JP4775642B2 - Fluorescent lamp and lighting device - Google Patents

Description

  The present invention relates to a fluorescent lamp suitable for curve-forming by heating and softening a glass bulb after forming a phosphor layer, and an illumination device including the same.

  Known as fluorescent lamps for general lighting, straight-tube, ring-shaped, or single-piece-type fluorescent lamps are known, and in particular, based on recent demands for energy and resource saving, small-diameter ring-shaped fluorescent lamps dedicated to high-frequency lighting have been developed. Have been commercialized (see Patent Document 1). This small-diameter annular fluorescent lamp is identified by the model name “FHC” on the commodity. This small-sized annular fluorescent lamp has the same outer diameter as the conventional annular fluorescent lamp, but the outer diameter of the tube is small, and it is possible to ensure the same or higher lamp efficiency or brightness. It is possible to satisfy the needs of energy saving and resource saving, and to make the visual environment particularly comfortable in the living space.

  On the other hand, a rectangular fluorescent lamp has been known (see Patent Document 2). The fluorescent lamp described in Patent Document 2 is a bulb having a tube outer diameter of 25 to 32 mm, a radius of curvature inside the bent portion of 20 to 40 mm, and an outer dimension between opposing linear portions of 190 to 220 mm. It is the 30W type square fluorescent lamp used. Further, a rectangular fluorescent lamp having a 32 W type in which an outer dimension between opposing linear portions is 260 to 290 mm is also known.

By the way, when forming the phosphor layer on the inner surface of the fluorescent lamp, a protective film is formed in advance, and by forming the phosphor layer on the inner surface of the protective film, it is possible to suppress blackening of the glass due to mercury implantation. it can. In general, the protective film is formed by applying and drying a coating solution of fine particles such as γ-Al ₂ O _{3 on} the inner surface of the glass bulb and then heating and baking the glass bulb. Further, in the case of a fluorescent lamp having a curved shape, regarding the front and back relationship between the forming process of the protective film and the phosphor layer and the molding process of the glass bulb, the protective film and the phosphor layer are formed before the glass bulb is molded as described above. There is an aspect in which the film is formed and an aspect in which the film is formed after molding. However, in the case of fluorescent lamps having a small diameter and a square shape, the former is more suitable for mass production.

Also, a technique is known in which strontium phosphate (Sr ₂ P ₂ O ₇ ) particles having a relatively large particle size are used as a protective film material for the purpose of reducing the amount of phosphor used in a fluorescent lamp (see Patent Document 3). ).

Japanese Patent No. 3055769 (pages 3-9, FIG. 3) JP 58-152365 A (2nd page, Fig. 2) JP 2004-006185 A (pages 11-13, FIG. 7)

  However, if a fluorescent lamp having a curved portion with a small radius of curvature such as a corner portion in a rectangular shape or the like having a small diameter is manufactured based on the prior art, the fluorescent layer is easily cracked or peeled off at the curved portion. It turned out that there was a problem that the appearance of the. According to the inventor's investigation, when the glass bulb is heated and softened, it is presumed that the protective film does not expand or contract even if the glass in the curved portion expands or contracts. The In addition, regarding the protective film shown in Patent Document 3, the relationship between the crack of the phosphor layer that occurs when the curved portion is formed and the structure of the protective film has not been sufficiently studied.

  The present invention has a configuration in which a glass bulb is curved after forming a phosphor layer, and the phosphor layer is hardly cracked or peeled even in a curved portion having a small radius of curvature, and thus has a fluorescent lamp having a good appearance and the same. An object is to provide a lighting device.

The fluorescent lamp of the present invention includes a glass bulb having a curved portion; a fine particle layer formed of fine particles having an average particle diameter of 100 nm or less and attached to the inner surface of the glass bulb; and a part of the fine particle layer having an average particle diameter of 1 μm or more A protective film having large-diameter particles buried therein, and the remainder protruding from the fine particle layer; a phosphor layer formed on the protective film of the glass bulb; a discharge medium sealed inside the glass bulb; and glass A discharge generating means for generating a discharge inside the bulb.

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

  <Regarding Glass Bulb> The glass bulb is composed mainly of a glass tube, and allows a curved portion having a small radius of curvature (hereinafter referred to as a “bent portion” for convenience). As an example of such a glass bulb, it is possible to employ a configuration that includes one or a plurality of bent portions and a straight pipe portion, and has a substantially closed shape as a whole. Specifically, for example, a quadrangle, a deformed ring in which a D-shaped part faces the linear part apart from each other in parallel, or a single discharge path while these shape parts are further multiplexed. It is allowed to have various shapes such as a contacted shape so as to form.

  Since the tube length of the glass tube is not particularly limited, it can be set to an appropriate tube length as desired.

  When the glass bulb has a bent portion, the bent portion can be formed by the following method. That is, after forming a protective film and a phosphor layer, which will be described later, on the inner surface of a single straight glass tube, a glass bulb is formed by sealing a pair of electrodes at both ends of the glass tube. Further, only the bent portion of the glass bulb can be formed by locally heating and bending. The length of the bent portion can be configured to be in the range of 15 to 50% of the central axis length of the glass bulb. Further, the inner radius of curvature at the bent portion is allowed to be not more than 3 times, preferably not more than 2 times the outer diameter of the glass tube. Furthermore, the bent portion is not limited to a simple bent glass tube, and if necessary, it is allowed to perform shaping by performing molding using a mold after bending. The single straight tubular glass tube may be one when in a raw tube state, or a single glass tube may be obtained by joining a plurality of straight tubular glass tubes. . In the latter case, the ends of the glass base tubes can be joined after the glass base tubes are bent before joining the plurality of glass base tubes.

  Further, the glass bulb is allowed to include one or a plurality of straight pipe portions in addition to the bent portion described above. In this case, the straight tube portion can have an inner diameter in the range of 12 to 20 mm, but the optimum range when considering lamp characteristics such as lamp efficiency and manufacturing conditions is 14 to 18 mm. . Even in the case of the straight pipe portion, the portion in the vicinity of the bent portion is allowed to partially change from the above range due to a slight change in the outer diameter of the tube when the bent portion is formed. The thickness of the glass bulb is preferably about 0.8 to 1.2 mm in a straight pipe portion or a gentle curved portion with a large curvature.

  Although it is known that the lamp efficiency is improved by reducing the tube diameter of the fluorescent lamp, the tube outer diameter can be set to 20 mm or less, preferably in a straight tube portion or a gently curved portion. If the outer diameter of the tube is 20 mm or less, it is possible to achieve a lamp efficiency equal to or higher than that of the conventional small-diameter annular fluorescent lamp. On the other hand, when the tube outer diameter is less than 12 mm, it becomes difficult to ensure the mechanical strength as a glass bulb having a bent portion, and the light output is equivalent to that of a conventional annular fluorescent lamp of the same size. Is not practical because it cannot be obtained.

  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 outer diameter of the glass bulb may be 18 mm or less. With this tube outer diameter, the fluorescent lamp can be sufficiently thinned. In consideration of characteristics such as light output and lamp efficiency, the outer diameter of the straight pipe portion is preferably 14 mm or more.

  In the case of a glass bulb having a polygonal shape which is a preferred shape in the present invention, there are three or more straight pipe portions. In addition, the bent part connecting the straight pipe parts is formed so as to be one less than the straight pipe part in the case of a shape in which both ends of the glass bulb face each other to form one corner part. Yes. Further, the bent portion is bent so that the straight pipe portion is positioned substantially on the same plane. The glass bulb is sealed with a configuration in which the free end portion where the bent portion of the straight tube portion located on both sides is not connected seals the stem or forms a pinch seal portion at the end portion. And it arrange | positions so that this both ends may adjoin, and it is comprised by the polygon as a whole. When the fluorescent lamp is of an electrode type, the electrode mount that supports the electrode on the stem or pinch seal portion can be airtightly supported.

  In addition, the following two modes are allowed as the configuration for communicating so as to form a single discharge path while the glass bulbs having a polygonal shape are multiple. That is, the first aspect is an aspect in which the outer annular portion and the inner annular portion are arranged concentrically within substantially the same plane. A 2nd aspect is an aspect with which the some annular part of substantially the same size overlaps up and down. In any of the above embodiments, a protective film and a phosphor layer, which will be described later, are formed in the state of a glass tube on a straight tube, and then a pair of electrodes are sealed at both ends of the glass tube to form a straight tubular glass After forming the valve, it is processed and molded into an annular shape in a state where it is softened by heating. And a some discharge part is formed by connecting a some annular part using a connecting pipe.

  The glass bulb is made of soft glass such as soda lime glass, barium silicate glass and lead glass, but may be made of hard glass such as borosilicate glass or quartz glass if necessary. The wall thickness of the straight tube portion of the glass bulb is preferably about 0.8 to 1.2 mm, but is not limited thereto. In addition, in order to exhaust the inside of a glass bulb | bulb and to enclose a discharge medium, one or a pair of thin tubes can be attached.

  <Protective film> The protective film has a fine particle layer and large-diameter particles. The fine particle layer is made of fine particles having an average particle diameter of 100 nm or less, preferably 10 nm or more, and is attached to the inner surface of the glass bulb. The fine particles are metal oxides having an average primary particle size of 100 nm or less, preferably an average particle size of about 10 to 50 nm, such as silica, γ, which has been used as a general protective film constituent material. Such as alumina. When the average particle size of the fine particles is 100 nm or less, the protective film can be exerted to suppress the implantation of mercury into the glass bulb. If the average particle size of the fine particles is less than 10 nm, it is difficult to produce, so it becomes difficult to obtain or costs increase, and the particles are aggregated when dispersed in a suspension for coating a protective film. It becomes easy and it becomes difficult to make a dense film.

  The fine particles used to form the fine particle layer preferably have a spherical shape or a shape close thereto. In particular, when the area of the orthographic image of the fine particles is S1 and the area of the circumscribed circle of the orthographic image is S2, it is preferable that the expression 0.7 ≦ S1 / S2 ≦ 1.0 is satisfied.

The means for forming the fine particles is not particularly limited. For example, when silica is used as the fine particles, it is preferable to use fine particles formed from silicon or a silicon compound that is gaseous or liquefied in an atmosphere containing oxygen by a PVS (Physical Vapor Synthesis) method or the like. Since SiO ₂ formed by such a method has little residual of impure gas and high binding properties, by using this as a protective film material, a fluorescent lamp having excellent protective film strength and high luminous flux maintenance factor can be obtained. Can be provided.

A part of the large-diameter particle is buried in the fine particle layer, and the remaining part protrudes from the fine particle layer to the discharge space side by forming an appropriate gap between the particles and acts as a component of the protective film. In this way, since a porous coating is formed between the large particles on the discharge space side without many fine particles, the phosphor particles enter the gaps between the large particles, so that the phosphor Prevents peeling of the layer. In addition, a part of the large particles may be separated from the fine particle layer alone or together with the fine particles and enter mainly into the base layer of the phosphor layer, so that the large particles reinforce the binding with the phosphor particles. Act on. The large-sized particles, the average particle size of the primary particle size Ru using the above particles 1 [mu] m. Preferably the average particle size is about 1-10 μm, more preferably the average particle size is about 2-7 μm. Therefore, the large-diameter particles are allowed to be in the particle size range of general phosphor particles, and furthermore, the phosphor particles are allowed to be used as large-diameter particles.

  The large particles can be selected from alkaline earth metal salts, α-alumina, phosphors and the like, and can be used alone or in combination. The alkaline earth metal salt can be selected from alkaline earth metal phosphates and alkaline earth metal aluminates and used alone or in combination.

  When a phosphor is used as the large-diameter particles, it may be the same as or different from the phosphor that forms the phosphor layer described later. However, since the large-diameter particles that act as a protective film are partially embedded in the fine particle layer as described above, and the remaining portion protrudes from the fine particle layer to the discharge space side, even if fluorescent particles are provided. Even if it is the same type of phosphor as the body layer, it can be distinguished.

  The means for forming the protective film on the inner surface of the glass bulb is not particularly limited. For example, by adjusting a suspension containing fine particles and large-diameter particles at a predetermined ratio and flowing down into the glass tube, the fine particles and large-particles adhering to the glass tube are dried, so that the inner surface of the glass tube is dried. While the fine particle layer is formed, the protective film of the present invention can be obtained in a state in which a part of the large particle is buried in the fine particle layer and the remaining part protrudes from the fine particle layer by forming an appropriate gap. As will be described later, after forming the protective film on the inner surface of the glass tube, after forming the phosphor layer, the electrodes are attached to form the glass bulb, and then the glass bulb is bent and bent The part can be formed.

  Therefore, the preferable combination of the average particle diameter of the fine particles and large particles in the protective film is such that the average particle diameter of the fine particles is 50 nm or less and the average particle diameter of the large particles is in the range of 1 to 10 μm. More preferably, the average particle size of the fine particles is in the range of 10 to 40 nm, and the average particle size of the large particles is in the range of 2 to 7 μm.

Next, when preparing the suspension, the large-diameter particles are preferably 50 to 90%, more preferably 85% or less or / and 55% or more, based on the total mass of the large-diameter particles and fine particles. Accordingly, the fine particles can be 50 to 10%, more preferably 15% or more and / or 45% or less in the same ratio as described above. If the above range is arranged with the mass of the fine particles being Wg and the mass of the large-diameter particles being Wp, the mass ratio is in the range of Wg: Wp = 15 to 45:85 to 55.
As the content ratio of large-diameter particles becomes smaller than the above range, the luminous flux of the fluorescent lamp tends to decrease. Further, even if the content ratio of the large-diameter particles is larger than the above range, the luminous flux of the fluorescent lamp tends to be lowered depending on the coating amount.

  Further, the preferable range of the thickness of the protective film is that when the film thickness of the fine particle layer portion located on the inner surface of the glass bulb is t (μm) and the average particle diameter of large particles is p (μm), the formula 0 < This is a range satisfying t / p <1. Within this range, a structure in which a part of the large-diameter particles are buried in the fine particle layer and the remaining part protrudes from the fine particle layer can be reliably and easily formed, which is a preferable embodiment. Within the range of the above mathematical formula, the surface of the protective film becomes smooth as the ratio t / p approaches 1. Further, as the ratio t / p approaches 0, more gaps are formed on the surface of the protective film, and the unevenness becomes prominent. When the ratio t / p is 1, the effect of the present invention cannot be obtained. Furthermore, when the absolute value of the protective film thickness is increased, cracking, peeling and impure gas emission tend to increase.

  <Regarding the phosphor layer> The phosphor layer is formed on the inner surface side of the protective film formed on the inner surface of the glass bulb, that is, on the discharge space side. Therefore, as is clear from the above description, the phosphor layer is applied and formed on the inner surface of the straight tubular bulb before forming the bent portion. The phosphor layer is allowed to contain about 1 to 3% of fine particles as a binder between the phosphor particles and to the protective film. The fine particles in this case are preferably made of a metal oxide. As the metal oxide, for example, one or more kinds selected from the group consisting of γ-alumina, yttria, silica, zinc oxide, titania and ceria can be selected and used. However, the fine particles of the protective film and the fine particles in the phosphor layer may be the same or different.

The phosphor layer is formed to have an appropriate thickness, but preferably has an average deposition amount of about 3 to 7 mg / cm ² in the main part of the inner surface of the glass bulb. Further, in the bent portion, the phosphor layer is preferably formed so that the deviation of the deposition amount is ± 15% with respect to the average value. Further, the phosphor layer can be formed on the protective film by flowing the coating liquid from one end side of the glass base tube on which the protective film is formed on the inner surface. In this case, if a phosphor layer is formed by injecting the phosphor coating solution from the end opposite to the end of the blank tube into which the coating solution for the protective film has been introduced, the total of the protective film and the phosphor layer is obtained. It becomes easy to make the film thickness uniform over the entire length of the raw tube. It is also acceptable to form the phosphor layer in multiple layers such as two layers. In this case, the inflow ends of the coating liquid are both ends of the raw tube, and the inflow ends are alternately switched, so that the thickness of the phosphor layer is made uniform in the longitudinal direction of the raw tube.

  In addition, when the phosphor is used as at least a part of the large-sized particles in the protective film, the boundary between the protective film and the phosphor layer in the present invention becomes unclear, but as described above, the protective film is The fine particle layer is formed by adhering to the inner surface of the glass bulb, a part of the large-diameter particle is embedded in the fine particle layer, and the remaining part protrudes from the fine particle layer so that it can be identified. .

  <About discharge generating means> The discharge generating means is means for causing discharge inside the glass bulb, that is, discharge of the discharge medium. In the present invention, any known electrode-type and electrodeless-type discharge generation means can be selectively employed as appropriate. In the case of the electrode type, either an internal electrode type in which the electrode is disposed inside the glass bulb or an external electrode type in which the electrode is disposed on the outer surface of the glass bulb may be used. Further, the external electrode type includes an aspect in which a pair of electrodes are both disposed facing the outer surface of the glass bulb, and an aspect in which one electrode is an external electrode and the other electrode is an internal electrode. However, the present invention may be any of them. However, the electrode-type discharge generating means is suitable as a fluorescent lamp for general illumination.

  <Regarding the discharge medium> The discharge medium is sealed inside the glass bulb, and is discharged by the action of the discharge generating means to generate radiation. As a specific configuration of the discharge medium, various known discharge media can be appropriately and selectively employed to generate desired radiation. In general, however, a combination of a starting gas, such as a noble gas, and a luminescent medium, such as mercury, to obtain primarily the desired radiation is used.

  <Regarding the Action of the Present Invention> For example, in the case of a glass bulb having an outer diameter of 16 mm, when the radius of curvature inside the bent portion is 30 mm, the extension rate outside the bent portion is 1.6 times or more. Since the protective film is formed as described above, the large-diameter particles in the protective film are easily connected to the phosphor particles of the phosphor layer, and the phosphor layer is cracked or bent at the curved portion having a small curvature radius as a whole. Peeling is less likely to occur. As a result, cracking and peeling at the curved portion having a small radius of curvature are prevented.

  When phosphor particles are used for the large-diameter particles in the protective film, it is not necessary to apply a large number of phosphors in order to achieve a desired luminous efficiency, which is economical.

According to the present invention, there is provided a protective layer having a fine particle layer of fine particles having an average particle diameter of 100 nm or less and a large particle having an average particle diameter of 1 μm or more, part of which is buried in the fine particle layer and the remaining part protruding from the fine particle layer. As a result, the phosphor layer is less likely to be cracked or peeled even in a curved portion having a small radius of curvature, and therefore a fluorescent lamp having a good appearance and a lighting device including the same can be provided.

  In addition, since the thickness of the fine particle layer in the protective film is smaller than the average particle size of the large particles, it is easy to form a state in which a part of the large particles are buried in the fine particle layer and the remaining part protrudes from the fine particle layer. A lamp and an illumination device including the lamp can be provided.

  DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments for implementing a fluorescent lamp and an illumination device of the present invention will be described with reference to the drawings.

  1 to 3 show a first embodiment for carrying out the fluorescent lamp of the present invention, FIG. 1 is an enlarged front view showing a part of the cross section, and FIG. 2 shows a protective film and a phosphor layer. The principal part expanded sectional view typically shown, FIG. 3: is a principal part expanded disassembled sectional view which shows typically the manufacturing process of a protective film. In the figure, the fluorescent lamp FL includes a glass bulb 1, a protective layer 2, a phosphor layer 3, discharge generation means 4 and 4, a discharge medium and a base B.

  The glass bulb 1 has a curved portion with a small curvature, that is, a bent portion, by locally heating and softening one glass base tube, and has a substantially square shape as a whole. And it is formed with three comparatively long straight pipe parts 1a which make three sides of a square, a pair of comparatively short straight pipe parts 1b, and four bent parts 1c which form a corner part, respectively. Further, the pair of relatively short straight pipe portions 1b have end portions 1d that are in a straight line shape, are opposed to each other with their tips approaching each other, and a thin tube is formed although not shown.

  The three straight pipe portions 1a and the pair of straight pipe portions 1b and 1b constitute four square sides adjacent to each other, and a base B which will be described later so as to bridge between the tip portions of the pair of straight pipe portions 1b and 1b. Is attached to form a closed square. The bent portion 1c connects a pair of adjacent straight pipe portions 1a at right angles. Each end 1d of the pair of straight tube portions 1b and 1b is formed by sealing a flare stem of an electrode mount (not shown) to the end of the glass tube before bending the glass tube to be described later. Is sealed.

  The electrode mount is an assembly composed of a flare stem, a thin tube, a discharge generating means 4 and a lead wire. The electrode mount is assembled in advance and the flare portion of the flare stem is glass-welded to the end of the glass base tube. Depending on the embodiment, the pair is sealed. Then, the glass bulb 1 is sealed, a thin tube described later is connected to the glass bulb 1, the discharge generating means 4 described later is sealed, and the lead wire is derived therefrom. Further, at both end portions 1d of the glass bulb 1, a not-shown throttle portion is formed by molding when the flare stem is sealed. However, if desired, other known sealing structures, such as a pinch seal structure that directly seals an electrode mount that does not include a stem glass, or a structure that seals an electrode mount that includes a button stem or a bead stem via the stem glass. It can seal using.

  Then, when the glass bulb 1 is a straight tubular glass tube, a protective film 2 and a phosphor layer 3 which will be described later are formed on the inner surface of the glass bulb 1 and a pair of electrodes 4 and 4 are sealed. When heated and softened, the four bent portions 1c, the three straight tube portions 1a, and the pair of straight tube portions 1b are formed to form a substantially square shape. And it is arranged contiguously on the same plane. At this time, the length L of one side of the glass bulb 2 is preferably 200 mm or more. In this embodiment, L is about 300 mm. The straight pipe portion 1b has a pipe outer diameter of 12 to 20 mm and a wall thickness of 0.8 to 1.5 mm. In this embodiment, the pipe inner diameter is about 16 mm and the wall thickness is about 1.2 mm.

  As shown in FIG. 2, the protective film 2 includes a fine particle layer 2a and large-diameter particles 2b. The fine particle layer 2a is made of silica having an average particle diameter of several tens of nanometers, and is formed as a dense coating on the inner surface of the glass bulb 1, and has a film thickness of, for example, 2 to 3 μm. The large-diameter particles 2b are made of phosphor particles having an average particle diameter of 5 μm, a part of which is embedded in the fine particle layer 2a and the remaining part protrudes from the fine particle layer 2a. Since almost no silica fine particles are present between the large particles 2b on the discharge space side (phosphor layer 3 side), a gap having the same size as the average particle diameter is formed between the large particles 2b. Yes. The phosphor layer 3 is formed so that the phosphor particles enter the gap.

  Further, as shown in FIG. 3, the protective film 2 is formed by flowing a suspension prepared in advance into a glass tube and drying it in a previous step of forming the phosphor layer 3. The suspension is configured such that a phosphor of the same type as the phosphor layer 3 described later and fine particles are mixed in a ratio of 10 to 60% of the weight and suspended in a solvent such as water. Can do. In addition, the favorable protective film 2 was able to be obtained using the suspension which mixed silica fine particle 30% by mass ratio with respect to the fluorescent substance particle as an Example. The fine particle layer 2a is formed by depositing the suspension in the glass tube by surface tension when applied to the inner surface of the glass tube. Further, when the phosphor layer 3 is applied and formed on the protective film 2, the above-mentioned gap is formed between the large-diameter particles 2b by causing the silica fine particles between the large-diameter particles 2b to flow out to the inner surface side of the glass tube. become.

The phosphor layer 3 is disposed on the protective film 3, that is, on the discharge space side, and adjusts a suspension obtained by adding fine particles similar to the protective film of 2% by mass to the three-wavelength phosphor type phosphor particles. After being coated and dried, it is formed by baking together with the protective film 2 and has a thickness of about 10 to 30 μm. Three-wavelength phosphors include BaMg ₂ Al ₁₆ O ₂₇ : Eu ²⁺ as a blue phosphor having an emission peak wavelength near 450 nm, and a green phosphor having an emission peak wavelength near 540 nm (La, Ce, Tb) PO ₄ , Y ₂ O ₃ : Eu ³⁺ or the like is applicable as a red phosphor having an emission peak wavelength in the vicinity of 610 nm, but the present invention is not limited to these.

  Thus, when excited mainly by ultraviolet light having a wavelength of 254 nm, which is emitted by mercury vapor discharge of a discharge medium described later, the phosphor layer 3 generates white light having a correlated color temperature of 5000K, for example. However, the fluorescent lamp 3 can be configured using other known phosphors such as a halophosphate phosphor, if desired.

  In the present embodiment, the discharge generating means 4 and 4 are formed of a pair of internal electrode type electrodes. The electrodes constituting the discharge generating means 4 are in the form of a filament made of a tungsten triple coil coated with an electron-emitting substance, and are sealed at both ends 1d and 1d of the glass bulb 1, respectively. The discharge generating means 4 and 4 are supported by being connected between the inner ends of a pair of lead wires sealed to the flare stem.

  The discharge medium is composed of a rare gas and mercury vapor, and argon (Ar) is enclosed as a rare gas at a low pressure, for example, a pressure of about 320 Pa. As the rare gas, one or more kinds such as neon (Ne) and krypton (Kr) can be selected and sealed instead of or in addition to argon (Ar). Mercury vapor is configured to be supplied from the main amalgam 6. The main amalgam 6 is a mercury vapor pressure control amalgam made of a bismuth (Bi) -tin (Sn) -lead (Pb) system, and is placed in the narrow tube 1e. If desired, an auxiliary amalgam can be used in addition to the main amalgam. The auxiliary amalgam is composed of an indium (In) film plated on a stainless steel substrate, reacts with mercury vapor in the glass bulb 1 to form amalgam, and mainly supplies mercury vapor at start-up to raise the luminous flux. Acts to speed up. In this embodiment, the main amalgam 6 for controlling the mercury vapor pressure is used to maintain the mercury vapor as the discharge medium at a predetermined pressure. However, the cross-sectional shape of the bent portion 2c of the glass bulb 1 is substantially the same. Liquid mercury can also be used if the coldest part is formed in the part by forming it into a triangular shape or a substantially rectangular shape. That is, when the bent portion 2c has a shape protruding outward, the discharge path is formed on the inner side, so that the non-discharge region can be enlarged to obtain an optimum coldest portion having a high cooling effect, and mercury vapor Temperature characteristics can be improved without using an amalgam for pressure control.

  The base B includes four base pins 7, and bridges between both ends 1 d of the pair of straight pipe portions 1 b and 1 b of the glass bulb 1 to form one side of a quadrangle. The cap pin 7 is connected to a lead wire (not shown) led out from the electrode 4 to the outside.

  In this embodiment, the fluorescent lamp FL can have the following dimensions. That is, the equivalent of the conventional 30W-type annular fluorescent lamp is formed such that the total length L 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. . This fluorescent lamp has a rated lamp power of 20 W and a lamp power of 27 W at high output characteristics. Also, the equivalent of the conventional 32W ring fluorescent lamp is formed such that the total length L of the glass bulb 2 is 299 mm, the maximum inner width is 267 mm, the outer diameter of the tube is 16 mm, and the thickness of the glass bulb 2 is 1.0 mm. . This 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 L 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. This fluorescent lamp has a rated lamp power of 34 W and a lamp power of 48 W at the time of high output characteristics.

Next, the operation in this embodiment will be described. When a high frequency voltage is applied between the discharge generating means 4 and 4 via the base B, the fluorescent lamp FL is lit by low-pressure mercury vapor discharge generated in the discharge vessel DV. The fluorescent lamp FL is lit so that the lamp 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 50 lm / W or more. The lamp current density, which is the lamp current per cross-sectional area of the straight pipe portion 1b, is 75 mA / cm ² or more. In this embodiment, the lamp power is 50 W, the lamp current is 380 mA, and the lamp efficiency is 90 lm / W.

4 and 5 are electron micrographs showing cross sections of the protective film and the phosphor layer in each part of the embodiment of the present invention. FIG. 4 shows a straight pipe part and FIG. 5 shows a bent part. In these photographs, the magnification is 2000 times, the length of the straight line at the bottom is 10 μm, and the glass bulb, the protective film, and the phosphor layer are stacked in this order from the bottom to the top of the photograph. In this example, the protective film is made of γ-alumina (γ-Al ₂ O ₃ ) and fine particles of strontium phosphate (Sr ₂ P ₂ O ₇ ). In the protective film, a portion in contact with the glass bulb forms a fine particle layer, large-diameter particles are dispersed in the fine particle layer, and the upper portion of the large-diameter particles protrudes upward from the fine particle layer. Furthermore, large-sized particles and a part of the fine particles in the protective film are embedded in the phosphor layer while continuing to the fine particle layer, or are released from the fine particle layer and embedded in the phosphor layer. Yes.

  Next, with reference to Table 1, the relationship between the combination of the fine particles constituting the protective film and the large-diameter particles in the above example, the peeling, and the luminous flux maintenance factor will be described. Table 1 summarizes the results of lighting tests on 20 fluorescent lamps having different combinations of fine particles and large particles. The phosphor particles have an average particle size of 3 μm, and the mixing mass ratio of the fine particles and large particles is 1: 4. In the table, the numerical values of “fine particles” and “large particles” are average particle diameters, and “peeling” is the presence or absence of peeling mainly occurring at the interface between the protective film and the phosphor layer in the bent portion 1c of the glass bulb 1. “Luminous flux maintenance factor” indicates a value (%) at 12,000 hours of lighting. In addition, the symbol in the table indicates that ○ is not peeled off, Δ is minute peeling, and × is that the lighting test is not performed because peeling is remarkable.

表１から理解できるように、保護膜は、微粒子が本発明の範囲であればよいことが分かる。なお、微粒子が５００ｎｍおよび１０００ｎｍの場合には、分子間力による結着力が低下して主に屈曲部１ｃにおいて剥がれが生じるものと考えられる。また、表１に示す保護膜の構成の場合、径大粒子が０．５μｍでは剥がれが顕著になり、１０μｍでは径大粒子が脱落しやすくなった。

As can be understood from Table 1, it is understood that the protective film may be fine particles within the scope of the present invention. In addition, when the fine particles are 500 nm and 1000 nm, it is considered that the binding force due to the intermolecular force is reduced and peeling occurs mainly at the bent portion 1c. Further, in the case of the protective film configuration shown in Table 1, peeling was significant when the large particles were 0.5 μm, and the large particles were likely to fall off at 10 μm.

  Further, with reference to Table 2, the relationship between the combination of the fine particles in the protective film and the large-diameter particles and the amount of phosphor adhering to the combination and peeling in the embodiment will be described. In Table 2, the numerical values in the columns of γ-alumina and strontium phosphate indicate the mixing ratio, and the symbols in the peeling column have the same evaluation as in Table 1. The blank part in the table is the same as the numerical value entered in the field above the blank, but the entry is omitted. Note that γ-alumina was formed using a water-soluble slurry.

図６は、本発明の実施例において保護膜の径大粒子／微粒子の配合比と全光束の関係について蛍光体付着量をパラメータとして示すグラフである。図において、横軸は径大粒子／微粒子の配合比（質量％）を、縦軸は相対光束を、それぞれ示す。なお、このときの保護膜２の付着量は０．４６ｍｇ／ｃｍ^２である。

FIG. 6 is a graph showing the amount of phosphor adhering as a parameter for the relationship between the large particle / fine particle blend ratio of the protective film and the total luminous flux in the example of the present invention. In the figure, the horizontal axis represents the ratio of large particles / fine particles (mass%), and the vertical axis represents the relative luminous flux. In addition, the adhesion amount of the protective film 2 at this time is 0.46 mg / cm ² .

  As can be seen from the figure, the range of 67 to 88% by mass of the large particle / fine particle blend ratio was particularly suitable.

    FIG. 7 is a front view showing a second embodiment for implementing the fluorescent lamp of the present invention. In this embodiment, the glass bulb 1 has a concentric double ring structure.

  That is, the glass bulb 1 includes an outer annular portion 1A, an inner annular portion 1B, and a communication portion 1C arranged in the same plane, and is formed by forming one bent discharge path. The outer annular portion 1A and the inner annular portion 1B are similar to each other in a substantially square shape except that the outer diameters of the tubes are the same. The communication portion 1 </ b> C communicates the outer annular portion 1 </ b> A and the inner annular portion 1 </ b> B, and forms one discharge path inside the glass bulb 1. The discharge path passes through the straight tube portions 1a2 and 1a3 counterclockwise from the portion of one end 1d of the straight tube portion 1a1 in the outer annular portion 1A inserted into the base B, and passes through the straight tube portions 1a4 and 1a3. To the other end portion 1d of the inner annular portion 1B through the communication portion 1C and pass through the straight pipe portions 1a4 ', 1a3' and 1a2 'in a clockwise direction. It reaches the portion inserted into the base B at one end 1d ′ of the tube portion 1a1 ′.

  1 C of communicating parts connect the pipes which protruded from each cyclic | annular part 1A, 1B by blowing from the edge part 1d side of the left side in the figure of the outer side annular part 1A and the inner side annular part 1B, and connect them. Is formed by. The communication portion 1C is disposed at a position 10 to 40 mm away from the tip so that a space where the discharge arc does not enter is formed inside the end portion 1d of the outer annular portion 1A and the inner annular portion 1B. Is set. In order to make it easy to manufacture the communication portion 1C by the above method, it is preferable to set the gap g formed between the outer annular portion 1A and the inner annular portion 1B to 5.0 to 10.0 mm. Further, the communication portion 1C is arranged at a position slightly separated from the base B in the drawing, but if necessary, it can be configured so as to be disposed inside the base B and not visible from the outside. Further, the communication part 1 </ b> C may be configured such that the position adjacent to the base B or a part thereof is located in the base B.

  The size of one side of the square of the outer annular portion 1A in the glass bulb 1 is preferably 250 mm or more, and the size of one side of the square of the inner annular portion 1B is preferably 200 mm or more. Moreover, the pipe outer diameter of both annular parts 1A and 1B is 12 to 20 mm, and the wall thickness is 0.8 to 1.5 mm. As an example, the size of one side of the square of the outer annular portion 1A is 300 mm, the size similar to the inner annular portion 1B is 250 mm, the outer diameter of the tube is 14 mm, and the wall thickness is 1.2 mm. Further, the bent portions 1c and 1c ′ of the outer annular portion 1A and the inner annular portion 1B are preferably in the following range. That is, the outer curvature radius of the outer annular portion 1A is 45 to 70 mm (Example 56.5 mm), the inner curvature radius is 30 to 55 mm (Example 40 mm), and the outer curvature radius of the inner annular portion 1B is 25 to 45 mm (Example). 31.5 mm), and the inner radius of curvature is preferably set to 13 to 20 mm (Example 15 mm). It is desirable that the outer diameters of the pipes at the bent portions 1c and 1c ′ are molded so as to be substantially equal to the outer diameters of the pipes 1a1 to 1a4 and 1a1 ′ to 1a4 ′.

  In the base B, sealing is performed on one end 1d inserted into the base B from the upper side and one end 1d 'of the inner annular portion 1B from the upper side in the figure of the outer annular portion 1A that becomes both ends of the discharge path. A lead wire led out from the pair of electrodes (not shown) is connected to the base pin.

  If desired, the gap g between the outer annular portion 1A and the inner annular portion 1B is filled with a buffering substance such as silicone resin to fix the annular portions 1A, 1B, thereby reducing the vibration resistance strength of the glass bulb 1. Can be increased.

Next, the lighting operation of the fluorescent lamp in this embodiment will be described. Lamp input power 40W or more (Example 60 W), the lamp current 200mA above (Example 380 mA), tube wall loading 0.05 W / cm ² or more, is turned so that the lamp efficiency 50 lm / W or more (Example 90 lm / W) The Further, the lamp current density per cross-sectional area in the straight pipe portions 1a1 to 1a4 and 1a1 ′ to 1a4 ′ is 75 mA / cm ² or more. In addition, the temperature of the glass bulb 1 during lighting rises to 80 ° C., but since the coldest part of the optimum temperature is formed, the mercury vapor pressure in the glass bulb 1 becomes appropriate and high lamp efficiency can be obtained. it can.

    FIG. 8 is a side view showing a ceiling-mounted lighting fixture as one mode for carrying out the lighting device of the present invention. In the figure, the same parts as those in FIG. The ceiling-mounted lighting fixture includes a lighting fixture body 11, a fluorescent lamp FL, and a high-frequency lighting circuit.

  The luminaire main body 11 is used by being attached to a ceiling, and includes a white reflector 11a, a lamp socket (not shown), a lamp holder 11b, and the like. The white reflector 11a is disposed at the center of the lower surface of the luminaire main body 11, and has a quadrangular pyramid shape, that is, a pyramid shape. The lamp socket is a connection means for supplying power to the fluorescent lamp FL, and is disposed at a position facing the base B of the fluorescent lamp FL, and is attached to the base pin p. The lamp holder 11b holds the fluorescent lamp FL by horizontally holding the glass bulb 1 of the fluorescent lamp.

  The fluorescent lamp FL is the fluorescent lamp shown in FIG. 7, and the base B is connected to the lamp socket, and the glass bulb 1 is held by the lamp holder 11b, so that the fluorescent lamp FL is mounted at a predetermined position on the luminaire main body 11. .

  The high-frequency lighting circuit (not shown) is means for obtaining an input from a low-frequency AC power source, converting it to high-frequency power, and supplying a high-frequency output to the fluorescent lamp FL via the lamp socket 11b. However, it is arrange | positioned in the space formed in the back of the white reflector 11a in the lighting fixture main body 11. FIG.

  Thus, since the quadrangular pyramid-shaped white reflector 11a of the luminaire main body 11 is disposed at the center of the fluorescent lamp FL having a quadrangular shape, the light distribution characteristic in the downward direction of the luminaire is quadrangular, and the rectangular room It is suitable for uniform illumination.

The front view which expands the one part cross section and shows the 1st form for implementing the fluorescent lamp of this invention Similarly, the principal part expanded sectional view which shows a protective film and a fluorescent substance layer typically Similarly, an enlarged exploded sectional view schematically showing the manufacturing process of the protective film The electron micrograph which shows the cross section of the protective film and fluorescent substance layer of the straight pipe | tube part in one Example of this invention Similarly, an electron micrograph showing a cross section of the protective film and phosphor layer of the bent portion The graph which shows the amount of fluorescent substance adhesion as a parameter about the relationship between the compounding ratio of the large particle / fine particle of a protective film, and a total luminous flux in the Example of this invention The front view which shows the 2nd form for implementing the fluorescent lamp of this invention The side view which shows the ceiling mounting type lighting fixture as one form for implementing the illuminating device of this invention

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Glass bulb, 2 ... Protective film, 2a ... Fine particle layer, 2b ... Large diameter particle, 3 ... Phosphor layer

Claims (4)

A glass bulb having a curved portion;
A fine particle layer made of fine particles with an average particle size of 100 nm or less and attached to the inner surface of a glass bulb, and a large particle with an average particle size of 1 μm or more, part of which is buried in the fine particle layer and the remaining part protruding from the fine particle layer A protective film comprising:
A phosphor layer formed on the protective film of the glass bulb;
A discharge medium enclosed in a glass bulb;
Discharge generating means for generating discharge inside the glass bulb;
A fluorescent lamp characterized by comprising:   2. The fluorescent lamp according to claim 1, wherein the protective film has a fine particle layer whose thickness is smaller than the average particle diameter of the large particles. The fluorescent lamp according to claim 1 or 2 , wherein the protective film has an average particle size of fine particles of 50 nm or less and an average particle size of large particles of 1 to 10 µm. A lighting device body;
The fluorescent lamp according to any one of claims 1 to 3, which is disposed in the lighting device body;
An illumination device comprising:

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