DE3214550A1 - FLUORESCENT LAMP FOR EXCITING A BALANCED PLANT GROWTH - Google Patents

Description

32H550

Patent Trust Company

for electric light bulbs mbH., Munich

Fluorescent lamp to stimulate balanced plant growth *)

The invention relates to a fluorescent lamp for stimulating balanced plant growth in which the phosphor mixture applied to the inner wall of the lamp vessel contains three components, with as first component a manganese-activated magnesium fluorogermanate with an emission maximum at 660 nm and as second component a tin-activated strontium magnesium orthophosphate with an emission maximum at 626 nm is used.

For fluorescent lamps for the purpose of plant, flower and ornamental fish irradiation, various phosphor mixtures have been proposed so far, the emission of which is matched to the different absorption of the plants at the individual wavelengths, in particular the visible spectral range. In practice, this phosphor mixtures are often used which have about 55 wt -% composed of a calcium tungstate and ^ 5 wt .-% of an activated with manganese magnesium fluorogermanate.. Magnesium fluorogermanate, however, is very expensive, which is why other phosphor mixtures without or with a significantly reduced proportion of this expensive component have long been sought without the spectral emission properties of the fluorescent lamp being adversely affected. For example, it is known from US Pat. No. 4,055,781 that the proportion of magnesium fluorogermanate phosphor with its dark red emission is preferably 10% by weight to 30% by weight

*) H 01 J

20% by weight. To preserve the energies in However, it became necessary to use the phosphor mixture in addition to the spectral ranges that are essential for the plant the magnesium fluorogermanate three other phosphor components with different emission properties to add. Admittedly, with the help of these measures the material price of the phosphor mixture used reduced to a third of the original price, but it is necessary to achieve a defined color location the mixture consisting of a total of four phosphors ensures that all manufacturing tolerances are met exactly necessary. The reason is that one consists of four phosphor components Mixing is not a sufficient criterion for determining the color location. The color location setting is true this is possible due to different mixing ratios, but then the radiation properties are shifted the lamp.

Another disadvantage of the calcium tungstate and magnesium fluorogermanate used in practice Phosphor mixture lies in the need to fill the lamp bulb with a one To have to make suspension containing organic binders. Dilute solutions of a high viscosity nitrocellulose in butyl acetate used. Except for one when processing with these organic ones Binder prepared phosphor suspensions occurring Odor nuisance is also the effort to prevent environmental damage with such solvents quite considerable.

The object of the invention is to create a phosphor mixture suitable for plant irradiation, which cheap to manufacture and easy to process

and for the environmentally friendly, inexpensive water sludge can be applied. The essential characteristic for the plant physiological In addition, the effect of wavelength ranges should be as close as possible to that of natural sunlight will.

The fluorescent lamp for stimulating balanced plant growth with the features mentioned in the preamble of the main claim is characterized according to the invention in that the third component is a barium magnesium aluminate activated with divalent europium with an emission maximum at kk "? Nm. Fluorogermanate is only 10 to 25% by weight, preferably 20% by weight, of the total weight of the phosphor mixture. With more than 25% by weight the price advantage would no longer be sufficiently attractive, while with less than 10% by weight. The cheap, tin-activated strontium magnesium orthophosphate is 55 to 80% by weight, preferably 65% by weight, and the barium magnesium aluminate activated with divalent europium is with 10 to 20% by weight, preferably 15% by weight, of the total weight of the phosphor mixture.

The phosphor mixture according to the invention is approx.

two thirds cheaper than the previously used mixture.

The new phosphor mixture is also easy to manufacture and for processing in a mass production well suited. By using only three components, the target color location is unique Criterion for the phosphor composition. The standard color value component the preferred mixture is 0.339 for χ and 0.247 for y; the lamp thus emits

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in a purple color that is common in plant lighting Color that makes plants and ornamental fish look particularly attractive, but the color location is up approx. 30 SWE (threshold units) towards the Achromatic point shifted. This makes it possible to use such a fluorescent lamp as room lighting Use greenhouses and corresponding sales rooms.

The transition from the previous one is due to the fact that only a small proportion of the germanate component is still used used phosphor suspension with organic Binder on the cheaper, environmentally friendly water sludge possible. With the new phosphor and simultaneous use of lamp bulbs with a bulb diameter reduced to 26 mm can be used with an additional approx. 10% of the electrical energy costs with an approximately doubled luminous flux. Also be With the material savings associated with this, the final costs for the fluorescent material are about a quarter of the origin reduced costs.

The invention is explained in more detail below with reference to the figures:

Figure la shows the relative spectral action function

s (X) ₁ of photosynthesis.

Figure Ib shows the relative spectral action function s (Λ) _h -, the chlorophyll synthesis.

Figure Ic shows the relative spectral action function

s () \). _Ί of phototropism, xr, rei

Figure Id shows the relative spectral action function s (^ j) _ of photomorphogenesis.

ΙΩΟ f Γ β JL *

Figure 2 shows the emission spectrum of a fluorescent lamp with a conventional phosphor mixture was humiliated.

FIG. 3 shows the emission spectrum of a fluorescent lamp with the fluorescent mixture according to the invention was humiliated.

In the figures la to Id are according to DIN 5031 different courses of the plant-physiological effect functions are shown. Photosynthesis (Fig. 1a) and the chlorophyll synthesis (Fig. Ib) each show maxima at 445 nm and 660 nm. The phototropism (Fig. Ic) shows a broad curve with maxima at 440 nm and 470 nm and the photomorphogenesis (Fig. Id) shows a narrow induction maximum (curve A) at 66O nm and a somewhat broader reversion maximum (Curve B) at approx. 730 nm. In the green spectral range (510 nm to 610 nm) the plants show only a smaller one photosynthetic effectiveness and weak morphogenetic activity. Radiation of the wavelengths above 1000 nm, if the plant absorbs them at all, there will be no disturbance of the biochemical processes converted into heat by the plant. A fluorescent lamp used for plant irradiation should with their total emission therefore also have a maximum at least in the maxima of the plant physiological reaction curves given above. When growing plants But it has also been shown that certain plants not only with the radiation components in the Ranges from approx. 400 nm to approx. 500 nm (blue) and approx. 600 nm to approx. 700 nm (red) flourish, but above that In addition, there is also a certain amount of daylight, especially its green-yellow portion of radiation in the area approx. 550 nm to 580 nm for the synthesis of enzymes and

- 7 and other fabrics.

In Figures 2 and 3, the respective emission spectrum is one with a conventional one and one according to the invention Fluorescent mixture coated fluorescent lamp shown comparatively. The emission spectrum FIG. 2 comes from a 40 W fluorescent lamp with a bulb diameter of 38 mm, approx. 55% by weight of the phosphor mixture consisting of the blue emitting

j [O tier forming calcium tungstate, and about 45 wt -% consists of the expensive, red-emitting, activated with manganese magnesium fluorogermanate.. The phosphor mixture is dissolved in a dilute solution of a highly viscous nitrocellulose in butyl acetate. After the elutriation has taken place, the lamp bulb is baked out in a bake-out furnace, the organic constituents of the suspension volatilizing.

The emission spectrum in FIG. 3 comes from a 36 W fluorescent lamp with a bulb diameter of 26 mm. According to the invention, the phosphor mixture contains only 20% by weight of the expensive, red-emitting, manganese-activated magnesium fluorogermanate. The resulting lack of red in the mixture was filled by adding 65% by weight of the much cheaper, red-orange emitting tin-activated strontium-magnesium-orthophosphate phosphor. The fluorescent lamp receives the required blue component by adding 15% by weight of a barium magnesium aluminate phosphor activated with divalent europium to the phosphor mixture. In addition to an optimization in the blue area, the spectrum also shows the balance of blue and red emissions. Likewise could - compared to the spectrum of a conventional fluorescent lamp of green-yellow radiation component (550 nm - 58Ο nm) German

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borrowed to be raised. This is in addition to a promotion the synthesis of enzymes also simultaneously shifts the color point towards the achromatic point causes, which in turn improves the color rendering and the use of the radiation lamps as well in greenhouses and their sales rooms. The standard color table results from the emission spectrum according to DIN 5033 a color point with the standard color value proportions χ = 0.339 and y = 0.247. The one with the

IQ inventive Leuchtstoffmxschung coated fluorescent lamp is manufactured in a known manner as conventional fluorescent lamps, the phosphor blend but was instead dissolved in an organic solvent in the much more environmentally friendly water.

As Table 1 below shows, the radiation components standardized for the chlorophyll synthesis are those according to the invention Phosphor mixture compared to a mixture used in previous practice a calcium tungstate and a magnesium fluorogermanate activated with manganese are significantly cheaper, if sunlight is used as a source of supply. In particular, the value of the metamorphosis at 730 mn tripled compared to the previously used fluorescent lamps for plant irradiation and thus sunlight can be much more approximated. The higher value of photosynthesis also causes an increased Biomass production.

Table 1: Relative radiation components

sunlight Fluorescent mixture according to Action functions 1.5 conventional 1.8 Photo synthe s e 1.0 1.5 1.0 Chlorophyll syntheses 1.2 1.0 0.6 Phototropism 0.7 0.4 0.8 Photomorphogenesis 660 mn 0.6 0.9 0.2 Photomorphogenesis 730 nm o, o6

Table 2 shows the percentage of the electrical power consumed by the lamp on the individual radiation components available for the plant are omitted.

Table 2: Availability of the electrical energy used

nm Fluorescent lamp ° / o according to the invention Action functions nm conventional ° / o 15 % photosynthesis 11th % 8 % Chlorophyll synthesis e 8th % 5% Phototropism 3 % 6 % Photomorphogenesis 66O 6th 2 % Photomorphogenesis 730 0.5

Claims (3)

32H550 Claims /!..^ Fluorescent lamp to stimulate balanced plant growth, in which the phosphor mixture applied to the inner wall of the lamp bulb contains three components, the first component being a manganese-activated magnesium fluorogermanate with an emission maximum at 66O nm and the second component being a tin-activated strontium-magnesium Orthophosphate with an emission maximum at 626 nm is used, characterized in that the third component is a barium magnesium aluminate activated with divalent europium with an emission maximum at kh.7 nm. 2. Fluorescent lamp according to claim 1, characterized in that the magnesium fluorogermanate with 10 to 25% by weight, the strontium magnesium orthophosphate with 55 to 80% by weight and the barium magnesium aluminate with 10 to 20% by weight of the total amount of the phosphor mixture. 20th 3. Fluorescent lamp according to claim 1 and 2, characterized in that that the magnesium fluorogermanate with 20 wt .-%, the strontium magnesium orthophosphate with 65 wt .-% and the barium magnesium aluminate with 15 wt .-% of the total amount of the phosphor mixture is included.