JP2002117998A - Discharge lamp lighting device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a discharge lamp lighting device capable of reliably preventing the start of a discharge lamp in a dimmed state and being easily manufactured at a low cost. SOLUTION: This discharge lamp lighting device is provided with a dimming switching means 33 switching the discharge lamp 21 to dimmed lighting or undimmed lighting. A temperature sensing element 35 changing its electric quantities such as a resistance value, a reactance value, a voltage value, and a current value according to temperature is provided near the heating portion of the discharge lamp lighting device, and the dimming switching means 33 is prevented from being switched to dimmed lighting when the temperature sensing element 35 gets its electric quantities for the prescribed temperature or below.

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 which switches a discharge lamp between dimmable lighting and non-dimming lighting.

[0002]

2. Description of the Related Art For example, a conventional discharge lamp lighting device for dimming a high pressure discharge lamp is shown in FIG. 12 or FIG. In FIG. 12 or FIG.
Is a high-pressure discharge lamp, 2 is a main choke, 3 is an auxiliary choke (dimming choke), 5 is a capacitor for improving power factor, 6 is a discharge resistor, and is connected in parallel to the capacitor 5 for improving power factor. . The main choke 2 and the auxiliary choke 3 constitute a dimming type ballast 7.
And an AC current is supplied to the discharge lamp 1 via the LED, so that the discharge lamp 1 is lit or non-dimmed.

[0003] Reference numeral 11 denotes a dimming switching relay coil.
The relay coil 11 has a normally closed relay contact 12. And in the conventional discharge lamp lighting device of FIG.
The main choke 2 and the dimming choke 3 of the dimming type ballast 7 are arranged in series with each other.
The relay contacts 12 of the relay coil 11 are connected in parallel. Therefore, when a predetermined exciting current is supplied from the dimming power supply to the relay coil 11 by a switch operation or the like, the relay contact 12 is opened, and the discharge lamp is transmitted from the main power supply 9 via the main choke 2 and the dimming choke 3. Current is supplied to the discharge lamp 1 so that the current flowing through the discharge lamp 1 is reduced, and the discharge lamp 1 is dimmed. When the excitation current from the dimming power supply to the relay coil 11 is stopped or reduced to a predetermined level or less by a switch operation or the like, the relay contact 12 is closed, and the current is supplied from the main power supply 9 to the discharge lamp 1 via the main choke 2 only. Is supplied, and the discharge lamp 1 is non-dimmedly lit.

Further, in the conventional discharge lamp lighting device shown in FIG. 13, the auxiliary choke 3 of the dimming type ballast 7 is connected in parallel to the main choke 2 via the relay contact 12 of the relay coil 11, When a predetermined exciting current flows from the dimming power supply to the relay coil 11 by an operation or the like, the relay contact 12 is opened, and the discharge lamp 1 is supplied from the main power supply 9 to the discharge lamp 1 via only the main choke 2 of the dimming type ballast 7. A current is supplied, and the current flowing through the discharge lamp 1 is reduced, so that the discharge lamp 1 is dimmed. When the exciting current to the relay coil 11 is stopped or reduced to a predetermined level or less by a switch operation or the like, the relay contact 12 is closed, and the main power supply 9 passes through the main choke 2 and the auxiliary choke 3 of the dimming type ballast 7. An electric current is supplied to the discharge lamp 1 so that the discharge lamp 1 is not lit.

[0005]

However, in the conventional discharge lamp lighting device shown in FIG. 12 or FIG. 13, there is a possibility that the discharge lamp 1 is started in the dimming state, and the discharge lamp 1 in the state where the discharge lamp current is small. The starting caused a decrease in the temperature of the electrodes of the discharge lamp 1, which led to a short life of the discharge lamp 1 and poor starting. Therefore, FIG.
As shown in FIG. 4 or FIG. 15, a current detection coil 14 and a timer 15 are provided, and after a certain period of time has passed since the current detection coil 14 detected the discharge lamp current, the timer 15
The timer contact 16 is closed so that a predetermined exciting current can be passed from the dimming power supply to the relay coil 11 when a certain period has elapsed since the start of the discharge lamp 1. In some lamps, starting of the discharge lamp 1 in a state where the discharge lamp current is small is prevented, thereby shortening the life of the discharge lamp 1 and preventing starting failure.

However, the conventional discharge lamp lighting device shown in FIG. 14 or FIG. 15 requires a timer or the like, and has a problem that the production is troublesome and the production cost is high. SUMMARY OF THE INVENTION In view of the above problems, the present invention can reliably prevent starting of a discharge lamp due to a dimming state and can be manufactured at low cost and easily.

[0007]

The technical means of the present invention for solving this technical problem is a discharge lamp provided with dimming switching means 33 for switching the discharge lamp 21 between dimming lighting and non-dimming lighting. In the lighting device, a temperature-sensitive element 35 whose resistance, reactance value, voltage value, current value, or the like changes depending on temperature is provided in the vicinity of the heat generating portion of the discharge lamp lighting device. The point is that the switch to the dimming lighting of the dimming switching means 33 is disabled when the amount of electricity corresponding to the temperature or less is reached.

Another technical means of the present invention resides in that the temperature sensing element 35 is constituted by a thermistor whose resistance value changes with temperature. Further, another technical means of the present invention includes a relay coil 31 for switching dimming,
By passing a predetermined exciting current through the relay coil 31,
Dimming and lighting the discharge lamp 21 and the relay coil 31
By setting the exciting current to the discharge lamp 21
In the discharge lamp lighting device in which the non-dimming lighting is performed, a temperature-sensitive element 35 whose resistance value decreases with temperature is provided in the vicinity of the heat generating portion of the discharge lamp lighting device.
The point is that a temperature sensing element 35 is connected in series to the relay coil 31 so that a predetermined exciting current does not flow through the relay coil 31 when the resistance is high.

Another technical means of the present invention is a power supply 2
9 and a discharge lamp 21, a dimming choke 23 is interposed between the dimming choke 23 and the relay coil 31.
Are provided in parallel, and a predetermined exciting current is supplied to the relay coil 31 to open the relay contact 32 to dim the discharge lamp 21 and to reduce the exciting current to the relay coil 31 by a predetermined amount. By:
The point is that the relay contact 32 is closed and the discharge lamp 21 is configured to perform non-dimming lighting.

Another technical means of the present invention is a power supply 2
9 and the discharge lamp 21, a dimming choke 23 is interposed, the dimming choke 23 is short-circuited, and the discharge lamp 21 is not dimmed and lit, and a current is supplied from the power supply 29 through the dimming choke 23. In the discharge lamp lighting device in which the discharge lamp 21 is supplied so as to perform dimming lighting, a temperature sensing element 35 whose resistance value increases with temperature is provided near a heat generating portion of the discharge lamp lighting device. The point is that the temperature sensing element 35 is connected in parallel to the dimming choke 23 so that the discharge lamp 21 does not dimmingly light when the resistance 35 is low.

Another technical means of the present invention is that the temperature sensing element 35 is disposed near the discharge lamp 21. Another technical means of the present invention is that the temperature sensing element 35 is arranged near the main choke 22 of the dimming type ballast 27. Another technical means of the present invention is to detect a tube voltage of the discharge lamp 21 in a discharge lamp lighting device provided with dimming switching means 33 for switching the discharge lamp 21 between dimming lighting and non-dimming lighting. Tube voltage detection circuit 4
9 when the tube voltage detected by the tube voltage detection circuit 49 is equal to or lower than a predetermined voltage.
In that the switching to the dimmable lighting is disabled.

[0012]

Embodiments of the present invention will be described below with reference to the drawings. In FIG. 1, reference numeral 21 denotes a high-pressure discharge lamp, which is constituted by, for example, an HID lamp. Here, the HID lamp is a high intensity.
It is an abbreviation for high-pressure mercury lamp, metal halide lamp, and high-pressure sodium lamp. HID lamps are also called high-intensity discharge lamps, and are characterized by their small size, high output, high efficiency, and long life.

22 is a main choke, 23 is a dimming choke (auxiliary choke), 25 is a power factor improving capacitor,
A discharge resistor 6 is connected in parallel to a power factor improving capacitor 25. Main Choke 22 and Dimming Choke 2
3, a dimming-type ballast 27 is formed, and an alternating current is supplied from the main power supply 29 to the discharge lamp 21 via the dimming-type ballast 27, and the discharge lamp 21 is dimmed or turned on. (Full lighting without dimming). 30
Is a power switch.

Reference numeral 31 denotes a dimming switching relay coil.
The relay coil 31 has a normally closed relay contact 32. The main choke 2 of the dimming type ballast 27
2 and the dimming choke 23 are arranged in series with each other,
A relay contact 32 of a relay coil 31 is connected in parallel to the dimming choke 23. Reference numeral 34 denotes a light control switch. Accordingly, the dimming switching means 33 for switching the discharge lamp 21 between dimming lighting and non-dimming lighting includes a dimming power supply (not shown), a relay coil 31 having a relay contact 32,
It is composed of a dimming switch 34 for connecting the relay coil 31 and a dimming power supply. When a predetermined exciting current flows from the dimming power supply to the relay coil 31 by operating the dimming switch 34 or the like, the relay contact 3
2 is opened, a current is supplied from the main power supply 29 to the discharge lamp 21 via the main choke 22 and the dimming choke 23, so that the current flowing through the discharge lamp 21 decreases,
Is dimmed. Further, when the exciting current from the power supply for light control to the relay coil 31 is stopped or reduced to a predetermined value or less by operating the switch for light control 34 or the like,
When the relay contact 32 is closed, the main choke 2
A current is supplied to the discharge lamp 21 via only the discharge lamp 2, so that the discharge lamp 1 is not lit.

Reference numeral 35 denotes a temperature-sensitive element (heat-sensitive element) whose resistance value decreases with temperature (the resistance decreases when the temperature exceeds a predetermined temperature).
The discharge lamp lighting device is constituted by a thermistor or the like, and is disposed near the main choke 22 which is a heat generating portion of the discharge lamp lighting device.
The temperature sensing element 35 is connected in series to the relay coil 31. When the temperature sensing element 35 is lower than a predetermined temperature,
The resistance value becomes high, making it impossible to switch the dimming switching means 33 to dimming lighting. That is, the main choke 2 before a certain period elapses from the start of the discharge lamp 21.
Before the temperature sensing element 35 becomes high temperature due to the heat generation of 2, the temperature sensing element 35 has a high resistance, and even if the dimming switch 34 is turned on, a predetermined exciting current does not flow through the relay coil 31. It has become. After the discharge lamp 21 is started, when the temperature of the temperature sensitive element 35 becomes high due to heat generation of the discharge lamp 21, the resistance of the temperature sensitive element 35 becomes low, and when the dimming switch 34 is turned on, a predetermined voltage is applied to the relay coil 31. Is allowed to flow.

According to the above embodiment, the power switch 3
When the discharge lamp 21 is started by, for example, turning ON the discharge lamp 21, an alternating current is supplied from the main power supply 29 to the discharge lamp 21 via the main choke 22 of the dimmable ballast 27, and the discharge lamp 21 is out of adjustment. Lights up (full lighting without dimming). At this time, if a certain period of time has not elapsed since the discharge lamp 21 was started, the temperature of the thermosensitive element 35 becomes high due to the heat generated by the main choke 22, and the thermosensitive element 35 is in a high resistance state. From
Even if the dimming switch 34 is turned on, the relay coil 3
No predetermined exciting current flows through the switch 1. Therefore, relay contact 3
2, the dimming choke 23 is short-circuited at the relay contact 32 and the main choke 2
2, a current is supplied to the discharge lamp 21 so that the discharge lamp 21 maintains non-dimming lighting.

When a certain period of time has elapsed after the discharge lamp 21 is started, the heat generated by the main choke 22 causes the temperature-sensitive element 3 to move.
5 becomes high temperature and the temperature sensing element 35 becomes low resistance,
When the dimming switch 34 is turned on, a predetermined exciting current flows from the dimming power supply to the relay coil 31 and the relay contact 32 is opened, so that the main power supply 29 passes through the main choke 22 and the dimming choke 23. As a result, a current is supplied to the discharge lamp 21, so that the current flowing through the discharge lamp 21 is reduced, and the discharge lamp 21 is dimmed. In addition, when the dimming operation is performed, the discharge lamp 21 is turned on.
Disappears, the temperature of the main choke 22 decreases,
Until the temperature sensing element 35 reaches a return temperature (a temperature at which the temperature sensing element 35 becomes so low that dimming lighting cannot be performed), the power supply for dimming is still applied to the relay coil 11, Due to the characteristics of the electric lamp 21, the temperature of the discharge lamp 21 decreases, and it takes about 10 minutes until the discharge lamp 21 can be turned on again. Is not started.

Therefore, it is possible to reliably prevent the discharge lamp 21 from starting in the dimming state, and to eliminate the possibility that the discharge lamp 21 starts in a state where the discharge lamp current is small.
It is possible to prevent the temperature of the first electrode from lowering and prevent the discharge lamp 21 from having a short life and poor starting. In addition, a timer or the like is not required, the number of parts is reduced, the manufacturing is easy, and the manufacturing cost is reduced. FIG. 2 shows another embodiment, in which a temperature sensing element 35 is arranged in the vicinity of the discharge lamp 21 which is another heat generating part of the discharge lamp lighting device, instead of the vicinity of the main choke 22. Other points are the same as those of the above-described embodiment.

FIG. 3 shows another embodiment in which the relay contact 32 of the relay coil 31 is connected in parallel to the dimming choke 23 and the temperature sensing element 35 is connected to the temperature control element 35 in the same manner as in the previous embodiment. The temperature-sensitive element 35 is a main choke 22 of the dimming-type ballast 27 which is a heat-generating portion of the discharge lamp lighting device. , And the temperature sensing element 35 is connected in parallel to the dimming choke 23. Therefore, in this case, before a certain period of time has elapsed since the start of the discharge lamp 21 and before the temperature of the temperature sensing element 35 becomes high due to the heat generated by the main choke 22, the temperature sensing element 35 has a low resistance. Dimming choke 2 with element 35
3 is short-circuited, a current is supplied from the main power supply 29 to the discharge lamp 21 without passing through the dimming choke 23, and the discharge lamp 2
1 is configured to perform non-dimming lighting, and when the temperature-sensitive element 35 is lower than a predetermined temperature, switching of the dimming switching unit 33 to dimming lighting is disabled. And the discharge lamp 21
After the start of the operation, when the temperature of the temperature sensing element 35 becomes high due to heat generation,
The temperature-sensitive element 35 has a high resistance, and a current is supplied to the discharge lamp 21 via the dimming choke 23 to allow the dimming lighting of the discharge lamp 21.

FIG. 4 shows another embodiment, in which a temperature sensing element 3 is provided.
5 is arranged in the vicinity of the discharge lamp 21 which is another heating part of the discharge lamp lighting device, instead of the vicinity of the main choke 22. The other points are the same as those in the embodiment of FIG. FIG. 5 shows another embodiment, wherein the auxiliary choke 23 of the dimming type ballast 27 is connected in parallel to the main choke 22 via the relay contact 32 of the relay coil 31. Accordingly, when a predetermined exciting current is supplied from the dimming power supply to the relay coil 31 by a switch operation of the dimming switch 34 or the like, the relay contact 32 is opened, and the main choke of the dimming type ballast 27 is transmitted from the main power supply 29. Discharge lamp 2 only via 22
1, the current flowing through the discharge lamp 21 is reduced, and the discharge lamp 21 is dimmed and lit. When the exciting current to the relay coil 31 is stopped or reduced to a predetermined value or less by a switch operation of the dimming switch 34 or the like, the relay contact 32 is closed, and the main choke 22 and the main choke 22 of the dimming type ballast 27 are Auxiliary choke 23
A current is supplied to the discharge lamp 21 via the LED, so that the discharge lamp 21 is turned off.

The temperature sensing element 35 is composed of a thermistor or the like whose resistance value decreases with temperature (the resistance decreases when the temperature exceeds a predetermined temperature), and is located near the main choke 22 which is a heat generating portion of the discharge lamp lighting device. Are located. Also,
The temperature sensing element 35 is connected in series to the relay coil 31, and when the temperature sensing element 35 is lower than a predetermined temperature, the resistance value becomes high resistance, and the light adjustment switching unit 33 performs dimming lighting. Switching is disabled. That is, the discharge lamp 21
Before a certain period has elapsed since the start of the operation, and before the temperature sensing element 35 becomes high temperature due to the heat generated by the main choke 22, the temperature sensing element 35 has a high resistance. Also, a predetermined exciting current does not flow through the relay coil 31. And after starting the discharge lamp 21,
When the temperature of the temperature sensing element 35 becomes high due to the heat generated by the discharge lamp 21, the resistance of the temperature sensing element 35 becomes low, and the light control switch 3
The on operation of 4 allows a predetermined exciting current to flow through the relay coil 31.

FIG. 6 shows another embodiment, in which a temperature-sensitive element 3 is provided.
5 is arranged in the vicinity of the discharge lamp 21 which is another heating part of the discharge lamp lighting device, instead of the vicinity of the main choke 22. Other points are the same as those in the embodiment of FIG. FIG. 7 shows another embodiment, in which the auxiliary choke 23 of the dimming type ballast 27 is connected to the relay contact 3 of the relay coil 31 as in the case of the embodiment of FIG. 5 or FIG.
2 is connected in parallel to the main choke 22. Accordingly, when a predetermined exciting current is supplied from the dimming power supply to the relay coil 31 by a switch operation of the dimming switch 34 or the like, the relay contact 32 is opened, and the main choke of the dimming type ballast 27 is transmitted from the main power supply 29. A current is supplied to the discharge lamp 21 via only the discharge lamp 22, and the current flowing through the discharge lamp 21 is reduced, whereby the discharge lamp 21 is dimmed and lit.
When the exciting current to the relay coil 31 is stopped or reduced to a predetermined value or less by a switch operation of the dimming switch 34 or the like, the relay contact 32 is closed, and the main choke 22 and the main choke 22 of the dimming type ballast 27 are A current is supplied to the discharge lamp 21 via the auxiliary choke 23, so that the discharge lamp 21 is not lit.

As in the case of the embodiment shown in FIG. 3 or FIG. 4, the temperature-sensitive element 35 is a negative-characteristic thermistor or the like whose resistance value increases with temperature (it becomes high when the temperature exceeds a predetermined temperature). The temperature sensing element 35 is a main choke 2 of the dimming type ballast 27 which is a heat generating portion of the discharge lamp lighting device.
2 are arranged in the vicinity. Further, the temperature sensing element 35 is connected in parallel to the relay contact 32 of the relay coil 31. Therefore, in this case, before a certain period of time has elapsed since the start of the discharge lamp 21 and before the temperature of the temperature sensing element 35 becomes high due to the heat generated by the main choke 22, the temperature sensing element 35 has a low resistance. The relay contact 32 is short-circuited by the element 35,
Even if the relay contact 32 is opened by turning on the dimming switch 34, current is supplied from the main power supply 29 to the discharge lamp 21 via the main choke 22 and the auxiliary choke 23, so that the discharge lamp 21 is not lit. And the temperature sensing element 35
When the temperature is equal to or lower than the predetermined temperature, switching of the dimming switching means 33 to dimming lighting is disabled. And discharge lamp 2
When the temperature sensing element 35 becomes high temperature due to heat generation after the start of the first step, the temperature sensing element 35 becomes high resistance, and the light control switch 3
When the relay contact 32 is opened by turning on the main power supply 4, the main power supply 2
A current is supplied to the discharge lamp 21 from only the main choke 22 via the main choke 22, thereby allowing the dimming lighting of the discharge lamp 21.

FIG. 8 shows another embodiment, wherein a dimming type ballast is used as a dimming type ballast 27. A primary coil 41, a secondary coil 42, a dimming choke (auxiliary choke) 23 and A capacitor 43 is connected to both ends of the primary coil 41, and both ends of a part of the primary coil 41 and a series circuit of the dimming choke 23 and the secondary coil 42,
The high pressure discharge lamp 21 is connected. The relay contact 32 of the relay coil 31 is connected in parallel to the dimming choke 23 of the dimming type ballast 27. Therefore, when a predetermined exciting current flows from the dimming power supply to the relay coil 31 by the switch operation of the dimming switch 34 or the like, the relay contact 32 is opened, and the primary coil 41 and the secondary coil 4
An electric current is supplied to the discharge lamp 21 through the dimming choke 23 and the dimming choke 23, so that the current flowing through the discharge lamp 21 is reduced, and the discharge lamp 21 is dimmed and lit. When the exciting current from the dimming power supply to the relay coil 31 is stopped or reduced to a predetermined level or less by operating the dimming switch 34 or the like, the relay contact 32 closes and the main power supply 29 is closed.
, A current is supplied to the discharge lamp 21 via the primary coil 41 and the secondary coil 42, so that the discharge lamp 1 is not lit.

The temperature sensing element 35 is constituted by a thermistor or the like whose resistance value decreases with temperature (the resistance decreases when the temperature exceeds a predetermined temperature), and the dimming type ballast 27 which is a heat generating portion of the discharge lamp lighting device. In the vicinity of the secondary coil 42. The temperature sensing element 35 is connected in series to the relay coil 31. When the temperature sensing element 35 is lower than a predetermined temperature, its resistance value becomes high, and the light adjustment switching unit 33 performs light adjustment. Switching to lighting is disabled. That is, before a certain period of time has elapsed from the start of the discharge lamp 21 and before the temperature sensing element 35 becomes high in temperature due to the heat generated by the secondary coil 42, the temperature sensing element 35 has a high resistance, and the light control switch Even when the switch 34 is turned on, a predetermined exciting current does not flow through the relay coil 31. And
After the discharge lamp 21 is started, when the temperature of the temperature sensing element 35 becomes high due to the heat generated by the discharge lamp 21, the resistance of the temperature sensing element 35 becomes low, and a predetermined excitation of the relay coil 31 is performed by turning on the dimming switch 34. The current is allowed to flow.

FIG. 9 shows another embodiment, in which the temperature sensing element 3 is used.
5 is arranged in the vicinity of the discharge lamp 21 which is another heating part of the discharge lamp lighting device, instead of the vicinity of the main choke 22. The other points are the same as in the embodiment of FIG. FIG. 10 shows another embodiment. As in the case of the embodiment shown in FIG. 8 or FIG.
Is a leakage transformer type, has a primary coil 41, a secondary coil 42, a dimming choke (auxiliary choke) 23, and a capacitor 43 is connected to both ends of the primary coil 41. The high-pressure discharge lamp 21 is connected to both ends of a part of the series circuit of the dimming choke 23 and the secondary coil 42.

A relay contact 32 of a relay coil 31 is connected in parallel to the dimming choke 23 of the dimming type ballast 27. Therefore, when a predetermined exciting current is passed from the dimming power supply to the relay coil 31 by a switch operation of the dimming switch 34 or the like, the relay contact 32 is opened, and the primary coil 41 and the secondary coil 42 A current is supplied to the discharge lamp 21 via the dimming choke 23, and the current flowing through the discharge lamp 21 is reduced, so that the discharge lamp 21 is dimmed and lit. When the exciting current from the dimming power supply to the relay coil 31 is stopped or reduced to a predetermined level or less by operating the dimming switch 34 or the like, the relay contact 32 closes, and the primary coil 41
An electric current is supplied to the discharge lamp 21 through the secondary coil 42 and the secondary coil 42, so that the discharge lamp 1 is turned on and off.

As in the case of the embodiment shown in FIG. 7, the temperature-sensing element 35 is constituted by a negative-characteristic thermistor or the like whose resistance value increases with temperature (high resistance when the temperature exceeds a predetermined temperature). This temperature sensing element 35 is arranged near the secondary coil 42 of the dimming type ballast 27, which is a heat generating portion of the discharge lamp lighting device. The temperature sensing element 35 is connected in parallel to the dimming choke 23 and the relay contact 32 of the relay coil 31. Therefore, in this case, before a certain period of time has elapsed since the start of the discharge lamp 21 and before the temperature of the temperature sensing element 35 becomes high due to heat generation of the secondary coil 42, the temperature sensing element 3
5 has a low resistance, the dimming choke 23 is short-circuited by the temperature sensing element 35, and the relay contact 32 is opened by turning on the dimming switch 34. A current is supplied to the discharge lamp 21 via the secondary coil 42, and the discharge lamp 21 is turned off without light. When the temperature sensing element 35 is at or below a predetermined temperature, the light control of the light control switching means 33 is performed. Switching to light lighting is disabled. When the temperature of the temperature sensing element 35 becomes high due to heat generation after the discharge lamp 21 is started, the resistance of the temperature sensing element 35 becomes high, and the relay contact 3 is turned on by turning on the dimming switch 34.
When the lamp 2 is opened, a current is supplied from the main power supply 29 to the discharge lamp 21 via the primary coil 41, the secondary coil 42, and the dimming choke 23, thereby allowing the dimming lighting of the discharge lamp 21. ing.

FIG. 11 shows another embodiment, and FIG.
2, 3 and 4, the relay contact 32 of the relay coil 31 is connected to the dimming choke 23 in parallel. The discharge lamp 21 is provided with resistors 47 and 4.
8 are connected in parallel, and a resistor 4
A relay coil 53 having a normally open relay contact 52 is connected between a midpoint of the discharge lamp 21 and one end of the discharge lamp 21 via a triac 51, and the relay contact 52 of the relay coil 53 is dimmed. Relay coil 31 of switching means 33
Is connected in series, so that when the tube voltage detected by the tube voltage detection circuit 49 is equal to or lower than a predetermined voltage, the dimming switching unit 33 cannot switch to dimming lighting.

Therefore, in this case, the relay contact 52 is opened before the lamp voltage (the voltage between both ends) of the discharge lamp 21 becomes higher than a predetermined voltage before a predetermined period has elapsed since the start of the discharge lamp 21, and the relay contact 52 is opened. Even when the light switch 34 is turned on, a predetermined exciting current does not flow through the relay coil 31. Therefore, the relay contact 32 remains closed, the dimming choke 23 is short-circuited at the relay contact 32, and current is supplied from the main power supply 29 to the discharge lamp 21 via the main choke 22. Holds non-dimming lighting. When a predetermined period has elapsed after the discharge lamp 21 has been started, the tube voltage of the discharge lamp 21 becomes equal to or higher than a predetermined voltage. Therefore, a predetermined exciting current flows through the relay coil 53, and the relay contact 52 is closed. Accordingly, when the dimming switch 34 is turned on, a predetermined exciting current flows from the dimming power supply to the relay coil 31 and the relay contact 32 is opened.
An electric current is supplied to the discharge lamp 21 via the light control choke 23 and the dimming choke 23, so that the current flowing through the discharge lamp 21 is reduced, and the discharge lamp 21 is dimmed and lit.

In the above embodiment, the temperature sensing element 35
Is constituted by a thermistor or a negative temperature coefficient thermistor whose resistance value changes with temperature, and when the temperature-sensitive element 35 has a resistance value equal to or lower than a predetermined temperature, switching of the dimming switching means 33 to dimming lighting is disabled. But the temperature sensing element 35
Is not limited to the element whose resistance value changes with temperature, but may be a temperature-sensitive element whose electric quantity such as a reactance value, a voltage value, and a current value changes with temperature. For example, the temperature sensing element 35 is constituted by a temperature sensing reactance element, and the temperature sensing element 3
When the value of 5 becomes a re-actance value corresponding to a predetermined temperature or less, the switching of the dimming switching unit 33 to dimming lighting may be disabled.

In the above embodiment, the dimming switching means 33 causes a predetermined exciting current to flow from the dimming power supply to the relay coil 31 by opening the dimming switch 34 to open the relay contact 32. The dimming switching means 33 is not limited to such a configuration, but may be replaced with another configuration. For example, a dimming switch for manual operation may be provided in parallel with the dimming choke 23, and switching between dimming lighting and non-dimming lighting may be performed by operating the dimming switch.

In the above embodiment, the temperature sensing element 35
Are disposed in the vicinity of the main choke 22 or the like, which is the heat generating portion of the discharge lamp lighting device, or in the vicinity of the discharge lamp 21, but the position where the temperature sensing element 35 is disposed is not limited thereto. As long as it is in the vicinity of the heat generating portion, it may be arranged at another position. Further, in the above-described embodiment, a high-pressure discharge lamp such as an HID lamp is used as the discharge lamp 21, but the present invention uses a discharge lamp such as a fluorescent lamp other than the high-pressure discharge lamp as the discharge lamp 21. The present invention can be applied to an electric lighting device.

[0034]

According to the present invention, the starting of the discharge lamp 21 due to the dimming state can be reliably prevented, and the short life of the discharge lamp 21 and the starting failure can be prevented. In addition, a timer or the like is not required, and it can be manufactured at low cost and easily.

[Brief description of the drawings]

FIG. 1 is a circuit diagram showing an embodiment of the present invention.

FIG. 2 is a circuit diagram showing another embodiment.

FIG. 3 is a circuit diagram showing another embodiment.

FIG. 4 is a circuit diagram showing another embodiment.

FIG. 5 is a circuit diagram showing another embodiment.

FIG. 6 is a circuit diagram showing another embodiment.

FIG. 7 is a circuit diagram showing another embodiment.

FIG. 8 is a circuit diagram showing another embodiment.

FIG. 9 is a circuit diagram showing another embodiment.

FIG. 10 is a circuit diagram showing another embodiment.

FIG. 11 is a circuit diagram showing another embodiment.

FIG. 12 is a circuit diagram showing a conventional example.

FIG. 13 is a circuit diagram showing another conventional example.

FIG. 14 is a circuit diagram showing another conventional example.

FIG. 15 is a circuit diagram showing another conventional example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 21 High-pressure discharge lamp 22 Main choke 23 Dimming choke 27 Dimming type stabilizer 29 Main power supply 31 Relay coil 32 Relay contact 34 Dimming switching means 35 Temperature sensing element 49 Tube voltage detection circuit

Claims (8)

[Claims] 1. A discharge lamp lighting device provided with dimming switching means (33) for switching a discharge lamp (21) between dimmable lighting and non-dimming lighting. A temperature-sensitive element (35) in which an electric quantity such as a resistance value, a reactance value, a voltage value, and a current value changes according to a temperature;
A discharge lamp lighting device characterized in that the switch to the dimming lighting of the dimming switching means (33) is disabled when the amount of electricity becomes equal to or less than a predetermined temperature. 2. The discharge lamp lighting device according to claim 1, wherein the temperature-sensitive element is formed of a thermistor whose resistance changes with temperature. 3. A relay coil for switching dimming.
And a dimming operation of the discharge lamp (21) by flowing a predetermined exciting current through the relay coil (31).
In a discharge lamp lighting device in which the exciting current to the relay coil (31) is set to be equal to or less than a predetermined value, the discharge lamp (21) is caused to perform non-dimming lighting. A temperature-sensitive element (35) whose resistance value decreases is provided, and the temperature-sensitive element (3) is provided.
When 5) has a high resistance, the relay coil (3) is set so that a predetermined exciting current does not flow through the relay coil (31).
(1) A discharge lamp lighting device, wherein a temperature sensing element (35) is connected in series. 4. A dimming choke (23) is interposed between a power supply (29) and a discharge lamp (21), and the dimming choke (23) is connected to a relay contact (21) of the relay coil (31). 32) are provided in parallel, and when a predetermined exciting current is applied to the relay coil (31), the relay contact (32) is opened to dimming the discharge lamp (21), and the relay coil (31) 4. The discharge device according to claim 3, wherein the relay contact is closed and the discharge lamp is non-dimmed by setting the exciting current to the predetermined value or less. Lighting device. 5. A dimming choke (23) is interposed between a power supply (29) and a discharge lamp (21), and the dimming choke (23) is short-circuited to make the discharge lamp (21) non-dimming. In a discharge lamp lighting device, which is lit and supplies a current from a power supply (29) via a dimming choke (23) to dimmingly light a discharge lamp (21), a heat-generating portion of the discharge lamp lighting device A temperature-sensitive element (35) whose resistance value increases with temperature is provided near the temperature-sensitive element (3).
The temperature sensing element (35) is provided with a dimming choke (23) so that the discharge lamp (21) does not dim the lighting when 5) has a low resistance.
A lighting device for a discharge lamp, which is connected in parallel to the discharge lamp. 6. The discharge lamp (2), wherein the temperature sensing element (35) is
2. The device according to claim 1, wherein the device is arranged near (1).
6. The discharge lamp lighting device according to any one of claims 5 to 5. 7. The device according to claim 1, wherein the temperature-sensitive element is arranged near a main choke of a dimmable ballast. Discharge lamp lighting device. 8. A discharge lamp lighting device provided with dimming switching means (33) for switching a discharge lamp (21) between dimmable lighting and non-dimming lighting, wherein a tube voltage of the discharge lamp (21) is detected. Tube voltage detection circuit (4
9) is provided, and when the tube voltage detected by the tube voltage detection circuit (49) is equal to or lower than a predetermined voltage, the dimming switching means (33) cannot switch to dimming lighting. Discharge lamp lighting device.