JP2948627B2 - Discharge lamp lighting device - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a discharge lamp lighting device for starting and lighting a high pressure discharge lamp such as a metal halide lamp or a high pressure sodium lamp.

[Related Art] Conventionally, many devices for starting and lighting a high-pressure discharge lamp have been proposed. For high-pressure discharge lamps, for example, in the case of Osram HQI, it is necessary to apply a high-voltage pulse voltage of about several KV to both ends of the lamp at the time of starting, and the same high-voltage pulse voltage is necessary at the time of other high-pressure discharge lamps And In order to generate such a high voltage pulse, various methods have been proposed as described below.

Conventional Example 1 FIG. 14 is a block circuit diagram of a typical lighting device of a high pressure discharge lamp. The AC voltage of the AC power supply Vs is supplied to the igniter IG and the high-pressure discharge lamp DL via the ballast B. At the start, the igniter IG generates the high-voltage pulse voltage. However, this type of high-pressure discharge lamp has a very high operating temperature of several hundred to several thousand degrees Celsius during operation, and once it is turned off, it can be restarted if the lamp temperature does not drop to about room temperature. It took about 5 to 10 minutes during this time. Therefore, in order to shorten the time until restart, several tens of digits higher than at the start
It is generally known that when a high-voltage pulse voltage of KV is applied, the lamp can be restarted instantaneously even immediately after the lamp is turned off.

Conventional Example 2 In the lighting device shown in FIG. 15 (see Japanese Patent Application Laid-Open No. 57-165999), the time required for restart is shortened by the above principle. That, ON switches S ₀ for restarting Then, an AC voltage from an AC power source Vs is boosted by the step-up transformer Tr _1, when the boosted voltage reaches the discharge starting voltage of the discharge gap G, the capacitor C _2, the discharge Discharge occurs in the gap G and the closed circuit of the primary winding of the pulse transformer Tr. Due to this discharge, a high-voltage pulse voltage of about several tens of KV is generated in the secondary winding of the pulse transformer Tr, and the high-pressure discharge lamp DL can be turned on instantaneously even in a state where starting is difficult, such as when restarting. In the figure, L ₁ is a ballast, C ₁ is a capacitor for high frequency bypass for applying a high pulse voltage to the high-pressure discharge lamp DL.

In this conventional example, the step-up transformer Tr ₁ is the input of the primary-side alternating voltage of 100V or 200V, since the by generating a voltage thousands V on the secondary side, the step-up ratio increases, secondary winding Very many lines. Further, since it is necessary to be designed to withstand high voltages, the step-up transformer Tr ₁ is very large. Further, after the lamp is turned on, the switch S ₀ for restart is used.
Must be turned off to stop the generation of the high-voltage pulse.

Conventional Example 3 FIG. 16 shows another conventional example (see Japanese Patent Application Laid-Open No. 59-196594). In this conventional example, by using a voltage doubler rectifier circuit by the capacitor C ₇ and the diode D _51, D _52, with the step-up ratio can be reduced, the step-up transformer Tr
_{Since the} inverter 1 operates at a high frequency by the inverter circuit 1, the size of the step-up transformer Tr ₁ can be reduced. However, as the conventional example 2, it is necessary to provide a switch S ₀ for restart.

Conventional Example 4 FIG. 17 is a circuit diagram of another conventional example. In this circuit,
The igniter IG operates with the secondary voltage of the ballast B (for example, a commercial frequency lighting circuit, a high frequency lighting circuit using an inverter, or a rectangular wave lighting circuit). That is, the no-load secondary voltage generated between the terminals a and b of the ballast B is rectified by the rectifier circuit 3 and the switching transistor
The Q ₅ drives on and off at a high frequency, the step-up transformer Tr ₁ boosts a secondary voltage up to several thousand V, rectifier diode
Through D ₅ to charge the capacitor C _2. When the voltage of the capacitor C ₂ reaches the discharge starting voltage of the discharge gap G, the capacitor C _2, 1 winding of the pulse transformer Tr, discharges a closed circuit of the discharge gap G. As a result, a high-voltage pulse voltage of several tens of KV is generated on the secondary side of the pulse transformer Tr,
Is applied to the high-pressure discharge lamp DL through the capacitor C _1, thereby enabling start instantly even start difficult conditions such as during restarting.

In this conventional example, when the high-pressure discharge lamp DL is turned on, the voltage between the terminals a and b of the ballast B decreases substantially to the lamp voltage, so that the output of the igniter IG automatically decreases or stops.
Accordingly, the generation of the high-voltage pulse voltage stops automatically, switches S ₀ private becomes unnecessary.

[Problem to be Solved by the Invention] In the above-described conventional example 4, since the no-load secondary voltage of the ballast B decreases during the operation of the igniter IG, the high-pressure discharge lamp DL shifts from glow discharge to arc discharge. The required power cannot be supplied sufficiently, and a problem arises in that the starting performance is reduced. That is, when the igniter IG is not operating, the no-load secondary voltage of the ballast B becomes a voltage as shown in FIG. 18 (a) or (b). (A) or (b). In the figure, Vp is the high-voltage pulse voltage, and the other solid lines are the no-load secondary voltages of the ballast B. In each of the above figures, FIG. 7A shows an operation waveform in the case of high-frequency lighting, and FIG. 7B shows an operation waveform in the case of low-frequency rectangular wave lighting. In the case of FIGS. 19 (a) and (b),
The reason why the no-load secondary voltage is lower than in the cases of FIGS. (A) and (b) is that the igniter IG is almost always operated, so that the power consumption of the igniter IG increases and the internal This is because a voltage drop due to impedance occurs.

The present invention has been made in view of such a point,
The object is to provide a lighting device for a high-pressure discharge lamp having an igniter that operates at a no-load secondary voltage of a ballast, by operating the igniter only during a predetermined period of the no-load secondary voltage of the ballast, An object of the present invention is to minimize the reduction of the no-load secondary voltage and improve the starting / restarting performance.

[Means for Solving the Problems] In the present invention, in order to solve the above problems, as shown in FIG. 1, a high-pressure discharge lamp DL, a secondary winding of a pulse transformer Tr, and a first A closed circuit is constituted by the capacitor C ₁ and the first output is supplied to the output of the inverter circuit 1 supplied from the input power source E.
Connect the capacitor C ₁ in parallel, the second capacitor C ₂ and the discharge gap G and the pulse transformer Tr which is charged by intermittently boosted rectified voltage output of the rectangular wave voltage of the inverter circuit 1 1 A closed circuit is formed with the next winding.

Incidentally, to generate a square wave voltage of low frequency by the inverter circuit 1, by inserting the capacitor C ₃ of DC blocking between the inverter circuit 1 and the step-up circuit 2, the generation period of the high pressure pulse voltage of a rectangular wave voltage polarity It can be limited to immediately after inversion. If the first operation period in which the inverter circuit 1 generates the low-frequency rectangular wave voltage and the second operation period in which the high-frequency voltage is generated are alternated, the high-voltage pulse voltage generation period is changed to the second operation period. The period can be limited. In addition, even if there is no capacitor C ₃ for DC cut,
If the booster circuit 2 is operated intermittently, the timing for generating the high-voltage pulse voltage can be limited.

In the [Operation] The present invention, thus, it is so arranged to charge the capacitor C ₂ for high pressure pulse voltage generated by intermittently boosted rectified voltage output of the inverter circuit 1, always inverter circuit 1 Is not consumed for generating the high-voltage pulse voltage. Therefore, a period in which the charging of the capacitor C ₂ for high pressure pulse voltage generator is dormant,
A voltage that promotes transition to arc discharge can be given to the high-pressure discharge lamp DL by the output of the inverter circuit 1,
The starting characteristics and the restart characteristics can be improved.

Embodiment 1 FIG. 2 is a circuit diagram of a first embodiment of the present invention. Less than,
The circuit configuration will be described. The DC input power supply E includes a series circuit of transistors Q ₁ and Q ₃ and transistors Q ₂ and Q ₃ .
A series circuit of Q ₄ are parallel connected. Each transistor Q ₁ to Q _4, respectively diodes D ₁ to D ₄ are connected in antiparallel. Between the connection point of the transistor Q _1, the connection point of Q ₃ and the transistor Q _2, Q _4, through the inductor L ₁ is connected to the capacitor C _1, to both ends of the capacitor C _1, a pulse transformer high-pressure discharge lamp DL is connected via the secondary winding n ₅ of tr.

FIG. 3 is an operation waveform diagram of the present embodiment. Transistor
Q ₁ and Q ₂ operate alternately at a high frequency of about several tens KHz, and transistors Q ₃ and Q ₄ operate alternately at a low frequency of about 100 to several hundred Hz. Then, when the transistor Q ₄ is turned on, the transistor Q ₁ is then turned on and off, when the transistor Q ₃ is turned on, the transistor Q ₂ is turned on and off. At this time, since the inductor L ₁ and capacitor C ₁ acts as a low pass filter, between the terminals a-b of the inverter circuit, a rectangular wave voltage having the same frequency as the operating frequency of the transistor Q _3, Q ₄ is generated.

Next, the configuration of the igniter IG will be described. Terminal a
Between -b, it is connected to AC input terminals of the diode bridge DB via a capacitor C ₃ of DC blocking capacitor C ₄ is between DC output terminals c-d of the diode bridge DB is connected in parallel I have. The both ends of the capacitor C _4, 1 winding n ₁ of the step-up transformer Tr ₁ is connected via the transistor Q _5. With the base of the transistor Q ₅ is activated current is supplied through the starting resistor R _g, a drive current is supplied from the feedback winding n ₃ via a base resistor R _B.
These step-up transformer Tr ₁ and the transistor Q ₅ and the resistor R _g,
R _B constitute an inverter circuit of one stone self-excited boosts the voltage between the terminals c-d obtained in the capacitor C _4. The secondary winding n ₂ of the oscillation transformer Tr _1, the capacitor C ₂ through the diode D ₅ is connected. Capacitor C ₂ is connected to the primary winding n ₄ of the pulse transformer Tr with a discharge gap G.

This igniter IG has terminals ab as shown in FIG.
Is intended to operate in response to the rectangular wave voltage between, since the capacitor C ₃ for DC cutting is inserted into the input side, as shown in FIG. 5, the polarity of the voltage between the terminals a-b is inverted Only when this occurs, a voltage is generated between the terminals cd. The operation of this part is shown in detail in FIGS. 6 (a) to (d). Terminal c
When a voltage as shown in FIG. 6A is generated between −d,
Start resistance starting current flows to the base of the transistor Q ₅ through R _g, the transistor Q ₅ is turned on. Transistor Q ₅
There is turned on, the boosted voltage to the primary winding n ₁ of the transformer Tr ₁ is generated, a voltage is generated in accordance with the turns ratio in the feedback winding n _3. Transistor Q ₅ through a base resistor R _B in the voltage
Further base current flows, the transistor Q ₅ is completely turned on. Thus, as shown in FIG. 6 (b), the collector current of the transistor Q ₅ flows. It becomes a predetermined value or more is this current is in turn becomes insufficient base current, the emitter of the transistor Q ₅ - a collector voltage V _CE rises, the voltage of the winding n _1, n ₃ of the step-up transformer Tr ₁ is reduced Therefore, it becomes more base current shortage, the transistor Q ₅ is suddenly turned off. When the transistor Q ₅ is turned off, the energy accumulated in the step-up transformer Tr ₁ is charged into the capacitor C ₂ through the diode D _5. When the energy of the step-up transformer Tr ₁ is exhausted to release, the transistor Q ₅ is turned on again, following this operation is repeated. Accordingly, the voltage of the capacitor C ₂ rises as shown in Figure No. 6 (c). Then, the discharge starting voltage V _G of the discharge gap _G
(E.g. thousands V) reaches the charge stored in the capacitor C ₂ is the primary winding n ₄ of the pulse transformer Tr, rapidly discharged through the discharge lamp gap G, this time, the pulse transformer high-voltage pulse voltage according to the turns ratio of the Tr ₂ (for example, several tens of KV) as shown in the FIG. 6 (d), generated in the secondary winding n ₅ of the pulse transformer Tr, capacitor C ₁ for high frequency bypass Is applied to the high-pressure discharge lamp DL. Thereby, for example, even in a state where it is very difficult to restart immediately after the lamp is turned off, the high-pressure discharge lamp DL is turned on instantaneously. Seventh
The figure shows the waveform of the voltage across the high-pressure discharge lamp DL at the start. In the figure, Vp is a high pulse voltage, V ₀₂ is unloaded 2
Next voltage.

This embodiment is characterized in that the output terminals ab
Igniter IG only for a certain period immediately after voltage polarity inversion during
Operates to generate a high-voltage pulse voltage, so that a sufficient no-load secondary voltage can be secured between the output terminals a and b of the inverter circuit during the suspension period of the high-voltage pulse voltage. With this, it is possible to supply energy for shifting the high pressure discharge lamp DL from glow discharge to arc discharge,
The starting performance of the high-pressure discharge lamp DL is greatly improved.
Further, when the high-pressure discharge lamp DL is turned on, the voltage between the terminals a and b substantially falls to the lamp voltage. For example, if the no-load secondary voltage is about 280 V, the lamp voltage drops to about 90 V after starting the high-pressure discharge lamp DL. Therefore, the operation of the igniter IG is stopped, the high-voltage pulse voltage is completely stopped while the high-pressure discharge lamp DL is lit, and the high-pressure discharge lamp DL can be stably maintained.

Second Embodiment FIG. 8 is a circuit diagram of a second embodiment of the present invention. In this embodiment, the transistor in the first embodiment shown in FIG.
Instead of Q ₁ , Q ₃ and diodes D ₁ , D ₃ , transistors Q ₆ , Q ₇
And diodes D ₆ and D ₇ , and capacitors C ₅ and C ₆ instead of the transistors Q ₂ and Q ₄ and diodes D ₂ and D ₄ , forming a half-bridge type inverter circuit. ing. Therefore, the voltage obtained between the terminals a and b is about half as compared with the first embodiment using the full-bridge type inverter circuit.

FIG. 9 is an operation waveform diagram of the present embodiment. As shown in the figure, in the first period T _1, the transistor Q ₇ is turned off, repeatedly turning on and off the transistor Q ₆ is at a high frequency of about several 10 KHz, the second period T _2, the transistor Q ₆ There turned off, the transistor Q ₇ is repeatedly turned on and off by the above-mentioned high frequency. Thus, the voltage obtained between the terminals a-b is a rectangular wave voltage polarity is reversed at the period T ₁ and the second period T _2. Since the circuit configuration of the igniter IG is the same as that of the first embodiment, the illustration is omitted.

Also in this embodiment, the terminals ab of the inverter circuit
The no-load secondary voltage obtained in between is a rectangular wave voltage having _one cycle of the first and second periods (T ₁ + T ₂ ), and a high-voltage pulse voltage is generated only immediately after the polarity reversal of the voltage. Yes, the operation is the same as in the first embodiment.

Third Embodiment FIG. 10 is a circuit diagram of a third embodiment of the present invention. In this embodiment, when the lamp is started (no load), as shown in FIG. 11, it operates as a high-frequency inverter in the periods t ₁ and t ₃ , and in the periods t ₂ and t ₄ , as in the first embodiment. It operates as a low frequency rectangular wave inverter. In the operation periods t ₁ and t ₃ as the high-frequency inverter, for example, when the transistors Q ₁ and Q ₄ are on, the transistors Q ₂ and Q ₃ are off, and conversely, when the transistors Q ₁ and Q ₄ are off Is
Transistor Q ₂ and Q ₃ are turned on, and performs the operation in a high frequency alternating.

Next, the igniter IG used in the present embodiment will be described. In the operation periods t ₁ and t ₃ as the high-frequency inverter, the transistors Q _{1 to} Q ₄ perform switching operation at a high frequency, so that the high-frequency inverter is connected to the primary side of the step-up transformer Tr ₁ via the DC cut capacitor C _3. And a boosted voltage is generated on the secondary side. The boosted voltage is full-wave rectified by the diodes D ₅₁ and D ₅₂ , and the electric charge is stored in the capacitor C ₂ . The voltage rises capacitor C _2, and reaches the discharge starting voltage of the discharge gap G, the charge of capacitor C ₂ is the primary winding of the pulse transformer Tr, abruptly discharged via a discharge gap G. At this time, the pulse transformer Tr 2
The following side, high-voltage pulse voltage is generated in accordance with the turns ratio, it is applied to the high-pressure discharge lamp DL through the capacitor C _1.
That is, in this embodiment, the high-voltage pulse voltage is generated only during the operation periods t ₁ and t ₃ as the high-frequency inverter.

On the other hand, the operating period as a low-frequency square wave inverter
At t ₂ and t ₄ , due to the presence of the DC cut capacitor C ₃ ,
As in the first embodiment, the igniter IG does not operate. Therefore, a regular and stable no-load secondary voltage is secured between the terminals a and b of the inverter circuit, and sufficient energy for shifting from glow discharge to arc discharge is supplied. Become. When the high-pressure discharge lamp DL is turned on, the operation periods t ₁ and t ₃ as the high-frequency inverter may be omitted, and the operation may be performed in the same manner as in the first embodiment. Alternatively, the entire duration t ₁ ~t _4, may be allowed an inverter operating at a frequency to the extent that the igniter IG does not work. This is the same for the first and second embodiments.

Fourth Embodiment FIG. 12 shows a circuit according to a fourth embodiment of the present invention. Between terminals a-b of the inverter circuit shown in the first or second embodiment, by connecting the igniter IG as shown in FIG. 12, even without the capacitor C ₃ of DC blocking, the igniter IG It can be operated intermittently. In this embodiment, in order to operate the igniter IG intermittently, the transistor Q ₅
Is controlled separately, and the intermittent oscillation circuit 4 controls the transistor.
And intermittently frequency driving the Q _5. In other words, instead of superimposing the high-voltage pulse voltage on almost the entire region of the rectangular wave voltage,
As shown in Fig. 13, the igniter is used only for a certain period.
The IG is operated to intermittently superimpose the high-voltage pulse voltage Vp. In this way, during the period when the igniter IG is not operating, a sufficient no-load secondary voltage can be secured between the terminals a and b, and the starting performance of the high-pressure discharge lamp DL is improved.

In the field of starters for fluorescent lamps, for example,
Although there is a cycle-by-cycle lighting system as described in the prior art of Japanese Patent Application Laid-Open No. 58-10397, in the present invention, the main lighting circuit is constituted by an inverter circuit, and operates with the output of the inverter circuit. The igniter IG is different in that the igniter IG is also configured by an inverter circuit. In addition, igniter IG
Also different that it has a switching element consisting of a discharge gap G for rapidly discharging the electric charge of the capacitor C _2, the present invention has a lighting device particularly adapted to the high-pressure discharge lamp DL.

[Effects of the Invention] In the present invention, as described above, in a lighting device that generates a high-voltage pulse voltage for starting a high-pressure discharge lamp using a no-load secondary voltage of a ballast as a power supply, By generating it only during a certain period, a sufficient no-load secondary voltage can be applied to the high-pressure discharge lamp during the period when the high-voltage pulse voltage is not generated,
There is an effect that a discharge lamp lighting device with very good starting performance and restart performance can be provided. In addition, the ballast has no load 2
Since the high voltage pulse voltage is generated by using the next voltage as a power source, when the high voltage discharge lamp is started and the lamp voltage is reduced, the generation of the high voltage pulse voltage is automatically stopped. There is an effect that the life of the discharge gap is improved.

[Brief description of the drawings]

FIG. 1 is a circuit diagram showing a basic configuration of the present invention, FIG. 2 is a circuit diagram of a first embodiment of the present invention, FIGS. 3 to 7 are operation waveform diagrams of the same, and FIG. Circuit diagram of second embodiment, ninth embodiment
FIG. 10 is an operation waveform diagram of the above embodiment, FIG. 10 is a circuit diagram of the third embodiment of the present invention, FIG. 11 is an operation waveform diagram of the above embodiment, FIG. 12 is a circuit diagram of the fourth embodiment of the invention, FIG. The figure shows the operation waveform diagram of the above,
Fig. 15 is a block diagram of a conventional example, Fig. 15 is a circuit diagram of another conventional example, Fig. 16 is a circuit diagram of another conventional example, Fig. 17 is a circuit diagram of another conventional example, Figs. FIG. 19 is an operation waveform diagram of the above. 1 is an inverter circuit, 2 is a booster circuit, 3 is a rectifier circuit,
C ₁ , C ₂ , C ₃ are capacitors, G is a discharge gap, Tr is a pulse transformer, DL is a high-pressure discharge lamp, and E is an input power supply.

────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-57-38594 (JP, A) JP-A-1-194295 (JP, A) JP-A-1-298687 (JP, A) JP-A-1- 167987 (JP, A) JP-A-1-298686 (JP, A) JP-A-1-298688 (JP, A) JP-A-59-175597 (JP, A) JP-A-59-196595 (JP, A) Hikaru Hei 1-172299 (JP, U) (58) Field surveyed (Int. Cl. ⁶ , DB name) H05B 41/14-41/29

Claims (1)

(57) [Claims] 1. A closed circuit is constituted by a high-pressure discharge lamp, a secondary winding of a pulse transformer, and a first capacitor, and a first capacitor is connected in parallel to an output of a ballast supplied from an input power supply. A closed circuit is constituted by a second capacitor charged by a voltage obtained by intermittently boosting and rectifying the rectangular wave voltage output of the ballast, a discharge gap, and a primary winding of the pulse transformer. Discharge lamp lighting device.