JP2006237013A - Compact self-ballasted fluorescent lamp and luminaire - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a compact self-ballasted fluorescent lamp and a luminaire equipped with a small-sized arc tube. <P>SOLUTION: The compact self-ballasted fluorescent lamp 10 has two first U-shaped bent bulbs 31 composed of a bent part 31a with the top part formed in a curving shape and a pair of linear parts 31b continuing from the bent part 31a, and two second U-shaped bent bulbs 31' with the bent curvature and height dimension of the top part smaller than the first U-shaped bent bulb 31. The first and the second U-shaped bent bulbs 31 and 31' overlap each other in a state of each of the planes being parallel to each other and the two first U-shaped bent bulbs 31 are equipped with the arc tube 18 which is arranged in between the two first U-shaped bent bulbs 31 and sandwiched, and which has a discharge passage inside the part where the adjacent first U-shaped bent bulb 31 and the second U-shaped bent bulb 31' are juxtaposed so as to overlap, and thereby, the arc tube can be made small in size. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a light bulb shaped fluorescent lamp and a lighting fixture.

  Conventionally, for example, a bulb-type fluorescent lamp having a cover having a base that can be attached to a socket of a general lighting bulb, storing a lighting circuit inside the cover, and bending the arc tube into a globe is known. It has been.

  In recent years, fluorescent lamps, which are arc tubes, have become smaller and more efficient due to the use of electronic circuits in lighting circuits, processing technology, material improvements, etc., and such bulb-type fluorescent lamps have been developed and implemented (for example, patent documents). 1).

  This bulb-type fluorescent lamp is characterized by having an equivalent light output, high efficiency, and long life while having a size equivalent to an incandescent bulb 60W.

  The bulb-type fluorescent lamp currently on the market is an alternative to incandescent bulbs centering on the 60W type, and the height including the base is about 125 mm and the outer diameter is about 60 mm.

In addition, the E26 type standardized by JIS (C 7709), which is used for incandescent bulbs centering on 60 W, is also used.
JP 2000-21351 A

  With the advent of the above-mentioned conventional bulb-type fluorescent lamp, almost all incandescent bulbs attached to existing general lighting fixtures can be replaced with high-efficiency bulb-type fluorescent lamps, greatly contributing to an energy-saving society. Yes.

  However, since the above-mentioned conventional bulb-type fluorescent lamp is larger than the small incandescent bulb and has a different cap size, the bulb-type fluorescent bulb has a compact arc tube that can be replaced with a lighting fixture dedicated to the small incandescent bulb. A fluorescent lamp has not been realized.

  This invention is made | formed in view of such a point, and it aims at providing the light bulb-type fluorescent lamp provided with the miniaturized arc tube, and a lighting fixture.

  The bulb-type fluorescent lamp according to claim 1 is provided with two first U-shaped bent bulbs having a bent portion with a curved top portion and a pair of straight portions continuing to the bent portion, and a bent curvature and high height of the top portion. It has two second U-shaped bent valves having a smaller dimension than the first U-shaped bent valve, and the first and second U-shaped bent valves have planes formed by each other. The two first U-shaped bent valves that are overlapped in parallel are sandwiched between the first U-shaped bent valves that are disposed in the middle and located on both sides, and the first and second The line connecting the tops of the U-shaped bent valves is straight, and the top of the second U-shaped bent valve is positioned closer to the straight section than the top of the first U-shaped bent valve. A portion of the adjacent first U-shaped bent valve and second U-shaped bent valve are An arc tube arranged side by side so as to form a single discharge path; a cover to which the arc tube is attached and having a base, to which the arc tube is attached; And a lighting circuit to be accommodated.

  In the present claims and the following claims, the definitions of terms are as follows.

  In the arc tube, at least one discharge path is formed inside by arranging the first and second U-shaped bent bulbs so as to communicate with each other. An electrode for causing discharge in the discharge path is sealed.

  The first and second U-shaped bent valves are preferably made of glass such as lead glass, soda lime glass, and borosilicate glass. However, other materials such as ceramics may be used as long as they are translucent. . In particular, it is optimal to use lead-free glass in consideration of environmental impact.

Lead-free glass is glass that does not substantially contain lead, and may contain lead of an impurity level. For example, Na ₂ O is 0 to 10 mass%, K ₂ O is 1 to 10 mass%, LiO is 0 to 3 mass% (however, the total amount of Na ₂ O, K ₂ O and Li ₂ O is 5 to 20 And a glass having a softening temperature of 685 ° C. or lower. Glass using K ₂ O and Li ₂ O together with Na ₂ O as a flux has a composition that does not substantially contain lead, and can lower the softening temperature to 685 ° C. or lower compared to conventional soda-lime glass. . By applying such a glass with a low softening point to a glass bulb, the heating temperature at the time of bulb processing can be reduced. Based on this reduction in the heating temperature, the phosphor layer is thermally deteriorated, and thus the total luminous flux is reduced. Can be suppressed. Furthermore, by setting the amount of Na ₂ O to 10% by mass or less, it is possible to suppress the coloring caused by the Na component in the glass, and hence the decrease in the luminous flux maintenance factor.

  The first and second U-shaped bent bulbs have a shape having a bent portion for bending the discharge path in a substantially U-shape at the intermediate portion. The bent portion may be formed by bending by softening the glass bulb, or by forming by molding or a connecting pipe. Further, the shape of the bent portion may be formed in a substantially U-shape having right-angle portions at both corners of a flat top portion by molding or the like in addition to those bent in a semicircular arc shape. .

  A phosphor layer is applied directly or indirectly to the inner surface of the U-shaped bent bulb, and an inert gas such as argon, neon, or krypton and a discharge medium such as mercury are sealed inside. As the phosphor, a three-wavelength emission type rare earth metal oxide phosphor, a calcium halophosphate phosphor, or the like can be used.

  The cover supports the fluorescent lamp directly or indirectly. As a means for indirectly supporting, it is preferable to attach a holder having a shape in which both ends of the arc tube can be inserted in a portion opposite to the direction in which the cover base is attached.

  As the base, a screw-in type called E-type is usually used. Further, the base need not be directly attached to the cover, but may be indirectly attached to the case or a part of the cover may constitute the base.

  The lighting circuit is housed in the cover and is preferably an inverter type, but is not limited to this because of the nature of the present invention. The lighting circuit is housed by being directly or indirectly attached to the cover.

  According to a second aspect of the present invention, there is provided a lighting fixture comprising: a fixture main body; and the light bulb shaped fluorescent lamp according to the first aspect which is mounted on the fixture main body.

  According to the bulb-type fluorescent lamp of claim 1, the arc tube is configured by arranging the first U-shaped bent bulb and the second U-shaped bent bulb adjacent to each other so as to overlap each other. Therefore, the arc tube can be miniaturized, and a light bulb-type fluorescent lamp that can be attached to a lighting fixture to which a small incandescent light bulb is attached can be provided.

  According to the luminaire of claim 2, it is possible to provide a luminaire in which a small incandescent bulb is replaced with a bulb-type fluorescent lamp.

  An arc tube used for a bulb-type fluorescent lamp has two first U-shaped bent bulbs having a bent portion with a curved top portion and a pair of straight portions continuing to the bent portion, and a bent curvature of the top portion. And two second U-shaped bent valves having a height dimension smaller than that of the first U-shaped bent valve.

  The arc tube has two first U-shaped bent bulbs and two second U-shaped bent bulbs arranged in parallel so that at least one discharge path is formed inside. An electrode for causing discharge in the discharge path is sealed at the end of the arc tube.

  Examples of the electrode include a hot cathode made of a filament, a ceramic electrode carrying an electron emitting material, and a cold cathode made of nickel. The tubular bulb may be one utilizing a rare gas discharge that does not enclose mercury or having an electrode outside.

  The first and second U-shaped bent valves are respectively arranged in the overlapping direction in a state where the planes formed by them are parallel to each other. The two first U-shaped bent valves are arranged in the middle, and the first U-shaped bent valves are respectively positioned on both sides of the two first U-shaped bent valves. The valve is disposed so as to be sandwiched between the first U-shaped bent valve. The lines connecting the tops of the first and second U-shaped bent valves are arranged to form a straight line. Furthermore, the top of the second U-shaped bent valve is positioned on the straight line side of the top of the first U-shaped bent valve, and the adjacent first U-shaped bent valve and the second U-shaped bent valve The U-shaped bent valves are juxtaposed so as to partially overlap each other.

  When using a U-shaped bent valve with a narrow tube whose inner diameter is 8 mm or less, it is difficult to dispose the filament electrode in a direction perpendicular to the valve axis. The small electrode used may be used. This electrode is formed by supporting a granular ceramic having an average particle size of 0.1 to 10 μm on a lead wire directly or by an electrically conductive container, and is smaller in size than a filament electrode. The disassembling process is unnecessary. A light-emitting tube equipped with a high-illuminance lamp-shaped electrode that does not restrict the lamp current like a cold cathode even if it is a U-shaped bent bulb of a thin tube by using a small electrode using granular ceramics It can be. The material for the container for supporting the granular ceramics is not particularly limited as long as it has this conductivity. However, it is preferable to use a transition metal alone such as Ta or a conductive material mainly composed of an alkaline earth element and a transition metal element. The one made of ceramics is good.

Here, the granular ceramic used for the small electrode will be described in detail. Granular ceramics as thermionic emission materials are composed of oxide composite ceramics mainly composed of alkaline earth elements and transition metal elements. Preferably, one or more kinds selected from the group consisting of BaO, CaO and SrO are used as the alkaline earth element oxide. Further, any one or more of ZrO ₂ and TiO ₂ as transition metal elements, V ₂ O ₅ , Nb ₂ O ₅ , Ta ₂ O ₅ , Sc ₂ O ₃ , Y ₂ O ₃ , La ₂ O ₃ , Dy ₂ O ₃ , Ho ₂ O ₃ , HfO ₃ , CrO ₃ , MoO ₅ , and WO ₃ are used. The granular ceramics may be formed in the form of granules, sponges or lumps. Further, the surface of the granular ceramic may be coated with carbide and / or nitride in order to prevent sputtering.

  Mercury is enclosed in the arc tube, but it is preferably enclosed as amalgam. The amalgam may have either a property of having a vapor pressure higher than that of pure mercury sealed for efficient lighting even at a high temperature, or a material for quantitatively sealing mercury in the bulb. In particular, since the arc tube becomes hot when the lamp is lit, an amalgam having a vapor pressure characteristic corresponding to the lighting temperature should be selected. Examples of amalgam in consideration of vapor pressure characteristics include bismuth (Bi) -indium (In) -mercury (Hg), bismuth (Bi) -tin (Sn) -lead (Pb) -mercury (Hg), bismuth (Bi). ) -Indium (In) -lead (Pb) -mercury (Hg), but not limited thereto. Examples of the amalgam for quantitative encapsulation include, but are not limited to, zinc (Zn) -mercury (Hg). Moreover, although it is not an amalgam, you may hold | maintain the pellet-shaped thing which carried mercury on substances, such as ceramics, in a thin tube.

  It is preferable that the arc tube has a first and second U-shaped bent bulbs arranged in parallel to have a discharge path length of 120 to 200 mm and a maximum width of 45 mm or less. Experiments have confirmed that the discharge path length is required to be 120 mm or more in order to obtain a light output substantially equivalent to that of a small incandescent bulb. That is, if the discharge path length is less than 120 mm, a desired light output cannot be obtained, and the ratio of the electrode loss portion that does not contribute to light emission to the discharge path length increases, so that the desired lamp efficiency cannot be obtained. . Therefore, the discharge path length needs to be 120 mm or more. However, if the discharge path length exceeds 200 mm, the lamp starting voltage becomes excessively high, and it is difficult to generate a sufficient starting voltage in a small inverter circuit accommodated in the external dimensions substantially the same as a small incandescent bulb. Therefore, the discharge path length was 120 to 200 mm. In order to accommodate the arc tube within the outer dimensions substantially the same as those of the small incandescent bulb, the arc tube must have a maximum width of 45 mm or less and the height is limited to 55 mm or less. Under these conditions, in order to obtain a bulb having a discharge path length of 120 to 200 mm, a lighting test was performed with various bulbs having different tube diameters. As a result, a U-shape with a tube inner diameter of 5 to 9 mm and a height of 35 to 55 mm was obtained. Experiments have confirmed that a sufficient luminous output and lamp efficiency can be obtained by constructing an arc tube by combining a bent-shaped bulb. The arc tube has a tube inner diameter limited to 9 mm or less in order to make the discharge path length 120 mm or longer, but by setting the tube inner diameter to 9 mm or less, the lamp current is suppressed as much as possible to increase the lamp voltage, and the lighting circuit efficiency. It became possible to raise. That is, as the lamp current increases, the heat loss in the lighting circuit increases, and this tendency becomes more prominent as the power consumption decreases. Therefore, in an arc tube having a lamp power of 12 W or less, the discharge path length is 120 to 200 mm, and the tube inner diameter is It is desirable to make it 9 mm or less. If the inner diameter of the tube is less than 5 mm, the starting voltage increases, the lamp efficiency decreases, and the arc tube manufacturing becomes complicated. Therefore, the U-shaped bent valve has a tube inner diameter of 5 to 9 mm and a maximum height of 35 to 55 mm. Considering the manufacturing process and arc tube efficiency, the maximum height of the U-shaped bent bulb may be preferably 40 to 55 mm. However, if the manufacturing process and arc tube efficiency are not affected, the height is set to 35. It is desirable to be within a range of ˜55 mm. Thus, the arc tube is lit with a lamp power (power input between the electrodes of the arc tube) of 7 to 12 W, taking into consideration the discharge path length, the inner diameter of the tube, the phosphor layer, the gas type, the gas pressure, etc. In addition, the total luminous flux is 450 lm or more, and the lamp efficiency is 45 lm / W or more, more preferably 50 lm / W or more. By using a bulb-type fluorescent lamp having an arc tube configured in this way, it is possible to obtain a light source of substantially the same size with a light output equivalent to that of a small incandescent bulb.

  The cover is configured so that the arc tube is attached and has a base, and the overall height of the bulb-type fluorescent lamp is 75 to 105 mm including the base. In addition, the globe which covers a fluorescent lamp may be attached to the cover. The globe may be either light diffusive or transparent as long as it has light transparency, and may be patterned or colored. The material of the globe may be glass or plastic. The shape of the globe is arbitrary, but the so-called A-shaped shape that is similar to the incandescent light bulb, which is commonly used, the so-called G-shape that is similar to a sphere, the so-called T-shape that is a spherical tip, and a cylindrical shape A so-called shape or the like can be employed. The height of the bulb-type fluorescent lamp when the globe is attached is defined as the height including the globe.

  The lighting circuit is composed of a small inverter circuit, but it is necessary to use a smaller electronic component mounted on the inverter circuit in order to accommodate the external dimensions approximately the same as a small incandescent bulb. There is. In particular, an inductance element used as a current limiting impedance element is a component having a relatively large volume, such as a ferrite core and a bobbin, and downsizing the inductance element is a point of downsizing the inverter circuit.

  The inductance element can be used because the effective cross-sectional area (Ae) and bobbin window area (Aw) of the ferrite core are determined from the lamp current, lighting frequency, current-limiting inductance, coil magnetic flux density, winding current density, etc. The type of inductance element is determined. If the effective cross-sectional area (Ae) and the bobbin window area (Aw) of the ferrite core are large, the size of the inductance element is increased accordingly. The value obtained from the effective cross-sectional area (Ae) and the bobbin window area (Aw) of the ferrite core is proportional to the inductance (L) value when the lamp current and the like are constant, and the inductance is generally increased when the lighting frequency is increased. Since the (L) value is also reduced, the size of the usable inductance element can be reduced as the lighting frequency is increased.

  In the conventional bulb-type fluorescent lamp, the lighting circuit is designed to light up at a high frequency of several tens of kHz, and the EE13 type is used as the inductance element used as the current limiting impedance element. In order to reduce the size of this inductance element, the lighting frequency that can be used with the EI12.5 type inductance element that is slightly smaller than the EE13 type was examined by experiment, and it was confirmed that the lighting frequency should be 100 kHz or more. It was. Needless to say, by setting the lighting frequency to 100 kHz or more, an inductance element having a shape equal to or smaller than that of the EI 12.5 type can be used.

  In addition, power supply noise (noise terminal voltage) generated by electronic equipment is standardized in the range of 526.5 kHz to 30 MHz. If the lighting frequency of the inverter circuit exceeds 175 kHz, the third harmonic component is generated. Occurs within the above standard. Therefore, a special noise prevention filter is required and is not suitable for downsizing, so the lighting frequency needs to be 175 kHz or less.

  In addition, although the lighting frequency of an inverter circuit needs to be 100-175 kHz, when the dispersion | variation in an inductance element, a lamp current value, etc. is considered, it is preferable to make a lighting frequency into the range of 120-150 kHz.

  Hereinafter, an embodiment of a light bulb shaped fluorescent lamp and a lighting fixture of the present invention will be described with reference to the drawings.

  FIG. 1 and FIG. 2 show a first embodiment, FIG. 1 is a side view of a bulb-type fluorescent lamp, and FIG. 2 is a schematic top view partially showing an arc tube portion of the bulb-type fluorescent lamp. Note that FIG. 2 is shown in a state where the globe is seen through in a relationship that simplifies the description.

  1 and 2, reference numeral 10 denotes a bulb-type fluorescent lamp. The bulb-type fluorescent lamp 10 includes a cover 14 having a base 12, a lighting circuit 16 accommodated in the cover 14, and a light-transmitting globe 17. And an arc tube 18 housed in the globe 17. The envelope composed of the globe 17 and the cover 14 is formed in an outer shape approximating the standard size of a 75W-shaped general lighting small incandescent bulb (mini-krypton bulb, rated power consumption 71 W).

  The cover 14 is formed of a heat-resistant synthetic resin such as polybutylene terephthalate (PBT), has a substantially cylindrical shape that expands downward, and is covered with an E17-shaped base 12 at the upper end portion. Or it is fixed by caulking.

  The globe 17 is transparent or light diffusing milky white or the like, and is formed of a glass or a synthetic resin into a smooth curved surface or a spherical shape having substantially the same shape as a glass bulb of a 75 W type small incandescent bulb. The globe 17 can be combined with another member such as a diffusion film to improve luminance uniformity.

  The lighting circuit 16 accommodated in the cover 14 includes a disk-like circuit board 24 that is horizontally arranged, that is, overlapped with the longitudinal direction of the arc tube 18.

  The arc tube 18 housed in the globe 17 has two first U-shaped bent bulbs 31 and two second U-shaped bent bulbs 31 ', for a total of four in a predetermined position. One discharge path is formed by arranging and sequentially connecting with the communication pipe 32. The first U-shaped bent valve 31 and the second U-shaped bent valve 31 ′ have different bending curvatures and height dimensions at the top.

  Each U-shaped bent bulb 31, 31 ′ has a phosphor film formed on the inner surface and a rare gas such as argon and mercury sealed inside. Each U-shaped bent valve 31, 31 ′ has a tube outer diameter of 7 to 11 mm, specifically a tube outer diameter of 6.8 mm, a tube inner diameter of 5 to 9 mm, specifically 6.0 mm, It is a glass-made cylindrical bulb having a thickness of 0.7 to 1.0 mm, and a bulb having a thickness of about 90 to 120 mm is smoothly curved at an intermediate portion and formed in a substantially U shape having a top portion P. That is, each of the U-shaped bent valves 31, 31 'includes a bent portion 31a that smoothly reverses and a pair of parallel straight portions 31b that are continuous with the bent portion 31a. The arc tube 18 has a bulb height of 40 to 55 mm, a discharge path length of 120 to 200 mm, specifically about 160 mm, and a maximum width in the bulb juxtaposition direction of 30 to 35 mm.

  Each U-shaped bent valve 31, 31 'is sealed at one end with a line seal using a mount or a pinch seal without using a mount, and a narrow tube called an exhaust pipe at the other end. (Not shown) is welded, exhausted, or provided with amalgam as required. In addition, at the end of the second U-shaped bent bulb 31 ′ located at both ends of the arc tube 18, a filament coil is paired with a pair of wells (introduction line, not shown) by a line seal using a mount or the like. It is supported and arranged. Each well is led out to the outside of the second U-shaped bent valve 31 ′ through a jumet wire sealed to the glass at the end of the U-shaped bent valve 31, and is output from the circuit board 24. Connected to the terminal. In addition, auxiliary amalgam may be provided in Wells as needed.

  The first and second U-shaped bent valves 31, 31 'are arranged so that the planes formed by them overlap each other in a parallel state. The two first U-shaped bent valves 31 are arranged in the middle, and the two first U-shaped bent valves 31 'are arranged on both sides of the two first U-shaped bent valves 31'. The shaped valves 31 are juxtaposed so as to be sandwiched between the first U-shaped bent valves 31 ′. Lines connecting the tops of the first and second U-shaped bent valves 31, 31 'are arranged so as to form a straight line. The top portion of the second U-shaped bent valve 31 ′ is positioned on the straight line portion 31 b side with respect to the top portion of the first U-shaped bent valve 31 and is adjacent to the first U-shaped bent valve 31. The second U-shaped bent valves 31 ′ are juxtaposed so as to partially overlap each other.

  The arc tube 18 is arranged in parallel so that the straight portion 31b of the U-shaped bent bulb 31 is positioned in the circumferential direction.

  The arc tube 18 of the bulb-type fluorescent lamp 10 is housed in the globe 17 while being attached to the cover 14. The globe 17 is transparent or light-diffusing milky white or the like, and is formed of glass or synthetic resin into a substantially spherical shape that approximates the glass sphere shape of a mini-krypton type bulb.

  FIG. 3 is a circuit diagram of the lighting circuit 16. As shown in FIG. 3, the lighting circuit 16 includes a filter circuit 51 composed of an impedance element Z1 that is short-circuited with a commercial AC power source e through a fuse F at a voltage between both ends of 330 V and a capacitor C1 having a capacitance of 0.12 μF. The filter circuit 51 is connected to an AC input terminal of a rectifier circuit 52 such as a diode bridge as a full-wave rectifier, and is connected to the DC output terminal side of the rectifier circuit 52 via an inductor L1 having an induction amount of 150 μH. A smoothing capacitor C2 having a capacity of 9 μF is connected to constitute a DC power supply 33. The DC power supply 53 is connected to an inverter circuit 54 as a self-excited half-bridge inverter means serving as an AC-DC converting means. Yes.

  The inverter circuit 54 includes a drain and a source of an N-channel first field effect transistor Q1 having a current value of 3.8 A as a switching element and a P-channel second field effect transistor Q2 having a current value of −2.5 A. The drain and source are connected in series to form a complementary shape. The gate capacitance of the first field effect transistor Q1 and the second field effect transistor Q2 is a resonance capacitance. Further, a parallel circuit of a capacitor C3 as a snubber capacitor having a capacity of 3300 pF and a resistor R1 having a resistance value of 22 kΩ is connected between the drain and source of the second field effect transistor Q2.

  Further, a load circuit 55 is connected between the drain and source of the second field effect transistor Q2, and this load circuit 55 is a DC cut capacitor C4 having a capacitance of 0.1 μF and an inductor having an induction amount of 0.245 mH. One end of the filaments 4a and 4b of the arc tube 18 is connected via an EI12.5 type choke coil L2, and a starting capacitor C5 having a capacity of 3900 pF is connected between the other end of the filament 4a and one end of the filament 4a. Yes. The resonance circuit 56 is formed by the DC cut capacitor C4, the choke coil L2, and the capacitor C5. Since the arc tube 18 has a voltage of 40 V and a current of 0.22 A, the resistance value between the both ends at the time of lighting is 180Ω.

  Furthermore, a gate drive circuit 57 as drive means is connected to the gate of the first field effect transistor Q1 and the gate of the second field effect transistor Q2. The gate driving circuit 37 includes a gate of the first field effect transistor Q1 of the Zener diode ZD1 and the Zener diode ZD2 having a Zener voltage of 24 V, which are connected in series in opposite polarities between the gate and source of the first field effect transistor Q1. And a protection circuit for protecting the second field effect transistor Q2, and in parallel with the series circuit of these Zener diode ZD1, Zener diode ZD2 and capacitor C3, a resonance inductor L3 having an induction amount of 0.47 mH and A feedback circuit 58 of a series circuit of a resonance capacitor C6 having a capacitance of 0.047 μF is connected, and a resistor R2 having a damping function as a discharge circuit having a resistance value of 82 kΩ is connected in parallel to the resonance capacitor C6, and the capacitor C2 and The drain connection point of the first field effect transistor Q1 and the gate of the first field effect transistor Q1. Resistor R3 as an impedance element resistance 470kΩ between the gate of the bets and the second field effect transistor Q2 is connected. Further, an LC series resonance circuit 59 is constituted by an equivalent gate capacitance of the resonance inductor L3, the resonance capacitor C6, and the first field effect transistor Q1 and the second field effect transistor Q2. The resonance capacitor C6 is for removing a direct current component. In addition, a startup resistor R6 is connected in parallel to the series circuit of the Zener diode ZD1 and Zener diode ZD2.

  Note that a chip capacitor is used as the capacitor C3, the capacitor C4, and the resonance capacitor C6, and the characteristics of the chip capacitor are likely to change with changes in temperature, so the circuit board 24 on the side opposite to the side where the arc tube 18 is located is used. Mounting and preventing a decrease in the capacity of the capacitor C6 due to the heat effect of the arc tube 18 ensure the operation.

  Next, the operation of the lighting circuit 16 shown in FIG. 3 will be described. First, the AC voltage of the commercial AC power source e is full-wave rectified by the rectifier circuit 52 and smoothed by the capacitor C2 to be a direct current. When the capacitor C2 is charged, the voltage of the capacitor C2 is applied between both terminals of the first field effect transistor Q1 and the second field effect transistor Q2. In this state, when a voltage is applied to the gates of the first field effect transistor Q1 and the second field effect transistor Q2 via the resistor R3, only the first field effect transistor Q1 is turned on and the voltage of the capacitor C2 is turned on. Is applied to the parallel circuit of the first field effect transistor Q1, the resistor R1, and the capacitor C3, and a current flows through the drain and source of the first field effect transistor Q1, and the parallel circuit of the capacitor C3 and the resistor R1, The first field effect transistor Q1 is turned on.

  In this state, a current flows from the capacitor C2 in the closed circuit of the first field effect transistor Q1, the DC cut capacitor C4, the choke coil L2, the filament 4a, the capacitor C5, the filament 4b, and the capacitor C2, and the capacitor C4 The first field effect transistor Q1 is charged so as to be a positive electrode.

  Thereafter, the current is reversed by the resonance action of the load circuit 55, the polarity of the capacitor C4 is reversed, and the voltages applied to the gates of the first field effect transistor Q1 and the second field effect transistor Q2 are in the opposite directions. The first field effect transistor Q1 is turned off, the second field effect transistor Q2 is turned on, and the inverter circuit 54 is activated. Further, when the voltages applied to the gates of the first field effect transistor Q1 and the second field effect transistor Q2 are inverted, the first field effect transistor Q1 is turned on and the second field effect transistor Q2 is turned off. .

  Thereafter, the voltage of the capacitor C4 with respect to the sources of the first field effect transistor Q1 and the second field effect transistor Q2 becomes negative, and the phase of the drive power source taken out from the capacitor C4 is appropriately adjusted, so that the capacitor C4 The AC component of this capacitor C4 is taken out by reversal of the voltage, the voltage of the resonance capacitor C6 becomes negative, the first field effect transistor Q1 is turned off, and the first field effect transistor Q1 is turned off. When the effect transistor Q2 is turned on, the operating frequency is determined by the LC series resonance circuit 39 of the resonance inductor L3, the first field effect transistor Q1 and the second field effect transistor Q2, and the first field effect transistor Q1 and the second field effect transistor Q1. The field effect transistor Q2 is alternately turned on and off, and a high frequency voltage is applied to the arc tube 18, and the capacitor C5 When the resonance current flowing rises above a predetermined value, the arc tube 18 is started and lighted at a high frequency of about 150 kHz.

  When the threshold voltage of the first field effect transistor Q1 and the second field effect transistor Q2 may be exceeded at the time of start-up, the first field effect transistor Q1 and the first field effect transistor Q1 and the resistance value of the resistor R2 are changed. It is possible to prevent the second field effect transistor Q2 from exceeding the threshold voltage.

  Further, after the discharge lamp lighting device 6 is operated, for example, when the power switch is turned off to cut off the power, the charge charged in the DC cut capacitor C4 is changed to the DC cut capacitor C4, the first electric field effect. The capacitor C4 is discharged when the parasitic diode of the transistor Q1, the resistor R3, the resonance inductor L3, the resistor R2, and the DC cut capacitor C4 are closed, and the resonance capacitor C6 is discharged when the resonance capacitor C6 and the resistor R2 are closed. The Due to this discharge, for example, even if there is no start-up resistor in parallel with the Zener diode ZD1 and Zener diode ZD2, even if the power is turned on again immediately after the power is shut off, the resistor R3 and the capacitor C4 are used. Since the starting current can be reliably supplied, the restart can be ensured.

  Note that the lighting circuit 16 of the present embodiment uses the DC cut capacitor C4 as a feedback element for self-oscillation, but the present embodiment is not limited to this, and a current transformer is connected in series with the load circuit. The field effect transistors Q1 and Q2 may be driven by feedback current generated in the secondary winding of the transformer. Further, in order to omit the current transformer, a drive circuit of a system that obtains a feedback current by magnetically coupling the secondary winding to the current limiting inductor may be used.

  In the case of the lighting circuit 16 shown in FIG. 3, by connecting the resistor R2, for example, the on-time of the second field-effect transistor Q2 is about 30% longer than the on-time of the first field-effect transistor Q1, and the arc tube 4 May flicker. In this case, the on-time of the second field effect transistor Q2 is shortened by using the Zener diode ZD2 as a timing setting means rather than the Zener diode ZD1 and setting the Zener voltage of the Zener diode ZD2 larger than the Zener diode ZD1. The on-time of the first field effect transistor Q1 and the second field effect transistor Q2 can be made substantially equal, and the arc tube 4 can be prevented from flickering. In addition, before the arc tube 4 is started, a closed circuit through which the direct currents of the capacitor C2, the resistor R3, the resistor R6, the resistor R1, and the capacitor C2 can flow can be formed, so that the inverter circuit 34 is reliably started.

  In this way, the bulb-type fluorescent lamp 1 has an input power rating of 10 W, of which about 10% is a loss due to the discharge lamp lighting circuit 6, the lighting frequency is 150 kHz, and 480 lm by using a three-wavelength light emitting phosphor. Is obtained.

  Then, when the bulb-type fluorescent lamp 10 is turned off, power is supplied to the base 12 so that the lighting circuit 16 applies a lamp lighting voltage between the electrodes at both ends of the arc tube 18 to light the arc tube 18. .

  FIG. 4 is a conceptual diagram showing a lighting fixture to which the bulb-type fluorescent lamp 10 of the first embodiment is attached. The lighting fixture L is a downlight embedded in a ceiling S, and is provided with a socket T in which a mini-krypton bulb, which is a small incandescent bulb, is mounted. The bulb-type fluorescent lamp according to the first embodiment. 10 can be mounted, and can be replaced with a highly efficient and long-life bulb-type fluorescent lamp 10.

1 is a side view showing a light bulb shaped fluorescent lamp according to a first embodiment of the present invention. FIG. 2 is a schematic top view partially showing an arc tube portion of the bulb-type fluorescent lamp of FIG. 1. The circuit diagram of the lighting circuit of a bulb-type fluorescent lamp. The conceptual diagram which shows the lighting fixture with which the lightbulb-shaped fluorescent lamp of 1st Embodiment was attached.

Explanation of symbols

10 ... bulb-shaped fluorescent lamp, 12 ... cap, 14 ... cover, 16 ... lighting circuit, 18 ... arc tube, 31 ...
1st U-shaped bent valve, 31 '... 2nd U-shaped bent valve, 31a ... bent part, 31b ... linear part.

Claims (2)

Two first U-shaped bent valves composed of a bent portion having a curved top portion and a pair of straight portions continuous to the bent portion, and a first U-shaped bent shape having a bending curvature and a height dimension of the top portion. Two second U-shaped bent valves smaller than the shaped valve, and the first and second U-shaped bent valves overlap with each other in a state where the planes formed by them are parallel to each other. One U-shaped bent valve is sandwiched between first U-shaped bent valves disposed on both sides of the U-shaped bent valve, and the tops of the first and second U-shaped bent valves are connected to each other. The connecting line forms a straight line, and the top of the second U-shaped bent valve is positioned closer to the straight part than the top of the first U-shaped bent valve, and the adjacent first U-shaped bent The inner part of the valve and the second U-shaped bent valve are arranged side by side so as to overlap each other. One configured with light emitting tube so discharge path is formed;
A cover to which the arc tube is attached and having a base, to which the arc tube is attached;
A lighting circuit housed in the cover;
A bulb-type fluorescent lamp characterized by comprising: An instrument body;
The bulb-type fluorescent lamp according to claim 1 attached to the instrument body;
The lighting fixture characterized by comprising.

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