JP2006092940A - Discharge lamp lighting device and lighting fixture - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a discharge lamp lighting device and a lighting fixture equipped with the same that will not cause unwanted problems, even if the filament of a discharge lamp is broken. <P>SOLUTION: The discharge lamp lighting device is provided with a discharge lamp DL equipped with filament electrodes E1, E2, an electronic lighting circuit INV biasing the discharge lamp and equipped with a protection movement function, a filament voltage regulating means FVS for regulating the voltage impressed between both terminals of one of the filament electrodes E1, E2, under the breakdown voltage of rare gas sealed in the discharge lamp DL and over a value exceeding the ionization potential of the rare gas. The filament voltage regulating means FVS is to clamp the voltages, impressed between the both terminals of the filament electrodes E1, E2 so as not to have voltages exceeding the breakdown voltage impressed, or is so structured not generate voltages over the breakdown voltage. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a discharge lamp lighting device for lighting a discharge lamp including a filament electrode and a lighting fixture including the discharge lamp lighting device.

  It is said that the scattered filament of the emitter at the end of the lamp life of a discharge lamp such as a fluorescent lamp is almost always broken. However, as the lamps become more narrow, the distance between the support rods supporting each filament is also shortened, so even if the lamp is disconnected, the disconnection may be connected by glow discharge depending on the degree of disconnection. Comes out. In this case, the detection means arranged for detecting the end of the lamp life described above and the detection means arranged for detecting the filament breakage cannot be detected. Moreover, if it is only connected by glow discharge, it will light like normal lighting, and there is no problem. However, when this state progresses in a bad state, the temperature of the base part rises in addition to the temperature rise of the lamp itself. In particular, in a compact lamp, since the base part is formed of a synthetic resin, the thermal deformation temperature is lower than that of the metal-worked base part.

  Therefore, when the filament breaks, glow discharge occurs between the breaks, and the sodium-containing support rod or glass stem emits orange sodium light, this is detected and the inverter circuit is protected. It has been proposed to try (see Patent Document 1).

  That is, in Patent Document 1, a discharge lamp having a filament and a support rod that supports the filament, a glass stem portion that fixes the support rod, and an inverter circuit that supplies high-frequency power to the discharge lamp, In a discharge lamp lighting device that contains sodium in the support rod or glass stem portion, after the filament breaks, a means for detecting that the sodium-containing support rod or glass stem portion has emitted orange sodium light is provided to emit sodium light. At the time of detection, a protection means is provided for stopping the oscillation of the inverter circuit or intermittently oscillating or reducing the output.

  Therefore, according to Patent Document 1, there is an advantage in that it is easy to detect filament breakage even in a thin tube discharge lamp.

In addition, in order to prevent a problem caused by glow discharge due to filament breakage, by restricting the voltage applied to the filament electrode to be equal to or lower than the ionization voltage of the discharge gas, even if filament breakage occurs, glow discharge does not occur. A proposal has also been proposed (see Patent Document 2).
JP 2001-185387 A JP 2002-203697 A

  However, the state where orange sodium luminescence is generated in the vicinity of the electrode of the discharge lamp is just before the abnormal state progresses and an emergency situation occurs such as melting of the glass stem part, smoking of the base part, or ignition, and at this stage the filament It is not always preferable to detect disconnection. Therefore, the means of Patent Document 1 has a problem.

  On the other hand, in the case of the means of Patent Document 2, in the case of argon that is generally enclosed in a fluorescent lamp, the ionization voltage is about 15 to 18 V, so that the preheating voltage applied to the filament electrode at the time of starting by the capacitor preheating circuit In order to obtain an accurate and highly reliable circuit operation, the circuit configuration becomes complicated, resulting in a cost increase.

  An object of the present invention is to provide a discharge lamp lighting device that does not cause an undesired problem even if a filament breakage of the discharge lamp occurs, and a lighting fixture including the discharge lamp lighting device.

  More specifically, the present invention relates to a discharge lamp lighting device and a discharge lamp lighting device configured so that even if a breakage occurs in the filament electrode, glow discharge does not occur in the breakage portion and the filament preheating at the start can be performed satisfactorily. A specific object is to provide a provided lighting fixture.

    A discharge lamp lighting device according to a first aspect of the present invention comprises: a discharge lamp having a filament electrode; an electronic lighting circuit for energizing the discharge lamp; and a maximum allowable voltage applied between both terminals of one filament electrode. Filament voltage regulating means for regulating the value to a value lower than the discharge start voltage of the rare gas sealed in the discharge lamp and exceeding the ionization voltage of the rare gas.

  In the present invention and each of the following inventions, the definitions and technical meanings of terms are as follows unless otherwise specified.

  [Discharge Lamp] The discharge lamp includes a filament electrode sealed therein, and a type that performs low-pressure discharge such as a fluorescent lamp is used. The filament electrode has at least a filament and an electron-emitting substance, but generally a pair of support pins is added to stretch the filament electrode.

  The pair of support pins are supported by connecting the both ends of the filament at their tip portions, and the base end portions stand apart from the stem portion of the valve. The base end of the support pin is connected to the external lead-in wire via a sealing metal such as a dumet wire that penetrates the stem portion in an airtight manner.

  The filament is composed of a double coil or triple coil made of refractory metal mainly composed of tungsten, and is disposed in the discharge space. The electron-emitting material is also referred to as an emitter, and is made of, for example, an alkali metal oxide and is attached to a filament. The electron radioactive material is gradually consumed as the life of the discharge lamp increases.

  When the discharge lamp is made of a fluorescent lamp, it generally includes members such as a translucent airtight container, a discharge medium, a phosphor layer, and a base in addition to the above-described configuration. The translucent airtight container is allowed to be set to various known shapes, tube diameters, lengths, and the like depending on the type of the discharge lamp and the rated power consumption. However, in a discharge lamp using a thin tube light-transmitting hermetic container such as a compact fluorescent lamp or a high-frequency lighting dedicated fluorescent lamp, the filament length is small, so the distance between the pair of support pins is also narrowed. The impact of this will be greater. Therefore, the present invention is effective for a discharge lamp using a thin tube light-transmitting hermetic container such as a compact fluorescent lamp or a high-frequency lighting dedicated fluorescent lamp.

  The discharge medium is generally made of a rare gas such as mercury and argon (Ar), but can be made of, for example, xenon only. Mercury can be encapsulated in the form of pure mercury or amalgam. The discharge medium emits ultraviolet light during discharge.

  The phosphor layer is formed on the inner surface side of the hermetic container of the discharge lamp, and is composed mainly of various known ultraviolet excitation type phosphors in order to perform desired light emission. When the discharge lamp is turned on and the discharge medium is discharged, ultraviolet light is emitted, and this ultraviolet light excites the phosphor in the phosphor layer, so that the phosphor layer emits desired light such as visible light and contributes to illumination. .

  The base is a member that functions to connect the discharge lamp to the lamp socket and to supply power from the lighting circuit or to support the lighting fixture in a predetermined position. Depending on the type, you can install the required type. For example, it is possible to adopt a single cap structure that is mounted on one end side of the discharge lamp, a double cap structure that is mounted on both ends of the discharge lamp, or the like.

  Moreover, as a material of the base body, not only plastics but also metal or the like can be constituted as desired.

  [Regarding Electronic Lighting Circuit] The electronic lighting circuit is a circuit means that is lit by applying a high-frequency AC voltage to the discharge lamp, and preferably includes an AC voltage generation circuit and a current limiting means. In the case of a discharge lamp such as a fluorescent lamp, luminous efficiency is improved by lighting at a high frequency of 10 kHz or more. Therefore, the frequency when the discharge lamp is turned on at a high frequency is preferably 10 kHz or more.

  The AC voltage generation circuit is a circuit means for converting a low-frequency AC such as a commercial AC power source into an AC voltage having a desired frequency, and can be configured mainly by a DC-AC conversion circuit such as an inverter. In this case, the DC-AC conversion circuit may have any configuration. For example, when generating a high frequency alternating current using a low frequency alternating current power source, the low frequency alternating current can be converted into a direct current and then converted into a high frequency alternating current. When converting into an alternating voltage using an inverter, the inverter may be of any circuit type. For example, a parallel inverter, a half bridge inverter, a one-stone inverter, or the like can be used. Further, the inverter may be either self-excited or separately excited.

  The current limiting means is means for limiting the lamp current to a predetermined value by interposing in series between the power source and the discharge lamp in order to stably light the discharge lamp, and is composed of an appropriate impedance, for example, an inductance. . When the inductance is used as the current limiting means, an inductor including a choke coil or a transformer can be used.

  In addition, the AC voltage generation circuit can be provided with a rectified DC power supply therein. Note that, regardless of whether the power source for the AC voltage generation circuit is AC or DC, a DC voltage conversion circuit unit such as a step-up chopper is provided as desired, and a DC input voltage for the AC voltage generation circuit such as an inverter is desired. The input voltage of the inverter can be changed for dimming.

  Further, the electronic lighting circuit is provided with circuit means for preheating the filament electrode when starting the discharge lamp. Since the filament electrode preheating circuit generally has a simple circuit configuration, a capacitor preheating circuit system is frequently used. In the present invention, since the filament voltage regulating means described later is provided, an electron having a circuit configuration capable of applying a voltage higher than the discharge start voltage of the rare gas sealed at the start, for example, during the operation of the discharge lamp. An integrated lighting circuit can be used. In the case of the capacitor preheating circuit system, since a voltage exceeding the discharge start voltage of the rare gas can be applied to the filament electrode at the time of starting, the capacitor preheating circuit system can be adopted according to the present invention. However, the present invention can also be applied to other electronic lighting circuits having a configuration in which a voltage exceeding the discharge start voltage of the rare gas can be applied to the filament electrode during operation of the discharge lamp.

  [Filament voltage regulating means] The filament voltage regulating means is configured such that the maximum allowable value of the voltage applied between both terminals of one filament electrode is lower than the discharge start voltage of the rare gas sealed in the discharge lamp, and It is a means to regulate the value exceeding the ionization voltage of the rare gas. That is, by clamping so that a voltage higher than the discharge start voltage is not applied between both terminals of one filament electrode, or by preventing the voltage higher than the discharge start voltage from being generated, the filament voltage regulating means Can be realized. However, in the present invention, a voltage having a value equal to or higher than the ionization voltage of the rare gas must be allowed to be applied. The former can be configured, for example, by connecting an appropriate clamp circuit in parallel with the filament electrode. The latter can be configured, for example, by monitoring the voltage of the filament electrode and performing feedback control of the AC voltage generation circuit so that the voltage does not exceed a predetermined value. The minimum value of the filament voltage should be determined according to design conditions for operating the discharge lamp DL, and may be equal to or lower than the ionization voltage of the rare gas.

  [Regarding the Action of the Present Invention] The discharge generated when the filament breaks during operation of the discharge lamp is a glow discharge of a rare gas such as argon (Ar) enclosed in the discharge lamp. When the rare gas is argon, the discharge start voltage of the glow discharge is between about 100 to 200 V, although it varies depending on various conditions. Once the discharge is started, the discharge is maintained at a voltage of about 15 to 18V.

  In the present invention, the maximum allowable value of the voltage applied between both terminals of one filament electrode is regulated to a value higher than the ionization voltage of the rare gas and lower than the discharge start voltage. Even if the wire breaks, since the filament voltage is low and the discharge does not start, glow discharge cannot occur. Accordingly, overheating of the vicinity of the filament due to glow discharge or stem melting caused by the progress thereof can be prevented. However, since it is possible to apply a voltage having a value exceeding the ionization voltage of the rare gas, it is possible to apply an optimum voltage to the filament electrode during heating of the filament at the start, giving good start characteristics. can do.

    A lighting fixture according to a second aspect of the present invention includes: a lighting fixture main body; and the discharge lamp lighting device according to the first aspect disposed in the lighting fixture main body.

  In the present invention, the use and structure of the lighting fixture are not limited. However, the present invention is particularly effective in a domestic lighting apparatus configured to be able to perform thinning lighting. The luminaire main body means the remaining part of the luminaire excluding the discharge lamp lighting device. The discharge lamp lighting device may not only be partly or entirely mounted on the luminaire main body, but may be disposed apart from the luminaire main body.

  According to the first aspect of the present invention, the maximum allowable value of the voltage applied between the pair of terminals of one filament electrode is lower than the discharge start voltage of the rare gas enclosed in the discharge lamp, and the ionization of the rare gas is performed. Even if filament breakage occurs due to the regulation of the voltage exceeding the voltage, glow discharge cannot occur between both terminals of one filament electrode, so the vicinity of the filament due to glow discharge and stem melting caused by its progress While preventing overheating of the part, a starting voltage having a required value can be applied to the filament electrode at the time of starting, so that a discharge lamp lighting device having good starting characteristics can be provided.

  According to invention of Claim 2, the lighting fixture which has the effect of Claim 1 can be provided.

  Embodiments of the present invention will be described below with reference to the drawings.

    FIG. 1 is a circuit diagram showing a first embodiment for carrying out the discharge lamp lighting device of the present invention. In the figure, AC is a low-frequency AC power supply, EOC is an electronic lighting circuit, DL is a discharge lamp, and FVS is a filament voltage regulating means.

  The low frequency AC power source AC is composed of, for example, a commercial AC power source.

  The electronic lighting circuit EOC includes an AC voltage generation circuit INV and a load circuit LC. The AC voltage generation circuit INV mainly includes a noise filter NF, a rectified DC power supply RDC, and an inverter main body HBI.

  The noise filter NF is interposed between the low frequency AC power source AC and the rectified DC power source RDC and prevents high frequency noise from flowing out to the low frequency AC power source side.

  The rectified DC power supply RDC includes a full-wave rectifier circuit FBR and a smoothing capacitor C1, and rectifies a low-frequency AC voltage to obtain a smoothed DC voltage.

  The inverter main body HBI is a half-bridge inverter, and includes a pair of switching elements Q1 and Q2 connected in series to the rectified DC power supply RDC and a drive circuit DC thereof. The pair of switching elements Q1 and Q2 constitutes a series circuit, and both ends thereof are connected between both electrodes of the rectified DC power supply RDC. A rectangular wave high-frequency AC output is obtained between both ends of the switching element Q2.

  The load circuit LC is composed of a series circuit of a DC cut capacitor C2, a current limiting inductor L1 and a capacitor C3, and both ends thereof are connected between output terminals of the AC voltage generation circuit INV. Current limiting inductor L1 and capacitor C3 form a series resonant circuit.

  The discharge lamp DL is a fluorescent lamp and includes a pair of filament electrodes E1 and E2. The pair of filament electrodes E1 and E2 are inserted in series into the load circuit LC at both ends of the capacitor C3, whereby the discharge lamp DL is connected in parallel to the capacitor C3. Therefore, the capacitor C3 forms a capacitor preheating circuit.

  The filament voltage regulating means FVS is formed, for example, by connecting a required number of Zener diodes in reverse series, and connecting them in parallel to the filament electrodes E1 and E2, respectively. And the clamp voltage of the filament voltage regulating means FVS, in other words, the Zener voltage is lower than the discharge start voltage of the rare gas sealed in the discharge lamp DL, and the voltage applied between both terminals of one filament electrode is And it is set to a value exceeding the ionization voltage.

  Next, circuit operation will be described. That is, when the high frequency voltage output from the electronic lighting circuit is applied to the load circuit LC, the terminal voltage of the capacitor C3 rises due to the series resonance of the inductor L1 and the capacitor C3, so that both ends of the filament electrodes E1 and E2 Since the filament voltage regulating means FVS clamps to the clamp voltage even if the voltage applied to the electrode exceeds the ionization voltage of the rare gas and exceeds the discharge start voltage of the rare gas, the filament electrodes E1, E2 A voltage regulated to a voltage equal to or less than the leakage clamp voltage is applied between the two terminals.

  Therefore, even if a filament breakage occurs in any of the filament electrodes, only a voltage equal to or lower than the discharge start voltage is applied to the filament electrode, so that glow discharge does not occur.

  Further, since the voltage applied between both terminals of one filament electrode at the time of filament preheating at start-up can be set higher than the ionization voltage of the rare gas, optimum filament preheating can be performed. Therefore, the discharge lamp DL can be started as desired.

    FIG. 2 is a circuit diagram showing a second embodiment for carrying out the discharge lamp lighting device of the present invention. In the figure, the same parts as those in FIG. In this embodiment, the filament voltage regulating means FVS is composed of an overvoltage monitoring circuit, and its output end is configured to control and input to the AC voltage generating circuit INV.

  Thus, when the filament voltage regulating means FVS monitors the voltage applied between the two terminals of the filament electrodes E1 and E2, and detects an overvoltage higher than the discharge start voltage, it controls the high frequency generation circuit INV. Then, the output voltage of the high-frequency generation circuit INV is controlled so that the voltage applied between both terminals of one filament electrode E1 or E2 is equal to or lower than the discharge start voltage. As a result, no glow discharge occurs in the filament electrodes E1 and E2. The electronic lighting circuit EOC and the load circuit LC are configured such that a voltage equal to or higher than the ionization voltage of the rare gas is applied to the application filament electrodes E1 and E2 at the time of starting.

    FIG. 3 is a circuit diagram showing a third mode for carrying out the discharge lamp lighting device of the present invention. In the figure, the same parts as those in FIG. This embodiment shows another configuration in the filament voltage regulating means FVS of the type that clamps the voltage applied to both ends of the filament electrodes E1 and E2.

  That is, the filament voltage regulating means FVS connects both ends of a series connection circuit of a plurality of resistors R1, R2, R3, R4 between output ends of the AC voltage generation circuit INV, and both ends of the resistor R2 to the filament electrode E1. The resistors R4 are connected in parallel, and both ends of the resistor R4 are connected in parallel to the filament electrode E2.

  Thus, the output voltage of the AC voltage generation circuit INV is divided by a series connection circuit of a plurality of resistors R1, R2, R3, R4 constituting the filament voltage regulating means FVS. Therefore, the voltage applied to both ends of the filament electrode E1 is clamped to a divided voltage obtained across the resistor R2. Similarly, the voltage applied to both ends of the filament electrode E2 is clamped to a divided voltage obtained across the resistor R4. Therefore, the resistance values of the resistors R2 and R4 are applied between both terminals of the filament electrodes E1 and E2 by appropriately setting the voltage dividing ratio with the resistors R1 and R3 and the output voltage of the AC voltage generation circuit INV. The maximum allowable value of the voltage can be regulated to a value that is equal to or lower than the discharge start voltage and exceeds the ionization voltage of the rare gas.

    FIG. 4 is a conceptual cross-sectional view showing a domestic ceiling-mounted lighting fixture as an embodiment for implementing the lighting fixture of the present invention. In the figure, 11 is a chassis, 12 is a reflector, 13A and 13B are annular fluorescent lamps, 14 is a shade, 15 is an electronic lighting circuit, and 16 is a hooking ceiling adapter.

The chassis 11 is formed by press-molding a metal plate, a through hole is formed at the center, and a standing edge 11a (in the drawing, facing downward) is formed at the periphery.

  The reflector 12 is formed by molding a white synthetic resin and is disposed on the lower surface of the chassis 11.

  The annular fluorescent lamp 13A has a tube diameter of 16.5 mm, an outer ring diameter of 373 mm, an inner ring diameter of 340 mm, and a rated lamp power of 34 W / 48 W. The annular fluorescent lamp 13B has a tube diameter of 16.5 mm, an annular outer diameter of 225 mm, an annular inner diameter of 192 mm, and a rated lamp power of 20 W / 28 W. These annular fluorescent lamps 13A and 13B are configured to be attached to and detached from a predetermined place of the reflector integrally by a single lamp holder (not shown), and at the same time, required connection to the electronic lighting circuit 15 is performed. ing.

The shade 14 is formed of milky acrylic resin or the like in a thin dome shape to cover the chassis 11, the reflector 12, the annular fluorescent lamps 13 </ b> A and 13 </ b> B, and the opening edge 14 a is fitted inside the standing edge 11 a of the chassis 11 It is detachably fixed in the state.
The electronic lighting circuit 15 is a circuit configuration in which the discharge lamp lighting device of the present invention is implemented, and is energized by lighting the annular fluorescent lamps 13A and 13B, and is a space formed between the chassis 11 and the reflector 12 It is arranged in the inside. Although the electronic lighting circuit 15 appears to be divided into two in the figure, it has an integrated configuration.

  The hook ceiling adapter 16 receives AC power from the ceiling and supplies electric energy to the ceiling light, and functions to attach the ceiling light to the ceiling. The hooking sealing cap mechanism 16a and an electrical connector and a hooking claw, which are not shown, are provided.

  The hooking sealing cap mechanism 16a is electrically and mechanically connected to the hooking sealing body by being detachably hooked to an embedded or exposed hooking sealing body (not shown) disposed on the ceiling. Is done.

  The electrical connector is connected to the hooking ceiling cap mechanism via an insulated wire, and is connected to a power receiving plug disposed on the reflecting plate 12, thereby forming a power feeding path to the ceiling light.

  The hooking claw protrudes from the side surface of the hooking ceiling adapter 16 so as to be able to advance and retreat, and is locked in a locking hole that opens on the side surface of the cylindrical hole 12a formed in the center of the reflecting plate 12.

The circuit diagram which shows the 1st form for implementing the discharge lamp lighting device of this invention The circuit diagram which shows the 2nd form for implementing the discharge lamp lighting device of this invention The circuit diagram which shows the 3rd form for implementing the discharge lamp lighting device of this invention 1 is a conceptual cross-sectional view showing a household ceiling-mounted lighting fixture as one embodiment for implementing the lighting fixture of the present invention.

Explanation of symbols

  DL: Discharge lamp, EOC: Electronic lighting circuit, FBR: Full wave rectifier circuit, FVS: Filament voltage regulating means, HBI: Inverter body, INV: High frequency generator circuit, LC: Load circuit, NF ... Noise filter, RDC ... Rectifier DC power supply

Claims (2)

A discharge lamp with a filament electrode;
An electronic lighting circuit for energizing the discharge lamp;
Filament that regulates the maximum allowable value of the voltage applied between both terminals of one filament electrode to a value that is lower than the discharge start voltage of the rare gas sealed in the discharge lamp and exceeds the ionization voltage of the rare gas. Voltage regulation means;
A discharge lamp lighting device comprising: A lighting fixture body;
A discharge lamp lighting device according to claim 1, which is disposed in a lighting fixture body;
The lighting fixture characterized by comprising.

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