JPH0498754A - Discharge lamp - Google Patents

Abstract

PURPOSE:To realize a low noise lighting fixture by applying the constitution wherein magnetic field generated due to outflowing current through an electric circuit is concentric and offset with another magnetic field generated due to incoming current. CONSTITUTION:A slender tube body la with one end open to a tube body 1 and the other end closed is laid concentrically at the center of the tube body l having circular section and both ends closed. In addition, an electrode f1 is provided inside the closed end of the aforesaid slender tube body la, and an electrode f2 is fitted concentrically with the aforesaid electrode f1 within the end of the tube body l at the closed end of the slender tube body la, thereby constituting a discharge lamp. In this state, when high voltage is applied from a ballast circuit 2 to a gap between the concentrically laid electrodes f1 and f2 for generating electric discharge, lamp current Ib flows within the tube body l enclosing the slender tube body la in such a way as enclosing the current Ia concentrically, and in a reverse direction. According to the aforesaid construction, magnetic fields generated with both currents Ia and Ib offset each other, thereby enabling a radiation noise due to the currents through the discharge lamp to be lowered and wave disturbance to be restrained.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a discharge lamp that is lit using a high frequency power source.

[Prior Art] Conventionally, a discharge lamp such as a straight fluorescent lamp as shown in FIG. 6 is provided with electrodes ff2 at both ends of a tube body 1, and a ballast circuit 2 connects an input power source 3 to the discharge lamp for lighting the discharge lamp. A voltage is applied to convert the lamp into a voltage suitable for lighting, and the lamp is lit, and the lamp current is limited to a current value suitable for lighting.

By the way, when a circuit that performs high frequency conversion is used as the ballast circuit 2, the tube body 1, the ballast circuit 2, and the electrode f5
．． There is a problem in that the high frequency noise radiated from the lamp connection line 4 connecting f2 is likely to be radiated to the outside and interferes with equipment 5 such as a radio.

Conventionally, the following measures have been taken to deal with such problems. In other words, since power is supplied from the ballast circuit 2 to a discharge lamp having a finite size, the harmonic component of the high frequency energy generated by the ballast circuit 2 is suppressed to reduce the level of radiation to the outside.

[Problems to be Solved by the Invention] However, since no countermeasures against radiant noise have been taken for the discharge lamp itself, there is still a problem that troubles caused by radiant noise cannot be improved, especially in large discharge lamps or discharge lamps that flow a large lamp current. Ta.

Furthermore, as shown in Fig. 7, in a discharge lamp having a U-shaped tube body 1, the lamp current flowing from the ballast circuit 2 is in opposite directions such as Ib and Ia in parallel discharge paths, so that it is not normally radiated. However, as the frequency increases, the position of the magnetic field component generated by the lamp currents 1a and Ib at the position of the disturbed device 5 is reduced. There is a problem in that the reduction effect is reduced due to the phase difference, and conventional discharge lamps have a problem in that a high reduction effect cannot be obtained.

The present invention has been made in view of the above problems, and its purpose is to provide a discharge lamp that can reduce radiation noise with high efficiency even when a high frequency power source is used in the ballast circuit.

[To solve the problem of 11ff] In order to achieve the above-mentioned object, the invention according to claim 1 is a discharge lamp with electrodes, in which a lamp current conduction path is formed by folding back, and the current flowing in the outgoing path of the current conduction path is generated. The magnetic field and the magnetic field generated by the current flowing in the return path are concentric circles and cancel each other out.

Further, the invention as claimed in claim 2 is an electrode discharge lamp in which two discharge paths having substantially the same specifications are tightly integrated, and the directions of lamp currents flowing through both discharge paths are opposite to each other.

[Function] According to the invention as claimed in claim 1, the energizing path for the lamp current is formed by folding back, and the magnetic field generated by the current flowing in the outward path of the energizing path and the magnetic field generated by the current flowing in the returning path are concentric circles. Moreover, since they cancel each other out, it is possible to generate concentric magnetic fields that cancel each other out, and as a result, the lamp itself can suppress radiation noise, and even if a high frequency generation circuit is used in the ballast circuit, low noise lighting can be achieved. The instrument can be realized.

In the invention as claimed in claim 2, the two discharge paths having substantially the same specifications are closely integrated, and the directions of the lamp currents flowing through both discharge paths are opposite to each other, so that radiation noise can be reduced even in two lamps. As a result, a low-noise two-light fixture can be realized.

[Example] The present invention will be explained below with reference to Examples.

As shown in FIG. 1(a), this embodiment has a tubular body 1 whose cross section is circular with both ends closed, and one end is open to the tubular body 1 at the center.
A capillary body 1a whose other end is closed is disposed concentrically, an electrode f1 is disposed within the other end of the capillary body 1a, and an electrode f1 is disposed within the end of the tubular body 1 on the other end side of the capillary body 1a. The above electrode f1
A discharge lamp is constructed by arranging electrodes f2 in a concentric circle with the center at the center.

Then, when a high frequency voltage from the ballast circuit 2 is applied to the electrodes f+ and f2rMJ arranged concentrically to cause discharge,
The capillary body 1
As shown in FIG. 1(b), the lamp current (b) flows in the tube 1 surrounding the tube (a) in a concentric circle and in the opposite direction.

Therefore, the magnetic fields generated by both currents 1a and Ib cancel each other out, and the total strength of the magnetic fields inside and outside the concentric circle at the point of the disturbed device 5 can be the same even if the distance changes, and as a result, the discharge lamp Radiation noise due to flowing current can be reduced, and interference can be suppressed.

In the first embodiment, the forward path of the energization path through which the lamp current flows,
Both return paths are formed by discharge paths, but in this embodiment, as shown in FIG. At the same time, an electrode f2 is arranged concentrically around the electrode support 6 at one end of the tube body 1, and a conductor wired inside the electrode support 6 is used for the outgoing or returning path of the lamp current conduction path. It is formed at 7.

When a high frequency voltage from the ballast circuit 2 is applied between the concentrically arranged electrodes f, f2 to cause a discharge, a lamp current 1b flows through the discharge path in the tube l with respect to the current Ia flowing through the conductor 7. flow in opposite directions surrounding the concentric circles.

Therefore, as in Example 1, the magnetic fields generated by both currents Ia and Ib cancel each other out, and the total strength of the magnetic fields inside and outside the concentric circle at the point of the disturbed device 5 is the same even if the distance changes. Therefore, the generation of radiation noise due to the current flowing through the discharge lamp can be reduced, and interference can be suppressed.

In this embodiment, as shown in FIG. 3(a), a reciprocating discharge path is formed by folding back one tube 1, and by twisting the parallel discharge paths, the discharge path shown in FIG. In (b), the cross-sectional shape changes depending on the position of the cross-section, as shown by the solid line and the broken line, and when all the cross-sections are integrated, they form a concentric circle. In this case as well, as in Example 1.2 above, the lamp currents flowing in the forward and backward discharge paths are in opposite directions,
The magnetic fields generated by both lamp currents are canceled out, and the generation of radiation noise can be reduced.

In this embodiment, as shown in Fig. 4, two tube bodies IAIB are brought close to each other in parallel and twisted together in a spiral to integrate them, and both tube bodies IA and IB are independent lamps. and 2
By flowing the lamp currents from the lamp ballast circuit 2 so that the directions of the lamp currents are opposite to each other,
Both tubular bodies IA.

The magnetic fields generated by the lamp current flowing through 1B cancel each other out, making it possible to reduce the generation of radiation noise.

Incidentally, as shown in FIG. 5, the generation of radiation noise can be similarly reduced by using the annular tubes IA and IB.

In these cases, if the tubes IA and IB have the same size, length, and lamp current, or have substantially the same specifications, the radiation noise can be greatly reduced.

[Effects of the Invention] In the present invention, the lamp current conduction path is formed by folding back, so that the magnetic field generated by the current flowing in the forward path of the current path and the magnetic field generated by the current flowing in the return path are concentric and cancel each other out. As a result, it is possible to generate concentric magnetic fields that cancel each other out, and as a result, radiation noise can be suppressed in the lamp itself, making it possible to realize a low-noise lighting fixture even if a high-frequency generation circuit is used in the ballast circuit. It has the effect of being able to

In addition, the invention as claimed in claim 2 closely integrates two discharge paths with substantially the same specifications, and the directions of the lamp currents flowing through both discharge paths are opposite to each other, thereby reducing radiation noise even in two lamps. This has the effect of realizing a two-light fixture with low noise.

[Brief explanation of the drawing]

FIGS. 1(a) and (b) are a schematic configuration diagram and a top view of Embodiment 1 of the present invention, FIG. 2 is a schematic configuration diagram of Embodiment 2 of the present invention, and FIGS. 3(a) and (b) 4(a) and 4(b) are schematic configuration diagrams and a cross sectional view of Embodiment 4 of the present invention, and FIG. 5 is a side view and cross sectional view of Embodiment 3 of the present invention. The side view of the example, FIGS. 6 and 7 are schematic configuration diagrams of the conventional example, respectively. 1 is a tube body, 1a is a thin tube body, 2 is a ballast circuit, f2 is an electrode, and LA and IB are tube bodies. Agent Patent Attorney Ishi 1) Chief 7 Figure 3 Figure 4 Figure 5 Figure 6 Figure 7

Claims (2)

[Claims] (1) In an electroded discharge lamp, the lamp current conduction path is formed by folding back, so that the magnetic field generated by the current flowing in the forward path of the current path and the magnetic field generated by the current flowing in the return path are concentric circles and cancel each other out. A discharge lamp characterized by: (2) In electrode discharge lamps, two with almost the same specifications
A discharge lamp characterized in that two discharge paths are closely integrated, and the directions of lamp current flowing in both discharge paths are different and opposite directions.