JP2002075673A - Electric discharge lamp lighting equipment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electric discharge lamp lighting equipment which can be used in common with high-voltage discharging lamps with different starting pulses, or the like. SOLUTION: The electric discharge lamp lighting equipment is equipped with a pulse generating circuit 91 generating a starting pulse which makes a electric-discharge lamp 57 turn on, and impressing the starting pulse to an electric discharge lamp 57, and a control circuit 61 by which the pulse generating circuit 91 controls the starting pulse impressed to the electric discharge lamp. The control circuit 61 impresses the starting pulse of the pulse voltage of the initial value set up beforehand to the electric discharge lamp 57. After that, it controls so that it may impress the starting pulse having higher pulse voltage than the pulse voltage of the above initial value to the electric discharge lamp 5. Furthermore, the control circuit 61 controls to shorten a pulse generating interval which generates the above starting pulse while making the above pulse voltage high.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a discharge lamp lighting device for applying a starting pulse for starting discharge of a high pressure discharge lamp.

[0002]

2. Description of the Related Art FIG. 8 is a diagram showing a conventional discharge lamp lighting circuit described in Japanese Patent Application Laid-Open No. 4-298997. FIG. 8 will be described below with reference to the text described in Japanese Patent Application Laid-Open No. 4-298997.

A rectifier circuit 1 is connected to a commercial AC power supply E. The output side of the rectifier circuit 1 is connected via a smoothing capacitor C1, a chopper field effect transistor FET, and a smoothing inductor L1. A full-bridge type inverter circuit 3 is connected.

The full-bridge type inverter circuit 3
Has four transistors Q1, Q2, Q3, and Q4 formed in a bridge shape, and a connection point between the transistors Q1 and Q2, a transistor Q3 and a transistor Q
4, the output winding P of the pulse transformer PT
A series circuit of T2 and the discharge lamp HID is connected. A circulating diode D1 is connected to the inverter circuit 3 via the inductor L1, and a drive circuit 4 is connected to the output side of the rectifier circuit 1.
Controls the transistors Q1, Q2, Q3, and Q4.

Further, a pulse control circuit 6 is provided in the rectifier circuit 1.
Is connected. In the pulse control circuit 6, a series circuit of a resistor R2 and a thyristor Th is connected between output terminals of the rectifier circuit 1 via a field effect transistor FET and an inductor L1. A resistor R3 is connected between the gate and the cathode of the thyristor Th, and a series circuit of a capacitor C6 and the input winding PT1 of the pulse transformer PT is connected between the anode and the cathode. The connection point between the transistor Q3 and the transistor Q4 and the thyristor T
h, between the gates of the resistors R4 and R5 and the capacitor C
7 and the diac Da are connected. The control circuit 6 responds to the potential at both ends of the transistor Q4 on the low potential side.

Next, the operation of the above embodiment will be described. First, the power of the commercial AC power supply E is rectified by the rectifier circuit 1, smoothed by the capacitor C1 and the inductor L1, and supplied to the inverter circuit 3. The field effect transistor FET is chopper-controlled by the chopper control circuit 2 to variably control the power to the inverter circuit 3.

In this state, a base current is supplied to the bases of the transistors Q1 and Q4, the transistors Q1 and Q4 are turned on, and a current is supplied through the paths of the transistor Q1, the pulse transformer PT, the discharge lamp HID and the transistor Q4. Then, the transistor Q1 and the transistor Q4 are turned off, a base current is supplied to the bases of the transistor Q3 and the transistor Q2, and the transistor Q3 and the transistor Q2 are turned on. The transistor Q3, the discharge lamp HID, the pulse transformer PT and A current is supplied through the path of the transistor Q2, and this operation is performed at about 400 Hz.

As shown in FIG. 9, when the transistor Q4 is off, the capacitor C is connected via the resistor R4.
When the voltage of the capacitor C7 becomes equal to or higher than a predetermined voltage, the diac Da is turned on, the thyristor Th is turned on, and the charge of the capacitor C6 is rapidly discharged through the input winding PT1 of the pulse transformer PT. As a result, a pulse voltage is generated, and the voltage is further boosted by the output winding PT2 to apply a pulse to the discharge lamp HID. As a result, the discharge lamp HID performs glow discharge, and the glow discharge is efficiently shifted to arc discharge. On the other hand, when the transistor Q4 is on, no current flows to the resistor R4 side, the capacitor C7 is not charged, the diac Da is off, the thyristor Th is kept off, and no pulse is generated in the pulse transformer PT.

After the discharge lamp HID is turned on, the voltage across the transistor Q4 also decreases as the lamp voltage decreases, so that the diac Da does not turn on, and thus the generation of pulses is reliably stopped. In this case, since the pulse control circuit 6 is connected to both ends of the transistor Q4 on the low potential side so that the voltage between both ends of the transistor Q4 responds, it is not necessary to use any special insulating means, and the configuration can be simplified. .

As described above, the configuration shown in Japanese Patent Application Laid-Open No. 4-298997 is provided with a current limiting circuit for full-wave rectifying a commercial power supply and limiting the power of a high-pressure discharge lamp supplied to a subsequent stage. A full-bridge inverter for supplying low-frequency square wave power, and a high-voltage pulse generating circuit for starting the high-pressure discharge lamp. The generation timing of the high voltage pulse is synchronized with the low frequency signal of the inverter.

[0011]

The high-pressure discharge lamp differs in the pulse voltage of the starting pulse for starting the discharge depending on the external shape, the composition of the enclosure, and the like. Therefore, conventionally, even if the rated lamp power at the time of stability is the same, a lighting device is required for each discharge lamp. Therefore, an object of the present invention is to provide a discharge lamp lighting device that can be used commonly for high-pressure discharge lamps having different pulse voltages of a starting pulse.

[0012]

A discharge lamp lighting device according to the present invention generates a starting pulse for lighting a discharge lamp,
A pulse generating circuit for applying a starting pulse to the discharge lamp; and a control circuit for controlling the starting pulse applied to the discharge lamp by the pulse generating circuit, wherein the control circuit comprises a starting pulse having a preset initial value pulse voltage. To the discharge lamp,
Then, control is performed to apply a starting pulse having a pulse voltage higher than the pulse voltage of the initial value to the discharge lamp.

[0013] The control circuit performs a control to shorten the pulse generation interval for generating the starting pulse while increasing the pulse voltage.

[0014] The control circuit performs a control to gradually increase the pulse voltage until the discharge lamp is turned on.

When the pulse voltage becomes larger than a predetermined value, the control circuit resets the starting pulse to the pulse voltage of the initial value, and applies the reset starting pulse to the discharge lamp. Until the discharge lamp is turned on, a control is repeatedly performed in which the pulse voltage of the starting pulse is gradually increased.

The control circuit is characterized in that the pulse generation interval is kept constant and the pulse voltage is gradually increased.

The pulse generation circuit includes a pulse generation drive circuit for generating the starting pulse, and a pulse height changing circuit for changing the height of the pulse voltage.

The control circuit includes a pulse generation interval control section for supplying a pulse generation circuit drive signal for generating the start pulse to the pulse generation drive circuit based on the pulse generation interval; A pulse generation voltage switching signal control unit for supplying a pulse generation voltage switching signal for switching the pulse voltage height to the pulse height changing circuit based on the interval, and setting the pulse generation interval and the pulse voltage; And a generation frequency setting unit that controls the pulse generation interval control unit and the pulse generation voltage switching signal control unit.

[0019]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiment 1 FIG. 1 is a diagram showing a high-pressure discharge lamp lighting device 100 (hereinafter, also referred to as “lighting device 100”) according to the present embodiment. Lighting device 10
0 operates by being connected to the commercial power supply 50. Lighting device 1
Reference numeral 00 includes a DC conversion circuit 54, an inverter circuit 55, a capacitor 56, a lighting detection circuit 59, a control circuit 61, and a pulse generation circuit 91. The DC conversion circuit 54 has a rectifying function and converts AC supplied from the commercial power supply 50 to DC. Further, the DC conversion circuit 54 limits the power supplied to the inverter circuit 55. Inverter circuit 55
Supplies a rectangular wave power to the discharge lamp 57. The inverter circuit 55 operates at a constant frequency, and drives the discharge lamp 57 based on the frequency. The discharge lamp 57 is, for example, a high-pressure discharge lamp such as a high-intensity discharge lamp. The lighting detection circuit 59 includes a DC conversion circuit 54 and an inverter circuit 55
It is provided between. The lighting detection circuit 59 includes the discharge lamp 5
7 is a circuit that detects that the LED 7 has been turned on, and notifies the control circuit 61 of the lighting using the lighting detection signal 58. Control circuit 6
Reference numeral 1 denotes a circuit that controls the entire lighting device 100. The control circuit 61 controls the pulse generation circuit 91 using the pulse generation voltage switching signals 51 and 52 and the pulse generation circuit drive signal 53.

The pulse generating circuit 91 is a circuit for generating a high-voltage pulse for starting the discharge lamp 57 when the power is turned on. The pulse generation circuit 91 includes a transformer 9
2, pulse generation drive circuit 81, and pulse height change circuit 83
And a capacitor 95. The pulse generation drive circuit 81 includes a thyristor 82. The pulse height changing circuit 83 includes a diode 84 and resistors 85, 86, 87
And switches 88 and 89. The transformer 92 has a primary winding 93 and a secondary winding 94. The DC generated by the DC conversion circuit 54 flows into the capacitor 95 via the diode 84 and one of the resistors 85, 86, 87, and the power is stored in the capacitor 95.

The pulse generating circuit drive signal 53 output from the control circuit 61 is applied to the gate G of the thyristor 82. When the pulse generation circuit drive signal 53 is applied to the gate G of the thyristor 82, the thyristor 82 turns on, and a current flows between the source S and the drain D. That is, when the thyristor 82 is turned on, a closed loop is formed by the capacitor 95, the thyristor 82, and the primary winding 93, and the power stored in the capacitor 95 flows through the primary winding 93. Due to the current flowing through the primary winding 93, a boosted current flows through the secondary winding 94 of the transformer 92. As a result, a pulse voltage is generated, and a high-voltage pulse is applied to the discharge lamp 57 by the closed loop of the capacitor 56, the discharge lamp 57, and the secondary winding 94. Thus, the discharge lamp 57 performs glow discharge.

By repeating the above operation, a high-voltage pulse is continuously generated by the pulse generation circuit 91, and the discharge lamp 57 is shifted from glow discharge to arc discharge. Thus, the discharge lamp 57 is turned on. The pulse generation frequency of the pulse generation circuit 91 depends on the pulse generation circuit drive signal 53.
Depends on the frequency of occurrence. That is, the control circuit 61 controls the pulse generation frequency of the pulse generation drive circuit 81 of the pulse generation circuit 91. Further, the height of the pulse voltage of the pulse generation circuit 91 is adjusted by turning on / off the switches 88 and 89 by the pulse generation voltage switching signals 51 and 52. That is, the control circuit 61 controls the current flowing through the pulse height changing circuit 83 of the pulse generation circuit 91.

Next, the control circuit 61 will be described with reference to FIG. The control circuit 61 includes a reset switch 62, an occurrence frequency setting unit 63, a pulse generation interval control unit 64, an application frequency counter 65, and a pulse generation voltage switching signal control unit 66. The control circuit 61 also includes the lighting device 1
00 has a circuit for controlling other circuits, but is not specifically illustrated here. The occurrence frequency setting unit 63 detects the start of the discharge lamp 57 and controls the pulse generation interval control unit 64 and the pulse generation voltage switching signal control unit 66 to control the pulse application. The occurrence frequency setting unit 63 includes the discharge lamp 5
When 7 lights up, the lighting detection signal 58 is input from the lighting detection circuit 59 and the start is completed. When the power is turned on, the generation frequency setting unit 63 sets the pulse generation height (V
Initial values are set for p) and the pulse generation interval (t). Next, the occurrence frequency setting unit 63 controls application of a plurality of pulse voltages, and then application of a plurality of high pulse voltages. Further, when the pulse voltage is high, the occurrence frequency setting unit 63 controls so as to shorten the pulse generation interval for supplying the pulse.

The pulse generation interval control unit 64 receives the pulse generation interval (t) from the generation frequency setting unit 63, and based on the input pulse generation interval (t), generates a pulse voltage multiple times by the pulse generation circuit drive signal 53. Is applied. The number of times of application is a predetermined number of times. The pulse generation interval control unit 64 generates a pulse according to the pulse generation circuit drive signal 53. The pulse generation voltage switching signal control unit 66, based on the instruction from the generation frequency setting unit 63,
On / off of the switches 88 and 89 is controlled by the pulse generation voltage switching signal 51 and the pulse generation voltage switching signal 52. The pulse generation voltage switching signal control unit 66 receives the pulse generation interval (t) and the pulse generation height (Vp) from the generation frequency setting unit 63, and inputs the input pulse generation interval (t) and the pulse generation height (Vp). ), The on / off of the switches 88 and 89 may be controlled by the pulse generation voltage switching signal 51 and the pulse generation voltage switching signal 52. That is, the pulse generation voltage switching signal control unit 66
Controls the pulse generation height (Vp) by the pulse generation voltage switching signal 51 and the pulse generation voltage switching signal 52.
The reset switch 62 is a switch that clears the value set in the application frequency counter 65 or resets the value to a predetermined value. The reset switch 62 can be realized by, for example, a dip switch, an on / off button, or the like.

FIG. 3 is an example showing how power is stored in the capacitor 95 over time. In this embodiment, it is assumed that the resistors 86 and 87 are the same. d1 is when both switches 88 and 89 are on, d2 is when only switch 88 (or switch 89) is on, and d3 is
This is the case where both the switches 88 and 89 are off. The pulse generation voltage switching signal control unit 66 includes the switch 8
8, 89 are adjusted on / off by a pulse generation voltage switching signal 51 and a pulse generation voltage switching signal 52, respectively. t1, t2, and t3 indicate pulse generation intervals, respectively, and Vc1, Vc2, and Vc3 indicate t1, t2, and t, respectively.
3 shows a capacitor voltage corresponding to 3.

FIG. 4 shows that the pulse generation circuit 91
FIG. 5 is a diagram showing a temporal change in a pulse generation height or the like applied to the substrate. “Pulse generation height” and “pulse voltage” mean the same thing. FIG. 4 shows a signal waveform in which electric power is stored in the capacitor 95 and a generation timing of the pulse generation circuit drive signal 53. Also, the pulse generation height (Vp) of the high-voltage pulse applied to the discharge lamp 57 by the pulse generation circuit drive signal 53 is shown.

In the example of FIG. 4, the pulse generation height (Vp)
Satisfies Vp1 <Vp2 <Vp3, and the pulse generation interval (t) indicates the case where t1>t2> t3. Further, the intermittent interval F ₁ between the pulse train A ₁ and the pulse train B ₁
When the intermittent interval G ₁ between the pulse train B ₁ pulse train C ₁
Is an arbitrary time, and may be the same time or different times. T1 in FIG.
Vc corresponding to t1 in FIG. 3 and associated with t1 in FIG.
When the capacitor voltage is 1, the pulse generation circuit drive signal 5
3 is output from the pulse generation interval control unit 64, and a pulse having a pulse generation height Vp 1 is applied to the discharge lamp 57 from the pulse generation drive circuit 81. Similarly, at t2, the pulse generation height Vp2 when the capacitor voltage is Vc2, and at t3, V
A pulse having a pulse generation height Vp3 at the capacitor voltage of c3 is applied to the discharge lamp 57. Thus, the capacitor voltage (Vc) is proportional to the pulse generation height (Vp).

The pulse train A ₁ is a case where both the switches 88 and 89 are off. The electric power is stored in the capacitor 95 as shown by d3 in FIG. Pulse train A _1, the pulse generation interval (t) matches the t1 in FIG. 3, pulse generator height (V
3 shows a pulse train when p) is Vp1 corresponding to Vc1 in FIG. The pulse train B1 is a case where _one of the switch 88 and the switch 89 is on. The power is stored in the capacitor 95 as shown by d2 in FIG. Pulse train B ₁ represents a pulse generation interval (t) matches the t2 in FIG. 3, pulse generator height (Vp) of FIG. 3 V
A pulse train in the case of Vp2 corresponding to c2 is shown. Pulse train C ₁ is a case which is turning on both switches 88 and 89. The power is transferred to the capacitor 95 in FIG.
Is accumulated as in d1. Pulse train C _1, the pulse generation interval (t) matches the t3 in FIG. 3, pulse generator height (Vp) indicates a pulse train when it is Vp3 corresponding to Vc3 of FIG. In FIG. 4, 3 of pulse trains A to C
Although one pulse train is illustrated, there may be another pulse train. As shown as an example in FIG. 4, this lighting device starts the discharge lamp 57 by gradually increasing the pulse generation height (Vp) and shortening the pulse generation interval (t).

Next, the operation will be described with reference to FIG. The counter stored in the application frequency counter 65 is n, the pulse generation height (pulse voltage) is Vp, and the pulse generation interval is t. When the power is turned on, the occurrence frequency setting unit 63 sets n,
Initial values are set to Vp, t, and m (S1). n is a counter, and m indicates the maximum value of the counter n. The default value is
This is a predetermined value. In the example of FIG. 4, n = 1 and Vp = V
p1, t = t1. n is stored in the pulse generation voltage switching signal control unit 66. The occurrence frequency setting unit 63 outputs t to the pulse generation interval control unit 64. Further, the occurrence frequency setting unit 63 instructs the pulse generation voltage switching signal control unit 66 on a switch to be turned on based on t and Vp. The pulse generation voltage switching signal control unit 66 includes the generation frequency setting unit 6
3, a pulse generation voltage switching signal 5
1. Switch 8 by pulse generation voltage switching signal 52
8, 89 are turned on / off to control the power stored in the capacitor 95.

The pulse generation interval control section 64 applies a predetermined number of pulses at intervals of t based on the control of the generation frequency setting section 63 (S2). When the occurrence frequency setting unit 63 detects that the lighting detection signal 58 is input from the lighting detection circuit 59 (Yes in S3), the start is completed. The occurrence frequency setting unit 63 controls the lighting detection circuit 5 by applying the pulse of S2.
9 when the lighting detection signal 58 is not input (S3
No), t and Vp for the next pulse application are set (S
4, S5). When the counter n is smaller than the maximum value m (No in S4), the occurrence frequency setting unit 63 counts up the counter n, shortens t, and increases Vp. For example,
When n = 2, t = t2 and Vp = Vp2. Also,
When n = 3, t = t3 and Vp = Vp3. The pulse generation voltage switching signal control unit 66 sets the switches 88 and 89 based on the control of the generation frequency setting unit 63. On the other hand, when the counter n is equal to or larger than the maximum value m (Yes in S4), the occurrence frequency setting unit 63 sets the respective initial values to the counters n, t, and Vp.

Next, the pulse generation interval control section 64 applies a predetermined number of pulses at intervals of t based on the control of the generation frequency setting section 63 (S2). The occurrence frequency setting unit 63
The above operation is repeated until the start of the high pressure discharge lamp is confirmed (Yes in S3). In the example of FIG. 4, the pulse train A ₁ has a counter n = 1 (initial value), and the pulse train B ₁ has a counter n
= 2, pulse train C ₁ indicates the pulse generation height when the counter n = 3. Also, the predetermined number of times of pulse application (S2) is set to five times.

As described above, when the starting device for generating a plurality of pulses generates a low pulse voltage after the power is turned on and the lamp does not light, the pulse voltage is increased and the generation interval of the starting pulse is increased. Make it shorter when the voltage is high.

In the examples of FIGS. 3 and 4, the pulse generation height (V
To change p), the pulse generation interval (t) and the switch 8
A case where both on / off of 8, 89 are added is shown. However, it is also possible to change the pulse generation height (Vp) by changing only the pulse generation interval (t),
It is also possible to change the pulse generation height (Vp) only by changing ON / OFF of the switches 88 and 89.

As described above, the high-pressure discharge lamp lighting device according to the present invention uses the DC voltage generated by the DC conversion circuit 54 via the inverter circuit 55 to discharge the load (high-pressure discharge lamp).
A pulse generating circuit 91 for supplying AC power to the discharge lamp 57 and applying a starting pulse to the discharge lamp 57;
A control circuit 61 for controlling this generated pulse, wherein the control circuit 61 applies a plurality of relatively low pulse voltages when the discharge lamp 57 is started, and thereafter applies a plurality of high pulse voltages, The pulse supply interval is shortened when the pulse voltage is high.

Further, the high pressure discharge lamp lighting device according to the present invention is characterized in that the pulse voltage is gradually increased.

Further, the high pressure discharge lamp lighting device according to the present invention is characterized in that when the high pressure discharge lamp does not discharge in a state where the pulse voltage is the highest, the operation is repeated again from the generation of the lowest pulse voltage.

Embodiment 2 In this embodiment, a case will be described in which the pulse generation interval is fixed and the pulse generation height is gradually increased to start the high pressure discharge lamp. FIG. 6 shows the pulse generation interval of this embodiment, t5 and the capacitor voltage,
Vc4 to Vc6 are plotted on a graph similar to FIG. d1 to d3 are the same as in FIG.

FIG. 7 shows a temporal change in the pulse voltage height and the like when the high piezoelectric lamp is started by gradually increasing the pulse generation height (Vp) while keeping the pulse generation interval (t) constant. Things. The pulse generation height (Vp) corresponds to Vp1 to Vp3 corresponding to the capacitor voltages Vc1 to Vc3, respectively.
Is shown. The occurrence frequency setting unit 63 outputs the pulse train A ₂ ,
The pulse generation intervals of the pulse train B ₂ and the pulse train C ₂ are the same (the value of t5). The generation frequency setting unit 63 sends the pulse generation voltage switching signal 5 to the pulse height changing circuit 83 by the pulse generation voltage switching signal control unit 66 so that power is accumulated in the capacitor 95 at the same pulse generation interval.
1. Output the pulse generation voltage switching signal 52 to adjust the pulse voltage. FIG. 7 also shows a case where one pulse application applies five pulses, but this is an example.

Embodiment 3 In FIG. 1, the pulse height changing circuit 83 includes three resistors 85 to 87 and 88 and 89.
Although the example in which the two switches are provided is shown, the invention is not limited to this. A combination of a resistor and a switch may be added to the example of FIG. The pulse generation voltage switching signal control unit 66 includes a pulse generation voltage switching signal 51,
In addition to the pulse generation voltage switching signal 52, a pulse generation voltage switching signal 51 corresponding to the added combination of the resistor and the switch may be added to adjust ON / OFF of the added switch. Further, another configuration may be used as long as the pulse generation voltage switching signal control unit 66 can control the pulse voltage by the pulse generation voltage switching signal 51.

In FIG. 4, three pulse trains A₁ ~ C
₁ Is an example, and the discharge lamp 57 is started.
Up to a maximum m pulse train can be generated. Also, the maximum value
m, if the discharge lamp 57 does not start,
The degree setting unit 63 outputs the pulse train A ₁ Pulse using the pulse
Is controlled so that the pulse generation height (V
p) is to be increased.

FIG. 4 shows an example in which a pulse of the same Vp and the same t is applied five times, but the present invention is not limited to this. The number of times of application is a predetermined number of times. Further, the application method may be the following combination. For example, a description will be given using pulse trains A ₁ , B ₁ , C ₁ and intermittent intervals F ₁ , G ₁ , H ₁ in FIG. H ₁ is not specified in FIG. 4, C ₁
The intermittent interval after. A ₁ + F ₁ means that F ₁ elapses after the pulse train A ₁ is generated. (A ₁
+ F ₁ ) 50 times and then (B ₁ + G ₁ )
Times, then (C ₁ + H ₁ ) 50 times, and so on. Other combinations may be used.

Further, the resistors provided in the pulse height changing circuit 83 may have the same electric resistance or different electric resistances.

[0043]

The high pressure discharge lamp lighting device according to the present invention comprises:
A lamp with a relatively low starting voltage is given an opportunity to start discharging with a low pulse voltage, and a lamp with a high starting voltage can be applied with a high pulse voltage and a pulse voltage with a short generation interval.

Further, the high pressure discharge lamp lighting device according to the present invention ensures the start of discharge of the high pressure discharge lamp by changing the pulse voltage height and the pulse generation interval to apply a pulse, thereby enabling different types of discharge lamps. It is also possible to provide a lighting device that can be shared by both.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating an example of a configuration of a lighting device according to the present invention.

FIG. 2 is a diagram illustrating an example of a configuration of a control circuit.

FIG. 3 is a diagram showing an example of a state in which power is stored in a capacitor according to the first embodiment over time.

FIG. 4 is a diagram showing a temporal change such as a pulse generation height applied to a discharge lamp by the pulse generation circuit of the first embodiment.

FIG. 5 is a flowchart showing an example of the operation of the control circuit.

FIG. 6 is a diagram showing an example of a state in which power is stored in a capacitor according to Embodiment 2 over time.

FIG. 7 is a diagram showing a temporal change such as a pulse generation height applied to a discharge lamp by the pulse generation circuit according to the second embodiment.

FIG. 8 is a diagram showing a conventional discharge lamp lighting device.

FIG. 9 is a waveform diagram showing a conventional pulse generation state.

[Explanation of symbols]

50 commercial power supply, 51, 52 pulse generation voltage switching signal, 53 pulse generation circuit drive signal, 54 DC conversion circuit, 55 inverter circuit, 56 capacitor, 57
Discharge lamp (high pressure discharge lamp), 58 lighting detection signal, 59 lighting detection circuit, 61 control circuit, 62 reset switch,
63 generation frequency setting unit, 64 pulse generation interval control unit,
65 application frequency counter, 66 pulse generation voltage switching signal control section, 81 pulse generation drive circuit, 82 thyristor, 83 pulse height change circuit, 84 diode, 8
5,86,87 resistance, 88,89 switch, 91
Pulse generation circuit, 92 transformer, 93 primary winding, 9
4 Secondary winding, 95 capacitor, 98 field effect transistor, 100 lighting device.

 ────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Hiroyoshi Yamazaki 2-8-29 Kitako, Nishi-ku, Yokohama-shi, Kanagawa F-term in Mitsubishi Electric OSRAM Co., Ltd. (Reference) 3K072 AA11 AB09 BA05 DD07 GA01 GA02 GB01 GB18 3K083 AA91 AA94 BA04 BA25 BA26 BC15 BC33 BC47 BD25 BE17 CA32

Claims (7)

[Claims] A pulse generating circuit for generating a starting pulse for lighting a discharge lamp and applying the starting pulse to the discharge lamp; and a control circuit for controlling the starting pulse applied to the discharge lamp by the pulse generating circuit. The control circuit performs a control of applying a starting pulse having a preset initial value pulse voltage to the discharge lamp, and thereafter applying a starting pulse having a pulse voltage higher than the initial value pulse voltage to the discharge lamp. Discharge lamp lighting device characterized by the above-mentioned. 2. The discharge lamp lighting device according to claim 1, wherein the control circuit performs control to shorten the pulse generation interval for generating the starting pulse while increasing the pulse voltage. 3. The discharge lamp lighting device according to claim 1, wherein the control circuit performs control to gradually increase the pulse voltage until the discharge lamp is turned on. 4. The control circuit resets the starting pulse to a pulse voltage of the initial value when the pulse voltage becomes larger than a predetermined value, and sends the reset starting pulse to the discharge lamp. The discharge lamp lighting device according to any one of claims 1 to 3, wherein control is performed such that the pulse voltage of the starting pulse is gradually increased until the discharge lamp is turned on. 5. The discharge lamp lighting device according to claim 1, wherein the control circuit controls the pulse generation interval to be constant and gradually increases the pulse voltage. 6. The pulse generation circuit according to claim 1, wherein the pulse generation circuit includes a pulse generation drive circuit that generates the starting pulse, and a pulse height change circuit that changes the height of the pulse voltage. Discharge lamp lighting device. 7. A pulse generation interval control section for supplying a pulse generation circuit drive signal for generating the start pulse to the pulse generation drive circuit based on the pulse generation interval, the control circuit includes: A pulse generation voltage switching signal control unit that supplies a pulse generation voltage switching signal for switching the pulse voltage height to the pulse height changing circuit based on the pulse generation interval, and the pulse generation interval and the pulse voltage. 7. The discharge lamp lighting device according to claim 6, further comprising an occurrence frequency setting unit that sets and controls the pulse generation interval control unit and the pulse generation voltage switching signal control unit.