JP2003045374A - Fluorescent lamp - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a fluorescent lamp of which, a joint part jointing a straight tube bulb and a jointing tube is prevented from a generation of crack in advance. SOLUTION: For the fluorescent lamp using a phosphor emitting light of three wave length of red, green, and blue, as a phosphor layer 2 formed to the inner surface of a folded bulb composed of a discharge path formed by connecting one end side of a plurality of straight tube bulbs 1a, having a length of more than 1,000 mm, with a connecting tube 1b respectively, having respective electrodes at the other end side of the straight bulb tube, the blue color phosphor is composed by mixing a first blue color phosphor containing europium activated aluminate of alkali earth metal as a main component, and a second blue color phosphor containing europium activated chlorophosphate of alkali earth metal as a main component.

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 a bending bulb in which two straight bulbs are connected by a connecting pipe.

[0002]

2. Description of the Related Art Conventionally, this type of fluorescent lamp has been disclosed in Japanese Patent Laid-Open No.
A high output type is known as described in Japanese Patent Application Laid-Open No. 0-302719. This prior art fluorescent lamp is called model name FHP105, and model name FPR9.
Since it has a smaller tube diameter and a longer discharge path than the fluorescent lamp of No. 6, it is a fluorescent lamp of high efficiency and high light output.

[0003]

DISCLOSURE OF THE INVENTION Prior art fluorescent lamps
Is two straight pipe valves with a total length of 1000 mm or more arranged in parallel
Connected, connect the tip of one side with a connecting pipe,
An electrode is sealed at each end to form a single discharge path.
It is a thing. This straight tube bulb has a phosphor layer on the inner surface
After that, the straight pipe valve is connected by a communication pipe. This
Here, a three-wavelength type phosphor is used for the phosphor layer.
It For example, red is europium activated oxide
Lithium phosphor (Y_TwoO_Three: Eu⁺³), As green
Lanthanum phosphate phosphor activated with um and terbium ((La,
Ce, Tb) PO_Four), Europium activated
Lucari earth metal chlorophosphate phosphor ((Sr, Ca,
Ba) ₅(PO_Four)_ThreeCl: Eu) was used.

In the case of connecting two straight pipe valves, first, the vicinity of the end of the straight pipe valve to be connected is heated and softened by a burner, and one end is separated by further heating and softening the ends. Block the area. Next, if the burner is locally heated with a burner while pressurizing the inside of the pipe from the other open end of the straight pipe valve, the heated portion is softened and blown off. In this manner, the communication pipe connecting the two straight pipe valves is formed by heating and joining the periphery of the blowout with a burner.

There is an exhausting step of discharging the air in the U-shaped valve to the outside after forming a substantially U-shaped valve by connecting such straight pipe valves with a connecting pipe. In the temperature rising process of this exhaust process, due to the temperature difference inside and outside the valve,
Since the other ends of the two straight pipe valves are opened so as to form a C shape so as to be separated from each other, there is a problem that a crack is generated at a connecting portion between the straight pipe valve and the connecting pipe. there were.

The present invention has been made in view of the above points, and an object thereof is to provide a fluorescent lamp capable of preventing the occurrence of cracks at the connecting portion between a straight tube bulb and a connecting tube. is there.

[0007]

According to a first aspect of the present invention, there is provided a fluorescent lamp in which a plurality of straight tube bulbs each having a total length of 1000 mm or more are connected at one end side to each other by a connecting tube to form a folded and bent discharge path. In a fluorescent lamp using a three-wavelength light emitting phosphor of red, green and blue phosphors as a phosphor layer formed on the inner surface side of a bent bulb in which electrodes are respectively sealed at the other ends of the straight tube bulbs, the blue There are two types of phosphors, a first blue phosphor mainly composed of europium-activated alkaline earth metal aluminate and a second blue phosphor mainly composed of europium-activated alkaline earth metal chlorophosphate. It is characterized by being mixed.

In the present invention and the following inventions, the definitions and technical meanings of terms are as follows unless otherwise specified.

As the electrode, a filament coil as a hot cathode is usually used, but it is not particularly limited to the hot cathode due to the nature of the invention. However, it is preferable to use a hot cathode in a fluorescent lamp that performs high output lighting. The hot cathode is formed by applying an electron emitting material to a filament connected between the leading ends of the lead wires. The lead-in wire is usually sealed to the flare stem. The flare stem is sealed to the other end of the straight tube valve, which is the outermost end of the discharge path, to hermetically seal the bent valve.

The straight pipe valve has an outer diameter of 12 to 18 mm. If the outer diameter is less than 12 mm, the luminous efficiency at 45 ° C., which is the normal operating temperature range of the high-power fluorescent lamp, decreases, which is not practical.

The straight pipe valve and the communicating pipe are usually made of glass pipes. The glass may be made of any material. However, although soft glass is preferable in terms of economy and workability, other glasses such as hard glass and quartz glass can be used if necessary. Furthermore, the present invention does not exclude the use of materials other than glass. As the soft glass, soda lime glass, lead glass, or so-called lead-free glass can be used.

The method of forming a discharge path by connecting straight pipe valves with a communicating pipe is as follows. That is, the end portion is closed by heating and softening the vicinity of the side portion on the side to be connected of the straight pipe valve with a burner and further separating the end portion while further heating. Next, while heating the inside of the pipe from the opposite open end of the straight pipe valve, locally heating the burner by locally moving the planned connection point in the pipe axial direction with the burner, the heated portion softens. Then blown away. A communicating pipe that connects two straight pipe valves by discussing the blowout parts of the two straight pipe valves in which the blowout has been formed in this way, and heating and joining the periphery of the blowout parts with a burner. To form.

In the coldest part of the bent bulb, the communication pipe is formed at a position offset by 10 mm or more from the end of the straight pipe valve toward the center side, so that a positive column of discharge is formed at the end of the straight pipe valve. A non-discharge region that is not formed is formed, and thus the coldest part can be formed. In this case, the end face of the straight pipe valve is based on the end face on one end side of the straight pipe valve.

The discharge body is mercury and a rare gas, and argon, neon or the like can be used as the rare gas. Mercury is recommended to be encapsulated in the form of zinc-mercury amalgam, which has temperature-vapor pressure characteristics similar to pure silver. The fluorescent lamp according to claim 2 is the first lamp according to claim 1.
The weight ratio of the blue phosphor to the entire blue phosphor is 1
It is characterized by being 0% to 40%.

The fluorescent run according to claim 3 is characterized in that the tube wall load of the bending valve according to claim 1 or 2 is 0.07 W / cm ² or more.

[0016]

DETAILED DESCRIPTION OF THE INVENTION A first embodiment of the present invention will be described below with reference to the drawings. In FIG. 1, 1 is a bending bulb, 2 is a phosphor layer, 3 is an electrode, 4 is a base, and 5 is a spacer. The bending valve 1 is a pair of straight pipe valves 1.
Both ends of a U-shaped bent and bent discharge path composed of a and the communication tube 1b are sealed by a pair of flare stems.

The straight pipe valve 1a has an outer diameter D of 17.5 mm,
It consists of a soda-lime glass tube with a wall thickness of 1.1 mm and a length of 1150 mm. Therefore, the inner diameter of the straight pipe valve 1a is about 1
It is 5.3 mm.

The communication pipe 1b is one end portion 1 of the straight pipe valve 1a.
It was formed by blowing so that the inner surface on the one end 1c side of the communicating tube 1b was located at a position where the distance 1 from the inner surface of c was 5 mm.

The space from the communicating pipe 1b to the one end 1c acts as a non-discharging portion 1d, and the internal volume of the non-discharging portion 1d is about 1 cm ³ for one straight pipe valve 1a. Then, on the inner surface of the straight tube bulb 1a, a protective film made of alumina fine particles and a phosphor layer 2 of a three-wavelength light emission type were overlapped and formed.

As the three-wavelength type phosphor layer 2, red
Europium activated yttrium oxide fluorescent as color phosphor
Body (Y_TwoO_Three: Eu⁺³), As a green phosphor
, Terbium-activated lanthanum phosphate phosphor ((La, C
e, Tb) PO_Four), With europium as a blue phosphor
Active barium-magnesium aluminate phosphor (BaMg
_TwoAl₁₆O₂₇: Eu²⁺) (Hereinafter referred to as BAM
) And europium activated strontium calcium calcium
Barium chlorophosphate phosphor (SrCaBa)
₅(PO_Four)_ThreeCl: Eu (hereinafter referred to as apatite
2).

In the communication pipe 1b, the width d1 in the longitudinal direction of the straight pipe valve 1a is 20 mm, and the width d2 in the direction orthogonal to the juxtaposed direction of the straight pipe valves 1a is 13.4 mm.

The electrode 3 is attached to the flare stem. The discharge path length of the bending bulb 1 is 2100 mm.

Mercury and argon gas 2.4 as discharge medium
torr and is enclosed. Mercury is zinc amalgam (Z
n-Hg) and is enclosed in the form of a mercury pellet p. This mercury pellet p is enclosed in a thin tube 1f provided on the flare stem on the other end of the straight tube valve 1a.

The mercury pellet p is enclosed at a position in the thin tube 1f which is separated from the electrode 3 by 40 mm or more, and is arranged inside the base 4. In this way, the mercury pellets p are enclosed and arranged inside the base 4. By enclosing the mercury pellets p in this way, it is possible to suppress a decrease in luminous efficiency during lamp lighting in a low temperature atmosphere, and it is possible to efficiently light a wide range. Also,
Since it is not sealed with pure water silver, it is possible to suppress the aggregation and stickiness of mercury in the low temperature region of the bulb.

The amount of mercury distributed when the light was turned off in the inner region of the straight pipe valve 1a within 220 mm from the inner surface of the one end 1c of the straight pipe valve 1a was 0.09 mg.

Two blue phosphors, BAM and apatite
The reason why only types are mixed will be described.

The straight pipe valve 1a has an outer diameter D of 17.5 mm,
It is a soda-lime glass tube having a wall thickness of 1.1 mm and a length of 1150 mm, and the distance between the two straight tube valves 1a is 2.5 mm.

Experiments were carried out on the yield and the initial luminous flux by variously changing the BAM mixing ratio (% by weight) in the blue phosphor.
FIG. 3 is a yield and luminous flux maintenance factor, FIG. 4 is a characteristic diagram of initial luminous flux,
FIG. 5 is a graph showing the light speed maintenance rate when 2000 hours have passed after the start of lighting. Since the blue phosphor is composed only of BAM and apatite, (100-BAM mixing ratio)
Is the mixing ratio of apatite.

As is clear from FIG. 3, when the BAM mixing ratio is smaller than 10%, the yield is suddenly reduced.
It is not clear why this yield changes when the mixing rate is changed, but stress is applied to the connecting tube due to the difference in the coefficient of thermal expansion between the glass of the bulb and the phosphor layer when heated during exhaust. It is presumed that this is because

When the tube wall load on the fluorescent lamp according to the present invention is 0.07 (W / cm ² ) or more, BA
It is shown in FIG. 5 that the MAM mixing ratio is changed to 80% at 2000 hours when the BAM mixing ratio is smaller than 40%. Here, the tube wall load indicates the input power / surface area inside the bulb, and when the tube wall load exceeds a certain level, short ultraviolet rays increase, so that the phosphor is damaged more.

Therefore, the mixing ratio of BAM is 10% to 40%.
Thus, both the yield and the luminous flux maintenance factor can be satisfied. Furthermore, the mixing ratio of BAM is 10% to 4
The initial luminous flux of 0% has a certain value as shown in FIG. As a result, regarding yield and initial luminous flux, BAM
Is better than apatite, and apatite is better than BAM in terms of luminous flux maintenance factor.

By the way, the planned connection point a while pressurizing the inside of the pipe from the open end of the straight pipe valve 1a.
When locally heated with a burner, the heated portion is softened and blown off. In this way, the communication pipe 1b for connecting the two straight pipe valves 1a can be formed by heating and joining the periphery of the blowout with a burner.
At this time, as shown in FIG. 6, the upper two burners 11, 1
The connecting pipe 1b is formed by blowing while moving the two and the lower two burners 13, 14 in opposite directions along the pipe axis direction. Note that FIG. 6A is a side view and FIG. 6B is a plan view. By doing so, it is possible to reduce the occurrence of buildup of meat at the side end of the straight pipe valve 1a of the connecting pipe 1b.

Further, as shown in FIG.
The book burners 21 and 22 may be moved in opposite directions along the pipe axis direction of the straight pipe valve 1a. 7A is a side view and FIG. 7B is a plan view.

FIG. 8 shows the positions of the side ends of the connecting pipe 1b and the straight pipe valve 1a and the relative values (%) of the wall thickness. That is,
The relative value of the wall thickness with respect to the wall thickness at the 0 position is shown. Here, the position means the connecting pipe 1b as shown in FIG.
And the half of one side of the elliptical portion which is the side end of the straight pipe valve 1a is divided into eight parts. The black triangle is fixed to the burner as in the past, and only the specific part is heated to connect the communication pipe 1b.
The relative value of the wall thickness in the case of forming the above, the black circle indicates the relative value of the wall thickness in the case where the connecting pipe 1b is formed by blown away while the burner is relatively moved along the pipe axis direction. That is, the thickness of the connecting pipe 1b and the side end portions of the straight pipe valve 1a should be kept constant when the connecting pipe 1b is formed by blowing while the burner is relatively moved along the pipe axis direction. Can understand.

[0035]

According to the invention of claim 1, the total length is 10
One end of each of the straight pipe valves of 00 mm or more is connected to each other by a connecting pipe to form a folded and bent discharge path, and the other end of the straight pipe valve has an electrode sealed on the inner surface side of the bent bulb. In a fluorescent lamp using a three-wavelength light-emitting phosphor of red, green, and blue phosphors as the formed phosphor layer, the blue phosphor has a first component containing europium-activated alkaline earth metal aluminate as a main component.
The two types of the blue phosphor of No. 2 and the second blue phosphor having europium-activated alkaline earth metal chlorophosphate as a main component are mixed, so that the connecting portion between the straight pipe valve and the connecting pipe is It is possible to prevent cracks from occurring.

According to the second aspect of the present invention, the weight ratio of the first blue phosphor to the entire blue phosphor is 10% to 10%.
By setting it to 40%, it is possible to obtain the effect of the first aspect and to improve both the yield and the luminous flux maintenance factor.

According to the invention of claim 3, in addition to the effect of claim 1, the luminous flux maintenance factor can be maintained.

[Brief description of drawings]

FIG. 1 is a front view of a fluorescent lamp according to an embodiment of the present invention.

FIG. 2A is a partially enlarged front view showing one end side of the fluorescent lamp, and FIG. 2B is a side view of the same.

FIG. 3 is a diagram showing a relationship between a BAM mixing ratio and a yield.

FIG. 4 is a diagram showing a relationship between an initial luminous flux and a BAM mixing rate.

FIG. 5 is a diagram showing a relationship between a luminous flux maintenance factor and a BAM mixing ratio.

FIG. 6 is a diagram for explaining a method of forming a connecting pipe.

FIG. 7 is a diagram for explaining a method of forming a connecting pipe.

FIG. 8A is a diagram showing a relationship between a position and a relative value,
(B) is a figure for explaining a position.

[Explanation of symbols]

1 ... Flexible valve, 1a ... Straight pipe valve, 1b ... communication pipe, 1c ... One end, 2 ... Phosphor layer, 3 ... electrode, 4 ... Clasp.

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Hitoshi Imamura             4-3-1, Higashishinagawa, Shinagawa-ku, Tokyo Toshiba             Inside Litec Co., Ltd. F-term (reference) 4H001 CA05 CA06 XA08 XA12 XA13                       XA15 XA17 XA20 XA38 XA56                       YA63                 5C043 AA14 CC09 CD10 DD28 EB04                       EC06 EC16

Claims (3)

[Claims] 1. A plurality of straight pipe bulbs each having a total length of 1000 mm or more are connected at one end side to each other by a connecting pipe to form a discharge path bent back and bent, and electrodes are respectively sealed at the other end portions of the straight pipe bulbs. The red, green, and blue phosphors are used as the phosphor layer formed on the inner surface side of the bent bulb.
In a fluorescent lamp using a wavelength emission phosphor, the blue phosphor includes a first blue phosphor mainly composed of europium-activated alkaline earth metal aluminate and a europium-activated alkaline earth metal chlorophosphate. A fluorescent lamp in which two kinds of second blue phosphors as main components are mixed. 2. The fluorescent lamp according to claim 1, wherein the weight ratio of the first blue phosphor to the entire blue phosphor is 10% to 40%. 3. The wall load of the bending valve is 0.07 W.
/ Cm ² or more, claim 1 or 2 characterized by
The fluorescent lamp according to any one of the above.