JP2005166288A

JP2005166288A - Discharge lamp lighting device

Info

Publication number: JP2005166288A
Application number: JP2003399862A
Authority: JP
Inventors: Osamu Takahashi; 修高橋; Yasunori Yashiro; 康則家城
Original assignee: Mitsubishi Electric Corp; Mitsubishi Electric Lighting Corp
Current assignee: Mitsubishi Electric Corp; Mitsubishi Electric Lighting Corp
Priority date: 2003-11-28
Filing date: 2003-11-28
Publication date: 2005-06-23
Also published as: CN1622734A; TWI288581B; CN100525573C; TW200518635A

Abstract

<P>PROBLEM TO BE SOLVED: To provide a discharge lamp lighting device, of which an inverter circuit can oscillate only when a discharge lamp is mounted on it. <P>SOLUTION: The discharge lamp lighting device is provided with an inverter circuit converting a direct current supplied from a direct current power source 1 into a high-frequency current, an inverter drive circuit 38 driving the inverter circuit, a discharge lamp load circuit L10 consisting of choke coils 5, 10, a series circuit of a coupling capacitor 9 connected to the choke coils 5, 10 through discharge lamps 6, 11, and capacitors 7, 12 connected in parallel with the discharge lamps 6, 11, a start-up voltage supply circuit VS supplying voltage for oscillating and starting up the inverter drive circuit 38 based on a current flowing in the coupling capacitor 9, and a high frequency voltage supply circuit FS supplying the inverter drive circuit 38 with a high frequency voltage generated based on a high frequency current output of either of switching elements 2, 3. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

この発明は、放電灯点灯装置に係り、特に、放電灯が装着された場合にのみ始動できるようにし、また、放電灯の寿命末期等で保護回路が作動し、装置を停止・保持した後、電源を遮断することなく不良放電灯を器具から抜去し、正常放電灯を装着すると再始動を開始するようにした放電灯点灯装置に関するものである。 The present invention relates to a discharge lamp lighting device, in particular, it can be started only when the discharge lamp is mounted, and after the protection circuit is activated at the end of the life of the discharge lamp and the device is stopped and held, The present invention relates to a discharge lamp lighting device in which a defective discharge lamp is removed from an appliance without shutting off a power source and restart is started when a normal discharge lamp is attached.

直列に接続した２つのスイッチング素子の発振動作により放電灯に交流電力を供給するインバータ手段と、前記インバータ手段の出力に接続した共振用コンデンサ、直流カットコンデンサ及び放電灯からなる負荷部と、前記直流カットコンデンサの両端電圧により放電灯の負荷状態を検出する負荷検出手段と、前記負荷検出手段の検出結果に応じて放電灯の寿命を判別する寿命判別手段と寿命判別手段（負荷判別手段）の判別結果に応じて前記インバータ手段のスイッチング素子の発振動作を制御する発振制御手段と、前記直流カットコンデンサから電源を確保する制御電源部とを備えている（例えば特許文献１）。 Inverter means for supplying AC power to the discharge lamp by the oscillation operation of two switching elements connected in series, a load section comprising a resonance capacitor, a DC cut capacitor and a discharge lamp connected to the output of the inverter means, and the DC Discrimination between load detection means for detecting the load state of the discharge lamp based on the voltage across the cut capacitor, life determination means for determining the life of the discharge lamp according to the detection result of the load detection means, and life determination means (load determination means) An oscillation control means for controlling the oscillation operation of the switching element of the inverter means according to the result, and a control power supply unit for securing a power supply from the DC cut capacitor are provided (for example, Patent Document 1).

特開２００１−３３８７９１（５頁の６行目〜１０頁の４３行目、図１〜図６）JP 2001-338791 (page 6, line 6 to page 10, line 43, FIGS. 1 to 6)

従来の放電灯点灯装置において、直流電源の投入時、発振制御手段の駆動電源は抵抗、電源監視部のＯＮ状態にあるスイッチを介して供給される。発振制御手段の駆動電源電圧が図５に示すＫ１１以上に達すればドライバーＩＣは動作を開始する。
また、駆動電源電圧がＫ１２以下になれば、動作を停止する。しかし、この方式では放電灯が点灯装置に装着されていない場合でも直流電源が投入されれば、無条件でインバータ手段を発振駆動させるため本来不要な動作を引き起こす問題があった。そのため、図５及び図６に示すように電源監視部で制御電圧を監視しながらインバータ手段の発振及び停止を繰り返して正常放電灯が装着されるのを待つという方式にする必要があり、このため点灯装置が複雑、高価で大型になる問題があった。 In the conventional discharge lamp lighting device, when the DC power supply is turned on, the drive power for the oscillation control means is supplied through the resistor and the switch in the ON state of the power supply monitoring unit. When the drive power supply voltage of the oscillation control means reaches K11 or more shown in FIG. 5, the driver IC starts operation.
When the drive power supply voltage becomes K12 or less, the operation is stopped. However, in this system, even if the discharge lamp is not attached to the lighting device, there is a problem that if the DC power is turned on, the inverter means is driven to oscillate unconditionally, causing an originally unnecessary operation. For this reason, as shown in FIGS. 5 and 6, it is necessary to repeat the oscillation and stop of the inverter means while monitoring the control voltage by the power supply monitoring unit and wait for the normal discharge lamp to be mounted. There is a problem that the lighting device is complicated, expensive and large.

この発明は、従来装置の上記のような問題点を解決するためになされたもので、この発明の第１目的は放電灯が装着されている場合にのみインバータ回路の発振が可能なようにした安価で小型の放電灯点灯装置を提供することを目的とする。 The present invention has been made to solve the above-described problems of the conventional apparatus. The first object of the present invention is to enable the oscillation of the inverter circuit only when the discharge lamp is mounted. An object is to provide an inexpensive and small discharge lamp lighting device.

また、この発明の第２の目的は装着されている放電灯が寿命末期等の不具合理由で不良になればインバータ回路を停止・保持するとともに、直流電源を投入継続したままで上記不良放電灯を抜去した後、正常放電灯を装着するとインバータ回路が再始動を開始する安価で小型の放電灯点灯装置を提供することを目的とする。 The second object of the present invention is to stop and hold the inverter circuit if the mounted discharge lamp becomes defective due to a malfunction such as the end of its life, and to remove the defective discharge lamp while keeping the DC power on. An object of the present invention is to provide an inexpensive and small discharge lamp lighting device in which an inverter circuit starts restarting when a normal discharge lamp is mounted after being removed.

また、この発明の第３の目的は直流電源投入時及びインバータ回路が保護動作で停止・保持後に不良放電灯を正常放電灯に置換して、インバータ回路が始動する際に、放電灯のコールドスタートが防止可能な安価で小型の放電灯点灯装置を提供することを目的とする。 A third object of the present invention is to cold start the discharge lamp when the DC circuit is turned on and when the inverter circuit starts after the defective discharge lamp is replaced with a normal discharge lamp after the inverter circuit is stopped and held in a protective operation. An object of the present invention is to provide an inexpensive and small discharge lamp lighting device capable of preventing the above.

この発明に係る放電灯点灯装置は、直流電源と、この直流電源から供給される直流を高周波電流に変換する２つのスイッチング素子を有するハーフブリッジ回路からなるインバータ回路と、このインバータ回路を駆動するインバータ駆動回路と、チョークコイル、このチョークコイルに放電灯を介して接続されたカップリングコンデンサの直列回路、上記放電灯に並列に接続されたコンデンサから成る放電灯負荷回路と、上記カップリングコンデンサに流れる電流に基づいて上記インバータ駆動回路を発振起動させる電圧を供給する起動電圧供給回路と、上記スイッチング素子のいずれか一方の高周波電流出力に基づいて発生した高周波電圧を上記インバータ駆動回路に供給する高周波電圧供給回路と、を備えたものである。 A discharge lamp lighting device according to the present invention includes a DC power supply, an inverter circuit including a half bridge circuit having two switching elements that convert a DC supplied from the DC power supply into a high-frequency current, and an inverter that drives the inverter circuit A drive circuit, a choke coil, a series circuit of a coupling capacitor connected to the choke coil via a discharge lamp, a discharge lamp load circuit composed of a capacitor connected in parallel to the discharge lamp, and the coupling capacitor A start-up voltage supply circuit for supplying a voltage for starting the oscillation of the inverter drive circuit based on a current; and a high-frequency voltage for supplying a high-frequency voltage generated on the basis of a high-frequency current output of any one of the switching elements to the inverter drive circuit And a supply circuit.

この発明に係る放電灯点灯装置は、直流電源と、この直流電源から供給される直流を高周波電流に変換する２つのスイッチング素子を有するハーフブリッジ回路からなるインバータ回路と、このインバータ回路を駆動するインバータ駆動回路と、チョークコイル、このチョークコイルに放電灯を介して接続されたカップリングコンデンサの直列回路、上記放電灯に並列に接続されたコンデンサから成る放電灯負荷回路と、上記カップリングコンデンサに流れる電流に基づいて上記インバータ駆動回路を発振起動させる電圧を供給する起動電圧供給回路と、上記スイッチング素子のいずれか一方の高周波電流出力に基づいて発生した高周波電圧を上記インバータ駆動回路に供給する高周波電圧供給回路と、を備えたので、放電灯が装着されている場合にのみインバータ回路の発振を可能にすることができる。 A discharge lamp lighting device according to the present invention includes a DC power supply, an inverter circuit including a half bridge circuit having two switching elements that convert a DC supplied from the DC power supply into a high-frequency current, and an inverter that drives the inverter circuit A drive circuit, a choke coil, a series circuit of a coupling capacitor connected to the choke coil via a discharge lamp, a discharge lamp load circuit composed of a capacitor connected in parallel to the discharge lamp, and the coupling capacitor A start-up voltage supply circuit for supplying a voltage for starting the oscillation of the inverter drive circuit based on a current; and a high-frequency voltage for supplying a high-frequency voltage generated on the basis of a high-frequency current output of any one of the switching elements to the inverter drive circuit Supply circuit, so that the discharge lamp is installed Only it may allow the oscillation of the inverter circuit when.

実施の形態１．
図１は、この発明の実施の形態を示す放電灯点灯装置の回路図、図２は放電灯点灯装置の動作説明図である。図１において、直流電源１は、例えば、商用電源をダイオードブリッジで整流後電解コンデンサで平滑して得られる。スイッチング素子２、３はＭＯＳＦＥＴが使用され、スイッチング素子２、３の直列回路は直流電源１に接続されインバータ回路を構成する。抵抗１４はＭＯＳＦＥＴ２と並列に接続される。
放電灯負荷回路Ｌ１０（一点鎖線で示す）において、チョークコイル５、放電灯６、カップリングコンデンサ９は直列に接続され、これらの直列回路はスイッチング素子３に並列に接続される。放電灯６にはコンデンサ７及び抵抗８が並列に接続される。チョークコイル５と放電灯６の直列回路に並列にチョークコイル１０と放電灯１１の直列回路が並列に接続される。放電灯１１にはコンデンサ１２及び抵抗１３が並列に接続される。 Embodiment 1 FIG.
FIG. 1 is a circuit diagram of a discharge lamp lighting device showing an embodiment of the present invention, and FIG. 2 is an operation explanatory diagram of the discharge lamp lighting device. In FIG. 1, a DC power source 1 is obtained, for example, by rectifying a commercial power source with a diode bridge and then smoothing it with an electrolytic capacitor. MOSFETs are used for the switching elements 2 and 3, and a series circuit of the switching elements 2 and 3 is connected to the DC power source 1 to constitute an inverter circuit. The resistor 14 is connected in parallel with the MOSFET 2.
In the discharge lamp load circuit L10 (indicated by the alternate long and short dash line), the choke coil 5, the discharge lamp 6, and the coupling capacitor 9 are connected in series, and these series circuits are connected in parallel to the switching element 3. A capacitor 7 and a resistor 8 are connected to the discharge lamp 6 in parallel. A series circuit of the choke coil 10 and the discharge lamp 11 is connected in parallel to the series circuit of the choke coil 5 and the discharge lamp 6. A capacitor 12 and a resistor 13 are connected to the discharge lamp 11 in parallel.

インバータ回路を駆動するインバータ駆動回路３８においては、正の電源端子Ｖｃｃに後述の起動電圧供給回路ＶＳと高周波電圧供給回路ＦＳの出力が接続され、負の電源端子ＣＯＭは直流電源１の負極に接続される。そして、スイッチング素子２、３のゲート及びスイッチング素子２のソースとスイッチング素子３のドレインの接続点にこれらのスイッチング素子を交互にＯＮ、ＯＦＦするように駆動出力が接続される。
抵抗３７、コンデンサ３６はインバータ駆動回路３８の発振周波数を定める回路要素であり、コンデンサ３６は発振コンデンサ接続端子ＣＴと直流電源Ｅの負極の間に接続され、抵抗３７は発振抵抗接続端子ＲＴと発振コンデンサ接続端子ＣＴの間に接続される。 In the inverter drive circuit 38 for driving the inverter circuit, the output of a starting voltage supply circuit VS and a high-frequency voltage supply circuit FS described later are connected to the positive power supply terminal Vcc, and the negative power supply terminal COM is connected to the negative electrode of the DC power supply 1. Is done. A drive output is connected to the connection points of the gates of the switching elements 2 and 3 and the source of the switching element 2 and the drain of the switching element 3 so that these switching elements are alternately turned on and off.
The resistor 37 and the capacitor 36 are circuit elements that determine the oscillation frequency of the inverter drive circuit 38. The capacitor 36 is connected between the oscillation capacitor connection terminal CT and the negative electrode of the DC power supply E, and the resistor 37 oscillates with the oscillation resistance connection terminal RT. It is connected between the capacitor connection terminals CT.

カップリングコンデンサ９に流れる電流に基づいてインバータ駆動回路３８を発振起動させる電圧を供給する起動電圧供給回路ＶＳ（一点鎖線で示す）においては、抵抗１８及び抵抗１９は直列に接続され、カップリングコンデンサ９に並列に接続される。抵抗１８と抵抗１９の接続点にダイオード２０のアノードが接続される。ダイオード２０のカソードはコンデンサ２１を介して直流電源１の負極に接続される。抵抗２２はコンデンサ２１と並列に接続される。ダイオード２０のカソードから抵抗３１、ダイオード３２のアノード、ダイオード３２のカソードを介してインバータ駆動回路３８の正の電源端子Ｖｃｃに接続される。そして、インバータ駆動回路３８の正の電源端子Ｖｃｃと直流電源１の負極間にコンデンサ３３が接続される。 In an activation voltage supply circuit VS (indicated by a one-dot chain line) that supplies a voltage for oscillating and activating the inverter drive circuit 38 based on the current flowing through the coupling capacitor 9, the resistor 18 and the resistor 19 are connected in series, and the coupling capacitor 9 are connected in parallel. The anode of the diode 20 is connected to the connection point between the resistor 18 and the resistor 19. The cathode of the diode 20 is connected to the negative electrode of the DC power supply 1 through the capacitor 21. The resistor 22 is connected in parallel with the capacitor 21. The cathode of the diode 20 is connected to the positive power supply terminal Vcc of the inverter drive circuit 38 through the resistor 31, the anode of the diode 32, and the cathode of the diode 32. A capacitor 33 is connected between the positive power supply terminal Vcc of the inverter drive circuit 38 and the negative electrode of the DC power supply 1.

スイッチング素子のいずれか一方の高周波電流出力に基づいて発生した高周波電圧をインバータ駆動回路３８に供給する高周波電圧供給回路ＦＳは、スイッチング素子３に並列に接続されたコンデンサ１５、抵抗１６及びダイオード１７の直列回路と、アノードが抵抗１６とダイオード１７の接続点に接続され、カソードがインバータ駆動回路３８の正の電源端子Ｖｃｃに接続されたダイオード３５と、カソードがインバータ駆動回路３８の正の電源端子Ｖｃｃに、アノードが直流電源Ｅの負極に接続されたツェナーダイオード３４から構成される。
なお、スイッチング素子２及び３のドレイン・ソース間に並列に内蔵されている等価ダイオードは図示を省略している。 A high-frequency voltage supply circuit FS that supplies a high-frequency voltage generated based on the high-frequency current output of any one of the switching elements to the inverter drive circuit 38 includes a capacitor 15, a resistor 16, and a diode 17 connected in parallel to the switching element 3. A series circuit, a diode 35 whose anode is connected to the connection point of the resistor 16 and the diode 17, a cathode is connected to the positive power supply terminal Vcc of the inverter drive circuit 38, and a cathode is the positive power supply terminal Vcc of the inverter drive circuit 38 The zener diode 34 has an anode connected to the negative electrode of the DC power supply E.
The equivalent diode built in parallel between the drain and source of the switching elements 2 and 3 is not shown.

以下、この発明の実施の形態１を示す放電灯点灯装置の動作を図１、図２により説明する。図１及び図２において、時間ｔ１で直流電源１が投入されると、直流電源１から抵抗１４、チョークコイル５、放電灯６の一方のフィラメント、抵抗８、放電灯６の他方のフィラメントを介してカップリングコンデンサ９は充電される。また、直流電源１からチョークコイル１０、放電灯１１の一方のフィラメント、抵抗１３、放電灯１１の他方のフィラメントを介しても同様にカップリングコンデンサ９は充電される。 Hereinafter, the operation of the discharge lamp lighting device according to Embodiment 1 of the present invention will be described with reference to FIGS. 1 and 2, when the DC power source 1 is turned on at time t1, the DC power source 1 passes through the resistor 14, the choke coil 5, one filament of the discharge lamp 6, the resistor 8, and the other filament of the discharge lamp 6. Thus, the coupling capacitor 9 is charged. Similarly, the coupling capacitor 9 is charged from the DC power source 1 through the choke coil 10, one filament of the discharge lamp 11, the resistor 13, and the other filament of the discharge lamp 11.

カップリングコンデンサ９に充電された電圧は、起動電圧供給回路ＶＳの抵抗１８、抵抗１９で分圧されダイオード２０を介して整流されコンデンサ２１を充電するとともに抵抗３１、ダイオード３２を介してインバータ駆動回路３８の正の電源端子Ｖｃｃに接続されているコンデンサ３３を充電する。 The voltage charged in the coupling capacitor 9 is divided by the resistors 18 and 19 of the starting voltage supply circuit VS and rectified through the diode 20 to charge the capacitor 21, and the inverter drive circuit through the resistor 31 and the diode 32. The capacitor 33 connected to the 38 positive power supply terminals Vcc is charged.

インバータ駆動回路３８の正の電源端子Ｖｃｃの電圧が発振可能な電圧レベルＶ３８Ｈまで上昇するとインバータ駆動回路３８は点灯周波数ｆｏｐで発振開始し、直流電源１からインバータ回路を介して高周波電流が放電灯負荷回路Ｌ１０に供給される。高周波電流が放電灯負荷回路Ｌ１０に供給されればダイオード１７のカソードにはインバータ回路の発振周波数に同期した高周波矩形波電圧が発生する（図２（ｃ１））。この高周波矩形波電圧は高周波電源供給回路ＦＳにおいて、スイッチング素子３に並列に接続されたコンデンサ１５、抵抗１６及びダイオード１７の直列回路から得られる高周波電圧をダイオード３５を介してインバータ駆動回路３８の正の電源端子Ｖｃｃに供給されるため、正の電源端子Ｖｃｃ電圧はツェナーダイオード３４で定められる電圧Ｖ３４まで上昇（図２（ｂ）のｔ２〜ｔ３期間）した後一定電圧となる。 When the voltage of the positive power supply terminal Vcc of the inverter drive circuit 38 rises to the oscillating voltage level V38H, the inverter drive circuit 38 starts oscillating at the lighting frequency fp, and the high frequency current is discharged from the DC power supply 1 through the inverter circuit to the discharge lamp load. It is supplied to the circuit L10. When a high-frequency current is supplied to the discharge lamp load circuit L10, a high-frequency rectangular wave voltage synchronized with the oscillation frequency of the inverter circuit is generated at the cathode of the diode 17 (FIG. 2 (c1)). This high-frequency rectangular wave voltage is obtained by applying a high-frequency voltage obtained from the series circuit of the capacitor 15, the resistor 16 and the diode 17 connected in parallel to the switching element 3 in the high-frequency power supply circuit FS via the diode 35. Therefore, the positive power supply terminal Vcc voltage rises to the voltage V34 determined by the Zener diode 34 (period t2 to t3 in FIG. 2B) and becomes a constant voltage.

以降、インバータ駆動回路３８の正の電源端子Ｖｃｃには主としてダイオード１７のカソード端子から高周波矩形波電圧が継続して印加され続けているので、放電灯負荷回路Ｌ１０の放電灯６及び放電灯１１は点灯し、その後放電状態を継続することができる。 Thereafter, since the high frequency rectangular wave voltage is continuously applied to the positive power supply terminal Vcc of the inverter drive circuit 38 mainly from the cathode terminal of the diode 17, the discharge lamp 6 and the discharge lamp 11 of the discharge lamp load circuit L10 are It is lit and then the discharge state can be continued.

このように、直流電源１を投入後インバータ回路が起動発振するためには、放電灯負荷回路Ｌ１０を構成する放電灯６、１１の内、少なくても１本の放電灯が装着されており、そのフィラメントを介して直流電源１からカップリングコンデンサ９に充電電流が流れる必要がある。
即ち、本点灯装置は、少なくても１本の放電灯が装着されている場合にのみ起動発振が可能なので放電灯が装着されていない状態でのインバータ回路の不要な発振を防止することができる。 Thus, in order for the inverter circuit to start oscillation after the DC power source 1 is turned on, at least one discharge lamp is mounted among the discharge lamps 6 and 11 constituting the discharge lamp load circuit L10. A charging current needs to flow from the DC power supply 1 to the coupling capacitor 9 via the filament.
In other words, the present lighting device can start oscillation only when at least one discharge lamp is mounted, so that it is possible to prevent unnecessary oscillation of the inverter circuit when the discharge lamp is not mounted. .

以上のように、本発明の実施の形態１によればカップリングコンデンサ９に流れる電流に基づいてインバータ駆動回路３８を発振起動させる電圧を供給する起動電圧供給回路ＶＳと、スイッチング素子２、３のいずれか一方の高周波電流出力に基づいて発生した高周波電圧をインバータ駆動回路３８に供給する高周波電圧供給回路ＦＳと、を備えたので、放電灯負荷回路Ｌ１０に放電灯６、１１が装着されている場合にのみインバータ回路の起動発振が可能で安価で小型にすることができる。 As described above, according to the first embodiment of the present invention, the start-up voltage supply circuit VS for supplying a voltage for starting the oscillation of the inverter drive circuit 38 based on the current flowing through the coupling capacitor 9, and the switching elements 2, 3 A high-frequency voltage supply circuit FS for supplying a high-frequency voltage generated on the basis of either one of the high-frequency current outputs to the inverter drive circuit 38, so that the discharge lamps 6 and 11 are mounted on the discharge lamp load circuit L10. Only in this case, the inverter circuit can be started and oscillated, and can be made inexpensive and small.

なお、図１の放電灯負荷回路Ｌ１０では２本の放電灯６、１１が装着されている場合について説明したが、放電灯が１本の場合及び３本以上の場合でもよい。また、放電灯が正常点灯継続時のコンデンサ２１の電圧を、下記の（１）式のように選定すればダイオード３２は逆バイアスされるので電流はゼロとなる。
即ち、放電灯の正常点灯継続時に抵抗１４、抵抗８、抵抗１３、抵抗１８、抵抗１９へ流れる電流を小さくできるので、これらの抵抗の電力損失を低減できる効果がある。
Ｖ３８Ｈ＜Ｖ２１−Ｖ３２Ｆ＜Ｖ３４ … （１）
ただし、上記（１）式の記号は以下を示す。
Ｖ３８Ｈ：インバータ駆動回路が発振を開始する正の電源端子Ｖｃｃ電圧
Ｖ２１：放電灯が正常放電継続時のコンデンサ２１の電圧
Ｖ３２Ｆ：ダイオード３２の順方向降下電圧
Ｖ３４：ツェナーダイオード３４のツェナー電圧
また、直流電源１を投入時、抵抗１４、コンデンサ７、コンデンサ１２の経路でもカップリングコンデンサ９に充電電流が流れて、その結果コンデンサ２１の電圧も上昇するので、抵抗１４、コンデンサ７、コンデンサ１２、カップリングコンデンサ９を適当に選定すれば、抵抗８及び抵抗１３を削除しても上記（１）式を満足させることができ、更に、部品点数の削減と電力損失を低減できる効果がある。 In addition, although the case where the two discharge lamps 6 and 11 are mounted was described in the discharge lamp load circuit L10 of FIG. 1, the case where there is one discharge lamp or three or more discharge lamps may be used. Further, if the voltage of the capacitor 21 when the discharge lamp continues to be normally operated is selected as shown in the following equation (1), the diode 32 is reverse-biased, so that the current becomes zero.
That is, since the current flowing through the resistor 14, the resistor 8, the resistor 13, the resistor 18, and the resistor 19 can be reduced when the discharge lamp is normally lit, the power loss of these resistors can be reduced.
V38H <V21-V32F <V34 (1)
However, the symbols in the above formula (1) indicate the following.
V38H: Positive power supply terminal Vcc voltage at which the inverter drive circuit starts oscillating V21: Voltage of capacitor 21 when the discharge lamp continues normal discharge V32F: Forward voltage drop of diode 32 V34: Zener voltage of zener diode 34 When the power source 1 is turned on, a charging current flows through the coupling capacitor 9 also in the path of the resistor 14, the capacitor 7, and the capacitor 12, and as a result, the voltage of the capacitor 21 also rises. Therefore, the resistor 14, the capacitor 7, the capacitor 12, and the coupling If the capacitor 9 is appropriately selected, the above equation (1) can be satisfied even if the resistor 8 and the resistor 13 are omitted, and there is an effect that the number of parts can be reduced and the power loss can be reduced.

実施の形態２．
実施の形態１では、放電灯６、１１に対応して共用のカップリングコンデンサ９を設けたが、本実施の形態は放電灯６、１１に対応してカップリングコンデンサ９ａ、９ｂを個別に設けたものである。
図３は、この発明の実施の形態２を示す放電灯点灯装置の回路図である。
図において、実施の形態１を示す図１と同一又は相当する回路及び部品には同一の記号及び名称を付し説明を省略する。図３において、放電灯負荷回路Ｌ２０はチョークコイル５、放電灯６、カップリングコンデンサ９ａ、放電灯６に並列に接続されたコンデンサ７及び抵抗８から構成される。また、放電灯負荷回路Ｌ３０はチョークコイル１０、放電灯１１、カップリングコンデンサ９ｂ、放電灯１１に並列に接続されたコンデンサ１２及び抵抗１３から構成される。 Embodiment 2. FIG.
In the first embodiment, the common coupling capacitor 9 is provided corresponding to the discharge lamps 6 and 11, but in the present embodiment, the coupling capacitors 9a and 9b are provided individually corresponding to the discharge lamps 6 and 11, respectively. It is a thing.
FIG. 3 is a circuit diagram of a discharge lamp lighting device showing Embodiment 2 of the present invention.
In the figure, the same symbols and names are assigned to the same and corresponding circuits and components as those in FIG. In FIG. 3, the discharge lamp load circuit L20 includes a choke coil 5, a discharge lamp 6, a coupling capacitor 9a, a capacitor 7 connected in parallel to the discharge lamp 6, and a resistor 8. The discharge lamp load circuit L30 includes a choke coil 10, a discharge lamp 11, a coupling capacitor 9b, a capacitor 12 connected in parallel to the discharge lamp 11, and a resistor 13.

起動電圧供給回路ＶＳ１において、抵抗１８ａ、抵抗１９ａは直列に接続されカップリングコンデンサ９ａに並列に接続される。ダイオード２０ａのアノードは抵抗１８ａと１９ａの接続点に接続され、カソードはコンデンサ２１に接続される。また、抵抗１８ｂ、抵抗１９ｂは直列に接続されカップリングコンデンサ９ｂに並列に接続される。ダイオード２０ｂのアノードは抵抗１８ｂと１９ｂの接続点に接続され、カソードはダイオード２０ａのカソードに接続される。また、抵抗２２、抵抗３１、ダイオード３２、コンデンサ３３は実施の形態１の図１と同様に接続される。 In the starting voltage supply circuit VS1, the resistor 18a and the resistor 19a are connected in series and are connected in parallel to the coupling capacitor 9a. The anode of the diode 20 a is connected to the connection point between the resistors 18 a and 19 a, and the cathode is connected to the capacitor 21. The resistors 18b and 19b are connected in series and connected in parallel to the coupling capacitor 9b. The anode of the diode 20b is connected to the connection point between the resistors 18b and 19b, and the cathode is connected to the cathode of the diode 20a. Further, the resistor 22, the resistor 31, the diode 32, and the capacitor 33 are connected in the same manner as in FIG. 1 of the first embodiment.

以下、この発明の実施の形態２を示す放電灯点灯装置の動作を図１〜３により説明する。なお、インバータ駆動回路が起動・発振した後の動作は実施の形態１の場合と同一なので説明を省略し、インバータ駆動回路３８が起動・発振するまでを説明する。
実施の形態１の図１において、放電灯が正常点灯を継続している場合のカップリングコンデンサ９の電圧の平均値は直流電源１の電圧をＶ１とすればその電圧はＶ１／２である。しかし、その瞬時値は放電灯及び放電灯に並列に接続されたコンデンサからの発振動作に伴う電流の流入及び流出によりＶ１／２を中心に変動する。カップリングコンデンサ９の静電容量値が同一なら、放電灯数を増加すればそれに比例してカップリングコンデンサ９の電圧の変動幅も増大するので、放電灯数を増加する場合にはカップリングコンデンサ９の静電容量値を増加する必要がある。 Hereinafter, the operation of the discharge lamp lighting device according to Embodiment 2 of the present invention will be described with reference to FIGS. Since the operation after the inverter drive circuit is activated and oscillated is the same as that in the first embodiment, the description thereof will be omitted, and the operation until the inverter drive circuit 38 is activated and oscillated will be described.
In FIG. 1 of the first embodiment, the average value of the voltage of the coupling capacitor 9 when the discharge lamp is normally lit is V1 / 2 if the voltage of the DC power supply 1 is V1. However, the instantaneous value fluctuates around V1 / 2 due to the inflow and outflow of current accompanying the oscillation operation from the discharge lamp and the capacitor connected in parallel to the discharge lamp. If the capacitance value of the coupling capacitor 9 is the same, if the number of discharge lamps is increased, the fluctuation range of the voltage of the coupling capacitor 9 is increased in proportion to that. Therefore, when the number of discharge lamps is increased, the coupling capacitor is increased. It is necessary to increase the capacitance value of 9.

しかし、カップリングコンデンサ９の静電容量値を増加すると直流電源１を投入してからインバータ回路が発振するまでの時間が長くなる。（図２のｔ１からｔ２の時間が長くなる）この時間を短縮するには、抵抗１４、抵抗８、抵抗１３の抵抗値を小さくすれば可能であるが、これらの抵抗の電力損失が増加してしまう。 However, when the capacitance value of the coupling capacitor 9 is increased, the time from when the DC power source 1 is turned on until the inverter circuit oscillates becomes longer. (The time from t1 to t2 in FIG. 2 becomes longer) To shorten this time, it is possible to reduce the resistance values of the resistors 14, 8 and 13, but the power loss of these resistors increases. End up.

この発明の実施の形態２の図３の構成においては、放電灯６、１１に対応してカップリングコンデンサ９ａ、９ｂを個別に設けているのでカップリングコンデンサ９ａ、９ｂの静電容量値を小さく設定でき、そのため直流電源１の投入からインバータ駆動回路３８が発振するまでの時間（ｔ１からｔ２に至る時間）を短くすることができる。 In the configuration of FIG. 3 according to the second embodiment of the present invention, since the coupling capacitors 9a and 9b are individually provided corresponding to the discharge lamps 6 and 11, the capacitance values of the coupling capacitors 9a and 9b are reduced. Therefore, the time from when the DC power source 1 is turned on until the inverter drive circuit 38 oscillates (the time from t1 to t2) can be shortened.

以上のように、各放電灯負荷回路Ｌ２０、Ｌ３０の各カップリングコンデンサ９ａ、９ｂに流れる電流に基づいてインバータ駆動回路を発振起動させる電圧を供給する起動電圧供給回路ＶＳと、スイッチング素子２、３のいずれか一方の高周波電流出力に基づいて発生した高周波電圧を上記インバータ駆動回路に供給する高周波電圧供給回路ＦＳと、を備えたので、カップリングコンデンサ９ａ、９ｂの静電容量値を小さく設定でき、直流電源１の投入からインバータ駆動回路３８が発振するまでの時間を短くすることができる。
また、抵抗１４、抵抗８、抵抗１３の抵抗値を大きく選定できるのでその電力損失を小さくすることができる。 As described above, the start-up voltage supply circuit VS for supplying the voltage for starting the oscillation of the inverter drive circuit based on the currents flowing through the coupling capacitors 9a and 9b of the discharge lamp load circuits L20 and L30, and the switching elements 2, 3 And a high-frequency voltage supply circuit FS that supplies a high-frequency voltage generated based on any one of the high-frequency current outputs to the inverter drive circuit, so that the capacitance values of the coupling capacitors 9a and 9b can be set small. The time from when the DC power source 1 is turned on until the inverter drive circuit 38 oscillates can be shortened.
Further, since the resistance values of the resistor 14, the resistor 8, and the resistor 13 can be selected large, the power loss can be reduced.

なお、本実施の形態では放電灯が２灯の場合を示したが、これが１灯あるいは３灯以上の場合でもよい。 In the present embodiment, the case where there are two discharge lamps is shown, but this may be one lamp or three or more lamps.

実施の形態３．
図４は、この発明の実施の形態３を示す放電灯点灯装置の回路図、図５は放電灯点灯装置の動作説明図である。
本実施の形態は実施の形態１に予熱タイマー回路を備えたものである。
図４において、実施の形態１と同一又は相当する回路及び部品には同一の記号及び名称を付し説明を省略する。予熱タイマー回路ＴＰＨ１０（一点鎖線で示す）において、抵抗４１はその一端がインバータ回路の正の電源端子Ｖｃｃに、他端が電解コンデンサ４２を介して直流電源１の負極に接続される。なお、抵抗４１と電解コンデンサ４２は積分回路である。
抵抗４３と抵抗４４の直列回路が電解コンデンサ４２に並列に接続される。抵抗４３と抵抗４４の接続点はトランジスタ４５のベースに接続される。トランジスタ４５のエミッタは直流電源１の負極に接続される。トランジスタ４５のコレクタからコンデンサ４６を介して抵抗３７とコンデンサ３６の接続点に接続される。 Embodiment 3 FIG.
FIG. 4 is a circuit diagram of a discharge lamp lighting device showing Embodiment 3 of the present invention, and FIG. 5 is an operation explanatory diagram of the discharge lamp lighting device.
In this embodiment, a preheating timer circuit is provided in the first embodiment.
In FIG. 4, the same symbols and names are assigned to circuits and components that are the same as or equivalent to those in the first embodiment, and description thereof is omitted. In the preheating timer circuit TPH10 (indicated by a one-dot chain line), one end of the resistor 41 is connected to the positive power supply terminal Vcc of the inverter circuit, and the other end is connected to the negative electrode of the DC power supply 1 through the electrolytic capacitor 42. The resistor 41 and the electrolytic capacitor 42 are an integration circuit.
A series circuit of a resistor 43 and a resistor 44 is connected to the electrolytic capacitor 42 in parallel. A connection point between the resistors 43 and 44 is connected to the base of the transistor 45. The emitter of the transistor 45 is connected to the negative electrode of the DC power supply 1. The collector of the transistor 45 is connected to the connection point of the resistor 37 and the capacitor 36 via the capacitor 46.

以下、この発明の実施の形態３を示す放電灯点灯装置の動作を図４、図５により説明する。図５（ａ）〜（ｃ１）は実施の形態１の動作を示す図２と同じであり、本実施の形態は図５（ｃ２）、（ｄ１）、（ｅ）が対応し、図５（ｄ２）は後述の実施の形態４対応のものである。 Hereinafter, the operation of the discharge lamp lighting device according to Embodiment 3 of the present invention will be described with reference to FIGS. 5 (a) to (c1) are the same as FIG. 2 showing the operation of the first embodiment, and this embodiment corresponds to FIGS. 5 (c2), (d1), and (e), and FIG. d2) corresponds to Embodiment 4 described later.

なお、トランジスタ４５がＯＦＦ状態でインバータ駆動回路３８の発振周波数を定める抵抗３７とコンデンサ３６のみが接続されている場合の発振周波数を、図５（ｃ２）に示すように放電灯６、１１の正常点灯周波数ｆｏｐより高くし、放電灯６、１１は点灯にいたらずフィラメントに当該放電灯の適正な予熱電流が流れるような周波数ｆｐＨ（ｆｏｐ＜ｆｐＨ）になるように抵抗３７、コンデンサ３６の値を定める。また、トランジスタ４５がＯＮ状態でコンデンサ４６がコンデンサ３６に並列に接続された場合のインバータ駆動回路３８の発振周波数を正常点灯周波数ｆｏｐにするようにコンデンサ４６の値を定めておく。 Note that the oscillation frequency when only the resistor 37 and the capacitor 36 that determine the oscillation frequency of the inverter drive circuit 38 are connected while the transistor 45 is OFF is the normal frequency of the discharge lamps 6 and 11 as shown in FIG. The value of the resistor 37 and the capacitor 36 is set to be higher than the lighting frequency fo so that the discharge lamps 6 and 11 are not lit and the frequency fpH (fop <fpH) is set so that an appropriate preheating current of the discharge lamp flows through the filament. Determine. Further, the value of the capacitor 46 is determined so that the oscillation frequency of the inverter drive circuit 38 when the transistor 45 is ON and the capacitor 46 is connected in parallel to the capacitor 36 is set to the normal lighting frequency fp.

時間ｔ１で直流電源１が投入されるとインバータ駆動回路３８の正の電源端子Ｖｃｃに電圧が印加され、時間ｔ２で起動・発振することは図１で説明した実施の形態１と同様である。この時の発振周波数は上記で説明のように放電灯のフィラメントに適正な予熱電流が流れるｆｐＨである（図５（ｃ２））。また、図５（ｄ１）に示すように、電解コンデンサ４２には抵抗４１を介して充電電流が流れその電圧は上昇していく。電解コンデンサ４２と並列に接続された抵抗４３と抵抗４４の直列回路の接続点の電位がトランジスタ４５のベース・エミッタ間の閾値に達するまではトランジスタ４５はＯＦＦであり（図５（ｅ））、インバータ駆動回路３８は放電灯は点灯に至らずそのフィラメントに適正な予熱電流が流れる発振周波数でインバータ回路を駆動する。 When the DC power supply 1 is turned on at time t1, a voltage is applied to the positive power supply terminal Vcc of the inverter drive circuit 38, and activation and oscillation at time t2 are the same as in the first embodiment described with reference to FIG. The oscillation frequency at this time is fpH at which an appropriate preheating current flows through the filament of the discharge lamp as described above (FIG. 5 (c2)). Further, as shown in FIG. 5D1, a charging current flows through the electrolytic capacitor 42 via the resistor 41, and the voltage increases. The transistor 45 is OFF until the potential at the connection point of the series circuit of the resistor 43 and the resistor 44 connected in parallel with the electrolytic capacitor 42 reaches the threshold between the base and the emitter of the transistor 45 (FIG. 5 (e)). The inverter drive circuit 38 drives the inverter circuit at an oscillation frequency at which an appropriate preheating current flows through the filament without lighting the discharge lamp.

電解コンデンサ４２の電圧がＶ４２まで上昇して時間ｔ４でトランジスタ４５のベース・エミッタ間の電圧がその閾値電圧に達すればトランジスタ４５はＯＮになる（図５（ｅ））。トランジスタ４５がＯＮになればインバータ駆動回路３８の発振周波数は放電灯が正常点灯をするｆｏｐになり、放電灯は予熱状態から正常放電状態になる（図５（ｃ２））。図５より明らかなように時間ｔ２からｔ４の期間が予熱タイマー期間であり、時間ｔ４以降は正常放電期間である。
ここで、抵抗４１及び電解コンデンサ４２の値を適当に定めて予熱タイマー期間を設定して放電灯のコールドスタートを防止する。 When the voltage of the electrolytic capacitor 42 rises to V42 and the voltage between the base and the emitter of the transistor 45 reaches the threshold voltage at time t4, the transistor 45 is turned on (FIG. 5 (e)). When the transistor 45 is turned on, the oscillation frequency of the inverter drive circuit 38 becomes a fo that normally discharges the discharge lamp, and the discharge lamp changes from the preheated state to the normal discharged state (FIG. 5 (c2)). As apparent from FIG. 5, the period from time t2 to t4 is the preheating timer period, and after time t4 is the normal discharge period.
Here, the values of the resistor 41 and the electrolytic capacitor 42 are appropriately determined to set a preheating timer period to prevent the cold start of the discharge lamp.

以上のように、起動電圧供給回路ＶＳの供給電圧を駆動電源として、インバータ回路の発振周波数を正常点灯時の駆動周波数より予め定めた期間大きくし、その後、発振周波数を正常点灯時の駆動周波数に低減する予熱タイマー回路ＴＰＨ１０を備えたので、放電灯６、１１のコールドスタートを防止することができる。 As described above, using the supply voltage of the start-up voltage supply circuit VS as the drive power supply, the oscillation frequency of the inverter circuit is increased from the drive frequency during normal lighting by a predetermined period, and then the oscillation frequency is set to the drive frequency during normal lighting. Since the preheating timer circuit TPH10 to be reduced is provided, the cold start of the discharge lamps 6 and 11 can be prevented.

実施の形態４．
実施の形態３では、予熱タイマー回路の駆動電源を起動電圧供給回路の供給電圧としたが、本実施の形態は高周波電圧供給回路の供給電圧を駆動電源としたものである。
図６は、この発明の実施の形態４を示す放電灯点灯装置の回路図である。図において、実施の形態１乃至３と同一又は相当する回路及び部品には同一の記号及び名称を付し説明を省略する。
予熱タイマー回路ＴＰＨ２０（一点鎖線で示す）は、実施の形態３の図４の予熱タイマー回路ＴＰＨ１０にダイオード４７が付加されたものであり、ダイオード４７のアノードはダイオード３５のアノードに接続される。ダイオード４７のカソードから抵抗４１、電解コンデンサ４２を介して直流電源１の負極に接続される。 Embodiment 4 FIG.
In the third embodiment, the driving power supply for the preheating timer circuit is the supply voltage for the start-up voltage supply circuit, but this embodiment uses the supply voltage for the high-frequency voltage supply circuit as the driving power supply.
FIG. 6 is a circuit diagram of a discharge lamp lighting device showing Embodiment 4 of the present invention. In the figure, the same symbols and names are assigned to circuits and components that are the same as or equivalent to those of the first to third embodiments, and description thereof is omitted.
The preheating timer circuit TPH20 (indicated by a one-dot chain line) is obtained by adding a diode 47 to the preheating timer circuit TPH10 of FIG. 4 of the third embodiment, and the anode of the diode 47 is connected to the anode of the diode 35. The cathode of the diode 47 is connected to the negative electrode of the DC power source 1 through the resistor 41 and the electrolytic capacitor 42.

以下、この発明の実施の形態４を示す放電灯点灯装置の動作を図５、図６により説明する。図５は実施の形態３で示したが図５（ｄ２）（ｅ）が本実施の形態に対応する。 The operation of the discharge lamp lighting device according to Embodiment 4 of the present invention will be described below with reference to FIGS. Although FIG. 5 is shown in the third embodiment, FIGS. 5 (d2) and (e) correspond to this embodiment.

時間ｔ１で直流電源１が投入されるとインバータ駆動回路の正の電源端子Ｖｃｃに電圧が印加され時間ｔ２で起動・発振することは図５で説明した実施の形態３と同様である。しかし、図５（ｄ２）の波形図に示すようにコンデンサ４２への充電は時間ｔ１〜ｔ２の期間は行われず、インバータ駆動回路３８が発振開始する時間ｔ２以降の期間で行われる。時間ｔ４でトランジスタ４５がＯＦＦからＯＮに転ずるように予熱タイマー期間を設定するのは実施の形態３の場合と同一である。
図５（ｄ２）より明らかなように、本実施の形態４によればインバータ駆動回路３８が発振を開始した時間ｔ２を基点にして予熱タイマー回路の動作が開始する。 When the DC power supply 1 is turned on at time t1, a voltage is applied to the positive power supply terminal Vcc of the inverter drive circuit, and start-up and oscillation at time t2 are the same as in the third embodiment described with reference to FIG. However, as shown in the waveform diagram of FIG. 5 (d2), the charging of the capacitor 42 is not performed during the period of time t1 to t2, but is performed during the period after the time t2 when the inverter drive circuit 38 starts oscillation. The preheating timer period is set so that the transistor 45 turns from OFF to ON at time t4, as in the third embodiment.
As apparent from FIG. 5 (d2), according to the fourth embodiment, the operation of the preheating timer circuit starts with the time t2 when the inverter drive circuit 38 starts oscillation as a base point.

以上のように、高周波電圧供給回路ＦＳの供給電圧を駆動電源として、インバータ回路の発振周波数を正常点灯時の駆動周波数より予め定めた期間大きくし、その後、発振周波数を正常点灯時の駆動周波数に低減する予熱タイマ回路ＴＰＨ２０を備えたので、予熱動作をしていない時間ｔ１〜ｔ２の時間の変動の影響を受けることなく正確な予熱タイマー時間を設定して、放電灯６、１１のコールドスタートを防止することができる。 As described above, using the supply voltage of the high-frequency voltage supply circuit FS as a drive power supply, the oscillation frequency of the inverter circuit is increased from the drive frequency during normal lighting by a predetermined period, and then the oscillation frequency is set to the drive frequency during normal lighting. Since the preheating timer circuit TPH20 for reducing the temperature is provided, an accurate preheating timer time is set without being affected by the fluctuation of the time t1 to t2 when the preheating operation is not performed, and the cold start of the discharge lamps 6 and 11 is performed. Can be prevented.

実施の形態５．
図７は、この発明の実施の形態５を示す放電灯点灯装置の回路図、図８は放電灯点灯装置の動作説明図である。
図において、実施の形態１乃至４と同一又は相当する回路及び部品には同一の記号及び名称を付し説明を省略する。 Embodiment 5 FIG.
FIG. 7 is a circuit diagram of a discharge lamp lighting device according to Embodiment 5 of the present invention, and FIG. 8 is an operation explanatory diagram of the discharge lamp lighting device.
In the figure, circuits and components that are the same as or equivalent to those in the first to fourth embodiments are denoted by the same symbols and names, and description thereof is omitted.

図７において、２次巻線５ａ、及び１０ａに発生した電圧のピーク間電圧（ＰｅａｋｔｏＰｅａｋ電圧）の内、いずれか大きい方の電圧を出力コンデンサ６３の両端に検出するＰＰ検出回路ＰＰ１０（一点鎖線で示す）において、チョークコイル５の２次巻線５ａの一端は直流電源１の負極に接続され、他端からコンデンサ６７、コンデンサ６６を介して直流電源１の負極に接続される。ダイオード６５のアノードは直流電源１の負極に、カソードはコンデンサ６６とコンデンサ６７の接続点に接続される。ダイオード６５のカソードにダイオード６４のアノードが接続される。また、チョークコイル１０の２次巻線１０ａの一端は直流電源１の負極に接続され、他端からコンデンサ７１、コンデンサ７０を介して直流電源１の負極に接続される。ダイオード６９のアノードは直流電源１の負極に、カソードはコンデンサ７０とコンデンサ７１の接続点に接続される。ダイオード６９のカソードにダイオード６８のアノードが接続される。ダイオード６４とダイオード６８のカソードは接続され出力コンデンサ６３を介して直流電源１の負極に接続される。 In FIG. 7, a PP detection circuit PP10 (one point) for detecting the larger one of the voltages between the peaks of the voltages generated in the secondary windings 5a and 10a (Peak to Peak voltage) at both ends of the output capacitor 63. 1, one end of the secondary winding 5 a of the choke coil 5 is connected to the negative electrode of the DC power supply 1, and the other end is connected to the negative electrode of the DC power supply 1 via the capacitor 67 and the capacitor 66. The anode of the diode 65 is connected to the negative electrode of the DC power supply 1, and the cathode is connected to the connection point between the capacitor 66 and the capacitor 67. The anode of the diode 64 is connected to the cathode of the diode 65. Further, one end of the secondary winding 10 a of the choke coil 10 is connected to the negative electrode of the DC power supply 1, and the other end is connected to the negative electrode of the DC power supply 1 via the capacitor 71 and the capacitor 70. The anode of the diode 69 is connected to the negative electrode of the DC power supply 1, and the cathode is connected to the connection point between the capacitor 70 and the capacitor 71. The anode of the diode 68 is connected to the cathode of the diode 69. The cathodes of the diode 64 and the diode 68 are connected to each other and connected to the negative electrode of the DC power supply 1 through the output capacitor 63.

起動電圧供給回路ＶＳのダイオード２０のカソードからコンデンサ５１、抵抗５２、抵抗５３を介して直流電源１の負極に接続される。トランジスタ５４のベースは抵抗５２と抵抗５３の接続点に、エミッタは直流電源１の負極に接続される。トランジスタ５４のコレクタから抵抗５５を介してスイッチング素子２とスイッチング素子３の接続点に接続される。ダイオード８１のアノードはインバータ駆動回路３８の正の電源端子Ｖｃｃに、カソードは抵抗５５とトランジスタ５４のコレクタとの接続点に接続される。 The cathode of the diode 20 of the starting voltage supply circuit VS is connected to the negative electrode of the DC power supply 1 through the capacitor 51, the resistor 52, and the resistor 53. The base of the transistor 54 is connected to the connection point between the resistor 52 and the resistor 53, and the emitter is connected to the negative electrode of the DC power supply 1. The collector of the transistor 54 is connected to the connection point of the switching element 2 and the switching element 3 via the resistor 55. The anode of the diode 81 is connected to the positive power supply terminal Vcc of the inverter drive circuit 38, and the cathode is connected to the connection point between the resistor 55 and the collector of the transistor 54.

放電灯が寿命末期等の不良になった場合にインバータ回路の発振動作を停止・保持する保持回路Ｌａ１０（一点鎖線で示す）において、サイリスタ５６のアノードはダイオード８１のカソードに、カソードは直流電源１の負極に接続される。サイリスタ５６のゲートと直流電源１の負極との間に抵抗５７とコンデンサ５８の並列回路が接続される。ツェナーダイオード５９のアノードはサイリスタ５６のゲートに接続される。ツェナーダイオード５９のカソードから抵抗６０を介してダイオード６４のカソードに接続される。ツェナーダイオード５９のカソードと直流電源１の負極との間に電解コンデンサ６１と抵抗６２の並列回路が接続される。 In the holding circuit La10 (indicated by a one-dot chain line) that stops and holds the oscillation operation of the inverter circuit when the discharge lamp becomes defective at the end of its life, the anode of the thyristor 56 is the cathode of the diode 81, and the cathode is the DC power source 1. Connected to the negative electrode. A parallel circuit of a resistor 57 and a capacitor 58 is connected between the gate of the thyristor 56 and the negative electrode of the DC power supply 1. The anode of the Zener diode 59 is connected to the gate of the thyristor 56. The cathode of the Zener diode 59 is connected to the cathode of the diode 64 through the resistor 60. A parallel circuit of an electrolytic capacitor 61 and a resistor 62 is connected between the cathode of the Zener diode 59 and the negative electrode of the DC power supply 1.

以下、この発明の実施の形態５を示す放電灯点灯装置の動作を図７、図８により説明する。
時間ｔ１で直流電源１が投入されるとインバータ駆動回路３８の正の電源端子Ｖｃｃに電圧が印加され時間ｔ２で起動・発振することは図１で説明した実施の形態１と同様である（図８（ｃ）、（ｄ））。ＰＰ検出回路ＰＰ１０の出力コンデンサ６３の電圧は、放電灯が正常であれば時間ｔ１から時間ｔ３の期間の電圧を示しているが、例えば放電灯６がフィラメントの放電物質の消耗等の原因で寿命末期になればその電圧は上昇していく（図８（ｅ）時間ｔ３〜ｔ４）。そして、出力コンデンサ６３の電圧がツェナーダイオード５９で予め定めた電圧を超えればサイリスタ５６はＯＦＦからＯＮに転ずる（図８（ｆ））。サイリスタ５６がＯＮになればダイオード８１を介してインバータ駆動回路３８の正の電源端子Ｖｃｃ電圧は直流電源１の負極に接続されるのでインバータ駆動回路の発振は停止する（図８（ｄ））。ＯＮに転じたサイリスタ５６には直流電源１から抵抗１４、抵抗５５を介して電流が流れてサイリスタ５６はＯＮ状態を保持し続ける。 The operation of the discharge lamp lighting device according to Embodiment 5 of the present invention will be described below with reference to FIGS.
When the DC power supply 1 is turned on at time t1, a voltage is applied to the positive power supply terminal Vcc of the inverter drive circuit 38, and activation and oscillation at time t2 are the same as in the first embodiment described with reference to FIG. 8 (c), (d)). The voltage of the output capacitor 63 of the PP detection circuit PP10 indicates the voltage during the period from the time t1 to the time t3 if the discharge lamp is normal. For example, the discharge lamp 6 has a lifetime due to exhaustion of the discharge material of the filament. At the end of the period, the voltage increases (time t3 to t4 in FIG. 8 (e)). Then, when the voltage of the output capacitor 63 exceeds a voltage predetermined by the Zener diode 59, the thyristor 56 turns from OFF to ON (FIG. 8 (f)). When the thyristor 56 is turned on, the positive power supply terminal Vcc voltage of the inverter drive circuit 38 is connected to the negative electrode of the DC power supply 1 through the diode 81, and the oscillation of the inverter drive circuit stops (FIG. 8 (d)). A current flows from the DC power supply 1 through the resistor 14 and the resistor 55 to the thyristor 56 turned to ON, and the thyristor 56 continues to maintain the ON state.

ここで時間ｔ５で寿命末期になった放電灯６を抜去するとカップリングコンデンサ９及びコンデンサ２１の電圧は低下する（図８（ａ）、（ｂ））。そして、不良放電灯６を抜去してから正常放電灯を装着するまでの期間（時間ｔ５〜ｔ６の期間）にコンデンサ７の充電電圧が抵抗８を介して概略ゼロまで放電するように抵抗８を選定する。 Here, when the discharge lamp 6 that has reached the end of its life at time t5 is removed, the voltages of the coupling capacitor 9 and the capacitor 21 decrease (FIGS. 8A and 8B). Then, the resistor 8 is set so that the charging voltage of the capacitor 7 is discharged to approximately zero via the resistor 8 during the period from the removal of the defective discharge lamp 6 to the mounting of the normal discharge lamp (time t5 to t6). Select.

次に、時間ｔ６で放電灯６に正常な放電灯を装着すると、直流電源１、抵抗１４、充電電圧概略ゼロのコンデンサ７と抵抗８並列回路の経路でカップリングコンデンサ９に電流が流れその電圧は上昇していく。カップリングコンデンサ９の電圧を抵抗１８、抵抗１９で分圧して得られるコンデンサ２１の電圧も同様に上昇していく（図８（ａ）、（ｂ））。コンデンサ２１の上昇していく変化電圧はコンデンサ５１を介して抵抗５２と抵抗５３の直列回路に微分電圧波形として得られる。図８（ｈ）の時間ｔ６近傍の波形は微分電圧波形の抵抗５３の電圧を示している。抵抗５３に発生する電圧によってトランジスタ５４は、ｔ６ａ〜ｔ６ｂで一瞬ＯＮし（図８（ｇ））、抵抗５５からサイリスタ５６に流れている電流をバイパスするので、サイリスタ５６の電流はその保持電流以下となりｔ６ａでＯＦＦに転ずる。サイリスタ５６及びトランジスタ５４がＯＦＦになればインバータ駆動回路３８の正の電源端子Ｖｃｃ電圧は上昇し時間ｔ７で再起動し、以降発振は継続し放電灯は正常放電状態となる（図８（ｄ）、（ｅ））。 Next, when a normal discharge lamp is mounted on the discharge lamp 6 at time t6, a current flows to the coupling capacitor 9 through the path of the DC power source 1, the resistor 14, the capacitor 7 having a charging voltage of almost zero, and the resistor 8 parallel circuit, and the voltage Will rise. Similarly, the voltage of the capacitor 21 obtained by dividing the voltage of the coupling capacitor 9 by the resistors 18 and 19 also increases (FIGS. 8A and 8B). The increasing voltage of the capacitor 21 is obtained as a differential voltage waveform in the series circuit of the resistor 52 and the resistor 53 via the capacitor 51. A waveform in the vicinity of time t6 in FIG. 8H indicates the voltage of the resistor 53 having a differential voltage waveform. The transistor 54 is turned on for a moment from t6a to t6b by the voltage generated in the resistor 53 (FIG. 8 (g)), and the current flowing from the resistor 55 to the thyristor 56 is bypassed. And turns off at t6a. When the thyristor 56 and the transistor 54 are turned off, the voltage of the positive power supply terminal Vcc of the inverter drive circuit 38 rises and restarts at time t7. Thereafter, the oscillation continues and the discharge lamp enters a normal discharge state (FIG. 8D). (E)).

以上のように、本実施の形態５によれば、放電灯負荷回路Ｌ１０のチョークコイル５、６の２次巻線５ａ、１０ａに発生するピーク間電圧を検出するＰＰ検出回路ＰＰ１０と、このＰＰ検出回路ＰＰ１０で検出されたピーク間電圧が予め定めた値より大きいときに、インバータ回路の発振を停止・保持し、放電灯６、１１、または、いずれか一方が抜去後再装着されたときに、直流電源１から放電灯のフィラメントを介してカップリングコンデンサ９に流れる電流によって発生する電圧に基づいてインバータ回路の停止・保持状態を解除する保持回路Ｌａ１０を備えたので、放電灯の不良状態での点灯を防止することができる。
また、直流電源１を投入したままでも不良放電灯を抜去し、正常放電灯と置換することでインバータ回路の再起動をすることができる。
これによって１つの電源系統に多数の放電灯器具が設置されている場合でも、電源を一括して遮断することなく、不良放電灯の交換作業が可能である。 As described above, according to the fifth embodiment, the PP detection circuit PP10 that detects the peak-to-peak voltage generated in the secondary windings 5a and 10a of the choke coils 5 and 6 of the discharge lamp load circuit L10, and the PP When the peak-to-peak voltage detected by the detection circuit PP10 is larger than a predetermined value, the oscillation of the inverter circuit is stopped and held, and when the discharge lamp 6, 11 or one of them is removed and remounted. Since the holding circuit La10 for releasing the stop / hold state of the inverter circuit based on the voltage generated by the current flowing from the DC power source 1 to the coupling capacitor 9 through the filament of the discharge lamp is provided, the discharge lamp is in a defective state. Can be prevented from being turned on.
Further, the inverter circuit can be restarted by removing the defective discharge lamp and replacing it with a normal discharge lamp even with the DC power supply 1 turned on.
As a result, even when a large number of discharge lamp fixtures are installed in one power supply system, the defective discharge lamp can be replaced without shutting off the power supply collectively.

なお、上記説明では放電灯６が寿命末期になった場合について説明したが、放電灯１１が寿命末期になった場合及び２つの放電灯が同時に寿命末期になった場合でも同様の効果ある。
また、図６のカップリングコンデンサの構成を実施の形態２の図３に示すように各放電灯５、１１に対応して個別に設けてもよい。。
また、図６の回路に実施の形態３の図４に示す予熱タイマー回路を設けても同様の効果がある。 In the above description, the case where the discharge lamp 6 has reached the end of life has been described. However, the same effect can be obtained when the discharge lamp 11 has reached the end of life and when two discharge lamps have reached the end of life at the same time.
Further, the configuration of the coupling capacitor of FIG. 6 may be provided individually corresponding to each of the discharge lamps 5 and 11 as shown in FIG. 3 of the second embodiment. .
6 can be provided with the preheating timer circuit shown in FIG. 4 of the third embodiment.

この発明の実施の形態１を示す放電灯点灯装置の回路図である。It is a circuit diagram of the discharge lamp lighting device which shows Embodiment 1 of this invention. この発明の実施の形態１を示す放電灯点灯装置の動作説明図である。It is operation | movement explanatory drawing of the discharge lamp lighting device which shows Embodiment 1 of this invention. この発明の実施の形態２を示す放電灯点灯装置の回路図である。It is a circuit diagram of the discharge lamp lighting device which shows Embodiment 2 of this invention. この発明の実施の形態３を示す放電灯点灯装置の回路図である。It is a circuit diagram of the discharge lamp lighting device which shows Embodiment 3 of this invention. この発明の実施の形態３を示す放電灯点灯装置の動作説明図である。It is operation | movement explanatory drawing of the discharge lamp lighting device which shows Embodiment 3 of this invention. この発明の実施の形態４を示す放電灯点灯装置の回路図である。It is a circuit diagram of the discharge lamp lighting device which shows Embodiment 4 of this invention. この発明の実施の形態５を示す放電灯点灯装置の回路図である。It is a circuit diagram of the discharge lamp lighting device which shows Embodiment 5 of this invention. この発明の実施の形態５を示す放電灯点灯装置の動作説明図である。It is operation | movement explanatory drawing of the discharge lamp lighting device which shows Embodiment 5 of this invention.

Explanation of symbols

１直流電源、２、３スイッチング素子、５、１０チョークコイル、５ａ、１０ａ２次巻線、６、１１放電灯、７、１２、１５、２１、３３コンデンサ、８．１３、１６、１８、１９、２２、３１抵抗、９、９ａ、９ｂカップリングコンデンサ、１７、２０、２０ａ、２０ｂ、３２、３５ダイオード、３４ツェナーダイオード、３８インバータ駆動回路、Ｌ１０放電灯負荷回路、Ｌ２０、３０放電灯負荷回路、ＴＰＨ１０、ＴＰＨ２０予熱タイマー回路、Ｌａ１０保持回路、ＰＰ１０ＰＰ検出回路、ＶＳ、ＶＳ１起動電圧供給回路、ＦＳ高周波電圧供給回路。
1 DC power supply, 2, 3 switching element, 5, 10 choke coil, 5a, 10a secondary winding, 6, 11 discharge lamp, 7, 12, 15, 21, 33 capacitor, 8.13, 16, 18, 19 , 22, 31 Resistance, 9, 9a, 9b Coupling capacitor, 17, 20, 20a, 20b, 32, 35 Diode, 34 Zener diode, 38 Inverter drive circuit, L10 Discharge lamp load circuit, L20, 30 Discharge lamp load circuit , TPH10, TPH20 preheating timer circuit, La10 holding circuit, PP10 PP detection circuit, VS, VS1 start-up voltage supply circuit, FS high frequency voltage supply circuit.

Claims

DC power supply,
An inverter circuit composed of a half-bridge circuit having two switching elements for converting a direct current supplied from the direct current power source into a high frequency current;
An inverter drive circuit for driving the inverter circuit;
A choke coil, a series circuit of a coupling capacitor connected to the choke coil via a discharge lamp, a discharge lamp load circuit comprising a capacitor connected in parallel to the discharge lamp,
An activation voltage supply circuit for supplying a voltage for oscillating and activating the inverter drive circuit based on a current flowing through the coupling capacitor;
A high-frequency voltage supply circuit that supplies a high-frequency voltage generated based on a high-frequency current output of any one of the switching elements to the inverter drive circuit;
A discharge lamp lighting device comprising:

The starting voltage supply circuit includes a rectifying / smoothing circuit that rectifies and smoothes a voltage generated by a current flowing through the coupling capacitor;
A capacitor for charging the output voltage of the rectifying and smoothing circuit;
The discharge lamp lighting device according to claim 1, further comprising:

DC power supply,
An inverter circuit composed of a half-bridge circuit having two switching elements for converting a direct current supplied from the direct current power source into a high frequency current;
An inverter drive circuit for driving the inverter circuit;
A choke coil, a series circuit of coupling capacitors connected to the choke coil via a discharge lamp, a plurality of discharge lamp load circuits comprising capacitors connected in parallel to the discharge lamp,
An activation voltage supply circuit for supplying a voltage for oscillating and activating the inverter drive circuit based on a current flowing through each coupling capacitor of each discharge lamp load circuit;
A high-frequency voltage supply circuit that supplies a high-frequency voltage generated based on a high-frequency current output of any one of the switching elements to the inverter drive circuit;
A discharge lamp lighting device comprising:

The starting voltage supply circuit includes a rectifying / smoothing circuit that rectifies and smoothes a voltage generated by a current flowing through each coupling capacitor;
A capacitor for charging the output voltage of the rectifying and smoothing circuit;
The discharge lamp lighting device according to claim 3, further comprising:

The high-frequency voltage supply circuit includes a series circuit of a capacitor, a resistor, and a diode connected in parallel to the switching element,
A diode having an anode connected to the connection point of the resistor and the diode, and a cathode connected to the positive power supply terminal of the inverter drive circuit;
A Zener diode having a cathode connected to the positive power supply terminal of the inverter drive circuit and an anode connected to the negative electrode of the DC power supply;
The discharge lamp lighting device according to any one of claims 1 to 4, further comprising:

6. A discharge lamp lighting device according to claim 1, wherein a parallel resistor is connected to the discharge lamp.

A preheating timer that uses the supply voltage of the start-up voltage supply circuit as a drive power source and increases the oscillation frequency of the inverter circuit for a predetermined period from the drive frequency during normal lighting, and then reduces the oscillation frequency to the drive frequency during normal lighting The discharge lamp lighting device according to any one of claims 1 to 6, further comprising a circuit.

A preheating timer that uses the supply voltage of the high-frequency voltage supply circuit as a drive power supply and increases the oscillation frequency of the inverter circuit for a predetermined period from the drive frequency during normal lighting, and then reduces the oscillation frequency to the drive frequency during normal lighting The discharge lamp lighting device according to any one of claims 1 to 6, further comprising a circuit.

A peak-to-peak voltage detection circuit for detecting a peak-to-peak voltage generated in the secondary winding of the choke coil of the discharge lamp load circuit;
When the peak-to-peak voltage detected by this peak-to-peak voltage detection circuit is greater than a predetermined value, the oscillation of the inverter circuit is stopped and held, and when the discharge lamp is removed and remounted, A holding circuit for releasing the stop / hold state of the inverter circuit based on a voltage generated by a current flowing through the coupling capacitor through the filament of
The discharge lamp lighting device according to any one of claims 1 to 8, further comprising: