JPS6135680B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a discharge lamp lighting device for lighting multiple discharge lamps connected in series using the output of a high frequency AC power source. 2. Description of the Related Art Conventionally, a discharge lamp lighting device shown in FIG. 1 is well known as a discharge lamp lighting device using a high frequency AC power supply device that outputs a high frequency AC voltage of several KHz to several hundred KHz. This item is used as a high frequency AC power supply A1.
For example, a device in which the primary winding 3a of the output transformer 3 is connected to the output end of the high frequency power converter 2 connected to the AC power supply 1 is used, and the secondary winding 3 of the transformer 3 is
b is connected to the filament terminal of the discharge lamp 5 via the current limiting capacitor 4, and the preheating windings 3c and 3d of the transformer 3 are connected to the filament terminal of the discharge lamp 5 via the capacitors 6 and 7, respectively. ,
Further, a conductor 8 is arranged along the discharge lamp 5, and one end of the conductor 8 is connected to one flight terminal of the discharge lamp 5. In this device, the filament of the discharge lamp 5 is preheated by the output of the preheating windings 3c and 3d, and the discharge lamp 5 is started by the output of the secondary winding 3d. This is designed to promote the rise of discharge and facilitate starting. In other words, the conductor 8 promotes discharge at the time of starting the discharge lamp, thereby making it possible to lower the starting voltage. Therefore, conventionally, this is worn, and as an example, the second
It is being considered that the above-mentioned conductor is applied to a device for lighting two lamps in series as shown in the figure in hopes of reducing the starting voltage. In other words, the one in FIG. 2 is a high-frequency AC power supply A2 similar to the one in FIG. A series circuit of discharge lamps 15 and 16 is connected between the secondary winding 13b of the transformer 13 via a current-limiting capacitor 14, and a conductor 17 is arranged along these discharge lamps 15 and 16. One end of this conductor 17 is connected to one end of the discharge lamp 16, that is, the end opposite to the end connected to the discharge lamp 15. Here, 18 in the figure is a starting aid capacitor. In addition, the discharge lamp 15,
Although the filament preheating circuit No. 16 is omitted,
It can be constructed by providing a preheating winding as shown in FIG. However, when we experimented to determine the starting voltage of such a device for lighting two lamp rows in order to understand the effect of the conductor 17, we could not expect a significant effect compared to the above-mentioned one for lighting a single lamp. The lighting operation sometimes became unstable. Therefore, this invention solves the above problems,
It is an object of the present invention to provide a discharge lamp lighting device for lighting multiple lamps in series, which can be expected to reduce the starting voltage. An embodiment of the present invention will be described below with reference to the drawings. FIG. 3 shows an example in which the present invention is applied to two lights in series. That is, in FIG. 3, the high frequency AC power supply device A3
For example, an output transformer 25 is connected to the output end of a high frequency power converter 22 connected to an AC power source 21. Here, the high frequency power converter 22 connects the input terminal of the full wave rectifier circuit 23 to the AC power supply 21,
A capacitor 2 is connected between the output terminal of the rectifier circuit 23.
4, the positive terminal of the output terminal is connected to the midpoint of the primary winding 25a of the output transformer 25, and the negative terminal is connected to the transistor 27 through the reactor 26.
The collector of the transistor 27 is connected to one end of the primary winding 25a, and the base of the transistor 27 is connected to the midpoint of the primary winding 25a via a bias resistor 29. The collectors of the transistors 27 and 28 are connected to the other side of the primary winding 25a, and the bases are connected to the midpoint of the primary winding 25a via a bias resistor 30, and the bases of the transistors 27 and 28 are connected to the output transformer 25. are connected to the feedback windings 25b, respectively. Here, 31 in the figure is a resonance capacitor. Such a high frequency AC power supply device A3 itself is well known, and outputs a high frequency AC voltage of several KHz or more, preferably an audio frequency or more. On the other hand, the output transformer 25 connects a discharge lamp 33 and a current-limiting capacitor 32 between the secondary winding 25c.
Connect 34 series circuits. Further, the output transformer 25 connects the preheating winding 25d among the preheating windings 25d, 25e, and 25f to one of the filament terminals of the discharge lamp 33 via the capacitor 35, and connects the preheating winding 25e to the filament terminal of the discharge lamp 33 via the capacitor 36. Discharge lamp 34
The remaining preheating winding 25f is connected via a capacitor 37 to the other filament terminals of the commonly connected discharge lamps 33 and 34. In the present invention, a conductor 38 is arranged along the discharge lamps 33 and 34, and this conductor 38 is connected to the commonly connected filament terminal of the discharge lamps 33 and 34. In addition, numeral 39 in the figure is a starting aid capacitor. Next, the operation of the apparatus configured as described above will be described. Now, the AC power supply 21 is turned on, a DC output is generated by the rectifier circuit 23, and the bias resistors 29 and 30
When a base bias is applied to each transistor 27, 28 through the transistors 27, 28, one of the transistors 27, 28 turns on first due to a slight imbalance between the transistors 27, 28. A voltage is applied to the primary winding 25a of the output transformer 25, assuming that the temporary transistor 27 is now turned on, and this applied voltage generates a resonant voltage in the resonant circuit of the primary winding 25a and the capacitor 31.
This resonant voltage then generates a sinusoidal output in the feedback winding 25b of the output transformer 25, which turns off the transistor 27 and turns on the transistor 28. Thereafter, the above operation is repeated and transistor 2
The output transformer 25 is turned on and off by turns 7 and 28.
A high frequency AC output is generated in the preheating winding 2.
The discharge lamps 33,
34 filaments are preheated. In addition, the output of the secondary winding 25c causes the discharge lamp 3 to
3 and 34 are activated and illuminated with the effect of the conductor 38 described above. However, in order to find out the effect of the conductor 38 by connecting it to the common connection point of the discharge lamps 33 and 34 for such a device for lighting two lamps in series, data on the starting voltage was obtained through an experiment, and the following effect was confirmed. Ta. Table 1 shows the discharge lamp lighting device shown in Figure 3 and the same discharge lamp lighting device as in Figure 3 except that the connection between the conductor and the discharge lamp was made in the conventional manner as explained in Figure 2 Showing a comparison. In Table 1, the starting voltage is the input voltage when the high-frequency power converter outputs the high-frequency AC voltage for starting the discharge lamp, that is, the output voltage value (effective value) of the AC power source. In this case, a glow start type 40W fluorescent lamp (FL40S/W: manufactured by Toshiba) with a tube diameter of 32 mφ and using argon as the filled gas is used as the discharge lamp. In addition, the high frequency AC power supply device is one that outputs a high frequency AC voltage of 200V, 70KHz when an output of 100V from the AC power source is input, and the ratio of the input voltage value to the output voltage value is twice. .

[Table] Similarly, a discharge lamp with a tube diameter of 29.5 m using argon as the filler gas and Cryprint
This is a high frequency AC power supply device that uses a 40W φ glow start type fluorescent lamp (FL40S/W/38: manufactured by Toshiba) and outputs a high frequency AC voltage of 240V, 70KHz when an AC power output of 100V is input. , the ratio of input voltage value to output voltage value is 2.4
When twice the amount was used, the following results were obtained.

[Table] As a result, as is clear from Tables 1 and 2, according to the present invention, the starting voltage (input voltage of the high frequency power converter) when lighting two lamps in series is approximately 10V or more compared to the conventional one. It was confirmed that the output of the high-frequency AC power supply could be reduced by 15 to 16V, and by about 20V or 36 to 38V. This makes it possible to always stably perform the lighting operation of the discharge lamps when two lamps are lit in series, but it also makes it possible to lower the output voltage of the high frequency AC power supply device. It has been confirmed through experiments that similar results can be obtained as long as the high-frequency AC device outputs a high-frequency AC voltage of several KHz or more, and that the current limiting element is not limited to a capacitor. It should be noted that the present invention is not limited to the above-mentioned embodiments, but can be implemented with appropriate modifications within the scope without changing the gist.
For example, in the above description, the conductor is provided along the discharge lamp, but the metal case housing the discharge lamp may also serve as the conductor. Furthermore, a conductive portion formed by coating the discharge lamp itself may be used as the conductor when one lamp is lit. Furthermore, although the case of lighting two lights in series has been described above, it can also be applied to lighting with three or more holes in series. Further, the conductor may be grounded. As described above, according to the present invention, it is possible to reduce the starting voltage of the discharge lamp, and as a result, it is possible to provide a discharge lamp device for lighting multiple lamps in series, which can be expected to achieve stable lighting and a reduction in the output voltage of the high-frequency AC power supply device.

[Brief explanation of the drawing]

1 and 2 are schematic configuration diagrams showing a conventional discharge lamp lighting device, respectively, and FIG. 3 is a circuit diagram showing an embodiment of the present invention. A1, A2, A3...High frequency AC power supply device, 1,
11, 21... AC power supply, 2, 12, 22... High frequency power converter, 3, 13, 25... Output transformer,
5, 15, 16, 33, 34...Discharge lamp, 8, 1
7, 38...Conductor.

Claims (1)

[Scope of Claims] 1. A high-frequency AC power supply device, a plurality of discharge lamps connected in series that are lit by the high-frequency AC output of the current device, and a plurality of discharge lamps arranged along the discharge lamps and connected in series. A discharge lamp lighting device comprising: a conductor connected to any one common connection point of the discharge lamp. 2. The discharge lamp lighting device according to claim 1, wherein the conductor is made of a metal case that houses the discharge lamp. 3. The device for lighting a discharge lamp according to claim 1, wherein the conductor includes a conductive portion that is coated on the discharge lamp.