JP2001118691A - Lighting device of high pressure discharge lamp - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable a discharge lamp to re-light instantaneously without shortening its own life by re-lighting. SOLUTION: A resistor 3 is connected serially to primary winding 2a between constant voltage power supply V1 and primary winding 2a, and capacitor C is connected in parallel to primary winding 2a between the resistor 3 and the primary winding 2a. Namely, an integrating circuit is constructed between the constant voltage power supply V1 and the primary winding 2a. A starting voltage hereby, increases in proportion as the duration of applied start-up voltage to the primary winding 2a increases. Accordingly, during the period of ordinary lighting, a lamp 7 lights while the start-up voltage is not so high, and at the instantaneous re-lighting, the lamp 7 re-lights while starting voltage is higher than that of ordinary lighting. Thus, the lamp 7 re-lights instantaneously so that high voltage which is necessary at instantaneous re-lighting may not be impressed to the lamp 7, and the lamp 7 and its ballast are enabled not to shorten their own life.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a high-pressure discharge lamp lighting device for general lighting such as a mercury lamp and a metal halide lamp.

[0002]

2. Description of the Related Art Conventionally, ballasts used as lighting devices for high-pressure discharge lamps such as mercury lamps and metal halide lamps have been known. FIG. 5 shows a simplified diagram of a conventional circuit configuration of the ballast 101. As shown in the figure, M is applied to both ends of the primary winding 102a of the transformer 102.
The OS switches Q3 and Q4 are connected, and the primary winding 102
A high voltage is applied to the middle point of a. On the other hand, a rectangular voltage by the lamp drive circuit unit 103 is applied to the secondary winding 102b of the transformer 102. By turning on and off the MOS switches Q3 and Q4 at a predetermined timing, the starting voltage applied to the primary winding 102a is reduced by the transformer 102.
At high pressure, and used as an ignition pulse. FIG. 6 shows the ignition pulse waveform at this time.

The ignition pulse generated at a predetermined timing as described above is added to a rectangular voltage by the lamp driving circuit unit 103, and a high voltage is applied to a discharge lamp (hereinafter, referred to as a lamp) 104. I have.

In this ballast 101, the lamp 10
The ignition pulse required to turn on No. 4 is different depending on the state of the lamp 104,
Immediately after stopping the lighting operation, since the pressure in the lamp 104 is high, the breakdown voltage (discharge start voltage) of the lamp 104 becomes higher than that during normal lighting.
Therefore, the cooling time of the lamp 1 is about 10 to 15 minutes.
04 is not turned on again. That is,
As shown in FIG. 7, the breakdown voltage of the discharge lamp 104 decreases with an increase in the cooling time, but when no cooling time is provided, the high voltage generated as the ignition pulse shown in FIG. Since the voltage becomes lower than the high voltage required at the time of relighting, the lamp 104 does not relight even if an ignition pulse is generated.

[0005] As described above, the high pressure discharge lamp is not suitable for the purpose of instantaneously relighting. For this reason, in general lighting employing a high-pressure discharge lamp, an incandescent lamp is also used as preliminary lighting depending on the location.

[0006]

As described above, it is necessary to further increase the ignition pulse voltage in order to perform instantaneous relighting (hot restart) of a high pressure discharge lamp lighting device for general lighting. It is said. In particular,
Lamp 104 during normal lighting (cold start)
While the voltage applied to the lamp is 3 to 5 kV, a high voltage exceeding 20 kV is required as the lamp applied voltage during instantaneous relighting. For example, 25-35k for a mercury lamp
For V and metal halide lamps, a high voltage of 20 kV or more is required.

[0007] However, if a method in which a high voltage is applied to such an extent that instantaneous relighting can be performed is always applied, there is a problem that not only the life of the lamp itself is shortened but also the life of the ballast itself is shortened.

SUMMARY OF THE INVENTION In view of the above, it is an object of the present invention to provide a high pressure discharge lamp lighting device that can instantaneously relight a lamp and does not cause a reduction in the life of the lamp or the device itself even after the relighting.

[0009]

In order to achieve the above object, according to the first aspect of the present invention, a primary winding (2a) to which a starting voltage is applied from a predetermined power supply (V1), and a primary winding. A transformer (2) having a secondary winding (2b) for increasing the voltage applied to the wire to a high voltage is provided, and a high voltage is applied to a discharge lamp (7) connected to the secondary winding. A high-pressure discharge lamp lighting device for lighting the discharge lamp,
A voltage adjusting means (R3, C) for increasing the starting time as the application time when the starting voltage is applied to the primary winding becomes longer between the secondary winding and the primary winding. Features.

As described above, if the starting voltage is increased as the application time of the starting voltage to the primary winding becomes longer, the discharge lamp is turned on when the starting voltage is not so large during normal lighting. In addition, at the time of instantaneous relighting, the discharge lamp can be relighted when the starting voltage becomes higher than at the time of normal lighting.

[0011] With this, it is possible to prevent the high voltage required at the time of instantaneous relighting from being always applied to the discharge lamp even during normal lighting, so that the discharge lamp can be instantaneously relighted and the discharge lamp or the high pressure discharge lamp can be used. It is possible to prevent the life of the device itself from being shortened.

For example, a resistor (R3) connected in series to the primary winding between a predetermined power supply (V1) and the primary winding, and a resistor and the primary side By providing an integration circuit having a capacitor (C) connected in parallel with the primary winding between the winding and the primary winding, the effect described in claim 1 can be obtained.

According to the third aspect of the present invention, the primary winding (2a) to which the starting voltage is applied and the secondary winding (2a) for increasing the voltage applied to the primary winding to a high voltage. 2b)
A discharge lamp (7) including a transformer (2) including a transformer and a case (11) for housing the transformer, and disposed outside the case.
A high-pressure discharge lamp lighting device for applying a high voltage boosted by the secondary winding to the discharge lamp and lighting the discharge lamp includes a temperature sensor (R4) for detecting the temperature of a predetermined portion of the case. Voltage adjusting means (10, R4, R5) for adjusting the voltage so that the starting voltage applied to the primary winding increases as the temperature detected by the sensor increases.

As described above, by providing the voltage adjusting means for adjusting the voltage so that the starting voltage applied to the primary winding becomes higher as the temperature of the predetermined portion of the case becomes higher, it is possible to perform the normal lighting or the instantaneous restart. The starting voltage is adjusted in accordance with the temperature that changes depending on whether the lamp is lit or not, and a relatively low starting voltage can be applied to the primary winding during normal lighting and a relatively high voltage during instantaneous relighting.

[0015] With this, it is possible to prevent the high voltage required at the time of instantaneous relighting from being always applied to the discharge lamp even during normal lighting, so that the discharge lamp can be instantaneously relighted and the discharge lamp or the high pressure discharge lamp can be used. It is possible to prevent the life of the device itself from being shortened.

For example, a thermistor can be used as the temperature sensor, and the voltage adjusting means changes the amount of current supplied to the primary winding based on a change in the resistance of the thermistor. Thus, the starting voltage applied to the primary winding can be adjusted.

More specifically, as a voltage adjusting means, a resistor (R) connected in series to the thermistor and dividing the voltage of the constant voltage source (V2) together with the thermistor is used.
5) and an operational amplifier (10) for generating a current corresponding to a potential difference between a voltage divided by a thermistor and a resistor and a predetermined reference voltage (E), and the current generated by the operational amplifier is wound on the primary side. What is necessary is just to make it flow in a line.

The reference numerals in parentheses of the above means indicate the correspondence with specific means described in the embodiments described later.

[0019]

(First Embodiment) FIG. 1 shows a circuit configuration of a ballast 1 to which a first embodiment of the present invention is applied. Hereinafter, the configuration of the ballast 1 in the present embodiment will be described with reference to FIG.

As shown in FIG. 1, the ballast 1 is provided with a transformer 2 composed of a primary winding 2a and a secondary winding 2b. Primary winding 2 of this transformer 2
One end of a is provided with a MOS switch Q1 via a resistor R1, and the other end is provided with a MOS switch Q2 via a resistor R2. These MOS switches Q1,
Q2 is controlled by the switch drive circuit 3, and is turned on and off alternately at a predetermined timing.

On the other hand, a lamp drive circuit section 4 for generating a rectangular voltage is connected to one end of the secondary winding 2b of the transformer 2. The other end of the secondary winding 2b is connected to a terminal 5, and a terminal 6 connected to the terminal 5 and the ground.
And a lamp 7 is connected between them.

Further, a constant voltage source V is connected through a resistor R3 to a middle point (center of the winding) of the primary winding 2a of the transformer 2.
1 is connected. Further, the resistor R3 and the primary winding 2a
And the ground, that is, the primary winding 2a, the resistors R1, R2, and the MOS switches Q1, Q2 as viewed from the resistor R3.
2 is provided with a capacitor C so as to be connected in parallel. An integrating circuit is formed by the resistor R3 and the capacitor C so that the voltage applied from the constant voltage source V1 can be boosted according to the time constant.

Next, the operation of the ballast 1 having the above configuration will be described. When a lamp switch (not shown) is turned on, a rectangular voltage by the lamp driving circuit unit 4 is applied to the lamp 7.
And the switch control circuit 3 controls the ON / OFF of the MOS switches Q1 and Q2. And MO
When the S switches Q1 and Q2 are turned on and off, the primary winding 2
a of the primary winding 2a around the midpoint of the
Current path passing through S switch Q1 side and MOS switch Q
A current alternately flows in a current path passing through the two sides. As a result, the starting voltage is applied to the primary winding 2a and is converted to a high voltage by the secondary winding 2b to be a high voltage. , Applied to the lamp 7.

At this time, as described above, the constant voltage source V1
Is applied to the primary winding 2a via the integration circuit, so that charge is accumulated in the capacitor C as the application time elapses, and the primary winding 2a And the amount of ignition pulse generated in the secondary winding 2b increases. That is,
The integrating circuit serves as a voltage adjusting means, and adjusts the voltage so that the starting voltage increases as the application time of the starting voltage to the primary winding 2a increases, so that the ignition pulse increases.

FIG. 2 shows a waveform of an ignition pulse generated in the secondary winding 2b at this time. Assuming that the potential at the connection point between the resistor R3 and the capacitor C is Vig, as shown in FIG. 2, the ignition pulse also increases in accordance with the integral waveform of the potential Vig, and a high voltage (for example, 20 kV or more) required for instantaneous relighting is obtained. Voltage).

Therefore, during normal lighting (cold start) when the lamp 7 is not at a high temperature, the ignition pulse rises to a voltage required as a breakdown voltage of the lamp 7 in a short time, and the lamp 7 is lit. Then, during an instantaneous relighting (hot restart) in which the lamp 7 is at a high temperature, the lamp 7 is turned on when the ignition pulse is boosted to a voltage required as a breakdown voltage of the lamp 7. For this reason, instantaneous relighting can be performed without providing a cooling time.

As described above, the constant voltage source V
By increasing the voltage of the lamp 1 with time, the ignition pulse can be increased with time, and the lamp 7 can be turned on at a relatively low applied voltage at the time of normal lighting, and the high applied voltage can be obtained only at the time of instantaneous relighting. The lamp 7 can be turned on by the voltage.

Thus, during normal lighting, it is possible to prevent the high voltage required at the time of instantaneous relighting from being applied to the lamp 7, so that it is possible to prevent the high voltage from being applied to the lamp 7 at all times. Life and Ballast 1
Life can be improved. In addition, at the time of instantaneous relighting, a higher voltage can be applied to the lamp 7 than at the time of normal lighting, so that the lamp 7 can be relighted quickly without providing a cooling period.

(Second Embodiment) FIG. 3 shows the configuration of a ballast 1 according to a second embodiment of the present invention. Since the ballast 1 in the present embodiment is almost the same as the first embodiment,
The same components as those in the first embodiment are denoted by the same reference numerals as those in FIG. 1, and only different portions will be described.

As shown in FIG. 3, the voltage of the constant voltage source V2 is changed to a temperature detecting resistor R4 and a resistor R5 as a temperature sensor.
The divided voltage and the reference voltage E are input to the non-inverting input terminal and the inverting input terminal of the operational amplifier 10, respectively, and a current corresponding to a potential difference between them is supplied to the primary side of the transformer 2. It is configured to flow through the winding 2a.

The temperature detecting resistor R4 is housed in a case 11 for housing various circuit parts constituting the ballast 1, and is in contact with a part of the case 11. A thermistor is used as the temperature detection resistor R4,
The resistance value is changed according to the temperature change of the case 11. In the present embodiment, a thermistor whose resistance increases as the temperature rises is used.

Next, the operation of the ballast 1 having the above configuration will be described. When a lamp switch (not shown) is turned on, a high voltage boosted by the transformer 2 is added to the rectangular voltage by the lamp drive circuit unit 4 and applied to the lamp 7 as in the ballast 1 shown in FIG.

At this time, as described above, the constant voltage source V2
The amount of current flowing from the operational amplifier 10 to the primary winding 2a is controlled in accordance with the potential difference between the voltage obtained by dividing the voltage due to the above and the reference voltage E, so that the primary side is changed by the resistance value of the temperature detection resistor R4. The amount of current flowing through the winding 2a changes. Specifically, as the temperature increases, the resistance value of the temperature detection resistor R4 increases, and the voltage value input to the non-inverting input terminal of the operational amplifier 10 increases. Is increased, and the amount of current flowing through the primary winding 2a is increased. That is, the temperature detection resistor R4,
A voltage adjusting means is constituted by the resistor R5 and the operational amplifier 10, and controls a starting current applied to the primary winding 2b by controlling an amount of current flowing through the primary winding 2a.

For this reason, the ignition pulse generated in the secondary winding 2b increases as the amount of current flowing through the primary winding 2a increases. FIG. 4 shows a waveform of an ignition pulse generated in the secondary winding 2b at this time.

As shown in this figure, when the temperature of the member 11 constituting the ballast 1 is low and low, the ignition pulse is also small because the potential difference is small. The magnitude of the ignition pulse in this case corresponds to the breakdown voltage of the lamp 7 during normal lighting, and the lamp 7 is lit during normal lighting based on the ignition pulse.

When the member 11 constituting the ballast 1 is at a higher temperature than at the time of normal lighting, for example, at an intermediate temperature which is relatively higher than that at the time of normal lighting, or at a high temperature which is even higher than at the time of medium temperature The potential difference increases, and the ignition pulse also increases according to the potential difference. The magnitude of the ignition pulse in this case corresponds to the breakdown voltage of the lamp 7 required at the time of relighting, and the lamp 7 is lit at the time of instantaneous relighting based on this ignition pulse. For this reason, instantaneous relighting can be performed without providing a cooling time.

As described above, the primary winding 2a depends on the temperature.
The amount of current flowing through the lamp 7 is changed so that the ignition pulse becomes higher as the temperature becomes higher, so that the lamp 7 is turned on at a relatively low applied voltage at the time of normal lighting, and the high applied voltage is obtained only at the time of instantaneous relighting. The lamp 7 can be turned on with a voltage. Thereby, the same effect as in the first embodiment can be obtained.

In this embodiment, the temperature detection resistor R4 is arranged in the case 11 for accommodating various circuit portions of the ballast 1. Lamp 7 according to the temperature of lamp 7
Since the internal pressure is determined, the temperature detecting resistor R
Although it is conceivable to arrange the high pressure discharge lamp 4 directly, there are various types of high pressure discharge lamp lighting devices, and the ballast 1 and the lamp 7 are not always arranged close to each other. For this reason, when the ballast 1 and the lamp 7 are arranged apart from each other, it is necessary to extend the wiring from the ballast 1 to the lamp 7 and arrange the temperature detection resistor R4. Such a defect can be eliminated by directly arranging R4.
When the lamp 7 is turned on, the temperature of the ballast 1 also rises, and the temperature rise of the ballast 1 is almost proportional to the temperature rise of the lamp 7. It is possible to control the ignition pulse as in the case where the temperature is directly detected.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating a circuit configuration of a ballast 1 according to a first embodiment of the present invention.

FIG. 2 is a diagram showing a relationship between an application time and an ignition pulse in the ballast 1 shown in FIG.

FIG. 3 is a diagram illustrating a circuit configuration of a ballast 1 according to a second embodiment of the present invention.

FIG. 4 is a diagram showing a relationship between a detected temperature of a temperature detection resistor and an ignition pulse in the ballast 1 shown in FIG. 3;

FIG. 5 is a diagram showing a circuit configuration of a conventional ballast.

6 is a diagram showing a relationship between an application time and an ignition pulse in the ballast shown in FIG. 5;

FIG. 7 is a diagram showing a relationship between a lamp cooling time and a discharge starting voltage (breakdown voltage).

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Ballast, 2 ... Transformer, 2a ... Primary side winding, 2b
... Secondary winding, 3 ... Switch control circuit, 4 ... Lamp drive circuit section, 5,6 ... Terminal, 7 ... Lamp, 11 ... Case, 1
0: operational amplifier, R1, R2, R3, R5: resistor, R4
... Temperature detection resistors, Q1 to Q4 ... MOS switches.

Continued on the front page (72) Inventor Hideki Hokimoto 1-1-1 Showa-cho, Kariya-shi, Aichi F-term in DENSO Corporation (Reference) 3K083 AA07 BA04 BA23 BC13 BC34 BC48 BD09 BD12 BE13 BE22 CA33

Claims (5)

[Claims] 1. A primary winding (2a) to which a starting voltage is applied from a predetermined power supply (V1), and a secondary winding (2b) for increasing a voltage applied to the primary winding to a high voltage. A high voltage discharge lamp lighting device for applying the high voltage to the discharge lamp (7) connected to the secondary winding and lighting the discharge lamp. Between the and the primary winding, the longer the application time of applying the starting voltage to the primary side winding,
A high pressure discharge lamp lighting device comprising a voltage adjusting means (R3, C) for increasing the starting time. 2. A primary winding (2a) to which a starting voltage is applied from a predetermined power supply (V1), and a secondary winding (2b) for increasing a voltage applied to the primary winding to a high voltage. A high voltage discharge lamp lighting device for applying the high voltage to the discharge lamp (7) connected to the secondary winding and lighting the discharge lamp. And a resistor (R3) connected in series with the primary winding between the primary winding and the primary winding, and a resistor (R3) connected between the resistor and the primary winding with respect to the primary winding. A high pressure discharge lamp lighting device comprising an integration circuit having a capacitor (C) connected in parallel. 3. A primary winding (2) to which a starting voltage is applied.
a) and a transformer (2) including a secondary winding (2b) for increasing a voltage applied to the primary winding to a high voltage.
And a case (11) accommodating the transformer, wherein a high voltage boosted by the secondary winding is applied to a discharge lamp disposed outside the case, and a high voltage for lighting the discharge lamp is provided. In the discharge lamp lighting device, a temperature sensor (R) for detecting a temperature of a predetermined portion of the case.
Voltage adjusting means (10, R4, R5) for adjusting the voltage so that the starting voltage applied to the primary winding increases as the temperature detected by the temperature sensor increases.
And a high pressure discharge lamp lighting device, comprising: 4. The primary winding according to claim 1, wherein the temperature sensor is a thermistor, and the voltage adjusting means changes an amount of current supplied to the primary winding based on a change in resistance of the thermistor. The high pressure discharge lamp lighting device according to claim 3, wherein a starting voltage applied to the line is adjusted. 5. The voltage adjusting means is connected in series to the thermistor, and a resistor (R5) for dividing a voltage of a constant voltage source (V2) together with the thermistor; and a voltage divided by the thermistor and the resistor. An operational amplifier (10) for generating a current corresponding to a potential difference from a predetermined reference voltage (E), wherein the current generated by the operational amplifier is caused to flow through the primary winding. The high pressure discharge lamp lighting device according to claim 4.