JPH06267678A - Discharge lamp lighting device - Google Patents

Abstract

PURPOSE:To turn an abnormal discharge lamp out, and concurrently turn the other discharge lamp on as well as to make constitution simple and small in size with cost lowered. CONSTITUTION:When a discharge lamp DL1 is abnormal, a detecting signal at a current detection circuit (a) is judged as abnormal by a control circuit (b), and a single signal for a time that the discharge lamp DL1 is left off, is outputted to a drive circuit (c). The drive circuit (c) receives the signal from the control circuit (b), so that a switching element S4 is instantaneously turned off. Namely, for example, suppose the discharge lamp would be abnormal while being light, the switching element S4 is instantaneously turned off the discharge lamp DL1 is left off the switching element S4 is turned on a discharge lamp DL2 is started (the discharge lamp DL1 will not be restarted because of high internal pressure developed directly after the lamp is turned out).

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 FIG. 9 is a conventional circuit diagram of a discharge lamp lighting device of this type disclosed in Japanese Patent Laid-Open No. 4-218255. In FIG. 9, a high pressure discharge lamp DL containing a plurality of discharge lamps (light emitting tubes) DL ₁ and DL ₂ whose lighting is controlled by the polarity of a starting pulse voltage, a ballast L ₁ and a power switch in the high pressure discharge lamp DL. An AC power supply V ₁ supplied via S ₁ , a pulse generation circuit P for selectively outputting a positive or negative starting pulse voltage superimposed on the voltage of the AC power supply V ₁ , and the power switch S ₁ And a control circuit T for selectively controlling the polarity of the starting pulse voltage output from the pulse generation circuit P when it is turned on.

The purpose of the discharge lamp lighting device shown in FIG. 9 is to start a plurality of arc tubes, that is, the discharge lamps DL ₁ and DL _{2 at} a rate of half each, and to start the discharge lamps DL ₁ and DL ₂ on _one side. Is to prevent it from being biased. Here, in FIG. 9, it is assumed that the discharge lamp DL ₁ becomes abnormal. Abnormality is a mode in which the lamp current continues to increase abnormally due to slow leak, half-wave, etc., and the heat generation of the ballast L ₁ becomes large, and if it continues for a long time, the winding of the ballast L ₁ generates heat. As a result, deterioration is promoted, and finally layer short-circuiting → disconnection, which makes it impossible to reuse the ballast L ₁ .

FIG. 10 can be considered as a means for solving the above problems. The same elements as those in FIG. 9 are designated by the same reference numerals and the description thereof will be omitted. In FIG. 10, d is an abnormal current detection circuit for detecting an abnormal current of the discharge lamp DL ₁ , and e
Is an abnormal current detection circuit for detecting an abnormal current of the discharge lamp DL ₂ . f is a drive circuit that drives the switching element S ₂ , and g is a drive circuit that drives the switching element S ₃ .

When the discharge lamp DL ₁ is abnormal, the abnormal current detection circuit d detects the abnormality, the switching element S ₂ is turned off via the drive circuit f, and the pulse is regenerated by the control circuit T. Then, the discharge lamp DL ₂ is started.

[0006]

In such a conventional example, the switching elements S ₂ and S ₃ for disconnecting the abnormal discharge lamp at the time of abnormality and the drive circuit f thereof are provided for the number of discharge lamps.
g is required, and when accommodating a plurality of discharge lamps in the outer tube, it is also necessary to take measures against heat generation of the switching elements S ₂ and S ₃ and their drive circuits f and g.
There was a problem that the lamp became extremely large and the cost increased.

Further, when both the discharge lamps DL ₁ and DL ₂ become abnormal, both lamps repeatedly blink and the ballast L
There is a problem in that heat generation of ₁ and burnout occur, and the ballast L ₁ cannot be reused. The present invention has been provided in view of the above points, and an abnormal discharge lamp is turned off and other discharge lamps are turned on, and the configuration is easy, and the size and cost are reduced. A lamp lighting device is provided.

[0008]

DISCLOSURE OF THE INVENTION The present invention relates to a discharge lamp lighting device for selectively lighting a plurality of discharge lamps by means of a starting pulse voltage generating means. Control means for detecting the occurrence of the abnormal discharge lamp by the output of the detecting means, and closing the switching element provided in series with the lighting main circuit to regenerate the starting pulse voltage. Is provided.

Further, according to a second aspect of the present invention, the discharge lamp is extinguished at a predetermined number or time by detecting the number of extinguishment times or time of the discharge lamp in the energized state and resetting by the power source. Later, the switching element is closed. Further, in the third aspect, the detection means for detecting the abnormality due to the slow leak of the discharge lamp is provided.

Further, in the present invention, the detecting means for detecting an abnormality due to the half-wave discharge of the discharge lamp is provided. According to a fifth aspect of the present invention, there is provided detection means for detecting the number of times or the time of extinguishing due to the rise in the tube voltage of the discharge lamp. Also,
In the sixth aspect, the switching element is provided in series with the discharge lamp main circuit.

Further, in claim 7, the switching element is connected to both electrodes of the discharge lamp.

[0012]

According to the present invention, the abnormal discharge lamp can be turned off and the other discharge lamps can be turned on, and the construction thereof is easy, and the size and cost can be reduced. Further, when all of the plurality of discharge lamps become abnormal, the safety of the lighting device can be ensured by cutting off the power supply.

Further, in the present invention, the number of times of extinction of the discharge lamp in the energized state or time is detected, and the extinction number detecting means for resetting by the power supply is provided, and the discharge lamp extinguishes at a predetermined number of times or time. After that, by closing the switching element, even if the discharge lamp becomes abnormal such as going out, the abnormal discharge lamp can be turned off by the switching element and other discharge lamps can be turned on. The configuration is easy, and the size and cost can be reduced.

Further, according to the third aspect of the present invention, since the detecting means for detecting the abnormality due to the slow leak of the discharge lamp is provided, even if the discharge lamp becomes abnormal due to the slow leak, the abnormal discharge lamp is detected by the switching element. The discharge lamp can be turned off and the other discharge lamps can be turned on, the configuration is easy, and the size and cost can be reduced. In addition, claim 4
In the above, since the detecting means for detecting the abnormality due to the half-wave discharge of the discharge lamp is provided, even if the discharge lamp has an abnormality due to the half-wave discharge, the abnormal discharge lamp is turned off by the switching element and other discharge is performed. The electric light can be turned on, its configuration is easy, and the size and cost can be reduced.

According to the present invention, the detection means for detecting the number of times or the time of extinguishing due to the rise of the tube voltage of the discharge lamp is provided, so that even if the discharge lamp becomes abnormal such as extinguishing due to the rise of the tube voltage, switching is performed. The abnormal discharge lamp can be turned off by the element and the other discharge lamps can be turned on, and the configuration thereof is easy, downsizing and cost reduction can be achieved.

Further, in the present invention, since the switching element is provided in series with the discharge lamp main circuit, the power supply is shut off by the switching element when all of the plurality of discharge lamps become abnormal. The safety of the lighting device can be ensured. Further, according to claim 7, the switching element is connected to both electrodes of the discharge lamp, so that the switching can be performed even in the case of a half-bridge or full-bridge type inverter lighting device or when the discharge lamp becomes abnormal. The abnormal discharge lamp can be turned off by the element and the other discharge lamps can be turned on, and the configuration thereof is easy, downsizing and cost reduction can be achieved.

[0017]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows a block diagram of this embodiment. Conventional Figure 9
The same elements as those in FIG. a is a current detection circuit inserted in the main circuit, and S ₄ is a switching element. Further, b is a control circuit which receives a signal from the current detection circuit a, and c is the switching element S ₄
Is a drive circuit for driving the.

Here, when the discharge lamp DL ₁ is abnormal, the control circuit b determines that the detection signal from the current detection circuit a is abnormal, and outputs a single-shot signal for the time when the discharge lamp DL ₁ goes out to the drive circuit c. . The drive circuit c receives the signal from the control circuit b,
The switching element S ₄ is momentarily turned off. That is, for example, if the discharge lamp DL ₁ becomes abnormal during lighting, the switching element S ₄ is momentarily turned off → the discharge lamp DL ₁ is turned off → the switching element S _{4 is} turned on → the discharge lamp DL ₂ is started (the discharge lamp DL ₁ Is immediately after turning off, so the internal pressure is high and it will not restart).

FIG. 2 shows a specific circuit example of FIG. The current detection circuit a is composed of a current transformer CT, a diode bridge DB and the like, and the counter circuit e is a counter I.
It is composed of C ₄ . The control circuit b has a comparator O
P ₁ , a timer IC ₂ , a timer IC _3, etc., and the drive circuit c is composed of a relay Ry. The switching element S ₄ is formed by the contact of the relay Ry.

Current detection circuit a, control circuit b, drive circuit c
The basic operation of is similar to FIG. The counter circuit e is
Electric light DL₁, DL₂Counter IC_FourIn cow
AC power supply V₁Counsed at least twice when the power is on
Then, the output signal changes from L level to H level. Mosquito
The output signal from the unter circuit e is a timer IC₃Output signal of
OR gate OR₂Is input to the counter IC
_FourOutput signal of H level, relay Ry
Turns on and the switching element S_FourTurn off the discharge lamp
DL₁, DL ₂Shut off the power supply circuit when both become abnormal.
I refuse. The above counter IC_FourPower reset
It is.

The counter circuit e includes discharge lamps DL ₁ and DL ₂
It is also effective when the lamp disappears repeatedly due to a rise in tube voltage at the end of its life. As described above, the faulty means when the discharge lamps DL ₁ and DL ₂ are abnormal has been described as a configuration in which the switching element S ₄ turns off the main circuit at least once. Any method may be used, such as connecting a sufficient impedance to the circuit in the lamp.

The discharge lamp is not limited to the case where a plurality of arc tubes are housed in the same outer tube, but a plurality of discharge lamps may be used. (Second Embodiment) FIG. 3 shows a second embodiment. The present embodiment is an example of a configuration in which the abnormal discharge lamp of the chopper type DC lighting system is turned off and the lighting of other discharge lamps is switched.

Switching element S ₄ , inductance L
₁ , a diode D _{1 and the} like form a chopper circuit, a is a detection circuit, d is a control circuit, h is an oscillation control circuit, and c is a drive circuit for driving the switching element S ₄ . In FIG. 3, when the discharge lamp is abnormal, the detection signal from the detection circuit a is judged to be abnormal by the control circuit d, and a single-shot signal for the time when the discharge lamp goes out is output. The drive circuit c receives the signal from the oscillation control circuit h and momentarily stops the oscillation of the switching element S ₄ .

In other words, if, for example, the discharge lamp DL ₁ becomes abnormal during lighting, the switching element S ₄ stops oscillating for a moment, the discharge lamp DL ₁ goes out, and the switching element S ₄ turns off.
Oscillation start of ₄ → discharge lamp DL ₂ is started (discharge lamp DL ₁ is not restarted). FIG. 4 shows a specific circuit diagram of FIG.
The detection circuit a is composed of a resistor Ra ₁ . The oscillation control circuit h is an oscillation IC for a switching regulator.
.IC ₁ , capacitor C that determines the fundamental oscillation frequency
b _1, is composed of a resistor Rb _1, the control circuit d includes a comparator OP _1, the OR gate G _1, the timer IC _2, I
It is composed of C ₃ , a transistor Q _{1 and the} like. Further, the drive circuit c is composed of a pulse transformer PT _{1 and the} like. Incidentally, Vcc is a control power supply.

First, the basic operation is as follows.
Receiving a voltage across the resistor Ra ₁ of the detection circuit a at the input IN of the oscillation IC _1, changing the H level / L level ratio of the signal at the output terminal OUT of the oscillation IC · IC ₁ by its magnitude.
The OUT signal of the oscillation IC · IC _1, drives the switching element S ₄ via a pulse transformer PT _1.

The operation when the discharge lamp DL ₁ is started → normally lighted → abnormal will be described below with reference to FIG. First, at time t ₁ , the AC power supply V ₁ is turned on, and at time t ₂ , FIG.
The discharge lamp DL ₁ is started as shown in (a). here,
The reference voltage V _REF of the comparator OP ₁ of the control circuit d shown in FIG. 4 is set between the normal voltage and the abnormal voltage as shown in FIG. 5B.

Output of comparator OP ₁ (voltage at point A)
Is as shown in FIG. After the trigger terminal voltage of the timer IC ₂ changes from the H level to the L level, as shown in FIG. 5D, the resistor Rd ₁ and the capacitor Cd ₁
The output becomes H level for the time determined by (voltage at point B).
The voltage at the C point of the output of the OR gate G ₁ is the same as the voltage at the A point and the B point.
It is as shown in FIG. 5 (e) when compared with the voltage at the point.

The timer IC ₃ receives the voltage signal at the point C, and after the point C changes from the H level to the L level, the resistor R 3
The output becomes H level for a time determined by d ₂ and the capacitor Cd ₂ (see FIG. 5F). When point D becomes H level,
Transistor Q ₁ turns on, oscillating IC · OU of IC ₁
The T signal maintains the L level, and the oscillation of the switching element S ₄ stops (see times t _{6 to} t _{7 in} FIG. 5G).

Then, when re-oscillating at time t ₇ , the discharge lamp DL ₂ is started. Here, the timer IC ₂ has a resistor R
In order to determine whether the discharge lamp starts when the detected voltage by a ₁ exceeds the threshold voltage or when there is an abnormality, it is necessary to determine at least the discharge lamp starting process time has elapsed after the threshold voltage has been exceeded. belongs to. In other words, more than the set time,
If the detection voltage across the resistor Ra ₁ exceeds the threshold voltage,
It is determined that the discharge lamp is abnormal.

The timer IC ₃ sets at least the time during which the discharge lamp goes out. (Embodiment 6) FIG. 6 shows Embodiment 3 in which discharge lamps DL ₁ and D _{1 are used} .
This is the case of a discharge lamp that requires the application of a high-voltage pulse voltage to start L ₂ .

A high voltage pulse voltage is applied to both ends of the discharge lamps DL ₁ and DL ₂ by the igniter IG, the pulse transformer PT and the capacitor C ₁ to start the discharge lamps. (Example 4) Example 4 is shown in FIG. In this embodiment, the pulse transformer P is provided for each of the discharge lamps DL ₁ and DL _2.
T _1, PT _2, the provided igniter IG _1, IG _2, thereby it is also possible to turn any of the discharge lamp DL _1, DL _2.

(Embodiment 5) In the above lighting device, the chopper type DC lighting is explained, but as shown in FIG. 8, it is also possible to use a polarity reversal type with switching elements Q _{1 to} Q ₄ , a so-called half bridge, full type. A bridge type inverter may be used. Also, a rectangular wave lighting type may be used.

In each of the above embodiments, the abnormality of the discharge lamp is detected by the voltage or current, but it may be detected by the discharge lamp voltage or the light. Further, the number of discharge lamps may be two or more. Furthermore, the discharge lamps are not limited to the same type, but different types,
Different watts, any combination will do.

[0034]

According to the present invention, in a discharge lamp lighting device for selectively switching and lighting a plurality of discharge lamps by means of a starting pulse voltage generating means, an abnormality of the discharge lamp is detected after lighting the discharge lamp. And a control means for regenerating the starting pulse voltage by closing the switching element provided in series with the lighting main circuit while making the abnormal discharge lamp a point by the output of the detection means. Therefore, the abnormal discharge lamp can be turned off and the other discharge lamps can be turned on, the configuration is easy, and the size and cost can be reduced. In addition, when all of the plurality of discharge lamps become abnormal, the safety of the lighting device can be ensured by cutting off the power supply.

According to the second aspect of the present invention, the number of extinguishing times or time of the discharge lamp in the energized state is detected, and the extinguishing number detecting means for resetting by the power supply is provided, and the discharge lamp extinguishes at a predetermined number of times or time. After that, by closing the switching element, even if the discharge lamp becomes abnormal such as going out, the abnormal discharge lamp can be turned off by the switching element and other discharge lamps can be turned on. The configuration is easy, and the size and cost can be reduced.

Further, according to the third aspect of the present invention, since the detecting means for detecting the abnormality due to the slow leak of the discharge lamp is provided, even when the discharge lamp becomes abnormal due to the slow leak, the abnormal discharge lamp is detected by the switching element. The discharge lamp can be turned off and the other discharge lamps can be turned on, the configuration is easy, and the size and cost can be reduced. In addition, claim 4
In the above, since the detecting means for detecting the abnormality due to the half-wave discharge of the discharge lamp is provided, even if the discharge lamp has an abnormality due to the half-wave discharge, the abnormal discharge lamp is turned off by the switching element and other discharge is performed. The electric light can be turned on, its configuration is easy, and the size and cost can be reduced.

According to the present invention, by providing the detection means for detecting the number of times or the time of extinguishing due to the rise of the tube voltage of the discharge lamp, even if the discharge lamp becomes abnormal such as extinguishing due to the rise of the tube voltage, switching is performed. The abnormal discharge lamp can be turned off by the element and the other discharge lamps can be turned on, and the configuration thereof is easy, downsizing and cost reduction can be achieved.

Further, in the present invention, since the switching element is provided in series with the discharge lamp main circuit, the power supply is shut off by the switching element when all of the plurality of discharge lamps become abnormal. The safety of the lighting device can be ensured. Further, according to claim 7, the switching element is connected to both electrodes of the discharge lamp, so that the switching can be performed even in the case of a half-bridge or full-bridge type inverter lighting device or when the discharge lamp becomes abnormal. The abnormal discharge lamp can be turned off by the element and the other discharge lamps can be turned on, and the configuration thereof is easy, downsizing and cost reduction can be achieved.

[Brief description of drawings]

FIG. 1 is a block diagram of a lighting device according to an embodiment of the present invention.

FIG. 2 is a specific circuit diagram of FIG. 1 above.

FIG. 3 is a block diagram of a second embodiment of the above.

4 is a specific circuit diagram of FIG. 3 above.

5 is a timing chart showing the operation of FIG. 4 above.

FIG. 6 is a block diagram of Embodiment 3 of the above.

FIG. 7 is a block diagram of Embodiment 4 of the above.

FIG. 8 is a block diagram of a fifth embodiment of the above.

FIG. 9 is a block diagram of a conventional lighting device.

FIG. 10 is a block diagram of another conventional lighting device.

[Explanation of symbols]

a current detection circuit b control circuit c drive circuit S ₄ switching element P pulse generation circuit DL ₁ discharge lamp DL ₂ discharge lamp

Claims (7)

[Claims] 1. A discharge lamp lighting device which selectively lights a plurality of discharge lamps by means of a starting pulse voltage generating means, comprising detection means for detecting an abnormality of the discharge lamp after lighting the discharge lamp. The abnormal discharge lamp is made defective by the output of the detection means, and a control means for closing the switching element provided in series in the lighting main circuit to regenerate the starting pulse voltage is provided. Discharge lamp lighting device. 2. A switching element is closed after the discharge lamp is extinguished at a predetermined number of times or time by detecting the number of extinguishing times or time of the discharge lamp in an energized state and reset by a power source. The discharge lamp lighting device according to claim 1, wherein the discharge lamp lighting device is formed. 3. The discharge lamp lighting device according to claim 1, further comprising detection means for detecting an abnormality caused by a slow leak of the discharge lamp. 4. The discharge lamp lighting device according to claim 1, further comprising detection means for detecting an abnormality due to half-wave discharge of the discharge lamp. 5. The discharge lamp lighting device according to claim 2, further comprising detection means for detecting the number of times the discharge lamp is extinguished due to a rise in the tube voltage or the time. 6. The discharge lamp lighting device according to claim 1, wherein the switching element is provided in series with the discharge lamp main circuit. 7. The discharge lamp lighting device according to claim 2, wherein a switching element is connected to both electrodes of the discharge lamp.