JPH0570279B2 - - Google Patents

Description

Detailed Description of the Invention [Technical Field] The present invention relates to a discharge lamp lighting device for lighting a fluorescent lamp at high frequency.

[Background Art] In recent years, in order to make lighting devices smaller, lighter, and more efficient, lighting circuits have been made to operate at higher frequencies, and fluorescent lamps that operate at high frequencies have become popular and established.

As an example of this lighting circuit, one that first obtains DC power from a commercial power source, converts the DC power of this DC power source into a high frequency using a high frequency conversion circuit, and lights a fluorescent lamp with the high frequency power is widely available.
Furthermore, the preheating and starting circuits have been designed to extend the lifespan of fluorescent lamps. As for the frequency, a high frequency of 20KHz or higher is usually used to make it smaller, lighter, and less noisy. The fluorescent high-frequency lighting device configured and designed in this way is an energy-saving lighting device that aims to save electricity, and if it can provide the same brightness as lighting at a commercial frequency (50/60Hz). In this case, the lamp current is at a high frequency, so there is less power loss due to the fall of the filament electrode of a fluorescent lamp, so the lamp current is lower than when lighting at a commercial frequency, and the same luminous flux is achieved. can be produced. However, there is a bias toward emphasizing power saving models, and brightness (total luminous flux)
The number of fluorescent lamps has to be increased unnecessarily in order to achieve the brightness that meets the illuminance needs of consumers, and as a result, the number of installed fixtures and the dimensions of the fixtures have increased, resulting in various inconveniences in terms of construction, design, economics, etc. It was exhibiting.

On the other hand, high-frequency lighting fixtures are available for residential use that aim to increase the brightness (total luminous flux) by setting the lamp current to almost the same as that when lighting at a commercial frequency. In this case as well, the lamp current during high-frequency lighting is set to be approximately the same as the lamp current during rated lighting at commercial frequency, so the brightness (total luminous flux) increase will be higher than the total luminous flux during rated lighting at commercial frequency. It has been confirmed by actual measurements that if it is 100%, it is at most 15% or less. However, it varies depending on the type of fluorescent lamp and whether or not there is a pause period in the lamp current. For this reason, it has not been possible to meet consumer demands for a smaller lighting fixture with a large total luminous flux. In other words, in the case of a FL20 6-lamp lighting fixture, it is used for a residential area of 8 to 10 tatami mats, but the above 15%
When the luminous flux increases, 5.2 fluorescent lamps are required, and 5.
The lamp does not provide the desired total luminous flux. In the end, we ended up using 6 lights, which increased the brightness a little, but
Unlike light fixtures, the size of the fixtures was not small, and the design of the fixtures was not effective.

As an improvement, it may be possible to replace 0.2 of the 5.2 lights with a single FL10 fluorescent light, but this poses the problem that when looking at the lighting equipment from the outside, the light emission lengths are different, making it seem strange. Unfavorable appearance when lit. Moreover, even when two types of high-frequency lighting devices, FL20 and FL10, are provided, or when the high-frequency output of one type of high-frequency lighting device 1 is turned on all at once via a balancer 3, as shown in FIG. ₂₀₁ ~ 2 An impedance element 4 equal to the difference between the impedance of ₂₀₅ and the impedance of _FL10 fluorescent lamp 2 is connected to the fluorescent lamp 2 of FL20 ₂₀₁ ~ 2 ₂₀₂ and FL10
It is necessary to insert it into a series circuit with the fluorescent lamp 2 ₁₀ or use a special balancer that adds the function of an impedance element 4 to the balancer 3. In either case, the number of parts increases and the cost increases. There are drawbacks. The commercial power source AC is rectified by a full-wave rectifier 5 and smoothed by a smoothing capacitor 6 to be converted into a DC power source, which serves as a driving power source for the high-frequency lighting device 1.

By the way, when applied to a chandelier that uses metal or glass equipment components to create a sense of luxury and solidity, for example, if a chandelier with 6 FCL20 lights is reduced to 5 lights, the weight can be reduced by that amount. Although this effect is highly anticipated, conventional lighting systems have not been able to meet these expectations.

In addition, Figures 7 and 8 are FCL40 fluorescent lamps ₂₄₀ ,
A conventional 3-lamp series lighting circuit that sets the high-frequency lamp current value to obtain the same luminous flux as the total luminous flux when the FCL32 fluorescent lamp 2 ₃₂ and FCL20 fluorescent lamp 2 ₂₀ is lit at a commercial frequency, the balancer 3, and the preheating transformer. 7 and a preheating switch SW turned on during preheating are used to separately light two fluorescent lamps 2 ₂₀ and 2 ₃₂ and one fluorescent lamp 2 ₄₀ .
These conventional examples can reduce weight compared to using copper-iron type ballasts, but the number of fluorescent lamps is the same as when operating at commercial frequency, so the labor required to replace lamps and the use of fluorescent lamps are reduced. Costs etc. will not be improved.

[Object of the Invention] The present invention has been made in view of the above-mentioned problems, and its purpose is to save power without affecting the lifespan, and to efficiently light a discharge lamp to provide bright light. In order to increase the luminous flux (total luminous flux),
Furthermore, the present invention provides a discharge lamp lighting device that can realize a compact and lightweight device.

[Disclosure of the Invention] Embodiment Figure 1 shows a fluorescent lamp 2 made of _FCL32 and an FCL40.
This figure shows an embodiment circuit according to the method of the present invention in which a fluorescent lamp ₂₄₀ consisting of a fluorescent lamp 240 is connected in a two-lamp series circuit and the output of an oscillation transformer T of a high frequency lighting device 1 consisting of an inverter circuit is applied to light the fluorescent lamp 240. The secondary output of the preheating transformer 7 is connected to the filament electrode on the common connection side of 2 ₃₂ and 2 ₄₀ , so that preheating can be performed. A high frequency output is connected to the primary side of the preheating transformer 7 via the preheating switch SW and the filament electrodes on the power supply side of each of the fluorescent lamps 2 ₃₂ and 2 ₄₀ , and preheating is performed when the preheating switch SW is turned on. The DC power source for the high frequency lighting device 1 is obtained by rectifying and smoothing the AC power source using a rectifier circuit 5 and a capacitor 6. However
Using two fluorescent lamps 2 ₃₂ and 2 ₄₀ of FCL32 and FCL40, try to obtain the same brightness (total luminous flux) as when three lamps of FCL40, FCL32, and FCL20 are turned on at commercial frequency. This is the case in this embodiment.

Here, FCL32 and FCL40 used in this example are
We measured the relationship between the lamp efficiency lm/W and luminous flux when lit at a high frequency of 40KHz in an atmosphere of 20 _℃ , and the high frequency lamp current value _I Second
The results shown in the figure were obtained. In Fig. 2 _, the horizontal axis shows the high-frequency lamp current value _I It is expressed as a relative value using time as a reference (reference value η _OAC ). Furthermore, the luminous flux is also the same. As shown by curve A in this figure, the lamp efficiency lm/W of FCL32 peaks at 0.95×I _OAC , and the lamp efficiency of FCL32 peaks at 0.95×I OAC.
The peak efficiency of the lamp, lm/W, is around 0.85×I _OAC , as shown in curve (b). If the high frequency lamp current value is increased here, the lamp efficiency lm/
The point where W decreases and becomes exactly equal to the lamp efficiency lm/W when lit at commercial frequency is
The case of FCL32 is I _naxHF32 , and the case of FCL40 is
If I _naxHF40 , I _naxHF32 is around 1.3×I _OAC ,
It can be seen that I _naxHF40 is around 1.35×I _OAC . On the other hand, the luminous fluxes of FCL32 and FCL40, as shown by the curves C and D, gradually tend to saturate as the lamp efficiency lm/W decreases as the high-frequency lamp current value _I .

The following can be said from the measurement results shown in FIG.
In _{other words} , if the high-frequency lamp current _{value I} A power-saving lighting circuit can be created.

However, the brightness equivalent to when three lights of FCL40, FCL32, and FCL20 are turned on at commercial frequency is the first.
If you try to obtain it using the circuit shown in the figure, the luminous flux will increase by 23%.
The high frequency lamp current value I _XHF at that time
is 1.17×I _OAC , and in this example circuit, the circuit constants of the high-frequency lighting device 1 are adjusted to obtain _a high-frequency lamp current value _I The number of pieces is 1
This will allow you to reduce the number of books.

When the present inventors investigated the lamp life, which is a problem here, the results shown in FIG. 3 were obtained. This figure 3 shows a cycle of 5 sets of 2 lights, FCL40 and FCL32, turned on for 2.5 hours and turned off for 0.5 hours at room temperature. The graph shows the results of a lifespan investigation when the lamp is turned on by opening the preheating switch SW (after the preheating time), and the horizontal axis is the high-frequency lamp current value _I In the figure, A indicates the case when the high-frequency lamp current value I _XHF is 1.0×I _OAC , B indicates the case when the high _{- frequency} lamp current value I respectively show the case where the high frequency lamp current value _IXHF is 1.2×I _OAC . From this figure 3 _, if the high-frequency lamp current value I _XHF is the same as the rated lighting at commercial _frequency , that is, I It was found that this is more than twice as long as the filament electrode breakage life. This is because the circuit of the embodiment shown in FIG. 1 uses a direct current power source with almost no pulsations, which is obtained by rectifying the commercial power AC with a full-wave rectifier 5 and completely smoothing it with a smoothing capacitor 6. It is a complete advance preheating method that turns on the preheating switch SW at the time of startup, allows sufficient preheating, and then turns it off to turn on the light. This is the result of a combination of factors such as preheating, lowering the starting voltage applied to the minimum, and completely cutting off preheating during lighting, which lowers the spot temperature of the filament electrode and has a positive effect on lifespan. It is estimated that

As a result, the high frequency lamp current value I _XHF is higher than the rated lamp current value I _OAC when operating at commercial frequency ( _I
1.0×I _OAC ), the lamp life is expected to be sufficiently the same as the life when operating at a commercial frequency, and the results are also shown in Figure 3.

Here, the high frequency lamp current value set in the example
The value of _IXHF (1.17×I _OAC ) is a value that is satisfactory from the above-mentioned viewpoint of life.

Figures 4a and 4b show a lighting fixture A ₁ suspended by a cord C according to this embodiment and a lighting fixture A ₂ according to a conventional example of commercial frequency lighting. While the height of the shade D of the example appliance is H, the shade D of this example has a height h that is almost lower due to the fluorescent lamp ₂₂₀ of the FCL20, allowing for miniaturization. In addition, in the conventional example, each fluorescent lamp 2 ₄₀ ,
Copper iron type ballasts B ₄₀ , B ₃₂ , for 2 ₃₂ and 2 ₂₀ respectively.
Although it is heavy due to the use of _B20 , in this embodiment, not only the high frequency lighting device 1 is light but also the weight can be further reduced by reducing the number of fluorescent lamps and the accompanying reduction in supporting metal fittings. In addition, the reduction in the number of fluorescent lamps reduces costs, and the time and effort required to replace lamps is reduced by 2/3.
In addition, by setting the lamp efficiency lm/W higher than when lighting at a commercial frequency, it is possible to conserve power and reduce power consumption costs, resulting in a reduction in maintenance costs.

By the way, from the characteristics shown in Figure 2, if you want to obtain the brightness of 5 FCL32 fluorescent lamps lit at commercial frequency by lighting 4 lamps at high frequency, the high frequency lamp current value I _XHF will be 1.15 × I _OAC . The circuit constants of the high-frequency lighting device 1 were set so that the same effect as in Example 1 was obtained.

The above examples were examples using FCL40 and FCL32 fluorescent lamps, but it is generally said that the smaller the fluorescent lamp (lower wattage), the greater the effect of filament electrode loss, and therefore the higher the luminous flux increase rate. ing. Furthermore, in most types of fluorescent lamps, the lamp efficiency peaks at lm/W at a high frequency lamp current value _IXHF which is lower than the rated lamp current value _IOAC when operating at a commercial frequency.
Therefore, if the characteristic diagram of FIG. 2 is generally redrawn using average values including other types of fluorescent lamps, it becomes as shown in FIG. 5. As can be seen from the luminous flux curve A in this figure, the increase in luminous flux deviates from a linear increase and tends to saturation approximately around the point of 1.1×I _OAC .
In the case of FCL32, this trend is shown as can be seen in Figure 2, but in the case of FCL40, although it is slightly higher, it is safe to say that it is approximately 1.1 × I _OAC .

On the other hand, the luminous flux in this case of 1.1×I _OAC has meaning from another perspective. In other words, 1.1×I _OAC can be obtained with a luminous flux increase in the range of 15% to 20%. This is the value that can be used to reduce the number of fluorescent lights by one by using high-frequency lighting. Generally, the maximum number of lights in residential lighting equipment is six lights, and five or less lights are common.
Currently, this number of lights is determined due to the size of the room, dimensional constraints due to the interior design of the lighting equipment, and ease of construction.

Therefore, by using fluorescent lamps of the same type (same wattage), the number of lamps lit when lit at commercial frequencies can be reduced by high-frequency lighting, and by using fluorescent lamps of different types (different wattage).
The high frequency lamp current value _I
×I It settles around _OAC .

In addition, as a power-saving lighting method, the high frequency lamp current value I _XHF must be set to a value equal to or less than _InaxHF , so the resulting high frequency lamp current value I _XHF is constrained as follows.

1.1 _× I _OAC ≦I _XHF ≦ _{I naxHF} ... However _{, I}
As the value approaches , the total luminous flux increases at the expense of the lamp life, so if this point is taken into consideration, the high frequency lamp current value I _XHF can be expressed as follows.

_I
Ia. Therefore, in consideration of the lamp life, it is necessary to adopt a high frequency lamp current value I _XHF that satisfies both the following equations.

Furthermore, when a pulsating current power source obtained by full-wave rectification or a pulsating DC power source is used as the drive power source for the high-frequency lighting device 1, a pause section occurs in the lamp current, so the lamp efficiency lm/ as shown in FIG. The entire curves B and B of W and luminous flux move downward, and as the pulsation increases, the setting range of the high frequency lamp current value I _XHF becomes narrower.
Although the life of the lamp is shortened due to stress on the filament electrode, it goes without saying that this does not impede the object of the present invention in any way.

Furthermore, it goes without saying that the DC power supply is not limited to the one shown in the embodiments, and may be of any type (for example, a DC power supply using a chopper circuit, etc.).

[Effects of the Invention] As described above, the present invention includes a DC power source created by rectifying and smoothing a commercial power source, a high-frequency inverter that converts the voltage of the DC power source into high-frequency alternating current, and an output power source using the output of the high-frequency inverter. In a single-spot lighting type discharge lamp lighting device that is equipped with a discharge lamp that is powered, the value of the high-frequency lamp current flowing through the discharge lamp is I _XHF , the value of the rated lamp current when lighting at a commercial frequency is I _OAC , This rated lamp current
If I _naxHF is the value of the lamp current when it becomes equal to the luminous efficiency when lighting at a commercial frequency using I _OAC , then 1.1×I _OAC ≦I _XHF ≦I _naxHF However, since I _XHF <1.3×I _OAC , the The lamp efficiency allows fluorescent lamps to be lit and the total luminous flux to be significantly increased, making it possible to reduce the number of fluorescent lamps required in conventional lighting equipment and obtain the same total luminous flux. This has the effect of saving power, and by reducing the number of lights, the lighting equipment can be made smaller, lighter, and cheaper, and maintenance costs can be reduced.

Also, if you set the lamp current as described above,
The light output can be increased without the need for circuit changes, and the lamp life is not affected, and the efficiency of the lamp is better than that of commercial lighting.

[Brief explanation of the drawing]

FIG. 1 is a circuit diagram of Embodiment 1 according to the method of the present invention,
Figures 2 and 3 are explanatory diagrams of the same as above, Figures 4a and b
is a comparative explanatory diagram of the same as above and a conventional example, FIG. 5 is an explanatory diagram of a general example of the present invention, and FIGS. 6 to 8 are circuit diagrams of conventional examples, 1 is a high frequency lighting device, 2 is a fluorescent lamp. ,, I _OAC is the rated lamp current value when operating at a commercial frequency, and I _XHF is the high frequency lamp current value.

Claims (1)

[Claims] 1. A DC power source created by rectifying and smoothing a commercial power source, a high-frequency inverter that converts the voltage of this DC power source into high-frequency alternating current, and a discharge lamp energized by the output of this high-frequency inverter. In a discharge lamp lighting device with a single spot lighting method,
The value of the high-frequency lamp current flowing through the discharge lamp is I _XHF ,
The value of the rated lamp current when lit at commercial frequency is
I _OAC , If the value of the lamp current when the rated lamp current I _OAC becomes equal to the luminous efficiency during commercial frequency lighting is I _naxHF , then 1.1×I _OAC ≦I _XHF ≦I _naxHF However, I _XHF <1.3× I A discharge lamp lighting device characterized by _{an OAC} .