The present disclosure relates to LED (light emitting diode) lamps, and more particularly to an LED illumination device having adjustable light intensity.
LEDs have many beneficial characteristics, including low electrical power consumption, low heat generation, long lifetime, small volume, good impact resistance, fast response and excellent stability. These characteristics have enabled the LEDs to be widely used as a light source in electrical appliances and electronic devices.
A conventional LED illumination device includes a plurality of LED packages and a light modulator electrically connecting the LED packages. The light modulator includes a filter, a frame supporting the filter and a rack guiding the frame sliding thereon. In use, the filter rotates relative to the frame and slides with the frame, and light emitted from the LED packages radiates to the filter and is filtered by the filter. Thus, the light intensity of the LED illumination device is adjusted.
Embodiments of an LED illumination device in accordance with the present disclosure will now be described in detail below and with reference to the drawings.
Referring to
In this embodiment, the minimal light intensity of the first lamp group 10 is equal to or larger than 20% of the largest light intensity of the first lamp group 10. The largest light intensity of the second lamp group 30 is less than 20% of the largest light intensity of the first lamp group 10.
Referring to
Referring to
In this embodiment, the switch 50 controls the first lamp group 10 or the second lamp group 30 on or off respectively to adjust the light intensity of the illumination device 100. Further, the first slide rheostat 13 and the second slide rheostat 33 can be operated to make the light intensity of the illumination device 100 vary in a large range.
The first lamp group 10 and the second lamp group 30 can have different color temperature. Each first LED 11 of the first lamp group 10 has a first color temperature, and each second LED 31 of the second lamp group 30 has a second color temperature. Alternatively, one of the first LED 11 has the first color temperature, the other first LED 11 of the first lamp group 10 has a third color temperature, and each second LED 31 of the second lamp group 30 has the second color temperature. In yet another alternative, each first LED 11 of the first lamp group 10 has the first color temperature, one of the second LED 31 has the second lamp group 30 has the second color temperature, and the other second LED 31 has a fourth color temperature.
It is understood, a package layer may envelope the package. The package layer is made of silicon or a mixture mixed by silicon and phosphor powder. It is to be further understood that even though numerous characteristics and advantages of the present embodiments have been set forth in the foregoing description, together with details of the structures and functions of the embodiments, the disclosure is illustrative only, and changes may be made in detail, especially in matters of shape, size, and arrangement of parts within the principles of the disclosure to the full extent indicated by the broad general meaning of the terms in which the appended claims are expressed
Number | Date | Country | Kind |
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201310317794X | Jul 2013 | CN | national |