JP3315744B2 - Dimming discharge lamp lighting device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

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

[0002]

2. Description of the Related Art The afterglow of a discharge lamp can be prevented.
Dimming discharge lamp lighting devices have already been proposed (Japanese Patent Application
4-134001). This dimming discharge lamp lighting device
Is basically a low-pressure mercury lamp, as shown in FIG.
Discharge lamp 1 and high frequency power supply to this discharge lamp 1
Supply the preheating power to the high frequency power supply 2 and the discharge lamp 1
And a discharge run from the high-frequency power supply 2.
Control the power supplied to the heater 1 and
Supply of the preheating power supplied to the discharge lamp 1 from the supply unit 4
A high frequency power supply 2 and a preheating power supply.
Discharge lamp from both or either of the power supply units 4
The power supplied to the discharge lamp 1 is substantially turned off.
Power control means that can control the level of
This is the extinction time of activated ions in the discharge lamp 1.
Between 1 msec and 800 msec, high frequency power supply 2
Alternatively, the discharge lamp 1 can be turned on from the preheating power supply unit 4.
Level power is not supplied to the discharge lamp 1
The re-lighting limiting means is provided in the control unit 3. 5 is reserved
Thermal power, Z₁, Z _TwoAre impedance elements, 1
0 is the dimming signal S₁This is a dimming signal generation unit that generates

The specific operation of the dimming discharge lamp lighting device shown in FIG.
The road is shown in FIG. This dimming discharge lamp lighting device is shown in FIG.
As shown, an AC power supply AC is connected to a diode bridge DB.₁
And smoothing capacitor C_{twenty one}To rectify and smooth the DC voltage
This DC voltage is converted into a high-frequency voltage by the inverter circuit 6.
Instead, the voltage is applied to the discharge lamp 1. Here,
The barter circuit 6 is a so-called half-bridge type.
And smoothing capacitor C_{twenty one}Switches connected in series at both ends of
Switching element (MOSFET) Q₁₁, Q₁₂In the control unit 3
Turn on and off alternately, DC cut capacitor C _{twenty two}
And the choke coil L₁₁And capacitor C_{twenty three}Consists of
High frequency power is supplied to the discharge lamp 1 via the series resonance circuit
are doing. Note that the switching element Q₁₁, Q₁₂On both ends of
Is a diode D for reflux in anti-parallel._{twenty one}, D_{twenty two}Connect
is there.

[0004] via a DC cutting capacitor C ₂₂ of the inverter circuit 6 outputs is supplied to the filament of the discharge lamp 1 through the preheating transformer T _11, and to perform the preheating of the filaments. The on / off control of the switching elements Q ₁₁ and Q ₁₂ of the inverter circuit 6 is performed by the control unit 3, and the power supply for the control unit 3 is a power supply transformer T ₁₂ , a diode bridge DB ₂ , a smoothing capacitor C ₂₄
And the Zener diode consists of ZD ₁₁ control power source 7
It is created in.

In this discharge lamp lighting device, the power supplied from the inverter circuit 6 to the discharge lamp 1 is adjusted by changing the switching frequency of the inverter circuit 6 created by the control section 3, and the discharge lamp 1 is dimmed. It can be turned on. The control unit 3 includes a general-purpose switching regulator integrated circuit (for example, μPC4 manufactured by NEC Corporation).
94) Drive circuit 8 with 9 outputs (pins 8 and 11)
The transistors Q ₁₁ and Q ₁₂ of the inverter circuit 6 are alternately turned on and off via the switches a and 8b.

The driving circuits 8a and 8b are provided with switching regulators.
MOS that is turned on and off by the output of the comparator integrated circuit 9
FETQ₁₄And this MOSFET Q₁₄On and off
Transformer T that generates a secondary output by the current flowing through the primary side₁₃
And the bias resistor R₄₆, R₄₇And switching element Q
₁₁, Q₁₂Diode D to speed up turn-off _{twenty three}
And so on. Here, the switching element on the low potential side
Child Q₁₂The bias voltage applied to the
Element Q₁₁It is not necessary to raise the potential as in
Transformer T of circuit 8b₁₃Ground one end of the secondary winding of
I have.

The dimming control of the discharge lamp 1 is performed by changing the switching frequency of the switching elements Q ₁₁ and Q ₁₂ of the inverter circuit 6. In this case, by controlling the voltage of the control terminal (6th pin) of the switching regulator integrated circuit 9, the frequency changes to a rectangular wave signal output from the output terminal. Control of the control terminal of the switching regulator integrated circuit 9, the transistor Q ₁₅ of the collector current power control means as the dimming signal generating unit dimmer signal given from 10 S
_This is done by controlling according to ₁₁ . Now, when the voltage of the dimming signal S ₁₁ is high, to increase the collector current of the transistor Q ₁₅ is, the potential of the control terminal is low, the rectangular wave signal output from the output terminal frequency becomes high, the inverter circuit 6 The switching frequency of the switching elements Q ₁₁ and Q ₁₂ increases. With such switching frequency increases, the switching frequency from the resonance frequency of the series resonant circuit consisting of the choke coil L ₁₁ and the capacitor C ₂₃ is away, the power supplied to the discharge lamp 1 decreases. For this reason, the lighting state of the discharge lamp 1 becomes dark.

[0008] Conversely, when the voltage of the dimming signal S ₁₁ is lowered,
The potential of the control terminal rises, and in the opposite operation to the above,
The switching frequency of the switching elements Q ₁₁ and Q ₁₂ of the inverter circuit 6 decreases, the power supplied to the discharge lamp 1 increases, and the lighting state of the discharge lamp 1 increases.
Here, the dimming signal generating unit 10 can reduce the dimming state until the discharge lamp 1 is substantially turned off. Therefore, the turning off of the discharge lamp 1 can be detected from the potential of the control terminal. At this time, the inverter circuit 6 and the preheating transformer T
If the supply of power to the discharge lamp 1 from ₁₁ is stopped,
The discharge lamp 1 can be turned off without causing the afterglow phenomenon.

[0009]

However, in this method, since both the preheating power supply unit 4 and the high frequency power supply 2 must be stopped for a certain period of time, they cannot be turned on immediately. Further, when the high-frequency power supply 2 is restarted, there is a problem that stress is applied to the element. Accordingly, an object of the present invention is to provide a dimming discharge lamp lighting device capable of immediately lighting a discharge lamp and reducing stress associated with immediate lighting of elements constituting an inverter circuit. .

[0010]

According to a first aspect of the present invention, there is provided a dimming discharge lamp lighting device which supplies a high frequency power for lighting and preheating to a discharge lamp, and an oscillating frequency of the high frequency power source according to a dimming signal. And a fade-out unit for controlling the amount of high-frequency power supplied to the discharge lamp. The fade-out section temporarily shifts the oscillation frequency of the high-frequency power supply from the lighting frequency to the lighting frequency at which the voltage applied to the discharge lamp falls below the lighting maintenance voltage in response to the discharge lamp turn-off signal, and then immediately turns on the discharge lamp A transition is made to a standby frequency in which a preheating state is possible and the voltage applied to the discharge lamp does not reach the ignition voltage.

According to a second aspect of the present invention, there is provided a dimming discharge lamp lighting device,
2. A lighting device for a dimming discharge lamp according to claim 1, further comprising a DC power supply unit for superimposing and supplying a DC power for lighting to the discharge lamp, and supplying DC power during a period in which an oscillation frequency of the high-frequency power supply is set to an extinguishing frequency. The DC power supplied from the unit to the discharge lamp is reduced. According to a third aspect of the present invention, in the lighting device for a dimming lamp according to the second aspect, two frequencies, high and low, are set as standby frequencies in a fade-out portion, and the standby frequencies are alternately changed at regular intervals. The frequency is switched between high and low.

[0012]

According to the first aspect of the present invention, in response to the discharge lamp extinguishing signal, the fade-out portion changes the oscillation frequency of the high-frequency power supply from the operating frequency to the voltage applied to the discharge lamp below the sustaining voltage. Since the frequency is temporarily shifted to the extinguishing frequency, the discharge lamp is extinguished. After that, the fade-out section sets the discharge lamp to a preheating state in which the discharge lamp can be immediately turned on and shifts to a standby frequency at which the discharge lamp does not reach the ignition voltage. As a result, the preheating state in which the discharge lamp can be turned on immediately without being turned on continues.

According to the configuration of the second aspect of the present invention, the DC power supplied from the DC power supply unit to the discharge lamp is reduced by the DC power control unit during the period in which the oscillation frequency of the high frequency power supply is set to the extinguishing frequency. According to the configuration of the invention described in claim 3, and sea urchin by alternately switching the high and low two frequencies a waiting frequency for each predetermined time, intermittently restrict preheating power supplied to the discharge lamp.

[0014]

Embodiments of the present invention will be described below with reference to the drawings. [First Embodiment] A first embodiment of the present invention will be described with reference to FIGS. The dimming the discharge lamp lighting device, as shown in FIG. 1, the discharge lamp DL ₁ to a high frequency power supply for supplying high-frequency power for lighting and preheating (AC power source, rectifying and smoothing circuit, inverter circuit and the preheating transformer, etc.) and DN _1, and a control unit CR ₁ to increase or decrease the high-frequency power supplied by controlling the oscillation frequency of the high frequency power source DN ₁ to the discharge lamp DL ₁ according dimming signal, the fade-out portion FO
_{With one} . The fade-out section FO ₁ changes the oscillation frequency of the high-frequency power supply DN ₁ from the lighting frequency to the voltage applied to the discharge lamp DN ₁ from the lighting frequency in response to the discharge lamp extinguishing signal (obtained by narrowing the dimming signal V _sig to the minimum). temporarily shifted to off frequencies of state below the transition to a subsequent discharge lamp voltage applied to DL ₁ immediate illuminable preheat state Toshikatsu discharge lamp DL ₁ is a state of not reaching the ignition voltage standby frequency It is to let.

Control unit CR₁And fade-out section FO
₁Is the control power supply CR_TwoIt is powered by and operates. Less than,
High frequency power supply DN₁, Control power supply DN_Two, Control unit CR₁And
And fade out section FO₁About the configuration and operation of
I will tell. First, the high frequency power supply DN₁Is the AC power supply AC
Current supply voltage to four diodes D₁~ D_FourCommutation consisting of
Bridge and smoothing capacitor C₁Rectifying and smoothing with
To a DC voltage, and two switches connected in series to this DC voltage.
Switching element Q₁, Q _TwoWith the main component of
Supply to the bridge type inverter circuit,
Child Q₁, Q_TwoAre turned on and off alternately.
Discharge lamp DL from inverter circuit₁For lighting and
High-frequency power for preheating is supplied.

Switching element constituting inverter circuit
Child Q₁, Q_TwoHas a reflux diode D_Five, D₆But
Connected in anti-parallel, and the switching element Q_TwoBetween both ends of
DC cut capacitor C_ThreeThrough the choke coil
L₁And capacitor C_FourThrough a series resonant circuit
Discharge lamp DL₁Is connected. Also switch
Element Q_TwoDC cut capacitor C between both ends_ThreeTo
Preheating transformer T through ₁Primary winding is connected and the preheating
Lance T₁The two secondary windings are choke coils respectively
L_Two, L_ThreeThrough the discharge lamp DL₁Both filaments
It is connected to the.

[0017] By supplying both the filament of the discharge lamp DL ₁ through the preheating transformer T ₁ a radio frequency power obtained across the switching element Q _2, the discharge lamp DL ₁ preheated, and the switching element Q by supplying high-frequency power obtained between _two ends between both filaments of the discharge lamp DL _1, the discharge lamp DL ₁ to high frequency lighting.

The switching control of the switching elements Q ₁ and Q ₂ is performed by a control unit CR ₁ described below, and the switching frequency can be arbitrarily changed in accordance with the dimming signal. has become a lamp DL ₁ so that dimming is possible to narrow down to a minimum dimming signal, the voltage applied to the discharge lamp DL ₁ and lower than the sustaining voltage, the discharge lamp DL ₁ may be turned off It has become.

Next, the control power supply DN ₂ is connected to an AC power supply AC.
The power supply voltage is stepped down by a transformer T _2, further rectified by a rectifier bridge consisting of four diodes D ₇ to D _10, further smoothed by the capacitor C _2, the Zener diode ZD ₁
And a predetermined control power supply voltage is created.
Power is supplied to R ₁ and the fade-out section FO ₁ .

Next, the control unit CR₁Is a collection of general-purpose timers
Integrated circuit (for example, μPC5555; manufactured by NEC) IC₁
A variable frequency oscillator circuit is configured using
Switching element Q₁, Q_TwoSupply between gate and source
It has become so. Integrated circuit IC for general-purpose timer₁To
Is the resistance R₁, R_Two, R_{twenty one}, Capacitor C₆, C₉, C
₇Are connected, and their circuit constants and dimmer T
S dimming signal V_sigThe oscillation frequency f is determined by
Circuit, the dimming signal V of the dimmer TS_sigChange
For example, integrated circuit IC for general-purpose timer₁Pin 5 voltage
Change the oscillation frequency f by changing
I have to.

That is, the dimming signal V of the dimmer TS_sigChange
And integrated circuit IC for general purpose timer₁Oscillation frequency f
By changing the oscillation frequency of the inverter circuit,
Switching element Q₁, Q_TwoSwitching frequency)
And discharge lamp DL₁Dimming or turning off
I'm trying. In this circuit, the dimming signal V_sigLevel
Raise the capacitor C₇Voltage V_C7Rise and general purpose
Integrated circuit IC for timer ₁Pin 5 (control end
) Increases, and its oscillation frequency decreases. Yo
The switching frequency of the inverter circuit
Electric lamp DL₁Becomes brighter. Conversely, the dimming signal V_sigof
If the level is lowered, the switching frequency of the inverter circuit
Number rises, discharge lamp DL₁Darkens.

The output (3rd pin) of the general-purpose timer integrated circuit IC ₁ includes inverting circuits NT ₁ , NT ₂ , NT ₃ , a resistor R ₃ , a capacitor C ₁₂ , and an exclusive NOR circuit EX.
₁ , an AND circuit AN ₁ , and a NOR circuit NO ₁ are processed by a waveform processing circuit to generate two switching signals having a rest period and alternately repeating high and low. One switching signal, the resistor _{R 4, R 5, R 6} , transformer T _4, transistors Q _6, via a drive circuit composed of diodes D _11, D ₁₂ is supplied between the gate and source of the switching element Q _2, turning on and off the switching element Q _2. The other switching signals are resistors R ₇ , R ₈ , R
_9, trans T _5, the transistors Q _7, are supplied between the gate and source of the switching element Q ₁ via a driving circuit composed of diodes D _13, D _14, turning on and off the switching element Q _1. The frequency of the switching signal, by changing the adjustment to the dimming signal V _sig dimmer TS, the discharge lamp DL ₁ may dimming.

Next, the fade-out section FO₁Is dimming
Dimming signal V output from device TS_{si g}Is the resistance R₁₃, R₁₄
Threshold voltage V obtained as a divided voltage of_sch1And comparator
OP ₁To compare. Dimming signal output from dimmer TS
V_sigAs shown in FIG. 2A, the discharge lamp DL₁To
When the aperture is turned down to turn off the light, that is, the light control signal V_{si g}
Gradually lowers the dimming signal V_sigBut
Threshold voltage V_sch1At which point the comparator OP₁of
Output V_op1From the high level to the low level as shown in FIG.
Change to a level.

[0024] By inputting the transistor Q ₈ by dividing the output V _op1 of the comparator OP ₁ with resistor R _15, R _16, transistor Q in accordance with the output V _op1 of comparator OP _1
8 is turned on and off. Period of the output V _op1 high level of comparator OP _1, the transistor Q ₈ is on, the voltage V _c8 of the capacitor C ₈ is zero as shown in FIG. 2 (c), the voltage V _c8 of the capacitor C ₈ the output V _op2 of comparator OP ₂ to be compared with the resistor R _18, the threshold voltage V _sch2 obtained as the divided voltage of the R ₁₉ has a low level, as shown in Figure 2 (d).

Here, the comparator OP₁Output V_op1Compare with
Vessel OP_TwoOutput V_op2Is a diode D_Fifteen, D₁₆In
The resistance R₂₀Through Transis
TA Q _ThreeV applied to the base of_dIs shown in FIG.
High level, the transistor Q_ThreeIs on
You. As a result, the resistance R₁₂And transistor Q_ThreeConnection point
When the voltage goes low, the transistor Q_FourIs off
Capacitor C₇Voltage between both ends of_c7Fig. 2 (f)
As shown in FIG._sigAccording to the level drop of
And gradually descends. This allows the timer to be integrated
Road IC₁As shown in FIG. 2 (g), the oscillation frequency f of
Frequency f₁Until the discharge lamp DL₁
Gradually decreases.

Then, the dimming signal V_sigIs the threshold voltage V
_sch1At which point the comparator OP ₁Output V_op1Is a figure
Change from high level to low level as shown in 2 (b)
Then, the transistor Q₈Is turned off, the resistance R₁₇
Through capacitor C₈Starts charging and the capacitor C
₈Voltage between both ends of_c8Rises as shown in FIG.
At first, this voltage V_c8Is t₁Threshold voltage V after elapse of time
_sch2And the comparator OP_TwoOutput V
_op2Is a comparator OP as shown in FIG.₁Output
V_op1From the time when changed from high level to low level
t₁After a time, it changes from low level to high level.

[0027] Thus, the voltage V _d applied to the base of the transistor Q _3, as shown in FIG. 2 (e), it will be restored to a high level after a low level only t ₁ hour. As a result, the transistor Q _3, Q ₄ are once turned off, the voltage V _c7 across capacitor C ₇ in a state of ON, as shown in FIG. 2 (f), after zero, the dimming signal V _sig To the voltage determined by the level of As a result, the oscillation frequency f of the timer integrated circuit IC ₁ becomes
As shown in (g), once it shifted to the frequency f ₂ from the state of the frequency f _1, back to frequency f ₁ after a lapse of time t _1, to maintain the state of the frequency f _1.

[0028] The frequency from the oscillation frequency f is the frequency f ₁ f ₂
When you migrate to, the discharge lamp DL ₁ from the high-frequency power supply DN ₁
Will be lower than the lighting maintenance voltage,
Also reduced preheating current supplied to a discharge lamp DL ₁ through the preheating transformer T _1, the discharge lamp DL ₁ will be turned off. Then, the oscillation frequency f is the return from the frequency f ₂ to frequency f _1, the discharge lamp DL ₁ is preheated immediately lit state. At this time, the high frequency power supply DN ₁
Voltage applied to the discharge lamp DL ₁ from the discharge lamp D
Since not reach the ignition voltage of L _1, the discharge lamp DL ₁ is not able to light, it will be waiting in the preheat state.

In the above description, the oscillation frequency f is changed to the discharge lamp DL ₁ during the standby period in the preheating state.
Off and just before that in the same frequency f ₁ and need not match the same frequency f _1, the discharge lamp DL ₁ can preheated immediately illuminable state, yet discharge lamp DL ₁ frequency f ₃ which does not light up ( If equal to f ₁ may be a also). Corresponding to the lighting frequency in the range of the frequency f ₁ frequencies below claims, the frequency f ₂ corresponds to the same off frequency, the frequency f ₃ also corresponds to the standby frequency.

According to this dimming discharge lamp lighting device,
FO₁The discharge lamp extinguish signal (dimming
Signal V_sigHigh frequency power supply DN₁
The oscillation frequency of the discharge lamp DL₁Joined
To a turn-off frequency at which the power supply voltage falls below the lighting maintenance voltage.
Temporarily shift to discharge lamp DL₁And turn it off.
After the discharge lamp DL₁To a preheated state that can be turned on immediately.
And discharge lamp DL₁Will not reach the firing voltage of
Since the frequency is shifted to the standby frequency, the discharge lamp DL ₁Lights up
Without discharge lamp DL₁Preheating that can be turned on immediately
The state continues and the discharge lamp DL₁Light up instantly
To the elements that make up the inverter circuit.
It is possible to reduce the stress accompanying the instant lighting.

[Second Embodiment] A second embodiment of the present invention will be described with reference to FIGS. As shown in FIG. 3, this dimming discharge lamp lighting device includes a high frequency power supply DN ₃ instead of the high frequency power supply DN ₁ of FIG.
Used, it is used fadeout portion FO ₂ and also instead of the fade-out portion FO _1. Other configurations are the same as those of the dimming discharge lamp lighting device of FIG.

As shown in FIG. 3, the high frequency power supply DN ₃
Obtained by the supplying structure superimposed to the discharge lamp DL ₁ DC power for sustaining during low luminous flux level, transformer connecting the primary winding via a DC blocking capacitor C ₃ to the switching element Q ₂ and connected to the rectifier and smoothing circuit via the choke coil L ₄ to the secondary windings of T ₃ consists of a diode D ₁₇ and the capacitor C ₁₂ is taken to obtain a DC voltage. The portion that constitute the DC power supply unit.

The switching element Q_TwoFrom both ends of
DC cut capacitor C_TenThrough the discharge lamp DL₁
Supply high frequency power to the capacitor C₁₂High lap from both ends of
Choke coil L for wave cutting_FiveThrough the discharge lamp DL
₁DC power to the discharge lamp DL₁Preheating is preheating
Preheating capacitor C instead of transformer_FiveUsing
Like that. At this time, the discharge lamp DL₁Directly join
The current voltage is _ThreeArbitrarily set according to the turns ratio of
Can be

Fade-out section FO_TwoIs the dimming signal V
_sigIs the resistance R_Ten, R₁₁Divide the voltage with comparator OP₁Enter
Is the fade-out section FO₁Only different from that
Other configurations are the same. Here, the discharge lamp DL₁Turn off
The operation at the time of lighting will be described. Discharge lamp DL₁To
When turned off, integrated circuit IC for general-purpose timer₁Oscillation
Frequency f (high frequency power supply DN_TwoThe oscillation frequency of
(A) As shown in FIG.
L₁Is gradually darkened, and the oscillation frequency f ₁
Immediately after the frequency f_TwoSoar to

[0035] Then, the impedance of the choke coil L ₄ is increased, decreases the voltage of the smoothing capacitor C _12, the DC voltage V _DC to be superimposed to the discharge lamp DL ₁ is, as shown in FIG. 4 (b), gradually And immediately after the DC voltage _VDC changes to the voltage _VDC1 , the voltage drops to the voltage _VDC2 . At this time, the high-frequency voltage V _INV output from the inverter circuit also gradually decreases as shown in FIG. 4C, and immediately after the high-frequency voltage V _INV changes to the voltage V _INV1 , the voltage V _INV is increased. _Descend to _INV2 . A discharge lamp is DL _1, as shown in FIG. 4 (d), the voltage V _DL1 obtained by adding the high-frequency voltage V _INV and the DC voltage V _DC (= V
_INV + V _DC ).

The above-mentioned voltage V _DC1 is set lower than the lighting sustaining voltage V _X (see FIG. 4 (b)) of the discharge lamp DL ₁ , and the DC voltage V _DC and the high-frequency voltage V _{INV make the} discharge lamp D 1
L ₁ is to be able to maintain lighting. Therefore,
_{Filter the} dimming signal V _sig to reduce the DC voltage _VDC to the voltage _VDC2
When the high-frequency voltage V _INV becomes the voltage V _INV2 , the sum of the DC voltage V _DC and the high-frequency voltage V _INV becomes lower than the lighting maintenance voltage, and the discharge lamp DL ₁ can be maintained and turned off. Would.

When the time t ₁ elapses after the discharge lamp DL ₁ is turned off by narrowing down the dimming signal V _sig , the oscillation frequency f of the general-purpose timer integrated circuit IC ₁ becomes the frequency f _{1 as} shown in FIG. returned to the DC voltage V _DC is returned to voltage V _DC1 as shown in FIG. 4 (b), a high frequency voltage V _INV is also 4
The voltage V _INV1 also returns as shown in FIG.
L ₁ is turned off, the voltage V _DL1 is a DC voltage V _DC and the high frequency voltage V _INV and the sum of that time, because of the lower than the ignition voltage V _Y as shown in FIG. 4 (d), discharge lamp DL ₁ is not ignited, although the discharge lamp DL ₁ is performing preheating to maintain the off state. In FIG. 4D, V _Z indicates a lighting maintenance voltage by dimming.

[0038] According to this dimming the discharge lamp lighting device, similarly to the foregoing embodiment, the fade-out portion FO _2, in response to the discharge lamp OFF signal (narrowing of the dimming signal V _sig), the high frequency power source DN ₂ temporarily is shifted to off frequency voltage applied to the oscillation frequency from the operating frequency to the discharge lamp DL ₁ (the sum of the high frequency voltage and a DC voltage) in a state below the sustaining voltage, turns off the discharge lamp DL _1, then since it migrated to the standby frequency at which a state of not reaching the discharge lamp DL ₁ to ignition voltage of immediate illuminable preheat state Toshikatsu discharge lamp DL _1, without discharge lamp DL ₁ is turned, the discharge lamp DL ₁ continued immediately turned preheat state, with the discharge lamp DL ₁ can be immediately turned on, stress associated immediate lighting for elements constituting the inverter circuit Can be reduced.

[0039] In this embodiment, when the light control such as but DC voltage V _DC is so lowered, superimposes a discharge lamp lighting maintaining voltage following the DC voltage V _DC of DL ₁ to unlit If it is a structure, how to give it does not matter. [Third Embodiment] A third embodiment of the present invention will be described with reference to FIGS.

This dimming discharge lamp lighting device is shown in FIG.
As shown in FIG._TwoInstead of
Fade out part FO_ThreeIs used. Other configurations are
It is the same as the dimming discharge lamp lighting device of FIG. Faded
Out section FO_ThreeIs the dimming signal V_sigIs the resistance R_Ten, R₁₁In minutes
Press and resistance R₁₃, R₁₄Threshold voltage V_sch1Compare with
Vessel OP₁And the comparator OP ₁The output of the resistor R₂₇
Through the transistor Q₉Is turned on and off. Tran
Jista Q₉Is off, general-purpose timer integrated circuit IC
_TwoPin 4 goes to ground level,
Jista Q₉Is on, the control power supply voltage is₂₈,
R₂₉And the divided voltage.

The general-purpose timer integrated circuit IC ₂ is composed of the same elements as the general-purpose timer integrated circuit IC ₁ and performs an unstable oscillation operation, and outputs the dimming signal V _sig to the resistors R ₁₀ and R ₁₀ .
When the voltage divided by ₁₁ falls below the threshold voltage V _sch1 by resistors R _13, R _14, the output of the comparator OP ₁ is changed from the high level to the low level, the transistor Q ₉ is turned on, the fourth pin A voltage of 0.7 V or more is applied to the (reset terminal), and the oscillating operation starts. The general-purpose timer integrated circuit IC _2, resistors R ₂₃ to R ₂₆ and capacitors C _10, C ₁₁ is connected, the oscillation frequency is determined by these.

[0042] Then, the oscillation output from the third pin turns on and off the transistor Q ₅ is applied to the transistor Q ₅ periodically, the oscillation frequency f is also to be alternately switched to the frequency f ₁ and frequency f ₂ Become. Here, the turning off will be described in more detail. When the general-purpose timer integrated circuit IC ₂ operates by reducing the dimming signal V _sig , the general-purpose timer integrated circuit IC ₂ has resistances R ₂₅ , R ₂₅ with a duty determined by the resistors R ₂₃ and R ₂₄ and the capacitor C _11. It oscillates with a square wave with a frequency determined by ₂₆ . Therefore, the voltage V
_The level of _d also changes in a rectangular wave shape accordingly. Period of the voltage V _d high oscillation frequency f period frequency f _2, and the voltage V _d at the low level as shown in FIG. 6 (a) the oscillation frequency f is the frequency f _1. By periodic changes of the oscillation frequency f, the high frequency power supplied from the inverter circuit in the state in which a frequency f ₂ to the discharge lamp DL _1, DC power, the preheating current is limited, the discharge lamp DL ₁ lights It cannot be maintained and goes out. Then, since the integrated circuit IC ₂ for general timer that oscillates at the same period, the oscillation frequency f is that preheating the discharge lamp DL ₁ period which is the frequency f ₁ is performed. That is,
Preheating of the discharge lamp DL ₁ is to be intermittently limitations, there is the advantage that it is possible to reduce the power consumption of the lamp unlit (in preheated).

Other effects are the same as those of the embodiment shown in FIG. Incidentally, in the above embodiments, the lower the frequency, the current supplied to the discharge lamp DL ₁ has been described on the assumption that performed the slow operation increases, not limited to this, lowering the frequency, the discharge lamp Needless to say, the oscillation frequency can be controlled in the same manner as described above in the dimming discharge lamp lighting device that performs the phase advance operation in which the current supplied to the DL ₁ decreases. In this case, it is preferable to set the inverter operating frequency lower than the lighting frequency.

The inverter circuit constituting the high-frequency power supply is not limited to the one in the above-described embodiment, but may have any structure as long as the output can be controlled by changing the frequency.
In the above embodiment, the DC voltage is used for the dimming signal, but any signal may be used as long as the dimming level is uniquely determined. In addition, any configuration of preheating or DC superposition may be used as long as the amount can be adjusted by changing the oscillation frequency.

[0045]

According to the dimming discharge lamp lighting device of the present invention, the fade-out section changes the oscillation frequency of the high-frequency power supply from the lighting frequency to the voltage applied to the discharge lamp (only the high-frequency voltage) in response to the discharge lamp turn-off signal. Alternatively, the discharge lamp is turned off by temporarily shifting to a turn-off frequency at which the superimposed voltage of the high-frequency voltage and the DC voltage falls below the turn-on voltage, and then the discharge lamp is put into a preheating state in which it can be turned on immediately. Since the transition to the standby frequency at which the ignition voltage does not reach the ignition voltage is continued, the discharge lamp does not light up, the preheating state in which the discharge lamp can be immediately turned on continues, the discharge lamp can be turned on immediately, and the inverter can be turned on. It is possible to reduce stress associated with immediate lighting of elements constituting a circuit.

Further, by periodically switching the oscillation frequency to the first and second frequencies during standby, the preheating can be intermittently limited, and the consumption when the lamp is turned off (during preheating) can be reduced. The power can be reduced.

[Brief description of the drawings]

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

FIG. 2 is a time chart of each part of the dimming discharge lamp lighting device of FIG.

FIG. 3 is a circuit diagram showing a configuration of a dimming discharge lamp lighting device according to a second embodiment of the present invention.

FIG. 4 is a time chart of each part of the dimming discharge lamp lighting device of FIG. 3;

FIG. 5 is a circuit diagram showing a configuration of a dimming discharge lamp lighting device according to a third embodiment of the present invention.

FIG. 6 is a time chart of each part of the dimming discharge lamp lighting device of FIG. 5;

FIG. 7 is a block diagram showing a configuration of a conventional dimming discharge lamp lighting device.

8 is a circuit diagram showing a specific configuration of the dimming discharge lamp lighting device of FIG.

[Explanation of symbols]

DN ₁ high frequency power supply CR ₁ control unit FO ₁ fade-out unit DL ₁ discharge lamp

──────────────────────────────────────────────────続 き Continuation of the front page (72) Inventor Yasushi Kambara 1048 Oaza Kadoma, Kadoma City, Osaka Prefecture Matsushita Electric Works, Ltd. (56) References JP-A-3-112093 (JP, A) JP-A-61-221579 (JP, A) (58) Field surveyed (Int. Cl. ⁷ , DB name) H05B 41/36 H05B 41/24 H05B 41/282

Claims (3)

(57) [Claims] 1. A high-frequency power supply for supplying high-frequency power for lighting and preheating to a discharge lamp, and a control unit for controlling an oscillation frequency of the high-frequency power supply in accordance with a dimming signal to increase or decrease the high-frequency power supplied to the discharge lamp In response to the discharge lamp extinguishing signal, the oscillation frequency of the high-frequency power supply temporarily shifts from the lighting frequency to the extinguishing frequency at which the voltage applied to the discharge lamp becomes lower than the lighting maintenance voltage, and then the discharge lamp is immediately turned on. A dimming discharge lamp lighting device comprising: a fade-out portion that is set to a preheated state in which the lamp can be turned on and shifts to a standby frequency at which a voltage applied to the discharge lamp does not reach a firing voltage. 2. A DC power supply unit for superposing and supplying DC power for lighting to a discharge lamp is added, and the DC power supply unit supplies the discharge lamp to the discharge lamp during a period in which an oscillation frequency of a high frequency power supply is set to an extinguishing frequency. 2. The system according to claim 1, wherein the DC power is reduced in response to the shift to the light-off frequency.
The dimming discharge lamp lighting device as described in the above. 3. The dimming discharge lamp lighting according to claim 2, wherein two high and low frequencies are set as the standby frequency in a fade-out portion, and the standby frequency is alternately switched to the two high and low frequencies at predetermined time intervals. apparatus.