1. Field of the Invention
The present invention relates to a light emitting diode (LED) lamp, and more particularly to an LED lamp incorporating vapor chambers for improving heat dissipation of the LED lamp.
2. Description of Related Art
An LED lamp is a type of solid-state lighting that utilizes light-emitting diodes (LEDs) as a source of illumination. An LED is a device for transferring electricity to light by using a theory that, if a current is made to flow in a forward direction through a junction comprising two different semiconductors, electrons and cavities are coupled at the junction region to generate a light beam. The LED has an advantage that it is resistant to shock, and has an almost eternal lifetime under a specific condition; thus, the LED lamp is intended to be a cost-effective yet high quality replacement for incandescent and fluorescent lamps.
LED modules for use in an LED lamp require many LEDs, and most of the LEDs are driven at the same time, which results in a quick rise in temperature of the LED modules. Therefore, a heat dissipation device is needed to dissipate heat generated by the LED modules of the LED lamp. A related heat dissipation device attached to the LED modules usually comprises a heat sink having a base and a plurality of fins mounted on the base. The fins are located parallel to each other and each fin is perpendicular to the base. A plurality of channels are defined between the fins of the heat sink and arranged parallel to each other. A cooling airflow passes through the channels defined by the fins of the heat sink, whereby heat of the fins from the base by absorbing the heat generated by the LED modules can be dissipated to atmosphere. Accordingly, the LED lamp can be cooled to some degree.
However, as a power of the LED modules for use in the LED lamp continues to increase, an amount of heat generated by the LED modules becomes more and more huge. Operation of the conventional LED modules has a problem of instability because of insufficient heat dissipating efficiency of the heat dissipation device. Consequently, the light from the LED lamp often flickers, which degrades the quality of the illumination.
Besides, since the LED modules are generally arranged on a flat surface of a heat dissipation device, an illumination angle and area of the LED lamp is limited.
What is needed, therefore, is an LED lamp with a heat dissipation device, which has a great heat dissipating capability. Furthermore, the heat dissipation device has a unique design, whereby the LED lamp can have a larger illumination angle and area.
An LED lamp includes a heat sink, a plurality of vapor chambers mounted on the heat sink and an LED module mounted on the vapor chambers. The LED module includes a plurality of printed circuit boards with a plurality of LEDs arrayed thereon. The heat sink includes a base, a plurality of fins extending from a first surface of the base and a triangular ridge formed on a second surface opposite to the first surface of the base. The vapor chambers are mounted on the ridge of the base. The LEDs over two lateral sides of the ridge are oriented slantwise outwardly thereby increasing an illuminating angle and area of the LED lamp.
Other advantages and novel features will become more apparent from the following detailed description of preferred embodiments when taken in conjunction with the accompanying drawings, in which:
Many aspects of the present embodiments can be better understood with reference to the following drawings. The components in the drawings are not necessarily drawn to scale, the emphasis instead being placed upon clearly illustrating the principles of the present embodiments. Moreover, in the drawings, like reference numerals designate corresponding parts throughout the several views.
Referring to
The heat sink 10 comprises a base 12, a plurality of fins 14 extending from a bottom surface of the base 12 and a triangular ridge 15 formed on a top surface of the base 12. The base 12 has a substantially rectangular shape. The fins 14 extend downwardly from the bottom surface of the base 12 and perpendicular to the base 12. The fins 14 extend along a longitudinal direction and parallel to each other. A plurality of longitudinal channels 140 are defined between every two adjacent fins 14 and parallel to long sides of the base 12. Heights of the fins 14 are gradually decreased along a direction away from a middle portion of the base 12 in such a manner that a top of the fins 14 has an arced configuration (clearly seen from
The ridge 15 is integrally formed on the top surface of the base 12. The ridge 15 extends along a direction parallel to the long sides of the base 12 and extends almost over an entire length of the base 12. A top end 151 of the ridge 15 is parallel to the fins 14 and positioned at a middle portion of the top surface of the base 12. A height of the ridge 15 is decreased along a direction from the top end 151 toward two lateral sides of the ridge 15. A plurality of steps 152 is formed on each of the two lateral sides of the ridge 15. The steps 152 are symmetric in respect to the top end 151 of the ridge 15. The slits 16 are located beside two lateral sides of the ridge 15.
The vapor chambers 20 comprises a first vapor chamber 21 and a plurality of second vapor chambers 22. The first vapor chamber 21 is a rectangular, bar-shaped and mounted on the top end 151 of the ridge 15. Each of the second vapor chambers 22 is triangular, prism-shaped. The second vapor chambers 22 are fitly attached on the steps 152 of the ridge 15, respectively. Each second vapor chamber 22 has an inclined surface (not labeled) over each of the steps 152 at the two lateral sides of the ridge 15 (clearly seen from
The LED module 30 comprises a plurality of printed circuit boards 31 and a plurality of LEDs 32 arrayed on the printed circuit boards 31. The printed circuit boards 31 each have a bar-shaped configuration and are mounted side by side on the inclined surfaces formed by the second vapor chambers 22 and on the first vapor chamber 21. Understandably, the printed circuit boards 31 on the second vapor chambers 22 can be replaced by two larger, single printed circuit boards, whereby the LEDs 32 can be bonded thereon in matrix.
In assembly, the first vapor chamber 21 is mounted on the top end 151 of the ridge 15, and the second vapor chambers 22 are fitly mounted on the steps 152 of the ridge 15. The printed circuit boards 31 of the LED module 30 thermally contact the vapor chambers 20, respectively. The printed circuit boards 31 are mounted on the inclined surfaces of the second vapor chambers 22 on the two lateral sides of the ridge 15, whereby an acute angle is defined between the printed circuit boards 31 on the second vapor chambers 22 and the top surface of the base 12. Thus, the light illuminated by the LEDs 32 of the LED lamp in accordance with the present invention has a larger illumination angle and illumination area.
In operation, referring to
As the printed circuit boards 31 on the two lateral sides of the ridge 15 are aslant to the top surface of the base 12, the light emitted by the LEDs 32 on the printed circuit boards 31 can project outwardly towards two lateral sides of the heat sink 10. Therefore, an irradiation area of the LED lamp in accordance with the present invention is enlarged.
It is believed that the present embodiments and their advantages will be understood from the foregoing description, and it will be apparent that various changes may be made thereto without departing from the spirit and scope of the invention or sacrificing all of its material advantages, the examples hereinbefore described merely being preferred or exemplary embodiments of the invention.
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2007 1 0124553 | Nov 2007 | CN | national |
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