JP2008053186A - Electrodeless discharge lamp and lighting fixture - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electrodeless discharge lamp of low starting voltage and a lighting fixture using the electrodeless discharge lamp. <P>SOLUTION: The lamp includes a circular bulb 1 made of a translucent material with discharge gas sealed, and two pieces of coils 2 made of a material with magnetism made by winding wires 22 in a poloidal direction around a core 21 surrounding the bulb 1 in a poloidal direction. Each coil 2 has densely wound parts 22a at a plurality of sites where the wires 22 are more densely wound than at the other sites set in equal intervals in a toroidal direction. Thus, the starting voltage is lowered as compared with the case in which wires 22 are equally wound around the core 21 or a densely wound part 22a is provided only at one site. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

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

  Conventionally, for example, a bulb made of a light-transmitting material such as glass and having a ring shape in which both ends of the tube are connected to each other and sealed with a discharge gas, and a bulb made of a magnetic material are enclosed in the poloidal direction. There has been provided an electrodeless discharge lamp including a coil in which a winding is wound around a ring-shaped core in a poloidal direction (see, for example, Patent Document 1). The discharge gas is composed of, for example, a rare gas such as argon gas and mercury vapor.

That is, when a high frequency current is supplied to the winding of the coil, a discharge is generated in the bulb by a high frequency electromagnetic field generated by the coil, and the mercury in the discharge gas is excited by this discharge to emit ultraviolet light. A fluorescent material is applied to the inner surface of the bulb, and the ultraviolet light is converted into visible light by the fluorescent material, whereby the electrodeless discharge lamp emits light.
JP 2003-141990 A

  In this type of electrodeless discharge lamp, the higher the starting voltage, the larger the core needs to be in order to avoid magnetic saturation of the core. However, in the electrodeless discharge lamp, since the core is disposed outside the bulb and the core is generally opaque, the use efficiency of light decreases as the core increases. Therefore, it is desirable for this type of electrodeless discharge lamp to have a low starting voltage.

  The present invention has been made in view of the above-described reasons, and an object thereof is to provide an electrodeless discharge lamp having a low starting voltage and a lighting fixture using the electrodeless discharge lamp.

  According to the first aspect of the present invention, a bulb made of a light-transmitting material and having a ring shape and enclosing a discharge gas and a ring-shaped core made of a magnetic material and surrounding the bulb in the poloidal direction are wound in the poloidal direction. At least one coil formed by winding a wire, and each coil is provided with a plurality of densely wound portions with windings wound more densely than other parts at equal intervals in the toroidal direction. It is characterized by being.

  The invention of claim 2 is characterized in that, in the invention of claim 1, the closely wound portions are connected in parallel to each other.

  According to a third aspect of the present invention, in the first aspect of the present invention, the winding has a connecting portion for connecting the closely wound portions in series with each other, and the connecting portion has at least one lower density than the densely wound portion in the core. It is characterized by being wound.

  The invention of claim 4 is characterized in that, in the invention of claim 1, two coils are provided, and a connection line extending along the valve and electrically connecting the windings of different coils is provided.

  According to a fifth aspect of the present invention, in the fourth aspect of the invention, a noise removal line is provided that extends along the valve on the same side as the connection line with respect to the coil and flows in a direction opposite to the current flowing through the connection line. Features.

  Invention of Claim 6 is the electrodeless discharge lamp of any one of Claims 1-5, the high frequency power source which supplies high frequency power to the coil of this electrodeless discharge lamp, and the instrument main body which stores a high frequency power supply It is characterized by providing.

  In the present invention, each coil is provided with a plurality of densely wound portions in which the windings are wound more densely than other parts at equal intervals in the toroidal direction, and the windings are evenly distributed on the core. Experimental results have been obtained in which the starting voltage is reduced as compared with the case where the winding is wound or the case where only one densely wound portion is provided. Therefore, it is possible to reduce the size of the core while avoiding magnetic saturation of the core.

  According to the second aspect of the present invention, since the tightly wound portions are connected in parallel to each other, the inductance of the coil as a whole is lowered. Therefore, the design of the circuit of the high frequency power supply for supplying high frequency power to the coil Becomes easy.

  Furthermore, according to the invention of claim 3, since the connecting portion for connecting the closely wound portions in series in the winding is wound around the core at a lower density than the densely wound portion, the connecting portion is Compared with the case where the coil is not wound around the core, since the connecting portion is firmly held by the core, the winding of the winding around the core becomes easy at the time of manufacturing.

  According to the fourth aspect of the present invention, since the connecting wire extending along the valve and electrically connecting the windings of different coils is provided, the plasma is stretched at the start by the effect of the connecting wire. Improves.

  Furthermore, according to the invention of claim 5, the noise removal line is provided with a current that extends along the valve on the same side as the connection line with respect to the coil and flows in a direction opposite to the current flowing through the connection line. Because the electromagnetic field generated by cancels out the electromagnetic field generated by the connection line, electromagnetic noise radiated to the outside is reduced.

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

  In the present embodiment, as shown in FIG. 2, for example, the ends of two cylindrical straight pipe portions 11 made of a light-transmitting material such as glass are respectively connected via U-shaped connecting portions 12. A winding 22 is wound in a poloidal direction around a valve 1 in which a discharge gas is sealed with an elongated ring shape connected to each other, and a ring-shaped core 21 made of a magnetic material and surrounding the tube of the bulb 1 in the poloidal direction. And an instrument body 3 in which a printed wiring board (not shown) on which a high-frequency power circuit for supplying high-frequency power to the windings 22 of the coil 2 is mounted is housed. Since the high-frequency power supply circuit and the instrument body 3 can be realized by a well-known technique, illustration and detailed description are omitted. Hereinafter, the upper, lower, left and right will be described based on FIG. That is, the axial direction of the straight pipe portion 11 is referred to as the left-right direction, and the direction in which the straight pipe portions 11 are arranged is referred to as the up-down direction.

  The valve 1 has an exhaust pipe 13 protruding rightward from the right connecting portion 12. This is because the tip (right end) of the tube used for exhaust in the bulb 1 and introduction of discharge gas in the course of manufacturing the bulb 1 is closed at the final stage of production.

  One coil 2 is attached to each straight pipe portion 11 so as to be lined up and down at the right end portion.

  As shown in FIG. 1, the core 21 is formed by, for example, connecting two halves 21 a each having a semicircular arc shape so that the tube of the valve 1 is sandwiched from both sides in the vertical direction (the horizontal direction in FIG. 1). As a whole, it is of an annular shape.

  In addition, the windings 22 of the coils 2 are each a closely wound portion 22a that is densely wound a plurality of times (four times in the drawing) on both sides sandwiching the straight pipe portion 11 from the vertical direction (left-right direction in FIG. 1). And a connecting portion 22b for connecting the closely wound portions 22a. That is, the closely wound portions 22a are arranged at equal intervals of about 180 degrees, and in each coil 2, the closely wound portions 22a are connected to each other in series via the connecting portion 22b. In addition, the coils 2 are connected in series to each other via a connection line 4 arranged along the inner circumference on the shorter side of the portion on the right side of the coils 2 in the valve 1, that is, the portion sandwiched between the coils 2. ing. According to this configuration, the effect of the electromagnetic field generated by the connection line 4 and the connection line 4 which is a conductor extended in the toroidal direction of the valve 1 are compared with the case where the connection line 4 is arranged away from the valve 1. Due to the effect of being arranged close to the bulb 1, the plasma is stretched in the toroidal direction of the bulb 1 at the time of startup, so that the diffusion of the plasma is accelerated, so that the startability is improved.

  Here, instead of connecting the coils 2 in series as described above, the coils 2 may be connected in parallel as shown in FIG. The inventor of the present invention uses the configuration of FIG. 3 and two comparative examples in which only the winding method of the winding 22 is different from that of the present embodiment and the other portions are common to the present embodiment. It was measured. Specifically, in the comparative example, the winding 22 is provided evenly on the entire core 21 as shown in FIG. 4B and the case where only one densely wound portion 22a is provided as shown in FIG. It is a wound one. As a result, the starting voltage is 1.1 kV in the example of FIG. 4A and 0.9 kV in the example of FIG. 4B, whereas it is the lowest, 0.8 kV in this embodiment. It was. This is because the loss due to non-uniform magnetic flux is reduced by dispersing the winding 22 compared to the example of FIG. 4A, and the winding 22 is shortened compared to the example of FIG. 4B. This is considered to be an effect due to the fact that the loss is reduced.

  According to the above configuration, since the core 22 can be reduced in size while avoiding magnetic saturation by lowering the starting voltage, the entire lighting fixture can be reduced in size and weight, the light use efficiency can be improved, Manufacturing cost can be reduced.

  In the above embodiment, the densely wound portions 22a are provided at two locations. However, for example, as shown in FIG. 5, three or more densely wound portions 22a may be provided.

  Further, as shown in FIG. 6, in the winding 22, the connecting portion 22 b that connects the closely wound portions 22 a may be wound around the core 21 once, for example. If this configuration is adopted, the connecting portion 22b is firmly held with respect to the core 21 in the winding 22, so that winding of the winding 22 around the core 21 becomes easier at the time of manufacture, thereby improving the manufacturability. improves.

  Further, as shown in FIG. 7, if the connecting wire 4 is arranged along the inner circumference on the longer side of the portion of the bulb 1 on the left side of each coil 2, that is, the portion sandwiched between the coils 2, The startability is further improved than the case. In addition, a noise removal line that cancels an electromagnetic field generated by the connection line 4 due to a current flowing in a direction opposite to that of the connection line 4 may be disposed close to the connection line 4. Specifically, for example, as shown in FIGS. 8 and 9, if the connecting portion 22 b of the winding 22 of the lower coil 2 is made to make one turn along the inner periphery of the valve 1, the connecting portion 22 b is connected to the core 21. The portion located on the same side as the connection line 4 (left side in the examples of FIGS. 8 and 9) is a noise removal line. In FIG. 9, the second and subsequent rounds of the closely wound portion 22 a and the valve 1 are not shown, and the core 21 shows a cross section. If this configuration is adopted, the electromagnetic field generated by the connection line 4 is canceled out by the electromagnetic field generated by the noise removal line (the connecting portion 22b of the winding 22 of the lower coil 2), and thus radiated to the outside. Electromagnetic noise is reduced.

  Further, instead of using a ring-shaped core 21 as in the present embodiment, the core 21 includes a U-type core and an I-type core that forms a closed magnetic circuit between the U-type core and the U-type core. A UI-type core 21 (not shown) may be used. Alternatively, as shown in FIGS. 10A and 10B, the E-type core 21b and the I-type core 21c are connected to the E-type core 21b to form two closed magnetic paths between the E-type core 21b and the E-type core 21b. An EI core 21 may be used, and the coil 2 may have a shape surrounding the valve 1 at two locations.

  Further, in each coil 2, instead of connecting the closely wound portions 22a in series with each other via the connecting portion 22b as in this embodiment, the closely wound portions 22a are connected in parallel with each other as shown in FIG. May be. If this configuration is adopted, the inductance of the coil 2 as a whole is lower than when the closely wound portions 22a are connected in series, and the voltage to be applied to the coil 2 to generate a necessary electromagnetic field is reduced. This makes it easy to design a high-frequency power supply circuit.

It is explanatory drawing which shows arrangement | positioning of the close winding part of the coil | winding of a coil in embodiment of this invention. It is explanatory drawing which shows the whole structure same as the above. It is explanatory drawing which shows the state which connected the two coils mutually in parallel. (A) and (b) show different comparative examples. It is explanatory drawing which shows another form same as the above. It is explanatory drawing which shows another form same as the above. It is explanatory drawing which shows another form same as the above. It is explanatory drawing which shows another form same as the above. It is explanatory drawing which shows the wiring in the form of FIG. (A) (b) is explanatory drawing which shows another form same as the above, respectively, (a) (b) shows the example from which a number and arrangement | positioning of a densely wound part differ from each other. It is explanatory drawing which shows another form same as the above.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Valve | bulb 2 Coil 3 Instrument main body 4 Connection line 21 Core 22 Winding 22a Close winding part 22b Connection part

Claims (6)

Winding is wound in the poloidal direction around a bulb made of a light-transmitting material and having a ring shape and containing discharge gas, and a ring-shaped core made of a magnetic material and surrounding the bulb in the poloidal direction And at least one coil,
An electrodeless discharge lamp, wherein each coil is provided with a plurality of densely wound portions, each having a winding wound more densely than other portions, at equal intervals in the toroidal direction.   2. The electrodeless discharge lamp according to claim 1, wherein the closely wound portions are connected in parallel to each other. The winding has a connecting portion that connects the closely wound portions in series with each other,
2. The electrodeless discharge lamp according to claim 1, wherein the connecting portion is wound at least once around the core at a lower density than the densely wound portion.   2. The electrodeless discharge lamp according to claim 1, further comprising a connection line that includes two coils and that extends along the bulb to electrically connect windings of different coils.   5. The electrodeless discharge lamp according to claim 4, further comprising a noise removal line extending along the bulb on the same side as the connection line with respect to the coil and having a current flowing in a direction opposite to the current flowing in the connection line.   An electrodeless discharge lamp according to any one of claims 1 to 5, a high-frequency power source that supplies high-frequency power to a coil of the electrodeless discharge lamp, and an instrument body that houses the high-frequency power source. Lighting equipment to do.

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