The present invention relates to a technology to fit a bulb to a coupler member in an electrodeless discharge lamp.
A conventional electrodeless discharge lamp has no electrode formed inside a light emitting tube, so that in contrast to a general discharge lamp such as a fluorescent lamp, it is free from a lighting failure due to electrode break. Thus, it has the advantage of longer life than a general fluorescent lamp or the like.
As shown in Published Japanese Translation of PCT Application Hei 11-508404, for example, an example of such a known electrodeless discharge lamp fills a discharge gas in a bulb, and applies a high frequency electromagnetic field thereto so as to excite the discharge gas in the bulb for emitting light.
This electrodeless discharge lamp comprises a lamp part as a light emitting body and a coupler member fitted to the lamp part. The lamp part has a bulb containing a discharge gas, and a base which fixes and supports the bulb and which is fitted to the coupler member. The coupler member, which forms an induction coil, has a coil and a heat conductive body for generating electromagnetic energy as well as an attachment member to be fitted to the base. The base and the attachment member of the coupler member are respectively formed of synthetic resin, enabling the lamp part to be attached to and detached from the coupler member, and preventing the lamp part from being easily detached from the coupler member in a state where both are attached to each other.
In this electrodeless discharge lamp, the base and the attachment member of the coupler member are respectively formed of synthetic resin, so that there is a risk that the electrodeless discharge lamp, if used for a long time, may decrease in strength due to degradation of the synthetic resin. Thus, it is considered that it becomes unable to securely fit the lamp part to the base and fit the coupler member to the base in the electrodeless discharge lamp.
An object of the present invention, to solve the problems of the prior art described above, is to provide an electrodeless discharge lamp which prevents the problem of decrease in strength due to degradation of resin material, allowing secure fitting of the lamp part to the base and of the coupler member to the base in the electrodeless discharge lamp, even if the electrodeless discharge lamp is used for a long time.
According to the present invention, the above-described object is achieved by an electrodeless discharge lamp comprising: a bulb having a discharge container containing a discharge gas inside thereof; a base for fixing and supporting the bulb; and a coupler member detachably fitted via the base to, and for exciting, the bulb, wherein the base comprises a metal frame for fixing the discharge container of the bulb, and a resin cover for covering the metal frame.
According to such structure, the base comprises the metal frame and the resin cover for covering the metal frame, in which the metal frame fixes the discharge container of the bulb. Thus, it undergoes less material degradation than a conventional one which uses a base of resin material, making it possible to securely fix the bulb to the base for a long time. Further, the resin cover has a function of a bulb attaching guide, so that it is possible to protect the gas outlet tube of the bulb when attaching the bulb to the coupler member
An embodiment embodying the present invention will be described with reference to the drawings.
As shown in
As shown in
When high frequency power is supplied to the tube lamp cable 41 of the coupler member 4, the induction coil 44 generates a high frequency magnetic field. Thus, the discharge gas filled in the inside 21b of the bulb outer tube 21 is excited by the energy of the high frequency magnetic field it receives, to discharge and emit ultraviolet light. The emitted ultraviolet light is converted to visible light by the fluorescent material coated on the inner surface 21c of the bulb outer tube 21.
Next, referring to
Furthermore, the base cover 31 has formed at an upper portion thereof bulb fixing post covers 311 (post portions of the resin cover) for covering the bulb post portions of the base frame 32. The bulb fixing post covers 311 each have formed therein a stopper mounting hole 312 (hole) passing therethrough into which a later-described stopper for fixing the bulb 2 by being fitted into the bulb groove 23 of the bulb 2 is to be inserted and fitted.
A plurality, here three, of coupler member fixing projections 321 and coupler member fixing grooves 322 to be fitted to the base fitting portions 42 of the coupler member 4 are formed on a periphery of a lower portion of the base frame 32, equidistantly on the circumference. Further, an opening portion 324 is formed at about its center. The coupler member attaching guide 313 of the base cover 31 is fitted into the opening portion 324, while an end of the gas outlet tube 22 is positioned at about the center of the coupler member attaching guide. Further, a plurality of screw holes 323 for inserting screws (not shown) to connect the base frame 32 and the base cover 31 are similarly equidistantly formed around the opening portion 324.
Next, referring to
The bulb fixing posts 325 of the base frame 32 each have provided at an end thereof a stopper mounting hole 326 (hole) into which a later-described stopper is to be inserted and fitted to fix the bulb 2. U-shaped coupler member fixing projections 321 and coupler member fixing grooves 322 are provided on a periphery of a lower portion of the base frame 32, and are respectively fitted to the base fitting portions 42 of the coupler member 4.
A plurality, here three, of bulb fixing post covers 311 are equidistantly formed on a peripheral side surface of the base cover 31. The bulb fixing post covers 311 each have formed therein a stopper mounting hole 312 (hole) through which a later-described stopper passes. Provided inside the base cover 31 are: a coupler member attaching guide 313 having a through-hole 317 for attaching the coupler member 4 in axial direction of the bulb 2; and a bulb attaching guide 315 also having a through-hole 318 and having a guide function to protect the gas outlet tube 22 when attaching the bulb 2 to the coupler member 4. Further, screw holes 314 into which screws for connection to the base frame are to be inserted and fitted are formed around the coupler member attaching guide 313. In a state in which the base frame 32 is covered by the base cover 31, the screw holes 314 provided in the base cover 31 are placed just above the screw holes 323 provided in the base frame 32, while the bulb fixing post covers 311 cover the bulb fixing posts 325. The stopper mounting holes 326 formed in the base frame 32 and the stopper mounting holes 312 formed in the base cover 31 are positioned in direction facing the bulb groove 23 and perpendicular to the axial direction of the bulb 2.
Next, referring to
Referring to
Next, the coupler member 4 is fitted to the base 3 in the state shown in
Next, referring to
Next, the state in which the stoppers 5 and the stopper covers 6 described above are attached to the electrodeless discharge lamp 1 will be described with reference to
After the fitting of the stopper 5, the stopper cover 6 is fitted into the stopper mounting hole 312a of the base cover 31. Here, the semicircular shaped projecting portion 62 of the stopper cover 6 is hooked by an end of the stopper mounting hole 312a and an end of the stopper mounting hole 326 of the bulb fixing post 325 by using elasticity, while the projecting portion 61 moves along an inner surface of the base cover 31, and the projecting portion 63 at the upper portion is attached to a recessed portion formed on the inner surface of the base cover 31. Here, the rib portion 64 of the stopper cover 6 is press-contacted with the L-shaped portion 53 and the large width portion 54 of the stopper 5. The stopper mounting hole 312 of the base cover 31 is thereby covered. This prevents e.g. workers from directly contacting the metal stoppers 5. Thus, e.g. the workers can handle the electrodeless discharge lamp 1 safely.
Next, test results of the electrodeless discharge lamp according to the present embodiment will be described. An electrodeless discharge lamp 1 was prepared by attaching a base 3 and a coupler member 4 to a bulb 2 with a sphere diameter of the bulb outer tube of 180 F (sic: 180 mm diameter), a weight of the bulb outer tube of 380 g and a height of the bulb outer tube of 260 mm, and was subjected to vibrations with an acceleration of 10 G As a result, this electrodeless discharge lamp 1 normally emitted light without breaking with the respective elements being securely fitted to each other. Further, it was found from experimental results that the present invention is effective for those which have a weight of the bulb outer tube 21 of over 200 g or have a high-moment joint portion between the bulb 2 and the base 3.
It is to be noted that the electrodeless discharge lamp according to the present invention is not limited to the structure as shown in the embodiment described above, and various modifications are possible as desired within the scope which does not change the spirit the present invention. For example, the base cover 31 and the stopper cover 6 can be formed of white resin so as to increase light reflectance, thereby increasing light extraction efficiency of the electrodeless discharge lamp 1.
In addition, the embodiment described above has shown one in which three of the bulb fixing posts 325, bulb fixing post covers 311 and stopper mounting holes 312, 326 are formed on the circumference, respectively, but it is not limited thereto, and an appropriate number can be used.
This application is based on Japanese patent application 2005-246854, the content of which is to be consequently incorporated into the present invention by reference to the specification and drawings of the above-described patent application.
The present invention has been sufficiently described using presently preferred embodiments with reference to the attached drawings, but it may be obvious to those ordinarily skilled in the art that various alterations and modifications are possible. Accordingly, such alterations and modifications do not depart from the scope of the present invention, and should be interpreted to be included within the scope of the present invention.
Number | Date | Country | Kind |
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2005-246854 | Aug 2005 | JP | national |
Filing Document | Filing Date | Country | Kind | 371c Date |
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PCT/JP2005/017880 | 9/28/2005 | WO | 00 | 2/25/2008 |
Publishing Document | Publishing Date | Country | Kind |
---|---|---|---|
WO2007/023572 | 3/1/2007 | WO | A |
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Number | Date | Country | |
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20100066233 A1 | Mar 2010 | US |