Patent Application
20180266651
The present invention relates to a light emitting diode lamp.
A light emitting diode (LED) is a semiconductor device that can emit light. When an LED is electrified, the electrons and the holes in the LED will recombine, and then the electrons will fall from a higher energy level to a lower energy level, and the photos will be released during the process. As compared to an incandescent light bulb, which emits light by thermal radiation, an LED has higher luminous efficiency, and is advantageous for energy conservation and environmental protection.
In light of the above, the present invention provides a light emitting diode plane source lamp, comprising a substrate; four side plates set on four sides of the substrate and perpendicular to the substrate; a plurality of circuit boards symmetrically set on the substrate and connected to each other in parallel; a plurality of light emitting diodes set on each circuit board and arranged as a matrix on the circuit board; a power supplier set on the substrate and providing electrical power to the light emitting diodes; and a fogging film set on the side plates and opposite to the substrate. The fogging film scatters the lights of the light emitting diodes to provide a uniform plane source.
Besides, in further embodiments of the present invention, it is noted that the fogging film has a non-linear relation between an illuminance of its incident surface and a luminous exitance (or luminous emittance) of its emergent surface, and that the luminous exitance of the fogging film can be optimized by adjusting parameters including a radiant flux of each light emitting diode, a distance between any two adjacent light emitting diodes and a height between each light emitting diode and the fogging film, on purpose of energy conservation and environmental protection.
Other objects, novel features and advantages of the present invention will become more apparent from the following detailed description when taken in conjunction with the accompanying drawings.
Different embodiments of the present invention are provided in the following detailed description. These embodiments are not meant to limiting. It is possible to make modifications, replacements, combinations, separations or designs with the features of the present invention to apply to other embodiments.
In this embodiment, the light emitting diode plane source lamp 1 mainly includes a substrate 10, four side plates 11, four circuit boards 20, a plurality of light emitting diodes 30, a power supplier 40 and a fogging film 50.
The substrate 10 is rectangular, so that it can be easily installed in a ceiling or a wall. The four side plates 11 are set on four sides of the substrate 10, respectively, and they are perpendicular to the substrate 10. The fogging film 50 is set on the four side plates 11 and opposite to the substrate 10. Therefore, the substrate 10, the four side plates 11 and the fogging film 50 form a container space.
Selectively, the setting of fogging film 50 can be achieved by setting a frame 60 on the four side plates 11, and then inserting the fogging film 50 into the frame 60. As shown in
In measurement, the temperature of the circuit board of the light emitting diode plane source lamp 1 of the present invention is 25° C. to 30° C., which is lower than the temperature of the prior art LED tube. This shows an advantage provided by the present invention.
In the container space, four circuit boards 20 are fixed on the substrate 10, and they are horizontally symmetric and vertically symmetric. They are electrically connected to each other in parallel and are connected to a power supplier 40 by wires 41. The power supplier 40 can be connected to supply mains by a plug wire 13.
A plurality of light emitting diodes 30 are set on each circuit board 20 and arranged as a matrix on each circuit board. In this embodiment, the light emitting diodes 30 on each circuit board 20 are arranged as a matrix of 7 rows and 5 columns. In other embodiments, the matrix can have a different number of rows and a different number of columns. There is a distance D (which can be defined in a vertical direction or a horizontal direction) between two adjacent light emitting diodes 30. The light emitting diode 30 can emit white light, warm light or the combination thereof.
Each light emitting diode 30 has a radiant flux W. Each light emitting diode 30 can emit light in a range of angles defined by Lambertian distribution or Gaussian distribution.
Taking a matrix of 7 rows and 5 columns for example,
It is noted that, since the circuit boards 30 are not adhesively assembled on the substrate 10, and become removable from the container space, replacements of the circuit boards 30 is possible once any of them is disabled, and the disabled one can be recycled. This is helpful for environmental protection.
In the present invention, it is noted that, the fogging film 50 has a non-linear relation between an illuminance E of the incident surface 51 and a luminous exitance M of the emergent surface 52. It is noted that, the illuminance E is defined as the luminous flux per unit area received by the incident surface 51 of the fogging film 50, and the luminous exitance M is defined as the luminous flux per unit area emitted by the emergent surface 52 of the fogging film 50. Such non-linear relation cannot be expressed as an analytic solution, but can be expressed with characteristic of maximum.
In particular, the parameters determining the illuminance E of the incident surface includes the radiant flux W of each light emitting diode 30, the distance D spacing out any two adjacent light emitting diodes 30, and the height H between the light emitting diodes 30 and the fogging film 50, because the illuminance E is obtained by integrating the luminous flux with respect to the incident angles on a unit area, wherein the luminous flux is proportional to the radiant flux W, and the incident angle is the arctangent of a ratio of the distance D and the height H.
Moreover, as discussed above, in the present invention, it is noted that the fogging film 50 has a non-linear relation between the illuminance E of the incident surface 51 and the luminous exitance M of the emergent surface 52, and thus the luminous exitance M of the superposition of the lights emitted from the light emitting diodes 30 passing through the fogging film 50 can be expressed as a non-linear function F with respect to the radiant flux W, the distance D or the height II, and that the non-linear function F converges to a maximum U. That is to say, the non-linear function F is a convergent function and does not diverge to infiniteness. Furthermore, at least one part of the non-linear function F is a quadratic function.
It is noted that, the maximum U of the non-linear function F depends on the material of the fogging film 50, or in other words, fogging films 50 of different materials have different maxima U. In this embodiment, the fogging film 50 is a polycarbonate (PC) film. In other embodiments, the fogging film 50 can be an acrylic film.
Therefore, in the present invention, the radiant flux W, the distance D or the height H is adjusted such that the non-linear function F becomes the maximum U. Accordingly, the present invention obtains that, the ratio of the radiant flux W:the distance D:the height is preferred to be 0.2 Watt:1.5 cm:3 cm, so that the non-linear function F can be the maximum U. Therefore, for the light emitting diodes 30, it is preferred that the radiant flux W is 0.2 Watt, the distance D is 1.5 cm and the height H from a light emitting diode 30 to the fogging film 50 is 3 cm; or the radiant flux W is 0.3 Watt, the distance D is 2.25 cm, the height H from a light emitting diode 30 to the togging film 50 is 4.5 cm, and so on. The height H is preferably 0.5 to 5 cm.
In measurement, the luminous exitance M of the light emitting diode plane source lamp 1 of the present invention is 800 lx (lx=lx·m−2), which conforms to the indoor lighting standards.
It is important to have the aforementioned ratio relation. Since the light emitting diodes have to be arranged as a matrix to provide a plane source, if the aforementioned ratio relation is applied, the luminous efficacy of the plane source lamp can be increased. In contrast, if another ratio relation instead of the aforementioned ratio relation is applied, the luminous efficacy of the plane source lamp cannot be optimized, resulting in energy waste and waste heat.
One circuit board 20 having 35 light emitting diodes 30 only consumes electrical power of 5 Watts up to 10 Watts, preferably, 7.5 Watts, and in this embodiment, two circuit boards 20 each having 35 light emitting diodes 30 only consume electrical power of 15 Watts. It shows that the present invention saves more electrical power than the prior art does. The temperature of the circuit board is about 25° C., which is lower than the temperature of the prior art LED tube.
In measurement, three circuit boards 20 each having 35 light emitting diodes 30 only consumes electrical power of 20 Watts. It shows that the present invention saves more electrical power than the prior art does. The temperature of the circuit board is about 25° C., which is lower than the temperature of the prior art LED tube.
In conclusion, the light emitting diode plane source lamp of the present invention can provide uniform plane source. In addition, in the present invention, it is noted that the fogging film 50 has a non-linear relation between the illuminance E of the incident surface and the luminous exitance M of the emergent surface, and that the luminous exitance M of the fogging film 50 can be optimized by adjusting relevant parameters.
Although the present invention has been explained in relation to its preferred embodiments, it is to be understood that many other possible modifications and variations can be made without departing from the spirit and scope of the invention as hereinafter claimed.
| Number | Date | Country | Kind |
|---|---|---|---|
| 106109151 | Mar 2017 | TW | national |
