JPH07272887A - Discharge lamp lighting device - Google Patents

Abstract

PURPOSE:To provide a discharge lamp lighting device having a constant luminous flux and capable of controlling color temperature. CONSTITUTION:A power source frequency conversion device 11 varies the frequency of a power source connected to respective lighting circuits to change the impedance of capacitive and inductive ballasts 9 and 10, and a high power source frequency relatively enlarges the luminous flux of an arc tube 1 on a mercury lamp side to which the capacitive ballast 9 is to be connected to change the luminous color of a discharge lamp 4 to a high color temperature side to obtain light having a refreshing sense. Conversely, a low power source frequency relatively enlarges the luminous flux of an arc tube 2 on a high pressure sodium lamp side to which the inductive ballast 10 is connected to obtain light of a warm color system having low color temperature.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a discharge lamp lighting device.

[0002]

2. Description of the Related Art Conventionally, as a discharge lamp lighting device, two high pressure discharge lamps having different emission colors are individually lit by a lighting circuit, and light emitted from both high pressure discharge lamps is mixed with each other as shown in FIG. The present inventors have proposed the above. This Figure 7
The discharge lamp lighting device shown in FIG. 1 has a combination of two high-pressure discharge lamps in which a high-pressure mercury lamp arc tube 1 having a different emission color and a high-pressure sodium trim lamp arc tube 2 are housed in the same outer tube 3. The discharge lamp 4 is used to light each of the arc tubes 1 and 2 by a lighting circuit provided separately.

The lighting circuit corresponding to the arc tube 1 is a current limiting circuit.
Inductance element L₁And the dimming inductance element L
₂And lighting switch S₁And a dimming inductance is required
Element L ₂Dimming switch S connected in parallel to₂With
The lighting circuit corresponding to the arc tube 2 is a current limiting inductor.
Coutance element L₃And the dimming inductance element L
_FourAnd lighting switch S₃And a dimming inductance is required
Element L₂Dimming switch S connected in parallel to_FourWith
Each of the arc tubes 1 and 2 has these lighting circuits.
It is connected to the AC power supply 8 via. 5 and 6 are bases, 7 is
It is a common electrode.

In this conventional device, the lighting switch S ₁ ,
When both S ₃ are on, the AC power source 8 is connected to each lighting circuit, and both arc tubes 1 and 2 light up. At this time, if both the dimming changeover switches S ₂ and S ₄ are turned on, only the current limiting inductance elements L ₁ and L ₃ limit the tube current flowing in the arc tubes 1 and 2. Lights 1 and 2 are lighted with a luminous flux of 100% of the rated value.

When both the dimming changeover switches S ₂ and S ₄ are turned off, the tube current flowing through the arc tubes 1 and 2 is limited by the series connection of the current limiting inductance element L ₁ and the dimming inductance element L ₂ . The impedance becomes a series impedance of the current-limiting inductance element L ₃ and the dimming inductance element L ₄ , and the arc tubes 1 and 2 are turned on with a luminous flux of 50% of the rated value.

Further, if either of the lighting switches S ₁ and S ₃ is turned off, the arc tube connected to the switch on the off side is turned off and the luminous flux becomes 0% of the rated value. In other words, the light emitting tubes 1 and 2 have the lighting switches S ₁ and S ₃ of the corresponding lighting circuits.
Also, the light flux can be set in three stages of 100%, 50% and 0% of the rating by the combination of ON / OFF of the dimming changeover switches S ₂ and S ₄ , and the light flux as the discharge lamp 4 is emitted from the arc tube 1, A dimming step as shown in Table 1 can be obtained by a combination of three light flux settings of two.

[0007]

[Table 1]

Moreover, since the optical characteristics (for example, color temperature, color rendering, etc.) of the respective arc tubes 1 and 2 are mixed, there is a feature that intermediate optical characteristics of the arc tubes 1 and 2 can be obtained.

[0009]

In the discharge lamp lighting device of FIG. 7, the optical characteristics can be changed in several steps, but in that case the total luminous flux also changes. Strictly speaking, it is possible to change the optical characteristics with a constant total luminous flux, but in this case, the total luminous flux is 50% of the rated value.
It is possible only when the output is reduced (marked with * in Table 1).

The present invention has been made in view of the above problems, and the invention of claim 1 has a constant luminous flux and a color temperature (optical characteristic).
Disclosed is to provide a discharge lamp lighting device capable of finely controlling.
The object of the invention of claim 2 is, in addition to the object of claim 1, to provide a discharge lamp lighting device capable of converting a luminous flux at a constant color temperature. The object of the invention of claim 3 is, in addition to the object of the invention of claim 1, that dimming is possible even when the color temperature is constant, and the color temperature can be changed in the dimming state. A discharge lamp lighting device is provided.

An object of the invention of claim 4 is to provide a discharge lamp lighting device capable of handling two high pressure discharge lamps as one discharge lamp in addition to the object of the invention of claim 1.

[0012]

In order to achieve the above object, the invention of claim 1 comprises a first lighting circuit constructed by connecting an inductive current limiting element to a first high pressure discharge lamp; A capacitive current limiting element is connected to a second high pressure discharge lamp that is different in color from the first high pressure discharge lamp and is arranged so that the emitted light is mixed with the light emitted by the first high pressure discharge lamp. Second configured
Lighting circuit, and a variable frequency power supply is connected to these first and second lighting circuits. According to a second aspect of the present invention, a lighting switch that can be turned on and off separately is inserted between each lighting circuit and the variable frequency power supply.

According to a third aspect of the present invention, each of the inductive current limiting element and the capacitive current limiting element is a current limiting element capable of dimming control. In the fourth aspect, the first and second high-pressure discharge lamps have respective arc tubes housed in the same outer tube.

[0014]

According to the first aspect of the present invention, the first lighting circuit configured by connecting the inductive current limiting element to the first high pressure discharge lamp and the first high pressure discharge lamp have different emission colors and A second lighting circuit configured by connecting a capacitive current limiting element to a second high pressure discharge lamp arranged so that the emitted light is mixed with the light emitted by the first high pressure discharge lamp. , These first and second
Since the variable frequency power supply is connected to the lighting circuit of 1, the color temperature (optical characteristics) can be changed arbitrarily and finely if the total luminous flux of the luminous flux of both discharge lamps is kept substantially constant.

According to a second aspect, in the invention of the first aspect,
Since a lighting switch that can be turned on and off separately is inserted between each lighting circuit and the variable frequency power supply,
It is also possible to change the luminous flux while fixing the color temperature.
According to a third aspect of the present invention, in the invention of the first aspect, since each of the inductive current limiting element and the capacitive current limiting element is a current limiting element capable of dimming control, the dimming state is maintained at a constant color temperature, or the same. The color temperature can be changed in the dimming state.

According to a fourth aspect, in the invention of the first aspect,
Since the first and second high-pressure discharge lamps house the respective arc tubes in the same outer tube, they can be treated as one discharge lamp.

[0017]

Embodiments of the present invention will be described below with reference to the drawings. (Embodiment 1) FIG. 1 shows the structure of this embodiment. In this embodiment, the arc tube 1 of a high pressure mercury lamp having a color temperature of about 4200K and the arc tube 2 of a high pressure sodium lamp having a color temperature of about 2000K are shown. Is used in the same outer tube 3 and a discharge lamp 4 having a combination of two high pressure discharge lamps is used. In this embodiment, a cap 5 corresponding to the arc tube 1 is provided with a capacitive ballast 9. A lighting circuit composed of a series circuit of the lighting switch S ₁ is connected, and a lighting circuit composed of a series circuit of the inductive ballast 10 and the lighting switch S ₃ is connected to the base 6 corresponding to the arc tube 2. .

The output of the power supply frequency converter 11 is connected between the other end of these lighting circuits and the common electrode 7 of the discharge lamp 4. The power supply frequency conversion device 11 is capable of continuously and arbitrarily varying the frequency f of the power supply applied to the lighting circuit using the AC power supply 8 as an input power supply. The capacitive ballast 9 is usually composed of a series circuit of an inductance element L ₁ and a capacitance element C, the inductive ballast 10 is composed only of an inductance element L ₃ , and the impedance Z of the inductive ballast 10 is a frequency. A positive characteristic with respect to f, that is, the impedance Z also increases as the frequency increases as shown in FIG. On the other hand, the relationship between the frequency f and the impedance Z of the capacitive ballast 9 is as shown in FIG. Since this is composed of a series circuit of an inductance element L ₁ and a capacitance element C, the reactance in the series circuit of LC is ωL ₁ −1 / ωC (ω = 2π
f) and when f ₀ = 1 / 2π√L ₁ C, ωL ₁
-1 / ωC = 0, the reactance becomes 0, and the impedance Z of the ballast becomes the minimum. However, f ₀ indicates a resonance frequency.

The capacitive ballast 9 is a ballast in which the value of the inductance element L _{1 and} the value of the capacitance element C are set on the assumption that the discharge lamp is lit at a frequency lower than the resonance frequency f ₀ . In other words, the impedance Z decreases as the power supply frequency increases. Here, in the embodiment, as described above, the arc tube 2 of the high-pressure sodium lamp is connected to the inductive ballast 10, the arc tube 1 of the mercury lamp is connected to the capacitive ballast 9, and the power supply frequency f is the predetermined frequency f ₁ At that time, the respective ballasts 9 and 10 are designed so that the luminous fluxes of both arc tubes 1 and 2 become substantially the same.

In this embodiment, when the power supply frequency f is higher than f ₁ , the luminous flux of the arc tube 2 on the high pressure sodium lamp side is lowered, whereas the luminous flux of the arc tube 1 on the mercury lamp side is reversed. Since it rises, the luminous flux of the entire discharge lamp 4 becomes substantially constant even if the power supply frequency f is changed. Conversely, when the power supply frequency f is lower than f _1, the luminous flux of the arc tube 2 on the high-pressure sodium lamp side rises contrary to the above, whereas the luminous flux of the arc tube 1 on the mercury lamp side decreases conversely. The luminous flux of the entire discharge lamp 4 is kept substantially constant.

From the above results, the lighting switches S ₁ and S
_The power supply frequency f connected to the lighting circuit by the power supply frequency converter 11 is f ₁ shown in FIG.
If it is made higher, the luminous flux Φ ₁ of the arc tube 1 on the mercury lamp side becomes relatively large, and the emission color changes to a higher color temperature Tc, as shown in FIG. 5, and light with a refreshing feeling can be obtained. . On the contrary, if the power supply frequency f connected to the lighting circuit by the power supply frequency converter 11 is made lower than f ₁ , the luminous flux Φ ₂ of the arc tube 2 on the high pressure sodium lamp side becomes relatively large, and the warm color with a low color temperature Tc is obtained. The light of the system will be obtained.

As described above, in this embodiment, the power source frequency converter 11 continuously varies the power source frequency f to keep the total luminous flux Φ ₃ of the discharge lamp 4 constant as shown in FIG. Tc can be continuously and arbitrarily changed as shown in FIG. 5, which is an effective means for production illumination and the like. In this embodiment, the discharge lamp 4 in which the arc tube 1 of the mercury lamp and the arc tube 2 of the high-pressure sodium lamp are housed in the same outer tube 3 is used. Two
It is not inevitable that the lamp must be stored, and independent high-pressure sodium lamp and mercury lamp may be used respectively. Further, the type of the lamp is not particularly limited to the high pressure natriun lamp and the mercury lamp, and two high pressure discharge lamps of different emission colors may be arranged so that the lights of both discharge lamps are mixed.

(Embodiment 2) In Embodiment 1, two arc tubes 1,
2 are turned on at the same time, the total luminous flux Φ ₃ is constant, and the color temperature is Tc.
However, it is not always necessary to light the two arc tubes 1 and 2 (two types of high pressure discharge lamps) at the same time, but only one arc tube (one high pressure discharge lamp) By turning on the light and changing the power supply frequency f, the color temperature T
It is also possible to control that the total luminous flux Φ ₃ is changed with a constant c.

In this embodiment, the color temperature Tc is constant and the total luminous flux Φ is
_Since the circuit configuration shown in FIG. 1 is used, the lighting switch S ₁ and S ₃ are individually turned on and off independently. Using the one that can be made
It is possible to use only the arc tube 1 on the mercury lamp side, the arc tube 2 on the high pressure sodium lamp side, or the case where both arc tubes 1 and 2 are turned on as in the first embodiment. You can choose to.

(Embodiment 3) This embodiment enables dimming control while keeping the color temperature substantially constant as compared with Embodiment 1, and as shown in FIG. Tube 1
Mouthpiece of the arc tube 2 parallel circuits connect, also high-pressure sodium lamp with a capacitive current limiting element 9 'and dimming switching switch S ₂ for dimming between the base 5 and the capacitive ballast 9 6 and the inductive ballast 10 between the inductive current limiting element 10 'for dimming
Differs from the first embodiment in that connecting the parallel circuit of a preparative dimming switching switch S _4. In FIG. 6, circuit components having the same configuration and role as the circuit components of FIG. 1 are designated by the same numbers or symbols.

Thus, in this embodiment, the lighting switch S ₁ ,
Both S ₃ are turned on and the dimming changeover switch S ₂ ,
Both S ₄ are turned off, the output frequency of the power supply frequency converter 11, that is, the power supply frequency f is fixed to a predetermined frequency, for example, f ₁ and both arc tubes 1 and 2 are turned on to switch the dimming control. If both switches S ₂ and S ₄ are turned off,
Current limiting elements 9'and 10 'for dimming the respective ballasts 9 and 10.
Are connected in series, the tube current flowing through both arc tubes 1 and 2 is reduced, and the luminous fluxes Φ ₁ and Φ ₂ are both reduced. Here, for the fixed frequency, both current limiting elements 9 ',
If the impedance Z of 10 'is designed to be the same, the luminous flux drop of both discharge lamps 9'10' will be the same,
Therefore, the color temperature Tc does not change, and the total luminous flux Φ ₃ is lowered to enter the dimming state.

Further, in this dimming state, if the output frequency of the power source frequency converter 11, that is, the power source frequency f, is changed, the impedance Z of the series circuit of the ballast 9 and the current limiting element 9'and the ballast 10 are connected. The impedance Z of the series circuit with the current limiting element 10 'changes in the directions opposite to each other, and the luminous fluxes of both arc tubes 1 and 2 become relatively separated from each other, and when the power supply frequency f is increased, light is emitted. Color is color temperature T
When the power supply frequency f is lowered, the emission color changes to a lower color temperature Tc. That is, the color temperature Tc can be converted without changing the dimming state.

[0028]

According to the first aspect of the present invention, the first high-pressure discharge lamp is connected to the inductive current limiting element, and the first high-pressure discharge lamp has a different emission color. A second lighting circuit configured by connecting a capacitive current limiting element to a second high pressure discharge lamp arranged so that the emitted light is mixed with the light emitted by the first high pressure discharge lamp. , These first and second
Since a variable frequency power supply is connected to the lighting circuit of, the color temperature (optical characteristics) can be changed arbitrarily and finely if the total light flux of the light fluxes of both discharge lamps is kept almost constant. It has the effect that it can be used effectively.

According to a second aspect of the present invention, in the first aspect of the present invention, each of the lighting circuits and the frequency variable power source are individually turned on,
Since each of the lighting switches that can be turned off is inserted, it is possible to change the luminous flux while fixing the color temperature. According to the invention of claim 3, in the invention of claim 1, since each of the inductive current limiting element and the capacitive current limiting element is a current limiting element capable of dimming control, the dimming state is maintained at a constant color temperature, Alternatively, there is an effect that the color temperature can be changed in the same dimming state.

According to a fourth aspect of the invention, in the first aspect of the invention, the first and second high-pressure discharge lamps have respective arc tubes housed in the same outer tube, and therefore can be treated as one discharge lamp. The effect is that you can.

[Brief description of drawings]

FIG. 1 is a circuit configuration diagram of a first embodiment.

FIG. 2 is a characteristic diagram showing the relationship between the impedance of the above-described capacitive ballast and the power supply frequency.

FIG. 3 is a characteristic diagram showing the relationship between the impedance of the inductive ballast and the power supply frequency in the above.

FIG. 4 is a characteristic diagram showing a relation between a luminous flux of both arc tubes and a total luminous flux of a discharge lamp and a power supply frequency.

FIG. 5 is a characteristic diagram showing the relationship between the color temperature of the discharge lamp and the power supply frequency in the above.

FIG. 6 is a circuit configuration diagram of the first embodiment.

FIG. 7 is a circuit configuration diagram of a conventional example.

[Explanation of symbols]

1 arc tube 2 arc tube 3 outer tube 4 discharge lamp 5 cap 6 cap 7 common electrode 8 AC power supply 9 capacitive ballast 10 inductive ballast 11 power frequency converter S ₁ lighting switch S ₃ lighting switch

Claims (4)

[Claims] 1. A first lighting circuit configured by connecting an inductive current limiting element to a first high pressure discharge lamp, and a light emitting color different from that of the first high pressure discharge lamp and emitting light. A second lighting circuit configured by connecting a capacitive current limiting element to a second high pressure discharge lamp arranged so as to be mixed with the light emitted from the high pressure discharge lamp, and A discharge lamp lighting device, comprising a variable frequency power supply connected to the lighting circuit. 2. The discharge lamp lighting device according to claim 1, wherein a lighting switch that can be turned on and off separately is inserted between each lighting circuit and the variable frequency power supply. 3. The discharge lamp lighting device according to claim 1, wherein each of the inductive current limiting element and the capacitive current limiting element is a current limiting element capable of dimming control. 4. The discharge lamp lighting device according to claim 1, wherein the first and second high pressure discharge lamps have respective arc tubes housed in the same outer tube.