JP2001076679A - Fluorescent lamp for rearing plant - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a fluorescent lamp for rearing plants which does not hinder them from sprouting. SOLUTION: This fluorescent lamp for rearing plants is made by forming a luminescent layer 3 on an inner surface of a glass tube 2. The luminous layer is formed of a phosphor mixture, made by mixing a first phosphor 4 emitting light in a blue color range and a second phosphor 5 made up of one or more kinds emitting light in a red color range with the light emission suppressed in the range of about 650 to 700 nm. The mixing ratio of the first and second phosphors in the phosphor mixture is set, so that the ratio of the second phosphor 5 falls within the range of 0.5 to 4 by weight to the first phosphor 1.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fluorescent lamp for growing plants, and more particularly to an improvement of a fluorescent lamp for growing plants suitable for growing leafy vegetables.

[0002]

2. Description of the Related Art Conventionally, daylight fluorescent lamps have been conventionally used as a light source for growing plants indoors. However, recently, due to insufficient plant growing effects, blue light and red light have recently been used. A two-wavelength light-emitting type plant-growing fluorescent lamp utilizing light emission in a region has been developed and widely used.

[0003] In this plant growing fluorescent lamp, for example, a light emitting layer is formed on the inner surface of a glass tube, and the light emitting layer is formed of a first phosphor emitting light in a blue region and a second phosphor emitting light in a red region. And a mixture of phosphors. This fluorescent lamp for growing plants is used not only for growing plants but also as an ornamental fluorescent lamp for illuminating houseplants such as tropical plants and flowers.

[0004] More specifically, the first phosphor constituting the light emitting layer of the fluorescent lamp for growing plants is, for example, 460 nm.
A tin-activated strontium phosphate phosphor [Sr2P207: Sn] having a light emission peak at the manganese-activated magnesium fluorinated magnesium germanate phosphor having a light emission peak at 658 nm [3.5MgO · 0.5
MgF 2 .GeO 2: Mn], a europium-activated yttrium oxide phosphor having an emission peak at 611 nm [Y
2O3: Eu], europium-activated yttrium phosphanavanadate phosphor having an emission peak at 620 nm [Y
(PV) O4: Eu].

As shown in FIG. 3, the spectral energy distribution characteristic of the thus-configured plant growing fluorescent lamp is such that the spectral energy is mainly distributed in the blue region B and the red region R. Therefore, when a plant is illuminated with a plant growing fluorescent lamp having such spectral energy distribution characteristics, light in the red region mainly promotes the first growing period (the time when the leaves are enlarged) of the plant, and light in the blue region is generated. It promotes the second growth period (the time of growing leaves and thickening stalks) mainly of plants to promote overall plant growth and proves to be effective in growing leafy vegetables such as lettuce. Have been.

The above-mentioned first and second phosphors are relatively expensive, and in particular, the manganese-activated magnesium fluorogermanate phosphor of the second phosphor is remarkably expensive. Therefore, a fluorescent lamp for growing plants produced using such a phosphor is considerably more expensive than the above-described daylight fluorescent lamp, and there is a demand for cost reduction.

On the other hand, a three-wavelength emission type fluorescent lamp for ornamental / plant cultivation utilizing emission in the blue, green and red regions has been developed and put into practical use. The light emitting layer of the ornamental / plant growing fluorescent lamp includes, for example, a first phosphor that emits light in a blue region and a third phosphor that emits light in a green region.
A second phosphor that emits light in the red region,
It is composed of a mixture obtained by appropriately mixing an extender made of a non-luminescent substance.

[0008] Specifically, as the first phosphor, for example, a europium-activated strontium calcium chlorophosphate phosphor having an emission peak at 453 nm [(Sr
CaBa) 5 (PO4) 3Cl: Eu] is the third phosphor, for example, a cerium / terbium-activated lanthanum phosphate phosphor [LaP] having an emission peak at 544 nm.
O4: Ce, Tb] as the second phosphor, for example, a europium-activated yttrium oxide phosphor and a manganese-activated magnesium fluorogermanate phosphor, and as the non-emission extender, for example, yttrium oxide [Y2O3] ] Are used respectively.

The light emitting layer is formed of, for example, a mixture in which the first, second, and third phosphors are mixed at a ratio of 60% by weight and an extender at a ratio of 40% by weight. According to this ornamental / plant growing fluorescent lamp, a part of the light emitting layer is replaced by an inexpensive bulking agent, and the ratio of the first, second, and third phosphors in the light emitting layer is relatively small. Therefore, cost can be reduced. In this ornamental / plant cultivating fluorescent lamp, as shown in FIG. 4, spectral energy is mainly distributed in a blue region B, a green region G and a red region R. Therefore, when the plant is illuminated by the plant growing fluorescent lamp having such a spectral energy distribution characteristic, the plant growing effect can be obtained in the same manner as the above-described two-wavelength emission type plant growing fluorescent lamp, and in addition to the ornamental plant, The green component becomes clear and the commercial value as an ornamental fluorescent lamp is improved.

[0010]

According to the above-described two-wavelength light-emitting type and three-wavelength light-emitting type plant-growing fluorescent lamps, although an effect can be seen in growing plants such as leafy vegetables,
When a plant is grown from seed, there is a problem that the germination of the seed is delayed, so that the growth of the plant is slower than that of a plant grown from a seedling state.

[0011] As a result of exploring this point, the present inventors have found through experiments that emission energy of approximately 650 to 700 nm in the red region suppresses seed germination. In particular, the manganese-activated magnesium fluorogermanate phosphor described above has an emission peak at 658 nm, so that seed germination is suppressed.

Therefore, it is important to reduce the luminous energy in the range of about 650 nm to 700 nm in order to effectively promote the comprehensive growth of plants, and such a fluorescent lamp for growing plants is required. I have.

Therefore, an object of the present invention is to provide a fluorescent lamp for growing plants which does not suppress the germination of seeds by reducing the emission energy of approximately 650 to 700 nm in the red region.

[0014]

SUMMARY OF THE INVENTION Accordingly, in order to achieve the above-mentioned object, the present invention provides a fluorescent lamp for growing a plant in which a light emitting layer is formed on the inner surface of a glass tube, wherein the light emitting layer is formed in a blue region. A mixed phosphor in which a first phosphor that emits light and a second phosphor that is one or two or more types that emits light in a red region and suppresses light emission in a region of approximately 650 to 700 nm are mixed. And the mixing ratio of the first and second phosphors in the mixed phosphor in a weight ratio,
The second phosphor is set in the range of 0.5 to 4 with respect to the first phosphor 1.

[0015]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A fluorescent lamp 1 for growing plants shown in FIG. 1 has a two-wavelength light emitting layer 3 on the inner surface of a glass tube 2.
Are formed. The light-emitting layer 3 includes a first phosphor 4 that emits light in a blue region and a second phosphor of one or more types that emits light in a red region and suppresses light emission in a region of approximately 650 to 700 nm. Of the first and second phosphors 4 and 5 in the mixed phosphor in a weight ratio,
The second phosphor is set in the range of 0.5 to 4 with respect to the first phosphor 1.

Specifically, for example, a europium-activated strontium calcium chlorophosphate phosphor is used as the first phosphor 4, and a europium-activated yttrium oxide phosphor is used as the second phosphor 5, for example. The mixing ratio of the second phosphor to the first phosphor 1 is set in the range of 0.5 to 4.

The fluorescent lamp 1 for growing plants has a spectral energy distribution characteristic shown in FIG. As is clear from the figures, compared to the spectral energy distribution characteristics of the conventional fluorescent lamp for growing plants shown in FIGS. 3 and 4, the emission energy in the range of approximately 650 nm to 700 nm in the red region is sufficiently suppressed. Is admitted. Experiments described below have demonstrated that the germination of seeds is hardly suppressed based on the significant reduction in luminescence energy in this range.
Moreover, as can be seen from the emission energy distribution in FIG. 2, the emission energy in the blue region effective for plant growth and the red region excluding the range of approximately 650 to 700 nm is similar to that of the plant growth fluorescent lamp in FIGS. It is sufficient and functions effectively for plant growth.

In addition, the manganese-activated magnesium fluorogermanate phosphor, which emits light in the range of 658 nm, is removed from the light-emitting layer 3 so that almost 650 to 7 in the red region can be obtained.
Since the emission energy in the range of 00 nm can be effectively suppressed, not only can the germination of seeds be promoted, but also the cost can be further reduced.

As described above, the mixing ratio of the second phosphor to the first phosphor 1 is set in the range of 0.5 to 4, and within this range, a good plant growing effect can be obtained. However, outside this range, even if the germination of the plant is not suppressed, the effect of growing the plant after germination will be impaired. That is, when the mixing ratio of the second phosphor to the first phosphor 1 is less than 0.5 by weight, the emission energy in the red region outside the range of 650 to 700 nm is also reduced. The effect of growing leaves such as vegetables is insufficient. Conversely, when the weight ratio of the second phosphor to the first phosphor 1 exceeds 4, the germination of seeds is suppressed. Therefore, as the fluorescent lamp for growing plants, the mixing ratio of the first phosphor and the second phosphor must be set in the above range.

In practice, the mixing ratio between the first phosphor 4 and the second phosphor 5 is 1: 1 by weight, which is most suitable for growing a plant. Effective, 1
Up to 4 is the practical range for plant growth. Such a plant growing effect is demonstrated by comparative experimental data shown in Table 1.

[0021]

[Table 1]

In Table 1, the fluorescent lamps used in the experiments were: daylight white standard product La, conventional products Lb-1, Lb-2, reference products Lc-B, Lc-R, present products Ld-1, Ld. -2
It is. The day white reference product La is a general day white fluorescent lamp, and the plant growing state of another fluorescent lamp is evaluated later based on the plant growing state. Conventional product Lb-1 is a plant growing fluorescent lamp having the spectral energy distribution characteristic of FIG. 3, and Lb-2 is a plant growing fluorescent lamp having the spectral energy distribution characteristic of FIG. Reference product Lc-B
Lc-R is a fluorescent lamp in which a light emitting layer is formed only by a second phosphor which emits light in a red region, and Lc-R is a fluorescent lamp in which a light emitting layer is formed only by a first phosphor which emits light in a blue region. . Further, the invention prototype Ld-1 is a plant growing fluorescent lamp of the present invention in which the mixing ratio of the first phosphor and the second phosphor is set to 1 to 1 by weight, and Ld-2 is the second lamp. 1
The fluorescent lamp for growing plants according to the present invention, wherein the mixing ratio of the phosphor and the second phosphor is set to 1: 3 by weight.

The subjects of the experiment shown in Table 1 are the same leafy vegetables. The vegetable weight on the ground 41 days after germination, the number of open leaves, the vertical and horizontal dimensions of the largest open leaves, and the underground The total length of the extending root and the weight of the root were measured. Based on the reference product La as a reference, when the growth status of plants with other fluorescent lamps was evaluated,
The following results were obtained.

(1) The conventional product Lb-1 has a slower growth through the seedling stage, the young seedling stage and the growing and harvesting period than the reference product La,
In particular, the growth of the harvest season is delayed. It is considered that the delay of the seedling stage is affected by suppression of germination.

(2) Conventional product Lb-2 is also conventional product Lb-1
Almost the same as above, with suppression of germination. In addition, the leaves tend to be slightly smaller as a whole and the leaf meat is thinner.

(3) The reference product Lc-B is good in both leaf mesophyll and leaf shape in terms of luminescence energy in the blue region, but has an average inferior growth speed due to insufficient luminescence in the red region.

(4) In the reference product Lc-R, the growth speed is improved by the luminous energy in the red region, and the size and weight of the leaves and stems are increased. A falling phenomenon is observed, and the leaf shape becomes elongated.

(5) The invention prototype Ld-1 has almost no suppression of germination and grows rapidly through the seedling stage, the young seedling stage and the growing and harvesting stage, and the leaf size and weight increase. Also, the leaf shape is slightly elongated, but the leaf is good.

(6) The invention prototype Ld-2 is almost the same as the invention prototype Ld-1, and the root growth is somewhat faster. Further, the leaf shape becomes longer and thin, but the leaf meat is good and there is no problem.

It should be noted that the present invention is not limited to the above-described embodiment, and any first phosphor may be used as long as it emits light in the blue region. The second phosphor may be any phosphor that emits light in the red region and suppresses light emission at approximately 650 to 700 nm. In addition, each phosphor may be used alone, or two or more phosphors may be mixed.

[0031]

As described above, according to the present invention, the light emitting layer sets the first and second phosphors that emit light in the blue region and the red region in the range of 1: 0.5 to 4. Almost 650 which is considered to suppress germination of plants because of its composition
An emission energy in the range of -700 nm can be effectively suppressed, and an excellent plant growing function having almost no adverse effect on germination can be obtained. Moreover, since the light emitting region of the light emitting layer is limited, the cost can be reduced.

[Brief description of the drawings]

FIG. 1 is a sectional view including a partially enlarged view of a glass tube showing an embodiment of the present invention.

FIG. 2 is a spectral energy distribution diagram of the plant growing fluorescent lamp of FIG.

FIG. 3 is a spectral energy distribution diagram of a conventional fluorescent lamp for growing plants.

FIG. 4 is a spectral energy distribution diagram of a conventional ornamental / plant growing fluorescent lamp.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Fluorescent lamp for growing plants 2 Glass tube 3 Light emitting layer 4 First phosphor 5 Second phosphor

Claims (1)

[Claims] 1. A fluorescent lamp for growing a plant having a light-emitting layer formed on an inner surface of a glass tube, wherein the light-emitting layer comprises a first phosphor that emits light in a blue region, and a light-emitting member that emits light in a red region. It is formed of a mixed phosphor mixed with one or two or more kinds of second phosphors whose emission in the region of 650 to 700 nm is suppressed, and the first and second phosphors in the mixed phosphor are mixed. A fluorescent lamp for growing plants, wherein the mixing ratio of the second phosphor to the first phosphor 1 is set in the range of 0.5 to 4 in terms of weight ratio.