Patent Grant
8011814
The present invention relates to a illuminating device.
At present, cold cathode fluorescent lamps and light-emitting diodes (LEDs) are popularly used as illuminating devices.
Generally, heat produced by the illuminating device can be transferred via air convection and dissipated into the external environment. However, the air has a relatively small thermal conductivity coefficient, and, as such, heat dissipation is slow. Eventually, the heat accumulated around the illuminating device will influence the light intensity of the LED, thereby reducing the operation life thereof.
Therefore, what is needed, is an illuminating device having high heat dissipation efficiency.
An illuminating device includes a circuit board, a light source, and a thermoelectric cooler. The circuit board has a first surface and a second surface at an opposite side of the circuit board to the first surface. The light source is electrically mounted on the first surface of the circuit board. The thermoelectric cooler is attached on the second surface of the circuit board.
Many aspects of the present illuminating device 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 illuminating device. Moreover, in the drawings, like reference numerals designate corresponding parts throughout the several views.
Referring to
In the present embodiment, the at least one light source 11 consists a plurality of LEDs. The plurality of LEDs is selected from the group consisting of white LED, green LED, red LED, and blue LED.
The circuit board 12 includes a first surface 120 and a second surface 122 facing away from the first surface 120. The plurality of light sources 11 is electrically attached to the first surface 120 of the circuit board 12. In the present embodiment, the circuit board 12 is a ceramic substrate printed board. In alternative embodiments, the circuit board 12 can be a glass fiber board.
In the present embodiment, the TEC 13 includes a condensation section 131, a first evaporation section 132a and a second evaporation section 132b. The first evaporation section 132a and the second evaporation section 132b are opposite to the condensation section 131. A p-type semiconductor 134 is disposed between the condensation section 131 and the first evaporation section 132a. An n-type semiconductor 133 is disposed between the condensation section 131 and the second evaporation section 132b. The condensation section 131 of the TEC 13 is adjacent to the second surface 122 of the circuit board 12.
In operation, the TEC 13 is connected to a DC voltage 19. In detail, the n-type semiconductor 133 is connected to the positive pole, and the p-type semiconductor 134 is connected to the negative pole. The TEC 13 is a solid-state active heat pump which transfers heat from the condensation section 131 to the evaporation sections (132a, 132b), by consumption of electrical energy. The effectiveness of the pump for transferring the heat away from the condensation section 131 is totally dependent upon the amount of current provided and the efficiency of the evaporation sections (132a, 132b).
In order to dissipate heat more efficiently, the illuminating device 10 can further comprise a heat sink 15 attached to the first evaporation section 132a and the second evaporation section 132b. The heat sink 15 includes a substrate 151 and fins 152 formed on the substrate 151. The substrate 151 is formed on the first evaporation section 132a and the second evaporation section 132b.
The illuminating device can further include a first ceramic board 1310 and a second ceramic board 1320. The first ceramic board 1310 is formed on the second surface 122 of the circuit board 12, and the condensation section 131 is formed on the first ceramic board 1310, i.e., the first ceramic board 1310 is sandwiched between the circuit board 12 and the condensation section 131. The second ceramic board 1320 is formed on the first evaporation section 132a and the second evaporation section 132b. That is, the TEC 13 is sandwiched between the first ceramic board 1310 and the second ceramic board 1320. Since the ceramic boards 1310 and 1320 have good thermal conductivity and insulating property, the heat generated by the LEDs 11 can be well conducted to the TEC 13, meanwhile, the circuit board 12 and the TEC 13, the TEC 13 and the heat sink 15, are insulated from each other separately.
Referring to
The control circuit 172 includes a comparing unit 1720 and a control unit 1722. The comparing unit 1720 is utilized to compare the heat generated by the LEDs 11 with a predetermined temperature T. The value of the predetermined temperature T is stored in the comparing unit 1720. The TEC 13 has two working mode, mode I (lower temperature) and mode II (higher temperature). Referring to
In summary, the TEC 13 can work at mode I and mode II in accordance with the thermal radiation emitted from the LEDs.
While the present invention has been described as having preferred or exemplary embodiments, the embodiments can be further modified within the spirit and scope of this disclosure. This application is therefore intended to cover any variations, uses, or adaptations of the embodiments using the general principles of the invention as claimed. Further, this application is intended to cover such departures from the present disclosure as come within known or customary practice in the art to which the invention pertains and which fall within the limits of the appended claims or equivalents thereof.
| Number | Date | Country |
|---|---|---|
| 1957296 | May 2007 | CN |
| 260352 | Oct 1995 | TW |
| I252900 | Apr 2006 | TW |
| Number | Date | Country | |
|---|---|---|---|
| 20090154175 A1 | Jun 2009 | US |
