JP2008027821A - Transformer device for high-voltage pulse generating, discharge lamp lighting device, illumination device, and projector device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reduce an inductance value of a secondary winding without changing parameters when these parameters such as a material quality of a magnetic body of a core, a core diameter, the length and a turn number of windings are already determined in a transformer device for high voltage pulse generation to generate a high voltage pulse in order to start/restart a discharge lamp. <P>SOLUTION: At the core 30 made of a magnetic body around which a rectangular copper wire is wound edgewise as the secondary winding 20 to generate the high voltage pulse, an open hole 31 or a groove is installed in the axial direction of the core 30. By penetrating this open hole 31 or the groove in the axial direction of the core 30, an output wire 23 of the high voltage pulse may be installed in this open hole 31 or the groove. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to, for example, a high voltage pulse generating transformer device used for generating a high voltage pulse for starting and restarting a high pressure discharge lamp such as a mercury lamp or a metal halide lamp, a discharge lamp lighting device using the same, and illumination The present invention relates to a device and a projector device.

  Conventionally, a high pressure discharge lamp lighting device for lighting a high pressure discharge lamp (HID lamp) such as a mercury lamp or a metal halide lamp has been provided. In this high pressure discharge lamp lighting device, a device for generating a high voltage pulse called an igniter is used to start and restart the high pressure discharge lamp, and this igniter is used to convert a low voltage pulse into a high voltage pulse. In addition, a transformer device for generating a high voltage pulse is used.

  Conventional general high-voltage pulse generating transformer devices have a primary winding and a secondary winding directly wound around a core made of a magnetic material at a ratio for securing a desired high voltage, or a bobbin is interposed. And was winding. Among these, since a high voltage is generated in the secondary winding, it is more advantageous in terms of withstand voltage design to use a flat copper wire (see FIG. 2). Since the thickness can be suppressed, the size in the thickness direction can be reduced as compared with the case of using a circular copper wire.

  The secondary winding of the high voltage pulse generating transformer device is used in series with the discharge lamp in order to apply a high voltage pulse to the discharge lamp (see FIG. 8). For this reason, after the discharge lamp breaks down, there is no problem at the time of steady operation in which the discharge lamp is driven by a low-frequency rectangular wave current, but in order to quickly shift from the glow discharge state immediately after the breakdown to a stable arc discharge state, When a high frequency current is caused to flow through the discharge lamp, the inductance component of the secondary winding of the high voltage pulse generating transformer device acts as a current limiting impedance on the high frequency current.

  In order to reduce this impedance, generally, means such as reducing the number of turns of the winding, reducing the magnetic permeability of the core, or reducing the diameter and length of the core are used. However, when the number of turns of the secondary winding is lowered, the high voltage pulse applied to the discharge lamp is lowered, which is not preferable. When the core diameter is reduced, the ratio of the inner diameter to the outer diameter is limited in order to edgewise wind a rectangular copper wire, and the core diameter that can be wound is limited. For example, in the case of a flat copper wire directly wound around a φ9 cylindrical core (rod core), the ratio of the inner diameter of the winding determined by the outer diameter of the core and the outer diameter determined by (inner diameter + width of the rectangular copper wire) is 50. If it exceeds%, the general winding method tends to increase the elongation of the insulating film on the outside of the flat copper wire, resulting in severe quality.

  In addition, it is conceivable that a rectangular copper wire is wound edgewise on the bobbin and a core having a smaller diameter than that in the case of direct winding is inserted into the bobbin. However, since the distance between the core and the winding is increased, the coupling is poor. It is not preferable.

Patent Document 1 discloses an electromagnetic device in which a metal core is inserted into a core filling hole in which a flat copper wire is wound edgewise. This is because the filling hole in which the metal core is inserted is an opening hole. Or since it is not a groove, the magnetic permeability of the core does not decrease, and there is no effect of reducing the inductance value of the winding.
JP 2002-93631 A

  The present invention has been made in view of the above points, and is used in a transformer device for generating a high voltage pulse for starting and restarting a discharge lamp, connected in series to the discharge lamp. It is an object to reduce the inductance value of the secondary winding.

  In order to solve the above-mentioned problem, the invention of claim 1 is a high voltage pulse generating transformer device for generating a high voltage pulse for starting and restarting a discharge lamp, as shown in FIGS. An opening hole 31 or a groove 32 is provided in the axial direction of the core 30 in the core 30 made of a magnetic material in which a flat copper wire is edgewise wound as the secondary winding 20 for generating a high voltage pulse. Is.

  The invention of claim 2 is characterized in that, in claim 1, the opening hole 31 or the groove 32 is penetrated in the axial direction of the core 30 (see FIGS. 5 and 7).

  The invention of claim 3 is characterized in that, in claim 2, the output line 23 of the high voltage pulse is provided in the opening hole 31 or the groove 32 (see FIGS. 4 and 6).

  According to the first aspect of the present invention, by providing the opening hole or groove in the axial direction of the core, the inductance value of the secondary winding of the transformer can be reduced without changing the workability of the winding.

  According to the second aspect of the present invention, since the opening hole or the groove is penetrated in the axial direction of the core, the processing becomes easy.

  According to the invention of claim 3, since the space can be effectively utilized by passing the output line of the high voltage pulse through the opening hole or groove, it contributes to the downsizing of the transformer device for generating the high voltage pulse and the primary winding. An effect of increasing the coupling between the wire and the secondary winding is also obtained.

(Embodiment 1)
FIG. 1 is a perspective view showing the appearance of a high voltage pulse generating transformer device (hereinafter simply referred to as a pulse transformer) according to Embodiment 1 of the present invention. This pulse transformer includes a core 30 made of a columnar magnetic body, a secondary winding 20 wound around the outer periphery of the core 30, and a secondary winding 20 and the core 30 accommodated in an opening on one side. And a primary winding 10 wound around the outer periphery of the bobbin 40.

  As shown in FIG. 2 (a), the secondary winding 20 is a rectangular copper wire (width including an insulating film: 2.0 mm, thickness: 0.15 mm) as shown in FIG. 2 (b). The winding end 20 a on the opening side of the bobbin 40 is connected to the low voltage side terminal 21, and the winding end 20 b on the inner side of the bobbin 40 is connected to the high voltage side terminal 22 via the high voltage pulse output line 23. It is connected. The output line 23 of the high voltage pulse is covered with an insulating member.

  As shown in FIGS. 3A and 3B, the core 30 is an insulating core made of, for example, a high-resistance ferrite formed in a columnar shape, whereby the secondary winding 20 is directly wound around the core 30. Since insulation is ensured when worn, it is not necessary to interpose a bobbin between the core 30 and the secondary winding 20.

  In the present invention, as a means for reducing the inductance value of the secondary winding of the pulse transformer, as shown in FIGS. 3A and 3B, an opening hole 31 or a groove 32 is provided in the core 30 made of a magnetic material. It is provided in the axial direction. By adjusting the size and length of the opening hole 31 or the groove 32, the inductance value can be reduced to a desired value.

  The bobbin 40 is formed in a box shape using an insulating resin, and one surface side that houses the core 30 around which the secondary winding 20 is wound is opened. The bobbin 40 is embedded with terminals 11 and 12 respectively connected to the low voltage side terminal 21 of the secondary winding 20 and both ends of the primary winding 10 so as to partially protrude from the lower surface side. A plurality of ribs 41 are provided on the outer peripheral portion of the bobbin 40 so that the primary winding 10 can be wound at a predetermined pitch.

  Insulating resin may be filled from the opening of the bobbin 40. At this time, the filling resin may enter the opening hole 31 or the groove 32 of the core 30, but since the permeability of the resin is low, the effect of reducing the inductance value of the secondary winding is affected. It never happens.

  Thus, by using the core 30 provided with the opening hole 31 and the groove 32 and replacing the core used in the conventional pulse transformer, the inductance value of the secondary winding can be reduced with the same shape and the same size. Can be planned.

(Embodiment 2)
FIG. 4 is a perspective view showing the appearance of the pulse transformer according to the second embodiment of the present invention. In the present embodiment, in consideration of the workability of the core, a shape in which the groove 32 is provided on the entire side surface of the core 30 as shown in FIG. Moreover, you may employ | adopt what provided the opening hole 31 penetrated to the axial direction of the core 30 like Fig.5 (a). As described above, if the structure has the opening hole 31 or the groove 32 penetrating in the axial direction of the core 30, the output line 23 of the high voltage pulse can be passed through the opening hole 31 or the groove 32, and the space can be effectively used. .

(Embodiment 3)
FIG. 6 is a perspective view showing the appearance of the pulse transformer according to the third embodiment of the present invention. In the present embodiment, a cylindrical core 30 having an opening hole 31 at the center is formed by combining two cores 30a and 30b as shown in FIG. 7 instead of an integral core.

  In the structure as shown in FIG. 1, the output line 23 is sandwiched between the primary winding 10 and the secondary winding 20, so the bobbin 40 is enlarged, but as shown in FIG. If the core shape is provided with a groove 32 on the entire side surface of the core 30 in order to reduce the inductance, or the core shape is provided with a through hole 31 as shown in FIG. 6, a high voltage is applied to the groove 32 or the hole 31. Since the pulse output line 32 can be passed, the bobbin 40 can be miniaturized by making effective use of the space, and the degree of coupling can be reduced by reducing the distance between the primary winding 10 and the secondary winding 20. Can be increased.

(Embodiment 4)
The pulse transformer PT according to any of the first to third embodiments described above includes, for example, a high-pressure discharge lamp La such as a mercury lamp or a metal halide lamp as shown in FIG. 8, and a discharge lamp for lighting the high-pressure discharge lamp La. In an illuminating device provided with a lighting device, it is used as an igniter Ig for a discharge lamp lighting device. The pulse transformer PT, the capacitor C3 connected to the primary winding N1, the charging resistor R4 and the diode D2, and the discharging switch element G constitute an igniter Ig.

  In this discharge lamp lighting device, the voltage supplied from the DC power source 1 is controlled by the converter circuit 2, the inverter circuit 3 is provided at the output terminal of the converter circuit 2, the discharge lamp La is connected to the output terminal of the inverter circuit 3, and It has a capacitor C2 connected in parallel and an inductor L2 connected in series.

  The converter circuit 2 includes a switching element Q1, an inductor L1, and a diode D1, and here has a configuration of a step-down chopper circuit. The output voltage of the converter circuit 2 is detected by the resistors R1 and R2, the output current is detected by the resistor R3, and the switching element Q1 is detected by the PWM control circuit 6 based on the result of calculating the detected voltage / current by the arithmetic circuit 5. Is driven on and off at a high frequency. Thereby, according to the state of the discharge lamp La, the capacitor | condenser C1 is charged with the DC voltage which voltage-converted the output voltage of the DC power supply 1. FIG. Here, the DC power source 1 may be, for example, a DC voltage obtained by rectifying and smoothing a commercial AC power source with a boost chopper circuit or the like. The converter circuit 2 may be any circuit that can convert the voltage of the DC power supply 1.

  The inverter circuit 3 is a full bridge circuit composed of four switching elements Q2 to Q5. The switching elements Q2 and Q5 are on, the switching elements Q3 and Q4 are off, and the switching elements Q2 and Q5 are off. When the switching elements Q3, Q4 are alternately switched on, the input DC voltage is converted into an AC voltage and output.

  The drive circuit 4 performs on / off control of the switching elements Q2, Q3 and the switching elements Q4, Q5 of the inverter circuit 3. At the time of start-up, a pair of switching elements Q2 and Q5 and switching elements Q3 and Q4 of the inverter circuit 3 are alternately turned on and off at a high frequency to be connected in series with a capacitor C2 connected in parallel to the discharge lamp La. The inductor L2 is resonated, and a voltage higher than the output of the converter circuit 2 is applied to both ends of the discharge lamp La. Further, the voltage is used to charge the capacitor C3 with energy, and the energy is discharged to the primary winding N1 of the pulse transformer PT when the voltage-responsive switch element G is turned on. The energy is transmitted to the secondary winding N2 of the pulse transformer PT, and a voltage in which the high voltage pulse is superimposed on the resonance voltage is applied to the discharge lamp La.

  A schematic waveform of the voltage applied to the discharge lamp La is shown in FIG. This voltage is applied to the discharge lamp La, causing the discharge lamp La to break down and light up. Further, after the dielectric breakdown, as shown in FIG. 10, a high-frequency current is allowed to flow through the discharge lamp La, whereby a stable lighting state (arc discharge state) can be shifted more quickly.

  With this circuit configuration, the discharge lamp La breaks down, and the high-frequency current flowing through the discharge lamp La while the inverter circuit 3 is operating at a high frequency is connected in series to the inductor L2 and the discharge lamp La of the pulse transformer PT. Limited by the impedance of the secondary winding N2.

  Thus, in the igniter Ig that is a lighting start device used in the high pressure discharge lamp lighting device, the secondary winding N2 of the pulse transformer PT is connected in series to the discharge lamp La. For this reason, the impedance can be almost ignored during steady operation in which current flows at a low frequency. However, when attempting to flow a high-frequency current immediately after starting, the inductance of the pulse transformer PT of the igniter Ig becomes a current-limiting impedance. Since the current is limited, the circuit design is a great restriction.

  For example, when the inductance value of the secondary winding N2 of the pulse transformer PT is 100 μH and the high frequency output of the inverter circuit 3 is operated at 40 KHz, the impedance ωL of the secondary winding N2 of the pulse transformer PT is about 25Ω. It is necessary to reduce this impedance and reduce the restriction on the current flowing through the lamp as much as possible.

  In the case of a general pulse transformer, the inductance value is determined by the material of the core magnetic material, the core diameter, the length, and the number of turns of the winding. Therefore, when these parameters are already determined, as in the first to third embodiments, by providing an opening hole or groove in the axial direction of the core, the inductance value of the pulse transformer is reduced, and at a high frequency at the start Improve impedance when operated. As a result, a large high-frequency current can be passed after dielectric breakdown to promptly shift to a stable lighting state (arc discharge state).

(Embodiment 5)
The discharge lamp lighting device according to the fourth embodiment described above can be used for lighting a discharge lamp serving as a light source of a projector device. FIG. 11 is a schematic configuration diagram showing the internal configuration of the projector device 50. In the figure, 51 is a projection window, 52 is a power supply unit, 53a, 53b and 53c are cooling fans, 54 is an external signal input unit, 55 is an optical system, 56 is a main control board, 60 is a discharge lamp lighting device, La Is a discharge lamp. A main control board 56 is mounted in a frame indicated by a broken line. In the middle of the optical system 55, image display means (a transmissive liquid crystal display panel or a reflective image display element) that transmits or reflects light from the discharge lamp La is provided. The optical system 55 is designed to project the reflected light onto the screen.

It is a perspective view which shows the external appearance of the pulse transformer of Embodiment 1 of this invention. It is a figure which shows the structure of the coil | winding used for the pulse transformer of Embodiment 1-3 of this invention, (a) is a perspective view of the secondary winding wound edgewise, (b) is a perspective view of a rectangular copper wire. FIG. It is a perspective view which shows the external appearance of the core used for Embodiment 1 of this invention. It is a perspective view which shows the external appearance of the pulse transformer of Embodiment 2 of this invention. It is a perspective view which shows the external appearance of the core used for Embodiment 2 of this invention. It is a perspective view which shows the external appearance of the pulse transformer of Embodiment 3 of this invention. It is a perspective view which shows the external appearance of the core used for Embodiment 3 of this invention. It is a circuit diagram of the discharge lamp lighting device of Embodiment 4 of the present invention. It is a voltage waveform diagram which shows operation | movement of the discharge lamp lighting device of Embodiment 4 of this invention. It is a current waveform diagram which shows operation | movement of the discharge lamp lighting device of Embodiment 4 of this invention. It is a schematic block diagram which shows the internal structure of the projector apparatus of Embodiment 5 of this invention.

Explanation of symbols

10 Primary winding 20 Secondary winding 30 Core 31 Opening hole 32 Groove 40 Bobbin

Claims (6)

A core made of a magnetic material in which a rectangular copper wire is edgewise wound as a secondary winding for generating a high-voltage pulse in a transformer device for generating a high-voltage pulse for starting and restarting a discharge lamp In addition, a high voltage pulse generating transformer device having an opening hole or groove in the axial direction of the core. 2. The high voltage pulse generating transformer device according to claim 1, wherein the opening hole or the groove is penetrated in the axial direction of the core. 3. The high voltage pulse generating transformer device according to claim 2, wherein an output line of a high voltage pulse is provided in the opening hole or groove. A discharge lamp lighting device comprising the transformer device for generating a high voltage pulse according to any one of claims 1 to 3 in an igniter for starting and restarting a discharge lamp. An illumination device comprising at least the discharge lamp lighting device according to claim 4 and a discharge lamp driven by the discharge lamp lighting device. A projector device comprising the illumination device according to claim 5 as a light source.

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