JP2009205880A - Electrodeless discharge lamp and lighting apparatus - Google Patents

Abstract

[PROBLEMS] To provide a loop-shaped bulb, which has good startability after being stored in a dark place in a light-off state, and prevents a decrease in luminous flux of a light-emitting portion on the appearance of the bulb and uneven emission color. An electrodeless discharge lamp and a lighting fixture using the same are provided.
An electrodeless discharge lamp includes a loop-shaped bulb 1 formed of a light-transmitting material and containing an amalgam (not shown) made of zinc and mercury and a discharge gas. The ferrite cores 2 and 2 that are arranged so as to cover the part and are formed of a magnetic material, and induction that generates a high-frequency electromagnetic field in the valve 1 by being wound around at least a part of the ferrite core 2 and energized with a high-frequency current. A coil 3. The long afterglow phosphor layer 13b is formed on the inner wall of the portion of the bulb 1 covered with the ferrite cores 2 and 2.
[Selection] Figure 1

Description

  The present invention relates to an electrodeless discharge lamp used for lighting applications, ultraviolet sterilization applications, and the like, and a lighting fixture using the same.

  Conventionally, an electrodeless discharge lamp provided with a bulb formed in a loop shape and filled with a discharge gas has been proposed (see Patent Documents 1 and 2), and this type of electrodeless discharge lamp was used. Lighting fixtures are generally known. Here, an electrodeless discharge lamp is one in which mercury vapor and a rare gas such as argon or krypton are enclosed in a bulb, and the mercury vapor is excited by a high-frequency electromagnetic field generated in the bulb to emit light. In the electrodeless discharge lamp apparatus having the electrodeless discharge lamp described above, two ring-shaped ferrite cores surrounding the side wall of the bulb are mounted at two locations of the bulb, and an induction coil is wound around each ferrite core. Yes. Each induction coil is supplied with a high frequency current from a lighting circuit having a high frequency power source.

  In the electrodeless discharge lamp device described above, when a high frequency current of about several hundred kHz is applied to each induction coil, an electric field is generated in the bulb of the electrodeless discharge lamp by electromagnetic induction, and the electric field is enclosed in the bulb. It acts on the discharge gas and excites mercury vapor contained in the discharge gas to generate ultraviolet rays. Here, when the fluorescent material is applied to the inner wall of the bulb, the generated ultraviolet light is irradiated onto the fluorescent material applied to the inner wall of the bulb and converted into visible light, so that it can be used as an electrodeless fluorescent lamp. it can. On the other hand, when the bulb is formed of glass having a high ultraviolet transmittance and the phosphor is not coated on the inner wall thereof, it can be used as an electrodeless ultraviolet lamp. In these electrodeless discharge lamps, there is no electrode that causes a short life in the bulb, so that the life can be extended.

  In general, an electrodeless discharge lamp may be delayed in starting or may not start after being stored in a dark place for a long time in an unlit state. This is caused by a shortage of initial electrons in the bulb of the electrodeless discharge lamp. In the case of a general electrode fluorescent lamp, as a method for improving startability after being stored in a dark place for a long time with the light turned off (hereinafter referred to as dark startability), a method of preheating the electrode and generating initial electrons However, in the case of an electrodeless discharge lamp, since the electrode does not exist in the bulb, the above method cannot be adopted. Therefore, in the electrodeless discharge lamp, it is necessary to improve the dark startability by a method different from that of the electroded fluorescent lamp.

Here, a long afterglow phosphor (for example, europium, dysprosium co-activated strontium aluminate phosphor (SrAl ₂ O ₃ : Eu, Dy or Sr ₄ Al ₁₄ O) is formed on the entire inner wall of the U-shaped bulb. ₂₅ : Eu, Dy) has been proposed to improve the dark startability (Patent Document 3) The long afterglow phosphor is a commonly used phosphor such as red. Afterglow compared with phosphors such as phosphor (Y ₂ O ₃ : Eu ³⁺ ), green phosphor (LaPO ₄ : Ce ³⁺ , Tb ³⁺ ), blue phosphor (BaMg ₂ Al ₁₆ O ₂₇ : Eu ²⁺ ) In a phosphor that is used for a long time and is usually used, it takes several tens of msec until the emission intensity becomes 1/10 of that when the lamp is turned on. Tens of hours It is a top.

  However, the long afterglow phosphors described above generally have lower luminous efficiency than commonly used phosphors, and the luminous flux decreases when used over the entire inner wall of the electrodeless discharge lamp. Further, since the emission color of the long afterglow phosphor is different from the emission color of the normally used phosphor, for example, when used in the form of being applied to a part of the inner wall of the light emitting portion on the exterior of the bulb, In the light emitting portion on the appearance, the emission color is different between the portion where the long afterglow phosphor is applied and the portion where the phosphor is applied, and unevenness may occur.

An electrodeless discharge lamp 100 ′ as shown in FIG. 6 has been proposed as an electrodeless discharge lamp that prevents unevenness in emission color in the light emitting portion on the appearance of the bulb as described above (see Patent Document 4). ). Here, in the electrodeless discharge lamp 100 ′ configured as shown in FIG. 6, an opening (not shown) is formed in the lower part of the spherical bulb 1 ′, and the opening of the bulb 1 ′ is opened from the opening to the inside of the bulb 1 ′. A cylindrical tube 2 'continuous at the portion protrudes. A reflective film 9 ′ made of alumina (Al ₂ O ₃ ) is formed on the outer peripheral wall of the cylindrical tube 2 ′, and the long afterglow phosphor is formed on the reflective film 9 ′. A long afterglow phosphor layer 10 ′ is formed, and a phosphor layer 5 made of the above-described commonly used phosphor is formed on the inner wall of the bulb 1 ′ other than the cylindrical tube 2 ′. 'Is formed. Thus, in the electrodeless discharge lamp 100 ′, the long afterglow phosphor layer 10 ′ is formed only on the outer peripheral wall of the cylindrical tube 2 ′ inside the bulb 1 ′, and the portion other than the cylindrical tube 2 ′, That is, in the portion of the bulb 1 ′ that is the light emitting portion on the appearance, a portion coated with the long afterglow phosphor is not formed, so that the light emitting portion on the appearance of the bulb 1 ′ is improved while improving the dark startability. This prevents the occurrence of uneven emission color.

Further, as a method for improving the dark startability, in addition to the method using a long afterglow phosphor as described above, a method in which a dark place starter applied on a metal mesh or the like is disposed in the bulb. (See Patent Document 5).
JP 10-511806 gazette JP 11-191398 A JP-A-11-111028 JP 2004-234945 A JP 2004-079444 A

  However, in an electrodeless discharge lamp having a loop-shaped bulb, a cylindrical tube 2 ′ that protrudes into the bulb 1 ′ of the electrodeless discharge lamp 100 ′ shown in FIG. Is difficult.

  Further, in an electrodeless discharge lamp having a loop-shaped bulb, it is structurally difficult to dispose a metal mesh in the bulb as in the electrodeless discharge lamp described in Patent Document 5. Moreover, when forming the structure which hold | maintains the said metal mesh inside, it is necessary to add a complicated process to the production process of a valve | bulb, and it is very disadvantageous from a viewpoint of the manufacturing cost of an electrodeless discharge lamp.

  The present invention has been made in view of the above-mentioned reasons, and its purpose is to provide a loop-shaped valve, which has a good startability after being stored in a dark place for a long time in an extinguished state, and on the appearance of the valve. It is an object of the present invention to provide an electrodeless discharge lamp and a lighting fixture using the same, in which a decrease in luminous flux of a light emitting portion and unevenness in emission color are prevented.

  The invention of claim 1 includes a loop-shaped bulb formed of a light-transmitting material and filled with a discharge gas, a ferrite core formed of a magnetic material disposed so as to cover a part of the bulb, and a ferrite core And an induction coil that generates a high-frequency electromagnetic field inside the bulb when energized with a high-frequency current, and causes the discharge gas to be excited and emitted by the high-frequency electromagnetic field generated inside the bulb. The long afterglow phosphor layer is formed on the inner wall of the portion of the bulb covered with the ferrite core.

  According to the present invention, a loop-shaped valve and a ferrite core that is arranged so as to cover a part of the valve and is formed of a magnetic material are provided. Since the phosphor layer is formed, it is possible to improve the startability after being stored in a dark place for a long time in a light-off state, and there is a decrease in the luminous flux of the light emitting part on the appearance of the bulb and uneven emission color. It can be prevented from occurring.

  According to a second aspect of the present invention, in the first aspect of the invention, the bulb is divided into a long discharge path region and a short discharge path region by a portion covered with the two ferrite cores, and the long afterglow phosphor. The layer is formed so as to straddle the inner wall of the portion covered with the ferrite core and the inner wall of the short region of the discharge path.

  According to the present invention, the long afterglow phosphor layer is also formed on the inner wall of the short region of the discharge path other than the portion covered with the ferrite core in the bulb. The startability after being stored in can be further improved. In addition, since the long afterglow phosphor layer is formed across the inner wall of the portion covered with the ferrite core and the inner wall of the short region of the discharge path in the bulb, the long afterglow phosphor layer is formed in the bulb. Since it is not necessary to provide a plurality of portions where the light-emitting phosphor layer is formed, the structure of the bulb is simplified, the manufacturing process can be simplified, and the cost can be reduced.

  According to a third aspect of the present invention, the electrodeless discharge lamp according to the first or second aspect is provided.

  According to the present invention, while having a loop-shaped bulb, it has good startability after being stored in a dark place for a long time in a light-off state, and the luminous flux of the light emitting portion on the appearance of the bulb is reduced and the emission color is uneven. It is possible to provide a luminaire including an electrodeless discharge lamp that prevents this.

  According to the first aspect of the present invention, in the electrodeless discharge lamp provided with the loop-shaped bulb, there is an effect that the startability after being stored in a dark place for a long time in the off state can be improved.

  According to invention of Claim 3, in the lighting fixture provided with the electrodeless discharge lamp provided with the loop-shaped bulb | ball, there exists an effect that the startability after storing in a dark place for a long time in a light extinction state can be improved. is there.

(Embodiment 1)
Hereinafter, the electrodeless discharge lamp of this embodiment is demonstrated based on FIGS.

  The electrodeless discharge lamp of the present embodiment, as shown in FIG. 1 (a), is a loop-shaped bulb 1 formed of Pyrex (registered trademark) glass, which is a translucent material, and in which discharge gas is enclosed, Two ferrite cores 2 and 2 that are arranged so as to cover a part of the bulb 1 and formed of a magnetic material, and are wound around a part of each ferrite core 2 and a high-frequency current is supplied from a lighting device 4 described later. Are provided with two induction coils 3 and 3 for generating a high-frequency electromagnetic field inside the bulb 1, and the high-frequency electromagnetic field generated inside the bulb 1 acts on the discharge gas to excite and emit the discharge gas. A discharge path is formed along the bulb 1. In addition, an amalgam (not shown) made of zinc and mercury, which are light emitting materials (ultraviolet light emitting materials), is enclosed in the bulb 1. In addition, the ferrite core 2 arrange | positioned in the form which covers a part of valve | bulb 1 is not limited to two pieces.

  The valve 1 configured as shown in FIG. 1C is manufactured by the following procedure. First, a first tubular body 1a and a second tubular body 1b formed by bending a pipe made of Pyrex (registered trademark) glass into a U shape by bending are produced. Next, a phosphor layer made of a normal white light emitting phosphor is formed on the inner walls of the first tube 1a and the second tube 1b, and the first tube 1a and the second tube 1b are formed. A long afterglow phosphor layer made of a long afterglow phosphor described later is formed only in the vicinity of the junction (see FIG. 1B). And the valve | bulb 1 is produced by joining the 1st pipe body 1a and the 2nd pipe body 1b by the welding process by a gas burner.

Here, as the long afterglow phosphor, a phosphor containing europium and dysprodium co-activated strontium aluminate phosphor (Sr ₄ Al ₁₄ O ₂₅ : Eu, Dy) emitting blue-green is used. ing. The long afterglow phosphor is not limited to the above. Such long afterglow phosphors have a very long afterglow time compared to the above-mentioned normally used phosphors, and the above-mentioned normally used phosphors have a light emission intensity at the time of lighting immediately after turning off. While the time required for attenuation to 1/10 is several tens of msec, in the case of a long afterglow phosphor, the same time is several tens of minutes, which is much longer.

  The first tubular body 1a is formed by bending a Pyrex (registered trademark) glass tube having a diameter of 38 mm and a length of 470 mm into a U shape, and the second tubular body 1b has a diameter of 38 mm and a long length. An 80 mm Pyrex (registered trademark) glass tube is bent into a U shape. Here, the exhaust pipe 14b is connected to the center of the second tubular body 1b. After introducing the above-described discharge gas, the exhaust pipe 14b is sealed from the connecting portion between the narrow tube and the second tubular body 1b leaving only a specified length. Further, the exhaust pipe 14b is also the coldest point of the valve 1, and the fluctuation of the mercury vapor pressure inside the valve 1 can be suppressed by keeping the temperature of the exhaust pipe 14b constant. In addition, the dimension of the glass tube used for the 1st tubular body 1a and the 2nd tubular body 1b is not limited to the above-mentioned value. Further, by enclosing an amalgam (not shown) made of zinc and mercury having a mercury content of 10 mg in the bulb 1 and about 133 Pa (about 1.0 torr) of argon gas which is a discharge gas, The amount of ultraviolet rays generated when mercury vapor in the bulb 1 is excited is maximized.

  Separation in which the phosphor layers 12a and 12b are separated from each other on the inner wall of each of the first tubular body 1a and the second tubular body 1b from the opening ends to a portion on the inner side of 10 mm for welding by a gas burner. Portions 11a and 11b are formed. Here, in the inner wall of the second tubular body 1b, from the end opposite to the both opening ends of the second tubular body 1b in the peeling portion 11b to the portion 10 mm deeper in the tube axial direction, A long afterglow phosphor layer 13b is formed by applying the long afterglow phosphor described above. In addition, the dimension of peeling part 11a, 11b and the dimension of the site | part in which the long persistence fluorescent substance layer 13b was formed are not limited to the above-mentioned dimension.

  The ferrite core 2 is formed in an annular shape having an inner diameter of 42 mm, an outer diameter of 72 mm, and a width of 33 mm. A valve 1 is inserted inside the ferrite core 2. An induction coil 3 is wound around a part of the ferrite core 2. Moreover, each ferrite core 2 covers the site | part in which the peeling part 11a of the 1st tubular body 1a, the peeling part 11b of the 2nd tubular body 1b, and the long persistence fluorescent substance layer 13b in the valve | bulb 1 were formed. Placed in. In addition, the dimension of the ferrite core 2 is not limited to the above-mentioned dimension, as long as it fits the outer diameter of the valve 1 to be inserted.

  The two ferrite cores 2 and 2 are partially wound with the induction coil 3. The induction coil 3 is connected in parallel between the output terminals of the lighting device 4 that outputs a high-frequency current. When a high-frequency current is passed from the lighting device 4 to the induction coil 3, the electrodeless discharge lamp is turned on.

  By the way, in the electrodeless discharge lamp, it is generally necessary that electrons for assisting the start are emitted in the vicinity of the induction coil 3 in the bulb 1 at the start. On the other hand, in the electrodeless discharge lamp of this embodiment, the long afterglow phosphor layer 13b is formed in the vicinity of the induction coil 3 in the inner wall of the bulb 1, and the long afterglow phosphor layer 13b is formed. Since the emission of electrons is promoted by the photoelectric effect due to the afterglow, the electrons for assisting starting can be emitted in the vicinity of the induction coil 3 even after being stored in a dark place for a long time in a light-off state. Actually, as a result of the lighting experiment in the electrodeless discharge lamp having the configuration shown in FIG. 1, the long-afterglow phosphor layer 13b is formed in the dark place after being stored in the dark place in the dark state for 24 hours. It has been confirmed that this is an improvement over electrodeless discharge lamps that are not.

  Further, in the electrodeless discharge lamp of the present embodiment, the light flux and emission color unevenness of the light emitting portion on the external appearance of the bulb 1 are irrespective of whether or not the long afterglow phosphor layer 13b is partially formed. It was confirmed that they were almost the same, and the deterioration of the light emission characteristics due to the provision of the long afterglow phosphor layer 13b did not occur.

  Therefore, in the electrodeless discharge lamp of the present embodiment, the startability in the dark place after being stored in the dark place for a long time in the off state can be improved. In addition, since the entire portion where the long afterglow phosphor layer 13b is formed is covered with the ferrite cores 2 and 2, the luminous flux of the light emitting portion on the appearance of the bulb 1 is reduced and the emission color is uneven. Can be prevented.

  In the electrodeless discharge lamp having the configuration shown in FIG. 1, the portion of the bulb 1 where the long afterglow phosphor layer 13 b is formed is entirely covered with the ferrite core 2. It is not necessary to cover the entire portion where the phosphor layer 13b is formed, and it does not protrude from the portion covered by the ferrite core 2 as long as it does not affect the decrease in luminous flux or uneven emission color in the light emitting portion on the exterior of the bulb 1 It may be. Further, in the electrodeless discharge lamp having the configuration shown in FIG. 1, the two ferrite cores 2 and 2 are arranged at one side in the longitudinal direction of the bulb 1, but the position where the two ferrite cores 2 and 2 are arranged. Is not limited to this. For example, as shown in FIG. 2B, the valve 1 is composed of a first tubular body 1a and a second tubular body 1b having the same size, and peeling portions are provided at both ends of the first tubular body 1a. 11a and the site where the long afterglow phosphor layer 13a is formed are provided, and the site where the peeling portion 11b and the long afterglow phosphor layer 13b are formed are provided at both ends of the second tube 1b. As shown in FIG. 2A, the two ferrite cores 2 and 2 may be arranged at the central portion in the longitudinal direction of the bulb 1. Further, as shown in FIG. 3B, the valve 1 is composed of a U-shaped first tubular body 1a and a second tubular body 1b, and peeling portions are formed at both ends of the first tubular body 1a. 11c and a part where the long afterglow phosphor layer 13c is formed are provided, and a part where the peeling portion 11d and the long afterglow phosphor layer 13d are formed is provided at both ends of the second tube 1b. Further, an exhaust pipe 14b is connected to the first tubular body 1a, and as shown in FIG. 3 (a), two ferrite cores 2 and 2 are connected to both ends of the valve 1 in the longitudinal direction. You may arrange | position to each.

  In the electrodeless discharge lamp described above, an electrodeless discharge lamp that can be used as a fluorescent lamp by providing the bulb 1 in which phosphor layers 12a and 12b made of phosphors that are usually used on the inner wall are formed has been described. However, for example, an electrodeless discharge lamp that includes a bulb 1 made of glass having a high ultraviolet transmittance, has no phosphor layer formed on the inner wall of the bulb 1, and can be used as an ultraviolet lamp. The same effect can be obtained.

(Embodiment 2)
Hereinafter, the electrodeless discharge lamp of this embodiment is demonstrated based on FIG. In addition, the same components as those in the first embodiment are denoted by the same reference numerals and description thereof is omitted.

  As shown in FIG. 1A, the bulb 1 of the electrodeless discharge lamp of the present embodiment is a region corresponding to the first tubular body 1a by a portion of the bulb 1 covered with two ferrite cores 2 and 2. Are divided into a long discharge path region and a short discharge path region corresponding to the second tube 1b. Here, the long afterglow phosphor layer 13b is formed from the inner wall of the portion other than the peeling portion 11b among the portions covered by the ferrite cores 2 and 2 to the inner wall of the short region of the discharge path. That is, in the bulb 1, as shown in FIG. 4A, the long afterglow phosphor layer 13b is formed on the entire inner wall of the region other than the peeling portion 11b in the region corresponding to the second tubular body 1b. Has been. Accordingly, as shown in FIGS. 1B and 1C, the portion where the phosphor layer 12b is formed on the inner wall of the second tubular body 1b and the two portions where the long afterglow phosphor layer 13b is formed. Therefore, the structure of the region corresponding to the second tube 1b of the valve 1 is simplified. Therefore, since the manufacturing process of the bulb 1 is simplified, the cost of the electrodeless discharge lamp can be reduced. In addition, the long afterglow phosphor layer 13b is formed across the inner wall of a portion of the bulb 1 other than the peeling portion 11b in the portion covered with the ferrite cores 2 and 2 from the inner wall of the short region of the discharge path. Therefore, there is an effect that it is possible to improve the startability in the dark place after being stored in the dark place for a long time in the off state in the electrodeless discharge lamp.

  In the electrodeless discharge lamp of the present embodiment, the region corresponding to the second tubular body 1b in the bulb 1 has a decrease in luminous flux and a difference in emission color, but the region corresponding to the second tubular body 1b. Since the length of the discharge path is shorter than the region corresponding to the first tube 1a, the region corresponding to the second tube 1b is the entire bulb 1 compared to the region corresponding to the first tube 1a. The proportion of the light emitting element is small and does not significantly affect the decrease in the luminous flux of the entire light emitting portion on the appearance of the bulb 1 and the unevenness of the light emission color. The long afterglow phosphor described above is more expensive than a normal phosphor, but the region corresponding to the second tubular body 1b where the long afterglow phosphor layer 13b is formed is the entire bulb 1. As the percentage of the total cost is small, there is no significant impact on cost.

  By the way, the emission color of the region corresponding to the second tube 1b in which the long afterglow phosphor layer 13b is formed in the bulb 1 is different from the emission color of the region corresponding to the first tube 1a. There is a concern that unevenness occurs in the emission color of the light emitting portion on the external appearance of the bulb 1.

  On the other hand, in the electrodeless discharge lamp of the present embodiment, a second metal plate (not shown) serving as a light shielding means for shielding light from the region corresponding to the second tubular body 1b of the bulb 1 is used for the second. The light emitted from the region corresponding to the second tubular body 1b is surrounded by the lighting apparatus 20 (see FIG. 5) by surrounding the second tubular body 1b with the lighting apparatus 20 (see FIG. 5). You can avoid going out.

  As a result, while the long afterglow phosphor layer 13b is formed on the entire portion of the bulb 1 excluding the peeling portion 11b in the portion corresponding to the second tube 1b, the emission color on the light emitting portion on the appearance of the bulb 1 is increased. The effect that it can prevent that the nonuniformity arises is acquired.

  Moreover, as a fluorescent substance apply | coated to the whole inner wall except the peeling part 11b in the part corresponded to the 2nd tubular body 1b among the bulb | bulbs 1, it mixes the fluorescent substance normally used and a long persistence fluorescent substance. (For example, a mixture of 5 to 10 wt% of a long persistence phosphor in a commonly used phosphor) may be used. In this case, the emission color of the region corresponding to the second tubular body 1b of the bulb 1 can be brought close to the emission color of the region corresponding to the first tubular body 1a. Accordingly, unevenness in the emission color that occurs in the light emitting portion on the external appearance of the bulb 1 can be suppressed.

(Embodiment 3)
FIG. 5 shows a lighting fixture 20 including the electrodeless discharge lamp described in the first embodiment.

  The lighting fixture 20 of the present embodiment has a U-shaped cross-section having two bent pieces formed by bending both longitudinal ends of a rectangular plate piece in plan view in one direction orthogonal to the plate piece. The main body 21 is provided with the electrodeless discharge lamp and the lighting device 11 shown in the first embodiment housed in the appliance main body 21. As shown in FIG. 5, four couplers 12 are arranged at four locations of the loop-shaped bulb 1 of the electrodeless discharge lamp. Here, the coupler 12 is formed by winding the induction coil 3 (see FIG. 1) around a part of the ferrite core 2 (see FIG. 1). The lighting device 11 is for lighting an electrodeless discharge lamp by supplying a high-frequency current to the induction coil 3, and is electrically connected to the induction coil 3 via an electric wire 23. Further, the other end of the two bent pieces whose one end is continuous with the plate piece in the instrument main body 21 is provided with flange portions 21a and 21a formed so as to protrude away from each other. It is being fixed in the form mounted in the collar part 21a, 21a.

  Thus, although the lighting fixture 20 of the present embodiment includes the loop-shaped bulb 1, it has good startability in the dark place after being stored in the dark place for a long time in a light-off state, and the bulb. There is an effect that it is possible to prevent a decrease in luminous flux of the light emitting portion on the appearance of 1 and unevenness in emission color.

  In addition, what used the electrodeless discharge lamp demonstrated in Embodiment 2 among the lighting fixtures of this embodiment WHEREIN: The light radiated | emitted from the area | region equivalent to the 2nd tubular body 1b among the bulb | bulbs 1 to the fixture main body 21 is used. In order to shield the light, a region corresponding to the second tubular body 1b of the bulb 1 is surrounded by a metal plate (not shown). This prevents unevenness in the emission color from occurring in the light emitting portion on the external appearance of the bulb 1.

The electrodeless discharge lamp of Embodiment 1 is shown, (a) is a plan view, (b) is an exploded plan view of a relevant part, and (c) is a plan view of the relevant part. The other example of a structure of an electrodeless discharge lamp same as the above is shown, (a) is a top view, (b) is a principal part top view. The other example of a structure of an electrodeless discharge lamp same as the above is shown, (a) is a top view, (b) is a principal part top view. It is a principal part top view of the electrodeless discharge lamp of Embodiment 2. The lighting fixture of Embodiment 3 is shown, (a) is a schematic bottom view of the state which removed the glass plate, (b) is a schematic side view. It is the partially broken side view of the electrodeless discharge lamp of a prior art example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Valve | bulb 1a 1st pipe body 1b 2nd pipe body 2 Ferrite core 3 Inductive coil 4 Lighting device 11a, 11b Separation part 12a, 12b Phosphor layer 13b Long persistence fluorescent substance layer 14b Exhaust pipe

Claims (3)

  A loop-shaped bulb formed of a translucent material and filled with a discharge gas, a ferrite core formed of a magnetic material arranged to cover a portion of the bulb, and wound around at least a portion of the ferrite core And an induction coil that generates a high-frequency electromagnetic field inside the bulb when energized with a high-frequency current, and excites and emits a discharge gas by the high-frequency electromagnetic field generated inside the bulb. An electrodeless discharge lamp comprising a long afterglow phosphor layer formed on an inner wall of a portion to be covered.   The bulb is divided into a region having a long discharge path and a region having a short discharge path by two portions covered by the ferrite core, and an inner wall and a discharge path of the portion where the long afterglow phosphor layer is covered by the ferrite core. The electrodeless discharge lamp according to claim 1, wherein the electrodeless discharge lamp is formed across the inner wall of the short region.   A lighting fixture comprising the electrodeless discharge lamp according to claim 1.

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