different angles, thereby producing a uniform light distribution within a specific lighting range, but does not create a dark area around an optical axis.
摘要:
An LED package frame includes an LED chip and a heat conductive member made of high heat conductivity material. The heat conductive member has a receiving part at a lateral portion, and is mounted with the LED chip. A lead-coating assembly configured to be inserted into the receiving part of the heat conductive member, including a lead is inserted at one end into the receiving part of the heat conductive member, and electrically connected to the LED chip. An electrically insulating layer is placed in tight contact between the lead and the receiving part of the heat conductive member isolates the lead from the receiving part. With the lead inserted into the heat conductive member, it is possible to reduce size while maintaining high heat conductivity and stability.
摘要:
A direct-illumination backlight apparatus using LEDs includes a flat reflective plate, an LED light source, a transparent plate, a scattering pattern, and a light guide. The light guide serves to introduce a partial light from an LED light source at such an angle that the partial light is trapped inside the transparent plate, and the scattering pattern serves to scatter the trapped light beam at a position directly above the LED light source so that the scattered light beam escapes out of the transparent plate toward an LCD panel.
摘要:
The invention relates to a direct backing type LED backlight apparatus which supplies a white light source by mixing monochromatic LEDs to a display device. The backlight apparatus includes a first LED row composed of red LEDs disposed adjacent to opposed peripheries of a substrate with green, blue and red LEDs alternately disposed between the red LEDs at the peripheries. The backlight apparatus also includes a second LED row having a similar arrangement of LEDs with blue LEDs disposed adjacent to the opposed peripheries. The backlight apparatus regulates the amount of radiation from the red and blue LEDs to be smaller than the amount of radiation from the rest of the LEDs. This allows elimination of color deflection at the peripheries of a light guide panel.
摘要:
In a backlight apparatus for an LCD, a plurality of bar-shaped first LED light sources are arranged on the reflective plate to laterally emit light. A plurality of light shades are arranged above the first light sources. A transparent plate is placed above the light shades. Scattering patterns are formed in the bottom of the transparent plate in positions corresponding to the light shades. A bar-shaped second LED light source is arranged at a side of the transparent plate to emit light into the transparent plate. The light source arranged at the side of the transparent plate prevents the formation of dark areas as a problem in the prior art, thereby enhancing the entire uniformity of light. Then, the backlight apparatus can be maintained thin even when applied to a large-sized LCD.