JPS5866292A - Device for firing discharge lamp - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a discharge lamp lighting device for lighting a metal halide high-pressure discharge lamp in which a 〇 compound is enclosed in a metal iodide.

Figure 1 shows a conventional discharge lamp lighting device for lighting a so-called metal pallite discharge lamp in which iodide-based metal halides are sealed using a ballast (1) that constitutes a low-frequency lighting circuit using a leakage transformer. This circuit is shown below.The metal pallite discharge lamp (2) is, for example, a mercury lamp with metal halides added, and has high efficiency characteristics.The reason why metal halides are used is that quartz The main points to mention are ζ7, which does not adversely affect the arc tube, high vapor pressure, and greatly increasing the amount of metal elements contained in the mercury arc. L11 Indium In
(vapor pressure of) and iodides (TJI, LII,
It is known that the vapor pressure of In'Is) becomes significantly high, and a higher vapor pressure in a discharge tube means higher efficiency.In general, metal halides include iodides and bromides. , chlorides, fluorides, etc., but stable iodides are used in discharge lamps.

When lighting the metal pallite discharge lamp (2) using the circuit shown in wi1, the lamp goes through the following process. In other words, when the low frequency power source (3), which is a commercial power source, is turned on, the discharge lamp (
If the discharge lamp (2) is a mercury lamp, for example, the secondary voltage of the ballast +1) is applied to both ends of the lamp (2), and immediately after starting, the lamp voltage ■l shows a very low value of about 10/-20V. However, as the temperature of the arc tube rises, the lamp voltage V increases, and over time, it reaches the rated voltage and becomes stable. In general, the re-ignition voltage ■-p is low when the pump pressure 1/j is low, but in high-pressure discharge lamps containing iodide (so-called metal halide lamps), there is an excess of iodine, and free iodine is generated. Immediately after starting due to iodine, the restriking voltage v
A phenomenon occurs in which the top p rises abnormally. Discharge lamp (2
) The metal iodides sealed in the lamp include thallium iodide and sodium iodide, which dissociate at the temperature of the arc center and produce high-pressure metal vapor, making discharge lamps with higher luminous efficiency than mercury lamps. These metal vapors react with iodine again near the wall of the arc tube, returning to the original iodide. By the way, the vapor pressure of the metal iodide itself is very low at room temperature, but if the recombination reaction of iodine is incomplete and free iodine remains, the electron emission table of the electrode I
In addition to adhering to Ivt and having a negative effect on electron emission,
Since iodine exhibits a high vapor pressure at room temperature, it significantly increases the restriking voltage vn- immediately after starting. (After a certain period of time, the restriking voltage Vj,p due to iodine disappears.) The magnitude of this restriking voltage Vj, , varies depending on the inclusions, structure, lighting circuit, etc., and the N@-Tj-1n system discharge lamps have a queen-like phenomenon, but discharge lamps with Nm -S (H system added as iodide) tend to have a higher increase in v!-9 (efficiency (high) This is due to the influence of iodine, as Sc reacts with the quartz in the arc tube, and Sl is liberated and adheres to the electrodes, making it worse.Also, as the arc tube becomes smaller, these phenomena become even more magnified. Ru.

Figure 9g2 is a waveform diagram showing the above-mentioned phenomenon of restriking voltage Vj-p. indicates the lamp voltage VJ immediately after starting, and at this time the discharge lamp is almost in a short circuit state (10-20V). EoQ indicates the lamp voltage Vi several seconds after starting, and at this time, the re-ignition voltage vi -p increases abnormally. Figure (b) shows the lamp voltage V! during stable lighting.The waveform shown in Figure 2, 09, occurs several seconds after starting, from several tens of seconds to several minutes.

By the way, conventional metal halide discharge lamps (2) have the above-mentioned problems, so a ballast with 9 + 11 double-coal thermal load voltages vo is used to prevent them from being turned off due to the restriking voltage vi-p. It is necessary to set a high value, especially in a low capacity discharge lamp (2), when the ballast +'t>0 secondary coal heating voltage V
When I raised o, the ballast (1) became larger.

The present invention has been made in view of the above-mentioned problems, and its purpose is to prevent the adverse effects of free iodine and reduce the re-ignition voltage during the period from starting to steady lighting of a discharge lamp. To provide a discharge lamp lighting device in which the ballast can be made smaller and the effective value of the high frequency power supply voltage can be kept low.

The present invention will be explained below with reference to Examples. In FIG. 3, 14) is 1lI61'I! llKdenrinderoruoCmr
X'? A capacitor for limiting the current of the source +41, and the capacitance of the capacitor C@ is selected so that it has a high impedance to the low frequency power source (commercial power source).No. Figure 6) and (b) are pulsating current waveforms that increase the two-coal thermal load voltage voh of the ballast (1) and the no-load voltage vHF of the high-frequency power supply (4) to a high voltage near the 9G' phase of the cycle. It is. Therefore, the high frequency voltage V is applied to the secondary voltage of the ballast (1).
At is superimposed, and this superimposed voltage is in phase with the voltage of the low-frequency power supply (3) and has a pulsating waveform, so that the high-frequency voltage VHF is at the phase where the restriking voltage Vj, is the highest in the starting period. Maximum value and auction, restriking voltage vJ immediately after starting
−, K can be prevented from turning off due to high frequency power supply (4
) can keep the effective value of the no-load voltage VIP low. In other words, in the conventional circuit shown in FIG.
p (shown in Figure 09 of tlI2) is considered to be the result of the synergistic effect of the lamp current being near zero, that is, the lamp equivalent tuftance being extremely low, and the effects of free iodine, but the above-mentioned In the circuit shown in Figure 3, the high-frequency peeking power from the high-frequency power source (4) is supplied at the same time as the lamp (2) starts (the low-frequency power source (3) is turned on), so the low-frequency source (3) Even near zero DC,
By supplying current from the high frequency power source 4), it is possible to prevent the adverse effects of the free iodine mentioned above, resulting in an extremely high re-ignition voltage vt-p during the period from starting to steady lighting of the discharge lamp (2). SS In the case of the circuit shown in Figure 1, L
/2-1/3.

FIG. 5 shows a circuit block diagram of an embodiment based on the basic circuit of FIG. 3, and FIG. 6 shows! High frequency power supply 14 of g5 diagram circuit
) is shown below. The ballast +11 uses the same delayed phase ballast as the circuit in Figure 1, and the high frequency power source 14) uses a wave power source (3).
is rectified by a full-wave rectifier DB, and the pulsating current is passed through the primary windings of 7 oscillation transformers O and T to transistors Q+, respectively.
, Og is applied between collector-emitter 1, transformer T
The voltage is stepped down by the transistor Ql, Q! It is designed to flow through starting resistors R, , R, to the base of .

Therefore, when the low frequency power supply (3) is turned on now, the secondary voltage VOz of the ballast +1) shown in Fig.
) is applied to both ends. At the same time, one of the transistors Q+ and Qt turns on first due to a slight imbalance in the circuit constants of the transistors Qr and Q in the high frequency power supply 4). If the transistor QL were to turn on, current would flow through the primary windings N1 of the oscillation transformers O and T, which would cause the interference between the windings of the oscillation transformers O and T and the vibration of the resonant circuit of the oscillation compressor C. The voltage generates a back electromotive force in the base feedback winding II Ng, and the transistor Q+
, Qt are turned on and off alternately, and the oscillation transformer O0T 2
A pulsating high frequency pressure VIF shown in FIG. 7(D) is generated at both ends of the next volume SN, and 〕〕ーー! :This high frequency voltage VHν is applied to both ends of the discharge lamp (2) together with the voltage Vo mentioned above via the CI. The discharge lamp (2) starts discharging with these voltages, but the high frequency voltage Vu
The restriking voltage V in the starting period is determined by sr as in the conventional case.
The abnormal rise in z-p is suppressed, and as a result, the discharge lamp (2
) lamp voltage Vz becomes as shown in Figure 7 (l Load-pressure V
This means that it is possible to lower O2 compared to the fJ1 diagram circuit. On the other hand, immediately after starting the scattering lamp (2), the lamp voltage vj
The voltage is as low as 10 #20Vs, and it becomes a state that can be called a short circuit state.

If the ballast f1) is a slow phase type, the phase will be delayed by nearly 90' with respect to the voltage of the low frequency power supply (3), so the restriking voltage v
t-p is near the highest phase of the high frequency voltage V11F. FIG. 8 is a diagram showing the temporal change of this re-ignition voltage V i -p, in which the solid line shows the magnitude of the re-ignition voltage V j-p of the circuit of FIG. 1 which is indicated by a broken line. It can be seen that the restriking voltage Vj-p of the circuit of this embodiment, shown by , is low. Now, the absolute value of the restriking voltage Vj-p and the high frequency voltage V
The phase relationship of the revisions is shown in Figure 9. In addition, the restriking voltage vz-p
, & is used as the absolute value because it is for commercial lighting, and the re-ignition voltage Vj-p crosses between positive and negative. Now, in Fig. 9, phase θ1 indicates a point several tens of seconds after starting,
Km is around the maximum value of the restriking voltage VZ-, shown by the solid line in FIG. Phase 6 indicates a phase in which the restriking voltage Vj-p has decreased, and the time t from phase θ1 to θ snow is from several tens of seconds to several minutes. Phase θ is the restriking voltage Vj during steady lighting
- pK, and the time to phase θ, or θ, is the warm-up time from startup to steady lighting, which is characteristic of metal pallite discharge lamps.Therefore, the restriking voltage Vi-p
The temporal change in the phase of is θ1→θ2→#. In other words, when the restriking voltage V1-p is the highest, the maximum value of the high frequency voltage VIF is applied to K, and therefore the ballast (
2) The two-coal heat load voltage VO can be lowered, and the power out at startup can be prevented by VHF K.

Incidentally, the rise in the re-ignition voltage V t -p from phase θt to θ is the lamp voltage V! This is due to the rise in the number of people.

The present invention is configured as described above, and the discharge lamp is lit by superimposing the high-frequency voltage of the high-frequency power supply on the low-quantity wave voltage applied to the discharge lamp via the ballast at least during the discharge lamp startup period. It is possible to suppress the abnormal rise in restriking voltage due to free iodine immediately after starting, and it is possible to lower the secondary no-load voltage of the ballast, so it is possible to reduce the size of the ballast. In addition, the pulse shape is in phase with the low frequency power supply voltage of commercial conduction.
7. Current Waveform Since a high wave voltage with a waveform having an envelope curve is applied to the discharge lamp along with a low frequency voltage, the highest voltage can be applied near the restriking voltage, especially when the lamp is not lit. Even at times, high wave voltage is superimposed on the secondary no-load voltage of the ballast, and the vicinity of its peak value is added, making it easy to obtain the voltage necessary for starting, thus keeping the Takaoka wave power supply voltage low. It has the effect of being

[Brief explanation of drawings]

Figure 41 is a circuit diagram of the conventional example, Figure 2 (i'') is a waveform diagram for explaining the operation of the same as above, Figure 3 is a circuit diagram of the basic circuit of the present invention, Figure 4 (@) (b) are the waveform diagrams of the same parts as above, No. 5
The figure is a circuit block diagram of an embodiment of the present invention, FIG. 6 is a specific circuit diagram of the high frequency power supply mentioned above, fiF57 diagram ωAC+Q is a waveform diagram for explaining the operation of the same, and FIG. 8 is the restriking voltage of the same mentioned above. FIG. 9 is an explanatory diagram showing the relationship between the restriking voltage and phase of the same as above; (1) is a ballast,
(2) is a discharge lamp, ]3) is a low frequency power source, and 14) is a high frequency power source. Agent Patent Attorney Ishi 1) Choshichi

Claims (1)

[Claims] (1) Iodide metal halogen... A discharge lamp lighting device that lights a metal halogen discharge lamp sealed with a compound, which is equipped with a low frequency power source such as a commercial power supply and a high frequency power source that generates a high frequency voltage, and is stable. A discharge lamp lighting device characterized in that a high frequency voltage of a high frequency power source is superimposed on a low frequency voltage applied to the discharge lamp via a discharge lamp at least during the starting period of the discharge lamp to light the discharge lamp.