JP2003272559A - Fluorescent lamp - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a fluorescent lamp causing little drop of luminous flux along with elapse of a lighting time, and having high luminous flux. <P>SOLUTION: This fluorescent lamp has a function capable of generating discharge by inputting power into a glass bulb filled with mercury and a rare gas inside, and is provided with a protective film on the inside wall of the glass bulb, and a phosphor layer mainly containing a phosphor on the protective film. The fluorescent lamp is composed by including, in the protective film, small particles of a phosphor having a central particle diameter (D<SB>50</SB>) in the range of 1.0 μm<D<SB>50</SB>≤4.0 μm, and fine particles of a metal oxide having a central particle diameter (D<SB>50</SB>) in the range of 0.05 μm<D<SB>50</SB>≤1 μm. Preferably, at least one metal oxide selected from a group comprising aluminum oxide, silicon oxide, titanium oxide, zinc oxide and yttrium oxide is used for the metal oxide. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a fluorescent lamp.

[0002]

2. Description of the Related Art Conventionally, a fluorescent lamp having a function of applying electric power to a glass bulb in which mercury and a rare gas are enclosed to generate electric discharge, and a phosphor layer is provided on an inner wall of the glass bulb. It has been known.

Such a fluorescent lamp has a problem that the luminous flux gradually decreases as the lighting time elapses. One of the causes of the decrease in luminous flux is that the transparent glass bulb is colored by the chemical reaction between the mercury enclosed in the glass bulb and the glass material constituting the glass bulb.

The above coloring phenomenon will be described in detail below. That is, during the lighting of the fluorescent lamp, a phenomenon occurs in which a part of the mercury vapor passes through the gap between the phosphor layers and reaches the glass bulb. Further, the glass bulb generally contains a considerable amount of sodium as a constituent material thereof, and this sodium is deposited on the surface of the glass bulb by the heat during the lighting of the fluorescent lamp. In addition, this precipitation of sodium has a wavelength of 4
It is also known that it may be accelerated by irradiation with ultraviolet rays of 00 nm or less. Therefore, while the fluorescent lamp is lit, mercury that has passed through the phosphor layer comes into contact with sodium deposited on the surface of the glass bulb, and mercury and sodium chemically react to form an amalgam that does not have a light-transmitting property. This causes the phenomenon that the glass bulb is colored. Since this phenomenon becomes apparent with the lighting time of the fluorescent lamp, the luminous flux of the fluorescent lamp decreases with the lighting time.

As a means for solving such a problem, conventionally, a protective film is provided between the inner wall of the glass bulb and the phosphor layer to prevent mercury from coming into contact with the glass bulb. As the protective film, fine particles of a metal oxide (aluminum oxide, silicon oxide, titanium oxide, zinc oxide, etc.) having a central particle diameter (D ₅₀ ) of about 0.01 to 1 μm are preferably used, and the thickness of the protective film As 0.1-3.0
A thickness of about μm is preferably used.

Further, as described in, for example, Japanese Patent Application Laid-Open No. 9-153345, the protective film has a mean particle size (substantially the same as the central particle size D ₅₀ ) of 1.0 μm or less and a fluorescence of 0.1 μm or more. It has been devised to solve the above problems by using small particles in the body. Furthermore, for example, JP-A-9-9221
As described in Japanese Patent Laid-Open No. 5 (1994), it has been devised to solve the above problems by forming the protective film with ultrafine particles of a phosphor having an average particle size of 150 nm or less.

[0007]

However, in the conventional fluorescent lamp provided with the protective film, the chemical reaction between mercury and the glass material is suppressed, and the luminous flux is prevented from gradually decreasing with the passage of lighting time. However, there is a problem that it is difficult to achieve both the improvement of the luminous flux of the fluorescent lamp and the improvement of the luminous flux of the fluorescent lamp.

That is, the average particle size of the protective film is 1 μm.
In the case of a fluorescent lamp composed of the following metal oxide fine particles, it is possible to suppress the chemical reaction between mercury and the glass material, and to suppress the problem that the luminous flux gradually decreases with the passage of lighting time, but the metal There is a problem that the luminous flux is low because the oxide fine particles are not only a non-luminous substance that does not emit light under ultraviolet irradiation but also have a property of slightly absorbing visible light. In addition, as described in JP-A-9-153345 and JP-A-9-92215, the protective film has a small particle size of the phosphor of 1.0 μm or less and 0.1 μm or more, or an average particle size of the protective film. In the case of being composed of ultrafine particles of a phosphor having a diameter of 150 nm or less, the light emission efficiency of the phosphor is low due to the small size of the phosphor particles, and thus the light emission efficiency of the protective film is also low and the lighting time Although it is possible to suppress the problem that the luminous flux gradually decreases with the passage of time, there is a problem that the luminous flux of the fluorescent lamp is still low.

Further, for example, when the protective film is composed of phosphor particles having an average particle size of more than 1.0 μm, in general, the larger the average particle size of the phosphor particles is, the more the fluorescence is increased. Since the luminous efficiency of the body particles is increased, the luminous flux of the fluorescent lamp is improved. However, because the average particle size of the phosphor particles is large, many gaps are created in the protective film, the chemical reaction between mercury and the glass material cannot be suppressed, and the problem that the luminous flux gradually decreases with the passage of lighting time is remarkable. There is a problem.

The present invention has been made to solve the above problems, and an object of the present invention is to provide a fluorescent lamp having a high luminous flux with less reduction in luminous flux with the passage of lighting time.

[0011]

In order to achieve the above object, the fluorescent lamp of the present invention has a function capable of generating an electric discharge by applying power to a glass bulb in which mercury and a rare gas are enclosed. A fluorescent lamp having a protective film on the inner wall of the glass bulb, and a phosphor layer mainly composed of a phosphor on the protective film, wherein the protective film has a central particle diameter (D ₅₀ ) of 1 Small particles of the phosphor within the range of 0.0 μm <D ₅₀ ≦ 4.0 μm and the central particle size (D ₅₀ ) of 0.005 μm
It is characterized by containing fine particles of a metal oxide within a range of m ≦ D ₅₀ ≦ 1 μm.

The median particle diameter of the small particles of the phosphor is 1.0.
It is necessary to be in the range of μm <D ₅₀ ≦ 4.0 μm, but preferably in the range of 1.5 μm ≦ D ₅₀ ≦ 3.0 μm. As a result, the protective film of the fluorescent lamp contains small particles of a phosphor having a relatively large central particle size and high luminous efficiency in the film, so that the protective film emits relatively strong fluorescence when irradiated with ultraviolet rays. become. The center particle size of the metal oxide particles is 0.005.
It is necessary to be in the range of μm ≦ D ₅₀ ≦ 1 μm, preferably 0.005 μm ≦ D ₅₀ ≦ 0.1 μm, more preferably 0.005 μm ≦ D ₅₀ ≦ 0.03.
It is desired to be in the range of μm. Within this range, voids are rarely formed in the protective film, and a dense protective film can be formed.

Due to the synergistic effect of the above-mentioned small particles of the phosphor and the fine particles of the metal oxide, it has a function of suppressing the chemical reaction between mercury and the glass material and suppressing the problem that the luminous flux gradually decreases with the passage of lighting time. Not only a protective film can be formed, but also a protective film having a function of emitting highly efficient fluorescence by ultraviolet rays generated by mercury discharge.
As described above, since the fluorescent lamp of the present invention is provided with the protective film having both of the above-mentioned two functions, the decrease in luminous flux with the passage of the lighting time of the fluorescent lamp is reduced, and at the same time, high luminous flux fluorescence can be realized.

Further, in the fluorescent lamp of the present invention, the metal oxide is preferably at least one metal oxide selected from the group consisting of aluminum oxide, silicon oxide, titanium oxide, zinc oxide and yttrium oxide.

These metal oxides are not only relatively inexpensive and easily available, but also have the property of absorbing ultraviolet rays. Therefore, when the protective film is formed by using these metal oxides, the ultraviolet rays generated by mercury discharge are hard to reach the glass bulb through the phosphor layer or the protective film. Sodium is less likely to deposit during the operation of the fluorescent lamp, and the reaction between mercury and sodium can be further suppressed.

Further, in the fluorescent lamp of the present invention, it is preferable that the metal oxide fine particles are fluorescent fine particles.
As a result, the fine particles of the metal oxide become fine particles that also have a function of emitting fluorescence, so that the protective film has a function of emitting fluorescence with even higher efficiency, and a fluorescent lamp with even higher luminous flux can be realized.

Further, in the fluorescent lamp of the present invention, the small particles of the phosphor are small particles of a phosphor mainly composed of at least a compound represented by any one of the following chemical formulas (1) to (3). Preferably there is. _{(1) (Ba 1-ax} Sr a Eu x) (Mg 1-y Mn y) Al 10 O 17 The above formula (1) is, (Ba, Sr) MgAl ₁₀
It can also be described as O ₁₇ : Eu ²⁺ , Mn ²⁺ . (2) (Ba _1-abcx Sr _a Ca _b Mg _c Eu _x ) ₁₀ (PO ₄ ) ₆ Cl _{2 The} above chemical formula (2) is (Ba, Sr, Ca, M
g) It can also be described as ₁₀ (PO ₄ ) ₆ Cl ₂ : Eu ²⁺ . (3) (Y _1-x Eu _x ) ₂ O ₃ The chemical formula (3) can also be described as Y ₂ O ₃ : Eu ³⁺ .

However, x, y, a, b, and c are 0.
01 ≦ x ≦ 0.3, 0 ≦ y ≦ 0.1, 0 ≦ a ≦ 1, 0 ≦
It is a numerical value that satisfies b <1 and 0 ≦ c <1.

Small particles of a phosphor mainly composed of the compounds represented by the chemical formulas (1) to (3) (hereinafter, B respectively)
AM small particles, SCA small particles, YOX small particles)
Both are high-efficiency phosphor small particles, the BAM small particles and SCA small particles are blue phosphors, and the YOX small particles are red phosphors. Therefore, by using these, the protective film is blue or red. It emits high-intensity fluorescent light. on the other hand,
Since the main body of fluorescence of the fluorescent lamp is the light emission from the phosphor layer, for example, when a desired light color (white, daylight color, neutral white, bulb color, etc.) is to be obtained, the above-mentioned fluorescent light is applied to the protective film. By using the body, it is possible to increase the ratio of the green component of the light emitted by the phosphor layer. The green component of the light emission has high visibility, and since this green component is the light emission from the phosphor layer composed of phosphor particles having extremely high light emission efficiency, as a result, in comparison between fluorescent lamps emitting the same light color, ,
The luminous flux of the fluorescent lamp of the present invention is higher than that of the conventional fluorescent lamp. In addition, since a fluorescent lamp containing the same high-efficiency phosphor in the protective film as the fluorescent material used in the three-wavelength band emission type fluorescent lamp, the material is not available as a fluorescent lamp having a protective film containing phosphor particles. It will be relatively easy.

Further, the fluorescent lamp of the present invention is preferably a three-wavelength band emission type fluorescent lamp. Since the three-wavelength band emission type fluorescent lamp is originally a fluorescent lamp of high luminous flux which emits light of high color rendering property, this makes it possible to obtain a fluorescent lamp of higher luminous flux than that of emitting light of high color rendering property.

In the three-wavelength emission type fluorescent lamp, the phosphor layers emit at least three kinds of phosphors (red phosphor, green phosphor, red phosphor) which emit red, green and blue lights, respectively. It is a fluorescent lamp as a main component, and the following phosphors are exclusively used as the red phosphor, the green phosphor, and the blue phosphor, respectively (see Phosphor Handbook: Ohmsha). (Red phosphor) The above Y ₂ O ₃ : Eu ³⁺ phosphor and the like. (Green phosphor) CeMgAl ₁₁ O ₁₉ : Tb ³⁺ phosphor, L
aPO ₄ : Tb ³⁺ phosphor, (Ce, Gd) MgB ₅ O ₁₀ :
Tb ³⁺ phosphor, etc. (Blue phosphor) (Ba, Sr) MgAl described above
₁₀ O ₁₇ : Eu ²⁺ , Mn ²⁺ phosphor, (Ba, Sr, Ca,
Mg) ₁₀ (PO ₄ ) ₆ Cl ₂ : Eu ²⁺ phosphor and the like.

[0022]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the fluorescent lamp of the present invention will be described below with reference to the drawings, but the present invention is not limited to the following fluorescent lamps.

FIG. 1 is a sectional view of the fluorescent lamp of the present invention. Further, FIG. 2 is an enlarged view of a portion A of FIG. In FIG. 1, 1 is a phosphor layer, 2 is a protective film, 3 is a glass bulb, 6 is mercury vapor, 7 is a rare gas, 8 is a filament, and 9
Is a base, 10 is an electrode, 11 is a stem, and 12 is a fluorescent lamp. In addition, in FIG. 2, 4 is a small particle of the phosphor, and 5 is a metal oxide.

The glass bulb 3 is a base body which constitutes the fluorescent lamp 12, and is made of a glass material. The composition of the glass material and the shape and size of the glass bulb 3 are not particularly limited as long as they have translucency and are not brittle. The shape of the glass bulb 3 includes, for example, a tubular shape, an annular shape, and a glove shape.

The protective film 2 suppresses the mercury vapor 6 penetrating into the phosphor layer 1 from coming into contact with the glass bulb 3 and chemically reacting with each other, and the ultraviolet rays passing through the phosphor layer 1 are protected by the glass bulb 3. It is also possible to prevent the above-mentioned chemical reaction from being accelerated by irradiating with. at the same time,
It is also possible to suppress the blackening and discoloration of the glass bulb 3 caused by the chemical reaction, and to suppress the decrease in luminous flux of the fluorescent lamp 12 that occurs with the passage of lighting time. The thickness of the protective film 2 is not particularly limited, but can be, for example, 1 μm or more and 50 μm or less. The thickness is 0.0
The protective film 2 may be such that the phosphor small particles 4 are scattered on the metal oxide film having a size of about 5 μm or more and less than 4 μm. If the thickness of the protective film is thinner than the above range, the function as the protective film that suppresses the chemical reaction between the above-mentioned mercury and the glass bulb may not be effectively exhibited, and if it is thicker than the above range, Since the protective film 2 impedes the intensity of light emitted by the phosphor layer 1, the luminous flux of the fluorescent lamp 12 may decrease.

In the fluorescent lamp of the present invention, the protective film 2 has a central particle diameter (D ₅₀ ) of 1.0 μm <D ₅₀ ≦ 4.0 μm, and a small particle of the phosphor and a central particle diameter (D ₅₀ ). ₅₀ ) is 0.00
It is characterized in that it comprises fine particles of a metal oxide or fine particles of a phosphor within the range of 5 μm ≦ D ₅₀ ≦ 1 μm. This makes it possible to prevent the transmission of mercury while increasing the luminous flux.

As the small particles 4 of the phosphor, particularly blue
Alternatively, a phosphor that emits red light is effective.
_Ten(PO_Four)₆Cl₂: Eu²⁺Blue phosphor, (Sr, C
a)_Ten(PO_Four)₆Cl₂: Eu²⁺Blue phosphor, (Sr,
Ca)_Ten(PO_Four)₆Cl₂・ NB ₂O₃: Eu²⁺Blue fluorescence
Body, BaMgAl_TenO₁₇: Eu²⁺Blue phosphor, (Ba,
Sr) MgAl_TenO₁₇: Eu²⁺, Mn²⁺Blue phosphor, B
aMg₂Al₁₆O₂₇: Eu^{2 +}Blue phosphor, BaMg₂Al
₁₆O₂₇: Eu²⁺, Mn²⁺Blue phosphor, Y₂O₃: Eu ³⁺Red
Small particles of phosphors such as color phosphors are effective. Ingredient
Physically, one of the following chemical formulas (1) to (3)
Small particles of the phosphor mainly composed of the compound shown are effective
Is. Phosphors selected from these alone or
Used in combination. (1) (Ba_1-axSr_aEu_x) (Mg_1-yMn_y) Al_TenO₁₇ (2) (Ba_1-abcxSr_aCa_bMg_cEu_x)_Ten(PO_Four)₆Cl₂ (3) (Y_1-xEu_x)₂O₃ However, x, y, a, b, and c are each 0.01 ≦ x ≦
0.3, 0 ≦ y ≦ 0.1, 0 ≦ a ≦ 1, 0 ≦ b <1, 0
It is a numerical value that satisfies ≦ c <1. In addition, the small
For the particles, Y is used as the raw material for the phosphor.₂O₃Rare earth oxides such as
SiO₂By adding oxides such as
It is also possible to improve the performance of the phosphor.

Further, as the fine particle metal oxide 5, a material having a property of absorbing ultraviolet rays is preferable, and, for example, aluminum oxide, silicon oxide, titanium oxide, zinc oxide, yttrium oxide and the like are effective. In addition, these materials are preferable because they are inexpensive and easily available.

The fluorescent layer 1 is a fluorescent layer emitted by the fluorescent lamp 12.
And is formed on the protective film 2.
The ultraviolet rays (not shown) emitted by the mercury discharge.
Mainly composed of a phosphor (not shown) that converts visible light
To do. The thickness of the phosphor layer 1 is not particularly limited.
However, for example, 3 μm or more and 50 μm or less, preferably 5 μm
It is not less than m and not more than 30 μm. Thicker or thinner than this
However, since the luminous flux of the fluorescent lamp 12 may become low,
If not, the problem of film peeling of the phosphor layer 1 is likely to occur.
If it is thin, the problem of film transparency (the phosphor layer 1 is transparent,
The filament 8 etc. can be seen from the outside of the fluorescent lamp,
Problem that the external appearance of the press is impaired) is likely to occur. the above
The properties and types of phosphors are also not particularly limited.
Absent. Properties include, for example, phosphor powder and phosphor thin film.
It can be appropriately selected from a film, a phosphor thick film and the like. Of phosphor material
There is a wide selection of fluorescent materials for various lamps.
However, the preferred phosphor is a three-wavelength emission type fluorescent lamp.
Widely used for applications, (Sr, Ca)_Ten(PO_Four)₆
Cl₂: Eu²⁺Blue phosphor, (Ba, Ca, Mg)
_Ten(PO_Four)₆Cl₂: Eu²⁺Blue-green phosphor, BaMgA
l_TenO₁₇: Eu²⁺Blue phosphor, (Ba, Sr) MgAl
_TenO₁₇: Eu²⁺, Mn²⁺Blue-green phosphor, CeMgAl ₁₁
O₁₉: Tb³⁺Green phosphor, LaPO_Four: Ce³⁺, Tb³⁺
Green phosphor, GdMgB_FiveO_Ten: Ce³⁺, Tb³⁺Green firefly
Light body, GdMgB_FiveO_Ten: Ce³⁺, Mn²⁺Red phosphor,
Y₂O₃: Eu³⁺Red phosphor, 3.5MgO ・ 0.5Mg
F₂・ GeO₂: Mn⁴⁺For example, a red phosphor.

When the phosphor layer 1 is composed of the above-mentioned phosphor powder, it is preferable to use a phosphor powder having a central particle diameter of 1 μm or more and 30 μm or less, preferably 2 μm or more and 15 μm or less. Is preferable in terms of emission intensity (light flux).

The mercury vapor 6 is for obtaining ultraviolet rays (not shown) that excite the phosphor layer 1, and is enclosed in the glass bulb 3 together with the rare gas 7. The rare gas 7 is for adjusting the internal pressure of the glass bulb 3 to a reduced pressure atmosphere of several hundred Torr. Although not shown, the filament 8 is coated with an electron emissive material (emitter) made of BaO, SrO, CaO or the like, and emits thermoelectrons (not shown) for generating a discharge in the glass bulb 3. It is for doing. The electrode 10 is for energizing the filament 8, the stem 11 is for fixing the electrode 10, the base 9 protects the electrode 10 and the stem 11 from an impact, and the fluorescent lamp 12
This is to improve the appearance of.

The fluorescent lamp of the present invention may be a so-called cold cathode fluorescent lamp (a fluorescent lamp that does not have the filament 8 but has a cold cathode instead), or a so-called electrodeless fluorescent lamp (glass). There is no electrode 10 or filament 8 inside the bulb 3 and several kHz from the outside of the glass bulb 3
It may be a fluorescent lamp that applies high-frequency power of up to several GHz into the glass bulb 3 to excite the rare gas 7 and the mercury vapor 6 to generate discharge.

Further, in FIG. 1, a so-called electroded fluorescent lamp having the filament 8 and the electrode 10 at both ends of the glass bulb 3 is shown as an example, but the fluorescent lamp of the present invention is
The glass bulb having mercury and a rare gas enclosed therein has a function of generating electric discharge by applying electric power, a protective film is provided on an inner wall of the glass bulb, and a phosphor is mainly formed on the protective film. And a small particle of a phosphor having a central particle diameter in the range of 1.0 μm <D ₅₀ ≦ 4.0 μm.
Any fluorescent lamp may be used as long as it is a fluorescent lamp containing fine particles of a metal oxide having a central particle diameter within the range of 05 μm ≦ D ₅₀ ≦ 1 μm. It is not particularly limited. Therefore, the fluorescent lamp may generate a discharge by means other than that shown in FIG.

In the fluorescent lamp 12, as shown in FIG. 1, the glass bulb 3 is hermetically sealed, and the rare gas 7 and the mercury vapor 6 are contained inside.
To keep the inside of the glass bulb 3 in a predetermined decompressed atmosphere, and, for example, the filament 8 at both ends of the airtight space.
However, in the fluorescent lamp of the present invention, the shape and size of the fluorescent lamp 12, the wattage, the light color emitted by the fluorescent lamp 12 and the color rendering properties are not particularly limited. . The shape of the fluorescent lamp of the present invention includes, for example, a straight tube, a round shape, a double ring shape, a twin shape, a compact shape, a U shape, and a light bulb shape, and includes a thin tube for a liquid crystal backlight. Examples of the size include 4-type to 110-type. The wattage is several watts to hundreds of tens of watts, but is not limited to this. Examples of the light color include daylight color, neutral white color, white color, warm white color, light bulb color, and Palook color.

The operation of the fluorescent lamp 12 of the present invention will be described below.

When electric power is applied to the fluorescent lamp 12 shown in FIG. 1, a discharge is generated in the glass bulb 3 and the mercury vapor 6
Emits ultraviolet rays, and the ultraviolet rays irradiate the phosphor layer 1. Since the phosphor layer 1 is mainly composed of a phosphor that converts ultraviolet light into visible light, the phosphor layer 1 emits visible light when irradiated with ultraviolet light. Since the protective film 2 and the glass bulb 3 have a light-transmitting property, this visible light passes through the protective film 2 and the glass bulb 3 and is emitted to the outside. It should be noted that a part of the ultraviolet rays passes through the phosphor layer 1 and irradiates the protective film 2.

During the lighting of the fluorescent lamp 12, as described in the section of the prior art, a phenomenon occurs in which a part of the mercury vapor passes through the gap of the phosphor layer 1 unless the protective film 2 is provided, which causes the glass to disappear. The phenomenon that the bulb 3 is colored occurs. Therefore, the luminous flux of the fluorescent lamp 12 decreases with the lighting time.

However, in the fluorescent lamp according to the first aspect of the present invention, since the protective film 2 is constituted by including the particulate metal oxide 5 within the range of the central particle diameter described above, The gaps between the fine particles become dense, and the permeation of mercury can be prevented. Further, since it is configured to include the phosphor small particles 4 within the range of the central particle size described above, the protective film 2 has a high strength due to the ultraviolet rays transmitted and irradiated through the phosphor layer 1. It comes to emit fluorescence. At the same time, since the small fluorescent substance particles 4 absorb the ultraviolet rays and convert them into visible light, the intensity of the ultraviolet rays with which the glass bulb 3 is irradiated is weakened and the precipitation of sodium from the glass bulb 3 can be suppressed.

Further, in the fluorescent lamp according to claim 2 of the present invention, the fine particle metal oxide 5 is made of aluminum oxide, silicon oxide, titanium oxide, zinc oxide and yttrium oxide, which has a property of absorbing ultraviolet rays. Since it is at least one metal oxide selected from the group consisting of the following, the intensity of ultraviolet light irradiating the glass bulb 3 is further weakened, and the precipitation of sodium from the glass bulb 3 can be suppressed.

Further, in the fluorescent lamp according to claim 3 of the present invention, the fine particle metal oxide 5 is made into a fine particle fluorescent material having a function of absorbing ultraviolet rays and converting it into visible light. The intensity of ultraviolet light irradiating the glass bulb 3 is further weakened, so that not only the precipitation of sodium from the glass bulb 3 is suppressed, but also the protective film 2 emits fluorescence having a higher intensity.

Further, in the fluorescent lamp according to claim 4 of the present invention, the fluorescent small particles 4 are made into at least the fluorescent small particles emitting blue or red fluorescence described above, whereby the protective film 2 is formed. In the phosphor layer 1 which emits a strong intensity of fluorescence when white-based light is obtained, the visibility of the fluorescent component emitted by the phosphor layer 1 is high. It is possible to increase the green component strength.

Further, in the fluorescent lamp according to the fifth aspect of the present invention, the fluorescent lamp is a three-wavelength band emission type fluorescent lamp having a high luminous flux and a high color rendering property. It is possible to obtain a fluorescent lamp that does.

As described above, according to the present invention, the precipitation of sodium from the glass bulb 3 is suppressed, and the mercury that has permeated the phosphor layer 1 is prevented from reaching the surface of the glass bulb 3. Therefore, the glass bulb 3 is prevented. It is possible to suppress the coloring phenomenon. Further, since the ultraviolet rays with which the protective film 2 is irradiated are converted into visible light with high efficiency, the luminous flux of the fluorescent lamp 12 can be increased.

Further, the phosphor layer 1 is increased by the amount of the increased luminous flux.
The thickness can be reduced, and even if the material used for the phosphor layer 1 is reduced, it is possible to obtain a fluorescent lamp that emits a luminous flux equivalent to the conventional one. For this reason, even if a small amount of phosphor is newly used in the protective film 2, a fluorescent lamp that emits a luminous flux equivalent to the conventional one, but suppresses the luminous flux reduction that occurs with the passage of lighting time, is seen as a whole. It can also be provided at a low cost.

[0045]

EXAMPLE As an example of the present invention, the FCL30-
An EX-N / 28 fluorescent lamp was prototyped.

In the above prototype fluorescent lamp, the phosphor layer 1 is composed of (Ba, Sr) MgAl having a central particle diameter of 7.5 μm.
₁₀ O ₁₇ : Eu ²⁺ , Mn ²⁺ blue phosphor, central particle size is 4.5
The main component is a mixed phosphor powder of μm LaPO ₄ : Ce ³⁺ , Tb ³⁺ green phosphor and Y ₂ O ₃ : Eu ³⁺ red phosphor having a central particle size of 6.5 μm, and used as a binder. Ca-Ba-B-
It was constructed using a small amount of P-O compound. Further, the protective film 2 has a central particle diameter of 2.3 μm (Ba, Sr).
MgAl ₁₀ O ₁₇ : Eu ²⁺ , Mn ²⁺ blue phosphor and 0.04
Aluminum oxide (γ-Al ₂
O ₃ ), or Y ₂ O ₃ : Eu ³⁺ red phosphor having a center particle size of 2.1 μm and aluminum oxide (γ-Al ₂ O ₃ ) having a center particle size of 0.04 μm. Ca-Ba-B-P-O as a binder using a mixture of
Constructed with a small amount of compound.

Using these, a fluorescent lamp of the present invention was formed in which the thickness of the protective film and the thickness of the phosphor layer were changed, and the total luminous flux, the average color rendering index, and the luminous flux maintenance factor after 1000 hours were measured. did.

For comparison, the central particle size is 0.04 μm.
A conventional fluorescent lamp using a protective film of m of aluminum oxide alone was prepared and measured in the same manner as above.

The results are shown in Table 1.

[0050]

[Table 1]

As is clear from Table 1, the fluorescent lamp of the present invention showed higher total luminous flux and better luminous maintenance factor than the conventional fluorescent lamp. Further, the prototype fluorescent lamp No. 1 in which the coating amount of the fluorescent material is smaller than that of the conventional fluorescent lamp and the thickness of the fluorescent material layer is reduced by about 3%. Even in No. 3, since the total luminous flux equivalent to that in the conventional case is exhibited, it is possible to reduce the usage amount of the phosphor and to reduce the cost of the fluorescent lamp. In addition, in Table 1, the experimental results of a round electrode-type 30W-equivalent three-wavelength region emission type fluorescent lamp are shown, but similar effects can be obtained with other fluorescent lamps.

[0052]

As described above, the fluorescent lamp of the present invention includes small particles of a phosphor having a central particle diameter within the range of 1.0 μm <D ₅₀ ≦ 4.0 μm and 0.005 μm ≦ D.
_{Since the} protective film containing the fine particles of the metal oxide having the central particle diameter within the range of ₅₀ ≦ 1 μm is provided, it is possible to suppress the permeation of mercury and suppress the chemical reaction between mercury and sodium. Since the function of emitting fluorescence with high luminous efficiency can be added to the protective film, it is possible to provide a fluorescent lamp that achieves both high luminous flux and high luminous flux maintenance rate.

[Brief description of drawings]

FIG. 1 is a schematic sectional view of a main part of a fluorescent lamp of the present invention.

FIG. 2 is an enlarged view of part A of FIG.

[Explanation of symbols]

1 Phosphor layer 2 protective film 3 glass bulbs 4 Small particles of phosphor 5 metal oxides 6 Mercury vapor 7 rare gas 8 filament 9 mouthpiece 10 electrodes 11 stems 12 fluorescent lamp

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Claims (5)

[Claims] 1. A glass bulb having mercury and a rare gas enclosed therein has a function of generating electric discharge by applying electric power, a protective film is provided on an inner wall of the glass bulb, and fluorescent light is provided on the protective film. A fluorescent lamp having a phosphor layer mainly composed of a body, wherein the protective film has a central particle size (D ₅₀ ) of 1.
Small particles of the phosphor within the range of 0 μm <D ₅₀ ≦ 4.0 μm and the central particle size (D ₅₀ ) of 0.005 μm ≦ D ₅₀ ≦ 1 μ
A fluorescent lamp comprising metal oxide fine particles in the range of m. 2. The metal oxide is aluminum oxide,
The fluorescent lamp according to claim 1, which is at least one metal oxide selected from the group consisting of silicon oxide, titanium oxide, zinc oxide, and yttrium oxide. 3. The fluorescent lamp according to claim 1, wherein the fine particles of the metal oxide are fine particles of a phosphor. 4. The small particles of the phosphor are small particles of the phosphor mainly composed of at least a compound represented by any one of the following chemical formulas (1) to (3). Three
The fluorescent lamp according to any one of 1. _{(1) (Ba 1-ax} Sr a Eu x) (Mg 1-y Mn y) Al 10 O 17 (2) (Ba 1-abcx Sr a Ca b Mg c Eu x) 10 (PO 4) 6 Cl 2 (3) (Y _1-x Eu _x ) ₂ O ₃ However, x, y, a, b, and c are each 0.01 ≦ x ≦
0.3, 0 ≦ y ≦ 0.1, 0 ≦ a ≦ 1, 0 ≦ b <1, 0
It is a numerical value that satisfies ≦ c <1. 5. The fluorescent lamp according to claim 1, wherein the fluorescent lamp is a three-wavelength band emission type fluorescent lamp.