JPH0613190A - Electrodeless discharge lamp lighting device - Google Patents

Abstract

PURPOSE:To heighten the degree of coupling between a lighting coil and a plasma ring, and improve a lamp starting characteristic and utilization efficiency by making inner peripheral side cross sectional thickness of the lighting coil thinner than outer peripheral side cross sectional thickness. CONSTITUTION:This lighting device has an inverter to convert direct current electric power supply into high frequency electric power supply, an electrodeless discharge lamp 14 formed by sealing up dischargeable gas or vapor in a lamp tube 14a and a lighting coil 7A wound round the outer peripheral part of the lamp tube 14a. The lighting coil 7A lights the electrodeless discharge lamp 14 by inputting high frequency electric power to the lamp tube 14a through a plasma ring PR in the lamp tube 14a being coupled magnetically with this lighting coil 7. Since inner peripheral side cross sectional thickness (h1) of the lighting coil 7A on the plasma ring PR formed side is made thinner than outer peripheral side coil cross sectional thickness (h2), magnetic flux generated by an electric current flowing in the lighting coil 7A is concentrated on the plasma PR side, so that the degree of coupling is heightened.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrodeless discharge for lighting a lamp by supplying high frequency power from a lighting coil wound around the electrodeless discharge lamp to a plasma ring in the lamp which is magnetically coupled. The present invention relates to a lamp lighting device, and more particularly, to an electrodeless discharge lamp lighting device improved so as to increase the degree of coupling between a lighting coil and a plasma ring.

[0002]

2. Description of the Related Art In an electrodeless discharge lamp, a lamp body (outer tube) made of quartz glass is formed in a spherical shape, and for example, krypton gas or a luminescent metal that vaporizes when excited is enclosed in the lamp body. In this electrodeless discharge lamp, a lighting coil is wound around the lamp body for several turns (about 1 to 3 turns), and a high frequency current of a short wave band of several MHz or more is passed through the lighting coil. The discharge gas or vapor in the lamp body is excited to form a plasma ring that is magnetically coupled to the coil.
As a result, high-frequency power is supplied from the lighting coil to the plasma ring in the lamp body that is magnetically coupled, and the electrodeless discharge lamp is lit at high frequency. Such an electrodeless discharge lamp has excellent characteristics such as high efficiency, high brightness, high color rendering, and long life.

FIG. 10 shows an overall configuration of a general lighting device for lighting the electrodeless discharge lamp. In this figure, the commercial AC power supply 1 is converted into a DC power supply by being rectified and smoothed by a rectifier circuit 2, and then converted into a high frequency power supply of 13.56 MHz by an inverter 3. The inverter 3 is formed in a half bridge type including switching elements 5a and 5b driven by a drive circuit 4. Between the output terminals of this inverter 3,
A lighting coil 7 is connected via a variable capacitor 6, and a capacitor 8 is connected in parallel to the lighting coil 7 which constitutes a main circuit. The lighting coil 7 is wound around the lamp for several turns. Here, the capacitors 6 and 8 form a resonance circuit with the lighting coil 7, and perform impedance correction for matching the high frequency power supply and the lamp load. Further, the lighting coil 7 is connected in parallel with a starting circuit 13 including a capacitor 9, a parallel resonance circuit portion of the starting coil 10 and the capacitor 11, and a series circuit of a starting switch 12. The high voltage generation point, which is the connection point between the capacitor 9 and the parallel resonant circuit, is the gas probe 14 of the lamp 14.
connected to b. Here, the capacitors 9 and 11 are used for tuning, and by changing the degree of resonance of the starting circuit 13 by the capacitors 9 and 11, the distribution of power to the main circuit and the starting circuit 13 is changed, or the starting circuit is operating. It has a function of matching the combined impedance of the main circuit and the starting circuit 13 in the high frequency power supply. The electrodeless discharge lamp 14 has a main tube 14a serving as an arc tube filled with about 250 torr of krypton gas (Kr) serving as a discharge gas, and NaI, CeI, and the like. From the top of the main tube 14a, a gas probe 14b forming a starting energy injection pipe section separated from the main tube 14a by a partition wall extends. Krypton gas is enclosed in the probe 14b at about 10 torr.

In the electrodeless discharge lamp lighting device configured as described above, when the switch 12 is turned on at the time of starting to supply high frequency power from the inverter 3 to the main circuit and the starting circuit 13, the high voltage generated in the starting circuit 13 is generated. Gas probe 14
applied to b. As a result, the gas in the gas probe 14b is destroyed by the discharge, and the gas in the main tube 14a is brought into a glow discharge state.
A plasma ring is formed therein. When the formation of the plasma ring is detected by a detection circuit (not shown), the start switch 12 is turned off in response to the detection signal.
After that, lighting power is supplied from the lighting coil 7 to the magnetically coupled plasma ring, and the lamp 14 is lit at high frequency.

[0005]

As described above, the lighting coil 7 forms a plasma ring in the main tube 14a, maintains the formed plasma ring, and magnetically couples with the plasma ring. It has a function of inputting high frequency power into the main tube 14a. FIG. 9 schematically shows a magnetic flux φ formed when a current flows through the lighting coil 7 and a plasma ring PR formed in the main tube 14a by the magnetic flux φ. In the conventional lighting device, the cross-sectional shape of the lighting coil 7 is not specified, and it cannot be said that the degree of coupling between the coil 7 and the plasma ring PR is sufficiently high. For this reason, the thickness d2 of the surface on which the plasma ring PR is formed is increased, the concentration of high-frequency energy input into the main tube 14a is weak, and the light output of the lamp 14 cannot be sufficiently increased.

The present invention has been proposed in order to solve the problems of the prior art, and the degree of coupling between the lighting coil and the plasma ring can be increased to improve the starting characteristics of the lamp. An object of the present invention is to provide an electrodeless discharge lamp lighting device that can improve the efficiency of the lamp.

[0007]

In order to achieve this object, the present invention provides an inverter for converting a DC power supply into a high frequency power supply, and an electrodeless discharge lamp in which at least a discharge gas or vapor is sealed in a lamp tube. , For example, has a lighting coil wound around the outer periphery of the lamp tube and supplied with high frequency power from the inverter, and supplies high frequency power through a plasma ring in the lamp tube that is magnetically coupled to the lighting coil. In a lighting device that lights an electrodeless discharge lamp by inputting into the lamp tube, the inner peripheral side cross-sectional thickness of the above-mentioned lighting coil on the side where the plasma ring is formed is thinner than the coil cross-sectional thickness on the outer peripheral side. It has been configured.

Further, in the present invention, the resistance value of the metal material forming the inner peripheral side of the lighting coil is made smaller than the resistance value of the metal material forming the outer peripheral side.

Further, in the present invention, the cross-sectional thickness on the inner peripheral side of the lighting coil is made smaller than the cross-sectional thickness on the outer peripheral side, and the resistance value of the metal material forming the inner peripheral side of the lighting coil is The resistance value is smaller than the resistance value of the metal material forming the outer peripheral side.

[0010]

According to the above structure, the magnetic flux generated by the current flowing through the lighting coil is concentrated on the plasma forming side, and the degree of coupling between the plasma ring and the coil current is increased.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Specific embodiments of the electrodeless discharge lamp lighting device according to the present invention will be described in detail below with reference to the drawings. FIG. 1 shows a lighting coil and an electrodeless discharge lamp according to the present invention. This electrodeless discharge lamp can be lit by using the lighting device described in FIG. In this figure, the lighting coil 7A is wound one turn around the outer peripheral portion of the main tube 14a forming the outer tube of the electrodeless discharge lamp 14. When a high-frequency current is passed from the inverter 3 to the lighting coil 7A, the discharge gas or vapor in the main tube 14a is excited, a plasma ring PR is formed in the main tube 14a, and the lighting coil 7A and this plasma ring are formed. Magnetically coupled with PR. The lighting coil 7A has a cross-sectional shape that is sharpened toward the inner circumference side, and the cross-sectional thickness h1 on the inner circumference side of the lighting coil 7A on the side where the plasma ring PR is formed is the coil on the outer circumference side. It is designed to be thinner than the sectional thickness h2. Since the lighting coil 7A has such a cross-sectional shape, the coil 7A can be operated when a current is applied to the coil 7A as shown in FIG.
The magnetic flux φ formed around is sharper concentrated on the inner peripheral side, has a small thickness d1, and has a high density.
Are concentrated in the central portion of the main tube 14a. In the figure, A indicates the direction of the coil current. This enhances the degree of magnetic coupling between the plasma ring PR and the coil current.

Next, a lighting coil 7B of another embodiment shown in FIG. 3 will be described. In this embodiment, the inner peripheral side cross-sectional shape of the coil 7B is made thinner than that of the outer peripheral side, and the inner peripheral coil material M2 is made of copper. To reduce the resistance value. Due to the dust, the concentration of magnetic flux on the inner circumference side of the coil is further increased, and
Plasma ring PR and lighting coil 7 formed in a
The degree of bonding with B can be increased.

Next, a lighting coil 7C of still another embodiment shown in FIG. 4 will be described. In this embodiment, the lighting coil 7C wound around the outer peripheral portion of the main tube 14a has two
The coil is a turn, and the tip of each coil portion on the inner circumferential side is sharpened so that the cross-sectional thickness h1 on the inner circumferential side of the coil is thinner than the cross-sectional thickness h2 on the outer circumferential side.

Further, the lighting coil 7D shown in FIG. 5 is formed by winding 3 turns around the outer circumference of the main tube 14a, and the cross-sectional thickness h of the inner circumference of each coil is the same as in FIG.
The cross-sectional shape of the coil 7D is determined so that 1 is thinner than the cross-sectional thickness h2 on the outer peripheral side.

Next, a lighting coil 7E of still another embodiment shown in FIGS. 6 and 7 will be described. In this embodiment, the lighting coil 7E and the capacitor 8 connected in parallel to the coil 7E are integrally formed of an aluminum plate. By bending the aluminum plate, a 2-turn lighting coil 7 is provided on the outer peripheral portion of the main tube 14a.
E is formed. Inner circumference J of this lighting coil 7E
1 is sharper than the outer peripheral portion J2 so that the degree of coupling between the coil 7E and the plasma ring can be increased.

In each of the embodiments described above, the main tube 14
Although the lighting coil is wound around the outer peripheral portion of a, when the lighting coil is arranged in the main tube 14a, the side where the plasma ring PR is formed is the coil 7 as shown in FIG.
It is on the outer peripheral side of F. In this case, the cross-sectional thickness h of the coil outer circumference side
The outer peripheral side of the coil 7F is sharpened so that 2 is thinner than the sectional thickness h1 on the inner peripheral side.

In each of the lighting coils shown in FIGS. 4 to 8, the coil portion on the side where the plasma ring PR is formed is made of a material having a resistance value lower than that of the coil portion on the opposite side. Good.

[0018]

As described above, according to the present invention, since the degree of coupling between the lighting coil and the plasma ring formed in the lamp tube can be increased, the starting characteristics of the electrodeless discharge lamp can be improved as compared with the conventional case. In addition to being able to improve the efficiency, the efficiency of the lamp can be improved, so that the light output when the same power is applied can be increased.

[Brief description of drawings]

FIG. 1 is a perspective view showing a lighting coil and a lamp tube used in an electrodeless discharge lamp lighting device according to the present invention.

FIG. 2 is a vertical sectional view schematically showing a sectional shape of a lighting coil and a plasma ring formed in a lamp tube.

FIG. 3 is a diagram showing a cross-sectional shape of another lighting coil.

FIG. 4 is a view showing a sectional shape of still another lighting coil.

FIG. 5 is a view showing a sectional shape of still another lighting coil.

FIG. 6 is a plan view of a specific lighting coil.

FIG. 7 is a side view showing the lighting coil of FIG. 6 with a part thereof cut away.

FIG. 8 is a schematic explanatory view showing another embodiment in which the lighting coil is arranged in the lamp tube.

FIG. 9 is a view showing a cross-sectional shape of a conventional lighting coil.

FIG. 10 is a circuit diagram showing an overall configuration of a general electrodeless discharge lamp lighting device.

[Explanation of symbols]

1 Commercial AC power supply 2 Rectifier circuit 3 Inverter 7, 7A, 7B, 7C, 7D, 7E, 7F Lighting coil 13 Starting circuit 14 Electrodeless discharge lamp 14a Main tube PR Plasma ring

Claims (3)

[Claims] 1. An inverter for converting a direct-current power supply into a high-frequency power supply, an electrodeless discharge lamp in which at least a discharge gas or vapor is sealed in a lamp tube, and an inverter arranged near or in the lamp tube. A non-electrode discharge lamp by inputting high-frequency power into the lamp tube through a plasma ring in the lamp tube that is magnetically coupled to the lighting coil. A lighting device for lighting an electrodeless discharge lamp lighting device, wherein a cross-sectional thickness of the lighting coil on the side where ring plasma is formed is smaller than a cross-sectional thickness of the coil on the opposite side. 2. An inverter for converting a direct-current power supply into a high-frequency power supply, an electrodeless discharge lamp in which at least a discharging gas or vapor is sealed in a lamp tube, and the inverter arranged near or in the lamp tube. A non-electrode discharge lamp by inputting high-frequency power into the lamp tube through a plasma ring in the lamp tube that is magnetically coupled to the lighting coil. In the lighting device for lighting the electrode, the resistance value of the constituent metal material of the lighting coil on the side where the ring plus is formed is made smaller than the resistance value of the coil constituent metal material on the opposite side. Discharge lamp lighting device. 3. An inverter for converting a direct-current power supply into a high-frequency power supply, an electrodeless discharge lamp in which at least a discharge gas or vapor is sealed in a lamp tube, and the inverter arranged near or in the lamp tube. A non-electrode discharge lamp by inputting high-frequency power into the lamp tube through a plasma ring in the lamp tube that is magnetically coupled to the lighting coil. In the lighting device for lighting, the cross-sectional thickness of the above-mentioned lighting coil in which ring plasma is formed is made smaller than the cross-sectional thickness of the coil on the opposite side, and
The resistance value of the coil constituent metal material on the side where the cross-sectional thickness is thinned,
An electrodeless discharge lamp lighting device characterized by being made smaller than the resistance value of the metal material of the coil on the opposite side.