JP2008053179A - Electrodeless discharge lamp and lighting fixture using it - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electrodeless discharge lamp and a lighting fixture using it without fear of a light output deteriorated even in case of a large rated load. <P>SOLUTION: The lamp comprises a bulb 3 with discharge gas 2 including mercury sealed in, a nearly cylindrical cavity 5 protruded inward in the bulb 3, and a protruded part 6 fitted at a part of the bulb 3 and protruded outside the bulb 3. A permanent magnet 11 of nearly a circular shape is provided covering an outer periphery of the protruded part 6 as a control means for controlling a volume of plasma 13 in the vicinity of the protruded part 6. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an electrodeless discharge lamp and a lighting fixture using the same.

Conventionally, a fluorescent paint in which an electromagnetic field formed by applying a high-frequency current to a coil is applied to a discharge gas filled in a bulb, and ultraviolet rays radiated along with the discharge are applied to the bulb inner surface. There is known an electrodeless discharge lamp that emits light when it is applied to, for example, as disclosed in Patent Document 1. The electrodeless discharge lamp includes a bulb filled with a discharge gas, a coil that generates an electromagnetic field in the bulb, and a raised portion that is formed on the bulb and projects toward the outside of the bulb. When the bulb is turned on with the bulb facing upward, this raised portion becomes a portion where the temperature is lowest on the bulb surface, that is, the coldest point, and controls the mercury vapor pressure in the bulb to an appropriate value. Therefore, the light output of the lamp can be increased.
JP 2001-325920 A

  However, in the above conventional example, when a lamp having a large input power relative to the volume of the bulb, that is, a rated load is large, the mercury vapor pressure becomes too high as necessary because the bulb temperature rises. There was a problem that the output decreased. In addition, since the temperature of the raised portion is designed so that the mercury vapor pressure is optimal when the lamp is fully lit, there is a problem in that the light output decreases due to the temperature of the raised portion being lowered during dimming of the lamp. .

  The present invention has been made in view of the above points, and an object thereof is to provide an electrodeless discharge lamp in which light output does not decrease even when a rated load is large, and a lighting fixture using the same. .

  In order to achieve the above object, the invention of claim 1 accommodates a bulb made of a light-transmitting material and filled with a discharge gas containing mercury, and an induction coil protruding inward of the bulb and energized with a high-frequency current. It has a cavity and a protrusion that is provided at a position substantially opposite to the bulb cavity and protrudes outside the bulb. The discharge gas is ionized by the action of the electromagnetic field formed by the induction coil, and excited light is emitted by the generated plasma. The electrodeless discharge lamp is characterized in that a control means for controlling the amount of plasma in the vicinity of the protrusion is provided.

  The invention of claim 2 is characterized in that, in the invention of claim 1, the discharge gas contains krypton or xenon.

  According to a third aspect of the present invention, in the first or second aspect of the present invention, the control means includes a first induction coil provided on the side close to the protrusion, and a second induction coil provided on the side far from the protrusion, It consists of a high-frequency power source that supplies high-frequency current to the first and second induction coils, and when the projection is turned on vertically upward, the first induction coil is energized and the projection is directed vertically downward. When it is lit, the second induction coil is energized.

  According to a fourth aspect of the present invention, in the first or second aspect of the present invention, the control means includes an auxiliary coil that covers the outer periphery of the protrusion and a high-frequency power source that supplies a high-frequency current to the auxiliary coil. It is characterized by being energized.

  According to a fifth aspect of the present invention, in the first or second aspect of the invention, the control means includes a first induction coil provided on the side close to the protrusion, and a second induction coil provided on the side far from the protrusion, It consists of a high-frequency power source that supplies a high-frequency current to the first and second induction coils, and when the projection is turned on vertically upward, the second induction coil is energized during dimming and the first When the first induction coil is energized and the protrusion is turned on vertically downward, the first induction coil is energized during dimming, and the second induction coil is energized during full lighting. .

  According to a sixth aspect of the present invention, in the first or second aspect of the present invention, the control means includes a first induction coil having a relatively high inductance, a second induction coil having a relatively low inductance, It comprises a high frequency power source that supplies a high frequency current to the second induction coil, and is characterized in that the first induction coil is energized during dimming and the second dielectric coil is energized during full lighting.

  According to a seventh aspect of the present invention, the electrodeless discharge lamp according to any one of the first to sixth aspects, a coupler having an induction coil and mounted with the electrodeless discharge lamp, and a high-frequency current are supplied to the induction coil. A high frequency power supply is provided.

  The invention of claim 8 is an electrodeless discharge lamp according to claim 4, a coupler having an induction coil to which the electrodeless discharge lamp is mounted, a high-frequency power source for supplying a high-frequency current to the induction coil, An instrument body having an opening for taking out light from the electrodeless discharge lamp to the outside, and a cover made of a translucent material attached to the instrument body and covering the opening of the instrument body, One end of the auxiliary coil of the electrodeless discharge lamp is fixed to the cover.

  According to the first aspect of the present invention, the temperature of the protrusion can be adjusted by controlling the amount of plasma in the vicinity of the protrusion, and therefore, the light output can be prevented from decreasing according to the lighting state.

  According to the second aspect of the present invention, since it is heavier than argon that has been widely used as a conventional discharge gas, it is possible to suppress the diffusion of plasma, and therefore, it is possible to suppress the amount of plasma approaching the protrusion. In addition, since the thermal conductivity is smaller than that of argon, it is possible to make it difficult to transfer the heat of plasma to the protrusions.

  According to the third aspect of the present invention, when the projection is turned on vertically upward, the bottom of the bulb can be made the coldest point by generating plasma in the vicinity of the projection. Also, when the projection is turned on vertically downward, the projection can be made the coldest point by generating plasma at a site away from the projection, and in any case, the light output is reduced. Can be prevented.

  According to the fourth aspect of the present invention, plasma can be generated also in the protrusion, and therefore, the temperature of the protrusion during dimming can be maintained by the heat of the plasma, and a decrease in light output can be prevented.

  According to the fifth aspect of the present invention, when the projection is turned on vertically upward, the plasma approaches the bottom of the bulb by supplying a high-frequency current to the second induction coil during dimming and Since the plasma is separated from the bottom of the bulb by supplying a high frequency current to one induction coil, the temperature of the bottom of the bulb can be kept constant. In addition, when the projection is turned on vertically downward, the plasma approaches the projection by supplying a high-frequency current to the first induction coil during dimming, and the high-frequency current is applied to the second induction coil during full lighting. By supplying the plasma, the temperature of the projection can be kept constant because the plasma is separated from the projection. Therefore, a good light output can be obtained in any case.

  According to the invention of claim 6, since high voltage can be generated at both ends of the induction coil during dimming, discharge can be maintained up to low lamp power. In addition, at the time of full lighting, the inductance can be designed to minimize the loss in the induction coil, and thus a good light output can be obtained.

  According to the invention of claim 7, it is possible to realize a lighting fixture that exhibits the effect of any one of claims 1 to 6.

  According to the invention of claim 8, it is possible to realize a lighting fixture having the effect of claim 4. In addition, since one end of the auxiliary coil is fixed to the cover, the auxiliary coil can be easily disposed on the outer periphery of the protrusion by simply attaching the cover to the instrument body.

(Embodiment 1)
Hereinafter, Embodiment 1 of an electrodeless discharge lamp according to the present invention will be described with reference to the drawings. In the present embodiment, as shown in FIG. 1A, a substantially bulb-shaped bulb 3 in which a discharge gas 2 containing mercury is enclosed, and a substantially cylinder that is sealed by the bulb 3 and protrudes inward of the bulb 3. Of the protrusion 6 as a control means for controlling the amount of the plasma 13 in the vicinity of the protrusion 6. A substantially annular permanent magnet 11 covering the outer periphery is provided.

  The bulb 3 is obtained by processing a transparent material such as glass into a substantially light bulb shape, and a projection 6 that protrudes toward the outside of the bulb 3 is provided on the top of the bulb 3 in FIG. The protective film 3a and the phosphor film 3b (only a part in the drawing) are applied to the inner surfaces of the bulb 3 and the protrusion 6. Further, a base 8 a for fitting the valve 3 and a coupler 8 described later is attached to the upper end of the valve 3 in FIG. 1A (hereinafter referred to as “the bottom of the valve 3”).

  An exhaust pipe 7 formed in a substantially cylindrical shape is welded to the cavity 5 from the upper bottom in FIG. 1A toward the lower opening. An amalgam 1 for evaporating mercury and ensuring a mercury vapor pressure necessary for lighting is enclosed inside the exhaust pipe 7. In addition, the amalgam 1 of this embodiment is an alloy of zinc (Zn) and mercury (Hg). Further, the protective film 3 a and the phosphor film 3 b (only a part in the drawing) are applied to the outer surface of the cavity 5 in the same manner as the inner surfaces of the bulb 3 and the protrusion 6.

  The coupler 8 holds the bulb 3 and positions the induction coil 4 with respect to the bulb 3. The induction coil 4 that generates a high-frequency electromagnetic field and excites the discharge gas 2 when supplied with high-frequency power, and an induction It consists of a core 9 around which the coil 4 is wound, and a heat conductor 10 that radiates heat generated by the induction coil 4 and the core 9. The heat conductor 10 is formed in a substantially cylindrical shape using a metal having a good heat conductivity such as aluminum, and the upper end thereof extends in the radial direction. The heat conductor 10 is inserted into the cavity 5, and the exhaust pipe 7 is inserted through the heat conductor 10. The core 9 is attached to the side surface on the lower end side of the heat conductor 10. The core 9 is obtained by processing a Mn—Zn ferrite material having good high-frequency magnetic characteristics into a substantially cylindrical shape. On the side surface of the core 9, an induction coil 4 that is energized with a high-frequency current from a high-frequency power source 14 and generates a high-frequency electromagnetic field in the valve 3 is wound through an insulating layer (not shown).

  As shown in FIG. 1B, the high frequency power source 14 is connected to a base 8a fitted with the coupler 8 via an output line 15, and the induction coil 4 of the coupler 8 is connected via the base 8a. In addition to supplying a high frequency current, the input power to the induction coil 4 is adjusted by intermittently changing the operating frequency.

  In the above configuration, when a high frequency current is passed through the induction coil 4, a high frequency electromagnetic field is generated around the induction coil 4. Electrons in the bulb 3 are accelerated by the high-frequency electromagnetic field, and the discharge gas 2 is ionized by the collision of the electrons to generate plasma 13. When the plasma 13 is generated, mercury atoms in the amalgam 1 are excited, and the excited mercury atoms emit ultraviolet light having a wavelength of 254 nm when returning to the ground state. The ultraviolet rays are converted into visible light in the phosphor film 3b applied to the inner surfaces of the bulb 3 and the protrusion 6 and the outer surface of the cavity 5, and are transmitted through the bulb 3 and emitted to the outside.

  Normally, the bulb 3 becomes hot due to the heat of the plasma 13 during lighting. Therefore, the mercury vapor pressure is lowered by setting the protrusion 6 as the coldest point, but the input power is large with respect to the volume of the bulb 3. That is, when the rated load is large, it is not sufficient to provide the protrusion 6. Therefore, when the permanent magnet 11 is provided on the outer periphery of the protrusion 6 as described above, electrons in the plasma 13 spirally move along the magnetic force lines generated from the permanent magnet 11 so that the plasma 13 does not approach the protrusion 6. can do. For this reason, suppressing the amount of the plasma 13 in the vicinity of the protrusion 6 prevents the temperature of the protrusion 6 from becoming unnecessarily high. Therefore, even when the rated load is large, the light output does not decrease and a good light output is achieved. Obtainable. In the present embodiment, one protrusion 6 and one permanent magnet 11 are provided on the valve 3, but they may be provided at a plurality of locations.

  By the way, although argon is used as the discharge gas 2 in this embodiment, xenon or krypton may be used instead of argon. Since xenon and krypton are heavier than argon, the plasma 13 is difficult to diffuse. Therefore, the amount of the plasma 13 approaching the protrusion 6 can be suppressed. Further, since the thermal conductivity is smaller than that of argon, it is possible to make it difficult for the heat of the plasma 13 to be transmitted to the protrusion 6.

(Embodiment 2)
Hereinafter, Embodiment 2 of the electrodeless discharge lamp according to the present invention will be described with reference to the drawings. However, since the basic configuration of the present embodiment is the same as that of the first embodiment, the same parts as those of the first embodiment are denoted by the same reference numerals and description thereof is omitted. In the present embodiment, as shown in FIG. 2A, the first induction coil 4a provided on the side close to the protrusion 6 as a control means and the second induction coil 4a provided on the side away from the protrusion 6 are provided. The induction coil 4b is wound around the outer surface of the core 9, and when the projection 6 is lit up, the first induction coil 4a is lit and the projection 6 is lit down. In this case, a high frequency current is supplied from the high frequency power supply 14 to the second induction coil 4b. In the present embodiment, the first induction coil 4a and the second induction coil 4b constituting the control means are also used as the induction coil of the coupler 8.

  With the above configuration, when the projection 6 is lit upward, the plasma 13 is generated in the vicinity of the first induction coil 4a close to the projection 6, so that the bottom of the bulb 3 is the coldest spot. Thus, the mercury vapor pressure can be lowered (see FIG. 2A). Further, when the projection 6 is turned on downward, the plasma 13 is generated in the vicinity of the second induction coil 4b, so that the projection 6 becomes the coldest point and the mercury vapor pressure can be lowered. (See FIG. 2 (b)). Therefore, a good light output can be obtained in any case.

(Embodiment 3)
Hereinafter, Embodiment 3 of the electrodeless discharge lamp according to the present invention will be described with reference to the drawings. However, since the basic configuration of the present embodiment is the same as that of the first embodiment, the same parts as those of the first embodiment are denoted by the same reference numerals and description thereof is omitted. In the present embodiment, as shown in FIG. 3, an auxiliary coil 12 made of a solenoid is wound around the outer periphery of the protrusion 6 instead of the permanent magnet 11 of the first embodiment as a control means, and the induction coil 4, a high-frequency current is supplied from the high-frequency power source 14 to the auxiliary coil 12.

  Normally, when the temperature of the projection 6 is designed so that the mercury vapor pressure is optimal when all the lights are on, the input power from the high-frequency power source 14 becomes smaller than that when all the lights are on during dimming. Although the temperature of the portion 6 is excessively lowered, if the above configuration is used, an electromagnetic field is generated by supplying a high-frequency current to the auxiliary coil 12 during dimming, and the plasma 13 is also generated in the protrusion 6. Therefore, the temperature of the protrusion 6 can be kept optimal by the heat of the plasma 13, and a good light output can be obtained even during dimming.

  By the way, as shown in FIG. 4, a substantially bowl-shaped instrument body 16 having an open lower surface for housing an electrodeless discharge lamp, and a substantially transparent material attached to the instrument body 16 and covering the opening of the instrument body 16. You may apply this embodiment to the lighting fixture comprised with the circular cover 17. FIG. In this case, if one end of the auxiliary coil 12 of the present embodiment is fixed to the cover 17 in advance, the auxiliary coil 12 can be easily disposed on the outer periphery of the protrusion 6 simply by attaching the cover 17 to the instrument body 16. .

(Embodiment 4)
Hereinafter, an electrodeless discharge lamp according to a fourth embodiment of the present invention will be described with reference to the drawings. However, since the basic configuration of this embodiment is the same as that of the second embodiment, the same parts as those of the second embodiment are denoted by the same reference numerals and the description thereof is omitted. The present embodiment has exactly the same configuration as the electrodeless discharge lamp of the second embodiment, and includes first and second induction coils 4a and 4b as control means, and a high-frequency current is supplied to the first induction coil 4a during dimming. The high frequency current is supplied to the second induction coil 4b at the time of full lighting. In the present embodiment, the first induction coil 4a and the second induction coil 4b constituting the control means are also used as the induction coil of the coupler 8.

  When configured as described above, the plasma 13 is generated on the side close to the protrusion 6 at the time of dimming, so that the temperature of the protrusion 6 can be raised, which is lower than that at the time of full lighting (FIG. 5A). )reference). In addition, since the plasma 13 is generated on the side away from the protrusion 6 when fully lit, it is possible to suppress an increase in the temperature of the protrusion 6 where the temperature is higher than that during dimming (see FIG. 5B). . Therefore, the temperature of the protrusion 6 can be kept constant both during dimming and during full lighting, and a good light output can be obtained.

  In the present embodiment, the case where the coldest point is the protrusion 6, that is, the case where the protrusion 6 is turned on downward is described. However, the case where the coldest point is the bottom of the bulb 3, that is, the protrusion In the case of lighting with 6 facing upward, the same effect as described above can be obtained if a high-frequency current is supplied to the second induction coil 4b during dimming and the first induction coil 4a during full lighting. it can.

(Embodiment 5)
Hereinafter, Embodiment 5 of the electrodeless discharge lamp according to the present invention will be described with reference to the drawings. However, since the basic configuration of this embodiment is the same as that of the second embodiment, the same parts as those of the second embodiment are denoted by the same reference numerals and the description thereof is omitted. In the present embodiment, as shown in FIG. 6A, the first core 9a having a relatively high magnetic permeability and the second core 9b having a relatively low magnetic permeability are arranged in the axial direction of the coupler 8 (same as in FIG. The first induction coil 4a having a relatively high inductance is disposed on the outer surface of the first core 9a as the control means, and the inductance is disposed on the outer surface of the second core 9b. The second induction coil 4b having a relatively low is wound around each. Further, the first induction coil 4a and the first core 9a are disposed on the side close to the protrusion 6, and the second induction coil 4b and the second core 9b are disposed on the side away from the protrusion 6. It is installed. In the present embodiment, the first induction coil 4a and the second induction coil 4b constituting the control means are also used as the induction coil of the coupler 8.

  With the above configuration, a high voltage can be generated in the induction coil 4a by supplying a high-frequency current to the first induction coil 4a having a relatively high inductance at the time of dimming. Can be maintained (see FIG. 6A). Further, by supplying a high-frequency current to the second induction coil 4b having a relatively low inductance at the time of full lighting, the loss can be reduced as compared with the case where the induction coil 4 is used. Can be obtained (see FIG. 6B).

It is a figure which shows the electrodeless discharge lamp of Embodiment 1 of this invention, (a) is sectional drawing, (b) is a perspective view including a high frequency power supply. It is a figure which shows the electrodeless discharge lamp of Embodiment 2 of this invention, (a) is sectional drawing when a projection part is arrange | positioned vertically upward, (b) is a case where a projection part is arrange | positioned vertically downward It is sectional drawing. It is sectional drawing which shows the electrodeless discharge lamp of Embodiment 3 of this invention. It is sectional drawing which shows the lighting fixture using the electrodeless discharge lamp same as the above. It is a figure which shows the electrodeless discharge lamp of Embodiment 4 of this invention, (a) is sectional drawing at the time of light control, (b) is sectional drawing at the time of all lighting. It is a figure which shows the electrodeless discharge lamp of Embodiment 5 of this invention, (a) is sectional drawing at the time of light control, (b) is sectional drawing at the time of full lighting.

Explanation of symbols

1 Amalgam 2 Discharge gas 3 Valve 4 Induction coil 5 Cavity 6 Projection

Claims (8)

  A bulb made of a light-transmitting material and filled with a discharge gas containing mercury, a cavity that houses an induction coil that protrudes inward from the bulb and is energized with a high-frequency current, and is provided at a position substantially opposite the bulb cavity. An electrodeless discharge lamp having a projection protruding outside the bulb, ionizing discharge gas by the action of an electromagnetic field formed by an induction coil, and exciting and emitting light by the generated plasma. An electrodeless discharge lamp comprising a control means for controlling the amount.   The electrodeless discharge lamp according to claim 1, wherein the discharge gas contains krypton or xenon.   The control means includes a first induction coil provided on the side close to the protrusion, a second induction coil provided on the side far from the protrusion, and a high frequency that supplies a high frequency current to the first and second induction coils. When the projection is turned on vertically upward, the first induction coil is energized. When the projection is turned on vertically downward, the second induction coil is energized. The electrodeless discharge lamp according to claim 1 or 2, characterized in that:   3. The control device according to claim 1, wherein the control means includes an auxiliary coil that covers the outer periphery of the protrusion and a high-frequency power source that supplies a high-frequency current to the auxiliary coil, and energizes the auxiliary coil during dimming. Electrode discharge lamp.   The control means includes a first induction coil provided on the side close to the protrusion, a second induction coil provided on the side far from the protrusion, and a high frequency that supplies a high frequency current to the first and second induction coils. When the projection is turned on vertically upward, the second induction coil is energized during dimming, the first induction coil is energized during full lighting, and the projection is directed vertically downward. 3. The electrodeless discharge lamp according to claim 1, wherein when the light is lit, the first induction coil is energized during dimming, and the second induction coil is energized when fully lit.   The control means includes a first induction coil having a relatively high inductance, a second induction coil having a relatively low inductance, and a high-frequency power source that supplies a high-frequency current to the first and second induction coils. 3. The electrodeless discharge lamp according to claim 1, wherein the first induction coil is energized during dimming, and the second dielectric coil is energized during full lighting.   An electrodeless discharge lamp according to any one of claims 1 to 6, a coupler having an induction coil and mounted with the electrodeless discharge lamp, and a high-frequency power source for supplying a high-frequency current to the induction coil. Lighting equipment characterized by 5. An electrodeless discharge lamp according to claim 4, a coupler having an induction coil to which the electrodeless discharge lamp is mounted, a high frequency power source for supplying a high frequency current to the induction coil, and a shape surrounding the electrodeless discharge lamp. An auxiliary coil for an electrodeless discharge lamp, comprising: an instrument body having an opening for extracting light from the electrode discharge lamp to the outside; and a cover made of a translucent material attached to the instrument body and covering the opening of the instrument body One end of the lighting fixture is fixed to the cover.

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