Patent Application
20080174247
(A) Field of the Invention
The present invention relates to a high-power light emitting diode (LED) lamp and the LED device thereof.
(B) Description of the Related Art
In recent years, white LEDs have become a very popular new product attracting widespread attention all over the world. Because white LEDs offer the advantages of small size, low power consumption, long life, and quick response speed, the problems caused by using conventional incandescent bulbs can be solved. Therefore, the applications of LEDs in backlight sources of displays, mini-projectors, illumination, and car lamp sources are becoming increasingly important in the market.
At present, Europe, the United States, Japan, and other countries have a consensus with respect to energy conservation and environmental protection, and in the new century are actively developing the white LED as a new light source for illumination. Currently, energy is imported in many countries, so it is worthwhile to develop the white LED in the illumination market. Based on the evaluation of experts, if all the incandescent lamps in Japan are replaced with white LEDs, electric power generated by two power plants could be saved each year and the indirectly reduction in fuel consumption could be total one billion liters. Furthermore, carbon dioxide created during electrical power generation is also reduced, thereby reducing the greenhouse effect. Therefore, countries in Europe, America, and Japan have devoted a lot of manpower to white LED development. It is predicted that white LEDs can fully replace conventional illuminating apparatuses within ten years.
Although LEDs represent the future of illumination applications, many problems still remain unsolved. For example, with a high-power LED for illumination, only about 15-20% of input power is converted into light, and the remaining 80-85% is converted into heat. If heat is not dissipated to the environment efficiently, the temperature of the LED die will be too high, thus influencing the light emitting intensity and service life of the LED die. Therefore, heat management of LED devices is becoming a crucial issue.
As shown in
However, the above traditional LED lamp needs further lens or reflective surface to effectively emit LED lights, resulting in an increase in cost. In addition, the LED device is disposed on an insulation plate; therefore the heat cannot be effectively dissipated. Consequently, the LED lamp would soon be degraded.
According to the design, a traditional LED lamp is difficult to design with both a small size and a high efficiency of heat dissipation, and the LED device cannot disposed at the vicinity of the focal point (bottom) of the lamp housing. Instead, the LED device is disposed at a position exceeding 50% of total depth of the lamp housing, i.e., HL/HT>0.5, where HT is the total depth of the cuplike lamp housing, and HL is the distance between a surface of the LED device and the bottom of the cuplike lamp housing. Because the LED device tends to be placed too high, the LED device without an adjustment lens would scatter and cannot be used. But the LED device with a lens would increase the cost and be harmful to the performance of heat dissipation. Moreover, if the LED device is damaged, the entire LED lamp has to be replaced, so it is not cost-effective.
The present invention is directed to providing an LED lamp and the LED device thereof. The LED lamp has a simple structure without a lens or a lamp cover, and has superior heat dissipation efficiency. Consequently, the LED lifetime can be increased, and the cost can be reduced. Moreover, the LED device of the present invention can be removed from the LED lamp, so that only the LED device needs to be replaced if it is damaged, thus the maintenance cost can be reduced.
The high-power LED lamp comprises a cuplike lamp housing, an LED device, an adapter and a circuit board. The inner surface of the cuplike lamp housing is a reflective curved surface configured to reflect the lights from the LED device disposed at the bottom of the cuplike lamp housing, so as to improve the lighting efficiency of the LED device. The adapter is configured to secure the LED device, and the circuit board is configured to provide power to the LED device. If HT is the total depth of the cuplike lamp housing, and HL is the distance between a surface of the LED device and the bottom of the cuplike lamp housing, the disposition of the LED device has the relation: 0.05<HL/HT<0.35.
Preferably, the inner surface of the adapter has female threads and the side surface of the LED device has corresponding male threads, by which the LED device can be secured with the adapter. The circuit board comprises a conductive point connected to the bottom of the LED device serving as a positive electrode, whereas the male threads on the side surface of the LED device serve as a negative electrode. A damaged LED device can be easily replaced via the configuration of male and female threads, so it is not necessary to replace the entire LED lamp.
The LED device is a stacked structure including an LED package device, a ring member and an electrode plate. The LED package device comprises LED dies and a metal base connected to the first electrode of the LED die. The ring member is disposed below the LED package device and having male threads on a side surface. The electrode plate is disposed below the ring member and is provided with a rod at the center thereof. The rod penetrates through the ring member and the center hole of the metal base of the LED package device. The top of the rod is connected to the second electrode of LED die. The electrode plate and the ring member serve as the positive electrode and the negative electrode, respectively, of the LED device.
In addition to the simplicity of the high-power LED lamp, the adapter and cuplike lamp housing are capable of dissipating heat. Moreover, the lens or lamp cover is not needed, so that the efficiency of heat dissipation can be further improved, thereby resolving the heat dissipation issue of the high-power LED.
Referring to
An LED device normally can withstand 3.4 V and 350 mA, so that the LED device needs the circuit board 24 for voltage transformation because a traditional lamp of halogens (MR-16) uses 12V or 110V. The circuit board 24 has two plugs 25 to be in connection with a power source, and a conductive point 241 serving as connection point to the positive electrode of the LED device 27. The circuit board 24 associated with the heat-dissipation glue member 23 complies with the inner contour of the lamp base 22 and is disposed inside the lamp base 22. The inner surface of the adapter 26 is provided with female threads 261, which correspond to the male threads 271 of the LED device 27 for securing the LED device 27. Because the female threads are in direct contact with the LED device 27, heat dissipation of the LED device 27 can be further improved especially if the adapter 26 is made of metal.
Referring to
The lens or lamp cover is not needed for the high-power LED lamp 20 or 30, and consequently the LED device 27 is exposed to air. Also, the adapter 26, the cuplike lamp housing 21 and heat-dissipation glue member 23 are all capable of heat dissipation. Therefore, the heat generated by the LED device 27 can be dissipated effectively, and thus the lifetime of the LED device 27 increases. Moreover, the LED device 27 can be replaced directly if damaged. It is not necessary to replace the entire LED lamp 20 or 30, so that maintenance costs can be significantly reduced.
The above-described embodiments of the present invention are intended to be illustrative only. Numerous alternative embodiments may be devised by those skilled in the art without departing from the scope of the following claims.
| Number | Date | Country | Kind |
|---|---|---|---|
| 096201379 | Jan 2007 | TW | national |
