JP3324793B2 - High pressure discharge lamp starting device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a mercury lamp,
The present invention relates to a high-pressure discharge lamp starting device for starting and restarting a high-pressure discharge lamp such as a metal halide lamp.

[0002]

2. Description of the Related Art Generally, a high-pressure discharge lamp such as a mercury lamp or a metal halide lamp requires a high voltage as a starting voltage, and a starting device (hereinafter referred to as an igniter) for starting and restarting the high-pressure discharge lamp. The high voltage pulse generated in step (1) is applied to both ends of the lamp to start the lamp.

[0003] In particular, for instantaneous restart, although it differs depending on the type of lamp, it is generally several tens of KV.
A very high voltage is required, and a circuit as shown in FIGS. 8 and 9 (FIG. 9 is an example of the igniter I circuit in FIG. 1) is used. The operation state of this circuit will be described with reference to FIGS. Now, when the power supply Vs is turned on, a no-load secondary voltage of the ballast M is generated between a and b on the secondary side of the ballast M.

This voltage is rectified and smoothed by a diode bridge DB ₁ of an igniter I and a capacitor C ₂ .
DC voltage. Further, using the DC voltage as a power source,
Flyback transformer FBT, switching element Q ₁ ,
Diode D ₁ , capacitor C ₃ , switching element Q
On _1, the flyback converter 1 constituted by a control circuit 2 for OFF control is provided.

Furthermore, in parallel with the capacitor C _3, a primary winding n ₁ of the high-voltage pulse transformer PT and discharge gap G-
G 'is connected in series. When the switching element Q ₁ is turned on and off, as shown in FIG. 10,
The voltage V _C3 of the capacitor C ₃ gradually increases. When this voltage reaches the discharge gap G-G 'of the discharge starting voltage Vg (about several KV), the charge accumulated in the capacitor C ₃ is the primary winding n ₁ and a discharge gap G-G of the high-voltage pulse transformer PT 'Through a sudden discharge.

At this time, the high-voltage pulse transformer PT 2
The high voltage pulse Vp corresponding to the turn ratio is applied to the next winding n _2.
(For example, about several tens of KV) (see FIG. 11). The high-voltage pulse Vp is because it is applied across the lamp L via the capacitor C ₁ of the circuit of FIG. 8, the lamp L is started. At the time of restart, the operation is the same as above, and a high-voltage pulse of about several tens of KV is generated.

[0007] Incidentally, if the lamp L is started on, the on-switching elements Q _1, if stop-off operation, the voltage V _C3 of the capacitor C ₃ is raised until the discharge start voltage Vg of the discharge gap G-G ' And the generation of the high-voltage pulse stops. For simplicity of description, the igniter I of the above high pressure discharge lamp lighting device is shown in a block diagram in FIG.
It looks like 2.

Charge is gradually accumulated in the capacitor C ₄ from the DC power source 3 via the impedance Z,
The voltage V _C4 of ₄ gradually increases as shown in FIG.
This voltage V _C4 is the discharge starting voltage V of the discharge gap GG ′.
Upon reaching the g (about several KV), the charge accumulated in the capacitor C ₄ is the primary winding n ₁ of the high-voltage pulse transformer PT
And a rapid discharge occurs through the discharge gap GG ′.

At this time, the second high-voltage pulse transformer PT
The high voltage pulse Vp corresponding to the turn ratio is applied to the next winding n _2.
(For example, about several tens of KV) (see FIG. 14). The lamp L is started by the high voltage pulse Vp. The following three conditions mainly determine the ability to start and restart the lamp L within a desired time (hereinafter, referred to as starting performance) (FIG. 15).
reference).

Voltage peak value of high voltage pulse: V
_{p (peak):} Larger has better starting performance High voltage pulse width: τ: Larger has better starting performance Pulse generation interval of high voltage pulse: T: Smaller has better starting performance The above three conditions are determined according to the type and desired starting performance. The above can be varied by adjusting the discharge starting voltage Vg of the discharge gap GG ′, the turns ratio of the primary winding n ₁ and the secondary winding n ₂ of the high-voltage pulse transformer PT, and the like.

Further, the above is the capacity of the capacitor C ₄ ,
Variably by adjusting the inductance or the like of the primary winding n ₁ of the high-voltage pulse transformer PT. Further, the voltage value of the DC power supply 3, the impedance Z, can be varied by adjusting the equal volume of the capacitor C _4.

[0012]

However, the characteristics of the discharge gap GG 'used in the igniter I are different depending on the pulse generation interval T to be set. Hereinafter, this will be described. (1) When T> T _{1 When} the voltage V _C4 of the capacitor C ₄ reaches the discharge starting voltage Vg of the discharge gap GG ′, the discharge gap GG ′ becomes conductive and is stored in the capacitor C _4. charge is discharged through the primary winding n ₁ of the high-voltage pulse transformer PT.

When the discharge current becomes substantially zero, the discharge gap GG ′ becomes non-conductive. Then, electric charge in the capacitor C ₄ is accumulated again. The above operation is repeated, and T
A high voltage pulse is generated at intervals of. (2) When T ≦ T ₁ The discharge gap GG ′ becomes conductive and the capacitor C
Until the charge stored in ₄ is discharged through the primary winding n ₁ of the high-voltage pulse transformer PT, is similar to the above operation, in this condition, the discharge current is also almost 0 ,
'Remains is conductive, the impedance from the DC power source 3 Z, 1 winding n ₁ of the high-voltage pulse transformer PT, the discharge gap G-G' discharge gap G-G current continues to flow in the path of the charge in the capacitor C ₄ Is not accumulated (hereinafter, referred to as a sustained discharge phenomenon).

Therefore, only one high voltage pulse is generated, and thereafter, no high voltage pulse is generated. As described above, 'the case of using the pulse generation interval of the high-voltage pulse, the discharge gap G-G' discharge gap G-G is a restriction that can only be set to a value above T ₁ are determined for each is there.

Therefore, it is not possible to set the condition of the best pulse generation interval suitable for a lamp satisfying the starting performance. Therefore, If setting the pulse generation interval T ₁ can not be obtained the desired starting performance, the voltage peak value V of the high-voltage pulse
_{p (peak)} and the pulse width τ of the high-voltage pulse had to be increased.

[0016] When increasing the voltage peak value V _p of the high voltage pulse _(peak), it is necessary to increase the turns ratio of the primary winding n ₁ and the secondary winding n ₂ of the high-voltage pulse transformer PT. This causes a problem that the high-voltage pulse transformer PT is increased in size. Furthermore, in order to ensure insulation performance and withstand voltage performance, the insulation distance must be increased, which leads to a problem that the device becomes larger.

Further, when increasing the pulse width τ of the high voltage pulse, or to increase the capacitance of the capacitor C _4, it is necessary to increase the 1 inductance of primary winding n ₁ of the high-voltage pulse transformer PT. This has the problem that leads to upsizing of the high-voltage pulse transformer PT, a capacitor C _4. The present invention has been made in view of the above points, and an object of the present invention is to eliminate the conventional limitation on the pulse generation interval and realize the best pulse generation interval conditions suitable for a high-pressure discharge lamp satisfying the starting performance. And a high-pressure discharge lamp starting device.

[0018]

According to the present invention, a capacitor is charged from a power supply via an impedance, and a discharge starting voltage of a discharge gap connected in series with a primary winding of a high-voltage pulse transformer is set to a charging voltage of the capacitor. A high-pressure discharge lamp starting device that starts a high-pressure discharge lamp with a high-voltage pulse generated in a secondary winding of a high-voltage pulse transformer when the voltage exceeds a power supply, a plurality of primary windings and a secondary winding. A high-voltage pulse transformer having a wire, a high-pressure discharge lamp connected to a secondary winding of the high-voltage pulse transformer, a discharge gap connected in series to a plurality of primary windings of the high-voltage pulse transformer, A capacitor connected in parallel to a plurality of series circuits of a primary winding of the high-voltage pulse transformer and a discharge gap and charged from the power supply via an impedance; , The plurality of the discharge gap, its
Each pulse generation interval of high voltage pulse is sustained discharge
At intervals longer than the intervals at which
This is to discharge by imming .

Further, in the second aspect, the plurality includes
2, the plurality of the discharge gap, by respectively
The pulse generation interval of the high voltage pulse becomes a state of continuous discharge
In longer made interval than the interval is and that so as to discharge alternately.

[0020]

[Action] Thus, a plurality of discharge gaps are maintained in a state of sustained discharge.
By performing discharge at an interval longer than the interval, the discharge gap is conventionally sustained, so that a high-voltage pulse can be generated even at a high-voltage pulse generation interval that could not be set. Therefore, the best high-pressure pulse generation interval condition suitable for a high-pressure discharge lamp can be realized.

According to a second aspect of the present invention, the plural
2, the plurality of the discharge gap, by respectively
The pulse generation interval of the high voltage pulse becomes a state of continuous discharge
In longer becomes intervals than intervals, and since it is that so as to discharge alternately, conventionally, since the discharge gap resulting in sustained arc, even with high-voltage pulse generation interval could not be set, is possible to generate a high voltage pulse You can do it. Therefore, the best high-pressure pulse generation interval condition suitable for a high-pressure discharge lamp can be realized.

[0022]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows a circuit diagram of the present invention. The high-voltage pulse transformer PT includes a plurality of primary windings (a first primary winding n _1a and a second primary winding n _{1b in the} present embodiment) and one secondary winding n.
_{And two} . And the high-voltage pulse transformer P
The first primary winding n _1a of T has a first discharge gap Ga−
Ga ′ is connected to the second primary winding n _1b with the second discharge gap Gb-Gb ′ in series, forming a series circuit.

Further, the capacitor C ₅ is connected in parallel to the series circuit of the first primary winding n _1a and the first discharge gap Ga-Ga ', and the second primary winding n _1b second the discharge gap Gb-Gb series circuit of a 'and the capacitor C ₆ is connected in parallel. Then, a connection point of the capacitor C ₅ and the capacitor C _6, the first discharge gap Ga-Ga 'and the connection point of the second primary winding n _1b are connected. The two capacitors C ₅ and C ₆ are charged from the DC power supply 3 via the impedance Z.

Next, the operation of the circuit shown in FIG. 1 will be described with reference to FIGS.
3 will be described. (1) C_Five= C₆, V_ga<V_gbin the case of. (See FIG. 2)_gaIs the discharge opening of the first discharge gap Ga-Ga '.
Starting voltage, V _gbIs the second discharge gap Gb-G
b ′ is the discharge starting voltage. First, the DC power supply 3
Capacitor C via impedance Z_FiveAnd capacitor C
₆Is charged. As shown in FIG.
C_FiveCharging voltage V_C5Is the first discharge gap Ga-G
a 'discharge start voltage V_gaReaches the first discharge gap.
Ga-Ga 'conducts and the capacitor C_FiveCharge is high
First primary winding n of pulse transformer PT_1a, First discharge
Discharge occurs through the gap Ga-Ga '.

This discharge causes the high-voltage pulse transformer P
The secondary winding n ₂ T, then as shown in FIG. 2 (b), a high voltage pulse Vp is generated. When the discharge current of the capacitor C ₅ is substantially 0, the first discharge gap Ga-G
a ′ becomes non-conductive. Then, again, the DC power supply 3 charges the capacitors C ₅ and C ₆ via the impedance Z. As the charging voltage V _c6 of the capacitor C ₆ is shown in FIG. 2 (a), 'reaches the discharge starting voltage V _gb, the second discharge gap Gb-Gb' second discharge gap Gb-Gb conduction I do.

[0026] 'By conducts, the second primary winding n _1b charge high-voltage pulse transformer PT of the capacitor C _6, the second discharge gap Gb-Gb' The second discharge gap Gb-Gb the Discharge through. By this discharge, the secondary winding n ₂ of the high-voltage pulse transformer PT high voltage pulse Vp is generated as shown in FIG. 2 (b).

[0027] the discharge current of the capacitor C ₆ is substantially 0, the second discharge gap Gb-Gb 'becomes nonconductive.
The above operation is repeated. However, the discharge interval between the first discharge gap Ga-Ga 'and the second discharge gap Gb-Gb' is an interval at which no sustained discharge occurs. (2) The case where C ₅ <C ₆ and V _ga = V _gb . (See FIG. 3) Capacitor C from DC power supply 3 via impedance Z
₅ and charges the capacitor C ₆ is charged. FIG. 3 (a)
As shown in the figure, the charging voltage V _C5 of the capacitor C ₅ is the first voltage.
Discharge 'reaches the discharge starting voltage V _ga of the first discharge gap Ga-Ga' gap Ga-Ga becomes conductive, the first 1 charges the high-voltage pulse transformer PT of the capacitor C ₅
Winding n _1a, it discharges through the first discharge gap Ga-Ga '.

This discharge causes the high-voltage pulse transformer P
The secondary winding n ₂ T, then as shown in FIG. 3 (b), a high voltage pulse Vp is generated. When the discharge current of the capacitor C ₅ is substantially 0, the first discharge gap Ga-G
a ′ becomes non-conductive. Then, again, the DC power supply 3 charges the capacitors C ₅ and C ₆ via the impedance Z. As the charging voltage V _c6 of the capacitor C ₆ is shown in FIG. 3 (a), 'reaches the discharge starting voltage V _gb, the second discharge gap Gb-Gb' second discharge gap Gb-Gb conduction I do.

[0029] 'By conducts, the second primary winding n _1b charge high-voltage pulse transformer PT of the capacitor C _6, the second discharge gap Gb-Gb' The second discharge gap Gb-Gb the Discharge through. By this discharge, the secondary winding n ₂ of the high-voltage pulse transformer PT high voltage pulse Vp is generated as shown in FIG. 3 (b).

[0030] the discharge current of the capacitor C ₆ is substantially 0, the second discharge gap Gb-Gb 'becomes nonconductive.
The above operation is repeated. However, the discharge interval between the first discharge gap Ga-Ga 'and the second discharge gap Gb-Gb' is an interval at which no sustained discharge occurs. Figure 4 shows a detailed circuit diagram of the igniter I, capacitor C ₅ and as a means for charging the charge on capacitor C _6, ballast unloaded secondary voltage diode bridge DB ₁ of M shown in FIG. 8,
It is powered by a DC voltage obtained by rectifying and smoothing capacitor C _2.

Further, the flyback transformer FBT, and using a switching element Q _1, a diode D _1, the flyback converter 1 having the switching element Q ₁ on, the control circuit 2 to turn off control. (Embodiment 2) Embodiment 2 is shown in FIG. In this example,
As a means for charging an electric charge in the capacitor C ₅ and the capacitor C _6, it is obtained using AC power source V _A, the impedance Z.

FIG. 6 is a specific circuit diagram of the circuit shown in FIG. As the AC power source V _A, is to utilize through the transformer T ₁ a no-load secondary voltage of the ballast M shown in FIG. The operation, depending on the polarity of the AC power source, also changes polarity charges in the capacitor C ₅ and the capacitor C ₆ is charged. Incidentally, the entire operation is almost the same as the operation of the previous embodiment.

[0033] (Embodiment 3) FIG. 7 shows a third embodiment, the capacitor C ₅ and as a means for charging the charge on capacitor C _6, each of the capacitors C _5, C ₆ to a DC power source 3,
4. One set of impedances Z ₁ and Z ₂ is provided. The operation is the same as in the first embodiment.

In this embodiment, C ₅ = C ₆ and V _ga = V
_{As gb} , the timings of charging the capacitors C ₅ and C ₆ with electric charges are shifted, and the charging voltages V _C5 and V _c6 become V _ga (=
V _gb ) can be realized by alternately reaching V _gb ). Further, in each of the above embodiments, the case where the number of primary windings of the high-voltage pulse transformer is two has been described. However, the present invention can be applied to the case where the number is two or more. In this case, a discharge gap is connected in series with each primary winding, and a capacitor is connected in parallel with this series circuit. In addition, the discharge intervals of the plurality of discharge gaps are intervals at which no sustained discharge occurs.

[0035]

According to the present invention, as described above, a capacitor is charged from a power supply via an impedance, and the discharge starting voltage of a discharge gap connected in series with the primary winding of the high-voltage pulse transformer is determined by the charging voltage of the capacitor. Is exceeded,
A high-pressure discharge lamp starting device for starting a high-pressure discharge lamp with a high-voltage pulse generated in a secondary winding of a high-voltage pulse transformer, comprising a power supply, a high-voltage pulse transformer having a plurality of primary windings and a secondary winding. And 2 of this high-voltage pulse transformer
A high-pressure discharge lamp connected to the secondary winding, a discharge gap connected in series to the primary windings of the high-voltage pulse transformer, and a plurality of primary windings and discharge gaps of the high-voltage pulse transformer. is connection in parallel respectively to the series circuit, and a capacitor charged through the impedance from the power supply, the plurality of the discharge gap, it
The pulse generation interval of the high voltage pulse caused by the
At intervals that are longer than
In this case, the discharge gap is continuously discharged by discharging the plurality of discharge gaps at intervals longer than the interval of the continuous discharge state. The high-voltage pulse can be generated even at the high-voltage pulse generation interval that could not be set. Therefore, the present invention has an effect of providing a high-pressure discharge lamp starting device capable of realizing the best high-pressure pulse generation interval condition suitable for a high-pressure discharge lamp.

In the second aspect, the plurality is defined as
2, the plurality of the discharge gap, by respectively
The pulse generation interval of the high voltage pulse becomes a state of continuous discharge
In longer becomes intervals than intervals, and since it is that so as to discharge alternately, conventionally, since the discharge gap resulting in sustained arc, even with high-voltage pulse generation interval could not be set, is possible to generate a high voltage pulse You can do it. Accordingly, it is possible to provide a high-pressure discharge lamp starting device capable of realizing the best high-pressure pulse generation interval condition suitable for a high-pressure discharge lamp.

[Brief description of the drawings]

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

FIG. 2 is an operation explanatory diagram in the case of C ₅ = C ₆ and V _ga <V _{gb in} the above.

FIG. 3 is an explanatory diagram of an operation when C ₅ <C ₆ and V _ga = V _{gb in} the above.

FIG. 4 is a specific circuit diagram of FIG.

FIG. 5 is a circuit diagram of a second embodiment of the above.

FIG. 6 is a specific circuit diagram of FIG.

FIG. 7 is a circuit diagram of a third embodiment of the present invention.

FIG. 8 is a block circuit diagram of a conventional high pressure discharge lamp starting device.

FIG. 9 is a specific circuit diagram of an igniter part according to the third embodiment.

FIG. 10 is an operation explanatory diagram showing a charging waveform of the capacitor of the above.

FIG. 11 is an operation explanatory diagram showing a state of occurrence of a high-voltage pulse according to the first embodiment;

FIG. 12 is a circuit diagram when FIG. 9 is simplified.

FIG. 13 is an operation explanatory diagram showing a charging waveform of the capacitor of the above.

FIG. 14 is an operation explanatory diagram showing a state of occurrence of a high-voltage pulse according to the embodiment.

FIG. 15 is an explanatory diagram of the operation of the high voltage pulse of the above.

[Explanation of symbols]

1 flyback converter 2 control circuit 3 DC power supply C ₅ capacitor C ₆ capacitors PT high-voltage pulse transformer n _1a second first primary winding n _1b primary winding n ₂ 2 winding Ga-Ga 'first Discharge gap Gb-Gb 'of the second discharge gap Z impedance L lamp

Claims (2)

(57) [Claims] A capacitor is charged from a power supply via an impedance, and when a charging voltage of the capacitor exceeds a discharge starting voltage of a discharge gap connected in series with a primary winding of a high voltage pulse transformer, a high voltage pulse is generated. Transformer 2
In a high pressure discharge lamp starting device configured to start a high pressure discharge lamp by a high voltage pulse generated in a secondary winding, a power supply, a high voltage pulse transformer having a plurality of primary windings and secondary windings, A high-pressure discharge lamp connected to the secondary winding of the transformer, a discharge gap connected in series to the plurality of primary windings of the high-voltage pulse transformer, a primary winding and a discharge gap of the high-voltage pulse transformer a plurality of respectively connected in parallel to the series circuit, and a capacitor charged through the impedance from the power supply, the plurality of the discharge gap, a high voltage pulse according to each of the
Pulse generation interval is longer than the interval between sustained discharge states
A high-pressure discharge lamp starting device characterized in that discharge is performed at different intervals and at different timings . 2. The method according to claim 1, wherein the plurality is two, and the plurality of discharge gaps are respectively generated by generating a high-voltage pulse.
An interval in which the interval is longer than the interval in which a sustained discharge occurs
2. The high pressure discharge lamp starting device according to claim 1, wherein the discharge is performed alternately.