JP2007005549A - White light emitting LED lamp - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a white light emitting LED lamp capable of emitting white light having good color rendering properties, particularly red reproducibility when used as illumination.
SOLUTION: A white light-emitting lamp 1 includes a plurality of phosphors 4 (a plurality of blue light-emitting phosphors and a green light-emitting phosphor) that emit light by being excited by ultraviolet rays, and an ultraviolet LED 2 that emits ultraviolet light and a red LED 3 that emits red light. It is the structure sealed with the transparent resin 5 containing.
[Selection] Figure 1

Description

  The present invention relates to a white light emitting LED lamp.

  Currently, there are mainly three types of white light emitting LED lamps that can emit white light. The first is a blue LED covered with a transparent resin containing a yellow light-emitting phosphor that emits yellow light by blue excitation (see Patent Document 1), or a blue LED that emits green light by blue excitation. This lamp package is covered with a transparent resin containing a green light-emitting phosphor and a red light-emitting phosphor that emits red light when excited by blue light. Blue light from a blue LED and yellow light from a yellow light-emitting phosphor excited thereby Some light sources are mixed or mixed with blue light from a blue LED and green light emitted from the green light-emitting phosphor and red light emitted from the red light-emitting phosphor.

  Second, the ultraviolet LED includes a blue light emitting phosphor that emits blue light by ultraviolet excitation, a green light emitting phosphor that emits green light by ultraviolet excitation, and a red light emitting phosphor that emits red light by ultraviolet excitation. This is a lamp package covered with a transparent resin. By mixing blue light from a blue light emitting phosphor, green light from a green light emitting phosphor and red light from a red light emitting phosphor excited by ultraviolet light from a blue LED. White light is obtained (see Patent Document 2).

The third one is a resin-sealed lamp in which three LED chips corresponding to each of blue, red, and green are mounted in a package, and each color LED emits light at the same time and is mixed to make white ( Patent Document 2).
JP 2004-55772 A (FIG. 8) JP 2001-111114 A

  However, among the three types of white light-emitting LED lamps described above, those that use red light-emitting phosphors are currently put into practical use as phosphors that emit red light and have high conversion efficiency to convert blue or ultraviolet light into red. Therefore, when used as illumination, red color reproduction is insufficient. Moreover, even if what produces white by light emission of a blue LED and light emission of a yellow light-emitting phosphor does not contain a red component, red reproduction is very low when applied to illumination.

  In addition, when using LED chips of three colors, blue, red, and green, each color LED has an excellent monochromatic peak, so that there is a problem that uneven color is likely to occur, and power is supplied to each of the three LEDs. There is also a problem that the cost increases because a circuit is required.

  Therefore, in view of the above-described problems of the prior art, the present invention emits white light with good color rendering, particularly red reproducibility, when a white light emitting LED lamp using a phosphor is used as illumination. An object of the present invention is to provide a white light-emitting LED lamp capable of achieving the above.

  In order to achieve the above object, in the white light emitting LED lamp of the present invention, the ultraviolet LED and the red LED are sealed with a transparent resin containing a plurality of blue light emitting phosphors and green light emitting phosphors that are excited by ultraviolet rays to emit light. It is characterized by that.

  In such a configuration, the blue light and green light emitted from the blue light emitting phosphor and the green light emitting phosphor by ultraviolet excitation and the red light from the red LED are mixed in the transparent resin, and as a result, white light is emitted from the lamp. It is emitted outside. In this way, the red emission spectrum is generated directly from the red LED instead of the very inefficient red-emitting phosphor, so that when the white light-emitting LED lamp of the present invention is used for illumination, red reproduction is achieved. Good sex. That is, a color closer to reality of an object including red is visible and color rendering is improved.

  As described above, according to the present invention, it is possible to provide a white light emitting LED that emits white light with good color rendering properties, particularly red reproducibility when used as illumination.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 is a schematic cross-sectional view showing the structure of a white light emitting LED lamp according to an embodiment of the present invention.

  As shown in FIG. 1, a white light-emitting lamp 1 is formed by sealing an ultraviolet LED 2 that emits ultraviolet light and a red LED 3 that emits red light by a transparent resin 5 including a plurality of phosphors 4 that are excited by the ultraviolet light to emit light. Structure. More specifically, the ultraviolet LED 2 and the red LED 3 are bonded and mounted with a gold wire 7 on the bottom surface of the concave package 6 made of plastic or ceramic, and the transparent resin 5 is filled in the concave portion of the package 6. The ultraviolet LED 2 and the red LED 3 are sealed. The LED mounting method is not limited to wire bonding as shown in the figure, and face bonding using ball bumps may be used. Moreover, the package 6 is not limited to the aspect of FIG. 1, and can take various shapes.

  As the material of the transparent resin 5, epoxy resin, polycarbonate, polystyrene, acrylic resin, or the like can be used.

  For example, a GaN / GaInN / GaN diode can be used as the ultraviolet LED 2. The red LED 3 can be, for example, an AlInGa-based, GaAsP-based, or GaAlAs-based LED.

  The phosphor 4 contained in the transparent resin 5 emits an emission spectrum that supplements the emission intensity in the wavelength band between the ultraviolet wavelength band emitted by the ultraviolet LED 2 and the red wavelength band emitted by the red LED 3. Therefore, as the phosphor 4, both a blue light-emitting phosphor that emits blue light with ultraviolet excitation and a green light-emitting phosphor that emits green light with ultraviolet excitation are used. Each of the blue light emitting phosphor and the green light emitting phosphor includes, for example, at least one element of Zn, Mg, Cd, and Be, and includes II-VI including at least one element of Se, S, Te, and O. And a semiconductor selected from the group consisting of a group III-V semiconductor containing at least one element of Ga, Al and In and containing at least one element of As, P and N.

  A plurality of blue light-emitting phosphors and green light-emitting phosphors are arranged in a dispersed state in the transparent resin 5. The plurality of blue light-emitting phosphors and green light-emitting phosphors are uniformly excited by the ultraviolet rays from the ultraviolet LED 2. It is good to arrange in the resin.

  The white light-emitting lamp 1 configured as described above can emit white light as follows. First, by applying a voltage to each of the ultraviolet LED 2 and the red LED 3, the ultraviolet LED 2 emits ultraviolet light, and the red LED 3 emits red light.

  The ultraviolet rays emitted from the ultraviolet LED 2 excite a plurality of blue-emitting phosphors and green-emitting phosphors as the plurality of phosphors 4 dispersedly arranged in the transparent resin 5. The blue light-emitting phosphor and the green light-emitting phosphor are excited by ultraviolet rays and emit blue light and green light, respectively.

  The blue light and green light emitted from the blue light emitting phosphor and the green light emitting phosphor and the red light from the red LED 3 are mixed in the transparent resin 5, and as a result, white light is emitted outside the lamp.

  In such a white light emitting LED lamp of the present embodiment, the red light emission spectrum is generated directly from the red LED 3 instead of the very inefficient red light emitting phosphor, so that white light with good red reproducibility is generated. Obtainable. Further, by controlling the light emission intensity of each of the LEDs 2 and 3, various white light can be emitted from white light with strong bluish light to white light with strong redness.

  As an embodiment different from the above, the ultraviolet LED 2 is replaced with a blue LED, and a YAG phosphor (yellow light-emitting phosphor or green light-emitting phosphor) that emits light by blue excitation is used as the phosphor 4 together with the blue LED. A white light emitting LED lamp having a structure in which a red LED is covered with a transparent resin containing a YAG phosphor is also conceivable, and in this case, as in the above-described embodiment, there is an effect that white light with good red reproducibility can be obtained. .

It is typical sectional drawing which shows the structure of the white light emitting LED lamp by embodiment of this invention.

Explanation of symbols

1 White LED lamp 2 UV LED
3 Red LED
4 phosphors (blue light-emitting phosphor and green light-emitting phosphor)
5 Transparent resin 6 Package 7 Gold wire

Claims (2)

  A white light emitting LED lamp in which an ultraviolet LED and a red LED are sealed with a transparent resin including a plurality of blue light emitting phosphors and green light emitting phosphors that are excited by ultraviolet rays to emit light.   The white light emitting LED lamp according to claim 1, wherein the plurality of blue light emitting phosphors and green light emitting phosphors are arranged in a dispersed state in the transparent resin.

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