Abstract: A system for lighting an interior of a building according to one example embodiment includes a curb positioned on an exterior of the building for receiving natural light. A light duct is positioned within the curb having a reflective inner surface for transferring the natural light. A light fixture is connected to an outlet of the light duct such that both natural light and artificial light are emitted from the light fixture to the building interior. A photo sensor is positioned in the building interior to sense an illumination level therein. A controller in communication with the photo sensor and the light fixture is programmed to adjust the amount of light emitted by a dimmable light source in the light fixture in response to fluctuation in the illumination level sensed in the building interior in order to maintain a desired illumination level.

Abstract: Provided is a charged particle beam apparatus, which can emit a stable electron beam, having high brightness and a narrow energy width. The charged particle beam apparatus comprises a field emission electron source, electrodes for applying an electric field to the field emission electron source, and a vacuum exhaust unit for keeping the pressure around the field emission electron source at 1×10?8 Pa or less. The apparatus is so constituted as to use such one of the electron beams emitted as has an electron-beam-center radiation angle of 1×10?2sr or less, and to use the electric current thereof, the second order differentiation of which is negative or zero with respect to the time, and which reduces at a rate of 10% or less per hour. The charged particle beam apparatus further comprises a heating unit for the field emission electron source, and a detection unit for the electric current of the electron beam.

Abstract: The present invention provides an electric axial-flow fan having turbine type waterproof enclosure, which is rainproof and installed at the top portion of sealed heat dissipation housing of a high power lamp, so when the electric axial-flow fan is operated, the airflow passes through the top portion of lamp housing, which is relatively hotter, of the sealed heat dissipation housing and is concentrated towards the center, then leaded to upwardly enter an axial airflow inlet port formed at the bottom of the turbine type waterproof enclosure, thereby being exhausted to the surroundings through radially-arranged exhaust blades, thus when the present invention being applied in a high power lamp, an air cooling effect by external airflow can be provided to the top portion, which is relatively hotter, of the lamp housing, without influencing the waterproof sealing effect.

Abstract: A light source system capable of dissipating heat includes a AC power supply for outputting a first power, a switch device for adjusting an output ratio of the first power according to a light setting, a light emitting device for generating a light source, and a control device for generating an active signal sequence, an heat-dissipation signal sequence and a burst signal according to lighting features of the light emitting device, and combining the active signal sequence and the heat-dissipation signal sequence, to generate a driving signal sequence, for timely outputting the driving signal sequence according to the burst signal, so as to generate the control signal.

Abstract: The present invention is directed to an illumination system adaptable to a cooling appliance. The illumination system includes a lighting module, a mode switch and a controller. Specifically, the lighting module includes at least one lighting device; the mode switch is used to determine a power mode for the lighting module; and the controller provides corresponding power to the lighting device according to the power mode. In one embodiment, the illumination system further includes a heating module having a heater for providing heat to the controller. In another embodiment, the lighting device is disposed near the controller.

Abstract: The present invention relates to the development of a method and system for manufacturing and deploying light emitting diode (“LED”) technology in a highly efficient manner. Devices of the invention include a printed circuit board with a heat sink and at least one LED insertion site and optionally a wireless communication device to control operation of the LED.

Abstract: A light source device having a large cooling action on the base member of a discharge lamp. A connector on the sides of the power supply and the air blower and the base-side connector of a discharge lamp are connected to each other through a connection cable having a power cable in which an air blow pipe is contained. An electric power is supplied from the power supply to a base part through the power cable of the connection cable, the base-side connector and a flow passage bending member. The cool air from the air blower is supplied to the groove part of the base part through the air blow pipe of the connection cable, the base-side connector and an air blow passage in the flow passage-bending member.

Abstract: A light-emitting diode (LED) bulb has an LED within a shell. The LED bulb includes a driver circuit for providing current to the LED. The drive circuit has a thermal protection circuit, which includes a first positive thermal coefficient thermistor with a first switching temperature connected in series with a second positive thermal coefficient thermistor with a second switching temperature. The driver circuit includes a switch-mode power supply (SMPS) controller with an input pin and an output pin. The thermistors are connected to the input pin. When either thermistor temperature is above the respective switching temperatures, the thermal protection circuit causes the SMPS controller to produce a signal with a second duty cycle on the output pin. When both thermistor temperatures are below the respective switching temperatures, the thermal protection circuit causes the SMPS controller to produce a signal with a first duty cycle on the output pin.

Abstract: A lamp includes a lighting module providing illumination, a control unit, and a detecting unit. The control unit is connected or not connected to the lighting module. The detecting unit is coupled to the control unit. The detecting unit detects operational statuses of the lighting module and sends a detection result to the control unit. The control unit controls the lighting module or an alarm unit to enter an alarm mode based on the detection result. A user can immediately know the operational statuses by the alarm unit and take necessary actions to assure normal operation of the lamp.

Abstract: A circuit arrangement is provided for operating a fluorescent lamp with a first and a second filament, the circuit arrangement including a heater for the first and the second filament, wherein the circuit arrangement furthermore includes: an apparatus for storing at least one threshold value for at least one operational parameter of the fluorescent lamp; an apparatus for determining the value of the at least one operational parameter; and a control apparatus, which is configured to activate the heater for the first and the second filament for a predeterminable period of time in the event of the at least one threshold value for the at least one operational parameter being exceeded by the determined value of the at least one operational parameter.

Abstract: A magnetron includes: an anode tube; and cooling fins placed on a periphery of the anode tube, and arranged along a central axis of the anode tube. Each of the cooling fins includes at least two sets of fins formed by cutting a part of the cooling fin, and performing different bending works on the cut portions, respectively, so as to form a region where the cooling fins are dense and a region where the cooling fins are sparse, when viewed in a flowing direction of a cooling medium which cools the anode tube through the cooling fins. The at least two sets of fins are bent at bending angles such that intervals of the cooling fins in the region where the cooling fins are dense are ½ or less of placement intervals of the cooling fins.

Abstract: Representative embodiments of the disclosure provide a system, apparatus, and method of controlling an intensity and spectrum of light emitted from a solid state lighting system. The solid state lighting system has a first emitted spectrum at full intensity and at a selected temperature, with a first electrical biasing for the solid state lighting system producing a first wavelength shift, and a second electrical biasing for the solid state lighting system producing a second, opposing wavelength shift. Representative embodiments provide for receiving information designating a selected intensity level or a selected temperature and providing a combined first electrical biasing and second electrical biasing to the solid state lighting system to generate emitted light having the selected intensity level and having a second emitted spectrum within a predetermined variance of the first emitted spectrum over a predetermined range of temperatures.

Abstract: A solid-state lighting device (500) includes a plurality of light-emitting elements (510, 525, 530) configured for generating light that are thermally coupled to a heat spreading chassis configured for coupling to one or more heat sinks (520). The lighting device further includes a mixing chamber which is optically coupled to the plurality of light-emitting elements and configured to mix the light emitted by the plurality of light-emitting elements. A control system is operatively coupled to the plurality of light-emitting elements, and configured to control operation of the plurality of light-emitting elements.

Abstract: An illumination device is provided for controlling a color temperature of light irradiated from a light source having a plurality of light-emitting elements of different light colors. A control setting module provides a control signal associated with a desired color temperature for the irradiated light. A light quantity determination circuit determines light quantities for each of the light-emitting elements based on a relationship between the control signal from the control setting module and an inverse color temperature. A plurality of driver circuits provide driver signals to the light-emitting elements corresponding to the determined light quantities. In this manner the color temperature for light irradiated from the light source coincides with the desired color temperature.

Abstract: A lighting system is described. The lighting system includes a lamp and a first container including a first phase change material thermally connected to the lamp. Heat generated by the lamp during operation is conducted to the first phase change material. The system also includes a second container including a second phase change material thermally connected to the lamp. Heat generated by the lamp during operation is also conducted to the second phase change material, and the second phase change material has a transition point temperature lower than the transition point temperature of the first phase change material of the first container to account for a temperature drop between the second container and the first container. The lighting system also includes a temperature sensor for reducing lamp power if the lamp becomes too hot, and a mounting bracket which may also conduct heat away from the lamp.

Abstract: LED lighting systems and methods of manufacture, which include one or more of the following: (1) a solid state active heat sink for cooling one or more LED chips; (2) a front end power supply providing high voltage to the active heat sink component; (3) a front end power supply that provides a relatively low voltage load to a plurality of LED chips; (4) a front end hybrid power supply with both a high and low voltage output, wherein the high voltage is at least 2 kV higher than the low voltage output; (5) an over-mold encapsulating the front end components, wherein the over-mold is provided by a reaction injection molding process; (6) a digital micro-minor device (DMD) for providing pixilated light, color mixing, and intensity control; and (7) an optic having quantum dots (QDs), wherein the light output of the DMD activates for the QDs.

Abstract: There is provided a lamp capable of informing a user that the LED lamp is at the end of its productive life and urging the user to replace the lamp reliably with a simple configuration. The lamp includes: a light emitting diode (1) as a light source; and a driving circuit (3) that turns on the light emitting diode (1) by an alternating-current or direct-current power source. The lamp further includes a life detecting element (2) that turns off the light emitting diode (1) following the occurrence of insulation deterioration in a resin material when the light emitting diode (1) has been operated for a predetermined time.

Abstract: Color temperature of a lighting apparatus that includes a first LED that emits a white light with a first color temperature and a second LED that emits a white light with a second color temperature is managed. The two LEDs are connected in parallel anode to cathode so that current flowing in one direction turns on the first LED and current flowing in the opposite direction turns on the second LED. A controller manages a duty cycle of an alternating current flowing through the two LEDs to control the color temperature and/or the brightness of the lighting apparatus.

Abstract: A lighting control system determines an optimal way to operate one or more lamps to achieve a desired light output and/or to control one or more parameters. The lighting control system includes a detection circuit and a control circuit. The control circuit performs a wide-scope scan and a narrow-scope scan to find the best way to operate the lamps. The wide-scope scan includes driving the lamp(s) using multiple output settings, evaluating the light output at each setting, and determining which setting produced the best results. The narrow-scope scan includes making small adjustments to the settings to better refine the light output. The detection circuit includes one or more sensors for providing measurements of the light output by the lamp(s) or of a controller parameter, such as power consumption, for each setting evaluated by the control circuit.

Abstract: In a lighting device (100) comprising an AC light source (14) and a cooling arrangement (52, 62) and a coil (11) for producing a magnetic field for driving the arrangement (52, 62), the coil (11) is serially coupled to the AC light source (14) for making the lighting device (100) more compact. The arrangement (52, 62) comprises a moveable part for displacing a quantity of air or another gas or a fluid. Preferably, the lighting device (100) comprises a further coil (21) for producing a further magnetic field for further driving the arrangement (52, 62), and a phase-shift is introduced between currents flowing through the coil (11) and the further coil (21). The AC light source (14) comprises a combination of a rectifier and a light emitting diode and/or comprises a combination of at least two light emitting diodes combined in an anti-parallel manner.

Abstract: A pulsed diode light source driver includes a variable output power supply, an output capacitor, a switchable linear current driver, a temperature sensor, a conditioning circuit, and a voltage monitor. The temperature sensor monitors the temperature of the capacitor while the voltage monitor circuit monitors the output voltage level. The conditioning circuit and the voltage monitor cooperatively control the output voltage of the variable output power supply, so that temperature-related changes in the characteristics of the capacitor are compensated for, and a constant current is maintained through the diode load over a desired range of temperature. The driver is suitable for laser diodes and light emitting diodes.

Abstract: A luminaire has a light source in the form of a quartz crucible, having a plasma void. A power supply has a magnetron for providing microwaves for generating a plasma in the void. An air wave guide is connected below the magnetron and a connector is connected below the wave guide. The plasma crucible is fitted to the bottom of the connector and is enclosed by a Faraday cage. Arranged with the crucible at its focal point is a reflector. It has a central aperture through which the connector extends. A lower, hemispherical shell of a casing for the power supply supports the reflector at a similar aperture, with the interposition of one or more focus adjusting spacers.

Abstract: The present disclosure discloses a dimming method of a lighting apparatus using a PN junction light-emitting element, the method including: supplying AC controlled by a dimmer; causing a first group, which has one PN junction light-emitting element positioned within a first boundary and one PN junction light-emitting element positioned within a second boundary, to emit light at a first voltage by the supplied AC when a first switch is in the ON state; and causing a second group, which has another PN junction light-emitting element positioned within the first boundary and another PN junction light-emitting element positioned within the second boundary and which is connected in series to the first group, to emit light at a second voltage higher than the first voltage by the supplied current when the first switch positioned between the first group and the second group is in the OFF state.

Abstract: An LED lamp including a glass lampshell and a stem assembly with one end inserted into the glass lampshell. The stem assembly comprises a glass trumpet tube with one end sealed within the glass lampshell to form a cavity within the glass lampshell and within the cavity a supporting component connected to the glass trumpet tube and supporting an LED emitter. The stem assembly further comprises a wire encompassed within the glass trumpet tube. The wire has one end extending outside of the cavity and the other end electrically connected to the LED emitter.

Abstract: A modular solid-state lamp has a plurality of replaceable and rearrangeable modules. The modular lamp uses active cooling and passive cooling for thermal management. One cooling system for the modular lamp includes at least one active cooling device and a graphite heat sink in thermal contact with the at least one active cooling device to further enhance the efficiency of the cooling system. The modular solid-state lamp includes at least two modules, a power supply module and a light source module. The power supply module includes a power supply and LED driver that are able to power one or more light source modules. The power supply module further includes sensors that further improve the energy-efficiency of the lamp.

Abstract: An LED lamp with replaceable light unit according to the invention includes a heat dissipation housing, a metal connector, a driver circuit board, a light unit slice, a pad and a shade. The heat dissipation housing has an opening at one end and a joint portion at another end. The metal connector is disposed to the joint portion of the heat dissipation housing. The driver circuit board disposed inside the heat dissipation housing to electrically connect with metal connector. The light unit slice and the pad are disposed inside the opening, and the light unit slice is electrically connected with the driver circuit board. The shade is disposed inside the opening. The LED lamp with replaceable light unit can be realized by the assembly of the above elements according to the different preferred embodiment of the present invention.

Abstract: The present invention provides a Scalable Heat Dissipating Microelectronic Integration Platform (SHDMIP) LED Package having excellent heat dissipation and protection to LED, thus extending the lifespan of the LED. The SHDMIP LED package comprises a dual lead frame assembly comprising bottom and top lead frame, protection and driver circuits conductively attached to the bottom lead frame and a LED conductively attached to the top lead frame. The bottom lead frame comprises heat sink pad for heat dissipation purpose. Plurality of SHDMIP LED packages of the present invention can be configured in a matrix or row, forming a SHDMIP LED array for various lighting solutions. A method to manufacture the SHDMIP LED array of the present invention is provided herein.

Abstract: A color temperature tunable white light source comprises: first and second LED arrangements operable to emit light of first and second wavelength range respectively that are configured such that their combined light output, which comprises light generated by the source, appears white in color. One or both LED arrangements comprises a phosphor provided remote to an associated LED operable to generate excitation radiation and to irradiate the phosphor such that it emits light of a different wavelength range, wherein the light emitted by the LED arrangement comprises the combined light from the LED and phosphor. The color temperature of output white light is tunable by controlling the relative light outputs of the LED arrangements by for example controlling the relative magnitude of the drive currents of the LEDs or a duty cycle of a pulse width modulated drive current.

Abstract: The LED headlamps for vehicles provide a modular efficient light source for vehicle headlamps. The invention addresses the LED negative temperature coefficient in efficient heat removal system. Beam direction and pattern is controlled by its composite lens beam shaping mechanism. The beam targeting using the LED source is done through beam shaping via lens surface shaping, lens curvature contouring and composite lens component offsetting from the LED source or outgoing beam axis to direct the light beam.

Abstract: An LED drive circuit that drives an LED is provided with: a rectifying circuit that converts an alternating voltage into a pulsating current; a constant current circuit; and an over-temperature protection portion that limits an output of the constant current circuit, wherein the LED and the constant current circuit are connected in series on an output side of the rectifying circuit.

Abstract: An optical transmission module includes a light source element for emitting a predetermined light signal transmitted through an optical fiber, the light source element having lower characteristics in a low-temperature state than those in a high-temperature state, a driver circuit for driving the light source element, and a heat transfer member connected to each of the light source element and the driver circuit to transfer heat between the light source element and the driver circuit. The optical transmission module with such configuration can stably operate in a wide temperature range while achieving power saving and cost reduction.

Abstract: A light source comprising a light emitter; a heat sink coupled to the light emitter; and a temperature sensor substantially adjacent to the light emitter. A first thermal time constant associated with the temperature sensor is less than a second thermal time constant associated with a radiation surface of the heat sink.

Abstract: A microwave-excited ultraviolet lamp system includes a microwave chamber cooled with air drawn through the chamber by a negative pressure source. A filter provided at an inlet of the lamp system prevents particulate material from entering the microwave chamber.

Abstract: A metal halide lamp capable of delaying the rate of deformation in an electrostrictive phenomenon caused by the discharge of a ferroelectric ceramic capacitor when dielectric breakdown is initiated between the electrodes of an arc tube thereby preventing breakage accident, wherein a starting circuit, housed in parallel connection together with an arc tube in an outer tube of a metal halide lamp has in serial connection, a ferroelectric ceramic capacitor that is charged and discharged when a voltage at a predetermined coercive voltage or higher is applied thereby outputting a starting pulse at a high voltage from a ballast, a semiconductor switch that turns to a conduction state when a voltage of a predetermined breakover voltage or higher is applied, and a time constant control resistor that delays the discharge time of electric charges discharged from the capacitor when dielectric breakdown is initiated in the arc tube.

Abstract: An LED (Light-Emitting Diode) driving device is electrically connectable with an alternating current (AC) power supply and includes an electronic converter received in the driving device and a first connector, which is formed on an end of the driving device to connect with the AC power supply and in electrical connection with the electronic converter, and a second connector, which is formed on another end of the driving device for connection with an LED lighting module. When the first connector is set in electrical connection with the AC power supply, the above arrangement allows for conversion of electrical current and voltage to those applicable to an LED lighting module within 10 W rating.

Abstract: A method for detecting motion direction of an object (4) comprises the steps of: laser output light (L1) is generated, using a semiconductor laser (2) having a thermal response frequency (fr); the laser is driven with rectangularly modulated DC current (I) having a modulation frequency higher than said thermal response frequency (fr) and preferably higher than twice said thermal response frequency (fr), such as to triangularly modulate the wavelength of the laser output light; the laser output light is directed to the object; a portion of reflected light (L3) is allowed to interfere with light (L0) within the laser; a portion of the laser light is used as measuring beam (5); the frequency spectrum of the measuring beam (5) is analyzed in conjunction with the modulated laser current in order to determine the direction of movement of the object (4).

Abstract: An air-cooling illumination apparatus capable of reducing deteriorations caused by the heat generated by the illumination apparatus includes a fan, a lamp installed on an air passage movable by a rotation of the fan, a connecting portion connected to the lamp and the fan, and a plate portion formed at an air suction end of the fan and arranged with a first interval apart from the fan. The fan includes a rotatable vane portion, and a frame mounted around the periphery of the vane portion. The lamp is installed at the periphery of the frame and includes an air blowing end for blowing air from the fan and a projecting portion for projecting light. A second interval is formed between the lamp and the plate portion.

Abstract: A thermal foldback circuit protects a lamp circuit component from overheating by limiting power to the lamp in response to an over-temperature condition. The amount of limiting is adjusted based at least in part on an input from an external power-reduction source, such as a dimmer.

Abstract: The present invention relates to an electronic ballast for discharge lamps (LA) which have preheatable electrodes (E1, E2). The electronic ballast has a measuring apparatus (M), which is designed to measure, during the preheating process, a variable, which is correlated with the electrode temperature increased by the preheating, of at least one of the electrodes (E1, E2) of a connected discharge lamp (LA), and a control apparatus (C), which is designed to match the electrode temperature, during the preheating process, in response to the measurement by adjusting an operational parameter of the electronic ballast. Furthermore, the electronic ballast is designed to detect cross discharges or a sufficient operating temperature of one of the electrodes (E1, E2) and possibly to ignite the discharge.

Abstract: An LED light emitting device includes a lamp housing, an LED light emitting component thermally attached to the lamp housing, a power source driver for providing electric energy for the LED light emitting component, and a temperature sensor attached to the lamp housing for sensing a surface temperature of an outer surface of the lamp housing. When the value of the surface temperature is smaller than a predetermined temperature value, the temperature sensor outputs a control signal to the power source driver to control the power source driver to supply a larger electric current to the LED light emitting component, and the LED light emitting component generates more heat to the lamp housing to increase the surface temperature thereof.

Abstract: An LED light emitting device includes an LED light emitting component comprising a visible LED die emitting visible light and an infrared LED die emitting infrared light, a power source driver for providing electric energy for the LED light emitting component, and a temperature sensor for sensing a surface temperature of an outer surface of the LED light emitting component. When a value of the surface temperature is smaller than zero degree Celsius, the temperature sensor outputs a control signal to the power source driver to control the power source driver to supply an electric current to the infrared LED die, whereby the infrared LED die radiates infrared light to melt ice on the outer surface of the LED light emitting component.

Abstract: Certain embodiments of the invention may include systems, methods, and apparatus for improving the visibility and identification of satellites using light emitting diodes. According to an example embodiment of the invention, a method is provided for improving the visibility of satellites. The method can include attaching one or more light emitting diodes (LEDs) to a satellite, supplying one or more signals to the one or more LEDs, and producing light emission having a unique identifier from the one or more LEDs based at least in part on the one or more signals.

Abstract: An illuminant device designed to activate a light source selectively in a plurality of lighting modes. The illuminant device includes a plurality of circuit boards having thermal conductivity and a plurality of lighting circuits each of which is operable to activate the light source in a selected one of the lighting modes. The lighting circuits are mounted on the circuit boards so that when the light source is being activated, the circuit boards will be different in temperature thereof from each other due to heat generated in at least one of the lighting circuits which is activating the light source. The illuminant device also includes a connector which couples the lighting boards together to transfer the heat therebetween, thereby enhancing the dissipation of the heat.

Abstract: A lamp having a light emitting diode, a pettier device, a heat sink, a translucent thermally conductive window, and an optical fluid. The pettier device is in thermal communication with the light emitting diode and converts a waste thermal energy discharged by the light emitting diode into an electrical energy. Conductors transfer the electrical energy from the pettier device to a boost circuit which converts a level of a voltage associated with the electrical energy output from the pettier device to a higher, more useful value. The heat sink transfers a second thermal energy from the pettier device. The optical fluid is located between the translucent thermally conductive window and the light emitting diode. The optical fluid has an angle of diffraction having an intermediate value relative to an angle of diffraction associated with the light emitting diode and an angle of diffraction associated with the translucent thermally conductive window.

Abstract: A high brightness LED (102) is precisely controlled. The temperature of the LED (102) is controlled via controlled thermal resistance (300), measurement of the base temperature (302) and careful power monitoring of the LED (102).

Abstract: The invention relates to a lighting armature or light generator, comprising a housing, a light source and drive electronics for driving the light source, wherein the having cooling fins made of a plastic composition having an orientation averaged thermal conductivity of at least 2.0 W/m·K.

Abstract: The present invention is directed to an illumination system adaptable to a cooling appliance. The illumination system includes a lighting module, a mode switch and a controller. Specifically, the lighting module includes at least one lighting device; the mode switch is used to determine a power mode for the lighting module; and the controller provides corresponding power to the lighting device according to the power mode. In one embodiment, the illumination system further includes a heating module having a heater for providing heat to the controller. In another embodiment, the lighting device is disposed near the controller.

Abstract: A display apparatus and a light source module are provided. The display apparatus includes: a display unit; and a light source module providing light so that an image is displayed on the display unit, the light source module including: a light emitting element which emits the light; a base substrate on which the light emitting element; and a cooling unit including: a capillary tube forming part which a capillary tube inside the base substrate and extending between a first area and a second area farther away from the light emitting element than the first area, and coolant which travels between the first area and the second area in the capillary tube according to a change in phase caused by heat from the light emitting element to transfer the heat from the first area to the second area, and which cools the emitted heat.

Abstract: Alight source device includes: a light emission portion; a cooling channel configured to guide air toward the light emission portion; a rotational member disposed within the cooling channel in such a condition as to be rotatable around a predetermined rotation shaft by gravity, and configured to switch the cooling channel to a first channel branched from the cooling channel in the downstream when the light source device is set in a first position, and to a second channel different from the first channel when the light source device is set in a second position, wherein a position of the center of gravity of the rotational member is located at a position shifted from the center between the rotation shaft and an end of the rotational member away from the rotation shaft toward the end.

Abstract: A heat sink including an inner piece and an outer piece is provided. The inner piece has a side surface. The outer piece is disposed around the inner piece and has an inner side surface, wherein the side surface of the inner piece is riveted to the inner side surface of the outer piece to form an interface, and an area ratio of the interface and the side surface of the inner piece is between 0.6 and 0.95. The light emitting diode lamp using the heat sink is also provided.