JP2005078926A - Fluorescent lamp - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a fluorescent lamp which is light in weight and superior in processing by making a material of a base used in the fluorescent lamp resin with high thermal conductivity, capable of preventing the deterioration of efficiency at a high temperature region by improving the heat radiation of the base. <P>SOLUTION: The fluorescent lamp 1 is composed of a bulb 2 in which electrodes 3 are provided at both ends so that one piece of a discharge path may be formed and a phosphor layer is formed on an inner face, and a discharge medium including mercury is filled, and a base 4 installed at the end 2c of the bulb made of a thermal conductive resin with a thermal conductivity of 10-30 W/m K. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a fluorescent lamp, and more particularly, to a fluorescent lamp having a base made of a highly thermally conductive resin.

  The annular fluorescent lamp can maintain the mercury vapor pressure in the bulb at an appropriate value and improve the luminous efficiency by controlling the temperature of the coldest part of the bulb as desired.

  Conventionally, the coldest part is formed near the end of the bulb, the exhaust pipe, or the central part of the light emitting part, etc., but these bases are manufactured by molding resin, so the lamp heat is formed inside the base. Because of the accumulation, there is a problem that the temperature in the appliance rises and the temperature of the coldest part rises.

Therefore, when the coldest part is formed in the base to solve this problem, a vent hole having a diameter of 2 to 3 mm is formed, and the exhaust pipe of the valve protrudes about 1 mm at the projected position of the vent hole. In this invention, the inside of the base is ventilated by the vent hole, and the end of the exhaust pipe or the valve is cooled to be the coldest part (see Patent Document 1) or the base is made of a highly heat conductive resin. There is known an invention (see Patent Document 2) in which a rise in the coldest part temperature can be suppressed by forming and further attaching a lamp socket formed of a resin having high thermal conductivity to the base and dissipating heat.
JP 2000-57938 A JP-A-11-167806

  However, in these inventions, a high thermal conductive resin has a thermal conductivity of less than 10 W / m · K, for example, about 1 to 4 W / m · K, and even when a vent is formed in the base. Since the heat is radiated only in a part of the holes and the base itself is formed of resin, the lamp heat is still trapped inside the base, which may affect the cooling efficiency. Thereby, in the conventional example, as the tube wall load increases, the coldest part temperature rises, and there is a problem that the luminous flux is particularly reduced in the appliance. As another means for improving the heat dissipation of the base, a metal base may be considered, but there is a problem that workability is inferior to that of resin.

  Therefore, the present invention is excellent in workability by making the base material used for the fluorescent lamp a resin having high thermal conductivity, and prevents the efficiency decrease in the high temperature region by improving the heat dissipation of the base part. An object of the present invention is to provide a fluorescent lamp that can be used.

  A fluorescent lamp according to claim 1, wherein an electrode is sealed at both ends so that one discharge path is formed, a phosphor layer is formed on the inner surface, and a discharge medium containing mercury is enclosed; A heat conductive resin having a thermal conductivity of 10 to 30 W / m · K is used as a material, and a base disposed at an end portion of the valve is provided.

  The shape of the valve is not particularly limited, such as a straight tubular valve, a circular valve such as a circle, a triangle, and a quadrangle.

  The tube inner diameter of the bulb can be in the range of 12 to 30 mm, preferably in the range of 12 to 20 mm. The optimum range of the inner diameter of the tube in consideration of lamp characteristics such as lamp efficiency and manufacturing conditions is 14-18 mm. Note that the wall thickness of the valve is preferably about 0.8 to 1.2 mm.

  In the present invention, the tube outer diameter of the straight tube portion is set to 30 mm or less including the fluorescent lamp that is widely used. However, it is known that the lamp efficiency of the fluorescent lamp is generally improved by reducing the tube diameter. In addition, it is preferable that the tube outer diameter of the straight tube portion is 20 mm or less because it is possible to achieve lamp efficiency equivalent to that of the small-diameter fluorescent lamp. On the other hand, if the tube outer diameter of the straight tube portion is less than 12 mm, it is difficult to ensure the mechanical strength as a glass bulb, and the light emission amount cannot be obtained sufficiently, which is not practical.

  In order to improve the lamp efficiency of a conventional annular fluorescent lamp (model name “FCL”) having a tube outer diameter of 29 mm by 10% or more, it is necessary to reduce the tube outer diameter to 65% or less. That is, the pipe outer diameter of the straight pipe part may be 18 mm or less. With this tube outer diameter, the fluorescent lamp can be sufficiently thinned. In consideration of characteristics such as the light emission amount and lamp efficiency, it is preferable that the tube outer diameter of the straight tube portion is 14 mm or more.

The phosphor layer is formed on the inner surface of the bulb and is composed of a phosphor and a binder that is a solvent for the phosphor. This phosphor layer preferably has an adhesion amount in the range of 3.5 to 8.0 mg / cm ² from the viewpoint of maintaining high luminous efficiency as a fluorescent lamp.

  The base is made of a thermally conductive resin having a thermal conductivity of 10 to 30 W / m · K, and is excellent in heat dissipation due to the high thermal conductivity. Therefore, when the fluorescent lamp is turned on, the temperature inside the bulb becomes high, but the heat conductivity of the die is high and heat is released from the die part, so that the temperature inside the bulb is prevented from rising and the temperature at the coldest part is the same. Therefore, the luminous efficiency can be kept high.

  The fluorescent lamp according to claim 2 is the fluorescent lamp according to claim 1, wherein the heat conductive resin is an alloy containing a heat conductive filler and at least two kinds of Cu, Al, Mg, Zn, Ag and Bi as a resin component. It is characterized by being a mixture of

  The present invention is a resin in which a heat conductive filler that has been conventionally used is mixed as a heat conductive resin, and a low melting point alloy is further mixed. Compared to a resin component that is a mixture of only a low melting point alloy, The thermal conductivity can be effectively increased.

  Examples of the resin component used here include resin components conventionally used as base materials, such as polybutylene terephthalate (PBT) and polyphenylene sulfide (PPS).

  In addition, as the thermally conductive filler used here, a thermally conductive filler conventionally used as a material to be included in a resin in order to enhance thermal conductivity such as aluminum powder / copper powder / boron nitride, aluminum nitride, alumina, etc. Can be mentioned.

  Moreover, examples of the low melting point alloy include solder and lead-free solder, and it is preferable to use lead-free solder in consideration of environmental influences. Lead-free solder is composed of two or more of silver (Ag), bismuth (Bi), magnesium (Mg), aluminum (Al), copper (Cu), zinc (Zn), tin (Sn), lithium (Li), etc. It is an alloy in which a metal is mixed. In particular, an aluminum-magnesium alloy is preferable because it increases the thermal conductivity of the resin and is easy to manufacture and handle.

  This heat conductive resin is a mixture of a heat conductive filler and a low melting point alloy in a resin material, and the die formed from this material has a network structure so that the low melting point alloy connects the heat conductive fillers to each other. Therefore, it is considered that the thermal conductivity is extremely good.

  According to a third aspect of the present invention, in the fluorescent lamp according to the second aspect, the bulb has an annular shape, and a base is disposed across both ends of the bulb.

  In the present invention, the bulb of the fluorescent lamp has an annular shape, and the shape thereof can be formed as a polygonal shape including a straight tube portion such as a circle, a triangle, or a quadrangle, and a bent portion.

  The annular valve is formed so that electrodes are sealed at the ends of the bulbs located on both sides, and the pair of ends are opposed to each other. Here, “a pair of end portions oppose each other” means that the valve shafts constituting the valve end portions are positioned on the same axis and the end surfaces of the valve end portions face each other. The end faces do not face each other but face each other, but the angle formed by the tube axes of the straight pipe portions constituting each valve end portion is, for example, approximately 90 °. May be opposed to each other.

  According to a fourth aspect of the present invention, in the fluorescent lamp according to any one of the first to third aspects, a large number of fins are provided so that the surface area of the outer surface of the base is enlarged.

  In the present invention, since a large number of fins are provided on the outer surface of the base, the surface area on the outer surface is large, and there are many portions in contact with the outside air. Since the base can release heat generated in the bulb by contacting with the outside air, the base used in the present invention is made of a high thermal conductive resin and further has fins. It is very excellent in heat dissipation. Examples of the shape of the base include a fin formed in the axial direction of the valve and a fin formed in a direction perpendicular to the valve axis.

  The fluorescent lamp according to claim 5 is the fluorescent lamp according to any one of claims 1 to 4, wherein the filament portion at one end of the electrode has a larger separation distance from the bulb end portion than the filament portion at the other end. The base on the valve end side that takes the mount structure and takes the high mount structure is formed of a heat conductive resin with a thermal conductivity of 10 to 30 W / m · K, and the opposite side has a thermal conductivity of 10 W / m · K. It is formed of the following resin.

  In the present invention, the luminous efficiency can be improved more effectively by the heat radiation of the cap portion, and the coldest part of the fluorescent lamp is formed at the bulb end. The end of the bulb closest to the base is suitable for reducing temperature changes when using a fluorescent lamp. By forming the coldest part here, the temperature of the coldest part can be easily controlled and stable lighting is achieved. be able to. In order to form the coldest part at the end of the bulb, a high mount structure in which one of the filaments of the pair of electrodes provided at the end of the bulb has a larger separation distance from the base than the filament at the other end Is achieved. At this time, the coldest part is formed at the valve end portion on the high mount side having a large separation distance from the base.

  Furthermore, in the fluorescent lamp having a high mount structure, the present invention provides a high heat conductive resin having a thermal conductivity of 10 to 30 W / m · K on the high mount side of the base, and a thermal conductivity of 10 W / m · on the opposite side. It is formed of a resin having a temperature of K or less, and is configured to more effectively suppress the temperature change in the coldest part.

  Since the fluorescent lamp of claim 1 is made of a thermally conductive resin having a high thermal conductivity of the base, it can prevent the temperature rise at the end of the glass tube and stably form the coldest part temperature, In particular, even in the thin tube bulb that has a high tube wall load and is easily affected by the coldest part temperature, the temperature rise can be effectively prevented, and the luminous efficiency of the fluorescent lamp can be improved. In addition, this effect becomes so large that the coldest part is near a nozzle | cap | die part, and it is remarkable when the coldest part exists in a valve | bulb edge part.

  In addition, since the base of the present invention is made of a resin, it is possible to provide an inexpensive base with high processability, light product mass, and low price.

  The fluorescent lamp of claim 2 shows a specific configuration that provides good thermal conductivity as a heat conductive resin. By using this heat conductive resin as a base material, The temperature rise of the portion can be more effectively prevented.

  The fluorescent lamp according to claim 3 is effective in increasing the temperature of the coldest part by using a base having good thermal conductivity even under the influence of heat from electrodes sealed at both ends of the annularly formed bulb. Can be prevented.

  The fluorescent lamp according to claim 4 is one in which fins are processed and formed in the base, and the surface area of the outer surface of the base is increased to improve heat dissipation, and the luminous performance is effectively improved by improving the cooling performance of the base part. Can be improved.

  The fluorescent lamp according to claim 5 stabilizes the temperature of the coldest part by using a resin having high thermal conductivity for the base of the bulb end portion having a high mount structure and using a resin having low thermal conductivity on the opposite side. Thus, the lighting of the fluorescent lamp can be stably performed and the luminous efficiency can be maintained high.

  Hereinafter, an embodiment of a fluorescent lamp of the present invention will be described with reference to the drawings. 1 and 2 show a first embodiment of the present invention, FIG. 1 is a plan view of a fluorescent lamp, and FIG. 2 is a front view and a side view of a base used in the fluorescent lamp of FIG.

  In FIG. 1, reference numeral 1 denotes a fluorescent lamp, which has a rectangular annular glass bulb 2 in which a straight portion forms a substantially square shape. The annular glass bulb 2 is filled with a discharge medium composed of a rare gas such as argon, neon or krypton and mercury. The rare gas in this embodiment is argon (Ar) gas, and the sealing pressure is about 320 Pa.

  The annular glass bulb 2 has five straight tube portions 2a and four bent portions 2b, and the five straight tube portions 2a are connected and arranged in the same plane so as to form a substantially square shape. . At this time, the length of one side of the glass bulb 2 is preferably 200 mm or more. In the present embodiment, the length of one side is about 300 mm. The straight pipe portion 2a preferably has a pipe outer diameter of 12 to 30 mm and a wall thickness of 0.8 to 1.5 mm. In this embodiment, the pipe inner diameter is about 14 mm and the wall thickness is about 1.2 mm. .

  The bulb 2 is preferably made of soft glass such as soda lime glass or lead glass, but may be made of hard glass such as borosilicate glass or quartz glass.

On the inner surface of the glass bulb 2, fine particles of a metal oxide such as alumina (Al ₂ O ₃ ) and silica (SiO ₂ ) or an alkaline earth metal phosphate such as strontium phosphate (Sr ₂ P ₂ O ₇ ) are used. As the fine particles, those having an average particle diameter of 10 nm to 10 μm can be used, and preferably 10 to 100 nm. When fine particles having an average particle size of 10 to 100 nm are used, the fine particles are difficult to sink into the glass when forming the bent portion, and the fine particles move together with the glass surface when bending the straight tubular bulb. It is possible to suppress the occurrence of cracks and peeling.

A phosphor layer is formed on the inner surface of the protective film. If troubles such as a luminous flux maintenance factor and film peeling during bulb processing do not become a problem, the inner surface of the bulb 2 is not provided with a protective film interposed. Although the phosphor layer can be formed directly, it is preferable to provide a protective film from the viewpoint of effectively preventing this problem. The coating amount of the protective film is 0.01~0.8mg / cm ^2, is preferably at least 0.1 mg / cm ² or more over the entire fluorescent lamp.

The phosphor layer is applied and formed on the inner surface of the straight tubular bulb before forming the bent portion. The phosphor constituting the phosphor layer can be a known phosphor such as a three-wavelength light-emitting phosphor or a halophosphate phosphor, and the three-wavelength light-emitting phosphor is preferably used from the viewpoint of light emission efficiency. As the phosphor of the three-wavelength emission type, BaMg ₂ Al ₁₆ O ₂₇ : Eu ²⁺ as a blue phosphor having an emission peak wavelength near 450 nm, and (La, Ce) as a green phosphor having an emission peak wavelength near 540 nm. , Tb) PO ₄ , Y ₂ O ₃ : Eu ³⁺ can be applied as a red phosphor having an emission peak wavelength near 610 nm, but is not limited thereto.

The adhesion amount per unit area of the phosphor layer is formed in the range of 3.5 to 8.0 mg / cm ² , and the film thickness at this time is about 15 to 30 μm. In the present embodiment, the phosphor layer is coated with phosphor fine particles having a three-wavelength emission type and a correlated color temperature of 5000 K, and the adhesion amount per unit area is 5.5 mg / cm ² through a drying and firing process. .

  Both ends 2c of the glass bulb 2 are arranged close to each other, and filament electrodes 3 and 3 made of a triple coil coated with an emitter material are respectively sealed at both ends 2c. The pair of electrodes 3 and 3 are supported by a pair of lead wires sealed to a flare stem (not shown), and the filament electrodes 3 and 3 are sealed in the bulb by sealing the flare stem to both ends 2c. The An exhaust thin tube 2d is attached to the flare stem, and an amalgam 2e is accommodated in the thin tube 2d.

  The amalgam 2e is sealed in the valve, and the position of the amalgam 2e is not limited to the exhaust thin tube 2d. For example, the amalgam 2e may be fixed to the welded portion of the flare stem. The amalgam is fixed or stored in any one of these positions by means such as melting and mechanical holding. Moreover, the amalgam may be accommodated so as to be movable in the bulb, and for example, the inner surface portion of the bulb 2 where the phosphor layer is formed may be enclosed so as to be movable.

  Amalgam is an alloy of mercury and a substance that forms an alloy with mercury, and may have any shape such as pellets, columns, and plates. For example, an amalgam such as zinc-mercury may be encapsulated for quantitative encapsulation of mercury. When an amalgam for controlling the mercury vapor pressure is disposed in the bulb, the optimum mercury vapor pressure is maintained even when the ambient temperature is relatively high, so that stable lighting can be performed. In addition, the amalgam 2e of this embodiment is the zinc amalgam for fixed quantity enclosure.

  The inside of the straight tube portion 2a is communicated via a bent portion 2b, and a single discharge path is formed between a pair of electrodes 3 and 3 so as to surround a substantially square center formed by the straight tube portion 2a. The

  As the pair of electrodes 3 and 3, a hot cathode electrode in which an emitter material is applied to a filament is applicable, but other electrodes may be used. When it is necessary to turn on the lamp at a high output, it is preferable to use a triple coil for the hot cathode electrode 3. The lead wire that supports the electrode 3 may be sealed and supported by a button stem, a bead stem, a pinch seal portion, or the like.

  In the fluorescent lamp 1, four bent portions 2b are formed at diagonal positions of a substantially square shape formed by the straight tube portion 2a of the glass bulb 2, and a base 4 is provided at both ends 2c of the pair of end portions 2c and 2c of the glass bulb 2. , 2c. The base 4 is provided with a base pin 5 which is a power feeding portion composed of four pins electrically connected to the pair of electrodes 3 and 3, and faces each other so that their tube axes are positioned substantially in the same line. It is spanned between the arranged both ends 2c, 2c, and is located at the approximate center of one side of the substantially square valve 2.

  A base pin 5 consisting of four pins of the base 4 is an electrical connection means for connecting to a power supply means such as a socket. This electrical connection means is provided at a position away from both end portions 2c and 2c of the valve. May be. Further, the base 4 may be configured to exhibit a function as a holding means by mechanical connection with a power feeding means such as a socket.

  The base 4 of the present invention is a mixture of a resin component, an alloy, and a thermally conductive filler to form a thermally conductive resin material. To mix these, powder mixing, solution mixing, and melt mixing are performed. Although it can be performed by a conventionally well-known method such as roll kneading, the thermal conductivity changes depending on the mixing method even if the heat conductive filler of the same capacity is used, so that the thermal conductivity can be made higher. From the standpoint of possible, it is preferable to use powder mixing.

  In this embodiment, polybutylene terephthalate resin is used as the base material, aluminum powder / copper powder / boron nitride is used as the heat conductive filler, and aluminum-magnesium alloy is mixed as the alloy to obtain a heat conductivity of 28.5 W / m · K. A heat conductive resin was produced, and a die was formed by extrusion molding using this resin.

  By the way, the thermal conductivity of about 0.1 to 0.4 W / m · K is used only with a resin such as polybutylene terephthalate that has been used in the past, and about 1 to 4 W / m · K even when the resin and the heat conductive filler are mixed. However, there was a limit to improving the heat dissipation of the base part.

  The thermal conductivity in the present invention is a disk having a diameter of 50 mm and a thickness of 10 mm as a test piece, the lower part of the test piece is maintained at a constant temperature, a heat sink is provided on the upper part, and heat is applied from the lower part to the upper part of the test piece. Was measured by a steady heat flow meter method in which the thermal conductivity was calculated from the temperature difference between the lower part and the upper part, the amount of heat flowing per hour, and the thickness of the test piece.

  In addition, since the base in the present invention uses a highly heat-conductive resin as the material, most of the base also has conductivity, and when the base and the base pin come into contact, a short circuit occurs. The portion where the base pin and the base come into contact is preferably made insulating.

  The base pin 5 is inclined by about 45 ° with respect to the plane formed by the bulb 2 and protrudes toward the center of the bulb 2 and rotates about ± 45 ° about the tube axis of the bulb ends 2c and 2c. Thus, it is attached to the valve end portions 2c and 2c together with the rotation restricting means. When the rotation restricting means exceeds a certain rotation angle, the base 4 side and the valve end 2c, 2c side relatively interfere with each other so that the rotation cannot be performed and the valve end 2c, This can be realized by providing protrusions at predetermined positions with respect to the outer surface of 2c, but the rotation restricting means is not limited to this.

  When the base 4 is configured to be rotatable beyond a predetermined angle, the outer lead wire connecting the base pin 5 and the electrode 3 is deformed by tension, and the outer lead wires come into contact with each other inside the base 4 and are short-circuited. Therefore, it is necessary to restrict the rotation to be less than a predetermined rotation angle.

  The bulb 2 may be configured such that the coldest portion is formed in at least one bent portion when the fluorescent lamp is turned on. The coldest part is formed at the lowest temperature part of the bulb when the fluorescent lamp 1 is lit, and the bent part may be formed so that the temperature does not easily rise during lighting. For example, there are a structure that forms a space away from the discharge path, a structure that has a larger surface area than other parts, and has an excellent heat dissipation effect.

  Further, it is possible to form the coldest part on the valve end 2c by separating the positions where the electrodes 3 and 3 are disposed from the valve end 2c by a predetermined length or more. For example, by setting at least one electrode height (the length from the bulb end to the electrode placement position) to be 30 mm or more, the coldest portion can be formed at a desired location on the bulb end. If it is possible to control the coldest part to the desired temperature, it is possible to ensure the optimum mercury vapor pressure without using an amalgam for mercury vapor pressure control even if the ambient temperature is high, and lamp efficiency Can be further improved.

  The bent portion 2b has a substantially circular tube-shaped cross-sectional shape that is substantially the same as the straight tube portion 2a. The bent portion 2b is formed so that the centers of the radii of curvature of the inner surface and the outer surface of the bent portion 2b are substantially at the same position.

  The glass bulb 2 used in the fluorescent lamp 1 of the present embodiment uses a straight tubular bulb having a phosphor layer formed on the inner surface, and has exhaust pipes 2d at both ends 2c and 2c, and a flare for introducing a pair of lead wires. After the electrodes 3 and 3 are mounted in the bulb via the stem, the bent portion formation scheduled portion is heated and softened with a gas burner, and the bending is performed so that the angle formed by the straight tube portions 2a is about 90 ° The first bent portion is formed in a predetermined shape by molding or the like, and this is repeated to form four bent portions, and then exhausted from the exhaust pipe 2d and enclosed with mercury.

  The fluorescent lamp 1 can have the following dimensions. The equivalent of a conventional 30 W type annular fluorescent lamp is formed such that the total length of the glass bulb 2 is 225 mm, the maximum inner width is 192 mm, the outer diameter of the tube is 16 mm, and the thickness of the glass bulb 2 is 1.0 mm. The fluorescent lamp is lit at a rated lamp power of 20 W and a lamp power of 27 W with high output characteristics. The conventional 32 W type annular fluorescent lamp has a glass bulb 2 with an overall length of 299 mm, an inner maximum width of 267 mm, a tube outer diameter of 16 mm, and a glass bulb 2 having a thickness of 1.0 mm. The fluorescent lamp is lit with a rated lamp power of 27 W and a lamp power of 38 W with high output characteristics. The equivalent of a conventional 40 W type annular fluorescent lamp is formed such that the total length of the glass bulb 2 is 373 mm, the maximum inner width is 341 mm, the outer diameter of the tube is 16 mm, and the thickness of the glass bulb 2 is 1.0 mm. The fluorescent lamp is lit at a rated lamp power of 34 W and a lamp power of 48 W with high output characteristics.

  In the fluorescent lamp having such high output characteristics, since the heat generation amount increases as the value of the tube wall load increases, the temperature inside the bulb increases and the coldest part temperature is affected. The effect is remarkable in the fluorescent lamp having high output characteristics.

In the fluorescent lamp 1 of the present embodiment, the tube outer diameter of the straight tube portion 2a is 12 to 20 mm, and the amount of ultraviolet light irradiated on the tube inner surface tends to increase. ˜8.0 mg / cm ² . If the coating amount is less than 3.5 mg / cm ² , the light emission amount cannot be sufficiently obtained, and the improvement in the light emission amount is remarkable when the adhesion amount of the phosphor fine particles is 6.5 to 7.5 mg / cm ^2. An effect is obtained. Moreover, when the adhesion amount of the phosphor fine particles exceeds 8.0 mg / cm ² , the effect of improving the light emission amount by increasing the thickness of the phosphor layer does not appear remarkably.

Next, the operation of this embodiment will be described. The fluorescent lamp 1 receives high frequency power from the base 6 and is turned on by low pressure mercury vapor discharge in the bulb 2. The fluorescent lamp 1 is lit so that the lamp input power is 20 W or more, the lamp current is 200 mA or more, the tube wall load is 0.05 W / cm ² or more, and the lamp efficiency is 501 m / W or more. The lamp current density, which is the lamp current per cross-sectional area of the straight pipe portion 2a, is 75 mA / cm ² or more. In this embodiment, the lamp input power is 50 W, the lamp current is 380 mA, and the lamp efficiency is 901 m / W.

  In the case of this embodiment, the glass bulb 2 is formed by locally bending one straight tubular bulb. However, the glass bulb 2 is composed of two L-shaped bulbs. The glass bulb 2 may be configured by connecting the end portions to form one bent portion.

By the way, the glass bulb 2 can be used with substantially no lead component, a sodium oxide content of 1.0 mass% or less, and a softening temperature of 720 ° C. or less. Here, “substantially free of lead component” means that it may be contained as long as it is an impurity, and preferably 0.1% by mass or less. Of course, the most preferable glass is one containing no lead component. The content of sodium oxide of 0.1% by mass or less includes the case where sodium oxide is not contained in the glass. The reason why the content of sodium oxide is defined as 0.1% by mass or less is that when the above value is exceeded, the amount of light emitted from the fluorescent lamp 1 is affected by the sodium component deposited on the inner surface of the glass bulb 2. As a glass having a composition containing substantially no lead, a sodium oxide content of 1.0% by mass or less, and a softening temperature of 720 ° C. or less, the contents of K ₂ O and Li ₂ O and CaO, MgO, It can be obtained by adjusting the content of BaO and SrO. Here, the softening temperature is a temperature at which the glass has a viscosity η = 107.65 dPa · s.

  When sodium oxide exceeds 0.1% by mass on the glass bulb 2, a large amount of sodium is deposited on the inner surface of the glass bulb 2 as an alkaline component during lighting. When this sodium is deposited on the inner surface of the glass bulb 2, the sodium and mercury vapor sealed in the glass bulb 2 react to color the glass bulb 2 to reduce the visible light transmittance, or sodium is a phosphor. The phosphor material reacts with the phosphor material in the layer to cause a problem that the output of visible light is reduced. In particular, the conventional soda lime glass contains 15 to 17% by mass of sodium oxide, so that the output reduction of visible light is remarkable.

  Therefore, when a phosphor is applied to a straight tubular bulb made of glass having a sodium oxide content of 0.1% by mass or less and a softening temperature of 720 ° C. or less, for example, 692 ° C., and then forming a bent portion, The amount of sodium that precipitates is extremely small, and the decrease in the amount of visible light emitted by the reaction of sodium is suppressed. Further, since the softening temperature is 720 ° C. or lower, the heating temperature at the time of forming the bent portion is kept low, the thermal deterioration of the surrounding phosphor is reduced, and the light emission amount is improved.

  FIG. 3 is a front view and a side view of the base 3 of the fluorescent lamp that is the second embodiment of the present invention. A fin 6 is formed on the outer surface of the base 3 along the axial direction of the bulb to increase the surface area, and the fin 6 has a triangular cross section. Except for the shape of the base, it is the same as the first embodiment.

  FIG. 4 is a front view and a side view of the base 3 of the fluorescent lamp that is the third embodiment of the present invention. On the outer surface of the base, fins 6 are formed in a direction perpendicular to the axis of the bulb to increase the surface area, and the fin has a square cross section. Except for the shape of the base, it is the same as the first embodiment.

  In the second and third embodiments, the surface area of the outer surface of the base 3 is enlarged, and it is easier to dissipate heat compared to a base having a shape that is normally used, so that the rise in the coldest part temperature is further suppressed. Therefore, a stable light emission amount can be obtained.

  FIG. 5 is a front view and a side view of a base 3 of a fluorescent lamp that is a fourth embodiment of the present invention. FIG. 5 shows a fluorescent lamp having a high mount structure, in which the base 8 on the high mount side is made of a high thermal conductive resin having a thermal conductivity of 10 to 30 W / m · K, and the base 9 on the other end has a thermal conductivity. It is integrally molded from a resin of 10 W / m · K or less. In this way, by using materials having different thermal conductivities as the base material, the heat from the electrode on the other end side is conducted from the base 9 to the base 8 by making the coldest part side a material having high thermal conductivity. Since the heat dissipation efficiency of the base 8 on the high mount side, which is difficult to be affected by heat, is improved, the coldest part temperature is stabilized, and the luminous efficiency of the fluorescent lamp can be optimized.

  Thus, when making a die using resins having different thermal conductivities, if the same resin component or a resin component that can be integrally molded is used, the die is partially molded first using one resin. Before the resin is completely cured, the base can be integrally formed by continuously molding the remaining part of the base using the other resin. In addition, when it is not integrally molded or when it is difficult to integrally mold because of different resin components, each base part is molded separately and can be connected to each other by forming a claw at the coupling position. You can also keep it.

  Regarding the fluorescent lamp of the first embodiment and the fluorescent lamp of the fourth embodiment, when the temperature of the coldest part after these fluorescent lamps were continuously lit for 1 hour was measured, in the first embodiment, 43 ° C., In the fourth embodiment, the temperature was 40 ° C.

  As a comparison, a fluorescent lamp having a base molded using a conventional heat conductive resin in which aluminum powder / copper powder / boron nitride is mixed as a heat conductive filler with polybutylene terephthalate was measured in the same manner. The cold part temperature was 50 ° C., and it was found that the fluorescent lamp of the present invention can effectively suppress the rise of the coldest part temperature, and thereby the light emission amount can be secured stably.

It is a top view of the fluorescent lamp showing the 1st embodiment of the present invention. It is the front view and side view of a nozzle | cap | die of the fluorescent lamp shown in FIG. It is the figure which showed the nozzle | cap | die of the fluorescent lamp which is 2nd Embodiment. It is the figure which showed the nozzle | cap | die of the fluorescent lamp which is 3rd Embodiment. It is the figure which showed the nozzle | cap | die of the fluorescent lamp which is 4th Embodiment.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Fluorescent lamp, 2 ... Glass bulb, 2a ... Straight pipe part, 2b ... Bending part, 2c ... End part, 3 ... Electrode, 4 ... Base, 5 ... Base pin, 6 ... Fin, 7 ... Coldest part

Claims (5)

A bulb in which electrodes are sealed at both ends so that one discharge path is formed, a phosphor layer is formed on the inner surface, and a discharge medium containing mercury is enclosed;
A base made of a thermally conductive resin having a thermal conductivity of 10 to 30 W / m · K and disposed at an end of the valve;
A fluorescent lamp characterized by comprising:   2. The heat conductive resin according to claim 1, wherein the heat conductive resin is a resin component mixed with a heat conductive filler and an alloy containing at least two of Cu, Al, Mg, Zn, Ag and Bi. Fluorescent lamp.   The fluorescent lamp according to claim 1 or 2, wherein the bulb is annular, and a base is disposed across both ends of the bulb.   The fluorescent lamp according to any one of claims 1 to 3, wherein a large number of fins are provided so that a surface area of an outer surface of the base is enlarged.   The filament part at one end of the electrode has a high mount structure in which the separation distance from the valve end part is larger than the filament part at the other end, and the valve end side taking the high mount structure of the base has a thermal conductivity of 10 to 30 W / The fluorescent lamp according to any one of claims 1 to 4, wherein the fluorescent lamp is made of a heat conductive resin of m · K, and the opposite side is made of a resin having a heat conductivity of 10 W / m · K or less.

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