EP2299800A1

EP2299800A1 - Led based housing

Info

Publication number: EP2299800A1
Application number: EP08761106A
Authority: EP
Inventors: Johan Behen; Bruno Cosijns; Olivier Douxchamps; Sebastien Malchaire
Original assignee: AGC Glass Europe SA
Current assignee: AGC Glass Europe SA
Priority date: 2008-06-17
Filing date: 2008-06-17
Publication date: 2011-03-30
Also published as: WO2009152848A1; CN102065679A

Abstract

Housing (100) for t he growth of photosynthetic organisms comprising at least two transparent panels (10) each of which embedding a plurality of LEDs.

Description

LED based Housing

1. Field of the invention

This invention relates to housing for the growth of photosynthetic organisms.

2. Description of related art

Photosynthetic organisms (plants, alga, bacterium, ... ) grow thanks to light. Plants require two wavelength range well defined. From wavelengths in the blue (more energetic) , plants can synthesize glucose, and from glucose and wavelengths in the red, plants can produce cells. In nature, light is provided by the sun. However, there are periods during which the light is not optimal. For example, in the morning, evening or in winter, the blue spectrum is reflected on the ozone layer and only a small portion of the spectrum reaches the earth's surface which can lead to deficiency in red color for photosynthetic organism. It can also happen that a plant needs vary from period to period. The proportion of red light over the blue light could be insufficient. The use of artificial light can supplement these deficiencies and encourage the growth of plants.

As described by the U.S. Patent Application No. US2004/0233672A1, there are greenhouses, including luminaries-based light-emitting diodes (LEDs) allowing both to provide the photosynthetic organisms present in the greenhouse an artificial light generated by LEDs and a portion of the daylight. However, in such a greenhouse, on the one hand (as indicated in the document No. US2004/0233672A1) LED luminaires block a portion of natural light (creating shadows in the greenhouse during periods with high exposure to the sun) and on the other hand, due to the fact that these luminaries are heavy, they require the use of opaque structures which also reduce the spread of sunlight toward the photosynthetic organisms present in the greenhouse.

3. Objectives of the invention

The invention, in at least one embodiment, aims to provide a housing or chamber for the growth of photosynthetic organisms which allows for a good illumination of the photosynthetic organisms thanks to natural light and thanks to artificial light.

The invention, in at least one embodiment, also aims to provide such a solution which makes it possible to compensate for spectral holes in the spectrum of natural light and more particularly to compensate for the absence of light at night.

The invention, in at least one embodiment, also aims to provide such a solution which makes it possible to obtain a uniform distribution of light provided to the photosynthetic organisms.

The invention, in at least one embodiment, also aims to provide such a solution which makes it possible to obtain an artificial light the spectrum of which is different toward different zones of the housing or toward different photosynthetic organisms in the housing.

The invention, in at least one embodiment, also aims to provide such a solution which allows to associate a plurality of light sources in the housing.

The invention, in at least one embodiment, also aims to provide such a solution which is simple and cost effective.

4. Summary of the invention

According to a first aspect, the present invention provides a housing as defined in Claim 1. The dependent claims define features of preferred or alternative embodiments of the invention.

5. Brief description of the drawings

Non-limiting embodiments of the invention are described with reference to the accompanying drawings of which:

Fig. 1 is a schematic view of a green house according to an embodiment of the invention;

Fig 2 is a plan view of a panel of the green house ;

Fig 3 is an expanded cross section;

Fig 4 is a schematic view of one form of electrical pathways interconnecting adjacent LEDs;

Fig 5 is a schematic view similar to Fig 3 with an alternative form of LEDs;

Fig 6 is a schematic view of another form of electrical pathways interconnecting adjacent LEDs.

6. Description of at least one embodiment of the invention

From EP 1 437 215, panels of laminated glass with integrated electronic components, such as light emitting diodes (LED), are known, e.g. for displaying information or for lighting purposes. For these application areas, the manufacturing of a panel of laminated glass with electronic components typically comprises the steps of depositing a conducting layer on the first layer of glass substrate, forming conductive paths and patterns in the conductive layer and depositing of electronic components on the conducting layer, connected to the conductive paths. The plastics interlayer is then deposited on the conducting layer. The sandwich is obtained by the application of the second layer of glass on the plasties interlayer, which is then laminated as outlined before.

EP 1 437 215 (the description of which is considered to be incorporated in the present description by reference) describes such a panel of laminated glass with at least two glass substrates and one or more plastic interlayers, such as PVB, in which the electronic components as well as their connecting circuits are formed between the two glass substrates, wherein the connecting circuits are formed from at least one conductive layer. Electrical power from a power source can be applied to the conductive layer of the panel of laminated glass of EP 1 437 215 via a connector as described in EP1840449A1 (the description of which is considered to be incorporated in the present description by reference).

In an embodiment of the present invention, it is proposed to manufacture a housing (or chamber) for instance, a green house 100, as illustrated by figure 1, the panels 10 of which are panels of laminated glass containing embedding uniformly distributed LEDs as described hereafter. For example, the LEDs in the panels of the green house are chosen to be SM ("Surface Mount") packaged RGB (Red, Green, Blue) LEDs manufactured by STANLEY (e.g. ref. URGB1313C- TR the dimensions of which are 1.6 mm X 1.5 mm X 0.7mm) which can be controlled such as to select the appropriate spectral light for the photosynthetic organisms (plant, biota, alga, bacterium, ... ) contained in the green house. For instance, the green house is a bio reactor which contains alga 101 (and salted water) and which is transparent in order to let natural light 102 illuminating alga and which, thanks to the uniformly distributed RGB LEDs, allow for uniform illumination of alga with spectrally selected light (e.g. for compensation of spectral holes in natural light spectrum) and for illumination of alga when natural light is reduced or absent (e.g. at night) . It is described here after panels which can be used to manufacture the green house according to an embodiment of the present invention. As illustrated by Fig. 2 glazing panel 10 comprises first 11 and second 12 flat, clear, 3mm thick soda lime float glass sheets laminated together by means of a 0.76 mm thick sheet of PVB 13. The inner surface 14 of the first glass sheet 11 is provided with a substantially colour neutral CVD coating stack 15 comprising an SiOxCy undercoat and an overlying SnO2:F coating. The coating has a resistance of about 15 ohms per square. Interruptions 16 in the coating stack 15 formed by laser ablations about 70 microns wide define electrically conducting pathways between LEDs 17 which are soldered or attached with an electrically conductive adhesive 19 either side of the laser ablations 16. Each LED is in direct contact with the coating 15 of the first glass sheet 11, the spacing shown in FIG 3 being schematic and not representative of the actual positioning. Additional laser ablations 18 divide the array of LEDs 17 in to individual lines of LEDs 101, 102, 103, etc which are connected in series. The lines of LEDs are connected to bus bars (not shown) positioned at opposite edges 121 , 122 of the glazing panel.

In this embodiment, the LEDs are adapted to provide illumination through the second glass sheet 12, i.e. without passage through or hindrance by the conductive pathways provided by the coating layer 15.

The LEDs are arranged in a regular grid at 5cm intervals such that the array of diodes covers substantially the entire area of glazing panel. Each LED has a surface area of about 4mm².

In the embodiment of Fig 4, each LED 17 is a RGB LED having three individual light emitting dies within its packaging. Each die has an associated connection or lead 21 , 22 23 arranged at the ό exterior of the packaging which is electrically connected to the its associated electrical pathway 31, 32 33.

The connection portion 35 of electrical pathway 32 has a width of the order of 1 to 2 mm and is in the form of a narrowing of the transfer portion 34 of the electrical pathway. Transfer portion 34 may have a width of the order of 20 to 60 mm.

In the embodiment of Fig 5, three individual LEDs 41, 42 and 43 are arranged together in a cluster. These may be individual red, green and blue emitting LEDs.

In the embodiment of Fig 6, the narrowing of the electrical pathway 52 from the transfer portion 54 to form the connection portion 55 is achieved progressively rather than in a step. This may facilitate current flow within the electrical pathway; it may reduce the risk of creating hot spots; it may be more convenient to manufacture.

Obviously, instead of laminating the first 11 and second 12 glass sheets together with the PVB 13, another panel according to the invention can be obtain by associating the first and second glass sheets so as to let between them a gas (air, argon, ... ) filled space like an insulating glazing.

Owing to the fact that the material of the panel is chosen transparent (e.g. glass or other transparent material such as plastic transparent materials) and due to the fact that the SM packaged LED have very small dimensions (few mm3) compared with classical LED luminaires, the green house according to the invention allow for illuminating the photosynthetic organism contained in the housing with artificial light with spectrally selected light (e.g. for compensation of spectral holes in natural light spectrum) and with natural light which is not blocked by the green house or by the light sources contained in the green house. Obviously, the invention concerns all type of housing for the growth of photosynthetic organisms (plant, biota, alga, bacterium, ... ) which can be a green house, an aquarium, a bioreactor, a vivarium, a veranda, ... or other housing which can be closed or opened. For instance, the housing can have open edges in order to cool indoor temperature by air circulation in the housing. Such an open housing can be useful for alga bioreactor applications.

Moreover the embedded LEDs can be any kind of LEDs (die, SM packaged, ... ) , any color LEDs (white, blue, red, RGB... ) and can be uniformly distributed or randomly distributed in the glass panel or can also be positioned in the glass panel such as to illuminate more particularly one or a plurality of zones of the housing or in order to illuminate a first zone of the housing with light which has a blue dominant spectrum and other part of the housing with red dominant spectrum ... At least one or each LED can be associated with an optic such as a lens in order to obtain a collimated beam directed on particular zone of the housing.

Thus, embedding LEDs in the panels of a housing according to the invention instead of using LED based luminaires in the housing can allows for a good illumination of the photosynthetic organisms thanks to artificial light but also thanks to natural light due the fact that small surface LEDs do not (or substantially do not) block artificial light (LEDs substantially do not create shadow effect in the housing) .

Due to the fact that LED light color and intensity can be precisely selected (or can be tuned thanks to well known electronic), the housing according to the invention makes it possible to compensate for spectral holes in the spectrum of natural light and more particularly to compensate for the absence of light at night. In the case where LEDs are uniformly distributed in each panel of the housing according to the invention, we obtain a uniform distribution of light provided to the photosynthetic organisms.

By choosing appropriate LEDs that are embedded in the panels (for instance red LED in one zone and blue LEDs in another zone of the panel) of the housing according to the invention, it is possible to obtain an artificial light the spectrum of which is different toward different zones of the housing or toward different photosynthetic organisms in the housing.

Due to the fact that the surface of a LED is almost negligible, it is possible to multiply the sources of light in a housing according to the invention. The LED allow for spectral selection of the light and the integration of LED in the glass helps minimizing the shadow effect created by the light source and its support. As a result, a greenhouse for growing plants or a bioreactor for the cultivation of algae (or any other housing for the growth of photosynthetic organism) according to the invention will far less suffer the adverse effects of classical artificial light sources which are a poor performance (spectrum wavelength too broad or not perfectly adapted (neon)), a significant reduction of light received during periods of sun exposure (shadow effect) and an inhomogeneous distribution of light. Moreover, in the case of classical light sources, to minimize the shadow areas, one is tempted to limit the number of light sources, this problem disappears in the case where LEDs are inserted in the glass.

Therefore, in a housing according to the invention, we can choose (or select precisely) the spectrum of light that is provided to the photosynthetic organism in order to optimize photosynthesis (spectrum is chosen according to the needs of these organisms), the shadow effect is minimal as the LED have a very small surface (and therefore create substantially no shadow effect) and as it is no more necessary (contrary to classical solutions) to use opaque structures for the binding of the light sources in the housing. Moreover, in a housing according to the invention, the LEDs (light sources) can be distributed over a wide area in the housing which can produce homogeneous light toward the photosynthetic organisms.

Claims

1. Housing (100) for the growth of photosynthetic organisms comprising at least two transparent panels (10) each of which embedding a plurality of LEDs.

2. Housing in accordance with claim 1, wherein each panel comprises :

a transparent substrate;

an electrically conductive coating layer;

a plurality of LEDs, with adjacent LEDs being electrically connected via electrical pathways defined within the electrically conductive coating layer.

3. Housing in accordance with any preceding claim, in which the electrically conductive coating layer is substantially transparent.

4. Housing in accordance with any preceding claim, in which the electrically conductive coating is deposited directly on the surface of the transparent substrate.

5. Housing in accordance with any preceding claim, in which the panel comprises a second substrate, spaced from the first substrate so that the LEDs are positioned between the two substrates.

6. Housing in accordance with claim 5, in which the first substrate and the second substrate are glass sheets, spaced each other with an intervening gas filled space.

7. Housing in accordance with claim 5, in which the first substrate and the second substrate are glass sheets and in which the two glass substrates are laminated together via plastics interlayer, preferably comprising a layer of pvb.

8. Housing in accordance with any preceding claim, in which the adjacent LEDs are RGB LEDs, the red, green, and blue dies of the adjacent LEDs being interconnected via separate electrical pathways and which are controlled in order to illuminate the photosynthetic organisms with a predetermined spectrum.

9. Housing in accordance with claim 10, in which the spectrum is chosen in order to compensate for holes in natural light spectrum.

10. Housing in accordance with any preceding claim, in which the LEDs are surface mount packaged LEDs.

11. Housing in accordance with any preceding claim, wherein the housing has at least one open edge in order to cool indoor temperature by air circulation in the housing.

12. Housing in accordance with any preceding claim, in which the housing is at least one of the following housings :

a bioreactor for the growth of alga; a green house for the growth of plants; an aquarium; a vivarium; a veranda.