JP2008053178A - Electrodeless discharge lamp and lighting device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electrodeless discharge lamp which ensures a mercury vapor pressure within a valve and a lighting device using the same. <P>SOLUTION: A lighting device comprises an electrodeless discharge lamp 1 having a valve 3 composed of translucent materials and filled with rare gas and amalgam, and a coupler 2 wound with an inductive coil 4. A storage concave 31 is formed on an external surface of the valve 3 to house the inductive coil 4, and an exhaust convex 32 to be inserted into the coupler 2 is projected at the bottom of the storage concave 31. An amalgam container 5 storing amalgam is positioned in the exhaust convex 32 with a shift to the insertion side of the coupler 2 into the storage concave 31 rather than the inductive coil 4. The amalgam container 5 is positioned in a location with a relatively high temperature to ensure a mercury vapor pressure within the valve 3. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

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

  Conventionally, as shown in FIG. 7, an electrodeless discharge lamp apparatus including an electrodeless discharge lamp 1 having a bulb 3 made of a translucent material and filled with a discharge gas, and an induction coil 4 disposed in the vicinity of the bulb 3. Is provided (for example, refer to Patent Document 1).

  7 will be described in detail with reference to FIG. 7. In this electrodeless discharge lamp device, the bulb 3 has an opening in the lower surface and a storage recess 31 having a depth direction in the vertical direction. Have. A space (hereinafter referred to as “discharge space”) 30 in which the discharge gas is enclosed in the bulb 3 includes the entire circumference of the storage recess 31 viewed from the depth direction of the storage recess 31 and the outer bottom surface side of the storage recess 31. And is formed continuously. The induction coil 4 is wound around the outer periphery of the cylindrical coupler 2 and is disposed close to the valve 3 by inserting the coupler 2 into the housing recess 31.

  The electrodeless discharge lamp 1 has a light bulb shape as a whole, and has a ring-shaped base 10 surrounding the opening of the housing recess 31. The coupler 2 includes a cylindrical main body 21 that is inserted into the storage recess 31 and a pedestal 22 that protrudes from the main body 21 when viewed from above. The electrodeless discharge lamp 1 is mechanically held with respect to the coupler 2 by fitting the pedestal 22 of the coupler 2 into a recess provided on the lower surface of the base 10, for example. A part of the main body 21 of the coupler 2 is constituted by a cylindrical ferrite core 21a, and the induction coil 4 is wound around the portion constituted by the ferrite core 21a in the main body 21, and the ferrite core 21a is induced. It protrudes above and below the coil 4. Parts other than the ferrite core 21a of the coupler 2 are also made of a material having a relatively high thermal conductivity, and the coupler 2 also has a function of radiating heat generated in the induction coil 4.

  Further, in the bulb 3, an exhaust projection 32 that protrudes downward from the bottom of the housing recess 31 and has a cavity communicating with the discharge space 30 and is inserted into the main body 21 of the coupler 2.

  A metal amalgam container 5 in which amalgam (not shown) is accommodated is accommodated in the exhaust projection 32. Amalgam is obtained by adding 3.5% of mercury to a base metal made of an alloy of bismuth and indium, for example. The amalgam container 5 is provided with, for example, two holes (not shown) for allowing mercury vapor to enter and exit the amalgam. The discharge gas is composed of, for example, a rare gas such as argon and mercury vapor released from the amalgam. In the manufacturing process of the valve 3, the valve 3 is first shaped so that the tip (lower end) of the exhaust convex portion 32 is opened, and the exhaust through the exhaust convex portion 32 and the rare gas are sealed into the valve 3. After the amalgam container 5 and the support rod 6 made of, for example, glass for supporting the amalgam container 5 are introduced into the exhaust projection 32 later, the lower end of the exhaust projection 32 is closed by, for example, welding. That is, the vertical position of the amalgam container 5 in the exhaust convex portion 32 is adjusted by the vertical dimension (length) of the support bar 6.

  When high-frequency power is supplied to the induction coil 4, a discharge is generated in the bulb 3 by the generated high-frequency electromagnetic field, and mercury in the discharge space 30 is excited by the electrons generated by the discharge to emit ultraviolet light. A fluorescent material (not shown) is applied to the inner surface of the bulb 3, and ultraviolet light is converted into visible light by this fluorescent material and emitted outside the bulb 3.

  Further, a U-shaped support body 91 having one end inserted into the exhaust projection 32 and a flat flag 92 fixed to the other end of the support body 91 are provided in the valve 3. The flag 92 is coated with a metal compound such as cesium hydroxide having a relatively small work function, and this metal compound increases the number of electrons at the time of starting to improve startability.

Further, on the inner surface of the exhaust convex portion 32, a container stop convex portion 32 a that is located above the amalgam container 5 and prevents the amalgam container 5 from dropping from the exhaust convex portion 32 to the discharge space 30, and exhausted by the support 91. A flag-locking projection that prevents the support 91 from falling off the exhaust projection 32 by locking a locking projection 91a that protrudes in a direction approaching the flag 92 from one end on the side inserted into the projection 32. 32b protrudes to the inside of the exhaust projection 32.
Japanese Patent Laid-Open No. 2005-197031

  In this type of electrodeless discharge lamp device, the vapor pressure of mercury in the discharge space 30 depends on the saturated vapor pressure of mercury at the temperature at the location of the amalgam container 5. Therefore, for example, when dimming is performed when the ambient temperature is low, if the temperature at the position of the amalgam container 5 becomes too low, the vapor pressure of mercury in the bulb 3 may become too low. . Further, even when the saturated vapor pressure of mercury at the temperature at the position of the amalgam container 5 is sufficiently high, if the temperature of the amalgam is low, the diffusion of mercury from the inside of the amalgam to the surface is slowed down. The vapor pressure does not reach the saturation vapor pressure, and as a result, the vapor pressure of mercury may become too low. And if the vapor pressure of mercury in the discharge space 30 becomes too low, the light output of the electrodeless discharge lamp 1 will decrease.

  The present invention has been made in view of the above-mentioned reasons, and an object thereof is an electrodeless discharge lamp device capable of ensuring the vapor pressure of mercury in a bulb, and a lighting fixture using the electrodeless discharge lamp device. Is to provide.

  The invention of claim 1 is an electrodeless discharge lamp device comprising a bulb made of a light-transmitting material and filled with a rare gas and amalgam, and an induction coil, and the induction coil is housed on the outer surface of the bulb. The discharge space provided with the storage recess and filled with the rare gas in the bulb is continuously formed on the entire circumference of the storage recess viewed from the depth direction of the storage recess and the outer bottom surface side of the storage recess. A cylindrical coupler that is wound around the induction coil and inserted into the storage recess of the bulb, and has an exhaust projection that is inserted into the coupler with a cavity communicating with the discharge space inside the bottom of the storage recess. And the amalgam is arranged in the exhaust convex part on the side of the insertion direction of the coupler into the storage concave part rather than the induction coil.

  According to this invention, the vapor pressure of mercury in the bulb can be ensured by arranging the amalgam at a relatively high temperature position in the exhaust projection.

  According to a second aspect of the present invention, in the first aspect of the present invention, the valve has a spherical outer surface, and the amalgam is located in the exhaust convex portion where the outer diameter of the valve is maximum when viewed from the depth direction of the storage concave portion. Further, the coupler is arranged on the insertion direction side of the coupler into the storage recess.

  The invention of claim 3 is characterized in that, in the invention of claim 1 or 2, the amalgam is housed in the exhaust projection in a state of being housed in an amalgam container having an opening through which mercury vapor passes.

  According to this invention, compared with the case where an amalgam container is not used, it is easy to keep the position of the amalgam where the solid layer and the liquid layer are mixed in a relatively high temperature position in the exhaust projection.

  The invention of claim 4 is characterized in that, in the invention of claim 3, the amalgam container is made of ceramic.

  According to this invention, it is easy to ensure the temperature of an amalgam compared with the case where an amalgam container is comprised with the material whose heat conductivity is lower than a ceramic.

  According to a fifth aspect of the present invention, in the invention of any one of the first to fourth aspects, a phosphor that converts ultraviolet light generated in the bulb into visible light is applied to the inner surface of the bulb, The outer surface is provided only in a range closer to the opening of the housing recess than the induction coil.

  According to this invention, since no phosphor is provided around the amalgam container, the radiant heat from the plasma in the bulb is blocked by the phosphor as compared with the case where the phosphor is provided around the amalgam container. Without reaching the amalgam container, the temperature of the amalgam can be increased.

  A sixth aspect of the present invention is the heat insulating body according to any one of the first to fifth aspects, wherein the heat insulating body is made of a material having a lower thermal conductivity than the valve and is attached to the coupler and surrounds the amalgam when viewed from the depth direction of the housing recess. Is provided.

  According to the present invention, since the heat of the amalgam is difficult to escape by the heat insulator, the temperature of the amalgam is ensured even when the ambient temperature is lowered or when the power supplied to the induction coil is lowered compared to the case where the heat insulator is not provided. It becomes easy to do.

  A seventh aspect of the invention comprises the electrodeless discharge lamp device according to any one of the first to sixth aspects, a high-frequency power source that supplies high-frequency power to the induction coil, and an instrument body that houses the high-frequency power source. Lighting equipment to do.

  According to the present invention, the amalgam is disposed at a relatively higher temperature in the exhaust projection, which is closer to the insertion direction of the coupler into the housing recess than the induction coil. The vapor pressure can be secured.

  Further, according to the invention of claim 3, it is easy to keep the position of the amalgam by using the amalgam container.

  Furthermore, according to the invention of claim 4, the amalgam container is made of ceramic having high thermal conductivity, and according to the invention of claim 5, by not providing a phosphor around the amalgam container, According to the invention, by providing a heat insulator around the amalgam container, it is easy to keep the temperature of the amalgam container high.

  The best mode for carrying out the present invention will be described below with reference to the drawings.

  Since the basic configuration of this embodiment is the same as that of the conventional example, the corresponding parts are denoted by the same reference numerals, and detailed description of the common parts is omitted.

  In this embodiment, the amalgam container 5 which accommodated the amalgam is arrange | positioned above the induction coil 4, as shown in FIGS. FIG. 1 shows an instrument body 7 that contains a high-frequency power source that is electrically connected to an induction coil via an electric wire 7a and supplies high-frequency power to the induction coil 4, and FIGS. The range in which the phosphor 8 is provided is indicated by a broken line. Since the high-frequency power source and the phosphor 8 can be realized by well-known techniques, detailed description and illustration are omitted.

  Further, as the material of the amalgam container 5, a ceramic having a higher thermal conductivity than the metal used in the conventional example is used. Specific examples of materials that can be used include aluminum oxide, aluminum nitride, boron nitride, silicon carbide, silicon nitride, and beryllium oxide.

  Here, the present inventor examined the relationship between the temperatures of the four locations a to d in the exhaust projection 32 and the ambient temperature when the electrodeless discharge lamp device of FIG. 1 was turned on. The results are shown in FIG. As can be seen from FIG. 4, the point at which the highest temperature is stably maintained is the point a on the upper side of the induction coil 4 (that is, the insertion direction side of the coupler 2 into the housing recess 31). Therefore, in this embodiment, the amalgam container 5 is arranged at this point a. This point a is above the position where the diameter of the valve 3 is the largest when viewed from the depth direction of the storage recess 31 (the position of the broken line BL in FIG. 2).

  According to the above configuration, the vapor pressure of mercury in the bulb 3 is maintained even when the dimmer lighting is performed in a low temperature environment by setting the amalgam container 5 at a relatively high temperature in the bulb 3. Can be secured, and disappearance can be suppressed.

  Moreover, by using a ceramic having a higher thermal conductivity than metal as the material of the amalgam container 5, it is possible to keep the temperature of the amalgam even higher than when the amalgam container 5 is made of metal as in the conventional example. it can.

  As shown in FIG. 5, the phosphor 8 is not provided on the outer surface (surface on the discharge space side) of the storage recess 31 above the induction coil 4 (that is, in a range away from the opening of the storage recess 31). It may be. If this configuration is adopted, the phosphor 8 is not provided around the amalgam container 5, and the radiant heat from the plasma in the discharge space 30 reaches the amalgam more efficiently without being blocked by the phosphor 8. The temperature of the amalgam can be kept higher.

  Further, as shown in FIG. 6, the coupler 2 may be provided with a tubular heat insulator 23 made of a material having low thermal conductivity and surrounding the amalgam container 5 when viewed from the depth direction of the storage recess. If this configuration is adopted, the heat in the vicinity of the amalgam container 5 is difficult to escape, so that the temperature of the amalgam can be suppressed and the temperature of the amalgam can be ensured when dimming or when the ambient temperature is lowered.

It is sectional drawing which shows embodiment of this invention. It is sectional drawing which shows an electrodeless discharge lamp same as the above. It is sectional drawing which shows the principal part same as the above. It is explanatory drawing which shows the relationship between the temperature of the points ad of FIG. 1, and ambient temperature. It is sectional drawing which shows the principal part of another form same as the above. It is sectional drawing which shows the principal part of another form same as the above. It is sectional drawing which shows a prior art example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Electrodeless discharge lamp 2 Coupler 3 Valve 4 Inductive coil 5 Amalgam container 7 Instrument body 8 Phosphor 31 Storage recess 32 Exhaust protrusion

Claims (7)

An electrodeless discharge lamp device comprising a bulb made of a translucent material and containing a rare gas and an amalgam, and an induction coil,
A storage recess for storing the induction coil is provided on the outer surface of the valve,
The discharge space in which the rare gas is enclosed in the bulb is continuously formed on the entire circumference of the storage recess as viewed from the depth direction of the storage recess and the outer bottom surface side of the storage recess.
A cylindrical coupler that is wound around the induction coil and inserted into the storage recess of the valve,
On the bottom surface of the storage recess, an exhaust projection that has a cavity communicating with the discharge space inside and is inserted into the coupler protrudes to the inside of the storage recess.
The electrodeless discharge lamp device according to claim 1, wherein the amalgam is disposed in the direction of insertion of the coupler into the housing recess rather than the induction coil in the exhaust projection. The bulb has a spherical outer surface,
2. The amalgam is disposed in the exhaust projection portion on the insertion direction side of the coupler into the storage recess portion from a position where the outer diameter of the valve is maximized when viewed from the depth direction of the storage recess portion. The electrodeless discharge lamp device described.   3. The electrodeless discharge lamp device according to claim 1, wherein the amalgam is stored in the exhaust projection in a state of being stored in an amalgam container having an opening through which mercury vapor passes.   4. The electrodeless discharge lamp device according to claim 3, wherein the amalgam container is made of ceramic. A phosphor that converts ultraviolet light generated in the bulb into visible light is applied to the inner surface of the bulb,
The electrodeless discharge lamp device according to any one of claims 1 to 4, wherein the phosphor is not provided on the outer surface of the housing recess in a range farther from the opening of the housing recess than the induction coil.   6. The heat insulating body having a shape surrounding the amalgam as viewed from the depth direction of the housing recess, which is made of a material having a lower thermal conductivity than that of the bulb and is attached to the coupler. Electrodeless discharge lamp device. An illumination fixture comprising: the electrodeless discharge lamp device according to any one of claims 1 to 6; a high-frequency power source that supplies high-frequency power to the induction coil; and a fixture body that stores the high-frequency power source.

Images