JP4527230B2 - Surface-emitting LED light source - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a surface-emitting LED light source that uses an LED element to emit surface light.
[0002]
[Prior art]
FIG. 8 is a plan view of a planar LED light source disclosed in, for example, JP-A-7-176794, and FIG. 9 is a cross-sectional view of FIG.
FIG. 8 is a plan view of the light guide plate 2 of the planar light source of the present invention as viewed from the fluorescent scattering layer 23 side. In FIG. 8, 21 is a light guide plate, 1 is a blue LED element embedded in the end face of the light guide plate 21, 23 is a fluorescent scattering layer, and a mixture of fluorescent material and white pigment is applied. In FIG. 9, 26 is a scattering reflection layer provided on the second main surface side of the planar light source shown in FIG. 8, and 27 is a base. The scattering reflection layer 26 and the base 27 form a reflection plate. . Reference numeral 25 denotes a light diffusing plate provided on the first main surface side and having an uneven surface, and 24 is a reflection film.
[0003]
In this configuration, as shown in FIG. 9, the light emitted from the blue LED element 1 is partially radiated to the outside other than the light guide plate 21, but most of the light repeatedly undergoes total reflection inside the light guide plate 21. While reaching the end face of the light guide plate 21. At the end face, the light is reflected by the reflective film 24 and repeats total reflection. At this time, a part of the light is scattered by the fluorescent scattering layer 23 provided on the second main surface side of the light guide plate 21, and a part of the light is absorbed by the fluorescent material, and simultaneously wavelength-converted and emitted. The light color emitted from the light diffusing plate 25 of the light guide plate 21 is perceived by the eyes as a synthesized color of these lights.
[0004]
For example, in a planar light source provided with a fluorescent scattering layer 23 made of a yellow fluorescent pigment and a white pigment, the color emitted from the blue LED element 1 is felt white.
[0005]
[Problems to be solved by the invention]
However, the surface-emitting light source using the above-described conventional LED element needs to obtain surface emission by using the light guide plate 21 and entering the LED element light from the end of the light guide plate 21, or in other words, the surface portion. When the light is incident from the end, it emits a large area, but its light intensity is weak, and it is difficult to realize it for general illumination. On the other hand, when light is directly incident from the surface, there is a problem that unevenness of light occurs, that is, the local light surface of the LED element is easily seen, and it is difficult to obtain uniform surface light emission.
[0006]
Moreover, when using an ultraviolet LED element, it is necessary to take measures to prevent ultraviolet rays from leaking to the outside.
[0007]
SUMMARY OF THE INVENTION The present invention has been made to solve the above-described problems, and an object thereof is to provide a surface-emitting LED light source that is uniform, has high emission intensity, and does not leak ultraviolet rays even when an ultraviolet LED element is used. And
[0008]
[Means for Solving the Problems]
LED surface emitting LED light source according to the invention, for irradiating the phosphor provided on the inner surface, a box-shaped having at least opening in one direction is opened, the trough-shaped or dome-shaped reflector, the phosphor An element, a translucent body covering the opening of the reflector, a transparent electrode embedded in the translucent body, and installed in the vicinity of the opening, directly contacting the transparent electrode and supplying power to the transparent electrode A power connector for supplying power, and the LED element is supplied with power from the transparent electrode .
[0010]
A plurality of LED elements are provided along the end of the opening of the reflector .
[0011]
In addition, a plurality of LED elements are provided in the central part of the light transmitting body on the reflector side .
[0012]
Further, the translucent body has a characteristic of not transmitting a specific wavelength or a specific wavelength range.
[0013]
DETAILED DESCRIPTION OF THE INVENTION
Embodiment 1 FIG.
1 is a partially broken perspective view of a surface-emitting LED light source showing Embodiment 1 of the present invention, and FIG. 2 is a cross-sectional view of FIG. In the figure, reference numeral 10 denotes a box body whose front side is open, 3 is a bowl-shaped reflector having a phosphor 4 provided on the inner surface of the box body 10 and having a concave arc shape in cross section, and 1 is one opening end of the reflector 3. A plurality of LED elements provided in a line along the portion 3 a are mounted on the substrate 2. Reference numeral 5 denotes a planar light-transmitting body that covers the opening of the reflecting body 3 and transmits light radiated from the LED element 1 and reflected by the reflecting body 3. Reference numeral 5 a denotes a light emitting surface of the light-transmitting body 5.
Reference numeral 7 denotes a transparent electrode embedded in the translucent body 5, which is connected to the power connector 9. The LED element 1 is connected to a power source (not shown) through a power connector 9 and a transparent electrode 7.
[0014]
The phosphor 4 uses, for example, YAG when the emission of the LED element 1 is blue light, and when it emits ultraviolet light, the phosphor (R) that emits red light when irradiated with ultraviolet light and the phosphor (G) that emits green light. And a phosphor (B) that emits blue light are used. For example, the phosphor (R) uses YVO ₄ : Eu, Bi having a peak wavelength of 619 nm, and the phosphor (G) uses, for example, Y ₂ SiO ₅ Ce, Tb having a peak wavelength of 543 nm. For example, BaMgAl ₁₆ O ₂₇ : Eu having a peak wavelength of 450 nm is used.
YAG wavelength-converts blue light into yellow visible light. At this time, a part of the light is reflected in blue without being wavelength-converted.
[0015]
In this configuration, first, when power is supplied to the LED element 1 via the power connector 9 and the transparent electrode 7, the LED element 1 emits blue light or ultraviolet light and is reflected by the reflector 3. When the LED element 1 is blue radiated light by the phosphor 3, the wavelength of the LED element 1 is converted to yellow visible light, and the light is diffused and emitted from the translucent body 5. At this time, a part of the blue radiated light is not wavelength-converted and is radiated out of the translucent body 5 as blue. This wavelength-converted yellow light and blue light that has not been wavelength-converted are combined and felt as white light.
[0016]
When the LED element 1 emits ultraviolet light, the phosphor 4 converts the wavelength into red, green, and blue visible light, and diffuses and emits the light from the translucent body 5. These lights are combined and felt as white light. In this case, the translucent member 5 that does not transmit ultraviolet rays is used.
[0017]
Moreover, the light color radiated | emitted from the transmissive body 5 can be changed by adjusting the film thickness or content or content ratio of the phosphor 4.
[0018]
Next, when the translucent body 5 is disconnected for some reason during use of the surface emitting LED light source, the energization of the transparent electrode 7 embedded in the translucent body 5 is cut off, so that Energization is also cut off, improving safety.
[0019]
Further, when the LED element 1 emits ultraviolet rays, it is possible to prevent ultraviolet rays from being emitted from the surface emitting LED light source.
[0020]
As described above, it is possible to obtain planar and uniform light from the translucent body 5, and even if the translucent body 5 is removed or partly missing for some reason, the LED element 1 Radiation is stopped, safety is ensured, and radiation of ultraviolet rays to the outside can always be prevented even when ultraviolet LEDs are used.
The phosphor 4 may be applied to the reflector 3 or may be in close contact with the reflector 3 in the form of a sheet.
In addition, the light-transmitting body 5 is not only transparent, but also can have various types of light by making it diffusible or colored by surface finishing.
[0021]
Embodiment 2. FIG.
FIG. 3 is a sectional view of a surface-emitting LED light source showing Embodiment 2 of the present invention. In the first embodiment, a plurality of LED elements 1 are provided in a line along one opening end 3a of the reflector 3, but the LED element 1 is provided with two openings of the reflector 3 as shown in FIG. It is provided in a row along the end portions 3a and 3b. In this configuration, the planar light emission intensity from the translucent body 5 can be made more uniform and stronger.
In addition, as shown in FIG.4, FIG.5, FIG.6, it is good also considering the reflector 3 as a flat plate shape, or combining several planes. Although not shown, the reflector 3 may be formed in a dome shape.
[0022]
Embodiment 3 FIG.
FIG. 7 is a cross-sectional view of a surface-emitting LED light source showing Embodiment 3 of the present invention. As shown in FIG. 7, the LED element 1 is provided on the translucent body 5 at the center of the opening of the reflector 3n, and the intrusion angle (solid angle) from the LED element 1 to the effective portion of the reflector 3 is small. Since it becomes larger than Embodiment 1 and Embodiment 2, the efficiency which injects into the reflector 3 of the radiation | emission from LED element 1 improves, and it can be set as an efficient surface emitting LED light source.
[0023]
【The invention's effect】
As described above, according to the present invention, a box-shaped, bowl-shaped or dome-shaped reflector having a phosphor on the inner surface and opened in at least one direction, an LED element that irradiates the reflector, and the reflection Since the light-transmitting body covering the opening of the body is provided, a uniform planar light-emitting light source can be obtained.
[0024]
Further, since a plurality of LED elements are provided along the opening end of the reflector, the planar light emission intensity can be made more uniform and stronger.
[0025]
In addition, since a plurality of LED elements are provided in the central portion of the light transmitting body on the reflector side, the light emission intensity and light emission efficiency that emerge from the light transmitting body can be increased.
[0026]
In addition, since the translucent body is provided with means for shutting off the power supply of the LED element, if the translucent body is removed for some reason or a part of it is missing, the energization to the LED element is interrupted and safety is improved. To do.
[0027]
Moreover, since the translucent body has a characteristic of not transmitting a specific wavelength or a specific wavelength range, it is possible to prevent the ultraviolet light from being emitted to the outside even when an LED that emits the ultraviolet light is used.
[Brief description of the drawings]
FIG. 1 is a perspective view of a surface-emitting LED light source showing Embodiment 1 of the present invention.
FIG. 2 is a cross-sectional view of a surface-emitting LED light source showing Embodiment 1 of the present invention.
FIG. 3 is a cross-sectional view of a surface emitting LED light source showing Embodiment 2 of the present invention.
FIG. 4 is a cross-sectional view of a surface-emitting LED light source showing Embodiment 2 of the present invention.
FIG. 5 is a cross-sectional view of a surface-emitting LED light source showing Embodiment 2 of the present invention.
FIG. 6 is a cross-sectional view of a surface-emitting LED light source showing Embodiment 2 of the present invention.
FIG. 7 is a cross-sectional view of a surface-emitting LED light source showing Embodiment 3 of the present invention.
FIG. 8 is a plan view of a conventional surface-emitting LED light source.
FIG. 9 is a cross-sectional view of a conventional surface-emitting LED light source mounted.
[Explanation of symbols]
10 box, 3 reflector, 1 LED element, 2 substrate, 5 translucent body, 7 transparent electrode, 9 power connector.

Claims (4)

A box-like, bowl-like or dome-like reflector having a phosphor provided on the inner surface and an opening having at least one opening;
An LED element for irradiating the phosphor;
A translucent body covering the opening of the reflector;
A transparent electrode embedded in the light transmitting body;
A power connector that is installed near the opening and that directly contacts the transparent electrode to supply power to the transparent electrode;
With
The LED element is supplied with power from the transparent electrode. A surface-emitting LED light source. LED device surface emitting LED light source according to claim 1, wherein the provided plurality along the opening end portion of the reflector. LED device according to claim 1 surface-emitting LED light source, wherein the provided plurality in a central portion of the reflector side of the transparent body. The surface-emitting LED light source according to any one of claims 1 to 3 , wherein the translucent body has a characteristic of not transmitting a specific wavelength or a specific wavelength range.

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