JPH022267B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Technical Field) The present invention relates to a low pressure discharge lamp device using a low pressure discharge lamp such as a fluorescent lamp.

(Background Art) Generally, in a fluorescent lamp, ultraviolet light generated from a discharge path passing through the center of the tube is converted by a phosphor coated on the inner wall of the tube into visible light having a characteristic color of the phosphor, and then emitted. A conventional example of such a lamp is shown in FIG. In the figure, 1 is a glass tube, 2 is a phosphor coating, 3 is an airtight space filled with a predetermined amount of mercury and a rare gas, 4 is a filament filled with an emitter, 5 is a lead wire, 6 is a glass stem, and 7 is the base. In such a lamp, the position of the discharge path is substantially constant under normal lighting conditions, and the emitted light color is limited to only one type.

Furthermore, unlike the above-mentioned general fluorescent lamps, various fluorescent lamps have been proposed in which the light distribution characteristics or emission color can be changed with a single lamp.

FIG. 2 shows an example of such a fluorescent lamp, which differs from the general fluorescent lamp described above in that a cylindrical discharge path regulating body 8 is disposed inside the tube.
A magnet 9 is disposed outside the tube, and the phosphor 2 coated on the inner surface of the glass tube 1 is coated with a plurality of phosphors 2a and 2b of different luminescent colors, so that the other configurations are different from each other. Since the configuration is similar to that shown in FIG. 1, the explanation will be omitted by assigning the same reference numerals to the equivalent configurations.

Next, the principle of operation of the above fluorescent lamp will be explained with reference to FIG. When a magnetic field perpendicular to the tube axis direction is applied using the magnet 9 as shown in FIG. (For example, 200 Gauss at point a at the beginning of the magnetic field,
It will be about 30 Gauss at point b).

By the way, if the glass tube 1 and the discharge path regulating body 8 are arranged in perfect concentric circles,
A discharge path can exist in any part of the cylindrical airtight space between the two with the same probability. However, when the above-mentioned magnetic field is applied, due to the difference in the magnetic flux density B between the upper and lower parts, the discharge impedance is equivalently large near the upper point a where the magnetic flux density B is relatively large; Near the lower point b where the density B is small, the discharge impedance also becomes small, and as a result, the discharge path H is pushed to the vicinity of the point b. At this time,
The phosphor coating 2b on the side of the discharge path H emits light. vice versa,
If the magnet 9 is moved to the point b side, light emission by the phosphor 2a can be obtained.

However, in the above conventional example, as is clear from the magnetic flux density distribution shown in FIG. Therefore, there were cases where the discharge path H was not formed at the desired position.

(Object of the Invention) The present invention has been made in view of the above points, and its object is to provide a low-pressure discharge lamp device that can more reliably form a discharge path at a desired position by the action of a magnetic field. .

(Disclosure of the Invention) The configuration and operating principle of the present invention are shown in FIG. In the conventional configuration shown in FIGS. 2 and 3, the present invention provides a magnetic material ( The other end side of the yoke 10 (for example, electromagnetic pure iron), that is, the side not connected to the magnet 9, is placed inside a cylindrical discharge path regulating body 8 with at least one end closed, and a glass plate is placed so as to face the magnet 9. It is characterized by being arranged along the axial direction of the tube 1. In addition, the fourth
The figure shows a case where the side of the magnet 9 connected to the yoke 10 is the south pole, so the yoke 10 is naturally also the south pole. In addition, in FIG. 4, an intermediate portion of the yoke 10 between the connecting portion with the magnet 9 and the discharge path regulating body 8 is omitted.

With this configuration, the portion of the yoke 10 along the discharge path regulating body 8 and facing the magnet 9 becomes the starting end or the ending end of the magnetic field, and forms a magnetic field between the yoke 10 and the magnet 9. In other words, the lines of magnetic force hardly leak anywhere else, and the magnetic lines are connected to the magnet 9 and the yoke 10.
It ends between.

Therefore, in this case, the distribution of magnetic flux density B between points a and b in the vertical direction of the cross section of the glass tube 1 is as shown in FIG.
Compared to the characteristic curve shown in Figure 3b above, the difference in magnetic flux density B near point a and point b becomes more significant, and the discharge path H is deflected more reliably. become.

Next, a specific embodiment of the present invention is shown in FIG. Since the configuration is substantially the same as the above-mentioned configuration, the explanation will be omitted by assigning the same reference numerals to the equivalent parts. Note that this embodiment is an example in which a yoke 10 is disposed inside the discharge path regulating body 8, and the magnet 9 and the yoke 1
In order to reduce the leakage magnetic field between the yoke 10 and
Among them, the portion 10a facing the magnet 9 is made larger in size than the remaining portion, increasing the area facing the magnet 9.

(Effects of the Invention) As described above, the present invention provides a yoke that corresponds to a magnet disposed outside the tube inside the discharge path regulating body disposed inside the tube, so that the magnetic field is concentrated in one place. Therefore, the difference in discharge impedance within the tube becomes clear. Therefore, the deflection of the discharge path becomes clearer, and for example, when the phosphor coated inside the tube is painted with different luminescent colors, the change in luminescent color can be made clear. Further, even when changing the light distribution characteristics, the desired light distribution characteristics can be achieved.

[Brief explanation of drawings]

1 and 2 show a conventional example, and in each figure, a is a partially cutaway front view, and b is a cross-sectional view. FIG. 3 is a diagram showing the operating principle of the conventional example shown in FIG. 2, FIG. 4 is a diagram showing the operating principle of the present invention, and FIG. 5 is a simplified diagram showing one embodiment of the present invention. DESCRIPTION OF SYMBOLS 1...Glass tube, 4...Electrode, 8...Discharge path regulator, 9...Magnet, 10...Yoke.

Claims (1)

[Scope of Claims] 1. A cylindrical discharge path regulating body with at least one end closed is placed in a glass tube of a straight tube type low-pressure discharge lamp having a pair of electrodes arranged at both ends, and the tube and the discharge path regulating body are connected to each other. They are arranged so as to form substantially concentric cylinders, and a magnet that generates a magnetic field in a direction substantially perpendicular to the tube axis is arranged outside the tube along the direction of the tube axis, and the discharge path is caused to form a concentric cylinder by the action of the magnetic field of the magnet. In a low pressure discharge lamp device formed at a desired position between the cylinders, the other end of the yoke, which is made of a magnetic material and one end of which is connected to the non-contact side pole of the magnet with the glass tube, is connected to the discharge path regulator. A low-pressure discharge lamp device, characterized in that the device is disposed inside along the tube axis direction so as to face the magnet. 2. The low-pressure discharge lamp device according to claim 1, wherein the width of the surface facing the magnet of the portion of the yoke along the discharge path regulator is made larger than that of the remaining portion of the yoke.