JPH0527220B2 - - Google Patents

Description

[Detailed description of the invention]

INDUSTRIAL APPLICATION FIELD The present invention relates to a fluorescent lamp device. Conventional Structures and Their Problems Recently, various compact fluorescent lamp devices have been proposed as energy-saving light sources to replace incandescent light bulbs, and some have already been put into practical use. An example is shown in FIG. An arc tube 1, which is an elongated glass tube bent into a double U shape, is held inside an outer bulb globe 2. A white diffusing substance 3 is applied to the inner surface of the outer globe 2, and the inside of the outer globe 2 is in communication with the outside atmosphere. The lamp device includes a case 4 and a cap 5, and inside the case 4 is a ballast 6 for lighting the arc tube.
A glow starter 7 for starting is incorporated. As the stabilizer 6, a chiyoke coil is usually used. The configuration of the arc tube 1 used in such a compact fluorescent lamp device basically conforms to the specifications of a normal fluorescent lamp. The only difference is
This is in the method for regulating mercury vapor pressure during lighting. That is, the lamp efficiency of a fluorescent lamp reaches its maximum when the mercury vapor pressure at the time of lighting is around 6×10 ⁻³ Torr. and,
In ordinary fluorescent lamps, mercury is sealed in a single metal, and when the lamp is lit at room temperature, the coldest point temperature (specifying mercury vapor pressure) inside the tube is approximately 40°C, and the mercury vapor pressure is kept within the above-mentioned optimum range. It is designed to.
On the other hand, in compact fluorescent lamps, the arc tube is compact and lit under high load, and is further held inside the outer tube globe 2, so the coldest point temperature of the arc tube, that is, the mercury vapor pressure, is within the optimum range. The lamp efficiency is basically reduced by increasing the temperature more excessively.
Therefore, in order to commercialize such compact fluorescent lamps, it is necessary to regulate the mercury vapor pressure by some means, and various methods have been proposed to date. . FIG. 2 shows an arc tube 1' employing a typical amalgam filling method. Electrodes 8 and 9 are held at both ends of the double U-shaped arc tube 1' by lead wires 10 and 11 and stems 12 and 13, and a phosphor 1 is mounted on the inner surface of the arc tube 1'.
4 is attached. Furthermore, the interior of the arc tube 1' is filled with mercury and rare gases such as argon. Furthermore, in order to regulate the mercury vapor pressure, an amalgam-forming metallic substance 15 such as In, BiIn or BiPbSn is provided inside the capillary tube 16 at the rear of one of the stems, for example stem 12. During lighting, the metal substance 15 forms an amalgam with mercury. The mercury vapor pressure of this amalgam is lower than that of mercury alone, so even if the temperature at the coldest point rises to over 100℃,
Mercury vapor pressure can be maintained within the optimum range. The overall efficiency of the above-mentioned compact fluorescent lamp device is as high as approximately 40 lm/W, which is less than three times that of a light bulb, and the lamp is also convenient because it can be plugged into a light bulb socket and turned on. However, in order to develop such compact fluorescent lamps into one of the main sources of illumination, there are various problems that must be solved. The problem is that the fluorescent lamp device weighs approximately 400g, which is significantly heavier than a light bulb. This is because the weight of the chiyoke coil of the ballast 9 is about 250g, which is heavy.
The heavy weight of fluorescent lamp devices is one of the factors preventing their widespread use. To address these problems, a fluorescent lamp device has been proposed that incorporates a lightweight electronic ballast as a ballast instead of the conventional chiyoke coil. This reduces the weight of the entire device to about 1/2 compared to conventional ones.
However, another problem arises: the cost of the electronic ballast increases. OBJECTS OF THE INVENTION The present invention provides a lightweight and relatively low cost fluorescent lamp device. Structure of the Invention The inventor has conducted various studies on fluorescent lamp devices that meet the above objectives. As a result, it is possible to design a lamp at a lower cost by lighting it with an asymmetrical alternating current with a direct current component, rather than lighting with an alternating current without a direct current component, where the current per half cycle is symmetrical, as in conventional fluorescent lamps. We focused on one basic idea. By the way, in order to embody the above idea, a fluorescent lamp that can be lit with alternating current that has a direct current component is required. By the way, when a normal fluorescent lamp is turned on with alternating current that has a direct current component, a so-called cataphoresis phenomenon occurs, and as a result, mercury from the direct current component side moves toward one electrode, which acts as a cathode, and the electrode Only the positive column region near the electrode emits bright light, and the positive column region on the other electrode side becomes dark.
Therefore, as long as conventional fluorescent lamps are simply used, the above idea cannot be realized. As a next step, the inventor studied a lamp that would not cause the cataphoresis phenomenon even when lit with alternating current that has a direct current component. As a result, for the arc tube shown in Figure 2, an amalgam-forming substance was provided near one end of the arc tube, and the electrode on the side where the material was provided was used as an anode from the DC component surface of the arc tube. It has been discovered that if the lamp is lit, it is possible to suppress the occurrence of the above-mentioned cataphoresis phenomenon even if the lamp is lit with alternating current that has a direct current component. Based on this new knowledge, it became possible to light the lamp with alternating current with a direct current component, and a lightweight, relatively low-cost fluorescent lamp device was realized. DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments of the present invention will be described with reference to the drawings. The fluorescent lamp device first examined was basically based on the one shown in FIG. 1, and the amalgam-filled arc tube 1' shown in FIG. 2 was used as the arc tube. As shown in Figure 3, the lighting circuit uses a chopper type circuit that lights with alternating current with a direct current component. To explain the operation of such a circuit,
First, the rectifying bridge 17 and the smoothing capacitor 18 convert AC to DC. When starting the lamp, bidirectional 2-terminal thyristor (diac) 1
9 operates to turn on the power transistor 20, and the operation of the diode 21 and bidirectional two-terminal thyristor (SSS) 22 causes a preheating current to flow to the light bulb (not shown) of the arc tube 1'. Then,
The power transistor 20 is a light bulb detection transformer 23
is cut off by the feedback signal from the chain coil 24 and capacitor 2.
The arc tube 1' is lit by the voltage induced by the series resonant circuit with the arc tube 1'. After lighting, the chopper operation with a DC component is repeated by the functions of the power transistor 20, current detection transformer 23, choke coil 24, capacitor 25, and diode 26, and the arc tube 1' receives the voltage shown in FIG. 4. An asymmetrical discharge current flows. This discharge current waveform is indicated by number 27. Now, when lighting the arc tube 1' shown in FIG. 2 with the lighting circuit shown in FIG.
When lit as a cathode from the DC component perspective, it was observed that cataphoresis occurred. Such cataphoresis phenomenon became more pronounced as the ambient temperature became lower and the direct current component of the discharge electrode increased. Then, when the polarity of the electrodes is reversed and the electrode 8 on the end side of the arc tube provided with the metal material 15 for amalgam formation is turned on as an anode, the occurrence of the above-mentioned cataphoresis phenomenon is almost suppressed even in the constant temperature range (0 to 10 degrees Celsius). The light was completely suppressed, and a uniform light emission state was obtained over the entire area of the arc tube 1'. As a result of studying the mechanism of this new phenomenon, the inventor found that when cataphoresis occurs, mercury moves as ions from the anode (electrode 8) region to the cathode (electrode 9) region from the DC component surface. If the amalgam-forming metal substance 15 is present on the arc tube end side of the electrode 8 as the anode, the mercury vapor pressure inside the arc tube 1' will be higher on the electrode 8 side than on the electrode 9 side as the cathode. As a result, a diffusion phenomenon of mercury from the region of electrode 9 to the region of electrode 8 occurs due to this mercury vapor pressure difference. As a result, it is considered that the movement of mercury ions from the region of electrode 8 to the region of electrode 9 due to the occurrence of the above-mentioned cataphoresis phenomenon is offset by the movement of mercury due to the above-mentioned diffusion phenomenon in the opposite direction to this movement direction. As mentioned above, when the electrode 8 on the end side of the arc tube where the metal substance 15 is present is lit as a cathode from the DC component surface, the movement of mercury due to the occurrence of the cataphoresis phenomenon and the diffusion phenomenon both occurs at the electrode 9. Since this is carried out from the region to the region of the electrode 8, it can be said that the cataphoresis phenomenon is further promoted. Next, the specifications and various characteristics of a fluorescent lamp device that combines the amalgam-filled lamp according to the present invention and a circuit that lights with alternating current with a direct current component will be compared with a conventional fluorescent lamp device (shown in Figure 1). Shown in the table below.

[Table] As is clear from the above table, the weight of the device of the present invention has been reduced to approximately 1/2 compared to the conventional device, and the overall efficiency has also increased from the conventional 39 lm/W to approximately 50 lm/W. It has been obtained. Furthermore, the present invention is not applicable only to compact fluorescent lamp devices using bent fluorescent tubes, but can be applied to all types of fluorescent lamps, such as ordinary straight tube type and ring type fluorescent lamps. In the inventor's study, for example, regarding a straight-tube copying fluorescent lamp that is lit under high load, an amalgam-forming metal material is provided on either end of the arc tube, and the electrode on the side where this is provided is placed on the DC component surface. When lit with alternating current with a direct current component as an anode,
It has been confirmed that the occurrence of cataforesis phenomenon can be suppressed. Furthermore, in FIG. 2, the location where the metal substance 15 for forming the amalgam is provided does not necessarily need to be behind the electrode, but may be in the vicinity of the electrode that operates as an anode from the DC component side. Furthermore, as for the compact fluorescent lamp device related to FIG. 1, it is not necessarily necessary to integrate the arc tube section and the lighting circuit section, and the invention can also be implemented in a device in which the two are separated and held in, for example, a lighting fixture. The desired lightweight and relatively low-cost fluorescent lamp device can be realized. Effects of the Invention As explained above, the present invention provides an arc tube in which electrodes are provided at both ends of a glass tube, mercury and rare gas are sealed in the glass tube, and a phosphor is coated on the inner surface of the glass tube. An amalgam-forming substance is provided in the vicinity of one of the ends, and the electrode on the end side of the arc tube provided with the amalgam-forming substance is used as an anode from a direct current component surface, and the arc tube is connected to an alternating current having a direct current component. By turning on the fluorescent lamp, it is possible to suppress the occurrence of cathophoresis, and also to provide a fluorescent lamp device that can reduce weight and cost.

[Brief explanation of drawings]

FIG. 1 is a partially cutaway front view of a conventional compact fluorescent lamp device, FIG. 2 is a partially cutaway front view of a fluorescent lamp equipped with an amalgam-forming metal substance, and FIG.
The figure is a lighting circuit diagram of a fluorescent lamp device according to an embodiment of the present invention, and FIG. 4 is a discharge current waveform diagram at that time. 1'... Arc tube, 8, 9... Electrode, 15... Metallic substance, 17... Rectifier bridge, 18... Smoothing capacitor, 19... Bidirectional two-terminal thyristor,
20...Power transistor, 21...Diode, 22...Bidirectional two-terminal thyristor, 23...
Current detection transformer, 24...Chiyoke coil, 2
5...Capacitor, 26...Diode.

Claims (1)

[Claims] 1. An amalgam is formed near either end of an arc tube in which electrodes are provided at both ends of the glass tube, mercury and rare gas are sealed in the glass tube, and a phosphor is coated on the inner surface of the glass tube. A fluorescent lamp device characterized in that the arc tube is lit with alternating current having a direct current component, with the electrode on the end side of the arc tube provided with the amalgam forming material serving as an anode from a direct current component surface. .