JP5321411B2 - High pressure discharge lamp lighting device and light source device - Google Patents

Description

  The present invention relates to an improvement of a high pressure discharge lamp lighting device for lighting a high pressure discharge lamp, and more particularly to an improvement of a starting circuit for the high pressure discharge lamp.

FIG. 7 shows a circuit configuration diagram of a conventional high pressure discharge lamp lighting device. The high pressure discharge lamp lighting device (hereinafter referred to as “lighting device”) includes a DC power supply unit 20, a full bridge circuit 30, and an igniter circuit 70 (for example, FIG. 4 of Patent Document 1).
In the full bridge circuit 30, the transistors 31 and 34 and the transistors 32 and 33 are controlled so as to be alternately turned on and off at a predetermined frequency by the bridge control circuit 37, whereby the DC output from the DC power supply unit 20 is changed to AC. It is converted into a rectangular wave output and supplied to a high-pressure discharge lamp 50 (hereinafter referred to as “lamp”). Hereinafter, the configuration and operation will be described specifically for the operation at the time of starting the lamp.

  In the igniter circuit 70, the AC output voltage of the full bridge circuit 30 is first amplified twice by a voltage doubler circuit composed of diodes 71 and 74, resistors 72 and 75, and capacitors 73 and 76. That is, when the output voltage of the DC power supply unit 20 is V1, and the potential at the connection point between the transistors 33 and 34 is 0, when the transistors 31 and 34 are on and the transistors 32 and 33 are off, the full bridge circuit 30 When the output is charged to the capacitor 73 via the diode 71, while the transistors 31 and 34 are off and the transistors 32 and 33 are on, the output of the full bridge circuit 30 is charged to the capacitor 76 via the diode 74. As a result, + V1 is stored in the capacitor 73 and -V1 is stored in the capacitor 76. When the potential difference 2 × V1 exceeds the characteristic value Vs of the discharge gap 77, the discharge gap 77 breaks down and becomes conductive. This Vs is applied to the primary winding of the pulse transformer 78, and the high voltage pulse amplified on the secondary winding side is superimposed on the output voltage of the full bridge circuit 30 and applied to the lamp 50.

  As a result, a pulse voltage several tens of times higher than the output voltage of the full bridge circuit 30 (that is, the output voltage of the DC power supply unit 20) can be applied to the lamp 50.

  As for the lamp 50, as shown in FIG. 2, recently, a lamp 50 provided with a trigger wire 51 as an auxiliary conductor has been widespread in order to improve the startability of the lamp. One end of the trigger wire 51 is electrically connected to the electrode A, and the other end is wound around the electrode B. When the electrode A has a positive polarity and the electrode B has a negative polarity, startability is improved by the action of inducing the emission of electrons from the electrode B by the trigger wire 51 which is a positive electrode.

JP 2006-302550 A

By the way, in the lamp having the trigger line 51 as shown in FIG. 2, it is assumed that the pulse voltage is applied with the electrode A as the positive electrode and the electrode B as the negative electrode because the electrons are negative charges.
On the other hand, the lighting device as shown in FIG. 7 does not assume that a pulse voltage is output with a specific polarity. That is, when the discharge gap 77 is conducted with the transistors 31 and 34 turned on, a pulse is applied with the electrode A being the positive electrode, and the voltage VL of the electrode A viewed from the electrode B is as shown in FIG. As shown in (a), a large pulse voltage is obtained on the positive side. On the other hand, when the discharge gap 77 is conducted while the transistors 32 and 33 are on, a pulse is applied with the electrode A being a negative electrode, and the voltage VL is a rectangular wave as shown in FIG. A large pulse voltage is superimposed on the positive side with respect to the negative side cycle. For convenience of explanation, the pulse is drawn with a straight line in FIG. 3 (a), but when the pulse portion is enlarged, an attenuation waveform as shown in FIG. 3 (b) is obtained.

In this way, the trigger line 51 works effectively in the case of FIG. 3A, but the probability of becoming as shown in FIG. 3A depends on the start operation of the full bridge circuit 30 and the charge states of the capacitors 73 and 76. And about 50%.
Therefore, when starting the lamp 50 having the trigger wire 51, it is necessary to reliably apply a pulse voltage with a fixed polarity as shown in FIG.

  Here, if a semiconductor switching element is used instead of the discharge gap 77 and the semiconductor switching element is turned on at a desired timing, pulses can be superimposed at a specific timing (polarity). However, since the resistance value of the semiconductor switching element decreases with time during the transition from the non-conducting state to the conducting state, the discharge current of the capacitors 73 and 76 is consumed by this resistance component (especially when the resistance starts high). As a result, a sufficient voltage cannot be generated in the primary winding of the transformer 78. In addition, since a control circuit for controlling the semiconductor switching element is required, the number of parts is increased and the cost is increased.

  Accordingly, the present invention provides a fixed polarity pulse voltage using a voltage twice as high as the output of an AC output circuit (for example, a full full bridge circuit) without using a semiconductor switching element in an igniter circuit of a high pressure discharge lamp lighting device. An object of the present invention is to provide a configuration for applying a voltage to a lamp.

  A first aspect of the present invention is a high pressure discharge lamp lighting device, an AC output circuit (30) for outputting an AC voltage between a first line (L1) and a second line (L2), and an AC voltage And an igniter circuit (40) for applying a pulse voltage to the high pressure discharge lamp from the hot side output terminal (Th) and the reference output terminal (Tc), and the second line is connected to the reference output terminal. Includes a first capacitor (43) connected to the second line, a first resistor (42) connected between the first capacitor and the first line, and a second capacitor connected to the second line. Two capacitors (46), a diode (44) connected between the second capacitor and the first line with the cathode as the first line, and a point (430) on the first resistor side of the first capacitor ) And the point on the diode side of the second capacitor 460), and a transformer (primary winding connected in series with the discharge gap) and a secondary winding connected between the first line and the hot output terminal (47). 48).

  The second aspect of the present invention is a high pressure discharge lamp lighting device, an AC output circuit (30) for outputting an AC voltage between the first line (L1) and the second line (L2), and an AC voltage. And an igniter circuit (40) for applying a pulse voltage to the high pressure discharge lamp from the hot side output terminal (Th) and the reference output terminal (Tc), and the second line is connected to the reference output terminal. Includes a first capacitor (43) connected to the first line, a first resistor (42) connected between the first capacitor and the second line, and a first capacitor connected to the first line. Two capacitors (46), a diode (44) connected between the second capacitor and the second line with the cathode on the first line side, a point (430) on the first resistance side of the first capacitor ) And the point on the diode side of the second capacitor 460), and a transformer (primary winding connected in series with the discharge gap) and a secondary winding connected between the first line and the hot output terminal (47). 48).

  The third aspect of the present invention is the above-described high-pressure discharge lamp lighting device (61), the first electrode (A) connected to the hot side output end, and the second electrode (B) connected to the reference output end. A high pressure discharge lamp (50) having a reflector, a reflector (55) to which the high pressure discharge lamp is attached, and a high pressure discharge lighting device and a housing (62) containing the reflector. The light source device includes a wire (51), and one end of the auxiliary winding is electrically connected to the first electrode and the other end is wound around the second electrode.

It is a figure which shows the high pressure discharge lamp lighting device of the 1st Example of this invention. It is a figure explaining the structure of a high pressure discharge lamp. It is a figure explaining the output waveform of an igniter circuit. It is a figure explaining the output waveform of an igniter circuit. It is a figure explaining the output waveform of an igniter circuit. It is a figure explaining the modification of this invention. It is a figure which shows the high pressure discharge lamp lighting device of the 2nd Example of this invention. It is a figure which shows the light source device of this invention. It is a figure which shows the conventional high pressure discharge lamp lighting device.

Example 1.
FIG. 1 is a diagram showing a high pressure discharge lamp lighting device (hereinafter referred to as “lighting device”) according to a first embodiment of the present invention. The lighting device includes a DC power supply unit 20, a full bridge circuit 30 as an AC output circuit that converts a DC input from the DC power supply unit 20 into an AC output, and an igniter circuit 40. Note that the DC power supply unit 20 may be included in the lighting device, or may not be included in the lighting device when DC power is supplied from the outside of the lighting device.
For the sake of clarity, the output line of the full bridge circuit 30 is a line L1 on the side to which the connection point between the transistor 31 and the transistor 32 belongs, and the line L2 on the side to which the connection point between the transistor 33 and the transistor 34 belongs. And In the present embodiment, regarding the output end of the lighting device, the side to which the electrode A of the lamp 50 is connected is referred to as a hot output end Th, and the side to which the electrode B is connected is referred to as a reference (cold side) output end Tc. In the present embodiment, a reference output end Tc is provided on the line L2 side.

  The lighting device of FIG. 1 differs from the conventional example shown in FIG. 7 in the igniter circuit. The igniter circuit 40 includes a capacitor 43 connected to the line L2, a resistor 42 connected between the capacitor 43 and the line L1, a capacitor 46 connected to the line L2, and a cathode between the capacitor 46 and the line L1 on the line L1 side. The diode 44 connected in this manner, the discharge gap 47 connected between the point 430 on the resistor 42 side of the capacitor 43 and the point 460 on the diode 44 side of the capacitor 46, and the primary winding are connected in series to the discharge gap 47. The secondary winding includes a pulse transformer 48 connected between the line L1 and the hot-side output terminal Th. Further, as will be described later, a resistor 45 is connected in series with a capacitor 46 as necessary.

The operation of the igniter circuit 40 will be described using L2 as a reference potential.
When the line L1 first becomes a high potential (+ V1), the voltage of the line L1 is charged in the capacitor 43, and the potential of the point 430 becomes + V1. On the other hand, no current flows on the capacitor 46 side, and the potential at the point 460 remains zero.
Next, when the line L1 is inverted to a low potential (−V1), the capacitor 43 is discharged, and the potential at the point 430 becomes −V1. On the other hand, a current flows from the line L2 to the line L1 through the capacitor 46, the resistor 45, and the diode 44, and the potential at the point 460 becomes −V1.
Next, when the line L1 is inverted again to the high potential (+ V1), the voltage of the line L1 is charged in the capacitor 43 again, and the potential of the point 430 becomes + V1. On the other hand, no current flows on the capacitor 46 side, and the potential at the point 460 does not change from -V1.
Here, the potential difference between the points 430 and 460 becomes 2 × V1 (> discharge gap characteristic value Vs), and the discharge gap 47 breaks down and becomes conductive.

On the contrary, when the line L1 first becomes a low potential (−V1), the potentials at the points 430 and 460 become −V1 due to the current flowing from the line L2 through the capacitors 43 and 46 to the line L1. .
Next, when the line L1 is inverted to a high potential (+ V1), the voltage of the line L1 is charged in the capacitor 43, and the potential of the point 430 becomes + V1. On the other hand, no current flows on the capacitor 46 side, and the potential at the point 460 does not change from -V1.
Here, the potential difference between the points 430 and 460 becomes 2 × V1, and the discharge gap 47 breaks down and becomes conductive.

  Therefore, regardless of whether the output line L1 of the full bridge circuit 30 starts from a high potential or a low potential, the discharge gap 47 is always conducted when the line L1 is at a high potential.

  When the discharge gap 47 is conducted, current flows from the point 430 to the point 460 through the primary winding of the pulse transformer 48. In response to this current, a pulse voltage corresponding to the turn ratio is generated on the secondary winding side of the pulse transformer 48, and the pulse voltage is superimposed on the voltage (+ V1) of the line L1. As a result, the voltage waveform shown in FIG. 3A is obtained as the voltage VL. That is, the pulse voltage is superimposed when the electrode A side is a positive electrode.

  It is desirable to determine the winding direction of the secondary winding in consideration of the current direction of the primary winding of the pulse transformer 48. That is, it is desirable to determine the winding directions of the primary winding and the secondary winding so that the voltage of the line L1 when the pulse voltage is superimposed and the first half cycle of the pulse voltage have the same polarity. By doing so, as shown in FIG. 3B, the highest first half cycle of the pulse voltage is superimposed on the positive side. If this winding direction is reversed, the second highest second cycle is superimposed on the positive side. In this embodiment, the primary winding and the secondary winding are wound so as to have opposite polarities.

  The resistors 42 and 45 are connected to suppress the inrush current to the capacitor 43 and adjust the charging speed of the capacitor 43. The resistor 42 increases the impedance between the line L1 and the capacitor 43 so that the charging / discharging operation of the capacitor 43 is not affected by the operation of the full bridge circuit 30.

Further, it is desirable that the remaining period of the rectangular wave (H in FIG. 3A) continues for a long time after the pulse voltage is applied. This is because the arc growth after the dielectric breakdown by the pulse can be ensured.
Therefore, as shown in FIG. 4, the period T + in which the line L1 side of the output of the full bridge circuit 30 is at a high potential only at the start is set longer than the opposite period T− to ensure the period H longer. Also good. Even in this case, if the period T- is longer than the charging time of the capacitors 43 and 46, the change in the charging voltage of the capacitors 43 and 46 is the same as in FIG.

  Thus, according to the present invention, in the igniter circuit for starting the lamp having the trigger line, as shown in FIG. 3A by using twice the voltage of the full bridge circuit 30 with a small number of parts and a simple configuration. A configuration in which a pulse voltage with a fixed polarity is applied to the lamp can be achieved.

Example 2
FIG. 5 shows a second embodiment of the present invention. The igniter circuit is different from the first embodiment. The igniter circuit 40 'includes a capacitor 43 connected to the line L1, a resistor 42 connected between the capacitor 43 and the line L2, a capacitor 46 connected to the line L1, and a cathode connected between the capacitor 46 and the line L2. The diode 44 connected to the side, the discharge gap 47 connected between the point 430 on the resistor 42 side of the capacitor 43 and the point 460 on the diode 44 side of the capacitor 46, and the primary winding in series with the discharge gap 47 A pulse transformer 48 is connected and the secondary winding is connected between the line L1 and the hot-side output terminal Th. Further, a resistor may be connected in series with the capacitor 46 as necessary.

As in the first embodiment, the operation of the igniter circuit 40 'will be described using the line L2 as a reference potential. The potential of the point 430 is always 0 except for the transition period when the potential of the line L1 is inverted.
When the line L1 first becomes a high potential (+ V1), no current flows through the capacitor 46, so the potential at the point 460 becomes + V1 which is the same as that of the line L1.
Next, when the line L1 is inverted to a low potential (−V1), a current flows from the line L2 through the diode 44 and the capacitor 46 to the line L1, and the potential at the point 460 becomes zero.
Next, when the line L1 is inverted again to the high potential (+ V1) (that is, when the potential is increased by 2V1), the potential at the point 460 is shifted to + 2V1, and the potential difference from the point 430 is 2 × V1 (> discharge gap characteristic value Vs). ), And the discharge gap 47 breaks down and becomes conductive.

On the contrary, when the line L1 first becomes a low potential (−V1), a current flows from the line L2 to the line L1 through the diode 44 and the capacitor 46, and the potential at the point 460 becomes zero.
Next, when the line L1 is inverted to a high potential (+ V1) (that is, when the potential rises by 2V1), no current flows through the capacitor 46, so the potential at the point 460 is shifted to + 2V1. As a result, the potential difference from the point 430 becomes 2 × V1, and the discharge gap 47 breaks down and becomes conductive.

Therefore, in this embodiment as well, regardless of whether the line L1 of the full bridge circuit 30 starts from a high potential or a low potential, the discharge gap 47 is always conducted when the line L1 is at a high potential.
The operation after the discharge gap 47 is conducted is the same as that in the first embodiment.

Example 3
FIG. 6 shows a light source device (projector) as an application using the above-described high-pressure discharge lamp lighting device. In FIG. 6, 61 is the lighting device described above, and 62 is a housing in which the lighting device 61 and the lamp 50 are built. In addition, the figure is a schematic illustration of the embodiment, and the dimensions, arrangement, and the like are not as illustrated. Then, a projector is configured by appropriately arranging a video system member or the like (not shown) in the housing 62. Thereby, a projector with good startability can be obtained.

In the above, the most preferable example is shown, but the present invention can be modified as follows without departing from the gist thereof.
(1) The combination of the direction of the diode 44, the insertion position of the pulse transformer 48, the direction of the hot-side output terminal Th, and the direction of the trigger line shown in FIG. 1 or FIG. 5 is merely an example of a possible combination. For example, if the direction of the diode 44 is reversed in FIG. 1 and the positions of the hot-side output terminal (electrode A) and the reference-side output terminal (electrode B) are reversed, the pulse voltage is also changed when the electrode A side becomes a positive electrode. It will be superimposed. Alternatively, the secondary winding of the pulse transformer may be inserted not between the hot output terminal and the line L1 but between the reference output terminal and the line L2. The secondary winding of the pulse transformer may be divided and inserted into the hot side and the cold side.
(2) Although the full bridge circuit 30 is shown as an AC output circuit, other types of circuits such as a push-pull circuit and a half-full bridge circuit may be used as long as an AC voltage can be supplied.
(3) Although the resistor 45 is inserted between the capacitor 46 and the diode 44 in FIGS. 1 and 5, it may be inserted between the diode 44 and the line L1 or L2.

30. Full bridge circuit 40, 40 '. Igniter circuits 42, 45. Resistors 43, 46. Capacitor 44. Diode 47. Discharge gap 48. Pulse transformer 50. High pressure discharge lamp
51. Trigger line 55. Reflector 61. High pressure discharge lamp lighting device (lighting device)
62. Cases A and B. Electrodes L1, L2. Line Th. Hot side output terminal Tc. Reference (cold side) output end

Claims (5)

A high pressure discharge lamp lighting device,
An AC output circuit (30) for outputting an AC voltage between the first line (L1) and the second line (L2), and a hot-side output terminal (Th) and a reference output by superimposing a pulse voltage on the AC voltage An igniter circuit (40) applied to the high-pressure discharge lamp from the end (Tc)
The second line is connected to the reference output end,
The igniter circuit is
A first capacitor (43) connected to the second line;
A first resistor (42) connected between the first capacitor and the first line;
A second capacitor (46) connected to the second line;
A diode (44) connected between the second capacitor and the first line with a cathode on the first line side;
A discharge gap (47) connected between the first capacitor-side point (430) of the first capacitor and the diode-side point (460) of the second capacitor; and a primary winding A transformer (48) having a line connected in series to the discharge gap and a secondary winding connected between the first line and the hot output end
High pressure discharge lamp lighting device equipped with. A high pressure discharge lamp lighting device,
An AC output circuit (30) for outputting an AC voltage between the first line (L1) and the second line (L2), and a hot-side output terminal (Th) and a reference output by superimposing a pulse voltage on the AC voltage An igniter circuit (40) applied to the high-pressure discharge lamp from the end (Tc)
The second line is connected to the reference output end,
The igniter circuit is
A first capacitor (43) connected to the first line;
A first resistor (42) connected between the first capacitor and the second line;
A second capacitor (46) connected to the first line;
A diode (44) connected between the second capacitor and the second line with the cathode on the first line side;
A discharge gap (47) connected between the first capacitor-side point (430) of the first capacitor and the diode-side point (460) of the second capacitor; and a primary winding A transformer (48) having a line connected in series to the discharge gap and a secondary winding connected between the first line and the hot output end
High pressure discharge lamp lighting device equipped with. In the high pressure discharge lamp lighting device according to claim 1 or 2,
The high pressure discharge lamp lighting device in which the winding direction of the primary winding and the secondary winding of the transformer is determined so that the pulse voltage has the same polarity with respect to the half cycle of the AC voltage on which the pulse voltage is superimposed.   The high-pressure discharge lamp lighting device according to claim 1 or 2, further comprising a second resistor (45) connected in series with the second capacitor.   The high pressure discharge lamp lighting device (61) according to claim 1 or 2, comprising a first electrode (A) connected to the hot-side output end and a second electrode (B) connected to the reference output end. A high pressure discharge lamp (50), a reflector (55) to which the high pressure discharge lamp is attached, and a light source device comprising the high pressure discharge lighting device and a housing (62) containing the reflector, wherein the high pressure discharge lamp comprises: A light source device comprising an auxiliary winding (51), wherein one end of the auxiliary winding is electrically connected to the first electrode, and the other end is wound around the second electrode.

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