JP2008117669A - Electrodeless discharge lamp; and electrodeless discharge lamp device and luminaire using it - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electrodeless discharge lamp capable of preventing damage of a projecting part by contact; and a luminaire using it. <P>SOLUTION: This electrodeless discharge lamp comprises a nearly-U-shaped long tube body 10 formed of a translucent material, and a nearly-U-shaped short tube body 11 having a total length smaller than that of the long tube body 10; is composed by filling a discharge gas (argon) containing mercury in a nearly-oval bulb 1 formed by connecting both ends of the respective tube bodies 10 and 11 to each other to form a tube wall of a closed loop having a tube axis of a closed loop; and is provided with a projecting part 12 becoming the coldest point to project from the inside tube wall of a bent part 11 of the short tube body 11 toward a space surrounded by the bulb 1. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

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

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. This electrodeless discharge lamp is a tube made of a translucent material, and both ends of the tube are connected so as to form a closed-loop tube wall having a closed-loop tube axis, and a discharge gas containing mercury is enclosed. An ellipse-shaped bulb, an induction coil that is disposed close to the bulb and is supplied with high-frequency power to generate a high-frequency electromagnetic field to excite the discharge gas, and surrounds the outer periphery of the glass tube and is an induction coil And a pair of cores wound around, and a high frequency power source is connected to the induction coil and a high frequency current is supplied to the induction coil to emit light. On the tube wall outside the valve, a protrusion protruding toward the outside of the valve is provided integrally with the valve, and the protrusion is the coldest part inside the valve, that is, the coldest point, The mercury vapor pressure in the bulb is controlled to an appropriate value to prevent a decrease in luminous efficiency.
JP-A-10-116591

  However, in the above conventional example, since the protruding portion is formed to protrude outside the valve, the protruding portion is damaged by contact with the protruding portion during construction such as transportation or attachment to a device, resulting in an airtight state of the valve. As a result, the atmospheric gas may enter the bulb and cannot be discharged. Therefore, it is conceivable to increase the mechanical strength by shortening the protrusion length of the protrusion and increasing the diameter of the cross section. However, if the diameter of the cross section is increased, the plasma can easily enter the protrusion, and the plasma There is a concern that the temperature of the protrusion, which is the coldest point, rises and the luminous efficiency decreases.

  The present invention has been made in view of the above points, and an object of the present invention is to provide an electrodeless discharge lamp capable of preventing damage to a protrusion due to contact and a lighting fixture using the same.

  In order to achieve the above object, the invention of claim 1 is a tube made of a light-transmitting material, and both ends of the tube are connected so as to form a closed-loop tube wall having a closed-loop tube axis. The electrodeless discharge lamp has a bulb in which a discharge gas containing mercury is sealed, and generates high-frequency electromagnetic fields by supplying high-frequency power to an induction coil disposed close to the bulb to excite the discharge gas. Thus, a protrusion is provided that protrudes from a tube wall inside the bulb toward a space surrounded by the bulb.

  The invention of claim 2 is characterized in that, in the invention of claim 1, at least one core surrounding the outer periphery of the valve and around which the induction coil is wound is arranged in the vicinity of the protrusion.

  According to a third aspect of the present invention, the electrodeless discharge lamp according to the first or second aspect, the induction coil, and a high-frequency power source for supplying a high-frequency current to the induction coil are provided.

  According to a fourth aspect of the invention, there is provided an electrodeless discharge lamp device according to the third aspect of the present invention, and an appliance main body that houses the electrodeless discharge lamp device.

  According to the first aspect of the present invention, since the protruding portion that protrudes from the inner tube wall of the bulb toward the space surrounded by the bulb is provided, the protruding portion can be the coldest point, and the protruding portion can be Since it is not exposed to the outside of the bulb, it does not come into contact during construction such as transportation or attachment to an instrument, and therefore it is possible to prevent the projection from being damaged by contact.

  According to the invention of claim 2, since the core is disposed in the vicinity of the protrusion, the temperature of the protrusion can be raised by the heat radiated from the core, and therefore the temperature of the protrusion is lowered when the ambient temperature is low. It is possible to prevent the light emission efficiency from being lowered.

  According to invention of Claim 3, the electrodeless discharge lamp apparatus which has the effect of Claim 1 or 2 can be provided.

  According to invention of Claim 4, the lighting fixture which has the effect of Claim 3 can be provided.

  Hereinafter, embodiments 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. 1, a substantially U-shaped long tube body 10 made of a translucent material and a substantially U-shaped short tube made of a translucent material and having a total length shorter than that of the long tube body 10. Mercury (not shown) is formed in a substantially oval-shaped bulb 1 which is composed of a tube body 11 and is connected to each other so as to form a closed-loop tube wall having both ends of each tube body 10 and 11 having a closed-loop tube axis. ) Including a discharge gas (argon) is provided, and a projecting portion 12 protruding from a tube wall inside the bulb 1 toward a space surrounded by the bulb 1 is provided.

  The protrusion 12 is provided so as to protrude from the inner wall of the bent portion 11a of the short tube 11 toward the space surrounded by the bulb 1, and the protrusion 12 is the coldest point. To control the mercury vapor pressure inside the valve 1 to an appropriate value. Further, a tip-off portion 13 is provided on the tube wall outside the bent portion 11a of the short tube body 11, from which mercury and a discharge gas are introduced into the bulb 1, and heated and melted by a burner. Then, mercury and discharge gas are sealed in the bulb 1 by chip-off.

  Hereinafter, the process of forming the long tube body 10 will be described with reference to the drawings. First, as shown in FIG. 2 (a), after the gas burner 4 is heated near the center in the longitudinal direction of a substantially cylindrical tube made of a light-transmitting material and reaches a temperature sufficient to bend. Bend into a U shape. At the time of bending, as shown in FIG. 2 (b), the bent portion 10a is crushed so that the diameter of the bent portion 10a becomes smaller than the diameter of other portions. The long tubular body 10 is formed by inflating the bent portion 10a by enclosing and pressurizing the inside of the body, adjusting the diameter of the bent portion 10a to a desired diameter, and then naturally cooling (FIG. 2 (c)). The short tube body 11 is also formed by the same process as described above. However, in the case of the short tube body 11, it is necessary to provide the protrusion 12 after the bent portion 11 a is heated by the gas burner 4 and before the bent portion 11 is bent. is there.

  In this embodiment, the total length of the long tube body 10 is about 430 mm, the total length of the short tube body 11 is about 70 mm, the total length of the valve 1 in a state where the long tube body 10 and the short tube body 11 are connected is about 500 mm, and the diameter is It is designed to be about 40 mm. Further, the protrusion 12 is designed to have a total length of about 10 mm and a diameter of about 8 mm. The short pipe body 11 may be formed by processing using a mold instead of the above bending process. In this case, there is an advantage that the protrusion 12 can be easily processed.

  As described above, the protrusion 12 is provided so as to protrude from the inner wall of the bent portion 11 a of the short tube 11 toward the space surrounded by the bulb 1. Therefore, it is possible to prevent the projecting portion 12 from being damaged by the contact.

  Hereinafter, embodiments of an electrodeless discharge lamp device according to the present invention will be described with reference to the drawings. As shown in FIG. 3, the present embodiment is connected to the above-described valve 1, a pair of cores 3 surrounding the outer periphery of the valve 1 and wound with an induction coil (not shown), and the induction coil. It comprises a high frequency power supply (not shown) for supplying a high frequency current to the induction coil. In the present embodiment, a high-frequency electromagnetic field generated by supplying a high-frequency current from a high-frequency power source to an induction coil is caused to act on the discharge gas inside the bulb 1 to discharge, and mercury is excited by discharge to emit ultraviolet rays. Light is emitted by converting ultraviolet light into visible light by a fluorescent material (not shown) applied to the inner surface of the bulb 1 and taking it out of the bulb 1.

The core 3 is a so-called toroidal type ferrite core having an outer diameter of about 80 mm and a cross-sectional area of about 12 cm ² , and an induction coil is wound around a part of the core 3. The core 3 is disposed so as to surround the connecting portions of the long tube body 10 and the short tube body 11, that is, in the vicinity of the protrusion 12. By arranging the core 3 in this way, the protrusion 12 is surrounded by the core 3 and the valve 1.

  In general, the electrodeless discharge lamp apparatus is designed at the coldest point so that the luminous efficiency is maximized when the ambient temperature is 25 ° C. However, when the ambient temperature falls below 25 ° C., the coldest is the coldest. Since the temperature at the point is also lowered, the mercury vapor pressure inside the bulb 1 is lowered and the luminous efficiency is lowered. Therefore, when the core 3 is disposed in the vicinity of the protrusion 12 that is the coldest point as in the present embodiment, in the state where the ambient temperature is lower than 25 ° C., the evaporation amount of mercury decreases, Although the energy loss increases and the light emission efficiency decreases, the temperature of the core 3 increases as the energy loss of the core 3 increases, and the protrusion 12 is surrounded by the core 3 and the bulb 1. The temperature of the projecting portion 12 is increased by the radiant heat. Therefore, a decrease in the temperature of the projecting portion 12 can be prevented, and a decrease in luminous efficiency can also be prevented. Further, in a state where the ambient temperature is higher than 25 ° C., the amount of mercury evaporation increases, energy loss in the core 3 decreases, and the core 3 does not reach a high temperature. Therefore, the protrusion 12 does not become unnecessarily high.

  As a specific example, when the protrusion 12 is provided so as to protrude outward from the outer tube wall of the valve 1 as in the conventional example, the protrusion 12 is formed on the bent portion 11a of the short tube body 11 as described above. FIG. 4 shows the result of measuring the luminous efficiency according to the ambient temperature when it is provided so as to protrude from the inner tube wall toward the space surrounded by the bulb 1. In any case, the core 3 is disposed so as to surround the connecting portions of the long tube body 10 and the short tube body 11 as described above. The measurement is performed at three points of ambient temperatures of −20 ° C., 25 ° C., and 60 ° C., and the luminous efficiency is 1 when the ambient temperature is 25 ° C.

  According to the figure, when the ambient temperature is low (−20 ° C.), the protrusion 12 protrudes from the inner wall of the bent portion 11 a of the short tube 11 toward the space surrounded by the bulb 1. The luminous efficiency when the protrusion 12 is provided so as to protrude outward from the tube wall outside the bulb 1 (shown by the solid line in FIG. And the effect obtained by arranging the core 3 in the vicinity of the protrusion 12 appears. When the ambient temperature is high (60 ° C.), the protrusion 12 is provided so as to protrude from the inner wall of the bent portion 11 a of the short tube 11 toward the space surrounded by the bulb 1. The luminous efficiency is slightly lower than when the protrusion 12 is provided so as to protrude outward from the tube wall outside the bulb 1, but is hardly affected by the radiant heat from the core 3.

  As described above, by disposing the core 3 in the vicinity of the protrusion 12, the temperature of the protrusion 12 can be increased by radiant heat from the core 3, and thus the temperature of the protrusion 12 is low when the ambient temperature is low. It is possible to prevent a decrease in luminous efficiency due to the decrease.

  A plurality of protrusions 12 may be provided. For example, as shown in FIG. 5, two protrusions 12 are provided on the tube wall inside the bent part 11 a of the short tube 11, A pair of cores 3 may be arranged in the vicinity. Further, the shape of the bulb 1 is not necessarily limited to the elliptical shape as described above. For example, as shown in FIG. 6, the long tubular body 10 and the short tubular body 11 that are bent into a substantially U-shape, respectively. You may form the substantially rectangular valve | bulb 1 which connected each both ends mutually. Further, the shape of the core 3 is not necessarily limited to the substantially annular shape as described above. For example, the core 3 may be formed in a substantially rectangular shape having an open central portion.

  In the electrodeless discharge lamp described above, it is also possible to form an electrodeless ultraviolet lamp by forming the bulb 1 from a material having good ultraviolet transmittance and not applying a fluorescent material to the inner surface of the bulb 1. It goes without saying that a lighting fixture can be constituted by the electrodeless discharge lamp device described above and a fixture main body (not shown) that houses the electrodeless discharge lamp device.

It is the schematic which shows embodiment of the electrodeless discharge lamp which concerns on this invention. It is a figure which shows the process of forming a long tubular body same as the above, (a) is the schematic which shows before bending, (b) is the schematic which shows before air enclosure, (c) is the outline which shows after air enclosure. FIG. It is the schematic which shows embodiment of the electrodeless discharge lamp apparatus which concerns on this invention. It is a graph which shows the correlation of luminous efficiency same as the above, and ambient temperature. It is the schematic which shows the case where multiple protrusion parts same as the above are provided. It is the schematic which shows the case where the shape of a long tube body and a short tube body same as the above is changed.

Explanation of symbols

1 Valve 10 Long tube 11 Short tube 12 Projection

Claims (4)

  A tube made of a translucent material, having a bulb in which both ends of the tube are connected and a discharge gas containing mercury is enclosed so as to form a closed-loop tube wall having a closed-loop tube axis; An electrodeless discharge lamp that excites the discharge gas by generating a high-frequency electromagnetic field by supplying high-frequency power to an induction coil disposed in the vicinity of the bulb, the space surrounded by the bulb from the tube wall inside the bulb An electrodeless discharge lamp comprising a protrusion protruding toward the surface.   2. The electrodeless discharge lamp according to claim 1, wherein at least one core surrounding the outer periphery of the bulb and around which an induction coil is wound is disposed in the vicinity of the protrusion.   3. An electrodeless discharge lamp device comprising: the electrodeless discharge lamp according to claim 1; the induction coil; and a high-frequency power source that supplies a high-frequency current to the induction coil. A lighting fixture comprising: the electrodeless discharge lamp device according to claim 3; and a fixture main body for housing the electrodeless discharge lamp device.

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