Plant illumination device and method for dark growth chambers

• US 9,883,635 B2
• Filed: 09/28/2016
• Issued: 02/06/2018
• Est. Priority Date: 03/17/2011
• Status: Active Grant

• Current Assignee: Valoya Oy
• Original Assignee: Valoya Oy
• Inventors: Aikala, Lars, Kivimaki, Ilkka
• Primary Examiner(s): RALEIGH, DONALD L
• Application Number:
  US15/278,227
• Publication Number:
  US 20170013786A1
• Time in Patent Office: 496 Days
• CPC Class Codes: A01G 7/045 with electric lighting
• CPC Class Codes: F21K 9/64 using wavelength conversion means distinct or spaced from the light-generating element, e.g. a remote phosphor layer
• CPC Class Codes: F21V 15/01 Housings, e.g. material or assembling of housing parts F21V15/02 takes precedence housings forming signs or letters G09F13/04
• CPC Class Codes: F21V 9/30 Elements containing photoluminescent material distinct from or spaced from the light source shades F21V1/17; globes, bowls or cover glasses F21V3/08, F21V3/12; refractors F21V5/10; reflectors F21V7/26, F21V7/30; elements with provision for controlling the spectral properties or intensity F21V9/40
• CPC Class Codes: F21V 9/40 with provision for controlling spectral properties, e.g. colour, or intensity
• 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 2933/0083 Periodic patterns for optical field-shaping in or on the semiconductor body or semiconductor body package, e.g. photonic bandgap structures
• CPC Class Codes: H01L 33/06 within the light emitting region, e.g. quantum confinement structure or tunnel barrier
• CPC Class Codes: H01L 33/504 Elements with two or more wavelength conversion materials
• CPC Class Codes: Y02P 60/14 Measures for saving energy, e.g. in green houses

Abstract

An improved method to produce artificial light for plant cultivation, an illumination device with a semiconductor light emission solution and device suited for plant cultivation in a greenhouse and/or dark growth chamber environment are described. The best mode is considered to be a lighting device with LEDs that produces an emission spectrum similar to the photosynthetically active radiation (PAR) spectrum in a dark growth chamber. The methods and arrangements allow more precise spectral tuning of the emission spectrum for lights used in plant (310, 311) cultivation. Therefore unexpected improvements in the photomorphogenetic control of plant growth, and further improvements in plant production, especially in dark growth chambers, such as basements, are realized.

Claims

1. A lighting system, comprising:

a housing defining a dark cavity with zero sunlight therein; and

at least one horticultural lighting fixture comprising

a) a first emission source comprising at least one light emitting diode (LED) and/or quantum dot emitting main spectral characteristics in the photosynthetically active radiation (PAR) (400-700 nm) area, the main spectral characteristics comprising at least two spectral peaks with non-zero emission intensity, and

b) a second emission source comprising at least one light emitting diode (LED) and/or quantum dot emitting at least one side spectral characteristics selected from first spectral characteristics in the 700-800 nm area, and second spectral characteristics in the 300-400 nm area, the at least one side spectral characteristics comprising at least one spectral peak with non-zero emission intensity,

wherein emission intensities of the first emission source and the second emission source are independently controllable.

2. The lighting system according to claim 1, wherein the main spectral characteristics comprise at least one peak coinciding with an absorption peak of photoreceptors of a plant.

3. The lighting system according to claim 2, wherein the main spectral characteristics comprise at least two peaks matching carotenoid and chlorophyll absorption peaks of a plant.

4. The lighting system according to claim 2, wherein the main spectral characteristics have

a) first spectral characteristics including a peak in the wavelength range from 600 to 700 nm and arranged to exhibit a full width of half maximum of at least 50 nm or more, and

b) second spectral characteristics with a maximum of 50 nm full width of half maximum and arranged to exhibit a peak wavelength in the range from 440 to 500 nm.

5. The lighting system according to claim 4, wherein at least a part or the whole of the emission of the main spectrum at wavelengths of 500-600 nm is minimized and/or omitted and/or to be reduced below the intensity in 400-500 nm band and below the intensity in 600-700 nm band.

6. The lighting system according to claim 1, wherein the side spectral characteristics comprise a peak in the far-red wavelength region.

7. The lighting system according to claim 1, wherein at least part of the emission by the LED or the quantum dot at a frequency of 600-800 nm is generated using wavelength up-conversion.