1. Technical Field
The present invention relates to LED structures and, more particularly, to active blue light leakage preventing LED structures.
2. Description of Related Art
The earth is more and more consumed and damaged by people when the progress of living keeps advancing. Hence comes the need for the everlasting existence of the earth with the increasing demands for energy saving and environmental protection solution. Out of those demands, light-emitting diodes (LEDs) advantageously feature small physical volume, high brightness, low power consumption, and ease of use and replacement and become the most rapidly growing application.
Wherein the life span or life limit of LED, known as L70, is commonly defined as the light emitted by a LED reduces to about 70% of its stable emission value. However, in actual applications, the luminous efficiency of most white light LEDs will reduce even before L70 is reached due to the heat generated that the absorption and transformation of the fluorescent material decrease accordingly. The reduction in luminous efficiency then generates more heat. With such cycling mutual effect of heat and efficiency reduction keep going on and on, massive blue light is then inevitably leaked.
On the other hand, with the increasing usage of LEDs, more and more researches and papers about the destructive effect of blue light to human eyes are published to warn that irreversible damages will occur while human eyes are exposed to blue light for more than certain amount or for certain duration.
In view of the above, it has been a common goal and progress of the LED industries and the lighting industries to create a practical, effective and easy-to-use lighting LED structure that can rapidly, accurately and actively detect abnormal status and turn off the white light LED before massive heat is generated and great amount of blue light is emitted, and thus the protection of human eyes and life quality are thus desirably achieved, while at the same time informing the user the need of replacement of lighting device.
The present invention discloses active blue light leakage preventing LED structures. Each of the structure includes a circuit board, at least one blue light LED die, a photo detector and a wavelength transformation layer, wherein the electric circuit on the circuit board receives detection signal from the photo detector and turns off the said at least one blue light LED accordingly. With the implementation of the present invention, the active blue light leakage preventing LED structure turns off the white light LED when it reaches its usage life span limit thus avoiding the damage to human from the massive release of blue light.
The present invention provides an active blue light leakage preventing LED structure, comprising: a circuit board, comprising an upper surface; at least one blue light LED die, provided on the said upper surface and electrically connected to the said circuit board; a photo detector, provided on the said upper surface and electrically connected to the said circuit board, detecting a back scattering light of a wavelength transformation layer which results from the said blue light LED die and generating a detection signal; and a wavelength transformation layer, provided on the said upper surface, covering the said blue light LED die and the said photo detector; wherein the circuit of the said circuit board detects the said detection signal and turns off the said blue light LED die accordingly.
The present invention further provides an active blue light leakage preventing LED structure, comprising: a circuit board, comprising an upper surface; at least one blue light LED die, provided on the said upper surface and electrically connected to the said circuit board; a photo detector, provided on the said upper surface and electrically connected to the said circuit board, detecting a back scattering light of a wavelength transformation layer which results from the said blue light LED die and generating a detection signal; and a wavelength transformation layer, provided and covering a light emitting surface of the said blue light LED die; wherein the circuit of the said circuit board detects the said detection signal and turns off the said blue light LED die accordingly.
Implementation of the present invention at least involves the following inventive steps:
1. The need of complicated process or complicated equipment is not required, thus reduces implementation cost.
2. Capable of turning off the blue light LED die in time to prevent massive leakage of blue light to endanger an user.
3. Actively turn off blue light LED die to inform the user the need of replacement of lighting device, enables applications of smart controls.
The features and advantages of the present invention are detailed hereinafter with reference to the preferred embodiments. The detailed description is intended to enable a person skilled in the art to gain insight into the technical contents disclosed herein and implement the present invention accordingly. In particular, a person skilled in the art can easily understand the objects and advantages of the present invention by referring to the disclosure of the specification, the claims, and the accompanying drawings.
The invention as well as a preferred mode of use, further objectives and advantages thereof will be best understood by reference to the following detailed description of illustrative embodiments when read in conjunction with the accompanying drawings, wherein:
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Further, the phosphor powder layer used as the wavelength transformation layer 40 can be a yellow color phosphor powder layer, a red-green mixed color phosphor powder layer, or an orange-green mixed color phosphor powder layer.
The aforesaid back scattering light received by the photo detector 30 is a portion of the blue light emitted by the blue light LED die 20 and reflected by the wavelength transformation layer 40 toward the photo detector 30.
When the detected back scattering light reduces to a value below a predetermined threshold after a period of time of usage, the active blue light leakage preventing LED structure 100 is about to radiate large amount of blue light, wherein the temperature of the wavelength transformation layer 40 is greatly raised thus reduces enormously the light mixing function to leak massive quantity of blue light.
With the implementation of the photo detector 30 on the upper surface 11 of the circuit board 10, the back scattering light inside the active blue light leakage preventing LED structure 100 can always be detected, thus, the photo detector 30 actively generates a detection signal for the electrical circuit on the circuit board 10 to turn off the blue light LED die 20 accordingly, preventing unnecessary damage to users.
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Wherein the said packaging lens 50 or the said wavelength transformation layer 40 can be glued on the upper surface 11 of the circuit board 10 with a gasket.
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In this embodiment, the features and the relationships of the circuit board 10, the blue light LED die 20 and the photo detector 30 of the active blue light leakage preventing LED structure 200 are the same as in the embodiment of the active blue light leakage preventing LED structure 100 that requires no further descriptions.
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Moreover, with the implementation of the photo detector 30 on the upper surface 11 of the circuit board 10, the active blue light leakage preventing LED structure 200 is also capable of detecting the back scattering light of the wavelength transformation layer which results from the blue light LED die 20 inside. When the blue light LED die 20 reaches its usage life span limit, the detected back scattering blue light reduces to a value below a predetermined threshold after a period of time of usage and the active blue light leakage preventing LED structure 100 is about to radiate large amount of blue light, wherein the temperature of the wavelength transformation layer 40 is greatly raised thus reduces enormously the light mixing function to leak massive quantity of blue light, the photo detector 30 actively generates a detection signal for the electrical circuit on the circuit board 10 to turn off the blue light LED die 20 accordingly, thus preventing unnecessary damage to an user.
That is to say, with the photo detector 30 implemented inside, both the active blue light leakage preventing LED structure 100 and the active blue light leakage preventing LED structure 200 are embodiments achieving the specific features or the inventive steps as stated above, wherein the active blue light leakage preventing LED structure 100 or the active blue light leakage preventing LED structure 200 can be a white light LED structure.
The embodiments described above are intended only to demonstrate the technical concept and features of the present invention so as to enable a person skilled in the art to understand and implement the contents disclosed herein. It is understood that the disclosed embodiments are not to limit the scope of the present invention. Therefore, all equivalent changes or modifications based on the concept of the present invention should be encompassed by the appended claims.
Number | Date | Country | Kind |
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TW105107096 | Mar 2016 | TW | national |