JP3315398B2 - Discharge lamp lighting device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a discharge lamp lighting device. In particular, it relates to a discharge lamp lighting device for lighting and dimming a fluorescent lamp.

[0002]

2. Description of the Related Art Fluorescent lamps have been widely used mainly for home lighting since they have characteristics of higher efficiency and longer life than incandescent lamps. In particular, light bulb-type fluorescent lamps are attracting attention and becoming popular because they can be directly substituted for incandescent light bulbs.

[0003] Recently, there has been a need for dimming fluorescent lamps as well as incandescent lamps, and to meet this need, dimmable fluorescent lamps have been developed. In the case of incandescent lamps that are not discharge lamps, dimming is relatively easy if the lamp power is controlled,
In the case of a fluorescent lamp, which is a discharge lamp, dimming cannot be satisfactorily performed simply by controlling the lamp power. Therefore, when dimming a fluorescent lamp, a lighting circuit that inputs an AC voltage whose phase is controlled and enables dimming lighting is required.

FIG. 11 shows a circuit configuration of a conventional discharge lamp lighting device capable of dimming lighting. The lighting device shown in FIG. 11 includes a discharge lamp 12 and a drive circuit 26,
The drive circuit 26 includes the DC power supply 4 and the DC / AC conversion circuit 1
0 and a control circuit 16.

[0005] The DC power supply 4 rectifies the commercial AC power supply 1 by the diode bridge 2, and then rectifies the smoothing capacitor 3.
To output a DC voltage. A series circuit of power MOSFETs 5 and 6, which are main switching elements, is connected in parallel to the DC power supply 4, and a power MOSFET
Between the drain terminal and the source terminal of the ET 6, a discharge lamp 12, a resonance inductor 7, a resonance capacitor 8,
An LC resonance circuit including a capacitor 9 for supplying resonance and preheating current is connected.

The DC / AC conversion circuit 10 is a power MOS
It comprises FETs 5 and 6, a resonance inductor 7, a resonance capacitor 8, and a capacitor 9 for energizing resonance and preheating current. The control circuit 16 includes a power supply unit including a power supply resistor 13 and a zener diode 14 connected to the DC power supply 4, and a control circuit unit 15.
The control circuit unit 15 is connected to the power MOSFETs 5 and 6, and varies the power supplied to the discharge lamp 12 by varying the oscillation frequency or ON duty of these switching elements. The control circuit 16 including the control circuit unit 15 controls the discharge lamp 12 according to the dimming command signal.
The power supplied to the discharge lamp is variably controlled, thereby controlling the luminous flux of the discharge lamp to perform dimming.

[0007]

FIG. 12 is a graph schematically showing a dimming state of a conventional discharge lamp lighting device. The horizontal axis in FIG. 12 indicates the dimming command, while the vertical axis indicates the luminous flux level of the discharge lamp that changes according to the dimming command.

FIG. 12 shows that dimming can be performed by variably controlling the lamp power (curve B) according to the dimming command. However, when the dimming command is set to the low luminous flux dimming side in order to lower the luminous flux, there is a problem that unstable discharge occurs. The reason why unstable discharge occurs is assumed to be as follows. In other words, in the low luminous flux dimming region, it is necessary to control the supply power (lamp power) to be small, and therefore, it is necessary to reduce the lamp current. However, this also results in a very high lamp voltage (curve A) as shown in FIG. When the lamp voltage becomes extremely high and exceeds the operation limit of the circuit, the circuit operation becomes unstable, thereby causing unstable discharge such as a blinking phenomenon of the light emitting lamp. As a result, a stable dimming operation cannot be performed from the all-light state to the extinguished state, and an unstable discharge generation region indicated by a hatched portion in FIG. 12 occurs. Lighting in the unstable discharge generation region causes flickering and flickering, and in some cases, causes troubles such as breakage of the circuit during low light flux dimming operation.

The present invention has been made in view of the above points, and a main object of the present invention is to provide a discharge lamp lighting device which can realize a stable dimming operation from an all-light state to a light-off state with a simple circuit configuration. To provide.

[0010]

A discharge lamp lighting device according to the present invention is a discharge lamp lighting device provided with a discharge lamp and a drive circuit for the discharge lamp, wherein the drive circuit includes a drive circuit for the discharge lamp. The power supply can be varied, and the discharge lamp has a function of turning off the discharge lamp at a supply power value higher than a supply power value at which unstable discharge occurs in the discharge lamp.

In one embodiment, the driving circuit comprises:
What is claimed is: 1. A DC / AC conversion circuit comprising: a DC power supply; and a switching element for converting an output of the DC power supply into an alternating current, the DC / AC conversion circuit having an output terminal connected to the discharge lamp, and an oscillation of the switching element. A control circuit that varies a frequency or an ON duty and thereby variably controls power supplied to the discharge lamp; a lamp characteristic detection circuit that detects that a value of power supplied to the discharge lamp is a predetermined value; A stop circuit for generating a signal for stopping the operation of the control circuit if the value is a value.

Preferably, the lamp characteristic detecting circuit has a delay circuit for delaying an output signal by a predetermined time.

In one embodiment, the stop circuit includes:
A circuit for generating a signal for stopping the operation of the control circuit while the output signal of the lamp characteristic detection circuit is being input.

[0014] In one embodiment, the discharge lamp lighting device is configured as a bulb-type fluorescent lamp.

In one embodiment, the driving circuit comprises:
The power supplied to the discharge lamp can be varied continuously or discretely, thereby dimming the discharge lamp continuously or discretely.

Another discharge lamp lighting device according to the present invention comprises:
A discharge lamp lighting device including a discharge lamp and a drive circuit for the discharge lamp, wherein the drive circuit can vary power supplied to the discharge lamp, and generates an unstable discharge in the discharge lamp. The discharge lamp lighting device has a function of turning off the discharge lamp at a supply power value higher than the supply power value, and further, the discharge lamp lighting device has a function of controlling the discharge lamp regardless of the dimming level of the discharge lamp lighting device. It has means for supplying the supply power in the dimming level in the all-light state for a certain period.

In one embodiment, the driving circuit comprises:
What is claimed is: 1. A DC / AC conversion circuit comprising: a DC power supply; and a switching element for converting an output of the DC power supply into an alternating current, the DC / AC conversion circuit having an output terminal connected to the discharge lamp, and an oscillation of the switching element. A control circuit that varies a frequency or an ON duty and thereby variably controls power supplied to the discharge lamp; a lamp characteristic detection circuit that detects that a value of power supplied to the discharge lamp is a predetermined value; A stop circuit for generating a signal for stopping the operation of the control circuit if the value is a value. A timer circuit that operates for a period, and generates an all-light dimming command signal that sets the dimming level to the level of the all-light state in accordance with the output from the timer circuit, An all-light dimming command signal output unit for outputting to the control circuit, wherein the control circuit discharges the all-light dimming command signal from the all-light dimming command signal generating unit to the discharge direction. Has a function to process in preference to the dimming command signal for variably controlling the power supplied to the lamp,
Thereby, the discharge lamp is supplied with electric power in an all-light state.

According to the present invention, the drive circuit has a function of changing the power supply to the discharge lamp and turning off the discharge lamp at a power supply value higher than the power supply value at which unstable discharge occurs in the discharge lamp. With this configuration, the dimming can be performed by varying the power supplied to the discharge lamp, and the discharge lamp can be turned off at a predetermined power supply value. As a result, the occurrence of unstable discharge in the discharge lamp can be avoided, so that a stable dimming operation from the all-light state to the unlit state can be realized. The lamp characteristic detection circuit included in the drive circuit
When a delay circuit for delaying the output signal by a predetermined time is provided, it is possible to prevent a malfunction caused by a high-voltage pulse generated at the time of starting and lighting the discharge lamp. In addition, when the stop circuit included in the drive circuit is a circuit that generates a signal for stopping the operation of the control circuit while the output signal of the lamp characteristic detection circuit is being input, a complicated circuit that holds the stop signal A stop circuit can be realized with a simple configuration that does not require a reset circuit or the like.

[0019]

Embodiments of the present invention will be described below with reference to the drawings. Note that the present invention is not limited to the following embodiments.

FIG. 1 shows a circuit configuration of a discharge lamp lighting device according to an embodiment of the present invention. The discharge lamp lighting device of the present embodiment includes the discharge lamp 12 and a drive circuit 27 for the discharge lamp 12.
Has a function of changing the supply power to the discharge lamp 12 and turning off the discharge lamp 12 at a supply power value higher than a supply power value at which unstable discharge occurs in the discharge lamp 12. Since the drive circuit 27 has such a function, it is possible to realize a lighting circuit of a discharge lamp capable of performing a stable dimming operation without an unstable discharge from an all-light state to an unlit state. That is, in an area where unstable discharge occurs (an unstable discharge generation area), the discharge lamp 12 is turned off to prevent the occurrence of flickering and blinking.

The discharge lamp driving circuit 27 shown in FIG.
Comprises a DC power supply 4, a DC / AC conversion circuit 10, a control circuit 16, a lamp characteristic detection circuit 22, and a stop circuit 25. Mainly, the lamp characteristic detecting circuit 22 and the stop circuit 25 are adapted to supply the discharge lamp 12 with a supply power value higher than a supply power value at which unstable discharge occurs in the discharge lamp 12.
Plays the role of turning off the light.

More specifically, the drive circuit 27 of the present embodiment includes a DC / AC power supply including a DC power supply 4 and switching elements (5, 6) for converting an output of the DC power supply 4 into an AC power.
And a conversion circuit 10. DC / AC conversion circuit 10
Is connected to a discharge lamp 12. The switching elements (5, 6) are connected to the control circuit 16, and the control circuit 16 varies the oscillation frequency or the ON duty of the switching elements (5, 6) according to the dimming command signal, thereby discharging. The power supplied to the lamp 12 is variably controlled. The discharge lamp 12 is connected to a lamp characteristic detection circuit 22, and the lamp characteristic detection circuit 22
It detects that the value of the power supplied to the discharge lamp 12 is a predetermined value. A stop circuit 25 is connected to the lamp characteristic detection circuit 22. The stop circuit 25 generates a signal for stopping the operation of the control circuit 16 when the value of the power supplied to the discharge lamp 12 is a predetermined value. Output to the circuit 16.

The DC power supply 4 rectifies the commercial AC power supply 1 by the diode bridge 2 and then smoothes it with the smoothing capacitor 3 to output a DC voltage, similarly to the configuration shown in FIG. A series circuit of power MOSFETs 5 and 6, which are main switching elements, is connected in parallel to the DC power supply 4, and a discharge lamp 12, a resonance inductor 7, a resonance inductor 7, An LC resonance circuit including a capacitor 8 and a capacitor 9 for supplying resonance and preheating current is connected.

Similarly to the configuration shown in FIG. 11, the DC / AC conversion circuit 10 includes power MOSFETs 5 and 6, an inductor 7 for resonance, a capacitor 8 for resonance, and a capacitor 9 for energizing resonance and preheating current. It is configured. The control circuit 16 includes a power supply unit including a power supply resistor 13 and a zener diode 14 connected to the DC power supply 4, and a control circuit unit 15. The control circuit unit 15 is connected to the power MOSFETs 5 and 6, and varies the power supplied to the discharge lamp 12 by varying the oscillation frequency or ON duty of these switching elements. The control circuit 16 including the control circuit unit 15 can variably control the power supplied to the discharge lamp 12 according to the dimming command.

As described above, the lamp characteristic detecting circuit 22 has a function of detecting that the value of the power supplied to the discharge lamp 12 is a predetermined value. The lamp characteristic detecting circuit 22 of the present embodiment includes a resistor 17, a resistor 18, a diode 1
9, a capacitor 20, and a resistor 21. To detect the power supplied to the discharge lamp 12, a resistor 17
A series circuit of a discharge lamp 12 and a resistor 18 is connected in parallel to both ends of the discharge lamp 12. As shown in FIG. 12, there is a correlation between the supplied power and the voltage across the discharge lamp,
Utilizing this, in the configuration of the present embodiment, the voltage obtained by dividing the voltage of the discharge lamp by the resistance ratio of the resistor 17 and the resistor 18 is detected, and thereby the supplied power is detected. With such a configuration, there is an advantage that the circuit configuration can be simplified as compared with the case where the supplied power is directly detected. Although the circuit configuration becomes complicated, it is of course possible to detect the lamp current and detect the lamp supply power.

Since a series circuit of a diode 19 and a capacitor 20 is connected to both ends of the resistor 18, the voltage of the discharge lamp divided by the resistor 18 is charged to the capacitor 20 via the diode 19. Is done. Here, the resistor 17 and the capacitor 20 form a delay circuit, thereby giving a time delay to the charging time of the capacitor 20. The delay circuit between the capacitor 20 and the resistor 17 has a function of preventing a stop circuit from erroneously operating due to a high-voltage pulse generated when the discharge lamp is started and lit. In other words, the delay circuit plays a role of operating the stop circuit in the unstable discharge generation region while preventing the stop circuit from operating when the discharge lamp is started and lit. The detailed operation of the delay circuit will be described later. Note that the resistor 21 connected in parallel with the capacitor 20 is a discharging resistor of the capacitor 20.

The stop circuit 25 includes a Zener diode 23
And a transistor 24 which is a switching element. When the charging voltage of the capacitor 20 becomes higher than the total voltage of the Zener voltage of the Zener diode 23 and the forward voltage between the base and the emitter of the transistor 24 as a switching element, the transistor 2
4, a base current flows, and the transistor 24 is turned on. The turned-on transistor 24 short-circuits the connection point between the power supply resistor 13 of the control circuit 16 and the Zener diode 14 to the minus terminal of the DC power supply 4, thereby stopping the power supply to the control circuit unit 15. Power MOS
The switching of the FETs 5 and 6 is stopped. as a result,
The power supplied to the discharge lamp 12 is lost, and the discharge lamp 1
2 can be turned off.

The operation of the discharge lamp lighting device according to the configuration of this embodiment is, for example, as shown in FIG. FIG. 2 is a graph schematically showing a dimming state of the discharge lamp lighting device of the present embodiment. The horizontal axis in FIG. 2 shows the dimming command, while the vertical axis shows the luminous flux level of the discharge lamp that changes according to the dimming command. Curve A in FIG. 2 shows the lamp voltage, and curve C shows the luminous flux. Point B is a point where the discharge lamp is turned off when the lamp voltage reaches this point or higher so that the operation of the discharge lamp does not enter the unstable discharge generation region. Point B can be defined by setting circuit constants of the lamp characteristic detection circuit 22 in advance.

As shown in FIG. 2, when the luminous flux of the discharge lamp 12 is lowered by dimming from the all-light (100%) state, the lamp characteristic detecting circuit 22 detects the voltage at the point B, and the stop circuit 25 is activated. The discharge lamp 12 is turned off by operating. That is, the luminous flux of the discharge lamp 12 corresponding to the point B is
The dimming lighting lower limit luminous flux value (point D) is reached, and in the dimming region below the point D, the discharge lamp 12 is turned off.

Even when the dimming command corresponding to the points B and D is further lowered, the light-off state still continues. That is, also at this time, the oscillation frequency or ON duty of the switching element is changed by the dimming command signal, and the power supplied to the discharge lamp is reduced, so that the lamp voltage required for lighting the light-emitting lamp is: It cannot be obtained and the light-off state continues. This extinction state can be realized by the stop circuit 25 that continuously generates a signal (stop signal) for stopping the operation of the control circuit 16 while the output signal of the lamp characteristic detection circuit 22 is input to the stop circuit 25. Alternatively, it can be realized by a stop circuit 25 that can hold a stop signal.

As described above, according to the discharge lamp lighting device of the present embodiment, it is possible to avoid the unstable discharge that has occurred in the low luminous flux dimming region. A stable dimming operation can be realized.

Next, the operation of the discharge lamp lighting device in which unstable discharge can occur will be described with reference to FIG. FIG. 3 is a graph showing an example of a lamp voltage change during dimming. The horizontal axis in FIG. 3 represents the light output (%), and the vertical axis represents the lamp voltage (V; effective value). The lamp voltage, since it represents the effective value, when converted to the lamp voltage V _pp is 2 × (2) may be multiplied ^1/2 the effective value of the lamp voltage (V). In addition, each point in FIG. 3 was obtained by an experiment performed by the inventor of the present application.

As can be seen from FIG. 3, when the light output is lowered from the all-light state by dimming, the lamp voltage gradually increases. In dimming the light output up to 10%, the lamp voltage (V) rises gently, but falls sharply below 10%. Since this rapidly rising range is an unstable discharge generation region, in this example, the lamp characteristic detecting circuit 22 may be set so that the stop circuit 25 is activated when the range falls below 10%.

Next, instead of the commercial AC power supply 1 having the waveform shown in FIG. 4A (see FIG. 1), an external phase control device (for example, a dimmer for incandescent current) is used.
An example in which the discharge lamp 12 is dimmed by using an AC voltage whose phase is controlled as shown in FIG. 4B and changing the ON time width of the AC voltage will be described.

FIG. 5 shows the relationship between the ON time width (mS), the lamp voltage (Vla) and the lamp current (Ila). Lamp voltage in FIG. 5, rather than the lamp voltage effective value shown in FIG. 3 shows a lamp voltage V _pp. In FIG. 5, since the lamp current is also shown in addition to the lamp voltage, a change in the supplied power with respect to the ON time width (mS) can be easily derived from both the lamp voltage and the lamp current.

As can be understood from FIG. 5, when the ON time width is lowered from the all-light state (100% dimming) of about 6.5 mS, the lamp is fixed (linearly) at a constant rate with respect to the ON time width. The current (Ila) decreases. On the other hand, the lamp voltage (Vla) is 38 when the ON time width is approximately 2.5 mS.
It gradually increases to 0 V _pp (Ila = 40 mA), but when it exceeds 380 V _pp , the lamp voltage (Vla)
Is suddenly increased, it becomes _{480V p -p (Ila = 10mA)} . In the case of this example, the range where the lamp voltage exceeds 380 V _pp is an unstable discharge occurrence area. Therefore, the dimming point before the area becomes the area, for example, the ON time width is about 2.5 mS.
In this regard, the circuit may be configured to stop the lighting of the discharge lamp 12. It is also preferable to configure the circuit so as to stop the lighting of the discharge lamp 12 at a point where the dimming state is about 10% (about 2.7 mS) in consideration of product variation and a margin. The point at which the lighting of the discharge lamp 12 is stopped can be determined as appropriate from lamp characteristics, circuit characteristics, intended use, and the like.
If necessary for the purpose of use, the lighting of the discharge lamp 12 may be stopped at the point where the dimming state is 3% or 5%. The inventor of the present application has confirmed through experiments that the occurrence of unstable discharge can be suppressed even when the lighting of the discharge lamp 12 is stopped when the dimming state is 5%.

Next, the device configuration of the present embodiment will be described.
As shown in FIG. 6, the discharge lamp lighting device of the present embodiment can be configured as a bulb-type fluorescent lamp. FIG. 6 shows a compact fluorescent lamp (22 W class) according to the present embodiment.
Is schematically shown.

The light bulb-type fluorescent lamp shown in FIG. 6 has a discharge lamp (fluorescent lamp) 12 shown in FIG. 1 with a bent shape, a base 52 such as E26 type for an incandescent lamp, and the like. Circuit board 5 on which wiring of the configuration of the lighting circuit shown in FIG. 1 is formed and each circuit component 56 is attached
3, a base 52 is attached to one end, and a circuit board 5 is provided inside.
3 and a translucent glove 55 disposed to cover the periphery of the fluorescent lamp 51. The globe 55 may be omitted, and a base other than the incandescent lamp E26 type may be used. Although each circuit component 56 constituting the lighting circuit is attached to the circuit board 53, FIG. 6 shows only typical components.

Although not shown, the fluorescent lamp 51 and the circuit board 53 and the circuit board 53 and the base 52 are electrically connected to each other, and power is supplied by screwing into the incandescent lamp socket via the base 52. When supplied, the fluorescent lamp 51 is turned on. The AC voltage input through the base 52 is an AC voltage whose phase is controlled by an external phase control device (for example, a dimmer for an incandescent lamp).

When dimming the fluorescent light bulb (discharge lamp lighting device) shown in FIG. 6, for example, a dimmer installed on the wall of a room where the lamp is installed or a remote-control type dimmer is used. The light control may be performed by using this. Discharge lamp 12
Drive circuit 27 so that the power supplied to the
Can be configured, or can be configured to be discretely variable, so that the dimming by the dimmer is continuous, for example, through a range of 100% to 10% of the dimming command. It may be a discrete one (for example, a dimming instruction of 100%, 90%... 10%). The continuous type has an advantage that the dimming can be arbitrarily performed, and the discrete type has an advantage that the dimming can be easily performed to obtain a desired constant brightness. In the present embodiment, as the dimmer, a volume type phase control type or an electronic type phase control type can be used. In the case of the electronic phase control type, it is easy to make a configuration (a dimmer with a dimming storage function) provided with a function of storing the brightness of the user's preference, so A satisfying lighting fixture can be realized.

Next, with reference to FIG. 7, a specific example of an unstable discharge generation region which is problematic in the prior art will be described. FIG. 7A shows a bulb-type fluorescent lamp (22W class).
And an unstable discharge generation area when a volume type phase control type is used as a dimmer for dimming the light. On the other hand, FIG. 7B shows a bulb-type fluorescent tube (22W class) and an unstable discharge generation region (dotted line) when an electronic phase control type is used as a dimmer. FIG.
In the case of (b), although the reason is not clear, there are two different areas as an unstable discharge generation area (dotted line area): a blinking area (shiny) and a flickering area (flicker).
Here, “blinking” means a phenomenon that the user feels that the lamp is on or off, and “flicker”
Means a phenomenon that is not perceived as a steady stimulus when a change in light enters the eye in a relatively small cycle.

In this embodiment, the dimming state is, for example, 10%.
If the stop circuit 25 is operated when the time is less than the predetermined time, it is possible to avoid all the unstable discharge occurrence areas including the two areas of the blinking area and the flickering area. In the case of an AC discharge lamp, if it is strictly measured with a measuring instrument, it can be said that there is no flicker completely in the area other than the unstable discharge area, What is necessary is just to design so that the stop circuit 25 may be operated on the basis of the level which does not exist. In the present embodiment, a configuration in which the discharge lamp 12 is turned off at a supply power value higher than a supply power value at which all unstable discharges occur has been described. ) To avoid a part of the unstable discharge generation region (for example, a blinking region and a part of the flickering region), and to allow another region (for example, a part of the flickering region). A configuration is also possible. A configuration that avoids only such a part of the unstable discharge generation region is also included in the scope of the present invention.

Next, the operation of the delay circuit included in the lamp characteristic detecting circuit 22 will be described with reference to FIGS. 8 (a) and 8 (b). 8 (a) is, among the circuit shown in FIG. 1, a discharge lamp 12, the lamp characteristics detecting circuit 22 shows a circuit configuration of a portion including a stop circuit 25. Figure 8
(B), when dimming from the all-light state to the minimum dimming state,
6 is a graph for explaining that a ramp voltage (Vla) is delayed by a delay circuit.

As shown in FIG. 8B, when dimming is performed from the total light to the minimum dimming, the lamp voltage (Vla) increases. The lamp voltage (Vla; curve A ₀ ) rises due to such dimming as shown in FIGS. 2, 3 and 5. Lamp voltage (Vla; curve A ₀ )
Is a voltage divided by resistors 17 and 18 (V
r; curve A ₁ ), and then delayed by a resistor 17 and a capacitor 20 to obtain Va (curve A ₂ )
Becomes Va (curve A ₂ ) is applied to the transistor 24 (Q
Unless the threshold voltage (Vbe + Vzd) of 1) is exceeded, the transistor 24 (Q1) is in the OFF state.
(Q1) is turned on, and the discharge lamp 1
2 goes out. Thus, the discharge lamp voltage (Vla)
Rises, and with that, V with a time delay
When the voltage a exceeds the threshold voltage (Vbe + Vzd), the transistor 24 (Q1) turns on and turns off.

If the Va voltage does not have a time delay in a configuration without a delay circuit, a steep high voltage (1.5 KV or more) generated at the time of starting and lighting the lamp causes a stop circuit to be activated every time the lamp is started. Therefore, the discharge lamp 12 is turned off. In the present embodiment, since the Va voltage having a time delay due to the time constant of R17 and C20 is used, such inconvenience can be avoided. That is, the delay time makes it possible to prevent the stop circuit 25 from operating with respect to the lamp voltage (Vla) at the time of starting lighting that rises sharply and falls sharply. In other words, the lamp voltage (V1
In accordance with a), the stop circuit 25 can be prevented from operating by causing the Va voltage with a time delay to drop before exceeding the threshold voltage. If Vla never exceeds the threshold voltage during start-up lighting, the stop circuit 25 does not operate and the start-up lighting is performed appropriately. The operation at the time of starting lighting will be described in more detail with reference to FIG.

[0046] Figure 9 is the delay circuit shown in FIG. 8 (a), stop circuit 25 during lamp start lighting is a graph for explaining that not operate. When starting the discharge lamp 12, a steep high voltage (curve A ₀ ) is first applied. This voltage is about 1.5 KV for about 50 μS.
, And once the discharge lamp 12 is turned on, the voltage is stabilized at about 200V. As the starting voltage of the curve A ₀ increases, the resistance divided voltage (Vr; curve A
_{Although 1} ) also rises sharply and exceeds the B ₀ point, the resistance divided voltage immediately falls below the threshold voltage (Vth) as the starting voltage of the curve A ₀ falls. The Va voltage (curve A ₂ ) with a time delay in the resistance divided voltage is initially
Vth increases toward the point B of the Vth, but as the resistance divided voltage decreases, the Va voltage decreases without reaching the point B. Therefore, the Va voltage does not exceed Vth. In this way, by configuring the delay circuit so that the Va voltage does not exceed Vth at the time of starting the lamp, the stop circuit 25 is operated properly at the time of dimming and the malfunction is prevented at the time of starting the lamp. It can be operated.

[0047] Therefore, when setting the constants of the circuit shown in FIG. 8 (a), adjustment in the optical gradual Vla voltage change at a predetermined voltage (for example, Q1 of Vth) stops to be equal to or greater than While operating the circuit 25,
It is preferable to design the circuit so that the circuit does not operate at a steep high voltage and a steep fall at the time of starting lighting. In this embodiment, R17 = 272kΩ, by the time constant of C20 = 1 .mu.F, have set a time delay B ₀ points → B point 0.272 seconds. If other circuit constants of the present embodiment are shown, R18
= 6.8 kΩ and R21 = 1 MΩ. Further, the Zener voltage Vzd = 8.2V, Vbe = 0.6V, and Q1
(That is, Vzd + Vbe) is 8.8V. Therefore, in the circuit configuration of the present embodiment, when Va reaches 8.8 V, Q1 turns ON, and the discharge lamp 1
2 goes out. Note that the circuit constants of the present embodiment are mere examples, and the circuit constants may be appropriately set according to the lamps and circuits used.

As described above, according to the discharge lamp lighting device of the present embodiment, a stable dimming operation from the all-light state to the unlit state can be realized with a simple circuit configuration.

Next, a modified example of the discharge lamp lighting device of the present embodiment will be described with reference to FIG. In the case of the discharge lamp lighting device of the embodiment shown in FIG. 1, the AC power supply 1 is in a state where the dimming level of the dimmer is reduced to, for example, 50% or less, that is, in a state where the dimming command is set to 50% or less.
And then turning on the AC power supply 1 again, the discharge lamp 12 may not be lit again. This is because the dimming command signal lowers the dimming level, so that the lamp voltage (break voltage) required for starting and lighting the lamp may not be obtained.

For the user, the AC source 1 is turned on.
Usually, it is considered that the discharge lamp 12 is turned on regardless of the dimming level of the dimmer. For this reason, when the dimming level of the dimmer is low, the fact that the AC power supply 1 cannot be turned on again is a serious problem for the user.
Therefore, the inventor of the present application has provided the lighting device shown in FIG. 1 with a function of supplying a supply power in a dimming level to the discharge lamp 12 for a certain period, regardless of the dimming level of the dimmer. By adding it, the above problem was avoided. FIG. 10 shows an example of a circuit configuration having such a function.

The lighting device shown in FIG. 10 operates in accordance with a switch 28 for turning on the AC power supply 1 and operates for a fixed period (for example, 2 to 5 seconds). All light dimming command signal (100%
All-light dimming command signal generating section 30 for generating a dimming command signal)
And The control circuit unit 15 of the lighting device is configured to give priority to the all-light dimming command signal 31 output from the all-light dimming command signal generating unit 30 over the normal dimming command signal 32. I have. According to this configuration, the light control level of the light control command signal 32 is low (for example, 50% to 50%).
Even if the AC power supply 1 is stopped at 20%) and then turned on again, the lamp voltage required for starting and lighting the lamp is obtained by the all-light dimming command signal 31 for a certain period of time (for example, 2 to 5 seconds). . Therefore, even if the normal light control command signal 32
Is low, the discharge lamp 12 can be restarted.

As described above, according to the modification of this embodiment,
In addition to the effects of the above-described embodiment, an effect that relighting can be easily performed regardless of the dimming level of the dimmer can be obtained.

In the above-described embodiment, the device configuration of the bulb-type fluorescent lamp has been described. However, it is needless to say that the present invention is not limited to this device configuration. Is also good. The discharge lamp 12 is not limited to a fluorescent lamp, but may be a high-pressure discharge lamp.

The configurations of the lamp characteristic detecting circuit 22 and the stop circuit 25 are not limited to the above-described configurations as long as each required function is provided. Further, the transistor 2 of the stop circuit 25
4 is a switching element, a thyristor or a MOSF
An ET transistor may be used, or another transistor may be used.
Similarly, other switching elements may be used for the power MOSFETs 5 and 6.

In addition, instead of the commercial AC power supply 1 used for the DC power supply 4, an AC power supply whose phase is controlled as described above may be used. Also, in the above embodiment,
Although the power supply section of the control circuit 16 is stopped by the stop circuit 25 to stop the switching of the power MOSFETs 5 and 6, the oscillation circuit of the control circuit section 15 may be stopped directly, or the frequency may be changed by a discharge lamp or the like. The switching may be stopped at a higher frequency than the resonance frequency of the LC resonance circuit including

[0056]

According to the present invention, the power supply to the discharge lamp can be varied, and the function of turning off the discharge lamp at a supply power value higher than the supply power value at which unstable discharge occurs in the discharge lamp is driven. Since the circuit is provided, it is possible to provide a discharge lamp lighting device capable of performing a stable dimming operation without an unstable discharge from an all-light state to an unlit state.

Further, regardless of the dimming level of the discharge lamp lighting device, if the discharge lamp has a means for supplying the supply power of the dimming level in the all-light state for a certain period, re-lighting is performed. A discharge lamp lighting device that can be easily executed can be realized. When the discharge lamp lighting device is configured as a bulb-type fluorescent lamp, it can be replaced with an incandescent lamp, so that the discharge lamp lighting device of the present invention can be applied to a wide range.

[Brief description of the drawings]

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

FIG. 2 is a graph for explaining the operation of the discharge lamp lighting device according to the embodiment.

FIG. 3 is a graph showing a relationship between a light output (%) and a lamp voltage (V) of the discharge lamp lighting device according to the embodiment.

FIGS. 4A and 4B are graphs each showing a waveform of an AC power supply.

FIG. 5 is a graph showing a relationship between an ON time width (mS) and a lamp voltage (V _pp ) for the discharge lamp lighting device according to the present embodiment.

FIG. 6 is a diagram schematically showing a configuration of a bulb-type fluorescent lamp of the present embodiment.

FIGS. 7A and 7B are graphs showing a relationship between a dimming command and a light flux amount.

FIG. 8A is a diagram for explaining a circuit configuration of the present embodiment. (B) is a graph for explaining the operation of the delay circuit / stop circuit at the time of dimming.

FIG. 9 is a graph for explaining the operation of a delay circuit / stop circuit at the start of lamp lighting.

FIG. 10 is a configuration diagram for explaining a modification of the lighting device of the discharge lamp according to the embodiment.

FIG. 11 is a configuration diagram of a conventional discharge lamp lighting device.

FIG. 12 is a graph illustrating the operation of a conventional discharge lamp lighting device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 DC / AC conversion circuit 12 Discharge lamp 15 Control circuit part 16 Control circuit 22 Lamp characteristic detection circuit 25 Stop circuit 26, 27 Drive circuit 29 Timer circuit 30 All light dimming command signal generation part 51 Fluorescent lamp 52 Base 53 Circuit board 54 Cover 55 Glove 56 Circuit parts

──────────────────────────────────────────────────の Continuing on the front page (72) Inventor Kouji Miyazaki 1006 Kazuma Kadoma, Osaka Prefecture Inside Matsushita Electric Industrial Co., Ltd. (56) References JP-A-9-245979 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) H05B 41/392

Claims (8)

(57) [Claims] 1. A discharge lamp lighting device comprising a discharge lamp and a drive circuit for the discharge lamp, wherein the drive circuit controls power supplied to the discharge lamp in a phase-controlled manner.
It can be varied depending on your AC voltage, and, whether all light conditions
Dimming operation without unstable discharge from light to off state
A discharge lamp lighting device having a function of turning off the discharge lamp at a supply power value higher than a supply power value at which unstable discharge occurs in the discharge lamp. 2. The DC / AC conversion circuit, comprising: a DC power supply; and a switching element for converting an output of the DC power supply into an alternating current, the DC / AC conversion circuit having an output terminal connected to the discharge lamp. An AC conversion circuit, a control circuit that varies an oscillation frequency or an ON duty of the switching element according to a phase-controlled AC voltage , thereby variably controlling power supplied to the discharge lamp, and supply to the discharge lamp. The discharge lamp according to claim 1, further comprising: a lamp characteristic detection circuit that detects that the power value is a predetermined value; and a stop circuit that generates a signal that stops the operation of the control circuit if the power value is the predetermined value. Lighting device. 3. The discharge lamp lighting device according to claim 2, wherein said lamp characteristic detecting circuit has a delay circuit for delaying an output signal by a predetermined time. 4. The discharge according to claim 2, wherein the stop circuit is a circuit that generates a signal for stopping the operation of the control circuit while the output signal of the lamp characteristic detection circuit is being input. Lamp lighting device. 5. The discharge lamp lighting device according to claim 1, wherein the discharge lamp lighting device is configured as a bulb-type fluorescent lamp. 6. The driving circuit is capable of continuously or discretely varying the power supplied to the discharge lamp, thereby dimming the discharge lamp continuously or discretely.
The discharge lamp lighting device according to claim 1. 7. A discharge lamp lighting device comprising a discharge lamp and a drive circuit for the discharge lamp, wherein the drive circuit controls power supplied to the discharge lamp in phase.
It can be varied depending on your AC voltage, and, whether all light conditions
Dimming operation without unstable discharge from light to off state
And to have the function unstable discharge in the discharge lamp to turn off the discharge lamp in the supply power value above the supply power value generated, further, the discharge lamp lighting device, the discharge lamp lighting A discharge lamp lighting device, comprising: means for supplying power to the discharge lamp at a dimming level of an all-light state for a certain period, regardless of the dimming level of the device. 8. The DC / AC conversion circuit, comprising: a DC power supply; and a switching element for converting an output of the DC power supply into an alternating current, the DC / AC conversion circuit having an output terminal connected to the discharge lamp. An AC conversion circuit, a control circuit that varies an oscillation frequency or an ON duty of the switching element according to a phase-controlled AC voltage , thereby variably controlling power supplied to the discharge lamp, and supply to the discharge lamp. A lamp characteristic detection circuit for detecting that the power value is a predetermined value; and a stop circuit for generating a signal for stopping the operation of the control circuit if the predetermined value, the supply power in the all-light state is included. Means for supplying for a certain period of time, a timer circuit that operates for a certain period of time in conjunction with a switch for turning on the AC power supply, An all-light dimming command signal generating unit that generates an all-light dimming command signal for setting the dimming level to the level of the all-light state, and outputs the signal to the control circuit. A function of processing the all-light dimming command signal from the light dimming command signal generating unit in preference to a dimming command signal for variably controlling the power supplied to the discharge lamp, The discharge lamp lighting device according to claim 7, wherein the discharge lamp is supplied with electric power in an all-light state.