JPH09199085A - Fluorescent lamp and lighting system using it - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve a luminous flux maintenance factor without reducing the light outputs of near infrared rays and visible light by forming an AL lower phosphor layer on the inner face side of a container, and providing a protective layer made of a metal oxide between the AL lower phosphor layer and the container. SOLUTION: A fluorescent lamp 10 generates an electric discharge in it, and it is provided with a translucent airtight container 1, a phosphor layer 6, and a protective layer. The phosphor layer 6 is constituted of iron-activated lithium aluminate phosphors and threewavelength area luminescence type phosphors serving as phosphors emitting visible light. The phosphor layer 6 is formed in layers, and it is constituted of the first layer on the inner face side of the container 1 mainly made of the iron-activated lithium aluminate phosphors and the second layer on the discharge space side mainly made of phosphors emitting visible light. The protective layer is formed between the inner face of the container 1 and the first layer, and it is made of ultra-fine grains of alumina.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fluorescent lamp having an emission peak wavelength in a near infrared region and a visible light region and an illuminating device using the fluorescent lamp.

[0002]

2. Description of the Related Art Fluorescent lamps having a light emission intensity in the near infrared region and visible light region such as wavelengths of 650 nm to 800 nm are used as light sources for plant cultivation.

A conventional fluorescent lamp has an iron-activated lithium aluminate phosphor (LiAlO ₂ : Fe, LiAlO ₂ : Fe, as described in Japanese Patent Application Laid-Open No. 52-89281) for increasing the emission intensity in the near infrared region. Hereinafter, ALF phosphor) was used. The ALF phosphor has an emission peak wavelength at 740 nm and is effective in increasing the emission intensity in the near infrared region.

On the other hand, Japanese Patent Application Laid-Open No. 7-220682 discloses a fluorescent lamp in which an ALF phosphor and a three-wavelength light emitting phosphor are formed in layers. This fluorescent lamp is
The three-wavelength band emission phosphor layer is formed on the inner surface of the glass tube, and the ALF phosphor is formed on the discharge space side. This is AL
Since lithium contained in the F phosphor substitutes for sodium in the glass tube and affects the mechanical strength of the glass tube,
By forming an ALF phosphor on the discharge space side, substitution of lithium with sodium is suppressed.

[0005]

[Problems to be Solved by the Invention] However, ALF
The phosphor has a property of easily binding to mercury. ALF
When the phosphor layer is formed so that the phosphor faces the discharge space side, mercury in the discharge space is adsorbed by the ALF phosphor to deteriorate the phosphor layer, and the adsorbed mercury causes a change in the mercury emission line emitted by the discharge. It will absorb 254 nm ultraviolet light. As a result, there is a problem in that the light output of near-infrared rays and visible rays output from the phosphor layer is reduced, and the luminous flux maintenance factor is reduced.

The present invention solves the above-mentioned problems, and provides a fluorescent lamp capable of improving the luminous flux maintenance factor without lowering the light output of near infrared rays and visible rays, and an illuminating device using this fluorescent lamp. The purpose is to do.

[0007]

A fluorescent lamp according to a first aspect of the present invention includes a translucent airtight container in which electric discharge is generated and mercury and a rare gas are enclosed; and an inner surface side of the airtight container. Emission peak wavelength is 700-800 nm
Which is composed of a first layer mainly composed of an iron-activated lithium aluminate phosphor in the region of the above and a second layer mainly composed of a phosphor which emits visible light and which is formed on the discharge space side. A body layer; and a protective layer made of a metal oxide provided between the inner surface of the airtight container and the first layer.

In the present and subsequent claims, the light-transmitting hermetic container is formed of a light-transmitting material such as soda lime glass or borosilicate glass and has a discharge space. The container is not limited to a straight pipe type, but a ring type, U-shaped, W-shaped,
The shape may be an H shape, a saddle shape, a flat plate shape, or the like.

Mercury and a rare gas are enclosed in the container, and a rare gas containing xenon and several torr of an inert gas such as argon, krypton or neon is allowed.

As a means for causing a discharge, a hot cathode type or cold cathode type internal electrode arranged inside the container, an external electrode arranged outside the container, an excitation coil for applying a high frequency electromagnetic field, etc. are applied. It is possible.

The phosphor that emits visible light in the phosphor layer can be, but is not limited to, a halophosphate phosphor and a three-wavelength-emitting phosphor.

The protective layer may be made of a metal oxide having a good transmittance in the near infrared and visible light regions, and the film thickness thereof is 0.
The thickness is preferably in the range of 1 to 5.0 μm, but may be set to a desired film thickness according to the transmittance of near infrared rays and visible light or the manufacturing conditions of the fluorescent lamp.

In the fluorescent lamp of claim 1, since the ALF phosphor is formed as the first layer on the inner surface side of the container so as not to face the discharge space, mercury is blocked by the second layer and the ALF phosphor is removed. In addition to being less likely to be adhered to, the protective layer can also suppress the reaction between the alkaline component in the container and the ALF phosphor.

Further, in the case of a fluorescent lamp which is generally lit at a tube wall load of 500 W / m ² or more, mercury is struck from the discharge space side so as to pass through the phosphor layer, and many ultraviolet rays pass through the phosphor layer. Then, the container is irradiated. For this reason,
Alkali components from the glass constituting the container are deposited and react with the phosphor, causing phenomena such as deterioration of the brightness of the phosphor and blackening of the glass, leading to a reduction in the luminous flux maintenance factor.

In the fluorescent lamp of the first aspect, since a large amount of mercury and ultraviolet rays are blocked by the protective layer made of a metal oxide, even in a fluorescent lamp having a high complete wall load, the reaction between mercury and the container is suppressed and at the same time. The precipitation of alkali components from the glass constituting the container is suppressed, and the deterioration of the ALF phosphor is effectively improved.

A fluorescent lamp according to a second aspect of the present invention is a translucent airtight container in which electric discharge is generated and mercury and a rare gas are sealed; and an emission peak wavelength is 700 to 800 nm on the inner surface side of the airtight container. A phosphor layer which is mainly composed of an iron-activated lithium aluminate phosphor and a phosphor which emits visible light in the region, and a phosphor layer in which at least the iron-activated lithium aluminate phosphor is coated with a metal oxide; It is characterized by having.

The ALF phosphor and the phosphor that emits visible light may be mixed to form a phosphor layer or may be formed in layers. Also in the case of forming a layer, a layer mainly containing the ALF phosphor may be formed on the discharge space side, or may be formed on the inner surface side of the container as in claim 1.

The amount of metal oxide coated on the ALF phosphor is 1 to 10 wt% with respect to the phosphor. The coating of the metal oxide is obtained by wet mixing fine particle metal oxide having an average particle diameter of 0.01 to 0.5 μm with phosphor fine particles having an average particle diameter of about 10 μm, and then drying at 600 to 700 ° C. be able to.

Further, the coating can improve the deterioration of the phosphor even if it does not cover the entire surface of the ALF phosphor as in the case of a continuous film, but it may be constructed as a continuous film.

In the fluorescent lamp of the second aspect, since the ALF phosphor is coated with the metal oxide, the mercury is blocked by the metal oxide and is hard to be attached to the ALF phosphor, and the coating of the metal oxide is provided. The reaction between the alkaline component in the container and the ALF phosphor can also be suppressed.

According to a third aspect of the present invention, in the fluorescent lamp according to the first or second aspect, the metal oxide is mainly Al ₂
It is characterized by comprising at least one of O ₃ , TiO ₂ , SiO ₂ , ZnO, CeO ₂ , and Y ₂ O ₃ .

Since the metal oxide described in claim 3 is excellent in blocking mercury and ultraviolet rays and has a high visible light transmittance, it is suitable as the protective film of claim 1 or the coating of claim 2. .

The invention according to claim 4 is the fluorescent lamp according to any one of claims 1 to 3, characterized in that an amalgam is contained in the airtight container as a mercury vapor pressure control means.

As a mercury vapor pressure control means, an amalgam (Bi-In) composed of mercury, bismuth and indium is used.
-Hg) and the like, but not limited thereto.

A fluorescent lamp using an amalgam as a mercury vapor pressure control means has an effect that the amalgam regulates the mercury vapor pressure in the discharge space to an optimum pressure when it is stably lit, but the mercury vapor pressure is high at the time of starting. Can occur for several tens of minutes to several hours. In this way, if the state of high mercury vapor pressure continues for a long time, the amount of mercury ions implanted into the phosphor and the container increases, and the deterioration of the phosphor and the coloring (blackening) of the container tend to be accelerated. is there.

According to the fourth aspect, even when the ALF phosphor is used in such a state, it is difficult for mercury to be attached, and deterioration of the ALF phosphor can be suppressed.

According to a fifth aspect of the present invention, in the fluorescent lamp according to any one of the first to fourth aspects, the phosphor that emits visible light in the phosphor layer is a three-wavelength band emission type phosphor. To do.

Examples of the three-wavelength band emission type phosphor include, for example,
Y ₂ O ₃ : Eu ³⁺ as a red phosphor having a peak wavelength near 600 to 630 nm, and a green phosphor having a peak wavelength near 520 to 550 nm (La, Ce, T).
b) PO ₄ , (Sr, Ca, Ba) ₁₀ (P as a blue-based phosphor having a peak wavelength near ₄₀₀ to 500 nm
O ₄ ) ₆ Cl ₂ : Eu ²⁺ or BaMg ₂ Al ₁₆ O ₂₇ : Eu
²⁺ can be used, but it may be a combination with another phosphor as long as it is a light emitting type of three wavelengths.

According to a fifth aspect, the phosphor that emits visible light is 3
Since it is a wavelength-emitting phosphor, visible light is efficiently output.

The fluorescent lamp of the invention of claim 6 is the fluorescent lamp of claim 1.
The fluorescent lamp according to any one of 1 to 5 is integrated with a lighting circuit, and a bulb-shaped fluorescent lamp is configured with a base connected to the lighting circuit.

The lighting circuit includes an electronic ballast, a choke coil type ballast and the like, and may be of a high frequency lighting system. The container may have a structure covered with gloves or the like or a structure exposed to the outside.

Since the bulb-type fluorescent lamp has a container such as a glass tube in a bent shape to achieve high density and is small in size and has high output, the load on the tube wall is higher than that of a general fluorescent lamp. Therefore, the amount of mercury injected into the phosphor layer is likely to increase.

According to the sixth aspect, even when the ALF phosphor is used in such a compact fluorescent lamp, mercury is not easily attached,
It is possible to suppress the deterioration of the ALF phosphor.

An illumination device according to claim 7 is the illumination device according to any one of claims 1 to 6.
The fluorescent lamp according to any one of the above is used as a light source.

The lighting device is not limited to the outdoor type and the direct ceiling type, but can be applied to various lighting devices such as a pendant, a downlight, and a bracket. The main body of the lighting device is made of metal such as aluminum and iron, glass, ceramics, resin, or the like.

[0036]

1 to 6 show an embodiment of the present invention.
This will be described with reference to FIG.

FIG. 1 is a conceptual diagram showing a straight tube type fluorescent lamp according to the first embodiment.

The fluorescent lamp 10 has a rated power of 20 W. Reference numeral 1 is a translucent airtight container having a straight tube shape. The container 1 has an outer diameter of 28 mm and a tube length of about 580 mm, and is made of, for example, soda lime glass. Both ends of the container 1 are sealed by stems 2 and 2, and lead wires 3 and 3 are hermetically penetrated through the stems 2 and 2. The lead wires 3 and 3 are attached with filament electrodes 4 and 4 as a means for generating an electric discharge. These electrodes 4 and 4 are formed into a double coil by a tungsten wire or the like, and an emitter (not shown) is applied thereto. ing.

Reference numeral 6 denotes a phosphor layer, which is an iron-activated lithium aluminate phosphor (LiAlO ₂ : Fe, hereinafter referred to as ALF phosphor) and a phosphor which emits visible light (hereinafter referred to as visible light emitting phosphor). ) As a three-wavelength band emission type phosphor.

FIG. 2 is a sectional view of a surface of the fluorescent lamp shown in FIG. 1 which is orthogonal to the tube axis direction. In the present embodiment, the phosphor layer 6 has a layered structure, and the first layer 6a on the inner surface side of the container 1 mainly composed of the ALF phosphor and the first layer 6a on the discharge space side mainly composed of the visible light emitting phosphor. And two layers 6b. The film thickness of the first layer 6a and the second layer 6b is 10 to
It is formed in the range of 30 μm.

Reference numeral 7 is a protective layer, which is formed between the inner surface of the container 1 and the first layer 6a to have a film thickness of about 1.0 μm.
It is composed of ultrafine particles of alumina (Al ₂ O ₃ ).

FIG. 3 is a graph showing the relationship between the lighting time and the luminous flux maintenance factor of the fluorescent lamp of this embodiment. Curve I
Represents the change in the luminous flux maintenance factor of the first embodiment. For comparison, the first layer is mainly composed of the ALF phosphor, and the second layer is the second.
As a conventional example, a fluorescent lamp in which a visible light phosphor is formed in each layer with the same thickness is shown.

The fluorescent lamp 10 of the present embodiment is 400
Even after 0 h, the luminous flux maintenance factor was 90% or more, while that of the conventional fluorescent lamp was 65% or less. It is considered that this is because a large amount of mercury is adsorbed on the ALF phosphor of the conventional fluorescent lamp, the phosphor layer is deteriorated, and the adsorbed mercury absorbs the ultraviolet ray of 254 nm of the mercury emission line. As a result, the light output of near-infrared light and visible light output from the phosphor layer is reduced, and the luminous flux maintenance factor is reduced.

The spectral spectrum intensity in the near infrared region of 700 to 800 nm was also measured. After 2000h, the relative value with the initial value as 100% is 78% in the conventional example.
In contrast, the fluorescent lamp of the first embodiment has 9
It was 0%, and it was confirmed that the ALF phosphor was less deteriorated.

FIG. 4 is a conceptual diagram showing an illuminating device equipped with the fluorescent lamp of the first embodiment.

Reference numeral 30 denotes a main body of a lighting device directly attached to the ceiling, and lamp sockets 31, 3 are provided at both longitudinal ends of the main body 30 of the fixture.
1 are arranged to face each other. These sockets 3
The fluorescent lamp 10 is mounted between the terminals 1 and 31 by engaging the base pins 9 of the bases 8 and 8. The fixture body 30 contains a lighting circuit including a ballast 32 for lighting the lamp 10. According to this lighting device, it is possible to provide a lighting device that emits a large amount of near infrared rays.

FIG. 5 is a sectional view showing a fluorescent lamp according to the second embodiment. Fluorescent lamp 10 of the second embodiment
Is the structure of the first embodiment and the phosphor layer 6 shown in FIG.
The configuration other than the above is the same, and the description of the same parts will be omitted.

In the present embodiment, the surface of the ALF phosphor fine particles is made of alumina fine particles (Al
₂ O ₃ ). The amount of alumina fine particles to be coated is 5 wt% with respect to the weight of the phosphor. The phosphor layer 6 is a first layer on the inner surface side of the container 1 which is mainly composed of ALF phosphor.
Layer 6a, and a second layer 6b on the side of the discharge space mainly composed of a visible light emitting phosphor. Although the protective layer is not formed in the second embodiment, it may be formed if necessary.

The relationship between the lighting time and the luminous flux maintenance factor of the fluorescent lamp of the second embodiment is represented by the curve II in FIG.
The measuring method is the same as that of the first embodiment. Also in the fluorescent lamp 10 of the second embodiment, the luminous flux maintenance factor was about 85% even after 4000 hours had passed.

Further, the spectral spectrum intensity in the near infrared region of 700 to 800 nm was 85% as a relative value with the initial value being 100% after 2000 hours, and it was confirmed that the ALF phosphor was less deteriorated. Was done.

The phosphor in which the surface of the ALF phosphor fine particles is coated with a metal oxide is formed mainly as the second layer 6b in addition to the first layer 6a as shown in FIG. The first layer 6a may be formed mainly of a visible light emitting phosphor. Alternatively, the ALF phosphor and the visible light emitting phosphor may be mixed to form a single layer instead of being formed into a layer.
This is because mercury is less likely to adhere to the ALF phosphor fine particles themselves because the surface is covered with the metal oxide.

FIG. 6 is a partially cutaway sectional view showing a light bulb shaped fluorescent lamp according to the third embodiment.

Reference numeral 40 is a light bulb type fluorescent lamp, 41 is a container made of lead glass in which a bulb having an outer diameter of 12 mm is bent and formed in a saddle shape, and 42 is a lighting circuit 4 made of an inverter device.
A cover for accommodating 3 and a reference numeral 44 are light-diffusing gloves having a translucency attached to the cover 42 so as to cover the container 41. Reference numeral 45 denotes a partition board provided on the cover 42, which divides a space between the lighting circuit 43 side of the lighting circuit 43 cover 42 and the container 41 side, and also defines the lighting circuit 43 and the container 4
Supports 1.

Reference numeral 46 denotes a phosphor layer formed on the inner surface of the container 41, which is formed by mixing ALF phosphor fine particles whose surface is covered with alumina fine particles and visible light emitting phosphor. Reference numeral 47 is a filament electrode disposed on a stem formed at the end of the container 41, and is formed at both ends of the container 41. Reference numeral 48 is an auxiliary amalgam made of mercury, indium, or the like, which is arranged on the lead wire of the electrode 41. The auxiliary amalgam 48 evaporates mercury at a desired mercury vapor pressure by the heat of the electrode 47 so that the luminous flux rises favorably at the start of lighting. Reference numeral 49 denotes an exhaust pipe provided on the stem, and the main amalgam 50 made of mercury, bismuth, and indium is fixed to the exhaust pipe 49.
A feeding pin 51 is provided upright on the lighting circuit 43, and an outer lead 52 connected to the electrode 47 is wound. Reference numeral 53 is an E26 type base attached to the top of the cover 42, and is electrically connected to a power input section (not shown) of the lighting circuit 43.

The electric bulb type fluorescent lamp 40 has an input power of 1
5W, lamp current 200mA, tube wall load 1100W / m
Illuminated at ² . The mercury vapor pressure is about 8 times higher than that during stable lighting for about 30 minutes from the start of lighting until it becomes stable.
The amount of mercury injected into the phosphor layer 6 increases. Further, even when the fluorescent lamp is stably lit, since the fluorescent lamp is lit with a high load, the lamp temperature becomes high and the amount of mercury injected becomes large.

However, in the present embodiment, since the surfaces of the ALF phosphor fine particles are coated with the alumina fine particles (Al ₂ O ₃ ), the adhesion of mercury to the ALF phosphor is suppressed, and the luminous flux maintenance factor is large. 700-800 without deterioration
The spectral spectrum intensity in the near infrared region of nm does not decrease. Further, since the alkaline component of the container 41 and the ALF phosphor are less likely to be replaced, the mechanical strength of the container 41 is also improved.

Although the protective layer is not formed in the third embodiment, it may be formed if necessary. Further, the globe 44 is not always necessary, and the container 41 may be exposed to the outside, for example. Furthermore, the phosphor layer 6
In addition to the mixture of the ALF phosphor and the visible light-emitting phosphor, each may be formed in a layer shape as in the first or second embodiment.

The fluorescent lamps and lighting devices of the first to third embodiments described above are particularly suitable for use as a light source and lighting device for plant cultivation because of their spectral distribution characteristics and luminous flux maintenance factor. .

[0059]

According to the fluorescent lamp of the present invention and the illuminating device using the fluorescent lamp, it becomes difficult for mercury to adhere to the ALF fluorescent material, and the alkaline component and A
Since the reaction with the LF phosphor can also be suppressed, the luminous flux maintenance factor can be improved without lowering the optical output of near infrared rays and visible light.

[Brief description of drawings]

FIG. 1 is a conceptual diagram showing a straight tube type fluorescent lamp according to a first embodiment of the present invention.

FIG. 2 is a cross-sectional view of a surface of the fluorescent lamp of FIG. 1 which is orthogonal to the tube axis direction.

FIG. 3 is a graph showing the relationship between the lighting time of the fluorescent lamp and the luminous flux maintenance factor.

FIG. 4 is a conceptual diagram showing an illumination device equipped with the same fluorescent lamp.

FIG. 5 is a sectional view showing a fluorescent lamp according to a second embodiment of the present invention.

FIG. 6 is a partially cutaway sectional view showing a light bulb shaped fluorescent lamp according to a third embodiment of the present invention.

[Explanation of symbols]

 1, 41 ... Translucent airtight container, 6, 46 ... Phosphor layer, 6a ... First layer, 6b ... Second layer, 10 ... Fluorescent lamp, 30 ... Lighting device body, 40 ... Light bulb type fluorescent lamp, 50 ... Amalgam.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Akira Taya 4-3-1, Higashishinagawa, Shinagawa-ku, Tokyo Inside Toshiba Litec Co., Ltd.

Claims (7)

[Claims] 1. A translucent airtight container in which a discharge is generated inside and mercury and a rare gas are sealed; and an emission peak wavelength provided on the inner surface side of the airtight container is 700 to 80.
It was composed of a first layer mainly composed of iron-activated lithium aluminate phosphor in a region of 0 nm and a second layer mainly composed of a phosphor emitting visible light formed on the discharge space side. A fluorescent lamp, comprising: a phosphor layer; and a protective layer made of a metal oxide provided between the inner surface of the airtight container and the first layer. 2. A light-transmissive airtight container in which electric discharge is generated and mercury and a rare gas are sealed; and iron activation on the inner surface side of the airtight container whose emission peak wavelength is in the range of 700 to 800 nm. A lithium aluminate phosphor and a phosphor that emits visible light as a main component, and a phosphor layer in which at least the iron-activated lithium aluminate phosphor is coated with a metal oxide; And a fluorescent lamp. 3. The metal oxides are mainly Al ₂ O ₃ and Ti.
The fluorescent lamp according to claim 1 or 2, wherein the fluorescent lamp is made of at least one of O ₂ , SiO ₂ , ZnO, CeO ₂ , and Y ₂ O ₃ . 4. The fluorescent lamp according to claim 1, wherein the hermetic container contains amalgam as a mercury vapor pressure control means. 5. The fluorescent lamp according to claim 1, wherein the phosphor that emits visible light in the phosphor layer is a three-wavelength band emission type phosphor. 6. The fluorescent lamp according to any one of claims 1 to 5 and a lighting circuit are integrated, and a bulb-shaped fluorescent lamp is configured with a base connected to the lighting circuit. Characteristic fluorescent lamp. 7. An illuminating device using the fluorescent lamp according to claim 1 as a light source.