LED lamp having light guiding heat sink

An LED lamp structure includes a reflection cup, a metal heat sink for receiving a plurality of LEDs, and a heat conducting base. The heat conducting base has a slot for receiving the metal heat sink. The metal heat sink includes guiding planes for redirecting the output of an LED so as to change the angle of projected light. The metal heat sink is made of a good heat conductor with high thermal capacity so that heat produced by the LED is absorbed quickly and conducted to the heat conducting base. The reflection cup is flexed to an outer edge of the metal heat sink to provide a flat lighting characteristic.

FIELD OF THE PRESENT INVENTION

The present invention relates to encapsulation, and particular to an LED lamp structure having a metal heat sink being arranged by guiding planes for receiving LEDs so as to change the angle of light and increase optical efficiency. The metal heat sink is a good heat conductor with high thermal capacity so that heat on LED chips is absorbed quickly and being conducted to a heat conducting base through a large surface thereof. Heat generated from the LED chips of the metal heat sink is dissipated quickly so that temperatures of the LED chips are substantially lowered;

DESCRIPTION OF THE PRIOR ART

Light emitting diode (LED) has advantages of power saving, small size, capability of emitting light in different colors, and environment-friendly. It is well applied on cell phones, automobiles, back light for medium and small size panels, traffic lights, and further into illumination field. Recently, LED illumination for outdoors is extensively developed so as to take the place of traditional illumination. However, high power LED has a thermal problem. The higher the power of the LED is, more heat is generated, and the LED keeps higher temperature. While the temperature of an LED chip goes higher, the light output efficiency is lowered and the life time of the LED chip is shortened. Thus, a good lamp body structure with well heat dissipation ability, suitable for a flat lighting characteristic of a LED, capable of changing angle of light, raising optical efficiency is an important subject to develop.

On the other hand, the prior illuminating device is also improved about heat dissipation such as the Taiwan patent no. M289519 about an ultra high efficiency package structure. According to the patent, a single or multiple LED chips are installed on a carrying surface of a metal heat sink of well thermal conductibility, and the metal heat sink is sat on a heat conducting base through a heat conducting and electrical insulating layer. Three components are combined so as to dissipate heat on the LED chips quickly. However, an LED array arrangement will have the lights been blocked and absorbed by the LED chips so that the lighting efficiency will be lowered. While the quantity of the LED chips or the power of the LED chip is higher, temperature of certain part of LED chips goes too high. Accordingly, a good and simple structure to solve the thermal problem is provided in the following. With guiding planes added to the metal heat sink, a structure of the guiding planes enlarges the heat dissipation area so that heat on the LED chips are dissipated and temperature of the metal heat sink will not become too high. In the same time, the guiding planes can change projecting angle of lights so as to raise optical efficiency. With a surface area added by the metal heat sink, heat on the LED chips of the metal heat sink is absorbed quickly and being conducted to the heat conducting base so that heat on the LED chips of the metal heat sink is dissipated quickly and temperatures of the LED chips are substantially lowered. The comprehensive heat dissipating effect can extend a lifetime of the LED and it is also the technical point that the inventor of the present invention want to solve.

SUMMARY OF THE PRESENT INVENTION

To achieve above objects, an LED lamp structure according to the present invention includes a reflection cup, a metal heat sink, and a heat conducting base. The heat conducting base has a recess for receiving the metal heat sink. The metal heat sink is formed with guiding planes which are suitable for receiving LEDs so as to change the angle of lights and increase optical efficiency. The metal heat sink is a good heat conductor with high thermal capacity so that heat on a LED chip is absorbed quickly and being conducted to the heat conducting base through a larger surface thereof. Heat generated from the LED chips of the metal heat sink is dissipated quickly so that temperatures of the LED chips are substantially lowered. The reflection cup suitable for the flat LED is fixed to an outer edge of the metal heat sink. The reflection cup has a reflecting curved surface on an inner wall thereof. By the different reflecting curvatures of the reflection cup, different light projection distributions are formed.

DETAILED DESCRIPTION OF THE INVENTION

Referring toFIGS. 1 and 2, an LED lamp structure according to the present invention includes a reflection cup1, a metal heat sink2, and a heat conducting base3. The heat conducting base3has a recess31and through holes32on a bottom side of the recess31. The metal heat sink2inserts into the recess3to be fixed therein. A plurality of bolts are screwed into the through holes32for retaining a lighting device. The slot31further has through holes30formed inside thereof. The metal heat sink2is formed with a plurality of guiding planes21which are suitable for a flat lighting characteristic of an LED so as to change the angle of light and increase optical efficiency. The metal heat sink2is a good heat conductor and has higher thermal capacity so that heat generated from LED chips is absorbed quickly and being conducted to the heat conducting base3through a large surface thereof. Heat on the LED chips of the metal heat sink2is dissipated quickly so that temperatures of the LED chips are substantially lowered. The reflection cup1suitable for the flat lighting characteristic of LED is fixed to an outer edge of the metal heat sink2. The reflection cup1is a hollow body with two openings and a reflecting curved surface11is formed on an inner wall. A concave edge12is formed to an opening of the reflection cup1and a joint13is formed to another opening of the reflecting cup1for connecting with an outer edge of the metal heat sink2. By the different reflecting curvatures of the reflection cup1, different light projecting distributions are formed.

With reference toFIGS. 3 and 5, through holes20are formed in to the metal heat sink2for arranging the pins of the LED chips10. A plurality of guiding planes21are formed on a surface of the metal heat sink2by stamping beside the through holes20. The plurality of guiding planes21having large inclined planes on a right side of the through holes20are formed on a right half surface of the metal heat sink2, while guiding planes21with inclined plane on a left side of the through holes20are formed on a left surface of the metal heat sink2. Lights emitted from the LED chips10will be guided to the right side and left side by the guiding planes21and through the reflecting curved surface11of the reflection cup1, lights will be projected uniformly on both right and left sides.

Referring toFIG. 4, another preferable embodiment of the present invention is illustrated. To have a higher efficiency of heat dissipation, a heat dissipating area of the metal heat sink2′ is enlarged. Wing sheets22are added for enlarging the contact area between the metal heat sink2′ and the heat conducting base3′ having a recess31′ so that heat on high power LED chips are absorbed and are conducted to the heat conducting base3′ more quickly. Heat generated from the LED chips of the metal heat sink2′ is dissipated quickly so that temperatures of the LED chips are substantially lowered.