JPH0722183A - Excitation coil, electrodeless lamp lighting device and lighting device - Google Patents

Abstract

PURPOSE:To enhance the electric power efficiency when an electromagnetic energy is supplied to an electrodeless lamp. CONSTITUTION:A wire 81 having flat section is wound one turn or more so that an excitor coil 8 is formed. If the thickness of the wire section is increased, the coil resistance increases to worsen the efficiency, while an enlargement of the wire width, on the contrary, causes decrement of the coil resistance but lessens the coupling factor between an electrodeless lamp 10 and the excitor coil 8 to lead to worsening of the efficiency. Therefore, the width-to-thickness ratio of the section of the wire 81 is made between 2-8 so that the coupling factor is enlarged over the increment of the coil resistance, and the efficiency when the electromagnetic energy is supplied from the excitor coil 8 to the electrodeless lamp 10 is enhanced compared with any conventional arrangement.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrodeless discharge lamp, and more particularly to an excitation coil for electromagnetically coupling the electrodeless lamp to supply electromagnetic energy to the electrodeless lamp, and an electrodeless lamp using this excitation coil. The present invention relates to a lighting device and a lighting device.

[0002]

2. Description of the Related Art A conventional electrodeless lamp lighting device for lighting an electrodeless lamp has a structure as shown in FIG. The rectifier circuit 2 converts an AC voltage supplied from the commercial power supply 1 into a predetermined DC voltage and supplies the DC voltage to a high frequency current generation circuit composed of FETs 4 and 5. The FETs 4 and 5 are switched under the control of the drive circuit 3 to generate a high frequency current, which is supplied to the excitation coil 8 via the matching capacitor C1. Initially, the switch 11 is turned on, the high-frequency current flows to the series resonance circuit 6 side, and a high-voltage current is applied from the series resonance circuit 6 to the gas probe 9 of the electrodeless lamp 10 to generate the electrodeless lamp 10.
A rare gas in the electrodeless lamp 10 is ionized by causing a corona discharge therein. Then, when electromagnetic energy is started to be injected into the electrodeless lamp 10 from the excitation coil 8 and an arc ring is formed in the electrodeless lamp 10,
The switch 11 is turned off, and after the arc ring and the excitation coil 8 are electromagnetically coupled to each other, the electrodeless lamp 10 is glow-arc transferred and lights up with all light.

As described above, the excitation coil 8 electromagnetically coupled to the arc ring in the electrodeless lamp 10 to supply electromagnetic energy into the lamp has a shape as shown in FIG. 6, for example. 6A is a partial cross-sectional side view of the excitation coil 8, and FIG. 6B is a plan view of the excitation coil 8. The excitation coil 8 is formed by winding a winding wire 81 having a flat cross section in a two-turn ring shape. Therefore, the winding 81 of the excitation coil 8 has two layers, and in the example of FIG. 6A, the windings 81 are arranged such that the surfaces of the windings 81 are inclined with respect to each other, and there is no electrode at the center of the excitation coil 8. The light-shielding degree of the lamp 10 is reduced. In such an excitation coil 8, as shown in FIG. 6 (A), the cross-sectional width of the winding 81 is set so that the skin current path for passing the high frequency current is made as wide as possible and the light shielding degree of the lamp 10 is made small. And the thickness ratio has been determined.

By the way, when an electric current is passed through the winding 81 having the above-mentioned flat cross-sectional shape which constitutes the exciting coil 8, the radius of the current center is wide when the inner radius of the coil is constant. The larger the outer radius of the coil, the larger. When the outer radius of the coil increases in this way, the current center of the arc ring (secondary coil) formed in the electrodeless lamp 10 and the current center of the excitation coil 8 are separated from each other. Therefore, the wider the winding 81, the lower the degree of coupling between the electrodeless lamp 10 and the excitation coil 8 and the efficiency (electromagnetic energy from the excitation coil 8 is transferred to the electrodeless lamp 10).
There is a tendency that the efficiency of supplying the liquid inside) decreases. On the other hand, when the width of the cross section of the winding 81 is narrowed and the thickness thereof is increased, that is, when the width of the cross section of the winding 81 and the dimension of the thickness are not so different, the winding 81 is disconnected. Since the surface area per area becomes small and the skin current path at high frequency becomes narrow, the coil resistance increases and the efficiency decreases (due to resistance loss). Therefore, if the ratio of the width and the thickness of the cross section of the winding 81 is adjusted, there is a ratio in which the electromagnetic energy can be most efficiently injected from the excitation coil 8 into the electrodeless lamp 10. However, conventionally, since the thickness and width of the cross section of the winding 81 were determined without taking such matters into consideration, there was room for improving the efficiency of the electrodeless lamp lighting device. In addition, in the conventional excitation coil shown in FIG.
The width / thickness of the cross section of the winding wire 81 was about 9.0.

[0005]

The shape of a conventional excitation coil that electromagnetically couples to an arc ring formed in an electrodeless lamp to supply electromagnetic energy into the electrodeless lamp, particularly the width of the winding forming the coil. The thickness ratio was designed mainly to reduce the coil resistance so that a high-frequency current flows through this coil as much as possible, and to reduce the light shielding degree of the electrodeless lamp. There was room for improvement in the efficiency of supplying electromagnetic energy between the electrode lamps.

In view of the above circumstances, it is an object of the present invention to provide an excitation coil capable of further improving the efficiency of supplying electromagnetic energy to an electrodeless lamp.

[0007]

The excitation coil of the present invention comprises:
The ratio H / W of the width H and the thickness W of the flat cross section is 2 to
It has a structure in which the winding wire of No. 8 is wound in the shape of a plurality of turns of one turn or more.

[0008]

In the excitation coil of the present invention, when the ratio of the width and thickness of the cross section of the winding forming the excitation coil is set to about 3.5, the coil resistance increases to some extent, but the excitation coil and the electrodeless lamp are further increased. It is possible to improve the coupling coefficient with and to improve the efficiency of supplying electromagnetic energy from the excitation coil to the electrodeless lamp more than ever before.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a diagram showing an embodiment of an excitation coil of the present invention, FIG. 1 (A) is a partial cross-sectional side view of the excitation coil of the present invention, and FIG. 1 (B) is a plan view of the excitation coil of the present invention. It is a figure. The excitation coil 8 is formed by winding a winding wire 81 having a flat cross section in a two-turn ring shape. Therefore, the winding 81 of the exciting coil 8 has two layers, and in the example of FIG. 1A, the windings 81 are arranged so that the surfaces of the windings 81 are inclined with respect to each other, and there is no electrode at the center of the exciting coil 8. The light-shielding degree of the lamp 10 is reduced.

By the way, as described in the conventional example, when a high-frequency current is passed through the winding 81 having the above-described flat cross-section forming the excitation coil 8, the radius of the current center is the inner circumference of the coil. When the radius is constant, the winding 81
The larger the width (section width) of the coil and the larger the outer radius of the coil, the larger. Therefore, as the width of the winding 81 becomes wider, the current center of the arc ring (secondary coil) and the current center of the excitation coil 8 are separated from each other. Therefore, the wider the winding 81, the lower the degree of coupling between the electrodeless lamp 10 and the excitation coil 8 and the tendency that the electromagnetic energy supply efficiency decreases. On the other hand, when the width of the winding 81 is narrowed and the thickness of the winding 81 (the thickness of the cross section) is increased, there is not much difference between the width and the thickness of the winding 81, and the winding 81 is disconnected. Since the surface area per area becomes small and the skin current path at high frequency becomes narrow, the coil resistance increases and the efficiency (due to resistance loss) decreases.

Therefore, if the width of the winding 81 is too wide,
The characteristic that the degree of coupling between the electrodeless lamp 10 and the excitation coil 8 is reduced, and when the width of the winding 81 is narrowed and the thickness thereof is increased, the skin current path is narrowed and the coil resistance is increased. There is. In consideration of this point, in this example, the winding 81 has a thickness of 2 mm, the width thereof is 7 mm, and the ratio of the width and the thickness of the winding 81 is 3.5.
The width-thickness ratio is 9.0 in the conventional example, and when the width / thickness is 3.5 as in this example as compared with such a shape, the thickness of the winding 81 becomes thicker, Although the coil resistance is increased by 10% as compared with the conventional example, the width is narrowed, and the coupling coefficient with the electrodeless lamp 10 is improved by 3.3% as compared with the conventional example. Electrode lamp 10
The efficiency of supplying electromagnetic energy to the can be improved as compared with the conventional case.

According to the present embodiment, the coupling coefficient between the excitation coil 8 and the electrodeless lamp 10 is increased by making the width-thickness ratio of the excitation coil 8 smaller than in the conventional case within a range in which the coil resistance is not increased so much. Therefore, the efficiency of supplying electromagnetic energy from the excitation coil 8 to the electrodeless lamp 10 can be improved as compared with the conventional case. Therefore, the electrodeless lamp 10 can be illuminated brighter with the same power, and the electrodeless lamp 10 can be illuminated with less power when the illuminance is the same. In the above-described embodiment, the width-thickness ratio of the winding 81 is set to 3.5, but if the numerical value is in the vicinity of this, substantially the same effect can be obtained.

The cross-sectional shape of the winding 81 forming the exciting coil 8 can be various shapes such as an elliptical shape.
In this case as well, the width and thickness of the cross section of the winding 81 are equivalently obtained, and by setting width / thickness = about 3.5, the efficiency in supplying electromagnetic energy from the excitation coil 8 into the electrodeless lamp 10 is improved. Can be improved.

FIG. 2 shows another embodiment of the present invention. The excitation coil 8 of this example is also formed by winding a winding wire 81 having a flat cross section as shown in FIG. 2A in a two-turn ring shape as shown in FIG. 2B. However, in this example, FIG.
As shown in (A), the surfaces of the windings 81 wound in two layers are arranged in parallel. Also in this example, the ratio of the width to the thickness of the winding 81 is set to about 3.5 to improve the efficiency in supplying electromagnetic energy from the excitation coil 8 to the electrodeless lamp (not shown), and the same effect as in the previous embodiment. There is.

FIG. 3 is a diagram showing still another embodiment of the present invention. The excitation coil 8 of this example also has a winding 81 having a flat cross section and bent in the middle as shown in FIG. 3 (A).
As shown in (B), it is formed by winding in a two-turn ring shape. However, in this example, as shown in FIG. 3A, some surfaces of the winding 81 wound in two layers are parallel to each other, and the remaining surfaces are arranged to be inclined to each other. Also in this example, the efficiency of supplying electromagnetic energy from the excitation coil 8 to the electrodeless lamp (not shown) is improved by setting the width-to-thickness ratio of the winding 81 to about 3.5, which is the same as the previous embodiment. effective. However, the width of the winding 81 in this example is a + b in the drawing. The ratio of the width H to the thickness W of the flat section of the winding used in the excitation coil of the present invention is 3.
The number is not limited to 5, and may be 2 to 8.

FIG. 4 is a circuit diagram showing an embodiment of the lighting device of the present invention. This corresponds to claim 3, and the reflector 2
By providing 0, the light beam generated from the electrodeless lamp 10 can be directed in a specific direction. Further, when the reflection plate 20 is removed, it becomes an embodiment of the electrodeless lamp lighting device corresponding to the second aspect. Since the excitation coil 8 shown in FIG. 4 is formed by using the winding having the width-to-thickness ratio of 3.5 as described above, the efficiency of the device is improved.

[0017]

As described above, according to the excitation coil of the present invention, the power efficiency when supplying electromagnetic energy to the electrodeless lamp can be further improved.

[Brief description of drawings]

FIG. 1 is a diagram showing an embodiment of an excitation coil of the present invention.

FIG. 2 is a diagram showing another embodiment of the present invention.

FIG. 3 is a diagram showing still another embodiment of the present invention.

FIG. 4 is a circuit diagram showing an embodiment of a lighting device of the present invention.

FIG. 5 is a circuit diagram showing an embodiment of a conventional electrodeless lamp lighting device.

FIG. 6 is a diagram showing an example of a conventional excitation coil.

[Explanation of symbols]

8 ... Excitation coil 10 ... Electrodeless lamp 81 ... Winding

Claims (3)

[Claims] 1. A winding having a ratio H / W of a width H and a thickness W of a flat cross section of 2 to 8 is wound into one or more turns in a ring shape. Excitation coil to. 2. The excitation coil according to claim 1, a high-frequency power supply circuit that supplies a high-frequency current to the excitation coil, and an electrodeless lamp that is electromagnetically coupled to the excitation coil to turn on. An electrodeless lamp lighting device. 3. The excitation coil according to claim 1, a high-frequency power supply circuit for supplying a high-frequency current to the excitation coil, an electrodeless lamp that is electromagnetically coupled to the excitation coil to turn on, and an electrodeless lamp. An illuminating device, comprising: a reflector that reflects emitted light rays.