JPH08273857A - Lighting device for discharge lamp, discharge lamp lighting device and lighting system - Google Patents

Abstract

PURPOSE: To avoid an inconvenience such as cold start caused by existence of a striation preventing circuit and loss in the whole light lighting. CONSTITUTION: Operation of striation preventing circuits 18, 19 is prohibited with operation regulating means 20, 21 until the completion of the starting operation of discharge lamps 14, 15 is confirmed with a starting operation completion confirming means 25. In the start of the discharge lamps 14, 15, a DC bias caused by the striation preventing circuits 18, 19 is not superimposed on the secondary voltage, and cold start is avoided.

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, a discharge lamp lighting device and a lighting device.

[0002]

2. Description of the Related Art When a low-pressure mercury vapor discharge lamp containing an inert gas having a large atomic weight such as argon or krypton is lit by alternating current at low temperature or under dimming lighting (especially, deep dimming lighting) setting, the tube wall It is known that a striation phenomenon occurs in which a striped pattern appears. Although the mechanism of occurrence of this striation phenomenon has not been clarified yet, sometimes it occurs continuously during the lighting period, which causes an unpleasant sensation such as flicker.

As a measure for preventing the flicker of brightness due to such a striation phenomenon, it is effective to make the lamp current asymmetrical by positive and negative by applying a DC bias to the lamp current. The provision of a striation prevention circuit by means of
For example, it is disclosed in JP-A-57-118396.

FIG. 4 is a schematic circuit diagram showing a conventional discharge lamp lighting device having a striation prevention circuit. In the figure, a DC power supply 1 includes a half-bridge type inverter circuit 4 including a pair of switching elements 2 and 3,
LC with resonant inductor L ₁ and resonant capacitor C ₁
The discharge lamp 6 is connected through the resonance circuit 5 and the DC cut capacitor C ₂ . A striation prevention circuit 7 including a diode D ₁ and a resistor R ₁ is connected in parallel to the discharge lamp 6.

As a result, when the output of the inverter circuit 4 is in the forward direction with respect to the diode D ₁ , a lamp current flows through the discharge lamp 6 through the resistor R _1, and when it is in the reverse direction with respect to the diode D ₁ . The lamp current directly flows through the discharge lamp 6 without passing through the resistor R ₁ . As a result, the lamp current flowing through the discharge lamp 6 has a DC biased shape, and is in a positive / negative asymmetric state. The asymmetry ratio (positive / negative ratio) in this case is designed to be an optimal value, for example, 1.1 or more. Although the striation phenomenon occurs in the discharge lamp 6 due to the proper asymmetry of the lamp current due to the DC bias, the stripes move at a high speed due to the DC bias, and therefore the striation phenomenon cannot be visually recognized. Be done. Thereby, the flickering of brightness can be substantially prevented.

[0006]

By the way, when considering the starting of this kind of discharge lamp 6, the filament electrode is preheated and then the desired secondary voltage is applied between the filament electrodes to start the lighting. The soft start method is adopted.

FIG. 5 is a waveform diagram showing a lamp current waveform and a secondary voltage waveform (envelope waveform) according to the conventional soft start method. In this case, due to the action of the striation prevention circuit 7, the DC component is superimposed on the secondary voltage waveform before lighting even during the preheating operation, so that the effective value of the preheating voltage increases. As a result, a cold start may occur in which the discharge lamp 6 is turned on by the preheating voltage during the preheating of the filament electrode. Cold start of the discharge lamp 6 shortens the lamp life, which is not preferable.

On the other hand, in recent years, many inverter circuits 4 have a dimming function in order to improve the illumination effect. In this case, the inverter circuit 4 controls the oscillation frequency by the pair of switching elements 2 and 3 according to the dimming level set by the dimming level setting means,
The discharge lamp 6 is turned on with the brightness according to the dimming level. Here, a striation phenomenon occurs at the deep dimming level, but the action of the striation prevention circuit 7 substantially prevents the flicker of brightness. However, at the time of 100% dimming, that is, when all lights are turned on, although the striation phenomenon does not occur, there is a current component that is shunted to the striation prevention circuit 7, which causes a loss.

Therefore, the present invention uses a discharge lamp lighting device, a discharge lamp lighting device, and this discharge lamp lighting device, which can avoid inconveniences such as cold start due to the existence of a striation prevention circuit and loss at the time of all-light lighting. The purpose of the present invention is to provide an illuminating device.

[0010]

According to a first aspect of the present invention, there is provided an apparatus for lighting a discharge lamp, which comprises an inverter circuit for lighting the discharge lamp by an alternating current; A striation prevention circuit that activates the discharge lamp; a start operation end confirmation unit that confirms the end of the discharge lamp start operation; and an operation restriction unit that operates the striation prevention circuit after the end of the discharge lamp start operation is confirmed; Is equipped with.

A discharge lamp lighting device according to a second aspect of the present invention comprises a dimming level setting means for setting a dimming level; an operating state is controlled according to the set dimming level, and the discharge lamp is lit by alternating current. An inverter circuit that causes a lamp current for the discharge lamp to be DC biased to make the lamp current asymmetric between positive and negative; and a striation prevention circuit only when the dimming level is set by the dimming level setting means. And an operation restricting means for operating.

A discharge lamp lighting device according to a third aspect of the present invention comprises a dimming level setting means for setting a dimming level; an operation state is controlled in accordance with the set dimming level, and the discharge lamp is lit by alternating current. An inverter circuit for controlling; a striation prevention circuit for direct-biasing the lamp current for the discharge lamp to make this lamp current asymmetrical in positive and negative; a starting operation end confirming means for confirming the end of the starting operation of the discharge lamp; The operation control means operates the striation prevention circuit only when the dimming level is set by the setting means and the end of the starting operation of the discharge lamp is confirmed.

According to a fourth aspect of the invention, there is provided the discharge lamp lighting device according to the first or third aspect, in which the starting operation end confirmation means comprises a lighting detection means for detecting lighting of the discharge lamp.

According to a fifth aspect of the present invention, in the discharge lamp lighting device according to the first or third aspect, the starting operation end confirmation means is a preheating timer for managing the preheating time for the discharge lamp.

In each of the above inventions, the striation prevention circuit may be any circuit capable of DC biasing the lamp current to make the lamp current asymmetrical in positive and negative, for example, a series circuit of a diode and an impedance element or a parallel circuit. It can be configured by a circuit or the like. In addition, such a striation prevention circuit allows the discharge lamp to be connected in parallel or in series. As the operation regulation means, any means can be used as long as it can switch between a state in which the striation prevention circuit is involved and a state in which it is not involved in the lamp current, and the striation prevention circuit is connected in parallel to the discharge lamp. If the striation prevention circuit is connected in series to the discharge lamp, for example, the switches that can disconnect the striation prevention circuit are short-circuited. It can be configured by a short circuit, etc.

The discharge lamp lighting device according to the invention of claim 6 is:
The discharge lamp lighting device according to any one of claims 1 to 5; and a discharge lamp that is energized by the discharge lamp lighting device to be AC-lit.

An illumination device according to a seventh aspect of the present invention includes the discharge lamp lighting device according to the sixth aspect; and a fixture main body on which the discharge lamp lighting device is mounted.

[0018]

According to the first aspect of the invention, the operation of the striation prevention circuit is prohibited by the operation restricting means until the start operation end confirming means confirms the end of the starting operation of the discharge lamp. At start-up, the DC bias generated by the striation prevention circuit is not superimposed on the secondary voltage and the start-up does not start at the preheat voltage, so the discharge lamp does not cold start. When the starting operation is completed, the striation prevention circuit operates to substantially prevent the flickering of brightness due to the striation phenomenon.

According to the second aspect of the present invention, the striation prevention circuit prohibits the operation of the striation prevention circuit when the dimming level is not set by the dimming level setting means, and the striation phenomenon is prevented. Does not occur. No loss occurs due to the striation prevention circuit when lighting all lights. On the other hand, in the case of the dimming lighting in which the dimming level is set, the striation prevention circuit operates to substantially prevent the flickering of the brightness due to the striation phenomenon.

In the case of the third aspect of the invention, all-light lighting is performed until the completion of the starting operation of the discharge lamp is confirmed by the starting operation end confirming means, and the dimming level is not set by the dimming level setting means. In this case, the operation of the striation prevention circuit is prohibited by the operation restricting means, so that the cold start and the loss due to the striation prevention circuit at the time of lighting all lights are prevented. on the other hand,
The striation prevention circuit operates and the striation phenomenon occurs only when the completion of the starting operation of the discharge lamp is confirmed by the starting operation end confirming means and the dimming level is set by the dimming level setting means. Flickering of brightness due to is substantially prevented.

In the invention according to claim 4, when the lighting detecting means as the starting operation end confirming means detects the starting lighting of the discharge lamp, the striation prevention circuit is operated, so that the cold start due to the existence of the striation prevention circuit is performed. Completely prevented.

According to the fifth aspect of the invention, the striation prevention circuit is operated when the preheating timer times out and preheating is completed as the starting operation end confirming means. Therefore, the cold start due to the existence of the striation prevention circuit is almost eliminated. Completely prevented.

According to the invention of claim 6, claim 1
Since the discharge lamp lighting device according to any one of 1 to 5 is used, the discharge lamp is lit without any inconvenience such as cold start of the discharge lamp due to the presence of the striation prevention circuit and loss at the time of full light lighting. .

According to the invention of claim 7, claim 6 is provided.
Since the discharge lamp lighting device described above is used, the striation prevention circuit operates when necessary to perform lighting with reduced brightness flicker.

[0025]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a discharge lamp lighting device and a discharge lamp lighting device according to the present invention will be described with reference to FIGS. FIG.
Is a schematic circuit diagram showing a discharge lamp lighting device, and FIG. 2 is a waveform diagram showing a lamp current waveform and a secondary voltage waveform by a soft start method. The discharge lamp lighting device of the present embodiment is applied to two lamps, and the inverter circuit 1 is used for the DC power supply 11.
2, the LC resonance circuit 13, the current limiting inductor L ₂ and the DC cut capacitors C ₃ and C ₄ , and the two discharge lamps 14,
15 are connected in parallel. As the inverter circuit 12, for example, a half-bridge type high frequency inverter circuit including a pair of switching elements 16 and 17 is used. In addition, as the inverter circuit 12, for example, a drive control circuit (not shown) controls the oscillation frequencies of these switching elements 16 and 17 according to the dimming level to dimming the discharge lamps 14 and 15. A known dimming function is used. L
The C resonance circuit 13 is composed of a series circuit of a resonance inductor L ₅ and a resonance capacitor C ₅ .

Further, striation prevention circuits 18 and 19 are provided between the filament electrodes of the discharge lamps 14 and 15, respectively.
Are connected in parallel. As the striation prevention circuits 18 and 19, for example, a diode D
A series circuit of ₂ , D ₃ and resistors R ₂ , R ₃ is used. These striation prevention circuits 18 and 19 are provided with operation restricting means 20 and 21, respectively. As the operation restricting means 20 and 21, for example, the switch 2 in series with the striation prevention circuits 18 and 19 is used.
2, 23 are used.

On the other hand, a dimming level setting means 24 for setting the dimming level at the time of dimming lighting is provided. As the dimming level setting means 24, for example, a variable resistor that is arbitrarily operated by the user is used. The dimming level set by the dimming level setting means 24 is given to the drive control circuit for the inverter circuit 12. Further, the discharge lamps 14 and 15 are soft-started so as to start and light after a preheating operation, but a start operation end confirmation means 25 for confirming the end of the start operation of the discharge lamps 14 and 15 is provided. . The starting operation end confirmation means 25 may be a lighting detection means for detecting the actual lighting of the discharge lamps 14 and 15, but here, for example, a preheat timer 26 for managing the preheating time for the discharge lamps 14 and 15 is used. It is used.

An AND gate 27 is provided which controls the opening and closing of the switches 22 and 23 by using the output of the dimming level setting means 24 and the output of the starting operation end confirmation means 25 (preheat timer 26) as inputs. These switches 22 and 23 are opened and closed so that they are closed only when an output is output from the AND gate 27. That is, the switch 2 is operated only when the dimming level is set by the dimming level setting means 24 and the preheating timer 26 is up.
2 and 23 are closed and the dimming level is not set by the dimming level setting means 24 in the case of full light lighting, or the preheat timer 26.
If the time is not up, switches 22 and 2
Control to open 3.

The operation of such a discharge lamp lighting device will be described. First, when starting the discharge lamps 14 and 15,
The preheating timer 26 operates to perform the preheating operation in which the operation of the inverter circuit 12 is suppressed, and the preheating voltage as shown in FIG. 2B is applied to the filament electrodes of the discharge lamps 14 and 15. When the preheating time managed by the preheating timer 26 elapses, a high secondary voltage is applied between the filament electrodes of the discharge lamps 14 and 15, and the discharge lamps 14 and 15 are discharged.
Lights up when started. In this way, the soft start of the discharge lamps 14 and 15 is performed.

In such a soft start, the AND gate 27 does not output and the switches 22 and 23 are kept open until the preheat timer 26 times out. As a result, the striation prevention circuits 18 and 19 are separated from the discharge lamps 14 and 15 and do not operate. Therefore, at the time of starting, the lamp current is not DC biased by the striation prevention circuits 18 and 19, and the secondary voltage becomes positive and negative symmetrical as shown in FIG. 2B. Therefore, the effective value of the preheating voltage does not increase more than necessary, and the cold start in which the discharge lamps 14 and 15 are turned on during the preheating is prevented. As a result, the inconvenience of shortening the life of the discharge lamps 14 and 15 is avoided. Further, the lighting detection means does not detect the actual lighting of the discharge lamps 14 and 15,
The striation prevention circuits 18 and 19 are controlled so as not to operate by the time control by the preheat timer 26, but normally, if the preheat time by the preheat timer 26 has elapsed, the discharge lamps 14 and 15 are started and lit. It does not cause a cold start, so there is no problem.

When the preheat timer 26 times out, the AND gate 27 is provided on condition that the dimming level is set and the dimming level is set by the dimming level setting means 24.
Closes the switches 22 and 23 and allows the striation prevention circuits 18 and 19 to operate. As a result, as is well known, the striation prevention circuits 18 and 19 operate so as to apply a direct current bias to the lamp current, and the discharge lamps 14 and 15 are turned on in a state where the flicker of brightness due to the striation phenomenon is not visually recognized.

On the other hand, even if the preheat timer 26 expires, if the dimming level is not set by the dimming level setting means 24 and all lights are turned on, the switches 22 and 23 are turned on.
Is still open and striation prevention circuit 1
8 and 19 are in a separated state and do not operate. Therefore, the discharge lamps 14 and 15 can be lit without loss due to the striation prevention circuits 18 and 19 during all-light lighting in which the striation phenomenon does not occur.

As described above, according to this embodiment, the striation prevention circuits 18 and 19 can effectively function only when necessary.

An embodiment of the lighting device of the present invention will be described with reference to FIG. FIG. 3 is an external perspective view showing the lighting device. In the figure, reference numeral 28 denotes a lighting device, in which the discharge lamps 14 and 15 are detachably mounted and have a dimming function to turn on the discharge lamps 14 and 15 as shown in FIG. A discharge lamp lighting device 29 is installed.

[0035]

According to the first aspect of the present invention, the operation of the striation prevention circuit is prohibited until the end of the starting operation of the discharge lamp is confirmed. Cold start due to the bias being superimposed on the secondary voltage can be prevented.

According to the second aspect of the present invention, the operation of the striation prevention circuit is prohibited in the case of all-light lighting in which no striation phenomenon occurs, so that the loss due to the striation prevention circuit during all-light lighting is prevented. it can.

In the case of the third aspect of the invention, the operation of the striation prevention circuit is prohibited until the completion of the starting operation of the discharge lamp is confirmed and when all lights are turned on, so a cold start is performed. It is possible to prevent the loss due to the striation prevention circuit when all lights are turned on.

According to the fourth aspect of the present invention, the striation prevention circuit is operated when the lighting detection means detects the start lighting of the discharge lamp as the start operation end confirmation means. Therefore, the striation prevention circuit exists. Cold start due to can be completely prevented.

According to the fifth aspect of the present invention, the striation prevention circuit is operated when the preheating timer times out and preheating is completed as the start operation end confirmation means. Cold start can be almost completely prevented.

According to the sixth aspect of the present invention, since the discharge lamp lighting device according to any one of the first to fifth aspects is used, the presence of the striation prevention circuit causes the discharge lamp to cold start. The discharge lamp can be lit while avoiding the inconvenience that a loss occurs when all the lights are lit, and the life of the discharge lamp can be extended.

According to the invention described in claim 7, since the discharge lamp lighting device according to claim 6 is used, the striation prevention circuit is operated only at the minimum necessary time, and the flicker of brightness is reduced. Lighting can be done.

[Brief description of drawings]

FIG. 1 is a schematic circuit diagram showing an embodiment of a discharge lamp lighting device of the present invention.

FIG. 2 is a waveform diagram showing a lamp current waveform and a secondary voltage waveform.

FIG. 3 is an external perspective view showing an embodiment of a lighting device of the present invention.

FIG. 4 is a schematic circuit diagram showing a conventional discharge lamp lighting device.

FIG. 5 is a waveform diagram showing a lamp current waveform and a secondary voltage waveform.

[Explanation of symbols]

 12 Inverter Circuit 14, 15 Discharge Lamp 18, 19 Striation Prevention Circuit 20, 21 Operation Restricting Means 24 Dimming Level Setting Means 25 Starting Operation Completion Confirming Means 26 Preheating Timer 28 Instrument Main Body 29 Discharge Lamp Lighting Device

Claims (7)

[Claims] 1. An inverter circuit for alternating-currently lighting a discharge lamp; a striation prevention circuit for direct-biasing a lamp current for the discharge lamp to make the lamp current asymmetrical between positive and negative; confirming the end of the starting operation of the discharge lamp A discharge lamp lighting device comprising: a start operation end confirmation means; and an operation restriction means for operating a striation prevention circuit after the end of the discharge lamp start operation is confirmed. 2. A dimming level setting means for setting a dimming level; an inverter circuit for controlling the operating state according to the set dimming level to turn on the discharge lamp by alternating current; and a direct current for the lamp current to the discharge lamp. A striation prevention circuit that biases this lamp current to make it negative and positive.
A lighting device for a discharge lamp, comprising: an operation regulating unit that operates the striation prevention circuit only when the dimming level setting unit sets the dimming level. 3. A dimming level setting means for setting a dimming level; an inverter circuit for controlling the operating state according to the set dimming level to turn on the discharge lamp by alternating current; and a direct current for the lamp current to the discharge lamp. A striation prevention circuit that biases this lamp current to make it negative and positive.
A start operation end confirmation means for confirming the end of the start operation of the discharge lamp; and a striation prevention circuit only when the dimming level is set by the dimming level setting means and the end of the start operation of the discharge lamp is confirmed. A lighting device for a discharge lamp, comprising: an operation restricting unit that operates. 4. The discharge lamp lighting device according to claim 1 or 3, wherein the starting operation end confirmation means comprises lighting detection means for detecting lighting of the discharge lamp. 5. The discharge lamp lighting device according to claim 1, wherein the starting operation end confirming means comprises a preheating timer for managing a preheating time for the discharge lamp. 6. A discharge lamp lighting device according to any one of claims 1 to 5, and a discharge lamp which is energized by the discharge lamp lighting device and is AC-lit. Discharge lamp lighting device. 7. A lighting device comprising: the discharge lamp lighting device according to claim 6; and a fixture main body on which the discharge lamp lighting device is mounted.