JP3439755B2 - Light bulb type electrodeless discharge lamp - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lighting device (a discharge lamp lighting device) for lighting a discharge lamp and a bulb-shaped electrodeless discharge lamp.

[0002]

2. Description of the Related Art In recent years, as a discharge lamp lighting device, an electronic lighting device (inverter) has come into widespread use from the viewpoint of improving the luminous efficiency and downsizing and weight saving of the device. Such a discharge lamp lighting device is disclosed in JP-A-10-162983 and JP-A-2000-353598. The conventional discharge lamp lighting device will be described below.

FIG. 6 shows the structure of a discharge lamp lighting device disclosed in Japanese Patent Laid-Open No. 2000-353598. The discharge lamp lighting device shown in FIG.
An inverter circuit 31, a control terminal drive circuit 23,
The resonance load circuit 30 includes the fluorescent lamp 8.

The DC power supply 22 includes an AC power supply 1, a noise prevention capacitor 2, a diode bridge 3 and a smoothing capacitor 4.
The configuration of the DC power supply 22 is a general configuration for converting the AC of the AC power supply 1 into DC and outputting the DC. The inverter circuit 31 has FETs 5 and 6, and the FETs 5 and 6 are switching elements with control terminals (gates). In the inverter circuit 31, the FET
By turning 5 and 6 on and off alternately, direct current is converted to alternating current. The FETs 5 and 6 are on / off controlled by the control terminal drive circuit 23, and the control terminal drive circuit 23 includes the secondary winding 10A of the transformer 10, which is a drive winding, the capacitor 14, and the second capacitor 17. Zener diodes 15 and 16, which are voltage clamp elements, and resistors 1 and 2.
3 and 19 and the second inductor 11.

The fluorescent lamp 8 which is a discharge lamp is a part of the resonant load circuit 30, and the resonant load circuit 30 includes the fluorescent lamp 8, the first capacitor 7, and the electrodes 8A and 8B of the fluorescent lamp 8. A condenser 9 for preheating and a first
And a primary winding 10B of a transformer 10 which is an inductor of

In the above structure, the DC power source 22
The DC output of FET5 is controlled by the control terminal drive circuit 23.
The 6 is alternately turned on and off to be converted into an alternating current, and the alternating current is applied to the resonance load circuit 30, whereby the fluorescent lamp 8 can be turned on by the alternating current.

Next, the operation of the discharge lamp lighting device having the configuration shown in FIG. 6 will be described.

When the AC power supply 1 is turned on, the pulsating current waveform, which is full-wave rectified by the rectifier circuit 3, is smoothed by the capacitor 4, and the both ends of the capacitor 4 substantially match the peak value of the AC power supply 1. DC voltage is generated.

The DC voltage generated across the capacitor 4 is applied to the series circuit of the FETs 5 and 6 which are the inverter circuit 31, and also to the series circuit of the resonance load circuit 30 and the resistor 19, thereby to form the capacitor 7 and the capacitor. 9 is charged.

At the same time, the DC voltage generated across the capacitor 4 is applied to the series circuit of the resistor 12, the inductor 11, the secondary winding 10A of the transformer 10, the capacitor 14, and the resistor 19 of the control terminal drive circuit 23, Then, the capacitor 14 is charged with electric charges with a predetermined time constant.
The maximum voltage that can be generated across the capacitor 14 is
The DC voltage generated across the capacitor 4 is applied to the resistors 12, 1
It is less than or equal to the voltage generated across the resistor 13 when the voltage is divided by 3 and 19.

At this time, when the voltage of the capacitor 14 charged with a predetermined time constant reaches the Zener voltage of the Zener diode 15, the charge of the capacitor 14 is supplied to the gate terminal of the FET 5 and the FET 5 is turned on. FE
When T5 is turned on, the electric charges stored in the capacitors 7 and 9 are transferred to the FET 5 and the primary winding 10B of the transformer 10.
Be discharged through. Here, an induced voltage is generated in the secondary winding 10A of the transformer 10 by the current flowing through the primary winding 10B of the transformer 10, and the inductor 11 and the capacitor 17 are formed by the induced voltage of the secondary winding 10A. Since the series resonant circuit oscillates at a resonance frequency determined by the inductor 11 and the capacitor 17, an oscillating voltage is generated across the capacitor 17.

The oscillating voltage keeps the FET 5 on for a predetermined period of time, and thereafter, a voltage in the reverse bias direction is generated between the gate and the source of the FET 5, so that the FET 5 is turned off. At the same time, a voltage in the forward bias direction is applied between the gate and the source of the FET 6, which means that FE
T6 is turned on. When the FET6 is turned on,
The DC voltage generated across the capacitor 4 is used as a power source, the capacitor 7, the fluorescent lamp 8, and the primary winding 10 of the transformer 10.
A current flows through B and FET6. This current charges the capacitors 7 and 9 with electric charges.

At this time, the current flowing through the primary winding 10B of the transformer 10 is in the opposite direction to that when the FET 5 is turned on, and the secondary winding 10A of the transformer 10 has an induced voltage of the opposite polarity to that of the former. It is generated and oscillates at a resonance frequency determined by the inductor 11 and the capacitor 17, and an oscillating voltage is generated across the capacitor 17. FET6 by the vibration voltage
Keeps the ON state for a predetermined period, and thereafter, the voltage in the reverse bias direction is generated between the gate and the source of the FET 6, so that the FET 6 is turned off. At the same time, a voltage in the forward bias direction is applied between the gate and source of the FET 5, and the FET 5 is turned on.

Thereafter, the FETs 5 and 6 are alternately turned on.
The off state is repeated, and alternating current is applied to the resonant load circuit 30. When AC is applied to the resonant load circuit 30, immediately after the AC power supply 1 is turned on, the capacitor 7, the electrode 8A, the capacitor 9, the electrode 8B, and the primary winding 10B of the transformer 10 are provided.
A current flows through the electrodes, and a preheating current is supplied to the electrodes 8A and 8B of the fluorescent lamp 8. Since the resonance load circuit 30 constitutes a series resonance circuit, a preheating current is supplied and at the same time, a high voltage is generated as a resonance voltage across the capacitor 9.

Here, the temperature of the electrodes is raised by the preheating current to the electrodes 8A and 8B, thermoelectrons are easily generated, and the high voltage across the capacitor 9 is applied across the fluorescent lamp 8. The fluorescent lamp 8 starts discharging. When the fluorescent lamp 8 starts discharging, the impedance of the fluorescent lamp 8 lowers, and most of the current flowing through the capacitor 7 flows through the fluorescent lamp 8 and stable discharge can be maintained.

[0016]

According to the above-mentioned conventional structure, the fluorescent lamp 8 can be turned on and operated without any particular problem. When a lighting experiment was conducted by changing to an electrodeless fluorescent lamp, it was found that in that case, it was not configured to reliably light. further,
It was also found that even in the case of the fluorescent lamp 8 having an electrode, the fluorescent lamp 8 has not reached a configuration that can be reliably turned on in any environment.

On the other hand, making a drastic change in the structure of the lighting device for lighting the fluorescent lamp 8 increases the cost of the product, and a new problem arises in the modified structure. It will be necessary to carefully consider whether or not this will occur.

The present invention has been made in view of the above points, and a main object thereof is to provide a discharge lamp lighting device capable of reliably lighting a fluorescent lamp with a simple structure.

[0019]

[0020]

[0021]

[0022]

[0023]

[0024]

[0025]

Self-ballasted electrodeless discharge lamp according to the present invention SUMMARY OF THE INVENTION comprises a electrodeless discharge lamp, the electrodeless discharge lamp in Mu bulb-type in which the lighting circuit and the mouthpiece for supplying power formed by integrally formed An electrode discharge lamp, wherein the lighting circuit is electrically connected to the base and outputs a direct current voltage to a direct current power supply circuit part, and a switching switch with a control terminal for converting an output from the direct current power supply circuit part into an alternating voltage. in element
An inverter circuit including an n-type FET and a p-type FET, a control terminal drive circuit for controlling on / off of the switching element with control terminal, and the electrodeless discharge lamp.
A resonance load circuit including a first inductor and a first capacitor, wherein the control terminal drive circuit includes a drive winding interconnected with the first inductor, and the drive winding. a voltage clamping element connected to at least one end of a series circuit of a resistor, said voltage Clan
Connected in parallel to the series circuit of the resistor and the resistor.
A second capacitor and a second inductor, and
The second inductor, the drive winding, and the second capacitor.
And a closed circuit formed by
The lamp element is an AC signal generated in the second capacitor.
Is an element that conducts when the signal is greater than or equal to a predetermined value,
By resonating the capacitor and the second inductor,
The switching element with a control terminal is controlled to be turned on and off, and
The resistor limits the current flowing through the voltage clamp element.
The second capacitor and the second inductor
To prevent the resonance frequency determined by
It

In a preferred embodiment, the electrodeless discharge lamp, the lighting circuit and the base are further covered,
An illumination cover having an opening in the emitting direction is provided.

[0027]

BEST MODE FOR CARRYING OUT THE INVENTION The inventor of the present application has clarified the mechanism that cannot be reliably turned on with the conventional configuration, and
With a simple configuration of adding an impedance element, a high voltage is surely generated at both ends of a capacitor connected to the fluorescent lamp, and the fluorescent lamp is successfully lit, thereby completing the present invention. Came to.

Here, the reason why the conventional structure cannot reliably turn on the light will be described. First, as a premise,
In the configuration shown in FIG. 6, the voltage generated at both ends of the primary winding 10B of the transformer 10 is largely different before and after the fluorescent lamp 8 starts discharging. Paying attention to this point, and continued a more detailed examination.

Since the electrodes 8A and 8B of the resonance load circuit 30 have a low resistance of about several Ω during the period in which the preheating current is supplied to the electrodes 8A and 8B before the discharge is started, the resonance load circuit 30 is equivalent to In other words, it can be said that it is a simple series resonance circuit of the capacitors 7 and 9 and the primary winding 10B of the transformer 10.

When the fluorescent lamp 8 is started, the inverter circuit 31 is turned on and off near the resonance frequency because a high voltage for starting the fluorescent lamp 8 needs to be generated across the capacitor 9. Then, the input impedance of the resonant load circuit 30 becomes small and a large current flows, and as a result,
A high voltage is also generated across the primary winding 10B of the transformer 10.

On the contrary, once the fluorescent lamp 8 is turned on, the discharge impedance of the fluorescent lamp 8 is inserted in parallel with the capacitor 9. At this time, the condenser 9
The discharge impedance is generally much smaller than the discharge impedance when compared with the discharge impedance. Therefore, the equivalent circuit of the resonant load circuit 30 includes the capacitor 7, the discharge impedance, and the primary winding 1 of the transformer 10.
It becomes a series circuit of 0B. Therefore, the current flowing through the resonant load circuit 30 is limited by the discharge impedance and becomes small, and as a result, the voltage across the primary winding 10B of the transformer 10 becomes very small compared to before the start of discharging.

Since a voltage proportional to the voltage generated across the primary winding 10B of the transformer 10 is generated in the secondary winding 10A, the voltage across the secondary winding 10A is also discharged by the fluorescent lamp 8. Is large before starting and becomes small after starting discharging.

As described above, the induction voltage of the secondary winding 10A causes the series resonance circuit composed of the inductor 11 and the capacitor 17 to oscillate at the resonance frequency A, and the oscillating voltage is applied to both ends of the capacitor 17. In addition, the FETs 5 and 6 are turned on / off depending on the period of the oscillating voltage. Therefore, in the period in which the amplitude of the induced voltage in the secondary winding 10A before the fluorescent lamp 8 starts to discharge increases, the amplitude of the oscillating voltage generated in the capacitor 17 also increases.

At this time, the oscillating voltage is
Since the voltage exceeds the Zener voltage of the Zener diodes 15 and 16 connected in parallel to
It is considered that 16 is turned on, and as a result, the impedance across the capacitor 17 sharply decreases. Therefore, the resonance frequency A is lowered, and the FET5,
The on / off frequency of 6 decreases. When the on / off frequency of the FETs 5 and 6 becomes significantly lower than the resonance frequency of the resonance load circuit 30, the voltage generated across the capacitor 9 decreases. As a result, the fluorescent lamp 8 may not be turned on.

Under normal conditions such that the fluorescent lamp is easy to light, even if the deviation from the resonance frequency becomes large to some extent, the lamp can often be lighted without any particular problem, but the fluorescent lamp is difficult to light. Lighting may be difficult under the conditions (for example, at a low temperature). Difficulty in lighting is one of the most serious problems for lamp users. In addition, in general, when an electrodeless discharge lamp that is difficult to light up is used as compared with a fluorescent lamp with an electrode (in particular, when metal is present around it)
Even in the case, lighting may be difficult.

In the prior art, the fluorescent lamp 8 is relatively easy to light up even under a condition that it is difficult to light up, so that the structure shown in FIG. 6 can be used to light up the fluorescent lamp 8 without any problem. did it. Therefore, the inconvenience at the time of lighting found by the inventor of the present application has not been a problem. However, even if the conventional configuration can be lit without problems, for today or tomorrow, fluorescent lamps tend to be designed to be difficult to illuminate, and the more this trend progresses, A lighting device capable of reliably lighting becomes important.

That is, for the purpose of downsizing,
Fluorescent lamps are often designed to have a smaller tube diameter, a longer distance between electrodes, or a complicated shape.The more such designs increase, the more A lighting device that can be reliably turned on has important technical significance. This also applies to the configuration of the bulb-type fluorescent lamp that can directly replace the bulb. In addition, since a self-ballasted electrodeless discharge lamp has also been developed in recent years, even if a self-ballasted electrodeless discharge lamp becomes popular as a substitute for a light bulb, even under the condition that even a fluorescent lamp with an electrode is difficult to light. It seems that there will be a strong demand for a lighting device that can reliably light an electrodeless discharge lamp.

Embodiments according to the present invention will be described below with reference to the drawings. In the following drawings, for simplification of description, components having substantially the same function are designated by the same reference numeral. The present invention is not limited to the embodiments below. (Embodiment 1) A discharge lamp lighting device according to Embodiment 1 of the present invention will be described with reference to FIGS. 1 and 2.
FIG. 1 schematically shows the configuration of the discharge lamp lighting device of the present embodiment.

The discharge lamp lighting device of this embodiment includes a DC power supply circuit section 22 for outputting a DC voltage and a switching element (5, 6) with a control terminal for converting an output from the DC power supply circuit section 22 into an AC voltage. It includes an inverter circuit 31 including the same, a control terminal drive circuit 41 for on / off controlling the switching elements (5, 6) with control terminals, and a resonance load circuit 30. The resonant load circuit includes a discharge lamp 8, a first inductor 10B, a first capacitor 7, and a capacitor 9
And have.

The control terminal drive circuit 41 includes a drive winding 10A mutually coupled to the first inductor 10B, a series circuit of a voltage clamp element (15, 16) and an impedance element 40. This series circuit consists of drive winding 1
0A, and in the present embodiment, the voltage clamp element (15, 16) is a Zener diode. As shown in FIG. 1, this Zener diode and one end of the drive winding 10A are connected to each other. The impedance element 40 is inserted between the two. In addition, the control terminal drive circuit 41 is configured to be able to perform on / off control of the switching elements with control terminals (5, 6) by the voltage generated in the drive winding 10A.

The configuration shown in FIG. 1 is the same as that shown in FIG. 6 except that the impedance element 40 is inserted in series with the Zener diodes 15 and 16 which are voltage clamp elements.
The configuration is basically the same as that shown in. Therefore, the common part between the present embodiment and the configuration shown in FIG. 6 has the same configuration.

The DC power supply circuit section 22 includes a noise prevention capacitor 2, a diode bridge 3 and a smoothing capacitor 4. In the present embodiment, the AC power supply 1 can be converted into DC and output. However, since the DC power supply circuit unit 22 may be configured to output a DC voltage, it is a DC power supply that directly outputs a DC voltage without using an AC power supply or a commercial power supply. Good.

The inverter circuit 31 has FETs 5 and 6, and the FETs 5 and 6 are switching elements with control terminals (gates). In the inverter circuit 31, the FETs 5 and 6 are alternately turned on and off to convert direct current into alternating current. The FETs 5 and 6 are on / off controlled by the control terminal drive circuit 41. The resonant load circuit 30 includes a first capacitor 7, a fluorescent lamp 8 which is a discharge lamp, a capacitor 9 for preheating the electrodes 8A and 8B of the fluorescent lamp 8, and a transformer 10 which is a first inductor. It is composed of a primary winding 10B.

Next, the outline of the operation when the impedance element 40 is inserted will be described with reference to FIG. FIG. 2 is a circuit showing a part of the control terminal drive circuit 41 of this embodiment. In FIG. 2, the AC voltage generated across the secondary winding 10A of the transformer 10 is referred to as V0.

As described above, the transformer 10 is used before the fluorescent lamp 8 starts discharging and after it starts discharging.
The voltages generated at both ends of the secondary winding 10A differ greatly. Therefore, before the discharge is started, the amplitude of V0 is large and the voltage amplitude generated in the capacitor 17 is also large,
Therefore, the Zener diodes 15 and 16 are turned on, and the current IB flows. This current IB has not been considered in the conventional configuration shown in FIG.

In the present embodiment, the impedance element 40
Is inserted, the current IB can be controlled. That is, since the current is limited by the impedance element 40, the current IB can be limited to a very small value. Therefore, in the configuration of the present embodiment, most of the output current of the power source V0 is the inductor 1
1 and capacitor 17 through. On the other hand, after the fluorescent lamp 8 starts to discharge, the amplitude of V0 becomes small, so that the voltage generated across the capacitor 17 becomes small, and as a result, the Zener diodes 15 and 16 do not turn on, or if they turn on. Since the conduction period is very short even in the state, most of the output current of the power supply V0 flows through the inductor 11 and the capacitor 17.

With the above operation, the output current of the power source V0 is mostly IA and IB can be made very small before and after the discharge of the fluorescent lamp 8 is started. Therefore, since the FETs 5 and 6 can be turned on / off at the resonance frequency of the inductor 11 and the capacitor 17, the voltage capable of reliably starting the fluorescent lamp 8 can be generated across the capacitor 9 of the resonance load circuit 30. ,as a result,
The fluorescent lamp 8 can be reliably started.

Impedance element 4 in this embodiment
0 is a resistance. If the impedance of the impedance element 40 is too small, the current IB becomes large, but as a result of verification by the inventor of the present application, if it is 10Ω or more, the fluorescent lamp 8 can be reliably started. Further, the current Ic shown in FIG. 2 is a signal current for turning on / off the FETs 5 and 6, and if Ic is too small, the loss when the FETs 5 and 6 are turned on / off increases.
Therefore, the resistance value of the impedance element 40 is 50
It is preferably 0Ω or less.

The discharge lamp lighting device of this embodiment is shown in FIG.
As shown in FIG. 3, it is possible to have a configuration of a bulb-type fluorescent lamp. FIG. 3 schematically shows the configuration of the bulb-type fluorescent lamp of this embodiment.

The bulb-type fluorescent lamp shown in FIG. 3 is a fluorescent lamp 7 in which the fluorescent lamp 8 shown in FIG. 1 is bent.
1, a base 72 such as an E26 type for incandescent bulbs, a circuit board 73 on which wiring of the lighting circuit configuration shown in FIG. 1 is formed and each circuit component 76 is attached, and the base 72 is attached to one end. It has a cover 74 that accommodates the circuit board 73 inside, and a globe 75 that is arranged so as to cover the periphery of the fluorescent lamp 71 and has a light-transmitting property. The wattage of the compact fluorescent lamp shown in FIG. 3 is 13 watts. As an example of the conditions of the fluorescent lamp 71, its tube diameter (outer diameter) is 10.75 mm, and its glass wall thickness is 0.
8 mm, and the distance between the electrodes is 300 mm.

Although not shown, the fluorescent lamp 71 and the circuit board 73, and the circuit board 73 and the base 72 are electrically connected to each other. Electric power is generated by screwing the fluorescent lamp 71 and the base 73 into the incandescent lamp socket via the base 72. When supplied, the fluorescent lamp 71 is turned on. Each circuit component 76 forming the lighting circuit is attached to the circuit board 73, but only representative components are shown in FIG.

As shown in FIG. 3, in the structure of the light bulb type fluorescent lamp, since the fluorescent lamp 71 having a relatively small tube diameter is arranged in a bent shape in a narrow space, the startability is accordingly increased. become worse. According to the configuration of the present embodiment, the fluorescent lamp 8 can be surely started even with such a compact fluorescent lamp having a relatively poor startability. It can be suitably applied to the structure of a lamp.

Further, in the bulb-type fluorescent lamp shown in FIG. 3, since the mounting area of the circuit board 73 is relatively small,
Although it is practically difficult to add or change a large amount of circuits and elements, the configuration of the present embodiment only adds a resistance as the impedance element 40, so that there is a restriction on the area for mounting the light bulb. Also in the shape fluorescent lamp,
There is also an advantage that the circuit configuration of the present embodiment can be easily realized. That is, since the resistor has a relatively small size, it can be easily mounted even on the circuit board 73 of the bulb-type fluorescent lamp having a relatively small mounting area. Further, the configuration using the resistance element is relatively simple and can be realized at low cost, and in that sense as well, there are great advantages.

As described above, in the discharge lamp lighting device of the present embodiment, the control terminal drive circuit for on / off controlling the switching element with the control terminal forming the inverter circuit is
With a simple configuration in which at least one end of the drive winding has a series circuit of a voltage clamp element and an impedance element, it is possible to generate a high voltage for starting and lighting the discharge lamp. As a result, it is possible to realize a discharge lamp lighting device capable of reliably lighting even if the discharge lamp is used in any environment.

Further, the fact that the configuration of this embodiment can be realized by a simple configuration change of adding an impedance element means that the conventional manufacturing line can be used as it is, and the cost is not so high. It is also a great advantage that a relatively inexpensive resistor can be used as the impedance element. In addition, the fact that the number of changes in the configuration is small means that it is easier to predict the operation in the changed configuration, and there is another merit that the development / verification period of the product does not need to be so long. (Embodiment 2) Next, referring to FIG. 4 and FIG.
A discharge lamp lighting device according to a second embodiment of the present invention will be described. The discharge lamp lighting device of the present embodiment is a lighting device for an electrodeless discharge lamp that does not have electrodes as a discharge lamp. FIG. 4 schematically shows the circuit configuration of this embodiment.

The DC power supply circuit section 22 and the inverter circuit 31 in the discharge lamp lighting device shown in FIG. 4 have the same construction as in the first embodiment. Further, similarly to the first embodiment, the control terminal drive circuit 56 of the present embodiment also has the Zener diode 1 which is the voltage clamp element.
A resistor 50, which is an impedance element, is connected in series with 5 and 16.
Has been inserted. The other points of the control terminal drive circuit 56 are the same as those of the control terminal drive circuit 23 shown in FIG.

The discharge lamp lighting device of the present embodiment is largely different from that of the first embodiment in the configuration of the resonance load circuit 55. This is because the discharge lamp lighting device of the present embodiment,
This is due to the feature of being a device for lighting an electrodeless discharge lamp. Since the other points are basically the same as the configuration of the first embodiment, the same description is omitted for simplification of the description.

The resonant load circuit 55 in this embodiment is
Primary winding 10B of transformer 10, which is the first inductor
And a capacitor 52 which is a first capacitor, a capacitor 51, an inductor 53, and a discharge lamp 54 having an electrodeless structure. The discharge lamp 54 is an electrodeless discharge lamp that emits light in an electromagnetic field generated by a current flowing through the inductor 53.

Before the discharge lamp 54 starts to discharge, 1
Next winding 10B, capacitors 51 and 52, and inductor 53
A high voltage is generated across the inductor 53 due to the resonance action with the inverter 53, so that a strong electromagnetic field for the discharge lamp 54 to start discharging is generated.
The FETs 5 and 6 of 1 operate on / off.

On the other hand, after the discharge lamp 54 starts to discharge, the discharge impedance is inserted in parallel with the inductor 53 in an equivalent circuit, and therefore, the discharge lamp 54 is supplied with a predetermined electric power. Inductor 5
A predetermined electromagnetic field is generated from 3.

Since the impedances at both ends of the inductor 53 are always inductive before and after the discharge lamp 54 is turned on, the capacitors 51 and 52 and the primary winding 1 of the transformer 10 are connected.
By 0B, the phase is corrected so that the input impedance of the resonant load circuit 55 becomes almost resistive. That is, the capacitors 51 and 52 and the primary winding 1 of the transformer 10
OB has a function of supplying a predetermined electromagnetic field to the discharge lamp 54 and a phase correction function of making the input impedance of the resonant load circuit 55 almost resistive.

Even in the above configuration, before the discharge lamp 54 starts discharging and after it starts discharging,
The voltages generated across the secondary winding 10A of the transformer 10 are very different.

When the resistor 50 is inserted as in this embodiment, the FETs 5 and 6 are always turned on at the resonance frequency of the inductor 11 and the capacitor 17, as in the first embodiment.
Can be turned off, resulting in inductor 53
A voltage that can surely start the discharge lamp 54 can be generated at both ends of, and the start lamp can be surely lit. The resistance value of the resistor 50 is 1 as in the first embodiment.
It is desirable that it is 0Ω or more and 500Ω or less.

Furthermore, an example of the structure when the electrodeless discharge lamp lighting device having the above structure is actually used is schematically shown. The discharge lamp lighting device shown in FIG. 5 has a structure of an electrodeless bulb-type fluorescent lamp. In other words, the discharge lamp lighting device shown in FIG. 5 is a light bulb substitute light source in which the discharge lamp lighting device having the configuration shown in FIG. 4 is integrated into a light bulb shape.

The discharge lamp 54 comprises a bulb having a recessed portion, and the inductor 53 is inserted in the recessed portion. The inductor 53 is a rod-shaped ferrite core 53.
The winding 53b is wound around a. The resonance load circuit other than the inductor 53, the control terminal drive circuit 56, the inverter circuit 31, and the DC power supply circuit unit 22 (excluding the power supply 1) are configured as a drive circuit 60 that supplies power to the inductor 53. The drive circuit 60 is arranged in the storage case 61. Then, the AC power supply (corresponding to the power supply 1 in FIG. 4) applied to the drive circuit 60 is configured to be supplied from the base 62.

Assuming the actual use of the light bulb alternative light source having the above-described structure, it may be simply inserted into the light bulb socket or may be inserted into the lighting fixture (cover) 63 with the light bulb socket. . Here, the lighting fixture 63 is a lighting cover that is separated from the electrodeless discharge lamp 54 and covers the side surface of the lamp and has an opening in the emission direction of the lamp, and is made of, for example, metal. The emission direction of the lamp is, for example, downward in the case of downlight and upward in the case of uplight.

Table 1 below shows the case without the lighting fixture 63,
It is an example of the measurement results of the reactance (L value) and resistance value (R value) of the inductor 53 when the lighting fixture 63 is made of aluminum and when the lighting fixture 63 is made of iron.

[0068]

[Table 1]

The inductor 53 is a rod-shaped ferrite core 5
Since the inductor is an open magnetic circuit configured by 3a, the presence of metal around the inductor 53 affects the magnetic flux distribution and the like.

Compared with the case where there is no lighting fixture 63, the L value is greatly reduced when the lighting fixture 63 made of aluminum is provided. On the other hand, when the lighting fixture 63 made of iron is provided, the increase in the R value is large.

The reason for this may be inferred as follows. In the case of aluminum having a low resistivity, it can be estimated that the L value decreases because the magnetic flux is shielded and the magnetic flux distribution changes. Further, in the case of iron, since the resistivity is larger than that of aluminum, the change in the magnetic flux distribution is small and the L value does not change, but it can be estimated that the R value increases because the structure is likely to cause eddy current loss.

Here, a decrease in the L value or an increase in the R value causes a decrease in the Q value of the inductor 53. When the Q value decreases,
The high voltage across the inductor 53, which is required when starting the discharge of the discharge lamp 54, decreases, and a strong electromagnetic field for the discharge lamp 54 to start the discharge is hard to be generated, so that the startability of the discharge lamp 54 is increased. make worse. That is, in the present embodiment, it is necessary to reduce the error between the resonance frequency of the resonance load circuit 55 and the ON / OFF frequency of the inverter circuit 31.

According to an experiment conducted by the inventor of the present application, the resistance 50 is 0.
In the case of Ω, even if the discharge lamp 54 can be turned on without the lighting fixture (cover) 63, the discharge lamp 54 cannot be turned on when the lighting fixture 63 is present. Further, when the resistance 50 is 10Ω or more, the discharge lamp 54 can be turned on regardless of the presence or absence of the lighting fixture 63.

As described above, the discharge lamp 54 can be reliably started with a simple structure in which the resistor 50 of 10Ω or more is inserted. If the resistance value of the resistor 50 becomes too large, the signal current for turning the FETs 5 and 6 on and off becomes too small, and the loss when the FETs 5 and 6 are turned on and off becomes large. Therefore, the resistance 50 should be 500Ω or less. Is desirable.

In each of the above embodiments, the resonant load circuits 30 and 55 may have other configurations as long as they have at least the discharge lamp, the first inductor 10B and the first capacitors 7 and 52.

Further, the DC power supply circuit section 22 is composed of the AC power supply 1
The circuit for converting an alternating current into a direct current is composed of the noise prevention capacitor 2, the diode bridge 3 and the smoothing capacitor 4 which are connected to each other. However, as described above, the configuration may simply use the direct current power source.

The inverter circuit 31 is of the half bridge type composed of the FETs 5 and 6, but may have another structure such as a one-stone inverter circuit or a full bridge inverter circuit. Although the second capacitor 17 is adopted in the present embodiment, a predetermined capacitance exists between the gate and source of the FETs 5 and 6, and the gate-source capacitance is equivalently substituted for the capacitor 17. Capacitor 1 is possible
It is possible to configure the present invention even if 7 is not provided. In the present embodiment, the second inductor 11 is adopted, but the secondary winding 10A of the transformer 10 has a predetermined reactance, and the second inductor 10A has the reactance of the secondary winding 10A. If you substitute 11
The present invention can be configured without the inductor 11 of FIG.

The preferred example of the present invention has been described above, but the description is not a limitation and various modifications can of course be made.

[0079]

According to the present invention, the control terminal drive circuit is
Since it includes a series circuit of a voltage clamp element and an impedance element, which is connected to at least one end of the drive winding, a discharge lamp lighting device capable of reliably lighting a fluorescent lamp with a simple configuration of adding an impedance element is provided. Can be realized. When the discharge lamp lighting device of the present invention is a bulb-shaped electrodeless discharge lamp, it is necessary to further reduce the error between the resonance frequency of the resonance load circuit and the on / off frequency of the inverter circuit, which is more effective. Play.

[Brief description of drawings]

FIG. 1 is a circuit configuration diagram of a discharge lamp lighting device according to a first embodiment of the present invention.

FIG. 2 is a circuit diagram showing a part of a control terminal drive circuit 41.

FIG. 3 is a configuration diagram schematically showing a configuration of a bulb-type fluorescent lamp.

FIG. 4 is a circuit configuration diagram of a discharge lamp lighting device according to a second embodiment of the present invention.

[Fig. 5] Fig. 5 is a configuration diagram schematically showing a light bulb alternative light source which is an example of actually using the discharge lamp lighting device of the second embodiment of the present invention.

FIG. 6 is a circuit configuration diagram of a conventional discharge lamp lighting device.

[Explanation of symbols]

22 DC power supply circuit section (DC power supply) 23, 41, 56 control terminal drive circuit 30,55 Resonant load circuit 31 Inverter circuit 71 fluorescent lamp 72 mouthpiece 73 circuit board 74 cover 75 gloves 76 Circuit parts

─────────────────────────────────────────────────── ─── Continuation of front page (56) References JP-A-11-345693 (JP, A) JP-A-10-172776 (JP, A) JP-A-2001-15290 (JP, A) JP-A-2000-353598 ( JP, A) JP 10-208702 (JP, A) JP 2000-285712 (JP, A) International Publication 99/067977 (WO, A1) (58) Fields investigated (Int. Cl. ⁷ , DB name) ) H05B 41/24-41/298 H05B 41/36-41/44 H02M 7 / 48,7 / 537-7/5395 F21S 2/00 F21V 1 / 00,7 / 00

Claims (2)

(57) [Claims] 1. A self-ballasted electrodeless discharge lamp in which an electrodeless discharge lamp, a lighting circuit for supplying electric power to the electrodeless discharge lamp, and a base are integrally formed, wherein the lighting circuit is provided in the base. A DC power supply circuit section that is electrically connected and outputs a DC voltage, and an n-type FET and a p-type switching element with a control terminal that converts an output from the DC power supply circuit section into an AC voltage.
Type FET , an inverter circuit including a control FET, a control terminal drive circuit for ON / OFF controlling the switching element with a control terminal, the electrodeless discharge lamp, a first inductor, and a first capacitor The control terminal drive circuit includes a drive winding interconnected with the first inductor, a voltage clamp element connected to at least one end of the drive winding, and a series circuit including a resistor. , parallel to the series circuit of the resistor and the voltage clamp element
A second capacitor connected in series, the second inductor further including a second inductor;
Formed by the drive winding and the second capacitor
And a closed circuit configured to generate the voltage clamp element in the second capacitor.
Is an element that conducts when an alternating current signal that exceeds a predetermined value is generated, and resonates the second capacitor and the second inductor.
ON / OFF control of the switching element with the control terminal
The resistor limits the current flowing through the voltage clamp element.
The second capacitor and the second capacitor.
The resonant frequency determined by the inductor is prevented from changing.
A self- ballasted electrodeless discharge lamp. Wherein further, said electrodeless discharge lamp, the lighting covers circuit and the mouthpiece, light cover having an opening is provided in the outgoing direction, self-ballasted electrodeless discharge lamp according to claim 1.