JP2006269211A - Electrodeless discharge lamp and luminaire comprising the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To ensure a desired coldest-spot temperature in a bulb in an electrodeless discharge lamp or a luminaire comprising the same so as to ensure a predetermined vapor pressure of mercury irrespective of whether the lighting direction of the lamp is upward or downward. <P>SOLUTION: In the electrodeless discharge lamp, the bulb has a concave cavity to which a coupler for generating an induction electric field in an airtight container is to be fitted, so that a discharge gas is excited to emit light by the action of an electromagnetic field. A metallic part 17 to touch the bulb is provided at a portion of a base 15 that is made of resin and holds the bulb, the coupler being fitted to the base 15. It is thereby possible to ensure a predetermined coldest-spot temperature even in the case of base-down lighting and to obtain a constant light output irrespective of lighting direction. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an electrodeless discharge lamp that discharges a discharge gas by causing a high-frequency electromagnetic field formed by an induction coil to act on the discharge gas without having an electrode in a bulb in which the discharge gas is sealed, and a lighting apparatus including the same. .

  Conventionally, a straight tubular or round tubular low pressure discharge fluorescent lamp in which electrodes are arranged at both ends is widely known as a general household lighting fixture. These fluorescent lamps discharge in the bulb by enclosing mercury and a rare gas in the bulb and supplying electrons from the electrodes. Ultraviolet rays emitted from mercury atoms excited by electric discharge are converted into visible light by a phosphor.

  In addition, low-pressure discharge fluorescent lamps are widely used as backlights for liquid crystal displays, but in contrast to general household fluorescent lamps that use thermal electrons emitted by heating electrodes, backlights are used. Many of the low-pressure discharge fluorescent lamps for use are cold cathode types that do not heat the electrodes.

  On the other hand, an electrodeless discharge lamp as disclosed in Patent Document 1, Patent Document 2, Patent Document 3, and Patent Document 4 described below is known. This electrodeless discharge lamp excites the discharge gas by applying a high-frequency electromagnetic field to the discharge gas sealed in the outer bulb, and the emitted ultraviolet light is visible by the phosphor applied to the inner surface of the outer bulb. It is converted into and emits light. Since this electrodeless discharge lamp does not have an electrode inside, it does not turn off due to electrode wear, has a longer life than a general fluorescent lamp, and is small in size and high output.

  Among these, the electrodeless discharge lamps disclosed in Patent Document 1 and Patent Document 2 have a high light output over a wide range even if the ambient temperature changes with respect to the light output at an ambient temperature of 25 ° C. As obtained, bismuth-indium amalgam is used as the encapsulating material.

  In order to realize a high light output relative to the light output during stable lighting, it is necessary to ensure a high mercury vapor pressure. When using bismuth-indium amalgam, for example, it takes about one minute to secure 60% light output with respect to light output during stable lighting. This corresponds to the time required for the temperature of the bismuth-indium amalgam to reach the temperature required to supply mercury. That is, such a ramp has a slow rise time.

  For such a problem, the lamp disclosed in Patent Document 3 uses mercury droplets. According to this lamp, it is stated that 50% of the maximum output is reached within 2-3 seconds after the lamp is started. However, since this lamp uses mercury droplets, it is difficult to control the amount of sealing. We want to minimize the amount of mercury because it protects the environment and blocks light output when it adheres to the phosphor surface. However, since mercury is consumed in the long-term use of the lamp by forming an alloy with sodium or becoming an oxide, we want to enclose a certain amount or more. In other words, the control of the amount enclosed is extremely important for maintaining lamp performance. When amalgam is used, the change in light output is small with respect to the change in ambient temperature as described above. However, when mercury droplets are used, the vapor pressure of mercury changes greatly with respect to the change in ambient temperature. This greatly affects the light output. Therefore, when using mercury droplets, it is necessary to manage the temperature of the coldest part (the point at which the temperature is lowest on the surface of the bulb) that controls the vapor pressure of mercury. The temperature is in the range of about 35 to 45 ° C.

  Furthermore, mercury in the bulb may peel off the phosphor by moving in the bulb when the lamp vibrates, etc.In addition, when manufacturing the lamp, in order to increase the degree of vacuum in the bulb, After heating the lamp, mercury will be sealed, but when the mercury droplets are sealed, if the desired amount of mercury cannot be sealed due to evaporation, or the enclosed mercury evaporates in the lamp, the lamp surface will become blackened. There are problems such as being observed.

In addition, when realizing a lamp with low power consumption, the volume of the bulb is small, and the volume of discharge is relatively large with respect to the size of the bulb, so the temperature of the coldest part is kept constant regardless of the lighting direction. It becomes difficult to keep. Therefore, the temperature control of the bulb protrusion when the base is turned on with the base down can be controlled by changing the diameter and height of the protrusion, but the neck portion when the base is down with the base upward. Temperature control becomes a problem.
JP 7-272688 A Japanese Utility Model Publication No. 6-5006 JP 2001-325920 A Japanese Patent Application No. 2004-162510

  The present invention has been made to solve the above-described problems, and realizes a lamp having a high light output regardless of the lighting direction of the lamp, that is, a predetermined vapor pressure of mercury irrespective of the lighting vertical direction. Therefore, it is an object of the present invention to provide an electrodeless discharge lamp capable of securing a desired coldest spot temperature in a bulb and a lighting fixture including the same.

In order to achieve the above-mentioned object, the present invention includes a bulb formed by sealing a discharge gas and mercury controlled at the coldest point temperature in an airtight container formed of a light-transmitting material, and is formed by an induction coil. In an electrodeless discharge lamp that excites and emits a discharge gas by the action of an electromagnetic field, the coupler is fitted, and a metal part that contacts the bulb is provided in a part of a base made of a resin that holds the bulb. is there.
Moreover, the said metal part shall be fin shape, and the longitudinal direction shall shall be substantially orthogonal to the winding direction of a coil.
Further, the valve contact surface of the metal part may be substantially parallel to the coil winding direction.
Moreover, the said metal part is a metal pin inserted from the outer side of a nozzle | cap | die, Comprising: The protrusion in the front-end | tip can be fitted with the recessed part of a valve | bulb.
Further, the metal part may be an exhaust pipe breakage preventing guide provided on the inner surface of the base.
Moreover, this invention is a lighting fixture provided with the said lamp | ramp, the coupler with which the said lamp | ramp is mounted | worn, and the lighting circuit electrically connected to the said coupler.

  According to the electrodeless discharge lamp and the lighting fixture of the present invention, the base-up lighting is of course achieved by providing a metal part that contacts the bulb in a part of the base made of resin that holds the bulb and fits with the coupler. Even in base-down lighting, a predetermined coldest spot temperature can be secured, and a constant light output can be obtained regardless of the lighting direction.

  Hereinafter, an electrodeless discharge lamp according to various embodiments of the present invention and a lighting fixture including the lamp will be described with reference to the drawings.

(Embodiment 1)
FIG. 1 shows an electrodeless discharge lamp according to Embodiment 1, and FIG. 2 shows details of a cap portion of the lamp. The electrodeless discharge lamp includes a bulb 1 in which a discharge gas is sealed in an airtight container 23 formed of a translucent material. The valve 1 includes a concave cavity 5 into which a coupler 26 (indicated by a two-dot chain line in the figure) composed of an induction coil for generating an induction electric field and a ferrite core is fitted, and a cavity 5 from the bottom of the cavity 5. An exhaust narrow tube 8 is formed in the inside toward the opening. The airtight container 23 serving as a discharge space is formed by sealing the cavity 5 in which the exhaust thin tube 8 is welded to the bulb 1.

  In the bulb 1, the protective film 2 and the phosphor film 3 are applied to the inner wall of the airtight container 23. A protective film 6 and a phosphor film 7 are applied to the peripheral wall of the cavity 5 (only a part is shown in the figure). A projection 4 is provided on the top of the bulb 1. The vicinity of the bottom of the valve 1 is a valve neck portion 14 to which a base 15 made of a resin material is attached. The lower end portion of the valve 1 is a sealing portion 11 of the cavity 5. In the present invention, a radiating fin is provided as a metal portion 17 in contact with the valve 1 in a part of the base 15 made of resin that holds the valve 1 and is fitted with the coupler 26 (not shown in FIG. 1). The metal portion 17 has a longitudinal direction substantially orthogonal to the coil winding direction and is in thermal contact with the heat radiating plate 16. By fitting the coupler 26 into the cavity 5 of the bulb 1, a lighting fixture is configured.

  FIG. 6 shows a configuration when the lighting fixture is configured. FIG. 6 shows a fifth embodiment which will be described later. Here, FIG. The coupler 26 is connected with a lighting circuit 25 for supplying a high-frequency current through a tube lamp line 24. When the coupler 26 is fitted into the cap 15 of the bulb 1, the coupler 26 is fitted into the cavity 5, and the discharge gas sealed in the hermetic container 23 is discharged by the action of an electromagnetic field formed by an induction coil provided in the coupler 26. Excitation light is emitted. The coupler 26 and the base 15 are fixed to the heat sink 16.

  The valve 1 will be described in further detail. A rare gas such as argon or krypton is accommodated in the hermetic container 23 of the valve 1, and the total amount for releasing mercury is approximately 17 mg in a weight ratio of 50:50 in the exhaust narrow tube 8 facing the cavity 5. A metal container 13 made of an iron-nickel alloy, in which Zn-Hg amalgam is sealed, is inserted. A glass rod 12 for determining the position of the metal container 13 is disposed in the exhaust thin tube 8. The exhaust thin tube 8 is provided with a recess 9 and a tip-off portion 10.

  In a lighting fixture in which such a bulb 1 is fitted to the coupler 26, when a high-frequency current is passed through the induction coil, a high-frequency electromagnetic field is generated around the induction coil. Since the high-frequency current passed through the induction coil has a low frequency of several hundred kHz, a ferrite core magnetic core is provided inside the induction coil. Electrons in the hermetic container 23 are accelerated by the high-frequency electromagnetic field, and the gas is ionized by the collision of electrons to generate a discharge. During the discharge, the noble gas is excited, and the excited atoms generate ultraviolet rays when returning to the ground state. This ultraviolet light is converted into visible light by the phosphor film 3 applied to the inner wall of the bulb 1 and the phosphor film 7 applied to the peripheral wall of the cavity 5. The converted visible light passes through the bulb 1 and is emitted to the outside.

  Note that a metal oxide such as Al2O3 is used as the phosphor binder, and the phosphor film 7 in the cavity 5 is protected by increasing the amount of addition thereof, thereby preventing deterioration of the phosphor. The metal oxide used as the binder may be Y2O3 or MgO in addition to Al2O3.

  In the lamp configured as described above, the bulb neck portion is formed by providing the metal portion 17 that contacts the bulb 1 in a part of the base 15 made of resin that holds the bulb 1 and is fitted to the coupler 26. 14 heat can be transmitted to the heat sink 16 and the outside, thereby lowering the temperature of the valve neck 14, the valve neck 14 becomes the coldest part in the base-down lighting, and the protrusion in the base-up lighting. No. 4 became the coldest part, and it was confirmed that the coldest spot temperature of the lamp had almost no difference depending on the lighting direction.

  In addition, this result shows a case where the projection 4 of the bulb 1 has an opening diameter d of 10 mm and a depth H of 10 mm. Various lamps having an opening diameter d of up to 15 mm and a depth of up to 15 mm were made as prototypes, and the temperature and light output of the bulb 1 were measured. As a result, similar effects were confirmed.

(Embodiment 2)
FIG. 3 shows a base part of the electrodeless discharge lamp of the second embodiment. In order to confirm the effect of the shape of the metal part 17 in contact with the valve 1, the configuration shown in the second embodiment was examined. In the second embodiment, the valve contact surface 18 of the fin-shaped metal portion 17 is substantially parallel to the coil winding direction. Other configurations are the same as those of the first embodiment.

  The electrodeless discharge lamp configured as described above was manufactured, and the coldest spot temperature and light output of the bulb 1 were measured. As a result, it was confirmed that the coldest spot portion of the bulb 1 spreads but the light output did not change. That is, it is possible to perform lighting with almost no change in light output depending on the lighting direction. However, if the bulb contact surface 18 of the metal portion 17 makes one turn in the winding direction of the bulb 1, an induction current is generated in the metal portion 17 and the lamp is extinguished. Therefore, the length in the winding direction is the bulb neck. It is necessary to make it shorter than the length of the part 14.

(Embodiment 3)
FIG. 4 shows a base part of the electrodeless discharge lamp of the third embodiment. In the third embodiment, the metal portion 17 is not a fin shape (unlike the first and second embodiments), and is a metal pin 20 inserted from the outside of the base 15, and a protrusion 21 at the tip thereof. It was supposed to be fitted with the recess 19 of the valve 1. Other configurations are the same as those of the first embodiment.

  When the electrodeless discharge lamp configured as described above was manufactured and the coldest spot temperature and light output of the bulb 1 were measured, the coldest spot of the bulb 1 was in contact with the protrusion 21 at the tip of the metal pin 20. Thus, the lighting can be performed with almost no change in the light output depending on the lighting direction. As the number of protrusions 21 at the tip of the metal pin 20 increases, the number of coldest spot temperatures increases and a stable coldest spot temperature can be secured. However, if the number of protrusions 21 is too large, the structure becomes complicated.

(Embodiment 4)
FIG. 5A, FIG. 5B, and FIG. 5C show various examples of the electrodeless discharge lamp according to the fourth embodiment. In these examples, the function of the metal portion 17 is provided to the exhaust pipe break prevention guides 22a, 22b, and 22c (generally 22) provided on the inner surface of the base 15. The guide 22 is provided on the inner surface of the base 15 to prevent the exhaust thin tube 8 from being broken when the coupler is inserted. When the coupler is attached to the valve 1, the tip of the coupler first comes into contact with the guide 22. The guide 22 has a certain length, and even when the coupler and the axis of the valve 1 are misaligned, if the coupler is inserted along the guide 22, the tip of the exhaust thin tube 8 can be prevented from being broken. it can.

  In the example of FIG. 5 (a), the guide 22a is made of resin and partially uses metal, contacts the lamp sealing portion 11 near the opening of the cavity 5, and is further disposed on the outer periphery of the base 15. It is in thermal contact with the heat radiating plate 16 and conducts heat of the lamp.

  In the example of FIG. 5B, for the purpose of simplifying the structure of the base 15, the guide 22 b is entirely made of metal and has the same effect as the guide 22 a by contacting the vicinity of the opening of the cavity 5. It is supposed to fulfill.

  In the example of FIG. 5C, for the purpose of further simplifying the structure of the base 15, the guide 22 c is entirely made of metal, forms the bottom surface of the base 15, and increases the contact area with the radiator plate 16. This increases the heat dissipation effect.

  When an electrodeless discharge lamp having the guides 22a, 22b, and 22c configured as described above is manufactured and the coldest spot temperature and light output of the bulb 1 are measured, the coldest spot of the bulb 1 is in the vicinity of the sealing portion 11. Thus, it is possible to perform lighting with almost no change in light output depending on the lighting direction.

(Embodiment 5)
FIG. 6 shows a luminaire as a fifth embodiment. The electrodeless discharge lamp of the lighting fixture is the one described in the first to fourth embodiments, and the base 15 used in each embodiment is attached to the lamp. The coupler 26 is electrically connected to the lighting circuit 25 through the tube lamp line 24. In various lighting fixtures equipped with these lamps, couplers 26, and lighting circuits 25, the coldest spot temperature and light output of the bulb 1 were measured. The coldest spot of the bulb 1 was described in the first to fourth embodiments. A predetermined temperature can be ensured at the site, and lighting can be performed with almost no change in light output depending on the lighting direction.

  The present invention is not limited to the configuration of the above embodiment, and various modifications can be made without departing from the spirit of the invention.

1 is a schematic cross-sectional view of an electrodeless discharge lamp according to an embodiment of the present invention. The perspective view which shows the nozzle | cap | die part of the lamp | ramp by Embodiment 1 of this invention. The perspective view which shows the nozzle | cap | die part of the lamp | ramp by Embodiment 2 of this invention. The fragmentary sectional view of the lamp | ramp by Embodiment 3 of this invention. The fragmentary sectional view which shows an example of Embodiment 4 of this invention. The fragmentary sectional view which shows the other example of Embodiment 4 of this invention. The fragmentary sectional view which shows the other example of Embodiment 4 of this invention. The perspective view of the lighting fixture by Embodiment 5 of this invention.

Explanation of symbols

1 Bulb (lamp)
5 Cavity 8 Exhaust narrow tube 14 Valve neck 15 Base 17 Metal part (radiating fin)
18 Valve Contact Surface 19 Valve Recess 20 Metal Pin 21 Metal Pin Projection 22a, 22b, 22c Exhaust Thin Tube Breaking Prevention Guide 23 Airtight Container 24 Tube Light Line 25 Lighting Circuit

Claims (6)

A valve formed by sealing discharge gas and mercury controlled at the coldest point temperature in an airtight container formed of a translucent material is provided, and the discharge gas is excited and emitted by the action of an electromagnetic field formed by an induction coil. In electrodeless discharge lamps,
An electrodeless discharge lamp, wherein a metal portion that contacts the bulb is provided in a part of a base made of a resin that holds the bulb and to which the coupler is fitted.   The electrodeless discharge lamp according to claim 1, wherein the metal part has a fin shape, and a longitudinal direction thereof is substantially orthogonal to a winding direction of the coil.   3. The electrodeless discharge lamp according to claim 2, wherein a bulb contact surface of the metal part is substantially parallel to a winding direction of the coil.   2. The electrodeless discharge lamp according to claim 1, wherein the metal part is a metal pin inserted from the outside of the base, and a protrusion at the tip of the metal part is fitted to a recessed part of the bulb.   2. The electrodeless discharge lamp according to claim 1, wherein the metal part is a guide for preventing an exhaust tube breakage provided on an inner surface of the base.   7. A lighting fixture comprising: the lamp according to claim 1; a coupler fitted to the lamp; and a lighting circuit electrically connected to the coupler.

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