Patent Publication Number: US-7915828-B2

Title: High-voltage pulse generator, and lighting apparatus and vehicle having the same

Description:
TECHNICAL FIELD 
     The present invention relates to a high-voltage pulse generator used for starting up and re starting up a high-brightness discharge lamp such as a mercury lamp and a metal halide lamp, and a lighting apparatus and a vehicle employing the high-voltage pulse generator. 
     BACKGROUND ART 
     Conventionally, there were known lighting apparatuses for lighting a high-brightness discharge lamp (hereinafter, referred to as an HID lamp) such as a mercury lamp and a metal halide lamp. Such lighting apparatuses employ a high-voltage pulse generator (also referred to as a discharge lamp igniter) for instantaneously starting up or restarting up the HID lamp, in addition to an inverter for supplying power to the HID lamp. 
     As shown in  FIG. 13 , a high-voltage pulse generator  100  includes an IGN connector A having in put terminals IN 1  to IN 3  electrically connected to output terminals of an inverter and a socket B into which a cap E of an HID lamp DL is fitted. The high-voltage pulse generator  100  employs a pulse transformer (not shown) for converting a low-voltage pulse into a high-voltage pulse. 
     As shown in  FIG. 14 , such a high-voltage pulse generator  100  includes a pulse transformer PT in which a primary winding N 1  and a secondary winding N 2  are wound on a cylinder-shaped ferrite core  200 , terminals  201  and  201  electrically connected to both ends of the first primary winding N 1 , respectively, a high-voltage part terminal  202  and a low-voltage part terminal  203  electrically connected to both ends of the secondary winding N 2 , respectively, an insert molded member  204  into which the pulse transformer PT and the terminals  201  to  203  are inserted with the terminals  201  to  203  exposed, and a case  206  into which the insert molded member  204  is inserted, on which electronic components  205  constituting the high-voltage pulse generator  100  along with the pulse transformer PT are mounted, and which includes a socket B having an inner electrode OUT 1  and an outer electrode OUT 2  connected to an inner electrode and an outer electrode of the cap E of the HID lamp DL (Patent Document 1). 
     A circuit configuration of the high-voltage pulse generator  100  is now described with reference to  FIG. 15 . As shown in  FIG. 15 , the high-voltage pulse generator  100  includes a high-voltage part input terminal IN 1  and low-voltage part input terminals IN 2  and IN 3 , which constitute the IGN connector A, electrically connected to the output terminals of the inverter, a pulse generating capacitor C connected between the input terminals IN 1  and IN 3 , a surge absorber ZNR such as a two-way diode and a varistor connected between the input terminals IN 1  and IN 2 , a resistor R connected in parallel to the capacitor C so as to discharge electric charges remaining in the capacitor C and the surge absorber ZNR, a pulse transformer PT having a primary winding N 1  connected in parallel to the capacitor C and a secondary winding N 2  disposed between the input terminal IN 1  and the inner electrode OUT 1  of the socket B, and a high-voltage pulse generating discharge switch (discharge gap) SG for switching a discharge path from the capacitor C to the primary winding N 1 . The input terminal IN 2  is directly connected to the outer electrode OUT 2  of the socket B. Accordingly, in the circuit of the high-voltage pulse generator  100 , a portion denoted by reference numeral HV in  FIG. 15  serves as a high-voltage part circuit and a portion denoted by a reference numeral LV serves as a low-voltage part circuit. Specifically, a loop circuit, which is denoted by a reference numeral P, including the capacitor C, the primary winding N 1 , and the discharge switch SG forms a pulse generator through which large current, that is, pulses flows in the low-voltage part circuit LV. 
     Next, an operation of the high-voltage pulse generator  100  is described. When an output of the inverter is input to the input terminals IN 1  to IN 3  of the high-voltage pulse generator  100 , the capacitor C is charged by a potential difference between the input terminals IN 1  and IN 3 . When the voltage of the capacitor C becomes greater than a predetermined value, the discharge switch SG is turned on and a pulse is applied to the primary winding N 1 . In this way, when the pulse is applied to the primary winding N 1  of the pulse transformer PT, the pulse transformer PT outputs a high-voltage pulse out of the secondary winding N 2 . Accordingly, the high-voltage pulse is supplied from the inner electrode OUT 1  to the HID lamp DL and thus the HID lamp DL is ignited or re-ignited. 
     The high-voltage pulse generator  100  described above is used to instantaneously ignite and re-ignite the HID lamp in a lighting apparatus for lighting a HID lamp such as a mercury lamp and a metal halide lamp. A vehicle headlight apparatus  300  shown in  FIG. 16  is an example of such a lighting apparatus. 
     As shown in  FIG. 16 , the vehicle headlight apparatus  300  includes a box-shaped lamp housing  310 , a reflecting plate  320  for reflecting light emitted from an HID lamp DL, a high-voltage pulse generator  100  into which the HID lamp DL is fitted, and an inverter  330  electrically connected to the high-voltage pulse generator  100  so as to convert a DC voltage supplied from a 12V battery (not shown) of a vehicle into an AC voltage for driving the HID lamp. 
     The lamp housing  310  is formed in a box shape of which the front surface (left surface in  FIG. 16 ) is opened and is mounted with a front lens  311  to cover the opened front surface. In a rear wall of the lamp housing  310 , a circular lamp inserting hole  310   a  for inserting the HID lamp DL into the lamp housing  310  is formed in a portion corresponding to the back of the HID lamp DL disposed in the lamp housing  310 . A recessed portion  340   a  for receiving a part of the high-voltage generator  100  is formed in the circumferential edge of the lamp inserting hole  310   a , and a lamp interchanging maintenance cap  340  for closing the lamp inserting hole  310   a  is attached to the recessed portion  340   a  to be detachable from the back side. In addition, a power line inserting hole  310   b  for introducing a power line such as a harness H having one end connected to the inverter  330  into the lamp housing  310  is formed in the lower wall of the lamp housing  310 . A screw inserting hole (not shown) through which an optical axis adjusting screw  350  is inserted to pass through the rear wall is formed in the vicinity of the lamp inserting hole  310   a  formed in the rear wall of the lamp housing  310 . 
     The reflecting plate  320  is vertically rotatably received in the lamp housing  310  in the state that the reflecting surface is directed to the front side. The reflecting plate  320  can adjust the optical axis of light of the HID lamp DL in the vertical direction by forwardly and backwardly moving the optical axis adjusting screw  350  inserted in the lamp housing  310  through the screw inserting hole. The inverter  330  is attached to the lower surface of the lamp housing  310  from the lower side so as to close the power line inserting hole  310   b  and the harness H having one end connected to the inverter  330  is introduced into the lamp housing  310  through the power line inserting hole  310   b.    
     On the other hand, the high-voltage pulse generator  100  is disposed in the vicinity of the lamp inserting hole  310   a  of the lamp housing  310  in a state that the HID lamp DL is fitted into the socket B, the other end of the harness H is connected to the IGN connector A, the IGN connector A is directed upward, and the HID lamp DL is received in the lamp housing  310  through the lamp inserting hole  310   a . The maintenance cap  340  is attached to the rear wall of the lamp housing  310  in the state that a part of the high-voltage pulse generator  100  is received in the recessed portion  340   a.    
     [Patent Document 1] Japanese Patent Laid-open No. 2002-217050 (FIGS. 4, 12, and 16) 
     In recent years, decrease in size of such a vehicle headlight apparatus  300  was advanced, and thus decrease in size of the lamp inserting hole  310   a  has been required. 
     However, in the high-voltage pulse generator  100 , since the socket B is disposed on the high voltage side of the secondary winding N 2  of the pulse transformer PT, a distance between the center of the socket B and a portion farthest from the center in the case  206 , that is, a radius of rotation is increased. Thus, when the lamp inserting hole  310   a  is formed small to correspond to the high-voltage pulse generator  100 , the position of the HID lamp DL in the lamp housing  310  is inclined toward an edge of the lamp inserting hole  310   a , thereby badly deteriorating workability to fit the HID lamp DL very much. On the contrary, when the position of the HID lamp DL is set in the vicinity of the center of the lamp inserting hole  310   a  in consideration of the workability to fit the HID lamp DL, the lamp inserting hole  310   a  should be enlarged in accordance with the radius of rotation of the high-voltage pulse generator  100 . Accordingly, it is not possible to accomplish the decrease in size. 
     Such a problem could be solved by reducing the radius of rotation of the high-voltage pulse generator  100 , that is, by disposing the socket B in the vicinity of the center of the case  206 , but when the socket B is disposed in the vicinity of the center of the case  206 , electronic components  205 , . . . must be mounted on the case  206  avoiding and surrounding the socket B in the high-voltage pulse generator  100 . As a result, the wiring distance between the electronic components  205 , . . . is increased and a path through which pulses pass, that is, a large-current path, is elongated in the pulse generating section denoted by the letter P indicated in  FIG. 15 , thereby deteriorating the electrical characteristic. Since the high voltage of the secondary winding N 2  may leak to the electronic components  205  mounted on the vicinity of the high voltage part of the secondary winding N 2  of the pulse transformer PT, an additional insulating process should be performed to the electronic components  205 , thereby increasing the manufacturing cost. 
     That is, in the conventional high-voltage pulse generator  100 , when the radius of rotation is decreased in response to the requirement for decrease in size of the lighting apparatus, deterioration in performance due to the deterioration of electrical characteristic or increase in manufacturing cost may be newly caused. 
     DISCLOSURE OF INVENTION 
     Technical Problem 
     The present invention is contrived to solve the above-mentioned problems. An object of the invention is to provide a high-voltage pulse generator with a reduced radius of rotation and improved performance, and a lighting apparatus and a vehicle having the high-voltage pulse generator. 
     Technical Solution 
     According to a first aspect of the present invention, there is provided a high-voltage pulse generator comprising a pulse transformer in which a primary winding and a secondary winding are wound on a rod-shaped core, a discharge lamp connector which is made of an insulating material in a tube shape having an opened front surface out and which has therein an electrode electrically connected to a high voltage part of the secondary winding, and a pulse generating capacitor and a discharge switch electrically connected to the primary winding of the pulse transformer, wherein the discharge lamp connector is disposed so that the center thereof is located in a line passing through a substantial center in an axis direction of the pulse transformer and perpendicular to the axis direction, and the capacitor and the discharge switch are disposed to be opposed to the high voltage part of the secondary winding with the discharge lamp connector therebetween. 
     According to the configuration of the first aspect described above, since the discharge lamp connector is positioned in the line which passes through the substantial center in the axis direction of the pulse transformer and is perpendicular to the axis direction, the radius of rotation can be decreased. Since the pulse generating capacitor and the discharge switch are disposed to be opposed to the high voltage part of the secondary winding with the discharge lamp connector therebetween and to be spaced apart from the high voltage part of the secondary winding, it is possible to prevent the high voltage inducted by the secondary winding N 2  from leaking to the low-voltage circuit such as the pulse generating capacitor or the discharge switch. Since the capacitor and the discharge switch are together disposed on the same side, the path through which the pulse passes is shortened. Consequently, it is possible to enhance the performance. 
     In the high-voltage pulse generator according to a second aspect of the invention, in addition to the configuration of the first aspect, an input portion for connection to a power line of an external power source is be disposed to be opposed to the pulse transformer with the discharge lamp connector therebetween. 
     According to the configuration of the second aspect, the pulse transformer which is a heavy component is disposed with good lateral balance when the input portion is disposed to face the low side. Consequently, it is possible to obtain a high-voltage pulse generator with good weight balance. 
     In the high-voltage pulse generator according to a third aspect of the invention, in addition to the configuration of the first aspect, an input portion for connection to a power line of an external power source is disposed to be opposed to the discharge lamp connector transformer with the pulse transformer therebetween. 
     According to the configuration of the third aspect, the pulse transformer which is a heavy component is disposed on the lower side with good lateral balance when the input portion is disposed to face the low side. Consequently, it is possible to obtain a high-voltage pulse generator with better weight balance in comparison with the second aspect. 
     In the high-voltage pulse generator according to a fourth aspect of the invention, in addition to the configuration of any one of the first to third aspects, the discharge lamp connector has a socket into which a cap of a discharge lamp is detachably fitted. 
     According to the configuration of the fourth aspect, the discharge lamp can be attached detachably. 
     In the high-voltage pulse generator according to a fifth aspect of the invention, in addition to the configuration of any one of the first to third aspects a discharge lamp is fifitted to the discharge lamp connector. 
     According to the configuration of the fifth aspect, since the discharge lamp is directly fixed, the elements such as a cap and a socket can be omitted. Consequently, it is possible to utilize large-scaled electronic components or to accomplish the decrease in size of the high-voltage pulse generator. 
     According to a sixth aspect of the invention, there is provided a lighting apparatus having the high-voltage pulse generator of any one of the first to fifth aspects. 
     According to the configuration of the sixth aspect, since the lighting apparatus has the high-voltage pulse generator with a small radius of rotation and an improved electrical characteristic, it is possible to provide a lighting apparatus with a small size and high performance. 
     According to a seventh aspect of the invention, there is provided a vehicle having the lighting apparatus of the sixth aspect 
     According to the configuration of the seventh aspect, since the vehicle has the lighting apparatus with a small size and high performance, it is possible to increase the size of a cabin and thus to provide a vehicle with improved comfort. 
    
    
     
       DESCRIPTION OF DRAWINGS 
         FIG. 1(   a ) is a rear view partially illustrating a high-voltage pulse generator according to a first embodiment of the present invention,  FIG. 1(   b ) is a lateral view partially illustrating the high-voltage pulse generator, and  FIG. 1(   c ) is a front view partially illustrating the high-voltage pulse generator. 
         FIG. 2  is an assembly diagram illustrating a transformer section according to the first embodiment of the present invention. 
         FIG. 3  is an assembly diagram illustrating the high-voltage pulse generator according to the first embodiment of the present invention. 
         FIG. 4(   a ) is a perspective view illustrating the high-voltage pulse generator according to the first embodiment of the present invention and  FIG. 4(   b ) is another perspective view thereof. 
         FIG. 5(   a ) is a cross-sectional view schematically illustrating a lighting apparatus employing the high-voltage pulse generator according to the first embodiment of the present invention and  FIG. 5(   b ) is a perspective view partially illustrating a vehicle having the lighting apparatus according to the first embodiment of the present invention. 
         FIG. 6  is a rear view partially illustrating another example of the high-voltage pulse generator according to the first embodiment of the present invention. 
         FIG. 7(   a ) is a perspective view partially illustrating the high-voltage pulse generator according to the first embodiment of the present invention before filling it with resin and  FIG. 7(   b ) is a perspective view partially illustrating the high-voltage pulse generator according to the first embodiment of the present invention after filling it with resin. 
         FIG. 8(   a ) is a rear view partially illustrating a high-voltage pulse generator according to a second embodiment of the present invention,  FIG. 8(   b ) is a lateral view partially illustrating the high-voltage pulse generator, and  FIG. 8(   c ) is a front view partially illustrating the high-voltage pulse generator. 
         FIG. 9(   a ) is a rear view partially illustrating another high-voltage pulse generator according to the second embodiment of the present invention,  FIG. 9(   b ) is a lateral view partially illustrating the high-voltage pulse generator, and  FIG. 9(   c ) is a front view partially illustrating the high-voltage pulse generator. 
         FIG. 10(   a ) is a rear view partially illustrating a high-voltage pulse generator according to a third embodiment of the present invention,  FIG. 10(   b ) is a lateral view partially illustrating the high-voltage pulse generator, and  FIG. 10(   c ) is a front view partially illustrating the high-voltage pulse generator. 
         FIG. 11  is an assembly diagram illustrating the high-voltage pulse generator. 
         FIG. 12  is a perspective view illustrating the high-voltage pulse generator. 
         FIG. 13  is a perspective view illustrating a conventional high-voltage pulse generator. 
         FIG. 14  is an assembly diagram illustrating the conventional high-voltage pulse generator. 
         FIG. 15  is a circuit diagram illustrating the conventional high-voltage pulse generator. 
         FIG. 16  is a cross-sectional view schematically illustrating a lighting apparatus employing the conventional high-voltage generator. 
     
    
    
     BEST MODE 
     Hereinafter, exemplary embodiments of the present invention will be described with reference to  FIGS. 1 to 12 . 
     First Embodiment 
     A high-voltage pulse generator  1  according to a first embodiment of the present invention (see  FIG. 4 ), as shown in  FIGS. 1(   a ) to  1 ( c ), includes: a transformer section TB having a pulse transformer PT in which a primary winding N 1  and a secondary winding N 2  are wound on a core  2  and a discharge lamp connector  31  which is made of an insulating material in a tube shape having a bottom and an opened front surface (front side in  FIG. 1(   c )) and which has therein an inner electrode (center electrode) OUT 1  electrically connected to a high voltage part of the secondary winding N 2  in the low part  31   a ; and a circuit section CB having a pulse generating capacitor C and a discharge switch SG electrically connected to the primary winding N 1  of the pulse transformer PT, and a wiring board  5  mounted with them, wherein a n internal apparatus block  10  including the transformer section TB and the circuit section CB is received in a shield case  7  along with a case body  6  which is a front cover of the internal apparatus block  10 . 
     Since the circuit configuration of the high-voltage pulse generator  1  according to the first embodiment is similar to the conventional configuration shown in  FIG. 15 , like elements are denoted by like reference numerals and the description thereof is omitted. So long as a specific limitation is not mentioned, the side protruding from the paper in  FIG. 1(   c ) is referred to as a front side of the high-voltage pulse generator  1 , the upper side in  FIG. 1C  is referred to as an upper side of the high-voltage pulse generator  1 , the lower side in  FIG. 1C  is referred to as a lower side of the high-voltage pulse generator  1 , the right side in  FIG. 1C  is referred to as a right side of the high-voltage pulse generator  1 , the left side in  FIG. 1(   c ) is referred to as a left side of the high-voltage pulse generator  1 , and the side entering the paper in  FIG. 1C  is referred to as a rear side of the high-voltage pulse generator  1 . 
     The transformer section TB, as shown in  FIG. 2 , includes a pulse transformer PT and a resin case  3  for receiving the pulse transformer PT. The discharge lamp connector  31  is integrally formed with the resin case  3 . 
     The pulse transformer PT, as shown in  FIG. 2 , includes a core  2 , a secondary winding N 2  wound on the core  2 , a coil bobbin  20  fitted to surround the secondary winding N 2  which is wound on the core  2  and disposed on the low voltage part of the secondary winding N 2 , and a primary winding N 1  wound on the coil bobbin  20  which is fitted to surround the core  2 . 
     Here, the core  2  is made of synthetic resin containing about 80 wt % of magnetic particles such as ferrite particles, for example, Ni—Zn ferrite particles and is formed in a rod shape having an elliptical section. The secondary winding N 2  is a rectangular wire having a thin foil shape and is wound on the core  2  by the use of an edgewise winding method (a direction of winding the rectangular wire to be opposed to each other in the width direction). 
     The coil bobbin  20  is, for example, a resin molded member made of an insulating resin and integrally includes a cylinder-shaped hosting drum  20   a  on which the primary winding N 1  is wound and flanges  20   b  and  20   b  formed at both ends of the host drum  20   a . A hole  20   c  is axially formed in the coil bobbin  20  and the size of the hole  20   c  is set so as to allow the core  2  on which the secondary winding N 2  is wound to pass through the hole  20   c.    
     The resin case  3  is made of, for example, synthetic resin having a predetermined insulating property, for example, such as liquid crystal polymer and as shown in  FIG. 1(   a ), integrally includes a reception part  30  for receiving the pulse transformer PT and the discharge lamp connector  31 . Here, the discharge lamp connector  31  is disposed on one side (on the right side in  FIG. 1(   a )) of the reception part  30  so that the center O thereof is located in a center line CL 1  passing through a substantial center in an axis direction (a direction parallel to a center line CL 2 ) of the pulse transformer PT received in the reception part  30  and being perpendicular to the axis direction. 
     The reception part  30  is formed in a rectangular hexahedron shape of which the rear side (the front side in  FIG. 1A ) is opened and has a space for receiving the pulse transformer PT therein. When the pulse transformer PT is received in the reception part  30 , the longitudinal center of the reception part  30  and the axial center of the pulse transformer PT are designed substantially to coincide with each other. 
     The discharge lamp connector  31  is formed in a tube shape having a bottom and an opened front surface (the front side in  FIG. 1(   c )). More specifically speaking, the discharge lamp connector  31  integrally includes a circular bottom  31   a  and a tube-shaped portion  31   b  protruding forwardly from the circumferential edge of the bottom  31   a  and has an inner diameter approximately equal to the outer diameter of a cap E of an HID lamp DL. A pair of rectangular holes  32  and  32  is formed through the bottom  31   a  and a rectangular recessed portion  33  is formed in the outer circumferential surface of the tube-shaped portion  31   b . In addition, a tube-shaped inner wall  31   c  integrally protrudes from the bottom  31   a  so as to surround the pair of holes  32  and  32 , thereby guaranteeing an insulation distance between the inner electrode OUT 1  and the outer electrode OUT 2  with the inner wall  31   c.    
     On the other hand, an inner-electrode terminal  40  which is the inner electrode OUT 1 , an outer-electrode terminal  41  which is the outer electrode OUT 2 , and a first connection terminal  42  and a second connection terminal  43  for electrically connecting the pulse transformer PT to the wiring board  5  are disposed in the resin case  3 . 
     The inner-electrode terminal  40  integrally has a pair of electrode terminal portions  40   a  and  40   a  opposed to each other, a caulking portion  40   b  to which the high-voltage end of the secondary wiring N 2  is caulked and fixed, an approximately L-shaped connection  40   c  integrally connecting the base ends of the electrode terminals  40   a  and  40   a  to the caulking portion  40   b , and is formed by bending a conductive metal plate. 
     The outer-electrode terminal  41  integrally has a horizontally longitudinal flat portion  41   a , a pair of electrode terminal portions  41   b  and  41   b  extending forwardly from the front end of the flat portion  41   a , and a circuit terminal  41   c  extending laterally from the rear end of the flat portion  41   a  and is formed by bending a conductive metal plate. 
     The first connection terminal  42  integrally has a primary-winding caulking portion  42   a  to which an end of the primary winding N 1  is fixed in a caulking manner, a secondary-winding caulking portion  42   b  to which a low-voltage end of the secondary winding N 2  is fixed in a caulking manner, and a longitudinal terminal portion  42   c  which has both caulking portions  42   a  and  42   b  at one end thereof and of which the other end is connected to the wiring board  5 , and is formed by bending a conductive metal plate. 
     The second connection terminal  43  integrally has a primary-winding caulking portion  43   a  to which the other end of the primary winding N 1  is fixed in a caulking manner and a longitudinal terminal portion  43   b  which has the caulking portion  43   a  at one end thereof and of which the other end is connected to the wiring board  5 , and is formed by bending a conductive metal plate. 
     The terminals  40  to  43  are attached to the resin case  3  as follows. 
     The inner-electrode terminal  40  is attached to the rear surface of the resin case  3 , in the state that a pair of electrode terminal portions  40   a  and  40   a  are protruded forwardly from the pair of holes  32  and  32  formed through the bottom  31   a  of the discharge lamp connector  31  and the caulking portion  40   b  is disposed on the high voltage side (the lower end in  FIG. 1(   a )) of the secondary winding N 2  of the pulse transformer PT received in the reception part  30 . 
     The outer-electrode terminal  41  is attached to the resin case  3  by inserting the flat portion  41   a  into the recessed portion  33  of the tube-shaped portion  31   b  of the discharge lamp connector  31  in the state that the electrode terminal portions  41   b  and  41   b  are placed in the tube-shaped portion  31   b.    
     The first connection terminal  42  is attached to the resin case  3 , in the state that both caulking portions  42   a  and  42   b  are disposed on the low voltage side (the upper side in  FIG. 1(   a )) of the secondary winding N 2  of the pulse transformer PT received in the reception part  30  and the terminal portion  42   c  is protruded toward the discharge lamp connector  31  (to the right side in  FIG. 1(   a )) from the reception part  30 . 
     The second connection terminal  43  is attached to the resin case  3  to be parallel to the first connection terminal  42 , in the state that the caulking portion  43   a  is disposed on the low voltage side (the upper side in  FIG. 1(   a )) of the secondary winding N 2  of the pulse transformer PT received in the reception part  30  and the terminal portion  43   b  is protruded toward the discharge lamp connector  31  (to the right side in  FIG. 1(   a )) from the reception part  30 . 
     In this way, the terminals  40  to  42  are attached to the resin case  3  and the discharge lamp connector  31  to which the inner-electrode terminal  40  and the outer-electrode terminal  41  are attached serves as the socket B to which the HID lamp DL is detachably fitted. As shown in  FIG. 1A , the pulse transformer PT is received in the resin case  3  in the stat that the high voltage side of the secondary winding N 2  faces the downside and the coil bobbin  20  becomes close to two connection terminals  42  and  43 . Both ends of the primary winding N 1  wound on the coil bobbin  20  are fixed to the caulking portion  42   a  of the first connection terminal  42  and the caulking portion  43   a  of the second connection terminal  43  in the caulking manner, respectively. The low-voltage end of the secondary winding N 2  wound on the core  2  is fixed to the caulking portion  42   b  of the first connection terminal  42  in the caulking manner, and the high-voltage end is fixed to the caulking portion  40   b  of the inner-electrode terminal  40  in the caulking manner. Thereafter, the reception part  30  is filled with insulating resin  8  such as epoxy resin to improve the insulating property of the pulse transformer PT. 
     In this way, the transformer section TB is constructed and the circuit section CB is then described. In the circuit diagram shown in  FIG. 15 , the circuit section SB includes circuit components other than the primary winding N 1  of the pulse transformer PT in the low-voltage side circuit LV, that is, the pulse generating capacitor PT, the discharge switch SG, the surge absorber ZNR such as a varistor, the charge discharging resistor R, power supply terminals  44  to  46  which are formed in a band shape out of a conductive metal plate and to which the connection lines L 1  to L 3  of the harness H are connected, and the wiring board  5  on which the components are mounted. 
     In the wiring board  5 , a printed pattern (not shown) for constituting the circuit shown in  FIG. 15  is formed on a rectangular insulating substrate  50 . Here, as shown in  FIG. 1(   a ), the length in the longitudinal direction of the insulating substrate  50  is set substantially equal to the length in the longitudinal direction (the vertical direction in  FIG. 1(   a )) of the reception part  30  of the resin case  3  and the length in the lateral direction is set substantially equal to the thickness (the vertical size in  FIG. 3)  of the reception part  30  of the resin case  3 . In  FIG. 1(   b ) and  FIG. 10(   b ), the wiring board  5  is omitted. 
     On one surface of the wiring substrate  5 , the capacitor C is mounted at one end (the upper end in  FIG. 1A ) in the longitudinal direction and the discharge switch SG is mounted at the end in the longitudinal direction of the wiring board  5  to be close to the capacitor C and closer to the end. The surge absorber ZNR is mounted at the center in the longitudinal direction of the wiring board  5 . The resistor R and the electrode terminals  44  to  46  are mounted at the other end in the longitudinal direction of the wiring board  5 . 
     In the circuit section CB having the above-mentioned structure, as shown in  FIG. 1(   a ), one surface of the wiring board  5  mounted with the circuit components such as the capacitor C is opposed to the reception part  30  with the discharge lamp connector  31  of the resin case  3  therebetween and one end in the longitudinal direction at which the capacitor C and the discharge switch SG are mounted is directed to the low voltage side of the secondary winding N 2  of the pulse transformer PT. Accordingly, the pulse generating capacitor C and the discharge switch SG are disposed to be opposed to the high voltage area HF including the high voltage side of the secondary winding N 2  of the pulse transformer PT and the inner-electrode terminal  40  with the discharge lamp connector therebetween. At this time, the wiring board  5  is disposed in a projection plane of the reception part  30  to the wiring board  5 . The circuit section CB is attached to the transformer section TB by mounting the outer-electrode terminal  41  and the connection terminals  42  and  43  on the wiring board  5  by soldering or the like. Accordingly, an inner apparatus block  10  having the circuit configuration shown in  FIG. 15  is obtained and the inner apparatus block  10  is formed in the square shape in which the vertical size and the horizontal size are substantially equal to each other, as shown in  FIG. 1(   c ). 
     The inner apparatus block  10  obtained in this way is received in a shield case  7  for shielding the inner apparatus block  10  from electronic noises along with a case body  6  having a bayonet structure for fixing the HID lamp DL. Accordingly, the high-voltage pulse generator  1  shown in  FIGS. 4A and 4B  is completed. 
     As shown in  FIG. 3 , the case body  6  is formed in a box shape made of insulating resin in which the rear surface is opened and then is attached to the front side of the inner apparatus block  10 . A circular hole  6   a  for exposing the discharge lamp connector  31  of the inner apparatus block  10  to the outside is formed through the front surface of the case body  6 , and a circular circumferential wall  6   b  surrounding the hole  6   a  is protruded forwardly from the circumferential edge of the hole  6   a . Notched portions  6   c  for fixing HID lamp DL are formed in the circumferential wall  6   b  to divide the circumferential wall  6   b  into four portions in the circumferential direction. Each notched portion  6   c  has a so-called bayonet structure having a substantial L shape including a guide portion  6   d  extending forwardly and backwardly of which the front end is opened and a fixing portion  6   e  formed to extend in the circumferential direction from the rear end of the guide portion  6   d  and to be perpendicular to the forward and backward direction, so as to correspond to each fixing pin (not shown) of the HID lamp DL. The circumferential wall  6   b  is shown in  FIGS. 1 ,  6 ,  8 , and  9 , for the purpose of convenience of explanation. 
     As shown in  FIG. 3 , the shield case  7  includes a rear (back) shield  70  and a front shield  71  which are made of metal. The rear shield  70  is formed in an angular tube shape having a square-shaped bottom and a box-shaped connector case  70   a  of which the inside communicates with the rear shield  70  is integrally formed at the center of the lower surface which the power supply terminals  44  to  46  of the inner apparatus block  10  are disposed close to. The front surface of the connector case  70   a  is opened and the harness H is inserted into the rear shield  70  through the connector case  70   a  from the opened front surface. In this way, after the harness H is inserted and connected to the power supply terminals  44  to  46  of the inner apparatus block  10 , the connector case  70   a  is filled with insulating resin or the like. 
     The front shield  71  is formed in a box shape of which the rear surface is opened, a circular hole  71   a  for externally protruding the circumferential wall  6   b  of the case body  6  is formed in the front surface, and a cylindrical tube-shaped portion  71   b  along the outer circumferential surface of the circumferential wall  6   b  of the case body  6 , that is, having an inner diameter substantially equal to the outer diameter of the circumferential wall  6   b , is integrally protruded from the circumferential edge of the hole  71   a.    
     Here, the inner apparatus block  10  is received in the shield case  7  along with the case body  6  as follows. First, the inner apparatus block  10  is received in the rear shield  70  in the state that the socket B is directed forward and the connection lines L 1  to L 3  of the harness H inserted into the rear shield  70  through the connector case  70   a  are connected to the power supply terminals  44  to  46  of the inner apparatus block  10 , respectively. Accordingly, the connector case  70   a  serves as an input portion for connection to power supply lines of an external power source. At this time, the connection lines L 1  to L 3  are drawn to the high voltage side of the secondary winding N 2  of the pulse transformer PT. Thereafter, the case body  6  is attached to the front side of the inner apparatus block  10  and the front shield  71  is attached to the rear shield  70  in the state that the circumferential wall  6   b  of the case body  6  is directed to the outside through the hole  71   a.    
     In this way, the inner apparatus block  10  is received in the shield case  7  along with the case body  6 , thereby completing the high-voltage pulse generator  1  shown in  FIGS. 4(   a ) and  4 ( b ). Since the operation of the high-voltage pulse generator  1  is substantially similar to that of the conventional example, description thereof is omitted. 
     According to the high-voltage pulse generator  1  according to the first embodiment described above, as shown in  FIGS. 1(   a ) to  1 ( c ), since the discharge lamp connector  31  constituting the socket B is disposed in the center line CL 1  which passes through the center in the axis direction (the direction of the center line CL 2 ) of the pulse transformer PT and is perpendicular to the axis direction, the distance between the center O of the discharge lamp connector  31  and the end of the resin case  3 , that is, the radius of rotation, can be reduced smaller than that of the conventional example shown in  FIG. 14 . In addition, as shown in  FIG. 5(   a ), when the high-voltage pulse generator is used in the vehicle headlight apparatus  300 ′ and the size of the lamp inserting hole  310   a  is reduced to correspond to the high-voltage pulse generator  1 , the installation position of the HID lamp DL in the lamp housing  310  is not inclined toward a side of the lamp inserting hole  310   a  thanks to the discharge lamp connector  31  having been disposed as described above, thereby not deteriorating the workability of fitting the HID lamp DL. 
     As shown in  FIG. 1(   a ), since the pulse generating capacitor C and the discharge switch SG are disposed to be opposed to the high voltage area HF including the high voltage side of the secondary winding N 2  of the pulse transformer PT and the inner-electrode terminal  40  with the discharge lamp connector  31  therebetween (that is, disposed on the opposite side about the center line CL 1 ) and is spaced apart from the high voltage area HF, it is possible to prevent the high voltage from leaking to the low-voltage side circuit LV such as the pulse generating capacitor C and the discharge switch SG without performing an additional insulating process to the capacitor C and the discharge switch SG. Since the circuit components (such as the surge absorber ZNR and the resistor R) of the low-voltage side circuit LV are not disposed in the high voltage area HF, the same advantages can be obtained. 
     In addition, by together mounting the pulse generating capacitor C and the discharge switch SG at one end in the longitudinal direction of the wiring board  5  and directing the end in the longitudinal direction of the wiring board  5  to the low voltage side of the secondary winding N 2  of the pulse transformer PT, the capacitor C and the discharge switch SG are disposed close to the primary winding N 1  of the pulse transformer PT. Accordingly, the pulse generating section P is wired as short as possible. That is, since the wiring length of the pulse generating section P, that is, the path through which the pulses pass (large-current path), is reduced, it is possible to improve the electrical characteristic of the high-voltage pulse generator  1 , thereby enhancing the performance of the high-voltage pulse generator  1 . 
     As described above, the high-voltage pulse generator  1  according to the first embodiment can be used in a vehicle headlight apparatus  300 ′ shown in  FIG. 5(   a ). By using the high-voltage pulse generator  1  according to the first embodiment, the lamp inserting hole  310   a  can be reduced without deteriorating the workability of fitting the HID lamp and the electrical characteristic of the high-voltage pulse generator, unlike the conventional example. Accordingly, it is possible to obtain a vehicle headlight apparatus  300 ′ with a small size and high performance. 
     Therefore, according to the vehicle headlight apparatus  300 ′ employing the high-voltage pulse generator  1  according to the first embodiment, the decrease in size can be accomplished without problem. Accordingly, when the vehicle headlight apparatus  300 ′ is used in a vehicle  400  shown in  FIG. 5(   b ), the whole size of the vehicle  400  can be decreased or the size of the cabin (sitting room) can be increased by a reduced space for the vehicle headlight apparatus  300 ′, thereby improving a comfort at the time of riding. 
     The high-voltage pulse generator  1  according to the first embodiment can be used in a vehicle assistant lighting apparatus or other lighting apparatus, in addition to the vehicle headlight apparatus  300 ′ described above. 
     On the other hand, in the high-voltage pulse generator  1 , as shown in  FIG. 1A , the inner-electrode terminal  40  is exposed externally, but in view of safety, a circumferential wall  34  surrounding the inner-electrode terminal may be formed in the resin case  3 , as shown in  FIGS. 6 and 7 . 
     For example, as shown in  FIG. 7(   a ), the circumferential wall  34  integrally protrudes from the rear surface of the bottom  31   a  of the discharge lamp connector  31  so as to surround the inner-electrode terminal  40 ′ and the circumferential wall  34  communicates with the reception part  30 . 
     In the examples shown in  FIGS. 6 and 7 , the inner-electrode terminal  40 ′, the first connection terminal  42 ′, and the second connection terminal  43 ′ have the same functions as the inner-electrode terminal  40 , the first connection terminal  42 , and the second connection terminal  43  shown in  FIG. 1 , but are different in structure therefrom. The different structures are described below. The inner-electrode terminal  40 ′ integrally includes a  -shaped’ terminal portion  40   a ′ having a pair of electrode terminals (not shown) and a  -shaped’ caulking portion  40   b ′ in which the high voltage end of the secondary winding N 2  is fixed to one end thereof in the caulking manner and the terminal portion  40   a ′ is fixed to the other end in the caulking manner. The terminal portion  40   a ′ and the caulking portion  40   b ′ are formed, respectively, by bending conductive metal plates. 
     The first connection terminal  42 ′ integrally includes a secondary-winding caulking portion  42   a ′ to which the low voltage end of the secondary winding N 2  is fixed in the caulking manner and a longitudinal terminal portion  42   b ′ of which one end has a caulking portion  42   a ′ and the other end is mounted on the wiring board  5 . The first connection terminal  42 ′ is formed by bending a conductive metal plate and one end of the primary winding N 1  is fixed to one end of the first connection terminal  42 ′ by soldering or the like. 
     The second connection terminal  43 ′ is formed in a longitudinal shape out of a conductive metal plate. The other end of the primary winding N 1  is fixed to one end of the second connection terminal  43 ′ by soldering or the like and the other end of the second connection terminal  43 ′ is mounted on the wiring board  5 . 
     The pulse transformer PT is received in the resin case  3  having the circumferential wall  34 , the inner-electrode terminal  40 ′, and the connection terminals  42 ′ and  43 ′ in the state that the high voltage side of the secondary winding N 2  is directed to the lower side and the coil bobbin  20  becomes close to both connection terminals  42 ′ and  43 ′, as shown in  FIG. 7(   a ). Both ends of the primary winding N 1  wound on the coil bobbin  20  is fixed to the ends of the connection terminals  42 ′ and  43 ′, respectively. The low-voltage end of the secondary winding N 2  wound on the core  2  is fixed to the caulking portion  42   a ′ of the first connection terminal  42 ′ in the caulking manner and the high voltage end is fixed to the caulking portion  40   b ′ of the inner-electrode terminal  40 ′ in the caulking manner. Thereafter, the insulating resin  8  such as epoxy resin is filled in the reception part  30  and the inside of the circumferential wall  34 , as shown in  FIG. 7(   b ). 
     Therefore, according to the high-voltage pulse generator  1  shown in  FIGS. 6 and 7 , it is possible to improve the insulating property of the inner-electrode terminal  40 ′ which is supplied with a high-voltage. 
     Although the connecting lines L 1  to L 3  of the harness H are directly connected to the power supply terminals  44  to  46  of the wiring board  5  in the high-voltage pulse generator, a connector may be constructed so that the harness H is detachably connected to the connector case by the use of pin-shaped terminals instead of the connecting lines L 1  to L 3 . This is true of second and third embodiments to be described later. 
     Mode for Invention 
     Second Embodiment 
     When the high-voltage pulse generator is used in the vehicle headlight apparatus  300 ′ shown in  FIG. 5(   a ), the connector case  70   a  of the high-voltage pulse generator  1  from which the harness H is drawn may be disposed at the lower side so as not to elongate the harness H for connection to the inverter  330 . 
     However, in the high-voltage pulse generator  1  according to the first embodiment, the connector case  70   a  which serves as the input portion for connection to the power line (harness) of an external power source is disposed on the high voltage side of the secondary winding N 2  of the pulse transformer PT, as shown in  FIG. 3 . Accordingly, as shown in  FIG. 5A , when the high-voltage pulse generator is fitted to the vehicle headlight apparatus  300 ′, the pulse transformer PT which is a relatively heavy component is disposed at the right side. For this reason, the lateral weight balance of the high-voltage pulse generator  1  becomes much worse and the high-voltage pulse generator  1  tends to rotate about the HID lamp DL so as to move the pulse transformer PT, thereby imposing an unnecessary load to the HID lamp DL. 
     Therefore, in the high-voltage pulse generator according to the second embodiment, as shown in  FIG. 8(   c ), the power supply terminals  44  to  46  are disposed on the rear side (the left side in  FIG. 8(   b )) of the center in the longitudinal direction of the wiring board  5  on one surface of the wiring board  5  opposed to the resin case  3  and when the inner apparatus block  11  is received in the shield case  7 , the connector case  70   a  of the shield case  7  is opposed to the pulse transformer PT with the discharge lamp connector  31  therebetween (that is, the connector case  70   a  is located on the opposite side of the pulse transformer PT about the center line CL 2 ). At this time, the connection lines L 1  to L 3  of the harness H connected to the power supply lines  44  to  46  are drawn toward the wiring board  5  (to the lower side in  FIG. 8A)  along the center line CL 1  and then are drawn out to the outside, as shown in  FIGS. 8(   a ) to  8 ( c ). Since the other configuration is substantially similar to that of the first embodiment, like elements are denoted by like reference numerals and description thereof is omitted. 
     Therefore, according to the high-voltage pulse generator according to the second embodiment, when the high-voltage pulse generator is disposed with the connector case  70   a  directed downward, as shown in  FIGS. 8(   a ) to  8 ( c ), the pulse transformer PT which is a heavy component is located above the high-voltage pulse generator  1  in the state that the axis direction is parallel to the lateral direction. Accordingly, the pulse transformer PT is disposed with excellent lateral balance, thereby obtaining a high-voltage pulse generator with excellent weight balance. 
     On the other hand, the high-voltage pulse generator according to the second embodiment is not limited to that shown in  FIG. 8 , but the connector case  70   a  may be opposed to the discharge lamp connector  31  with the pulse transformer PT (that is, the connector case  70   a  may be located on the same side as the pulse transformer PT about the center line CL 2 ), when the inner apparatus block  11  is received in the shield case  7 . At this time, the connection lines L 1  to L 3  of the harness H connected to the power supply terminals  44  to  46  are drawn out toward the pulse transformer PT (to the lower side in  FIG. 9(   a )) along the center line CL 1  and are drawn to the outside from the connector case  70   a , as shown in  FIGS. 9(   a ) to  9 ( c ). 
     Therefore, according to the high-voltage pulse generator shown in  FIG. 9 , when the high-voltage pulse generator is disposed with the connector case  70   a  directed downward, as shown in  FIGS. 9(   a ) to  9 ( c ), the pulse transformer PT which is a heavy component is located below the high-voltage pulse generator  1  in the state that the axis direction is parallel to the lateral direction. Accordingly, the pulse transformer PT is disposed with excellent lateral balance, thereby obtaining a high-voltage pulse generator with excellent weight balance. Unlike the high-voltage pulse generator shown in  FIG. 8 , since the pulse transformer PT is disposed on the lower side, the weight balance can be further improved in comparison with that shown in  FIG. 8 . 
     Although it has been shown in  FIGS. 8 and 9  that a part of the connection lines L 1  to L 3  are included in the high voltage area HF, the connection lines L 1  to L 3  may be detoured so as not to enter the high voltage HF. 
     Third Embodiment 
     In the high-voltage pulse generator  1  according to the first embodiment, the socket B which is detachably fitted with the HID lamp DL is constructed by the discharge lamp connector  31  to cope with the HID lamp DL having the cap E. However, a high-voltage pulse generator  1 ′ according to a third embodiment is designed to cope with an HID lamp (hereinafter, referred to as a burner)  9  not having a cap and includes a discharge lamp connection  35  to which the burner  9  is fixed by welding or the like. The elements similar to those of the high-voltage pulse generator  1  according to the first embodiment are denoted by the same reference numerals and description thereof is omitted. 
     First, the burner  9  is described. The burner  9  may be a mercury lamp or a metal halide lamp and is a so-called cantilever type discharge lamp including a light emitting tube  90 , a pair of electrodes  91  and  92  disposed apart from each other in the light emitting tube  90 , and a cylindrical tube-shaped support  93  to which the rear end of the light emitting tube  90 . 
     The light emitting tube  90  may be made of quartz glass and a spherical discharging space in which mercury, halogen gas, or inert gas is enclosed is formed at the center thereof. The electrodes  91  and  92  are formed in a longitudinal rod shape out of, for example, tungsten and are fitted to the light emitting tube  90  so that one end thereof is protruded into the light emitting tube  90  and the other end is protruded externally from the light emitting tube  90 . Both electrodes  91  and  92  are disposed so that the ends are spaced apart from each other with a predetermined gap in the discharging space of the light emitting tube  90 . The electrodes  91  and  92  and the light emitting tube  90  are air-tightly sealed. 
     The support  93  includes a substantially cylinder-shaped base  93   a  in which the light emitting tube  90  is fixed to the front end and the other end of the electrode  91  protruded from the light emitting tube  90  is inserted into the rear end to be protruded from the rear end, and a ring-shaped flange portion  93   b  surrounding the front end of the base  93   a . The electrode  92  protruded from the light emitting tube  90  is drawn out to be protruded from the rear end of the base  93   a  through the base  93   a  and the flange portion  93   b  and is protected by a protection tube  94 . 
     Similarly to the known discharge lamp, in the burner  9  having the above-mentioned structure, for example, when a predetermined voltage (breakdown voltage) is applied across the pair of electrodes  91  and  92 , dielectric breakdown occurs in the discharging space of the light emitting tube  90  to start discharge, the sealed mercury is vaporized, and thus light is emitted by plasma discharge of the high-pressure mercury gas. 
     Next, the high-voltage pulse generator  1 ′ according to the third embodiment is described with reference to  FIGS. 10 to 12 . The high-voltage pulse generator  1 ′ according to the third embodiment (see  FIG. 12 ), as shown in  FIGS. 10A to 10C , includes a transformer section TB having a pulse transformer PT and a discharge lamp connector  35  which is formed in a tube shape having an opened front surface (the front side in  FIG. 10C ) out of an insulating material and which has an inner-electrode terminal (not shown) electrically connected to the high voltage side of the secondary winding N 2  therein, and a circuit section CB. An inner apparatus block  12  including the transformer section TB and the circuit section CB is received in a protection case  60  and a shield case  72 . The circuit configuration of the high-voltage pulse generator  1 ′ according to the third embodiment is similar to that according to the first embodiment. 
     As shown in  FIG. 10 , the transformer section TB includes a pulse transformer PT and a resin case  3 ′ for receiving the pulse transformer PT. The discharge lamp connector  35  is integrally formed in the resin case  3 ′. 
     The resin case  3 ′ is made of synthetic resin having a predetermined insulating property such as liquid crystal polymer and as shown in  FIG. 10A , integrally includes a reception part  30  for receiving the pulse transformer PT and the discharge lamp connector  35 . Here, the discharge lamp connector  35  is disposed on one side (on the right side in  FIG. 10(   a )) of the reception part  30  so that the center O′ thereof is located in a center line CL 1  passing through a substantial center in an axis direction (a direction parallel to a center line CL 2 ) of the pulse transformer PT received in the reception part  30  and being perpendicular to the axis direction. 
     The discharge lamp connector  35  is formed in a cylindrical tube shape and as shown in  FIG. 10(   a ), the reception part  30  communicates with the inside the discharge lamp connector  35  at the rear end thereof. The discharge lamp connector  35  has an inner diameter substantially equal to the outer diameter of the base  93   a  of the burner  9  and the burner can be fixed to the discharge lamp connector  35  by inserting the base  93   a  of the burner  9  into the discharge lamp connector  35 . 
     On the other hand, the resin case  3 ′ is provided with an inner-electrode terminal (not shown) electrically connected to the electrodes  91  and  92  of the burner  9  by soldering (welding) or the like, outer-electrode terminals  41 ′, and connection terminals  42  and  43 . 
     The inner-electrode terminal is formed in a band shape out of a conductive metal plate and is disposed in the resin case  3 ′ so that a portion welded to the electrode  91  of the burner  9  is protruded into the discharge lamp connector  35  so as to electrically connect the electrode  91  of the burner  9  to the high voltage end of the secondary winding N 2 . 
     The outer-electrode terminal  41 ′ is formed in a band shape out of a conductive metal plate and is disposed in the resin case  3 ′ so that one end thereof is buried in the discharge lamp connector  35  and the other end is protruded from the discharge lamp connector  35  to the wiring board  5  so as to electrically connect the electrode  92  of the burner  9  to the wiring board  5 . 
     The resin case  3 ′ has the above-mentioned configuration, and the burner  9  is fixed to the discharge lamp connector  35  of the resin case  3 ′ by inserting the base  93   a  of the burner  9  into the discharge lamp connector  35  of the resin case  3 ′ and electrically connecting the electrodes  91  and  92  of the burner  9  to the inner-electrode terminal and the outer-electrode terminal  41 ′ by soldering or the like. 
     Similarly to the first embodiment, the pulse transformer PT is received in the resin case  3 ′ in the stat that the high voltage side of the secondary winding N 2  faces the downside and the coil bobbin  20  becomes close to two connection terminals  42  and  43 . Both ends of the primary winding N 1  wound on the coil bobbin  20  are fixed to the caulking portion  42   a  of the first connection terminal  42  and the caulking portion  43   a  of the second connection terminal  43  in the caulking manner, respectively. The low-voltage end of the secondary winding N 2  wound on the core  2  is fixed to the caulking portion  42   b  of the first connection terminal  42  in the caulking manner, and the high-voltage end is fixed to the caulking portion  40   b  of the inner-electrode terminal  40  in the caulking manner. Thereafter, the discharge lamp connector  35  and the reception part  30  are filled with insulating resin  8  such as epoxy resin to improve the insulating property of the pulse transformer PT. 
     The transformer section TB is constructed as described above, and the circuit section CB is attached to the transformer section TB, similarly to the first embodiment. 
     That is, In the circuit section CB, as shown in  FIG. 10(   a ), one surface of the wiring board  5  mounted with the circuit components such as the capacitor C is opposed to the reception part  30  with the discharge lamp connector  31  of the resin case  3 ′ therebetween and one end in the longitudinal direction at which the capacitor C and the discharge switch SG are mounted is directed to the low voltage side of the secondary winding N 2  of the pulse transformer PT. Accordingly, the pulse generating capacitor C and the discharge switch SG are disposed to be opposed to the high voltage area HF including the high voltage side of the secondary winding N 2  of the pulse transformer PT and the inner-electrode terminal with the discharge lamp connector therebetween. When the wiring board  5  is disposed in the resin case  3 ′, the wiring board  5  is disposed in a projection plane of the reception part  30  to the wiring board  5 . The circuit section CB is attached to the transformer section TB, by mounting the outer-electrode terminal  41 ′ and the connection terminals  42  and  43  on the wiring board  5  by the use of soldering or the like, thereby obtaining an inner apparatus block  10  having the circuit configuration shown in  FIG. 15 . 
     The inner apparatus block  12  obtained in this way is received in a protection case  60  for mechanically and electrically protecting the inner apparatus block  12  and a shield case  72  for shielding the inner apparatus block  12  from electronic noises. Accordingly, the high-voltage pulse generator  1 ′ shown in  FIG. 12  is completed. 
     As shown in  FIG. 11 , the protection case  60  includes a case cover  61  formed in a box shape of which the front surface is opened out of insulating resin and a case body  62  formed in a box shape of which the rear surface is opened out of insulating resin and which is attached to the case cover  61  from the front side. An angular tube-shaped connector case  61   a  of which the top and bottom surfaces are opened to draw out the connection lines L 1  to L 3  connected to the inner apparatus block  12  is disposed at the substantial center of the lower surface of the case cover  61 . On the other hand, a circular hole  62   a  having a size enough to allow the burner  9  to pass (in other words, having an inner diameter substantially equal to the outer diameter of the flange portion  93   b  of the burner  9 ) is formed in the front surface of the case body  62 . A rectangular notched portion  62   b  into which a part of the front side of the connector case  61  is inserted is formed in the bottom surface of the case body  62 . The protection case  60  may be filled with insulating resin such as epoxy so as to improve the insulating property at the time of receiving the inner apparatus block  12  in the protection case  60 . 
     As shown in  FIG. 11 , the shield case  72  includes a rear (back) shield  73  and a front shield  74  which are made of metal. The rear shield  73  is formed in a box shape of which the front surface is opened, a rectangular notched portion  73   a  is formed in the lower side corresponding to the connector case  61   a  of the protection case  60 , and a ‘ -shaped’ connector shield cover  73   b  covering the rear surface of the connector case  60   a  is integrally protruded from the circumferential edge of the notched portion  73   a . The front shield  74  is formed in a box shape of which the rear surface is opened, and a circular hole  74   a  having a size enough to allow the burner  9  to pass (in other words, having an inner diameter substantially equal to the outer diameter of the flange portions  93   b  of the burner  9 ) is formed in the front surface. A rectangular notched portion (not shown) is formed in the lower side corresponding to the connector case  61   a  of the protection case  60  and the  -shaped’ connector shield cover  74   b  covering the front side of the connector case  60   a  is integrally protruded from the circumferential edge of the notched portion. 
     The inner apparatus block  12  is received in the protection case  60  and the shield case  72  as follows. First, the inner apparatus block  12  to which the burner  9  is attached in advance is received in the case cover  61  in the state that the burner is directed forward, and the connection lines L 1  to L 3  are connected to the power supply terminals  44  to  46  of the inner apparatus block  12  through the connector case  61   a , respectively. Accordingly, the connector case  61   a  serves as an input portion for connection to power supply lines of an external power source. Thereafter, the case body  62  is attached to the front side of the inner apparatus block  12 , the rear shield  73  and the front shield  74  is attached to the protection case in which the inner apparatus block  12  is received, and then the protection case  60  is received in the shield case  72 . 
     In this way, the inner apparatus block  12  is received in the protection case  60  and the shield case  72 , thereby completing the high-voltage pulse generator  1 ′ shown in  FIG. 12 . Since the operation of the high-voltage pulse generator  1 ′ is substantially similar to that of the conventional example, description thereof is omitted. 
     According to the high-voltage pulse generator  1 ′ according to the third embodiment described above, as shown in  FIGS. 10A to 10C , since the discharge lamp connector  35  to which the burner  9  is fitted is disposed in the center line CL 1  which passes through the center in the axis direction of the pulse transformer PT and is perpendicular to the axis direction, the distance between the center O′ of the discharge lamp connector  35  and the end of the resin case  3 ′, that is, the radius of rotation, can be reduced smaller than that of the conventional example shown in  FIG. 14 . In addition, as shown in  FIG. 5A , when the high-voltage pulse generator is used in the vehicle headlight apparatus  300 ′ and the size of the lamp inserting hole  310   a  is reduced to correspond to the high-voltage pulse generator  1 ′, the installation position of the burner  9  in the lamp housing  310  is not inclined toward a side of the lamp inserting hole  310   a  thanks to the discharge lamp connector  31  having been disposed as described above, thereby not deteriorating the fitting workability. 
     As shown in  FIG. 10(   a ), since the pulse generating capacitor C and the discharge switch SG are disposed to be opposed to the high voltage area HF including the high voltage side of the secondary winding N 2  of the pulse transformer PT and the inner-electrode terminal with the discharge lamp connector  35  therebetween (that is, disposed on the opposite side about the center line CL 1 ) and is spaced apart from the high voltage area HF, it is possible to prevent the high voltage from leaking to the low-voltage side circuit LV such as the pulse generating capacitor C and the discharge switch SG without performing an additional insulating process to the capacitor C and the discharge switch SG. Since the circuit components (such as the surge absorber ZNR and the resistor R) of the low-voltage side circuit LV are not disposed in the high voltage area HF, the same advantages can be obtained. 
     In addition, by together mounting the pulse generating capacitor C and the discharge switch SG at one end in the longitudinal direction of the wiring board  5  and directing the end in the longitudinal direction of the wiring board  5  to the low voltage side of the secondary winding N 2  of the pulse transformer PT, the capacitor C and the discharge switch SG are disposed close to the primary winding N 1  of the pulse transformer PT. Accordingly, the pulse generating section P is wired as short as possible. That is, since the wiring length of the pulse generating section P, that is, the path through which the pulses pass (large-current path), is reduced, it is possible to improve the electrical characteristic of the high-voltage pulse generator  1 ′, thereby enhancing the performance of the high-voltage pulse generator  1 ′. 
     In the high-voltage pulse generator  1 ′ according to the third embodiment, since the discharge lamp (burner) not having a cap is used and the discharge lamp is fixed to the discharge lamp connector  35 , the cap and the socket can be omitted in comparison with the first embodiment. Accordingly, it is possible to utilize a large-scaled electronic component as the pulse generating capacitor C or the like and to accomplish the decrease in size of the high-voltage pulse generator. 
     The high-voltage pulse generator  1  according to the third embodiment can be used in a vehicle assistant lighting apparatus or other lighting apparatus, in addition to the vehicle headlight apparatus  300 ′ described above. 
     INDUSTRIAL APPLICABILITY 
     According to the present invention, it is possible to reduce the radius of rotation, to prevent a high voltage generated in the secondary winding from leaking to the low-voltage part circuit such as the high-voltage generating capacitor and the discharge switch, and to improve performance.