LIGHT EMITTING DEVICE, LED LIGHT SOURCE FOR PLANT CULTIVATION, AND PLANT FACTORY

• US 20130264934A1
• Filed: 11/15/2011
• Published: 10/10/2013
• Est. Priority Date: 11/25/2010
• Status: Active Grant

• Current Assignee: Sharp Kabushiki Kaisha (Hon Hai Precision Industry Co., Ltd.)
• Original Assignee: Sharp Kabushiki Kaisha (Hon Hai Precision Industry Co., Ltd.)
• Inventors: Osaki, Shinji, Uemura, Toyonori, Hata, Toshio, Nada, Tomokazu, Morioka, Tatsuya, Matsuda, Makoto, Ishizaki, Shinya, Agatani, Makoto, Matsushita, Hitoshi
• Granted Patent: US 9,666,769 B2
• Time in Patent Office: Days
• US Class Current: 313/46
• CPC Class Codes: A01G 7/045 with electric lighting
• CPC Class Codes: H01L 2224/48091 Arched
• CPC Class Codes: H01L 2224/48247 connecting the wire to a bond pad of the item
• CPC Class Codes: H01L 2224/48257 connecting the wire to a die pad of the item
• 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: H01L 2924/00014 the subject-matter covered by the group, the symbol of which is combined with the symbol of this group, being disclosed without further technical details
• CPC Class Codes: H01L 33/502 Wavelength conversion materials
• CPC Class Codes: H01L 33/504 Elements with two or more wavelength conversion materials
• CPC Class Codes: H05B 33/12 Light sources with substantially two-dimensional radiating surfaces
• CPC Class Codes: Y02P 60/14 Measures for saving energy, e.g. in green houses

Abstract

A substrate-type LED light source (10) includes: at least one blue LED chip (2) which has an emission peak in a range from 400 nm to 480 nm so as to correspond to a blue light region absorption peak of chlorophyll; a red phosphor (7b) which emit, upon receiving excitation light from the at least one blue LED chip (2), light having a peak wavelength in a range from 620 nm to 700 nm so as to correspond to a red light region absorption peak of chlorophyll; and a resin layer (7) in which the red phosphor 7b is dispersed and which covers the at least one blue LED chip (2).

Claims

1. A light emitting device, comprising:

at least one first LED chip which emits first short-wavelength-region light corresponding to a first peak wavelength, which is in a relatively short wavelength region, of a plurality of peak wavelengths of light absorbed by a plant or an alga which requires the light for photosynthesis to grow; and

a phosphor-containing sealing resin which covers said at least one first LED chip,

a phosphor contained in the phosphor-containing sealing resin emitting long-wavelength-region light upon absorbing the first short-wavelength-region light emitted from said at least one first LED chip, the long-wavelength-region light corresponding to a peak wavelength, which is in a longer wavelength region than the first peak wavelength, of the plurality of peak wavelengths.

2. A light emitting device according to claim 1, further comprising at least one second LED chip which emits second short-wavelength-region light corresponding to a second peak wavelength, which is in the relatively short wavelength region but is a different wavelength from the first peak wavelength, of the plurality of peak wavelengths.

3. An LED light source for plant cultivation, including a light emitting device recited in claim 1, comprising:

at least one blue LED chip having an emission peak in a range from 400 nm to 480 nm so as to correspond to a blue light region absorption peak of chlorophyll;

a red phosphor which emits, upon receiving excitation light from said at least one blue LED chip, light having a peak wavelength in a range from 620 nm to 700 nm so as to correspond to a red light region absorption peak of chlorophyll; and

a resin layer in which the red phosphor is dispersed and which covers said at least one blue LED chip.

4. The LED light source for plant cultivation according to claim 3, wherein said at least one blue LED chip is constituted by:

at least one blue LED chip for chlorophyll a which blue LED chip has an emission peak in a range from 400 nm to 450 nm so as to correspond to a blue light region absorption peak of the chlorophyll a; and

at least one blue LED chip for chlorophyll b which blue LED chip has an emission peak in a range from 400 nm to 480 nm so as to correspond to a blue light region absorption peak of the chlorophyll b.

5. The LED light source for plant cultivation according to claim 3, wherein a ratio of a photosynthetic photon flux in a red light region of 620 nm to 700 nm to a photosynthetic photon flux in a blue light region of 400 nm to 480 nm falls within a range from 1.3:

1 to 10;

1.

6. The LED light source for plant cultivation according to claim 3, wherein a blending ratio of the red phosphor in the resin layer to a resin in the resin layer falls within a range from 0.05:

1 to 0.20;

1.

7. The LED light source for plant cultivation according to claim 3, wherein, in a case where the LED light source is to be provided to a germination shelf or a nursery shelf, a blending ratio of the red phosphor in the resin layer to a resin in the resin layer falls within a range from 0.05:

1 to 0.10;

1.

8. The LED light source for plant cultivation according to claim 3, wherein, in a case where the LED light source is to be provided to a maturation shelf, a blending ratio of the red phosphor in the resin layer to a resin in the resin layer falls within a range from 0.15:

1 to 0.20;

1.

9. The LED light source for plant cultivation according to claim 3, wherein, in a case where the LED light source is to be provided to a germination shelf or a nursery shelf, a ratio of a photosynthetic photon flux in a red light region of 620 nm to 700 nm to a photosynthetic photon flux in a blue light region of 400 nm to 480 nm falls within a range from 1.3:

1 to 3.5;

1.

10. The LED light source for plant cultivation according to claim 3, wherein, in a case where the LED light source is to be provided to a maturation shelf, a ratio of a photosynthetic photon flux in a red light region of 620 nm to 700 nm to a photosynthetic photon flux in a blue light region of 400 nm to 480 nm falls within a range from 7.5:

1;

to 10;

1.

11. The LED light source for plant cultivation according to claim 3, wherein, for cultivation of a plant containing more chlorophyll a than chlorophyll b, the red phosphor contains a CaAlSiN₃:

Eu component.

12. The LED light source for plant cultivation according to claim 3, wherein, for cultivation of a plant containing more chlorophyll b than chlorophyll a, the red phosphor contains a (Sr,Ca)AlSiN₃:

Eu component.

13. The LED light source for plant cultivation according to claim 3, wherein:

a plurality of blue LED chips are provided on a substrate, and a standing wall is provided around the plurality of blue LED chips; and

a space inside the standing wall is filled with a resin in which the red phosphor is dispersed.

14. An LED light source for plant cultivation according to claim 3, comprising:

a cathode lead;

a cup connected with the cathode lead;

said at least one blue LED chip provided in the cup;

an anode lead connected, via a conductive wire, with said at least one blue LED which is provided in the cup;

a resin layer in which the red phosphor is dispersed and with which the cup is filled so that said at least one blue LED chip is covered; and

a sealing resin which has a bullet shape and encloses the entire cup such that an end of the cathode lead and an end of the anode lead are exposed.

15. The LED light source for plant cultivation according to claim 3, which emits first light having a wavelength of 400 nm to 480 nm and second light having a wavelength of 620 nm to 700 nm.

16. The LED light source for plant cultivation according to claim 3, which emits (i) first light from said at least one blue LED chip and (ii) second light that the red phosphor emits upon excitation by said at least one blue LED chip.

17. The LED light source for plant cultivation according to claim 13, wherein cooling means is provided on a back surface of the substrate.

18. A plant factory, comprising:

a first and second LED light source for plant cultivation, each of the first and second LED light source comprising;

at least one first LED chip which emits first short-wavelength-region light corresponding to a first peak wavelength, which is in a relatively short wavelength region, of a plurality of peak wavelengths of light absorbed by a plant or an alga which requires the light for photosynthesis to grow; and

a phosphor-containing sealing resin which covers said at least one first LED chip,

a phosphor contained in the phosphor-containing sealing resin emitting long-wavelength-region light upon absorbing the first short-wavelength-region light emitted from said at least one first LED chip, the long-wavelength-region light corresponding to a peak wavelength, which is in a longer wavelength region than the first peak wavelength, of the plurality of peak wavelengths;

at least one blue LED chip having an emission peak in a range from 400 nm to 480 nm so as to correspond to a blue light region absorption peak of chlorophyll;

a red phosphor which emits, upon receiving excitation light from said at least one blue LED chip, light having a peak wavelength in a range from 620 nm to 700 nm so as to correspond to a red light region absorption peak of chlorophyll; and

a resin layer in which the red phosphor is dispersed and which covers said at least one blue LED chip

wherein, for the first LED light source in a case where the first LED light source is to be provided to a germination shelf or a nursery shelf, a ratio of a photosynthetic photon flux in a red light region of 620 nm to 700 nm to a photosynthetic photon flux in a blue light region of 400 nm to 480 nm falls within a range from 1.3;

1 to 3.5;

1; and

wherein, for the second LED light source in a case where the second LED light source is to be provided to a maturation shelf, a ratio of a photosynthetic photon flux in a red light of 620 nm to 700 nm to a photosynthetic photon flux in a blue light region of 400 nm to 480 nm falls within a range from 7.5;

1 to 10;

1.