JPH0794151A - Lighting device for electrodeless discharge lamp - Google Patents

Abstract

PURPOSE:To reduce the loss of an iron core while maintaining the luminous energy of a discharge lamp at the predetermined level or above by providing a part of the discharge lamp with a slender and small-diameter tube section, and externally coupling the iron core the small-diameter tube section for forming the magnetic path of flux. CONSTITUTION:An annular iron core 3 is externally coupled to the small- diameter tube section 2 of a discharge lamp 1. A primary coil 5 is wound around the core 3, and a high frequency power supply 6 is connected to the coil 5, thereby generating flux in the core 3. The discharge lamp 1 is, therefore, fitted to the core 3 like a chain, so as to constitute one turn of a secondary coil. As a result, discharge current flows to the discharge lamp 1 having interlinkage with the flux of the core 3, according to a principle similar to the case of a transformer for an ordinary discharge lamp having an electrode. Thus, the core 3 does not need to be enlarged, even when the discharge lamp 1 is made thick, and the loss of the core 3 can be restrained and kept at a low level.

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 lighting device in which a discharge lamp current is passed through a discharge lamp having no electrodes to light the discharge lamp.

[0002]

2. Description of the Related Art A conventional electrodeless discharge lamp lighting device is shown in FIG.
, The discharge lamp 21 is formed in a ring shape without a terminal, and the discharge lamp 21 is attached to the iron core 22 in a chain shape so that a magnetic flux is linked to the discharge lamp 21. There is one in which the discharge lamp 21 is turned on by turning on (eg, Japanese Patent Application No. 4-5146).

In this case, since there is no electrode, there is no filament loss and the tube current can be increased.

[0004]

By the way, in the case of the electrodeless discharge lamp lighting device, even if the tube current is increased, the light quantity of the discharge lamp 21 is proportional to the tube current if the surface of the tube coated with the phosphor is narrow. Therefore, it is necessary to increase the tube diameter of the discharge lamp 21. However, in the conventional case, as shown in FIG. 4, the discharge lamp 21 has the same thickness over its entire length. Therefore, if the tube diameter of the discharge lamp 21 is increased, the light amount of the discharge lamp 21 can be increased, but the iron core 22 Becomes large (the magnetic path length becomes long), which causes a problem that the loss of the iron core 22 increases.

In view of the above problems, the present invention is to reduce the loss of the iron core while maintaining the light quantity of the discharge lamp at a predetermined value or more.

[0006]

The technical means of the present invention for solving this technical problem is to make a magnetic flux interlink with a discharge lamp 1 having no termination so that a discharge lamp current flows through the discharge lamp 1. In the electrodeless discharge lamp lighting device configured as described above, a thin tube portion 2 formed thin is provided in a part of the discharge lamp 1, and an iron core 3 for forming the magnetic path of the magnetic flux is provided outside the thin tube portion 2. It is in the point where it is fitted.

[0007]

When a high frequency power source 6 is connected to the primary coil 5, a magnetic flux is generated in the iron core 3, the discharge lamp 1 links the magnetic flux with the iron core 3, and a discharge lamp current flows through the discharge lamp 1 so that the discharge lamp 1 Lights up.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the illustrated embodiments. In FIGS. 1 and 2, reference numeral 1 denotes an annular discharge lamp having no electrodes and having no termination, and gas components inside the discharge tube, mercury, etc. are electrodes. The structure is the same as that of a normal discharge lamp having a discharge lamp, and the inner surface of the discharge tube is coated with a phosphor. In a part of this discharge lamp 1,
A thin tube portion 2 formed thin is provided.

Reference numeral 3 denotes an annular iron core, which is fitted onto the thin tube portion 2 of the discharge lamp 1. A primary coil 5 is wound around the iron core 3, and a magnetic flux is generated in the iron core 3 by connecting a high frequency power source 6 to the primary coil 5. Therefore, the discharge lamp 1 is attached to the iron core 3 in a chain shape so as to form a one-turn secondary coil,
A discharge lamp current flows through the discharge lamp 1 which is linked to the magnetic flux of the iron core 3 according to the same principle as a transformer in a normal discharge lamp having electrodes.

[0010] Figure 3 shows another embodiment, a pair of auxiliary electrodes 7 to the discharge lamp 1 to assist in the discharge lamp current starts to flow is provided, 500KH _Z between the auxiliary electrodes 7, 500V
High-frequency power source 8 is connected to, and at both ends of the primary coil 5, together with the resonant capacitor 11 is connected, 500KH _Z via a ballast choke 12, a high frequency power source 6 of 50V are connected, release by the auxiliary electrode 7 After discharging the electric lamp 1, a discharge lamp current is caused to flow by interlinking with the magnetic flux of the iron core 3. The other points are the same as those of the above-mentioned embodiment.

[0011]

According to the present invention, a thin tube portion 2 formed thin is provided in a part of the discharge lamp 1, and an iron core 3 for forming the magnetic path of the magnetic flux is provided outside the thin tube portion 2. Since it is fitted, it is not necessary to enlarge the iron core 1 even if the discharge lamp 1 is formed thick, and the loss of the iron core 3 can be suppressed to a small value. Moreover, since most of the discharge lamp 1 can be formed thick, the light amount of the discharge lamp 1 can be maintained at a predetermined amount or more.

[Brief description of drawings]

FIG. 1 is a perspective view showing an embodiment of the present invention.

FIG. 2 is a plan sectional view of the same.

FIG. 3 is a configuration diagram showing another embodiment.

FIG. 4 is a configuration diagram showing a conventional example.

[Explanation of symbols]

 1 discharge lamp 2 thin tube part 3 iron core

Claims (1)

[Claims] 1. An electrodeless discharge lamp lighting device in which a magnetic flux is linked to an endless discharge lamp (1) to allow a discharge lamp current to flow through the discharge lamp (1). Partially thin tube part (2)
Is provided, and an iron core (3) for forming a magnetic path of the magnetic flux is externally fitted to the thin tube portion (2).