MULTICOLOR LIGHT EMITTING DIODE LAMP FOR PLANT GROWTH, ILLUMINATION APPARATUS, AND PLANT GROWTH METHOD

• US 20120124903A1
• Filed: 08/05/2010
• Published: 05/24/2012
• Est. Priority Date: 08/07/2009
• Status: Active Grant

• Current Assignee: Resonac Corp. (Resonac Holdings Corp.)
• Original Assignee: Showa Denko KK
• Inventors: Takeuchi, Ryouichi
• Granted Patent: US 9,485,919 B2
• Time in Patent Office: Days
• US Class Current: 47/58.1LS
• CPC Class Codes: A01G 7/04 Electric or magnetic or acoustic treatment of plants for promoting growth
• CPC Class Codes: A01G 7/045 with electric lighting
• CPC Class Codes: F21Y 2113/10 of different colours
• CPC Class Codes: F21Y 2113/13 comprising an assembly of point-like light sources
• CPC Class Codes: F21Y 2115/10 Light-emitting diodes [LED]
• CPC Class Codes: H01L 2224/45144 Gold (Au) as principal constituent
• CPC Class Codes: H01L 2224/49175 Parallel arrangements
• CPC Class Codes: H01L 25/0753 the devices being arranged next to each other
• CPC Class Codes: H01L 2924/00 Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
• CPC Class Codes: Y02P 60/14 Measures for saving energy, e.g. in green houses

Abstract

In an illumination apparatus for plant growth using LEDs, a light source emitting mixed color light of red and blue is dominant light source. However, actually, the luminescence intensity of red light is weaker than that of blue light, and the color is adjusted by the number of lamps used. Thus, a small number of blue LEDs are interspersed among a large number of red LEDs, and there is a problem in that it is not possible to make irradiation of blue light uniform. The present invention provides a multicolor light emitting diode lamp in which a blue LED and a AlGaInP-based red LED having high luminescence efficiency, balancing with the blue LED are mounted in the same package. The red LED includes a light emitting section including a light emitting layer having a composition formula, (Al_XGa_1-X)_YIn_1-YP (0≦X≦1 and 0<Y≦1). The red LED emits at least as many photons as the blue LED when the same electric current is flowed. For example, when a strong red light is desirable for plant growth, by mounting two red LEDs and one blue LED, a desired mixed color is obtained with one lamp, and irradiation of light can be made uniform.

Claims

1. A multicolor light emitting diode lamp for plant growth comprising:

a first light emitting diode including a pn-junction type light emitting section having a light emitting layer which has a composition formula, (Al_XGa_1-X)_YIn_1-YP (0≦

X≦

0.1 and 0<

Y≦

1), and in which a peak luminescence wavelength is not less than 655 nm and not more than 675 nm; and

a second light emitting diode including a light emitting layer which has a composition formula, Ga_XIn_1-XN (0≦

X≦

1) and in which a peak luminescence wavelength is not less than 420 nm and not more than 470 nm,

wherein one or more of the first light emitting diodes and one or more of the second light emitting diodes are mounted on the same package, and

wherein a photon flux R [μ

mol·

s<sup>−

1</sup>] of the one or more of the first light emitting diodes and a photon flux B [μ

mol·

s<sup>−

1</sup>] of the one or more of the second light emitting diodes mounted on the multicolor light emitting diode lamp satisfy a relation of R>

B using the same electric current.

2. The multicolor light emitting diode lamp for plant growth according to claim 1,

wherein the number of first light emitting diodes mounted is greater than the number of second light emitting diodes mounted.

3. The multicolor light emitting diode lamp for plant growth according to claim 1,

wherein the distance between two adjacent light emitting diodes of the first and second light emitting diodes is within 10 mm.

4. An illumination apparatus for plant growth comprising:

two or more of the multicolor light emitting diode lamps for plant growth according to claim 1,

wherein the multicolor light emitting diode lamps for plant growth are disposed at approximately equal intervals and configured to be independently controllable.

5. The illumination apparatus for plant growth according to claim 4,

wherein the number of multicolor light emitting diode lamps for plant growth is controllable in accordance with a growth area of plants.

6. The illumination apparatus for plant growth according to claim 4,

wherein a photon flux of the multicolor light emitting diode lamp for plant growth is controllable in accordance with the distance between the light emitting diode lamp and plants.

7. The illumination apparatus for plant growth according to claim 4,

wherein an electric current applied to the multicolor light emitting diode lamp for plant growth is pulse-driven, and

wherein a lighting time of the multicolor light emitting diode lamp for plant growth is controllable in accordance with the growth state of the plants.

8. The illumination apparatus for plant growth according to claim 4, further comprising:

a light guide panel having a light extraction surface,

wherein light of the multicolor light emitting diode lamp for plant growth taken from a side surface of the light guide panel is extractable from the light extraction surface.

9. A plant growth method of controlling a combination of one or more of the number of multicolor light emitting diode lamps for plant growth lit, the photon flux, the applied electric current, and the pulse driving time of the illumination apparatus for plant growth according to claim 4 in accordance with the growth state of plants.