JP2014026894A - Circular fluorescent lamp and lighting fixture using circular fluorescent lamp as light source - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a bright, highly efficient and compact circular fluorescent lamp, in which the coldest point temperature can be controlled easily even in the case of an enclosed type.SOLUTION: The circular fluorescent lamp includes two annular luminous tubes having different annular diameter, one discharge path formed by connecting one ends of the annular luminous tubes by bridge joint and providing electrodes at the ends of the other outer ring and inner ring, and a base surrounding a coldest point at the end of the bridge joint and the other end provided with the electrode. The base is provided with a heat transfer member for connection with the circular luminous tube end where the coldest point is located.

Description

  The present invention relates to an annular fluorescent lamp and a lighting fixture using the annular fluorescent lamp as a light source.

  A problem with fluorescent lamps is that when the temperature in the tube rises, the mercury vapor pressure inside increases, resulting in a decrease in the brightness and luminous efficiency of the fluorescent lamp. 2. Description of the Related Art Conventionally, a technique for preventing a temperature rise in a tube, in particular, a technology for lowering the heat at the coldest spot, which is the lowest temperature in the tube of a fluorescent lamp, has been proposed.

  In Patent Document 1, by providing an opening penetrating the inside and outside of the base of the annular fluorescent lamp, the coldest spot temperature is appropriately controlled and brightness even in a use state where the ambient temperature of the lamp rises. There has been proposed a ring-shaped fluorescent lamp which improves the above.

  In Patent Document 2, a cooling hole is provided in the base, and a partition that blocks the power feeding portion and the ventilation hole in the base is provided. An annular fluorescent lamp has been proposed in which the spot temperature is appropriately controlled to suppress a decrease in brightness and luminous efficiency.

Japanese Patent No. 2791304 Japanese Patent No. 3135526

  There are two types of lighting fixtures to which the annular fluorescent lamp is attached: a non-sealed type and a sealed type.

  In the non-sealed type, the space in which the annular fluorescent lamp is accommodated is not closed. That is, in the non-sealed type, the temperature around the annular fluorescent lamp is circulated to some extent with the temperature outside the lighting fixture. Therefore, when the annular fluorescent lamp described in Patent Documents 1 and 2 is attached to the non-sealed type lighting fixture, The coldest spot temperature can be appropriately controlled by the provided opening and ventilation hole.

  On the other hand, in the sealed type, the space for storing the fluorescent lamp is closed. That is, in the sealed type, the temperature around the annular fluorescent lamp is not circulated. Therefore, the lamp temperature in the lighting fixture is further increased by 15 to 25 ° C. than when only the lamp is turned on, and the temperature in the sealed lighting fixture is 50 to 60 ° C. Therefore, when the annular fluorescent lamp described in Patent Documents 1 and 2 is attached to an unsealed type, the ambient temperature of the annular fluorescent lamp itself rises, so that the coldest spot temperature exceeds 40 to 50 ° C. As a result, the brightness and luminous efficiency of the annular fluorescent lamp may be reduced.

  An object of the present invention is to provide a bright and highly efficient ring-shaped fluorescent lamp that can easily control the coldest spot temperature even in a sealed type, and a lighting apparatus that uses the ring-shaped fluorescent lamp as a light source.

  The fluorescent lamp of the present invention is composed of two annular arc tubes having different ring diameters, one end of the annular arc tube being connected by a bridge joint, and an electrode provided at the other outer ring and the end of the inner ring. An annular fluorescent lamp having a cold spot formed at one end of the bridge junction and a base surrounding the other end provided with the electrode. A heat conducting member connected to the end of the annular arc tube where the cold spot is located is provided.

  Even in a sealed type, the cold spot temperature can be easily controlled, and a bright and highly efficient ring-shaped fluorescent lamp and a lighting apparatus using the ring-shaped fluorescent lamp as a light source can be provided.

Front fragmentary view of an annular fluorescent lamp which is an embodiment of the present invention Enlarged view of a fragmentary part of a ring-shaped fluorescent lamp The figure which shows the ambient temperature characteristic of the annular fluorescent lamp which is this invention and the prior art Example

  Embodiments of the present invention will be described below with reference to the drawings.

  FIG. 1 is a front fragmentary view of an annular fluorescent lamp. In the annular fluorescent lamp 100, two annular arc tubes 1 and 2 having different ring diameters are provided on the same plane, and one end portion of the annular arc tubes 1 and 2 is connected by a bridge joint 3, and the other One discharge path is formed by the electrodes 4 and 5 provided at the end, and the base 6 surrounding the coldest point at the end of the bridge junction 3 and the other end provided with the electrodes 4 and 5. And the base 6 is provided with a heat conducting member 7 that connects the end of the annular arc tube where the coldest spot is located.

  In the annular fluorescent lamp according to the embodiment of the present invention shown in FIG. 1, an annular arc tube 1 serving as an outer ring and an annular arc tube 2 serving as an inner ring are disposed on the same plane, and are disposed substantially concentrically. Each of the annular arc tubes 1 and 2 is connected by a bridge junction 3 in the vicinity of one end portion, and a stem having electrodes 4 and 5 is sealed at the other end, and the electrode of the annular arc tube 1 of the outer ring is sealed. 4 and one discharge path to the electrode 5 of the inner ring-shaped arc tube 2 are formed. Phosphors are applied to the inner surfaces of the annular arc tubes 1 and 2, and 150 to 800 Pa of rare gas such as argon, neon, and krypton and mercury are sealed in the tubes. The cold spot of the annular fluorescent lamp of the present invention is located at the end where the bridge junction 3 of the annular arc tube 1 of the outer ring is in the vicinity, and the base 6 surrounds the respective ends of the annular arc tubes 1 and 2. is set up. The base 6 is provided with a heat conducting member 7 at a position corresponding to the end of the annular arc tube 1 of the outer ring that is the coldest point, and the cold conducting point 7 and the heat conducting member 7 installed on the base 6 are internally connected. Has been. Thereby, the heat radiation path for cooling the coldest spot is created, and the coldest spot temperature for determining the mercury vapor pressure is controlled to the optimum temperature range.

  FIG. 2 is a fragmentary enlarged view of a main part of an annular fluorescent lamp which is an embodiment of the present invention as in FIG.

An annular fluorescent lamp according to an embodiment of the present invention shown in FIG. 2 has a cold spot (not shown) at the end of an annular arc tube 1 serving as an outer ring and a base 6 installed so as to surround the end. The provided heat conducting member 7 is connected by a heat dissipating adhesive 8, and the heat conducting member 7 provided on the base 6 is connected to a metal lamp holder 9. A heat dissipation path is formed. The lamp holder 9 is provided in a lighting fixture such as a ceiling light. The heat dissipating adhesive 8 reliably creates a heat dissipating path for cooling the coldest spot without interrupting it and controls the coldest spot temperature for determining the mercury vapor pressure to the optimum temperature range. In particular, if the lamp holder 9 is attached to the heat radiating plate 10 exposed to the outside of the lighting fixture in the lighting fixture, the coldest spot in the annular fluorescent tube and the heat conducting member 7 are in contact with each other. The lamp holder 9 comes into contact, and the lamp holder 9 and the heat sink 10 come into contact. According to this, the outside of the lighting fixture and the coldest spot are connected by the heat dissipation path. It is possible to form a series of heat radiation paths for cooling the coldest spot by bringing the heat conductive member provided in the base into contact with the metal lamp holder provided in the lighting fixture by contacting the coldest spot with the heat dissipation path. Because the other end of the coldest point of the formed heat dissipation path is radiated outside the sealed lighting fixture, the brightness and luminous efficiency of the lamp are easily kept at the maximum value, and it is bright, highly efficient and compact ring-shaped fluorescence A lamp can be realized. In addition, it is desirable that the heat conductive member provided in the base has an area of 25 to 150 mm ² that covers the coldest spot of the fluorescent lamp while avoiding a short circuit with the power feeding portion to the electrode.

  FIG. 3 shows a graph comparing the thus formed annular fluorescent lamp of the present invention and a conventional annular fluorescent lamp. The annular fluorescent lamp in the present invention is formed under the following conditions. The outer diameter of the annular arc tubes 1 and 2 is 20 mm, the outer diameter of the annular arc tube 1 serving as the outer ring is 400 mm, the inner diameter of the annular arc tube 2 serving as the inner ring is 314 mm, and the electrode side ends of the annular arc tubes 1 and 2 The distance between the opening and the non-electrode side end is 21 mm, and the base is 20 mm long x 3 mm wide x 1 mm thick, made of copper, the light source color is daylight color (light source color symbol ED), rated lamp Formed a 97W ring fluorescent lamp. The total luminous flux of the product of the present invention in which the heat conducting member is provided in the base and the total luminous flux of the conventional product in which the thermal conducting member is not provided in the base are shown as relative values with the total luminous flux at the ambient temperature of 25 ° C. being 100%. 3 shows. In this case, the temperature in the sealing fixture of the ceiling light is about 52 ° C. in either case.

  As a result of lighting each of the annular fluorescent lamps in a sealing light sealing device, the product of the present invention in which a heat conducting member is provided on the base has a coldest point temperature determining mercury vapor pressure lower by about 5 ° C. than the conventional product, The brightness of the ceiling light is improved by about 9%, approaching the optimal cold spot temperature range of 40-50 ° C., and the brightness and luminous efficiency of the lamp are improved.

  As described above, the present invention connects the end of the annular fluorescent lamp on the non-electrode side where the coldest point is located and the heat conduction member provided on the base, so that it can be used for lighting a sealing device such as a ceiling light. A reduction in brightness can be suppressed, and a bright and highly efficient lamp can be obtained.

DESCRIPTION OF SYMBOLS 1, 2 ... Ring-shaped arc tube 3 ... Bridge junction part 4, 5 ... Electrode 6 ... Base 7 ... Thermal conduction member 8 ... Heat radiation adhesive 9 ... Lamp holder

Claims (3)

  Two annular arc tubes having different ring diameters, one end of the annular arc tube is connected by a bridge joint, and one discharge path is formed by electrodes provided at the other outer ring and the end of the inner ring, An annular fluorescent lamp having a cold spot at the end of the bridge joint and a base surrounding the other end provided with the electrode, wherein the cold spot is located in the base. An annular fluorescent lamp comprising a heat conducting member connected to an end of an arc tube.   2. The annular fluorescent lamp according to claim 1, wherein a heat dissipating adhesive is provided to connect a heat conducting member provided in the base and an end of the annular arc tube where the coldest point is located. Annular fluorescent lamp.   3. A lighting apparatus using the annular fluorescent lamp as a light source according to claim 1 or 2, wherein a heat conductive member provided in the base and a lamp holder made of a metal material for holding the lamp are connected to form a heat dissipation path. Characteristic lighting equipment.