JP4099627B2 - Discharge lamp lighting device and bulb-type fluorescent lamp - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
  The present invention relates to a discharge lamp lighting device and a bulb-type fluorescent lamp that prevent flickering even when dimming.
[0002]
[Prior art]
  Generally, a discharge lamp lighting device using a smoothing circuit is connected to a phase control type dimmer that controls the phase of an AC voltage of a commercial AC power source using a triac or the like, and the AC voltage input to the discharge lamp lighting device is adjusted to a phase control type. By controlling the phase with an optical device and changing the average voltage, the discharge lamp can be controlled, for example, from the dimming phase of 90 ° to 180 ° without being turned off.
[0003]
[Problems to be solved by the invention]
  However, especially at the lower dimming limit of the phase control dimmer, that is, when the average voltage is low, the triac shows a hysteresis characteristic that the conduction time differs between positive and negative because the load is light, and the peak value of the lamp current is positive and negative. In contrast, there is a problem that the brightness of the discharge lamp may flicker.
[0004]
  The present invention has been made in view of the above problems, and an object of the present invention is to provide a discharge lamp lighting device and a bulb-type fluorescent lamp that prevent flickering of brightness even during dimming.
[0005]
[Means for Solving the Problems]
  The discharge lamp lighting device according to claim 1 is an AC power supply whose output voltage is variable by phase control.Only one of the pair of input lines connected toA DC cut circuit having a capacitor that can be connected in series; a rectifier circuit connected to an AC power supply via the DC cut circuit; a smoothing circuit for smoothing the output of the rectifier circuit; and a discharge connected to the smoothing circuit For example, even if an imbalance between positive and negative peak values due to phase control of an AC power supply occurs, the DC component due to the positive / negative imbalance is cut by a capacitor of the DC cut circuit. The alternating current having no direct current component is supplied to the inverter circuit through the smoothing circuit, and the discharge lamp is turned on by the inverter circuit, thereby preventing the discharge lamp from flickering.
[0006]
  A discharge lamp lighting device according to a second aspect of the present invention is the discharge lamp lighting device according to the first aspect, wherein the DC cut circuit includes a plurality of capacitors connected in series, and can be downsized at low cost.
[0007]
  The discharge lamp lighting device according to claim 3 is the discharge lamp lighting device according to claim 2, wherein the capacitors are connected in series with different polarities by an electrolytic capacitor, and can be reduced in size and size by using an electrolytic capacitor. Capacitance can be achieved, but since an electrolytic capacitor cannot apply a reverse polarity voltage, it is connected in series with different polarities, and different polarities are shared by electrolytic capacitors having different polarities.
[0008]
  The discharge lamp lighting device according to claim 4 is the discharge lamp lighting device according to claim 3, wherein the DC cut circuit is connected to the electrolytic capacitor with a polarity in a direction of conduction when a reverse polarity voltage is applied to the electrolytic capacitor. It has a diode connected in parallel, and even if a reverse polarity voltage is applied to the electrolytic capacitor, it conducts by the diode, so that the reverse polarity voltage is not applied to the electrolytic capacitor. Absent.
[0009]
  The discharge lamp lighting device according to claim 5 is a rectifier circuit that can be connected to an AC power supply whose output voltage is variable by phase control; a smoothing circuit that has a smoothing capacitor and smoothes the output of the rectifier circuit; A hysteresis prevention circuit having a resistor connected to the resistor, a short-circuit means capable of short-circuiting the resistor, and a control means for opening the short-circuit means and connecting the resistor in series with the smoothing capacitor when the average voltage of the AC power supply decreases; Connected to an inverter circuit for lighting a discharge lamp, for example, even if the average voltage of the AC power supply is lowered by phase control to cause an imbalance between positive and negative peak values, the control means of the hysteresis prevention circuit causes a short circuit means Open and connect a resistor in series with the smoothing capacitor to reduce the positive and negative asymmetry of the voltage applied to the inverter circuit. By win, voltage suppress asymmetrical positive and negative is supplied to the inverter circuit, by lighting a discharge lamp by the inverter circuit to prevent flickering of the discharge lamp.
[0010]
  The discharge lamp lighting device according to claim 6 is the discharge lamp lighting device according to claim 5, wherein the control means controls the switching element according to the voltage of the smoothing capacitor, and the smoothing capacitor is a voltage corresponding to the voltage of the AC power supply. Therefore, by controlling the switching element according to the voltage of the smoothing capacitor, it is possible to cope with the average voltage of the AC power supply with a simple configuration.
[0011]
  The discharge lamp lighting device according to claim 7, a rectifier circuit connectable to an AC power supply with variable output voltage by phase control; a smoothing circuit having a smoothing capacitor and smoothing the output of the rectifier circuit; and in series with the smoothing capacitor And an inverter circuit connected to a smoothing circuit for lighting a discharge lamp, wherein the resistor is a hysteresis of the AC power supply. Because the resistance value can suppress the characteristics, a voltage that suppresses positive and negative asymmetry is supplied to the inverter circuit by connecting it in series with a smoothing capacitor. By turning on the discharge lamp by this inverter circuit, the flickering of the discharge lamp is reduced. To prevent.
[0012]
  The discharge lamp lighting device according to claim 8 is the discharge lamp lighting device according to claim 7, wherein the resistance is low when the average voltage of the AC power supply is high and high when the average voltage of the AC power supply is low. Since the hysteresis characteristic is small when the average voltage is high, the resistance value is prevented from decreasing by reducing the resistance value, and when the average voltage is low, the hysteresis characteristic is large and the hysteresis characteristic is suppressed by increasing the resistance value. To do.
[0013]
  The discharge lamp lighting device according to claim 9 is the discharge lamp lighting device according to claim 7 or 8, wherein the resistor is a positive temperature coefficient thermistor, and when the average voltage is high by using the positive temperature coefficient thermistor, the positive temperature coefficient thermistor is used. Since the current flowing through the capacitor is not large, no heat is generated and the resistance value is low. When the average voltage is low, the current flowing through the positive temperature coefficient thermistor is increased to generate heat and the resistance value is high.
[0014]
  A discharge lamp lighting device according to claim 10; a rectifier circuit connectable to an AC power supply with variable output voltage by phase control; a smoothing circuit having a smoothing capacitor and capable of switching to full smoothing to smooth the output of the rectifier circuit; A smoothing circuit switching circuit that switches the smoothing circuit to full smoothing when the average voltage of the AC power supply decreases; and an inverter circuit that is connected to the smoothing circuit and lights the discharge lamp. By applying voltage to the circuit, it is possible to adjust the brightness of the discharge lamp following the voltage of the AC power supply, and when the average voltage drops below a predetermined value, the smoothing circuit is completely smoothed and generated with respect to the frequency of the AC power supply The voltage that suppresses the positive and negative asymmetry is supplied to the inverter circuit, and the discharge lamp is turned on by this inverter circuit, so that the discharge lamp To prevent the variability.
  Claim11The bulb-type fluorescent lamp described above is a fluorescent lamp;10A discharge lamp lighting device according to any one of the above; a cover that houses the discharge lamp lighting device and supports the fluorescent lamp; a base that is electrically connected to the discharge lamp lighting device and that is disposed at the base end of the cover; Each of these functions is achieved.
[0015]
  Claim12The light bulb shaped fluorescent lamp described in claim11The described bulb-type fluorescent lamp includes a globe in which the fluorescent lamp is housed and forms a substantially bulb shape together with a cover, and can be used in place of the bulb with lower power consumption than the bulb.
[0016]
DETAILED DESCRIPTION OF THE INVENTION
  Hereinafter, an embodiment of a light bulb shaped fluorescent lamp of the present invention will be described with reference to the drawings.
[0017]
  FIG. 2 is a side view in which a part of an embodiment of a bulb-type fluorescent lamp is cut out and a globe is seen through, and FIG. 3 is a developed view of a bulb-type discharge lamp of the embodiment and the bulb is turned on. FIG. 4 is an explanatory view showing an electric circuit, and FIG. 4 is a plan view through a partition of the arc tube.
[0018]
  First, as shown in FIG. 2, 11 is a bulb-type fluorescent lamp. The bulb-type fluorescent lamp 11 includes a cover 14 having a base 12, a lighting circuit 16 as a discharge lamp lighting device housed in the cover 14, a transparent A glove 17 having a light property and an arc tube 18 as a discharge lamp housed in the glove 17 are provided. The envelope composed of the base 12, the cover 14, and the globe 17 has an outer shape that approximates the standard size of a general lighting bulb such as an incandescent bulb. For example, the shape of the cover 14 varies depending on the shape of the globe 17. When the globe 17 is A-shaped, the cover 14 cooperates with the globe 17 so that it has a shape close to an A-shaped valve. Shape like a part of a sphere close to a shaped valve. The general lighting bulb is defined in JIS C 7501.
[0019]
  The cover 14 includes a cover main body 21 formed of a heat resistant synthetic resin such as polybutylene terephthalate (PBT). This cover body 21 has a substantially cylindrical shape having an opening that expands downward, and is formed thinly from the middle part to the base end part in order to increase the adaptability to the lighting equipment for incandescent bulbs, and the Edison type at the upper end part A base 12 having a center contact and a base shell is covered and is fixed by an adhesive or a support means such as caulking which is mechanically fixed by a punch. The lighting circuit 16 is connected to the center contact of the base 12 and the base shell.
[0020]
  In addition, 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 having substantially the same shape as a glass bulb of a general lighting bulb such as an incandescent bulb, A fitting edge (not shown) that fits inside the lower end opening of the cover 14 is formed at the edge of the opening. The globe 17 can be combined with another member such as a diffusion film to improve luminance uniformity, or can be omitted.
[0021]
  Further, the lighting circuit 16 includes a circuit board (PC board) 24 arranged horizontally, that is, perpendicularly to the longitudinal direction of the arc tube 18, the upper surface on the both sides of the circuit board 24, that is, the base 12 side, and the arc tube 18. A plurality of electrical components 25 and 26 are mounted on the lower surface which is the side.
[0022]
  The circuit board 24 has a substantially disc shape and has a diameter dimension equal to or smaller than that of a substantially disc having a diameter of about 50 mm. In addition, on the upper surface of the circuit board 24, electrical components 25 such as an electrolytic capacitor and a film capacitor that are relatively weak against heat, that is, relatively low heat resistance, are disposed, and on the bottom surface, they are relatively resistant to heat. That is, the electrical component 26 which is a chip-shaped chip component having a relatively high heat resistance and a small height is disposed. Moreover, it arrange | positions in the reverse cone shape which makes a tall electrical component the vertex.
[0023]
  Further, as shown in FIGS. 2 to 4, the arc tube 18 is a compact translucent discharge vessel formed by bending a discharge path therein, such as soda lime glass, lead glass or barium silicate glass. It has a glass bulb 31 of hard or semi-hard glass such as economical soft glass or borosilicate glass. The inner surface of the glass bulb 31 is provided with a heat-resistant film that converts ultraviolet rays generated by discharge through a protective film mainly composed of alumina fine particles of γ-type or α-type Al2O3 to obtain visible light in a desired wavelength range. A phosphor layer (not shown) coated with a three-wavelength phosphor excellent in characteristics, load characteristics and color rendering properties is formed, whereby the arc tube 18 constitutes a fluorescent lamp. Further, the inside of the glass bulb 31 is filled with a rare gas such as argon as an ionizing medium or a discharge gas containing a mercury or the like, and a pair of electrodes 32 are sealed at both ends of the glass bulb 31 by pinch seals. . Further, as the rare gas, one kind or a plurality of kinds such as argon, krypton, xenon, or neon are mixed and sealed at a pressure of several thousand to several 10000 Pa. If α-type Al 2 O 3 alumina fine particles are used for the protective film, excellent luminous flux rising characteristics are obtained. The phosphor layer may be formed directly on the inner surface without a protective film, or indirectly through a reflective film or the like.
[0024]
  The glass bulb 31 has four tubes 33a, 33b, 33c, and 33d having substantially the same shape. These tubes 33a to 33d have a tube outer diameter of 13 mm or less, preferably 8 to 11 mm, and a small size. 3 mm to 9 mm, for example, a 10 mm glass cross section having a substantially cylindrical shape, and a tube having a length of 110 to 130 mm, which is smoothly curved at the middle part and has a substantially U shape It is formed in a shape. That is, each of the tubular bodies 33a to 33d includes a bent portion 34 that smoothly inverts and a pair of straight pipe portions 35 that are continuous with the bent portion 34 and are parallel to each other. If the outer diameter of the glass bulb 31 is smaller than 3 mm, the lamp current is excessively reduced, and the lamp current becomes small in order to secure a desired lamp input. Since it is necessary to make the discharge path length longer for the minute, it is impossible to reduce the size, and since the lamp voltage becomes higher, the starting voltage becomes higher, the lighting circuit becomes larger, and the cost increases. On the contrary, when the outer diameter of the glass bulb 31 exceeds 13 mm, it becomes too large and it becomes difficult to obtain a compact fluorescent lamp. The inner diameter of the glass bulb 31 is an average value obtained by subtracting from the outer diameter two times the wall thickness approximately proportional to the outer diameter.
[0025]
  Further, both ends of each of the tube bodies 33b and 33c in the middle portion of the glass bulb 31 and one end of each of the tube bodies 33a and 33d at both ends of the glass bulb 31 are sequentially connected via three communication pipe portions 36 that serve as connecting portions. Thus, one continuous discharge path 37 is formed. The communication pipe part 36 is formed by joining openings formed by blowing and breaking the ends of the pipe bodies 33a to 33d with a burner. The glass bulb 31 is formed so that the length of the discharge path 37 is about 250 mm to 500 mm according to the lamp power.
[0026]
  In the state where the glass bulb 31 is incorporated in the bulb-type fluorescent lamp 11, the bent portion 34 which is the top of each of the tubes 33a to 33d is centered on a central axis whose longitudinal direction is the vertical direction of the bulb-type fluorescent lamp 11. The straight tube portions 35 of the tubular bodies 33a to 33d are also equally spaced on a predetermined circumference centered on the central axis of the bulb-type fluorescent lamp 11. In other words, the straight pipe portions 35 of the pipe bodies 33a to 33d are arranged corresponding to the sides of the quadrangular cross section.
[0027]
  In addition, cylindrical thin tubes 38a, 38b, 38c, and 38d, which are also called exhaust pipes, protrude from one end of each of the tubular bodies 33a to 33d in a communicating state. However, the thin tubes 38a and 38d of the tube bodies 33a and 33d at both ends of the glass bulb 31 protrude from the end on the non-electrode side, which is opposite to the end where the electrode 32 is sealed. These thin tubes 38a to 38d are sequentially sealed by fusing in the manufacturing process of the glass bulb 31, and the inside of the glass bulb 31 is exhausted through a part of each of the thin tubes 38a to 38d that is not sealed. Is sealed by fusing an unsealed part of each of the capillaries 38a to 38d, for example, the capillaries 38b.
[0028]
  Further, each electrode 32 has a filament coil 41 in which, for example, a tungsten (W) wire is wound twice and an oxide of an alkaline earth metal electron emitting material is applied, and the filament coil 41 is a pair of two wires. Is supported by a well 42 for electrode. Each well 42 is connected to a wire 44 led out of the tubes 33a and 33d through a jumet wire 43 sealed by pinch seals at the ends of the tubes 33a and 33d at both ends of the glass bulb 31. ing. This jumet wire 43 is sealed by a pinch seal portion 45 at the valve end. The wire 44 is connected to the lighting circuit 16 when the glass bulb 31 is incorporated into the bulb-type fluorescent lamp 11. Further, each electrode 32 may have a bead mount structure in order to prevent the filament coil 41 from being disturbed during sealing.
[0029]
  In addition, the pinch seal part 45 sealed with the pinch seal is formed in the edge part of each tubular body 33a-33d.
[0030]
  In addition, the main amalgam 51 serving as a source of mercury as an ionization medium when the thin tube 38a is sealed is sealed in the thin tube 38c of the one intermediate tube body 33c. The main amalgam 51 is a Bi—In—Hg alloy composed of bismuth, indium and mercury, and is approximately spherical and has a particle diameter of about 2.5 mm and is sealed in an amount of about 40 to 120 mg. The mercury vapor pressure inside is controlled to an appropriate range. In addition, as the main amalgam 51, in addition to bismuth and indium, for example, Bi-In-Sn-Hg may be used which is formed of an alloy that combines tin, lead, and the like. In addition, when the mercury content is about 6% by mass, mercury tends to ooze out on the surface of the amalgam and cause stickiness. Therefore, when producing the amalgam, it is cooled rapidly to reduce crystal particles, or to the surface of the amalgam. It is preferable to perform an anti-sticking treatment. Further, as the outer diameter of the glass bulb 31 becomes smaller, it becomes easier for the mercury vapor pressure in the discharge space to be evenly distributed during lighting, so the main amalgam 51 may be supplied at a plurality of positions of the glass bulb 31. .
[0031]
  Further, the end portion of each intermediate tube body 33b, 33c on the side that does not have the thin tubes 38b, 38c opposite to the thin tubes 38b, 38c is located in the middle of the discharge path 37, and is turned off when the glass is turned off. An auxiliary amalgam 52 is provided in the middle of two discharge paths that adsorbs the floating mercury in the bulb 31 and releases the mercury adsorbed at the beginning of lighting including at the time of starting. That is, the main amalgam 51 is disposed at the end of the tube 33c sandwiched between the two auxiliary amalgams 52 that serve as a source of mercury as an ionization medium in the middle of the discharge path of the glass bulb 31.
[0032]
  The auxiliary amalgam 52 has a rectangular plate shape that is long in the axial direction of the tubes 33b and 33c, and has a substrate 53 made of, for example, SUS. One end of the substrate 53 is made of nickel (Ni) and is a single linear support. It is attached by welding to a well 54 for auxiliary amalgam as a member. The substrate 53 is provided with a metal plating 55 such as indium (In) that adsorbs mercury at a place away from the welded place with the wells 54. Then, by applying the metal plating 55 to the place away from the welded place with the wells 54, the indium of the metal plating 55 melts and reaches the wells 54 when the lamp is lit, so that an alloy is formed by the reaction of nickel and indium in the wells 54. This prevents the mercury vapor pressure characteristics from being impaired and prevents deterioration of the rising characteristics of the luminous flux during start-up due to use over time.
[0033]
  Further, an auxiliary amalgam 56 on the electrode side serving as an auxiliary conductor is attached to one well 42 of the electrode 32 of each of the tubular bodies 33a and 33d at both ends. The auxiliary amalgam 56 is configured in the same manner as the auxiliary amalgam 52 and has similar mercury vapor pressure characteristics.
[0034]
  Further, the distance L between the pinch seal portion 45 which is an end portion of the intermediate tube bodies 33b and 33c where the auxiliary amalgam 52 of the glass bulb 31 is disposed and the communication tube portion 36 is formed in a range of 8 to 15 mm. By doing so, the pinch seal portion 45, which is a sealing portion, becomes a high temperature by reducing the thermal effect of the wells 54 during the connecting process of connecting the pipe bodies 33a to 33d with the communication pipe portion 36. It is possible to prevent cracks from occurring.
[0035]
  Further, the arc tube 18 is attached to a partition plate 61 as a support means which is a fluorescent lamp fixing member and a lighting circuit fixing member, and the partition plate 61 is fixed to the cover 14. That is, the partition plate 61 includes a disk-shaped substrate portion 62, and after inserting the end portions of the tubular bodies 33a to 33d into the mounting holes 62a formed in the substrate portion 62, for example, with a silicone adhesive The arc tube 18 is fixed to the partition plate 61 by bonding or the like. In addition, a fitting step portion 63 is formed from the outer peripheral portion of the substrate portion 62 toward the upper side and further toward the outer side. Then, the fitting step 63 is fitted inside the cover 14, and the fitting step of the globe 17 is fitted between the fitting step 63 and the cover 14. These members are fixed to each other by, for example, filling a silicone adhesive between the portion 63 and the cover 14. Further, a mounting piece 64 having a cylindrical shape or the like is projected on the upper side of the fitting step 63, and the circuit board 24 of the lighting circuit 16 is attached to the mounting piece 64 by fitting or bonding. It has been.
[0036]
  Next, the lighting circuit 16 will be described with reference to FIG.
[0037]
  FIG. 1 is a circuit diagram showing a lighting circuit. As shown in FIG. 1, a two-wire dimmer 71 is connected to a commercial AC power source e, and phase control is performed by the commercial AC power source e and the dimmer 71. An AC power supply 72 with variable output voltage is configured. The 2-wire dimmer 71 includes a triac Q1, a noise absorbing capacitor C1 is connected in parallel to the triac Q1, and a trigger diac Q2 is connected to the gate of the triac Q1. The diac Q2 is connected to one end side of the triac Q1 through the variable resistor R1 for setting the phase angle, and is connected to the other end side of the triac Q1 through the capacitor C2. Then, changing the resistance value of the variable resistor R1 changes the time constant of the variable resistor R1 and the capacitor C2, changes the phase at which the triac Q1 turns on, changes the average voltage, and turns on all light and dimming Set.
[0038]
  In addition, an impedance element Z1 is connected to the commercial AC power source e via the dimmer 71, and a capacitor C3 is connected in parallel to the impedance element Z1. The commercial AC power source e via the dimmer 71 is connected to the input terminal of a full-wave rectifier circuit 74 composed of four diodes D1 to D4 via a DC cut circuit 73. The DC cut circuit 73 is formed by connecting two electrolytic capacitors C4 and C5 of 220 μF or more in series with the commercial AC power source e in series with opposite polarities in series. A diode D5 that prevents the reverse voltage of the electrolytic capacitor C4 from being connected in a direction that conducts when a reverse polarity voltage is applied to the capacitor C4 is connected to the electrolytic capacitor C5. A diode D6 is connected to prevent the reverse voltage of the electrolytic capacitor C5 with a polarity in the direction of conduction when applied. In the case of a capacitor having no polarity in the DC cut circuit 73, only one capacitor may be provided in series with the commercial AC power source e. In either case, in the case of the 100V, 20W class, 100 μF. For example, about 330 μF may be used. Further, although depending on the state of hysteresis, a film capacitor of about 40 V or less may be used.
[0039]
  Further, a series circuit of an inductor L1 and a resistor R2 is connected to the output terminal of the full-wave rectifier circuit 74, and a filter circuit 75 is configured to remove generated high-frequency noise so as not to flow into the commercial AC power source e.
[0040]
  Then, the partial smoothing circuit 76 that forms the partial smoothing voltage by filling the valley of the non-smoothing DC voltage output from the full-wave rectification circuit 74 with the peak value of the non-smoothing DC voltage remaining as it is in the resistor R2. Is connected. In this partial smoothing circuit 76, a capacitor C6 for high frequency bypass is connected in parallel with the resistor R2, and in parallel with this capacitor C6, an electrolytic capacitor C7, a diode D7, a resistor R3, an electrolytic capacitor C8, a resistor R4 and A series circuit of the resistor R5 is connected, and a diode D8 is connected between the connection point of the electrolytic capacitor C7 and the diode D7 and the negative electrode of the full-wave rectifier circuit 74, with a reverse polarity to the diode D7, and the electrolytic capacitor C7, the diode D7, and the resistor A reverse polarity diode D9 is connected in parallel with the series circuit of R3.
[0041]
  The partial smoothing circuit 76 is connected to a half-bridge type inverter circuit 77. This inverter circuit 77 has two complementary N-channel MOS field effect transistor Q4 and P-channel MOS field effect transistor Q5 connected in series, and has a frequency of 10 kHz or more, preferably a frequency of 20 to 200 kHz. Outputs high-frequency alternating current. The field effect transistor Q4 and the field effect transistor Q5 are connected to one end of a commercial AC power source e via a starting resistor R6 and a resistor R7, and the starting resistor R8 is connected between the drain and source of the field effect transistor Q5. A capacitor C11 is connected in parallel. Furthermore, a series circuit of a Zener diode ZD1 and a Zener diode ZD2 connected in reverse polarity is connected between the gate and source of the field effect transistor Q4, and a secondary winding Tr1b of the capacitor C12 and the feedback transformer Tr1 is connected. ing. A series circuit of a capacitor C13 and a field effect transistor Q6 is connected in parallel with the secondary winding Tr1b of the feedback transformer Tr1.
[0042]
  The field effect transistor Q3 is a part of the protection circuit 78 that stops the oscillation when the dimming is below the lower limit, and this protection circuit 78 is connected between the connection point of the resistor R3 and the electrolytic capacitor C8 and the resistor R4, and the Zener diode ZD3 , A series circuit of a resistor R8 and a resistor R9 is connected, a capacitor C14 is connected in parallel to the resistor R9, and a gate of the field effect transistor Q7 is connected to a connection point of the resistor R8 and the resistor R9, and the field effect transistor Q7 Is connected to the connection point of the resistor R3 and the electrolytic capacitor C8 via the resistor R11, and the capacitor C15 is connected in parallel to the resistor R12. Further, the connection point of the resistor R8 and the resistor R9 is connected to the drain of the field effect transistor Q3 through the resistor R13 and the diode D11, and the drain of the field effect transistor Q3 is connected to the field effect transistor Q4 and the field effect through the diode D12. Connected to the gate of transistor Q5. The drain of the field effect transistor Q3 is connected to the inductor L1 via a series circuit of a diode D13, a resistor R14, a resistor R15, and a resistor R16. Further, the connection point of the diode D13 and the resistor R14 is connected to the connection point of the field effect transistor Q4 and the field effect transistor Q5 via the series circuit of the Zener diode ZD4, the resistor R17, and the resistor R18. The connection point is connected to the gate of the field effect transistor Q6.
[0043]
  Further, a load circuit 79 is connected between the drain and source of the field effect transistor Q5. This load circuit 79 is composed of a primary winding Tr1a from the feedback transformer Tr1 to a series winding Tr2a of a step-up transformer Tr2 of a single winding transformer, a resistor The common winding Tr2a of the step-up transformer Tr2 is connected to the series circuit of R18 and the DC cut capacitor C16, and the filament coils 41 and 41 of the arc tube 18 are connected via the series winding Tr2b, the resistor R18 and the current limiting inductor L2, respectively. A series circuit of a starting capacitor C17 and a resistor R19 is connected between the other ends of the filament coils 41 and 41.
[0044]
  Next, the operation of the lighting circuit 16 of the above embodiment will be described.
[0045]
  First, the case where the dimmer 71 is not connected or the dimmer 71 is set to the all-light lighting state will be described. The lighting circuit 16 can correspond to either a commercial AC power source e to which the dimmer 71 is connected or a commercial AC power source e to which the dimmer 71 is not connected.
[0046]
  The voltage of the commercial AC power source e is applied to the resistor R8 and the capacitor C11 via the resistor R6, the resistor R7, the Zener diodes ZD1, ZD2 or the resistor R7, the capacitor C12, the secondary winding Tr1b of the feedback transformer Tr1, and the field effect transistor Q4 Turn on.
[0047]
  When the field effect transistor Q4 is turned on, from the partial smoothing circuit 76, the field effect transistor Q4, the primary winding Tr1a of the feedback transformer Tr1, the series winding Tr2b of the step-up transformer Tr2, the inductor L2, the filament coil 41, the capacitor C17, the resistor R19, A voltage is applied to the filament coil 41, the capacitor C16, and the resistor R4, and one of the field effect transistor Q4 and the field effect transistor Q5 that is on is turned off and the other is turned on mainly due to resonance of the capacitor C17 and the current limiting inductor L2. To do.
[0048]
  This operation is repeated to generate a high-frequency AC voltage, the filament coils 41 and 41 are preheated, and when the voltage between the filament coils 41 and 41 reaches a predetermined value or more, the arc tube 18 is started and lit.
[0049]
  Further, each of the electrolytic capacitors C7 and C8 of the partial smoothing circuit 76 is charged with a voltage that is ½ of the peak value of the non-smoothed DC voltage by the smoothed DC voltage from the full-wave rectifying circuit 74. On the other hand, during the discharge, the electrolytic capacitors C7 and C8 are discharged in parallel by the diodes D7 to D9. For this reason, valley portions in the half-wave rectified waveform of the commercial AC power source e are filled, and so-called partial smoothing voltages are generated in the electrolytic capacitors C7 and C8. By using the partial smoothing circuit 76 in this way, the conduction angle of the non-smooth DC voltage changes due to dimming. In the partial smoothing circuit 76, the partial wave from the full-wave rectifier circuit 74 depends on the conduction angle of the non-smooth DC voltage. As the magnitude of the input current flowing into the smoothing circuit 76 changes, the smoothed DC voltage also changes. For this reason, the change in conduction angle due to dimming and the magnitude of the lamp current supplied to the arc tube 18 show a correlation, and the dimming is smooth and the dimming characteristics are good. Also, when the input voltage increases, the Zener diode ZD4 is turned on and the field effect transistor Q6 is turned on, so that the capacitor C13 is electrically connected, the oscillation frequency of the field effect transistor Q4 and the field effect transistor Q5 is lowered, and the lamp current Increases and the arc tube 18 becomes brighter.
[0050]
  Further, by operating the variable resistor R1 of the dimmer 71, the phase angle at which the diac Q2 operates is changed, the conduction phase angle of the triac Q1 is changed, the average voltage is lowered, and the arc tube 18 is dimmed. That is, when the input voltage is lowered by dimming, the Zener diode ZD4 is turned off and the field effect transistor Q6 is turned off, so that the capacitor C13 is not electrically connected, and the field effect transistor Q4 and the field effect transistor Q5 The oscillation frequency increases, the lamp current decreases, and the arc tube 18 becomes dark. And, for example, deep dimming increases the phase angle, and the triac Q1 operates positively and negatively.SymmetryIn the case of partial smoothing circuit 76, the positive / negative imbalance is output as it is to inverter circuit 77 and input to arc tube 18 when hysteresis occurs in the input current and an imbalance between the positive and negative peak values occurs. Current has a positive / negative asymmetric hysteresis, the peak value differs depending on the positive / negative, and the arc tube 18 may flicker. However, by cutting the DC component in which hysteresis occurs due to the asymmetrical operation of the TRIAC Q1 with the electrolytic capacitors C4 and C5 of the DC cut circuit 73, AC with no DC component is supplied to the inverter circuit 77 via the partial smoothing circuit 76. In addition, since the crest values are positive and negative and are equally positive and negative symmetric, flickering of the arc tube 18 can be prevented.
[0051]
  Furthermore, when the light is dimmed above the lower limit, the voltage of the electrolytic capacitor C8 decreases, the Zener diode ZD3 is turned off, the electrolytic transistor Q7 is turned off, and the field effect transistor 3 is turned on. Since the gate of the field effect transistor Q5 falls to the negative potential of the full wave rectifier circuit 74, the field effect transistor Q4 is turned off and the oscillation of the inverter circuit 77 is stopped.
[0052]
  According to the experiment, when the DC cut circuit 73 is not provided, as shown in FIG. 5A, the input voltage waveform is positive and negative and the peak value is different and becomes asymmetrical between positive and negative, as shown in FIG. 5B. The lamp current of the arc tube 18 flickers with different peak values for every 50 Hz of the frequency of the commercial AC power source e.
[0053]
  However, by providing a DC cut circuit 73 having electrolytic capacitors C4 and C5 connected in series to a commercial AC power supply e, as shown in FIG. 6 (a), even if unbalanced switching of the triac Q1 occurs, it is positive or negative. The direct current component due to the difference in the peak value is cut, and the influence of hysteresis is reduced. As shown in FIG. 6B, the lamp current of the arc tube 18 has a constant peak value, and thus flicker does not occur.
[0054]
  Further, since the diodes D5 and D6 are connected to the electrolytic capacitors C4 and C5, respectively, as shown in FIG. 6C, no reverse voltage is applied to either of the electrolytic capacitors C4 and C5. There is no adverse effect on C5.
[0055]
  Next, a lighting circuit 16 according to another embodiment will be described with reference to FIG.
[0056]
  FIG. 7 is a circuit diagram showing the lighting circuit. In the lighting circuit 16 shown in FIG. 1, the impedance circuit Z1 is not provided, and the inductor L3 and the capacitor C3 are connected in series to the filter circuit 75 triac Q1. Yes.
[0057]
  The partial smoothing circuit 76 has a series circuit of an electrolytic capacitor C21, a diode D21, an electrolytic capacitor C22, a diode D22, an electrolytic capacitor C23, and a resistor R21 connected between the output terminals of the full-wave rectifier circuit 74, and the electrolytic capacitor C21 and The diode D23 is connected in parallel to the series circuit of the diode D21, the diode D24 is connected in parallel to the series circuit of the diode D21, the electrolytic capacitor C22, the diode D22, the electrolytic capacitor C23, and the resistor R23, the diode D22, the electric field A diode D25 is connected in parallel to the series circuit of the capacitor C23 and the resistor R21, and a diode D26 is connected in parallel to the series circuit of the electrolytic capacitor C21, the diode D21, and the electrolytic capacitor C22. Then, each of the electrolytic capacitors C21, C22, and C23 of the partial smoothing circuit 76 is charged with a voltage that is 1/3 of the peak value of the non-smoothed DC voltage by the smoothed DC voltage from the full-wave rectifier circuit 74. On the other hand, during the discharge, the electrolytic capacitors C21, C22, C23 are discharged in parallel by the diodes D21 to D26.
[0058]
  Further, in the hysteresis prevention circuit 81, a field effect transistor Q11 as a switching element is connected in parallel to the resistor R21, and the gate of the field effect transistor Q11 is a diode via a series circuit of a Zener diode ZD5 and a resistor R22. It is connected to the connection point of D22 and electrolytic capacitor C23, and is connected to the negative electrode of full-wave rectifier circuit 74 through a parallel circuit of resistor R23 and capacitor C24.
[0059]
  Further, the resistor R3, the resistor R4, the field effect transistor Q6, the resistor R8, the Zener diode ZD4, the resistor R15, and the resistor R16 are not provided. Further, a resistor R24 is connected to the gate of the field effect transistor Q4, and a resistor R25 is connected to the gate of the field effect transistor Q5.
[0060]
  A DC cut capacitor C25 is connected in series with the common winding Tr2a of the step-up transformer Tr2, and the primary winding Tr3a of the filament transformer Tr3 for preheating the filament coil 41 is connected to the series winding Tr2b of the step-up transformer Tr2. Are connected, and a filament coil 41 is connected to the secondary winding Tr3b of the filament transformer Tr3. A starting capacitor C26 is connected between the filament coils 41 and 41.
[0061]
  Next, the operation of the lighting circuit 16 shown in FIG. 7 will be described.
[0062]
  The basic operation is the same as that of the lighting circuit 16 shown in FIG.
[0063]
  Then, since the voltage from the partial smoothing circuit 76 is high at the time of all-light lighting, the arc tube 18 is turned on in all light with an increased input current. Further, since the voltage charged in the electrolytic capacitor C23 is high, the Zener diode ZD5 is turned on and the field effect transistor Q11 is turned on, so that the resistor R21 is short-circuited, and the resistor R23 is electrically connected in series with the electrolytic capacitor C23. Not connected. Therefore, the partial smoothing circuit performs the partial smoothing according to the output voltage of the full-wave rectifier circuit 74 as usual, and the efficiency does not decrease because the resistor R21 is not connected.
[0064]
  On the other hand, since the voltage from the partial smoothing circuit 76 is low at the time of dimming lighting, the arc tube 18 is dimmed with a small input current. In addition, since the voltage charged to the electrolytic capacitor C23 is lower than a predetermined value because the average voltage is reduced, the Zener diode ZD5 is turned off and the field effect transistor Q11 is turned off, so that the resistor R23 is connected in series to the electrolytic capacitor C23. It will be in the state. Therefore, for example, deep dimming increases the phase angle, and the triac Q1 operates positively and negatively.SymmetryIf this is not the case, even if hysteresis occurs in the input current and the positive and negative peak values are unbalanced, the hysteresis of the output voltage of the partial smoothing circuit 76 can be suppressed by suppressing the voltage waveform in which the hysteresis occurs with the resistor R21. Flickering of the arc tube 18 can be prevented because the peak values are equal and positive and negative and are symmetrical.
[0065]
  In the case of all light, the input power factor is about 60% in the case of the full smoothing circuit. However, by using the partial smoothing circuit 76, the input power factor can be increased to 85% or more, and the electrolytic capacitors C21, C22, The current flowing through C23 is small and the input current is small.
[0066]
  According to the experiment, when the hysteresis prevention circuit 81 is not provided, as shown in FIG. 8A, the input voltage waveform is positive and negative and the peak value is different and becomes asymmetrical between positive and negative, as shown in FIG. 8B. The input current also becomes asymmetric between positive and negative, and as shown in FIG. 8C, the lamp current of the arc tube 18 has flickers with different peak values for every 50 Hz of the frequency of the commercial AC power source e.
[0067]
  However, by providing the hysteresis prevention circuit 81 in which the resistor R21 is connected in series with the electrolytic capacitors C21, C22, and C23, as shown in FIG. 9A, the input voltage waveform is positive and negative, the peak value is different, and positive and negative asymmetrical. Even if unbalanced switching of the triac Q1 occurs, the difference between the positive and negative peak values is suppressed by the resistor R21, and the influence of hysteresis is reduced as shown in FIG. As shown in c), the lamp current of the arc tube 18 does not flicker because the peak value is constant.
[0068]
  Next, a lighting circuit 16 according to another embodiment will be described with reference to FIG.
[0069]
  10 is a circuit diagram showing a lighting circuit. In the lighting circuit 16 shown in FIG. 7, a hysteresis prevention circuit is provided between the diode D22 and the electrolytic capacitor C23.82Are connected. This anti-hysteresis circuit 82 connects a series circuit of a resistor R27 and a resistor R28 between a diode D22 and an electrolytic capacitor C23, and has a positive temperature characteristic such as a so-called posistor in parallel with the series circuit of the resistor R27 and the resistor R28. A PTC thermistor R29 is connected. Resistor R27 and R28 are 10Ω, PTC thermistor is 10Ω during all light, and inrush current increases during dimming, and the temperature rises due to heat generation, resulting in a temperature of 1 kΩ or more, and the combined resistance during all light is 6.7Ω. The combined resistance is set to 20Ω. Since the hysteresis can be suppressed when the resistance is set to about 10Ω to 100Ω, the hysteresis can be suppressed when the combined resistance is 20Ω.
[0070]
  Next, the operation of the lighting circuit 16 shown in FIG. 10 will be described.
[0071]
  The basic operation is the same as that of the lighting circuit 16 shown in FIG.
[0072]
  Since there is no large inrush current during all-light lighting, the PTC thermistor R29 does not generate much heat and has a low resistance value. Therefore, the partial smoothing circuit performs normal smoothing according to the output voltage of the full-wave rectifier circuit 74 as usual, and the resistance of the PTC thermistor R29 is low, so that the efficiency does not decrease.
[0073]
  On the other hand, at the time of dimming lighting, the PTC thermistor R29 generates heat due to the inrush current and the resistance value increases. Therefore, for example, deep dimming increases the phase angle and the operation of the triac Q1SymmetryIf this is not the case, even if hysteresis occurs in the input current and the positive and negative peak values are unbalanced, the hysteresis of the output voltage of the partial smoothing circuit 76 can be suppressed by suppressing the voltage waveform in which the hysteresis occurs with the resistor R21. Flickering of the arc tube 18 can be prevented because the peak values are equal and positive and negative and are symmetrical.
[0074]
  next,The prerequisite technology of the present inventionThe lighting circuit 16 will be described with reference to FIG.
[0075]
  FIG. 11 is a circuit diagram showing a lighting circuit. In the lighting circuit 16 shown in FIG. 1, the filter circuit 75 is the same as that in FIG. 7, and the protection circuit 78 is removed. In the lamp current control circuit 83, the base of the transistor Q8 is connected to the connection point of the diode D7 and the resistor R3 through a series circuit of the Zener diode ZD6 and the resistor R31, and a capacitor C32 is connected between the collector and emitter of the transistor Q8. Is connected. Further, a series circuit of a resistor R32 and a resistor R33 is connected in parallel to the electrolytic capacitor C8, a parallel circuit of a capacitor C33 and a Zener diode ZD7 is connected in parallel to the resistor R33, and a connection of the resistor R32 and the resistor R33 is connected. The point is connected to the emitter of the transistor Q9 via a resistor R34, and a resistor R35 is connected between the emitter and base of the transistor Q9 via a resistor R34. The collector of the transistor Q9 is connected to the negative electrode of the full-wave rectifier circuit 74 via the resistor R36, and the capacitor C34 is connected in parallel to the resistor R36. Further, the collector of the transistor Q34 is connected to the gate of the field effect transistor Q6 via the diode D31. Further, a current detection resistor R37 is connected to the filament coil 41 of the arc tube 18 in the path through which the lamp current flows, and this resistor R37 is connected to the collector of the transistor Q8 via the diode D32.
[0076]
  Further, the load circuit 79 has a DC cut capacitor C35 connected in series with the primary winding Tr1a of the feedback transformer Tr1, and a DC cut capacitor C36 connected to the common winding Tr2a of the step-up transformer Tr2. Has been. The primary winding Tr4a of the filament preheating transformer Tr4 for filament preheating is connected to the series winding Tr2b of the step-up transformer Tr2, and the secondary windings Tr4b and Tr4c of the filament preheating transformer Tr4 are connected to the filament coils 41 and 41, respectively. It is connected.
[0077]
  Next, the abovePrerequisite technologyThe operation of the lighting circuit 16 will be described.
[0078]
  The basic operation is the same as that of the lighting circuit 16 shown in FIG.
[0079]
  First, when the all-light lighting state is set and the input voltage increases, the charging voltage of the electrolytic capacitor C8 increases, so the Zener diode ZD6 is turned on and the transistor Q8 is turned on, so the transistor Q9 is turned on and the charging voltage of the capacitor C34 is turned on. Becomes higher. For this reason, the apparent resistance value of the field effect transistor Q6 is lowered and the capacitor C13 is electrically connected, the oscillation frequency of the field effect transistor Q4 and the field effect transistor Q5 is lowered, the lamp current is increased, and the arc tube 18 is increased. Becomes brighter.
[0080]
  On the other hand, by operating the variable resistor R1 of the dimmer 71, the phase angle at which the diac Q2 operates is changed, the conduction phase angle of the triac Q1 is changed, the average voltage is lowered, and the arc tube 18 is dimmed. That is, when the input voltage decreases due to dimming, the charging voltage of the electrolytic capacitor C8 decreases, so the Zener diode ZD6 turns off and the transistor Q8 turns off, so that the capacitor C13 is not electrically connected, and the electric field The oscillation frequency of the effect transistor Q4 and the field effect transistor Q5 increases, the lamp current decreases to a predetermined value, and the arc tube 18 becomes dark. Further, when the current flowing through the resistor 37 increases to, for example, about 20 mA, the transistor Q3 is turned off to hold the peak of the lamp current so that the lamp current does not rise above a predetermined value. Therefore, for example, deep dimming increases the phase angle, and the triac Q1 operates positively and negatively.versus NameIf this is not the case, even if hysteresis occurs in the input current and an unbalance between the positive and negative peak values occurs, flickering of the arc tube 18 can be prevented by reducing the lamp current to be constant at a predetermined value. In addition, by reducing the peak value of the lamp current to a predetermined value or less, even if hysteresis occurs, the lamp current is clipped to a predetermined value or less, so that flicker can be prevented.
[0081]
  According to experiments, as shown in FIG. 12 (a), when a positive / negative asymmetric input voltage with different peak values is applied, as shown in FIG. 12 (b), when there is no lamp current control circuit 83, as shown in FIG. On the other hand, the lamp current has a different peak value and flickers. By providing the lamp current control circuit 83, the peak of the current higher than necessary is suppressed by clipping the lamp current at a predetermined peak value. The crest value becomes nearly constant, and the lamp current of the arc tube 18 does not flicker because the crest value becomes constant as shown in FIG.
[0082]
  Next, a lighting circuit 16 according to another embodiment will be described with reference to FIG.
[0083]
  FIG. 13 is a circuit diagram showing the lighting circuit. In the lighting circuit 16 shown in FIG. 11, the circuit related to the output control based on the frequency of the inverter circuit 78 is removed. The smoothing system switching circuit 84 connects the series circuit of the diode D32 and the resistor R41 and the series circuit of the diode D33 and the resistor 42 to the input terminal of the full-wave rectifier circuit 74, and connects the connection point of the resistors R41 and R42 to the capacitor. The full-wave rectifier circuit 74 is connected to the negative electrode via C41. In addition, a series circuit of a Zener diode ZD8 and a resistor R41 is connected in parallel to the capacitor C41, a capacitor C42 is connected in parallel to the resistor R43, and the connection point of the Zener diode ZD8 and the resistor R43 is connected to the transistor Q11. The base is connected. A capacitor C43 is connected between the collector and emitter of the transistor Q11, and the collector of the transistor Q11 is connected to the gate of the field effect transistor Q12. Further, the drain and source of the field effect transistor Q12 are connected between both ends of the diode D8. The connection point between the resistors R41 and R42 is connected to the gate of the field effect transistor Q12 via the resistor R44.
[0084]
  Next, the operation of the lighting circuit 16 shown in FIG. 13 will be described.
[0085]
  The basic operation is the same as that of the lighting circuit 16 shown in FIG.
[0086]
  First, when the all-light lighting state is set and the input voltage increases, the charging voltage of the capacitor C41 increases, so the Zener diode ZD8 is turned on and the transistor Q11 is turned on, so that the field effect transistor Q12 is turned off and the partial smoothing circuit 76 is turned on. Functions as partial smoothing. Further, since the dimmer 71 is set to all light, the voltage input to the partial smoothing circuit 76 and the inverter circuit 77 is increased, the lamp current is increased, and the arc tube 18 is brightened.
[0087]
  On the other hand, by operating the variable resistor R1 of the dimmer 71, the phase angle at which the diac Q2 operates is changed, the conduction phase angle of the triac Q1 is changed, the average voltage is lowered, and the arc tube 18 is dimmed. That is, when the input voltage decreases due to dimming, the charging voltage of the capacitor C41 decreases, so the Zener diode ZD8 turns off and the transistor Q11 turns off, so that the field effect transistor Q12 turns on and the output of the full-wave rectifier circuit 74 The capacitor C7 is electrically connected between the terminals. Therefore, for example, deep dimming increases the phase angle and the operation of the triac Q1SymmetryIf this is not the case, even if hysteresis occurs in the input current and an imbalance between the positive and negative peak values occurs, the partial smoothing circuit 76 performs full-wave rectification, so the lamp current is smoothed and flickering of the arc tube 18 is prevented. it can.
[0088]
  According to experiments, as shown in FIG. 14 (a), when a positive / negative asymmetric input voltage with different peak values is applied as shown in FIG. In addition, the lamp current has a different peak value and flickers, but by providing the smoothing method switching circuit 84, the partial smoothing circuit 76 is completely smoothed so that the voltage input to the inverter circuit 77 is completely smoothed. As shown in FIG. 14C, the lamp current of the arc tube 18 does not flicker because the peak value is constant.
[0089]
  The dimmer 71 does not generally constitute the bulb-type fluorescent lamp 11, but is embedded in a wall surface of the room or built in a lighting fixture. Can be incorporated.
[0090]
【The invention's effect】
  According to the discharge lamp lighting device according to claim 1, even if an unbalance of positive and negative peak values by phase control of the AC power supply occurs, the DC component due to the positive / negative imbalance is cut by the capacitor of the DC cut circuit, Alternating current having no DC component is supplied to the inverter circuit via the smoothing circuit, and the discharge lamp is turned on by the inverter circuit, thereby preventing the discharge lamp from flickering.
[0091]
  According to the discharge lamp lighting device of the second aspect, in addition to the discharge lamp lighting device of the first aspect, the DC cut circuit can be miniaturized at low cost because a plurality of capacitors are connected in series.
[0092]
  According to the discharge lamp lighting device according to claim 3, in addition to the discharge lamp lighting device according to claim 2, it is possible to reduce the size and increase the capacity by using an electrolytic capacitor. Since it cannot be connected, it is possible to share voltages having different polarities by connecting the capacitors in series with different polarities and using electrolytic capacitors having different polarities.
[0093]
  According to the discharge lamp lighting device of the fourth aspect, in addition to the discharge lamp lighting device of the third aspect, even when a reverse polarity voltage is applied to the electrolytic capacitor, the diode is turned on, so that the electrolytic capacitor has a reverse polarity. Therefore, the electrolytic capacitor can be prevented from being destroyed.
[0094]
  According to the discharge lamp lighting device of the fifth aspect, even if the average voltage of the AC power supply is lowered by phase control to cause an unbalance between the positive and negative peak values, the short-circuit means is opened by the control means of the hysteresis prevention circuit. By connecting a resistor in series to the smoothing capacitor, the voltage that suppresses the positive / negative asymmetry of the voltage applied to the inverter circuit is suppressed, and the voltage that suppresses the positive / negative asymmetry is supplied to the inverter circuit. By lighting up, flickering of the discharge lamp can be prevented.
[0095]
  According to the discharge lamp lighting device of the sixth aspect, in addition to the discharge lamp lighting device of the fifth aspect, the switching element is controlled according to the voltage of the smoothing capacitor, so that the average voltage of the AC power supply can be handled with a simple configuration. .
[0096]
  According to the discharge lamp lighting device of the seventh aspect, since the resistance is a resistance value capable of suppressing the hysteresis characteristic of the AC power supply, the voltage with suppressed positive / negative asymmetry is supplied to the inverter circuit by connecting in series with the smoothing capacitor. Further, the discharge lamp can be prevented from flickering by lighting the discharge lamp with the inverter circuit.
[0097]
  According to the discharge lamp lighting device according to claim 8, in addition to the discharge lamp lighting device according to claim 7, since the hysteresis characteristic is small when the average voltage is high, a decrease in the resistance value is prevented by reducing the resistance value. Since the hysteresis characteristic is large when the average voltage is low, the hysteresis characteristic can be suppressed by increasing the resistance value.
[0098]
  According to the discharge lamp lighting device of the ninth aspect, in addition to the discharge lamp lighting device of the seventh or eighth aspect, by using a positive temperature coefficient thermistor, when the average voltage is high, the current flowing through the positive temperature coefficient thermistor is not large, so heat is generated. The resistance value is low, and when the average voltage is low, the current flowing through the positive temperature coefficient thermistor increases to generate heat and the resistance value can be high.
[0099]
  According to the discharge lamp lighting device according to claim 10, the luminance of the discharge lamp can be adjusted following the voltage of the AC power source by applying a voltage to the inverter circuit after being partially smoothed by a smoothing circuit at normal times, and the average voltage When the voltage drops below a predetermined value, the smoothing circuit is completely smoothed to supply the inverter circuit with a voltage that suppresses the positive / negative asymmetry generated with respect to the frequency of the AC power supply. Can prevent lamp flicker.
  Claim11According to the described bulb-type fluorescent lamp, claims 1 to10Since the discharge lamp lighting device according to any one of the above and a cover that supports the fluorescent lamp, and a base that is electrically connected to the discharge lamp lighting device and disposed at the base end of the cover, respectively, The effect of can be produced.
[0100]
  Claim12According to the described bulb-type fluorescent lamp, the claim11In addition to the light bulb-type fluorescent lamp described above, the lamp is provided with a glove that accommodates the fluorescent lamp and forms a light bulb shape with the cover, and can be used in place of the light bulb with lower power consumption than the light bulb.
[Brief description of the drawings]
FIG. 1 is a circuit diagram showing a lighting circuit according to an embodiment of the present invention.
FIG. 2 is a side view in which a part of an embodiment of the same bulb-type fluorescent lamp is cut out and a globe is seen through.
FIG. 3 is an explanatory view showing an electric circuit for expanding and showing the bulb of one embodiment of the bulb-type discharge lamp, and lighting the bulb.
FIG. 4 is a plan view through the partition of the arc tube.
FIG. 5 is a waveform diagram showing the operation of a lighting circuit having no hysteresis prevention circuit.
  (A) Input voltage
  (B) Lamp current
6 is a waveform diagram showing the operation of the lighting circuit shown in FIG.
  (A) Input voltage
  (B) Lamp current
  (C) Voltage of electrolytic capacitors C4 and C5
FIG. 7 is a circuit diagram showing a lighting circuit according to another embodiment;
FIG. 8 is a waveform chart showing the operation of the lighting circuit when the hysteresis prevention circuit of FIG. 7 is not operated.
  (A) Input voltage
  (B) Input current
  (C) Lamp current
9 is a waveform diagram showing the operation of the lighting circuit of FIG. 7; FIG.
  (A) Input voltage
  (B) Input current
  (C) Lamp current
FIG. 10 is a circuit diagram showing a lighting circuit according to another embodiment;
[Fig. 11] Same as abovePrerequisite technologyIt is a circuit diagram which shows the lighting circuit.
12 is a waveform diagram showing the operation of the lighting circuit of FIG. 11; FIG.
  (A) Input voltage
  (B) Lamp current when the hysteresis prevention circuit is not operated
  (C) Lamp current
FIG. 13 is a circuit diagram showing a lighting circuit according to another embodiment;
FIG. 14 is a waveform diagram showing the operation of the lighting circuit of FIG. 13;
  (A) Input voltage
  (B) Lamp current when the hysteresis prevention circuit is not operated
  (C) Lamp current
[Explanation of symbols]
        11 Bulb-type fluorescent lamp
        12 base
        14 Cover
        16 Lighting circuit as a discharge lamp lighting device
        17 Globe
        18 Arc tube as a discharge lamp
        72 AC power supply
        73 DC cut timesRoad
        77 Inverter circuit
        81, 82 Hysteresis prevention timesRoad
        84 Smoothing system switching circuit
        C4 and C5 capacitors
        D5, D6 diode
        Q11 Field-effect transistors as switching elements

Claims (12)

A DC cut circuit having a capacitor that can be connected in series only to one of a pair of input lines connected to an AC power supply whose output voltage is variable by phase control;
A rectifier circuit connected to an AC power source through this DC cut circuit;
A smoothing circuit for smoothing the output of the rectifier circuit;
An inverter circuit connected to the smoothing circuit and lighting the discharge lamp;
A discharge lamp lighting device comprising: The discharge lamp lighting device according to claim 1, wherein a plurality of capacitors are connected in series in the DC cut circuit. The discharge lamp lighting device according to claim 2, wherein the capacitors are connected in series with different polarities by electrolytic capacitors. 4. The discharge lamp lighting device according to claim 3, wherein the direct current cut circuit includes a diode connected in parallel to the electrolytic capacitor with a polarity in a direction in which the electrolytic capacitor is turned on when a reverse polarity voltage is applied to the electrolytic capacitor. . A rectifier circuit that can be connected to an AC power source with variable output voltage by phase control;
A smoothing circuit having a smoothing capacitor and smoothing the output of the rectifier circuit;
Hysteresis prevention having a resistor connected in series to the smoothing capacitor, a short-circuit means capable of short-circuiting the resistor, and a control means for opening the short-circuit means and connecting the resistor to the smoothing capacitor in series when the average voltage of the AC power supply decreases With circuit;
An inverter circuit connected to the smoothing circuit and lighting the discharge lamp;
A discharge lamp lighting device comprising: The discharge lamp lighting device according to claim 5, wherein the control means controls the switching element according to a voltage of the smoothing capacitor. A rectifier circuit that can be connected to an AC power source with variable output voltage by phase control;
A smoothing circuit having a smoothing capacitor and smoothing the output of the rectifier circuit;
A hysteresis prevention circuit including a resistor connected in series to the smoothing capacitor and having a resistance value capable of suppressing the hysteresis characteristic of the AC power supply;
An inverter circuit connected to the smoothing circuit and lighting the discharge lamp;
A discharge lamp lighting device comprising: The discharge lamp lighting device according to claim 7, wherein the resistance has a low resistance value when the average voltage of the AC power supply is high and high when the average voltage of the AC power supply is low. The discharge lamp lighting device according to claim 7 or 8, wherein the resistor is a positive temperature coefficient thermistor. A rectifier circuit that can be connected to an AC power source with variable output voltage by phase control;
A smoothing circuit which has a smoothing capacitor and can be switched to full smoothing to smooth the output of the rectifier circuit;
A smoothing mode switching circuit that switches the smoothing circuit to full smoothing when the average voltage of the AC power supply decreases;
An inverter circuit connected to the smoothing circuit and lighting the discharge lamp;
The discharge lamp lighting apparatus characterized by comprising a. With fluorescent lamps;
A discharge lamp lighting device according to any one of claims 1 to 10 ;
A cover for housing the discharge lamp lighting device and supporting the fluorescent lamp;
A base connected to the discharge lamp lighting device and disposed at the base end of the cover;
A bulb-type fluorescent lamp characterized by comprising: The bulb-type fluorescent lamp according to claim 11 , further comprising a globe that houses the fluorescent lamp and forms a substantially bulb shape with the cover.

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