JP2002075672A - Igniter, high pressure discharge lamp lighting device and lighting device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To realize miniaturization of an igniter, while securing electrical dielectric strength of a pulse transformer, in the igniter that generates a high- voltage pulse. SOLUTION: A pulse transformer is composed without using a coil bobbin by using the pulse transformer in which a primary coil and a secondary coil are directly wound to a bar-like core made of ferrite of which specific resistance is 104 Ω.m or more.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an igniter for generating a high-pressure pulse necessary for starting a high-pressure discharge lamp,
The present invention relates to a high pressure discharge lamp lighting device and a lighting device using the igniter.

[0002]

2. Description of the Related Art There is known a high-pressure discharge lamp which starts by applying a high-voltage pulse between electrodes. In recent years, in order to reliably start and restart the high-pressure discharge lamp, the applied high-voltage pulse has been increased from 10 kV to about 30 kV.

A pulse transformer of an igniter for starting a high-pressure discharge lamp for generating a high-pressure pulse is as follows.
As described in Japanese Patent Application Laid-Open No. H10-241971, a pulse transformer formed by winding a primary coil and a secondary coil around a coil bobbin having a hollow hole and inserting a core into the hollow hole of the coil bobbin ( Conventional example) is disclosed.

[0004]

The coil bobbin having the structure of the above-mentioned conventional example is made of polyphenylene oxide (NORYL) resin or the like in order to secure insulation and withstand voltage against a high-voltage pulse. However, with such a resin, it is difficult to ensure heat resistance.For example, when an overcurrent flows through a coil wound around a bobbin when a lamp as a load is short-circuited, the coil generates heat, and The bobbin may be deformed by heat. In this case, even if the cause of the overcurrent is eliminated by replacing the lamp or the like, after the bobbin is deformed, the arrangement of the core and coil housed in the bobbin is changed, and the pulse Transformer characteristics could not be sufficiently obtained, high-voltage pulses could not be generated, and the lamp could not be turned on.

[0005] Further, with the downsizing of the lighting device, downsizing of the built-in lighting device and igniter is also required. However, in a configuration like the conventional example, the core is housed in the hollow portion of the bobbin. In addition, it is necessary to increase the thickness of the bobbin due to the problem of the pressure resistance of the bobbin. Also, as a characteristic of the pulse transformer, a sufficient high-voltage pulse cannot be generated unless the cross-sectional area of the core is not less than a certain value.
For these reasons, it has been difficult to reduce the size, especially the thickness, of the pulse transformer.

It is therefore an object of the present invention to provide an igniter capable of ensuring the reliability of a pulse transformer and achieving downsizing, a high-pressure discharge lamp lighting device and an illuminating device using the igniter.

[0007]

An igniter according to the present invention comprises a rod-shaped core made of ferrite having a specific resistance of 10 ⁴ Ω · m or more, and a primary winding and a secondary winding wound directly on the core. And an oscillation circuit capable of driving the pulse transformer.

In the present invention and each of the following inventions, definitions and technical meanings of terms are as follows unless otherwise specified.

In the pulse transformer, a primary winding and a secondary winding are directly wound around a rod-shaped core. The core has a rod-like shape because the secondary winding that generates high voltage is wound in multiple layers to prevent the occurrence of sparks due to the application of high voltage between the stacked windings. This is because the wires are not wound in multiple layers and are arranged in a line. With such a configuration, it is not necessary to ensure insulation between the windings when forming a multilayer winding, an insulating material between the windings is not required, and the pulse transformer can be downsized.

The core is required to be made of a magnetic material and have high impedance. The high-impedance material indicates a state where the specific resistance value is as high as 10 ⁴ Ω · m. If the specific resistance value is smaller than 10 ⁴ Ω · m, there is a possibility that a spark may occur because the high voltage pulse of 10 kV or more generated from the pulse transformer cannot be tolerated. For this reason, the specific resistance value is desirably higher, and is desirably 10 ⁶ Ω · m or more.

As such a material, a Ni—Zn type, Cu
It is possible to use -Zn-based ferrite and those containing these powders in a resin.

Further, flanges can be provided at both ends of the rod-shaped core and at the boundaries between the primary winding and the secondary winding to prevent winding collapse. By forming this flange from the core material, sparking between the windings can be suppressed because of excellent insulation and pressure resistance. The flanges can be formed integrally or separately from the same core material. By integrally molding the flange and the core, the pressure resistance of the core and the insulation between the coils can be further ensured.

In order to prevent the insulation of the pulse transformer, the withstand voltage and the leakage of the high voltage, it is preferable to surround the entire pulse transformer with a resin. Further, the primary winding and the secondary winding can be further covered with an insulating material.

The oscillating circuit is a circuit for generating a high-voltage pulse by switching a voltage stored in a pulse transformer or by rapidly applying a voltage to the pulse transformer, and includes a switching element such as a discharge gap. It is allowed to include a charge / discharge capacitor.

It is desirable that the igniter incorporates these pulse transformers and oscillation circuits in an insulating case to prevent leakage of high voltage to nearby electric components such as lighting circuits and users.

The case is formed of an insulating material such as a phenol resin, and prevents the high voltage pulse from leaking to the outside.
Further, inside the case, a partition made of an insulating resin is arranged between the pulse transformer and the oscillation circuit in order to ensure a withstand voltage between the pulse transformer and the oscillation circuit. Also,
The partition may be formed so as to surround the pulse transformer and the oscillation circuit, respectively. This configuration of the case prevents leakage of the high-voltage pulse to the outside.

As the insulating resin, an epoxy resin, a silicon resin and a polyurethane resin are allowed. It is sufficient that at least both ends of the pulse transformer are filled with the insulating resin, and it is also allowable to fill the entire case.

According to the first aspect of the present invention, the core of the pulse transformer is made of ferrite having a specific resistance of 10 ⁴ Ω · m or more, so that the core and the primary winding and the secondary winding are separated from each other. , And can be formed without using a coil bobbin as in the related art.

Therefore, the generation of the high-voltage pulse can be stabilized without changing the characteristics of the pulse transformer due to the deformation of the coil. Further, since the coil bobbin is not required, the pulse transformer can be downsized.

According to a second aspect of the present invention, there is provided the igniter according to the first aspect, wherein the core of the pulse transformer is made of a Ni—Zn ferrite.

Since the Ni—Zn ferrite has excellent high-frequency characteristics on the order of MHz, it is effective for generating a high-pressure pulse for lighting a high-pressure discharge lamp.

The igniter according to the third aspect of the present invention is characterized in that the igniter is Ni-Z
a pulse transformer having a flat rod-shaped core made of n-type ferrite and a primary winding wound directly on the center of the rod-shaped core and secondary windings wound on both sides of the primary winding; including a flat-shaped charging capacitor An oscillation circuit capable of driving the pulse transformer; and an igniter case accommodating the pulse transformer and the oscillation circuit.

According to the third aspect of the present invention, the pulse transformer and the charging capacitor can be arranged to face each other by forming the flat charging capacitor and the flat bar-shaped pulse transformer to have substantially the same width. Thus, an igniter that can be mounted in a small size can be configured.

According to a fourth aspect of the present invention, there is provided a lighting device for a high pressure discharge lamp, comprising: the igniter according to any one of the first to third aspects;
A ballast for stably lighting the high-pressure discharge lamp.

The ballast only needs to have a function of maintaining stable operation of the high-pressure discharge lamp. Electromagnetic ballasts such as a choke coil type and a leakage transformer type are also allowed in addition to an electronic ballast. .

According to the invention of claim 4, in addition to the effect of the invention of any one of claims 1 to 3, the igniter can be downsized, so that the high pressure discharge lamp lighting device can also be downsized.

According to a fifth aspect of the present invention, there is provided a lighting device comprising: a high-pressure discharge lamp; a high-pressure discharge lamp lighting device according to the fourth aspect; and a lighting device body accommodating the high-pressure discharge lamp and the high-pressure discharge lamp lighting device. ing.

The lighting device is any lighting device that utilizes the light emission of the high-pressure discharge lamp, and allows general lighting devices, projector devices, and headlight devices for automobiles.

According to the fifth aspect of the present invention, it is possible to provide an illuminating device capable of preventing the leakage of the high-voltage pulse and ensuring the safety of the user, and to reduce the size of the illuminating device.

[0030]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of an igniter and a high pressure discharge lamp lighting device using the igniter according to the present invention will be described with reference to FIGS. 1, 2 and 3. FIG. This embodiment shows an example of a lighting device using a metal halide lamp as the high-pressure discharge lamp LP. 1 is a perspective view of a pulse transformer, FIG. 2 is a partial cross-sectional view of an igniter, FIG. 3 is a circuit diagram of the igniter, and FIG. 4 is a schematic circuit diagram of a high-pressure discharge lamp lighting device. The same parts as those in FIG. 1 are denoted by the same reference numerals.

In the figure, a pulse transformer 1 is composed of a core 1
The primary winding 2c is directly wound around the core between the secondary windings 2a, 2b and the secondary windings 2a, 2b at both ends of the core a.

The core 1a is made of a Ni—Zn ferrite having a specific resistance of 10 ⁸ Ω ·
m. The shape of the core 1a is 50 mm long and 20 m wide
m, a flat shape with a height of 5 mm. A flange 1b having a height of about 2 mm is provided between both ends of the core 1a and between the primary winding and the secondary winding, and is formed integrally with the core 1a.

The secondary windings 2a and 2b are wound so as to be aligned winding from the center primary winding 2c side of the core 1a toward both ends of the core 1a. By winding in this manner, the distance between the output terminals of the secondary windings 2a and 2b can be increased, and the occurrence of sparks between the output terminals can be suppressed.

The oscillation circuit 3 includes a step-up transformer 31, a high-voltage oscillation discharge gap 32, and a high-voltage oscillation capacitor 33.
It is composed of The high-voltage oscillation capacitor 33 has a length of 20 mm, a width of 20 mm, and a height of 5 mm based on its capacity. The high-voltage oscillation capacitor 33 is arranged below the secondary winding 2a, the step-up transformer 31 is arranged below the secondary winding 2b, and the high-voltage oscillation discharge gap 32 is arranged below the primary winding 2c. (See FIG. 2). By arranging in this way, each component can be arranged at the output end of the secondary winding 2b where a high-voltage pulse is generated without drawing out the wiring of each component, so that the occurrence of sparks between the wires can be prevented.
The components of the oscillation circuit 3 and the pulse transformer 2 are electrically connected to each other by an igniter internal substrate 34 and installed.

The pulse transformer 1 and the oscillation circuit 3 are partitioned by partition plates 101 and 102, respectively, and are filled with an insulating resin 103. Further, an igniter case 104 secures insulation and withstand voltage from peripheral circuits.

The partition plates 41 and 42 and the igniter case are made of polyphenylene oxide (NO.
RYL) resin, and an epoxy resin was used for the insulating resin 43. The igniter 10 is configured as described above.

Next, the configuration of the high pressure discharge lamp lighting device 40 will be described.

A filter circuit 41 is connected to a commercial power supply of 100 V AC, and this filter circuit 41 prevents a high frequency generated from a subsequent chopper circuit 43 or the like from being conducted to the commercial power supply AC.

The output of the filter circuit 41 is
2. Connected sequentially to the chopper circuit 43 and the smoothing circuit 44 to output a desired DC power supply.

The output of the rectifier circuit 42 is supplied to a chopper circuit 43
And to the auxiliary power supply circuit 45. The control circuit 46 operates using the output voltage of the auxiliary power supply circuit 45 as a power supply. The control circuit 46 includes the smoothing circuit 4
4 and the output of the chopper circuit 43 is controlled.

The output of the smoothing circuit 44 is connected to a primary oscillation circuit 47. The primary oscillation circuit 47 charges the charge output from the smoothing circuit 44 to the primary oscillation capacitor C1 and charges it to a desired voltage, and then switches the switching element S1.
At 1, the charge stored in the primary oscillation capacitor C <b> 1 is released and transmitted to the primary oscillation transformer 31 of the oscillation circuit 3.

In the case of this embodiment, the smoothing circuit 44
V DC voltage is output and the step-up transformer 31
The voltage is boosted to about 3 kV.

The voltage stepped up by the step-up transformer 31 is rectified by the sex current diode 36 of the oscillation circuit 3 and charged in the high-voltage oscillation capacitor 33. When the charging voltage of the high-voltage oscillation capacitor 33 exceeds a predetermined voltage, the electric charge charged in the high-voltage oscillation capacitor 33 by the high-voltage discharge gap 32 is released, and the primary winding 2 of the pulse transformer 2 is released.
2 is transmitted. The pulse transformer 2 oscillates a voltage corresponding to a turn ratio between the primary winding 22 and the secondary windings 23a and 23b. In the present embodiment, a pulse boosted to 10 to 15 kV is applied to both ends of the high-pressure discharge lamp LP in opposite polarities to the secondary windings 23a and 23b. That is, since a potential of 20 to 30 kV is applied between the electrodes of the high-pressure discharge lamp LP, the high-pressure discharge lamp LP starts lighting.

In this embodiment, in order to generate a high-voltage pulse of 20 to 30 kV, the potential is raised in two steps to generate a high-voltage pulse. May be used. In this embodiment, the transformer for boosting at one stage is also housed in the igniter case to ensure the withstand voltage against the boosted voltage.

Although the igniter case can be covered with a metal case for the electromagnetic shield of the igniter, since the withstand voltage of the portion where the high-voltage pulse is generated is secured, the igniter case can be connected to the metal case. Sparking or the like due to application of a pulse can be prevented.

A second embodiment of the present invention will be described with reference to FIG. In the present embodiment, the liquid crystal projector 5 is formed by using the high-pressure discharge lamp LP and the high-pressure discharge lamp lighting device 40 described above. That is, the liquid crystal projector 5 includes a high-pressure discharge lamp LP connected to the high-pressure discharge lamp lighting device 40, a liquid crystal display panel 53 driven by the liquid crystal driving unit 52, and a high-pressure discharge lamp LP.
Is fixed to a reflecting mirror 51, and an optical system 55 for projecting the irradiation of the high-pressure discharge lamp LP onto the screen 54 by passing the light through the liquid crystal display panel 53, that is, the mirror 56 and the lens 57
Lighting means 40, high pressure discharge lamp LP, reflecting mirror 51,
Liquid crystal driving means 52, liquid crystal display panel 53 and optical system 5
5 is an example of a liquid crystal projector 5 including a housing 59 having an opening 58 formed therein for receiving light transmitted through a liquid crystal display panel 53 and projecting the light to a screen 54.

[0047]

According to the first aspect of the present invention, the core of the pulse transformer is made of ferrite having a specific resistance of 10 ⁴ Ω · m or more, so that the core, the primary winding, and the secondary winding are formed. The withstand voltage between wires can be ensured, and it can be formed without using a conventional coil bobbin.

Therefore, the generation of the high-voltage pulse can be stabilized without changing the characteristics of the pulse transformer due to the deformation of the coil bobbin. Further, since the coil bobbin is not required, the pulse transformer can be downsized.

According to the second aspect of the present invention, in addition to the effect of the first aspect of the present invention, the Ni-Zn based ferrite is excellent in high-frequency characteristics on the order of MHz, so that a high-pressure pulse for lighting a high-pressure discharge lamp can be provided. Is effective in generating

According to the third aspect of the present invention, in addition to the effects of the second aspect of the present invention, by forming the flat charging capacitor and the flat pole-shaped pulse transformer to have substantially the same width, Since the charging capacitors can be arranged to face each other, an igniter that can be mounted in a small size can be configured.

According to the invention of claim 4, in addition to the effect of the invention of any one of claims 1 to 3, the igniter can be downsized, so that the high pressure discharge lamp lighting device can also be downsized.

According to the fifth aspect of the present invention, it is possible to provide an illuminating device capable of preventing the leakage of the high-voltage pulse and ensuring the safety of the user, and to reduce the size of the illuminating device.

[Brief description of the drawings]

FIG. 1 is a perspective view of a pulse transformer according to an embodiment of the present invention.

FIG. 2 is a partial cross-sectional view of an igniter according to an embodiment of the present invention.

FIG. 3 is a circuit diagram of the igniter.

FIG. 4 is a block diagram of a high pressure discharge lamp lighting circuit according to an embodiment of the present invention.

FIG. 5 is a schematic diagram of a projector according to an embodiment of the present invention.

[Explanation of symbols]

Reference Signs List 10 igniter 1 pulse transformer 1a core 2a, 2b secondary winding 2c 1
Next winding 10 ... igniter 3 ... oscillation circuit 4 ... high pressure discharge lamp lighting device 5 ... projector device LP ... high pressure discharge lamp

Claims (5)

[Claims] 1. A pulse transformer having a rod-shaped core made of ferrite having a specific resistance of 10 ⁴ Ω · m or more and a primary winding and a secondary winding directly wound around the core; An oscillating circuit; 2. The igniter according to claim 1, wherein the core of the pulse transformer is made of a Ni—Zn ferrite. 3. A pulse transformer having a flat rod-shaped core made of Ni—Zn ferrite, a primary winding directly wound around the center of the rod-shaped core, and secondary windings wound on both sides of the primary winding; An igniter comprising: an oscillation circuit capable of driving a pulse transformer including a flat charging capacitor; and an igniter case accommodating the pulse transformer and the oscillation circuit. 4. A high pressure discharge lamp lighting device, comprising: the igniter according to claim 1; and a ballast for stably lighting the high pressure discharge lamp. 5. A lighting device comprising: a high-pressure discharge lamp; a high-pressure discharge lamp lighting device according to claim 4; and a lighting device main body containing the high-pressure discharge lamp and the high-pressure discharge lamp lighting device. apparatus.