JP2005222910A - Discharge lamp lighting device and lighting fixture - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a reliable, small discharge lamp lighting device and lighting fixture in which a temperature rise due to a ripple and a deterioration of lifetime due to the operating temperature can be reduced and the self-temperature rise of capacitor can be reduced, and which has a long service life and high reliability. <P>SOLUTION: In a discharge lamp lighting device where a commercial or a direct current power source is input, the power source is converted to a high frequency, and the discharge lamp is lit at the high frequency; a film capacitor is provided in which a polypropylene film of not more than about 4μm in thickness is used as the capacitor, and an electric field applied to the film of the film capacitor is made to be about 85 V/μm or more. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a discharge lamp lighting device and a lighting fixture using a film capacitor.

Also in the conventional inverter device, as disclosed in Japanese Examined Patent Publication No. 7-75464, the capacitor used in the power supply smoothing portion of the electric equipment has a short life due to heat generation and temperature rise due to ripples. As an alternative, film capacitors using PET (polyethylene terephthalate) have been used. However, a capacitor using a polyethylene terephthalate film removes the defective portion by self-healing for the initial dielectric breakdown, but at the end of the capacitor life, it loses its capacity due to melting or short-circuiting due to heat generation due to dielectric breakdown or the like. There is a high possibility that the life of the apparatus may be shortened. In particular, the inverter type discharge lamp lighting device has a long use time and is used in various applications, and therefore, design considerations for extending the service life are necessary.
Japanese Patent Publication No. 7-75464

  In order to solve this problem, it is conceivable to use a PP (polypropylene) film in which the film shrinks greatly due to heat generation at the end of the life. PP (polypropylene) film capacitors have high shrinkage at temperatures exceeding 105 ° C to 125 ° C, so if there is heat generation due to dielectric breakdown of the capacitor or capacitor film, the film shrinks, the circuit is opened, and the capacitor is short-circuited. Can be prevented.

  However, when a polypropylene film capacitor is used, since the dielectric constant of the film is low, the shape of the capacitor tends to be large, resulting in a shape larger than that of an electrolytic capacitor. Recently, a thin film having a thickness of 4 μm or less has been developed. By using these, this problem can be solved.

  The present invention has been made in view of such a point, and by replacing an electrolytic capacitor or a polyethylene terephthalate film capacitor used in a circuit with a polypropylene film capacitor using a thin film having a thickness of about 4 μm or less, a ripple is obtained. It is possible to reduce the rise in temperature due to the temperature and deterioration of the lifetime due to the operating temperature, to reduce the self-temperature rise of the capacitor itself, to provide a long-life, reliable and safe, compact discharge lamp lighting device and lighting fixture To do.

  In the present invention, in order to solve the above-described problems, in a discharge lamp lighting device for inputting commercial or DC power, converting the power to high frequency, and lighting the discharge lamp at high frequency, the film has a thickness as a capacitor. A film capacitor using a polypropylene film of about 4 μm or less is provided, and an electric field applied to the film of the film capacitor is about 85 V / μm or more.

  According to the present invention, the electrolytic capacitor or polyethylene terephthalate capacitor used in the discharge lamp lighting device is replaced with a polypropylene film capacitor using a thin film having a thickness of 4 μm or less, so that the temperature rise due to the ripple and the life deterioration due to the use temperature can be reduced. It is possible to reduce the self-temperature rise of the capacitor itself, and it is possible to supply a small discharge lamp lighting device and lighting fixture that are long-life, reliable and safe.

(Embodiment 1)
FIG. 1 shows a main circuit diagram of a discharge lamp lighting device according to Embodiment 1 of the present invention. An AC input terminal of a rectifying diode bridge DB is connected to the commercial power source AC. A filter capacitor C1 is connected to the AC input terminal side of the rectifying diode bridge DB. This capacitor C1 is a film capacitor. A filter capacitor C2 is also connected to the DC output terminal side of the rectifying diode bridge DB. This capacitor C2 is also a film capacitor. One end of a chopper inductor L1 is connected to the positive electrode of the DC output terminal of the rectifier diode bridge DB. The other end of the chopper inductor L1 is connected to one end (drain side) of the chopper switching element S3 and to the anode side of the diode D1. The other end (source side) of the switching element S3 for chopper is connected to the negative electrode side (ground end) of the DC output terminal of the rectifying diode bridge DB. A smoothing electrolytic capacitor Ce and one end of a capacitor C3 are connected to the cathode side of the diode D1. The other ends of the smoothing electrolytic capacitor Ce and the capacitor C3 are grounded. The capacitor C3 is a capacitor that bypasses the high-frequency ripple component flowing in the electrolytic capacitor Ce, and a film capacitor is used. A series circuit of switching elements S1 and S2 is connected to both ends of the electrolytic capacitor Ce. One end of each filament of the discharge lamp FL is connected to both ends of the switching element S2 via a DC cut capacitor C4 and a current limiting and resonance inductor L2. A resonance capacitor C5 is connected in parallel to the other end (between the non-power supply side terminals) of the filaments of both electrodes of the discharge lamp FL. Both the DC cut capacitor C4 and the resonance capacitor C5 are film capacitors.

  The switching elements S1 and S2 are alternately turned on and off by the inverter controller 7. The switching element S3 is switched at a frequency sufficiently higher than the commercial frequency. By switching the switching element S3 at a high frequency, a smooth DC voltage is obtained at both ends of the electrolytic capacitor Ce. When the switching elements S1 and S2 are alternately turned on / off, the DC voltage of the electrolytic capacitor Ce is converted to a high frequency voltage, and the resonance circuit of the inductor L2 and the capacitor C5 is resonated at high frequency via the DC cut capacitor C4. The discharge lamp FL is turned on by the resonance voltage. In the circuit of FIG. 1, the capacitors C1 to C5 other than the electrolytic capacitor Ce can be constituted by film capacitors, but it goes without saying that the present invention can be applied if any one or more capacitors are film capacitors.

  Table 1 shows the rated voltage of the film capacitors C1 to C5 used in the circuit of FIG. 1, the type of film used as a dielectric, the thickness of the film (μm), the electric field applied to the film (film The potential applied to the unit thickness) is shown, and Table 2 shows the volume ratio when the conventional example of Table 1 is replaced with a polypropylene film capacitor having the same thickness as a comparative example. The dielectric constant εPP of the polypropylene film is generally εPP = 2.1, and the dielectric constant εPET of the polyethylene terephthalate film is generally εPET = 3.1, so that the dielectric constant ratio is 3.1 / 2.1, about The volume ratio is 1.5 times.

  Table 3 shows examples of the present invention, and shows the volume ratio when the conventional example in Table 1 is replaced with a polypropylene film capacitor of 4 μm or less. By setting the thickness of the polypropylene film to 4 μm or less, it can be contained in a volume ratio of 1.1 times or less with respect to the conventional example (Table 1) using the polyethylene terephthalate film capacitor.

  In this example, 4 μ to 3.5 μ polypropylene films were used, but by using these thinner films, polypropylene film capacitors smaller than conventional polyethylene terephthalate film capacitors can be used, and the discharge lamp lighting device is also small. And a long life. Further, the loss is about 1/10 of that of a polyethylene terephthalate film capacitor, and a discharge lamp lighting device with less heat generation can be realized.

(Embodiment 2)
2 and 3 show examples of the structure of the film capacitor. 2A is a perspective view showing an external appearance, and FIG. 2B is a perspective view showing an internal structure. FIG. 3 is a cross-sectional view showing the internal structure. The film capacitor 1 is constituted by winding two metallized films, spraying a metallicon 5 to form an electrode, and attaching a lead wire 2. The film 3 used is polypropylene and has high heat shrinkability. A capacitor is formed through the dielectric film 3 between the metallicon 5 and the vapor-deposited metal 4 opposite to the vapor-deposited metal 4 of the film 3. The resistance component of the capacitor is almost composed of the resistance of the lead wire 2 and the metallicon 5, the metallicon 5 and the film 3, and the deposited metal 4, and is expressed by tan δ as a substitute characteristic.

  FIG. 4A is a view showing the deposited metal 4 on the film 3, and the upper side in the figure is the electrode side. When a high electric field as described in the first embodiment is applied to the film and dielectric breakdown of the capacitor occurs, it may be repaired by self-healing, but when self-healing is difficult to occur, FIG. ), The deposited metal near the electrode side is scattered. This phenomenon tends to cause heat generation and a decrease in capacitor capacity due to an increase in tan δ.

  In order to solve such a problem, a vapor deposition film having a slit portion 6 as shown in FIG. In general, a capacitor using a vapor deposition film with such a slit portion 6 is called a capacitor with a security mechanism, and the vapor deposition metal is connected to the electrode portion on one side (the upper side in the figure). It is formed as if capacitors were connected in parallel. By adopting such a shape, even if dielectric breakdown occurs as shown by the black circle in FIG. 5B, only the cell having the dielectric breakdown part is separated as shown by the broken line. The voltage drop can be prevented. This film with a security mechanism may be single-sided or double-sided. The vapor deposition metal is generally abundant aluminum, but may be Zn or alloy.

  As for the film, the maximum operating temperature at the full rating of the conventional capacitor was 85 ° C. However, as disclosed in JP-A-10-156939 by Toray Industries, Inc. A heat-resistant polypropylene film and a capacitor using the same that can improve the maximum operating temperature compared to the prior art have been proposed, and Japanese Patent Application Laid-Open No. 10-119126 improved the maximum operating temperature by 20 ° C. A polypropylene film which can be made, and proposed as a metallized capacitor in Japanese Patent Application Laid-Open No. 5-217799. By using such a high heat-resistant polypropylene film, not only the operating temperature of the capacitor can be raised, but also dielectric breakdown can be reduced and the withstand voltage can be prevented from lowering.

(Embodiment 3)
In the present embodiment, in addition to the capacitors C1 to C5 used in the circuit of FIG. 1, the smoothing capacitor Ce is replaced with a polypropylene film capacitor. 2 or less.

  As shown in FIG. 4 of Japanese Patent Publication No. 7-75464, the life of the film capacitor is clearly longer than that of the electrolytic capacitor. In general, aluminum electrolytic capacitors employ the “Arrhenius Law”, which reduces the life by half when the ambient temperature rises by 10 ° C, and are designed to operate discharge lamp lighting devices and equipment even when the capacitor capacity is halved. Often. Table 4 shows the capacity tolerance and life of the film capacitor and the electrolytic capacitor.

  From this table, the electrolytic capacitor has a large capacity tolerance and a large capacity loss at the end of its life, so it is necessary to design the capacitor itself to be large. Moreover, since the shape is also circular, there is a problem that it is not suitable for thin mounting in recent years.

  Also for this problem, in the discharge lamp lighting device using the film capacitors C1 to C5 of the first or second embodiment, the smoothing capacitor Ce in FIG. A long-life discharge lamp lighting device suitable for thin mounting can be provided.

(Embodiment 4)
In this embodiment, the capacitor is coated with a resin material before being mounted on the substrate of the discharge lamp lighting device, and the film capacitor is inserted into a case of PBT, LCP or PPS, or an epoxy powder. It is characterized by being covered with a body material.

  In the example of FIG. 6, the capacitor element 1 is inserted into a resin case 8 of PBT (polybutylene terephthalate) or PPS (polyphenylene sulfide). In recent years, LCP (liquid crystal polymer) used for high heat resistance may be used. In the example of FIG. 7, the relatively small capacitor 1 is packaged with an epoxy-based powder resin 9 before being mounted on the substrate of the discharge lamp lighting device.

  The discharge lamp lighting device of Embodiments 1 to 4 can be used as a highly reliable lighting fixture by being incorporated in a lighting fixture in an office or a general home. In addition, a highly reliable lighting system can be constructed by combining a plurality of such lighting fixtures.

It is a circuit diagram which shows an example of the circuit structure of the discharge lamp lighting device of this invention. It is a perspective view which shows the external appearance and internal structure of a film capacitor. It is sectional drawing which shows the internal structure of a film capacitor. It is a top view which shows the vapor deposition film without a slit of a film capacitor. It is a top view which shows the vapor deposition film with a slit of a film capacitor. It is a perspective view which shows an example of the exterior structure of a film capacitor. It is a perspective view which shows another example of the exterior structure of a film capacitor.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Film capacitor 2 Lead wire 3 Dielectric film 4 Metal vapor deposition film 5 Metallicon 6 Slit 7 Inverter control part

Claims (6)

A discharge lamp lighting device for inputting commercial or DC power, converting the power to high frequency, and lighting a discharge lamp at high frequency, comprising a film capacitor using a polypropylene film having a film thickness of about 4 μm or less as a capacitor, A discharge lamp lighting device, wherein an electric field applied to a film of a capacitor is about 85 V / μm or more. In a discharge lamp lighting device having a chopper circuit, a polypropylene film having a film thickness of about 4 μm or less is used as a smoothing capacitor for the chopper circuit, and an electric field applied to the film is about 85 V / μm or more. A discharge lamp lighting device. 3. The discharge lamp lighting device according to claim 2, wherein the film capacitor has a capacity of about ½ or less of an electrolytic capacitor equivalent capacity. The discharge lamp lighting device according to any one of claims 1 to 3, wherein the film capacitor is inserted into a case of PBT, LCP, or PPS. The discharge lamp lighting device according to claim 1, wherein the film capacitor is covered with an epoxy powder material. A lighting fixture comprising a discharge lamp lighting device in which the capacitor according to any one of claims 1 to 5 is mounted.

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