JP2002270010A - Discharge lamp device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a discharge lamp device causing no trouble such as UV deterioration of an insulating plug of synthetic resin, and giving no bad influence to the appearance of the lamp, by blocking irradiation of UV from the restricted region of an arc tube. SOLUTION: In this discharge lamp device, a shroud glass 20 is integrated with an arc tube 11 by welding so as to surround a discharge part 12 to form an arc tube body 10, and the rear extended part 14b of the arc tube, which extends toward the rear of the shroud glass 20, is inserted and held in the opening part 32 of an insulating plug 30 of synthetic resin. A UV shielding film 102 is formed on the outer surface of the rear extended part 14b of the arc tube, a UV component in the light leaked from the rear extended part 14b is cut off, and a quantity of ultra violet rays to which a resin layer in the opening part 32 is exposed is reduced. The UV shielding film 102 is placed in the opening part 32 and is not visible through a front lens. Therefore, there is little possibility that the appearance of the lamp looks poor.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a discharge lamp device in which an arc tube extends in front of a synthetic resin insulating plug, and in particular, a shroud glass is welded and integrated to the arc tube to form a discharge portion on the shroud glass. The present invention relates to a discharge lamp device including an arc tube main body having an enclosed structure, wherein a rear extension of an arc tube extending rearward of the shroud glass is inserted and held in a front opening of a synthetic resin insulating plug.

[0002]

2. Description of the Related Art Since a discharge portion contains ultraviolet rays in a wavelength range harmful to the human body and lamp components (synthetic resin and metal), the conventional arc tube main body 2 includes:
As shown in FIG. 10, a cylindrical shroud glass 2b having a UV-cutting action is welded and integrated to the arc tube 2a, and the discharge portion 2a1 is surrounded by the shroud glass 2b, so that the arc tube 2a exits from the arc tube main body. It is configured such that ultraviolet rays contained in the emitted light are reduced.

[0003] As a conventional discharge lamp device,
A rear extension 2a2 of the arc tube extending behind the shroud glass 2b is inserted into the front opening 1a of the synthetic resin insulating plug (insulating base) 1 and is fixed to the front surface of the insulating plug 1. The rear end side of the arc tube 2 (the rear end of the shroud glass 2b) by the fixed jig 3 made of
Are fixedly supported, and the distal end side of the arc tube main body 2 is supported by a metal lead support 4 extending forward from the insulating plug 1.

Reference numeral 6 denotes a light distribution control light-shielding film provided on the outer surface of the shroud glass 2b, which blocks a part of the light going to the effective reflection surface 8a of the reflector 8 to form a clear clear cut line. It is for forming.

[0005]

However, in the reflection type headlamp using the above-described conventional discharge lamp device as a light source, the effective reflection surface 8a of the reflector 8 becomes cloudy.

[0006] As a result of investigations by the inventors, it was presumed that the UV component contained in light leakage from the arc tube main body 2 was the cause. That is, as shown by the arrow in FIG. 10, a part of the light emission of the discharge part 2a1 of the arc tube leaks from the rear extension part 2a2 of the arc tube and irradiates into the front opening 1a of the insulating plug 1. The light leakage contains ultraviolet rays in a wavelength range harmful to the synthetic resin, and the insulating plug (PPS resin) is deteriorated by receiving the ultraviolet rays or generates a sulfur-based gas. It is estimated that the effective reflection surface 8a is clouded or clouded.

Further, as a prior art for solving such a problem, there is Japanese Patent Application Laid-Open No. 2001-23427. This is because the light-irradiation control light-shielding film provided on the shroud glass is extended to the root portion on the rear end side of the shroud glass (outer tube), so that the UV irradiation amount to the concave portion of the insulating plug made of synthetic resin is provided. And a series of problems such as deterioration of the resin due to UV.

However, in the above-mentioned prior art, a light-shielding film for controlling light distribution, which is expensive due to a requirement for heat resistance, is provided so as to be extended to the rear end side of the shroud glass (outer tube). It is even more expensive. Further, in order to form a light-shielding film for controlling light distribution, baking is performed at a high temperature of, for example, 900 ° C., and drying is performed. The problem is that the time required for the operation increases and the operating cost increases.

Further, since the light-shielding film for light distribution control is generally black and is provided up to the root portion on the rear end side of the shroud glass (outer tube), the enlarged light distribution control light is transmitted through the front lens. The light-shielding film is seen through black, and the appearance is poor. In particular, in the recent lamp industry, there is a tendency that the light distribution is controlled by the reflector and the light distribution control step is not provided on the front lens. The appearance is very bad.

Therefore, as shown in FIG. 11, the inventors have found that only the rear extension A of the arc tube has a rear end B of the shroud glass facing the front opening 1a of the insulating plug.
Only the band-shaped region C between the fixing holder 3 and the light distribution controlling light-shielding film 6 and only the region D below the light distribution controlling light-shielding film 6 and corresponding to the vicinity of the valve insertion hole are A to D. An experiment was carried out to form a UV light-shielding film over the entire region and to confirm the effectiveness with respect to the lighting time (the effectiveness of the effective reflection surface 8a of the reflector 8 such that no trouble such as white turbidity occurs). The result was as shown in the figure.

That is, when a UV light-shielding film is formed in all the regions A to D, it is of course effective. However, only the rear extension A of the arc tube or the front opening 1 of the insulating plug 1 is effective.
It was also confirmed that a UV light-shielding film was formed only on the rear end B of the shroud glass facing a.

The present invention has been made in view of the above-mentioned problems of the prior art, and has been made based on the above-mentioned knowledge of the present inventors, and an object thereof is to irradiate UV from a limited area of an arc tube main body. An object of the present invention is to provide a discharge lamp device in which a problem such as UV deterioration does not occur in a synthetic resin insulating plug and that does not adversely affect the appearance of a lamp.

[0013]

In order to achieve the above object, in a discharge lamp device according to the present invention, a cylindrical shroud glass is welded and integrated with an arc tube so as to surround a discharge portion. In a discharge lamp device in which a tube body is configured and a rear extension of an arc tube extending behind the shroud glass is inserted and held in a front opening of a synthetic resin insulating plug, UV on outer surface of extension
A light-shielding film was formed. (Function) As a UV light shielding film, a ZnO film, a TiO ₂ film,
There is a multi-layer vapor deposition film, acrylic vapor deposition film, etc., and light leaking from the rear extension of the arc tube is converted to light with a low UV component when the UV component is cut when passing through the UV light shielding film. It is led into the front opening of the insulating plug.

The rear extension of the arc tube on which the UV light shielding film is formed is inserted and held in the front opening of the insulating plug, and the UV light shielding film cannot be seen through the front lens.

According to a second aspect of the present invention, in the discharge lamp device according to the first aspect, the front side of the insulating plug penetrates the shroud glass between the peripheral edge of the front side opening of the insulating plug and the rear end of the shroud glass. A light-blocking member that blocks light directed toward the inside of the opening is interposed. A metal fixing holder fixed to the front surface of the insulating plug and fixedly supporting the rear end of the shroud glass can also be configured to also serve as the light shielding member. (Function) Light (light including a UV component) that passes through the rear end of the shroud glass and enters the front opening of the insulating plug is interposed between the periphery of the front opening of the insulating plug and the rear end of the shroud glass. And the light does not reach the front opening of the insulating plug.

The fixing holder fixed to the insulating plug and fixedly supporting the rear end of the shroud glass also functions as a cover (light shielding member) for hiding the UV light shielding film.

According to a third aspect of the present invention, in the discharge lamp device according to the first aspect, a cylindrical light blocking member for preventing UV deterioration is provided along an inner peripheral surface of the opening on the front side of the insulating plug. Configured. (Effect) Light that passes through the rear end of the shroud glass and travels into the front opening of the insulating plug (light containing UV components) is provided on the surface of the inner peripheral surface of the front opening of the insulating plug to prevent UV deterioration. And does not reach the resin layer on the back side of the light-shielding member.

According to a fourth aspect of the present invention, in the discharge lamp device according to the first aspect, the insulating plug passes through the shroud glass between the peripheral edge of the front opening and the rear end of the shroud glass. A light-blocking member for blocking light traveling into the front opening is interposed, and UV light is applied along the inner peripheral surface of the front opening of the synthetic resin insulating plug.
It is configured such that a cylindrical light shielding member for preventing deterioration is provided. (Function) Light (light including a UV component) that passes through the rear end of the shroud glass and enters the front opening of the insulating plug is interposed between the periphery of the front opening of the insulating plug and the rear end of the shroud glass. And the light does not reach the front opening of the insulating plug. Furthermore, even if light (light containing UV components) leaks into the opening on the front side of the insulating plug without being fully shielded by the light shielding member, a cylindrical light shielding member provided along the inner peripheral surface of the opening for preventing UV deterioration. Because it is shaded by
Light emission (light including UV components) of the arc tube does not reach the resin layer on the back side of the light shielding member.

In the discharge lamp device according to the fifth aspect, a cylindrical shroud glass is welded and integrated with the arc tube so as to surround the discharge portion, thereby forming an arc tube main body. In a discharge lamp device in which a rear extension of an extending arc tube is inserted and held in a front opening of a synthetic resin insulating plug, a rear extension of the arc tube or / and a front extension of the insulating plug. A non-metallic cylindrical light-shielding shade having a UV-cutting action is applied to the rear end of the shroud glass facing the above. (Operation) In the form in which the light-shielding shade is attached to the rear extension of the arc tube, light containing a UV component does not leak from the rear extension of the arc tube into the opening. Further, in a mode in which the light-shielding shade is attached to the rear end of the shroud glass, light containing a UV component does not leak from the rear end of the shroud glass into the opening. Further, in a configuration in which a light-shielding shade is applied to the rearward extension of the arc tube and the rear end of the shroud glass, light containing UV components leaks into the opening from the rearward extension of the arc tube and the rear end of the shroud glass. Absent.

As the cylindrical light-shielding shade, a heat-resistant inorganic material having a UV-cutting action, such as a ceramic sleeve or soft glass, is desirable, and can be easily formed by sintering or molding. Can be attached.

The non-metallic cylindrical light-shielding shade is safe even when used in an insulating plug where a high voltage is generated, without the risk of dielectric breakdown. That is, a lead wire that is a current path is led out from the rear extension of the arc tube,
If the cylindrical light-shielding shade attached to the rear extension portion is made of metal, there is a possibility that insulation breakdown such as discharge between the lead wire and the cylindrical light-shielding shade may occur. With the light-shielding shade, there is no possibility that insulation breakdown will occur.

The rearward extension of the arc tube to which the cylindrical light-shielding shade is attached and the rear end of the shroud glass are inserted and held in the front opening of the insulating plug, and the light-shielding shade cannot be seen through the front lens.

In the discharge lamp device according to the present invention, a cylindrical shroud glass is welded and integrated with the arc tube so as to surround the discharge portion, thereby forming an arc tube main body. In a discharge lamp device in which a rear extension of an extending arc tube is inserted and held in a front opening of a synthetic resin insulating plug, an outer surface of the shroud glass is provided with a light distribution controlling light-shielding film, A UV light shielding film having a composition different from that of the light distribution controlling light shielding film is provided on the rear end of the shroud glass facing the rear extension of the arc tube and / or the front opening of the insulating plug. (Effect) Light leaking from the rear end of the shroud glass facing the rear extension of the arc tube or the front opening of the insulating plug is reduced to light with a low UV component when the UV component is cut when transmitting through the UV light shielding film. As a result, it is guided into the opening on the front side of the insulating plug made of synthetic resin.

In order to form a clear clear cut line, the light distribution controlling light-shielding film is required to have a light-shielding characteristic of a visible light component, and is provided near the discharge portion of the arc tube and is exposed to a high temperature. Is required. On the other hand, UV
The light-shielding film is required to have a light-shielding property of a UV component, and is provided at a rear-extending portion of the arc tube away from the discharge portion and at the rear end of the shroud glass, so that the heat-shielding film required for the light distribution control light-shielding film is required. Sex is not required. For this reason, by using a UV light-shielding film having a composition different from the composition of the light distribution control light-shielding film and optimal for the UV cut characteristics, the UV light leaking from the rearwardly extending portion of the arc tube or the rear end of the shroud glass is used.
The components are effectively cut.

The rearwardly extending portion and the rear end of the shroud glass of the arc tube on which the UV light shielding film is formed are inserted and held in the front opening of the insulating plug, and the UV light shielding film cannot be seen through the front lens.

[0026]

Next, embodiments of the present invention will be described based on examples.

FIGS. 1 to 5 show a first embodiment of the present invention. FIG. 1 is a perspective view of a discharge lamp device according to a first embodiment of the present invention, and FIG. FIG. 3 is a side view of the discharge lamp device, FIG. 4 is an exploded perspective view of a support member for fixing and holding the rear end of the shroud glass, and FIG. 5 is a cross-sectional view showing a UV light shielding film forming region in the arc tube body. It is.

In these figures, reference numeral 30 denotes a lamp-side connector C2, into which a power-supply-side connector C1 (see FIG. 3) can be inserted and detached, is integrally provided at the rear end thereof, and a reflector 100 of a headlamp for a vehicle is fitted with a bulb. Hole 102
An insulated plug made of PPS resin is provided on the outer periphery of a focal ring 34 engaged with (see FIG. 3). A metal lead support 36 extending forward from the plug 30 is provided in front of the insulated plug 30. The metal support member 50 fixed to the front surface of the plug 30 allows the arc tube body 1
0 is fixedly supported to form a discharge lamp device.

That is, the lead wire 18a extending from the front end of the arc tube main body 10 is fixed to the bent front end of the lead support 36 extending from the insulating plug 30 by spot welding.
The rear end portion of the base member 50 is held by a metal supporting member 50 including a base plate 51, a slide plate 61, and an arc tube holding band 71 fixed to the front surface of the insulating plug 30.

The arc tube body 10 is connected to the electrode 1
A cylindrical ultraviolet shielding shroud glass 20 is welded (sealed) and integrated with an arc tube 11 having a sealed glass sphere 12 opposed to 5a, 15b.
2 has a structure in which a shroud glass 20 surrounds and seals. Reference symbol L is a discharge axis connecting the electrodes 15a and 15b.

The arc tube 11 is formed by processing a circular pipe-shaped quartz glass tube, and includes a spheroid-shaped closed glass sphere 12 sandwiched between pinch seal portions 13a and 13b having a rectangular cross section at predetermined positions in the longitudinal direction. With the formed structure, a rare gas for starting, mercury, and a metal halide (for example, a sodium-scandium-based luminescent material) are contained in the glass bulb 12.
Is enclosed. A rectangular molybdenum foil 16a, 16b is sealed to the pinch seal portions 13a, 13b. On one side of the molybdenum foils 16a, 16b, a tungsten electrode 15a opposed to the inside of the closed glass bulb 12 is provided. , 15b on the other side, the arc tube 11
Lead wires 18a and 18b extending to the outside are respectively connected. Pinch seal part 13 of arc tube 11
a, 13b to the closed glass bulb 12 are surrounded and sealed by the shroud glass 20, and a circular pipe-shaped rearwardly extending portion 14b (see FIG. 2) which is a non-pinch sealed portion of the arc tube 11 is shroud glass 20. Extends behind.

The shroud glass 20 is made of TiO 2, C
It is made of quartz glass doped with eO2 and having a light-shielding effect on ultraviolet rays, and reliably cuts off ultraviolet rays in a predetermined wavelength range that is harmful to the human body from light emitted from the sealed glass bulb 12 as a discharge part. Further, the inside of the shroud glass 20 is made to be in a vacuum state or a state in which an inert gas is filled, and performs an adiabatic action against the radiation of heat from the sealed glass bulb 12 which is a discharge part, so that the lamp characteristics are changed in the external environment. Designed to be unaffected.

On the front side of the insulating plug 30, there is formed a cylindrical inner cylindrical portion 31 provided with an opening 32 through which the rear extending portion 14b of the arc tube 11 can be inserted and accommodated.
Bridge portion 3 having lead support insertion hole 35a formed
A cylindrical outer cylindrical portion 33 around which a focus ring 34 is provided is formed around the inner cylindrical portion 31 except for the portion 5. And
The lead support 36 is inserted into the lead support insertion hole 35a.
Is inserted, and a lead support 3 is inserted through the insulating sleeve 36a.
6 protrudes rearward from a tapered hole 35 c (see FIG. 2) that opens on the back side of the insulating plug 30, and is used for lead support of a belt-type terminal 44 provided at the rear end of the insulating plug 30. It is inserted into the hole 45a and is laser welded.

A cylindrical metal base plate 51 is tightly fixed to the front edge of the inner cylindrical portion 31. The base plate 51 is integrated with the insulating plug 30 by exposing the disc-shaped base 52 (see FIG. 4) by insert molding in which the base plate 51 is inserted into a mold.

The disk-shaped base 52 of the base plate 51 integrated with the insulating plug 30 has a metal slide plate 61 and a metal arc tube grip band 7.
1 and a metal vertical holding member 60 for vertically holding the shroud glass 20 of the arc tube 10 is fixedly joined thereto so that the discharge axis L of the arc tube body 10 coincides with the central axis of the focusing ring 34. Are located in

That is, as shown in FIG. 4, the arc tube gripping band 71 constituting the vertical holding member 60 is formed in a rectangular shape bent into an L-shaped cross section at a mating portion with both ends of a band-like band main body 72. Ear pieces 74 are formed, and the ear pieces 74 of the band main body 72 wound around the shroud glass 20 of the arc tube main body 10 are attached to each other, and these are spot-welded, so that the holding band 71 is attached to the shroud glass 20.
Can be wound and fixed. Reference numeral 73 denotes a bent portion provided at two locations in the longitudinal direction of the band main body 72. The band main body 72 expands and contracts by elastically deforming the bent portion 73, thereby winding the band main body 72 around the shroud glass 20. Can be fixed times. Reference numeral 75 indicates a spot weld.

As shown in FIG. 4, the metal slide plate 61 constituting the vertical holding member 60 is formed in a donut disk shape whose base 62 is aligned with the base 52 of the base plate 51. Are provided with four tongue-like holding pieces 64 in the form of a leaf spring that are cut and raised to stand up at equal intervals in the circumferential direction. The outer periphery of the arc tube gripping band 71 wound and fixed on the shroud glass 20 of the arc tube main body 10 is clamped by the tongue-like clamping piece 64, and the tongue-like clamping piece 64 is laser welded to the gripping band 71. The arc tube 1
The zero discharge axis L is perpendicular to the joint surface of the slide plate 61 with the base plate 51 (the bottom surface of the donut disk-shaped base portion 62 of the slide plate 61) and is located at a predetermined distance from the bottom surface of the base portion 62. Thus, the arc tube main body 10 is integrated with the slide plate 61. Reference numerals 65 and 66 indicate laser welds.

A cylindrical outer cylindrical portion 42 extending rearward and a cylindrical boss 43 extending rearward in the outer cylindrical portion 42 are formed at the rear end of the insulating plug 30. On the outer periphery of the base of the portion 42, a lamp side connector C2 is provided.
Cylindrical terminal 44 constituting the negative terminal of
Are fixed and integrated, and the boss 43 has a cap-type terminal 47 constituting a positive terminal of the lamp-side connector.
Are integrated. Reference numeral 48 denotes a lead wire engaging hole provided at the top of the cap type terminal 47, which is led out from the rear end side of the arc tube 10 and has an opening 3 of the insulating plug 30.
2 and the lead wire 18 passing through the lead wire insertion hole 43b
b is engaged with the engagement hole 48 and is laser-welded.

Further, as shown in FIG. 5, a rear extension 1 of the arc tube extending rearward of the shroud glass 20.
4b, a UV light shielding film 100 is formed on the outer surface and the rear end face 20a of the shroud glass.
And light leakage from the rear end face 20a of the shroud glass (FIG. 5)
The UV component in the dashed arrow is cut off so that the resin layer on the inner peripheral surface of the opening 32 of the insulating plug is not deteriorated by UV. In other words, light leaking from the rear extension portion 14b of the arc tube and the rear end surface 20a of the shroud glass is transmitted through the UV light shielding film 100 so that the UV component is cut off, and the light having less UV component is irradiated into the opening 32. Is done. For this reason, the amount of ultraviolet rays exposed to the inner peripheral surface (resin layer) of the opening 32 is reduced, and UV deterioration of the resin layer is suppressed.

Light leakage from the outer periphery of the rear end of the shroud glass 20 (solid arrow in FIG. 5) is also guided into the opening 32.
The metal base plate 51 provided at the entrance periphery of the opening 32 functions as a cylindrical light-blocking member for preventing UV deterioration, so that light leaks from the outer periphery of the rear end of the shroud glass 20 to approach the entrance in the opening 32. Of the resin layer does not deteriorate by UV.

Further, the light passing through the rear end side of the shroud glass 20 and traveling toward the opening 32 is provided so as to close the opening 32, and the metal grip band 71 and the metal slide plate 61 function as a light shielding member. Accordingly, the intrusion into the opening 32 is prevented, so that the resin layer in the opening 32 is not deteriorated by UV due to the light that has entered through the opening 32.

In the above embodiment, the rear end portion 20b of the arc tube is used to extend the rear end face 20 of the shroud glass.
a, the UV light shielding film 100 is formed on the outer peripheral surface of the rear end of the shroud glass 20 facing the opening 32.
UV components in light leaked from the outer periphery of the rear end are also cut, so that problems such as UV deterioration of the resin layer in the opening 32 are further improved.

FIG. 6 is a sectional view showing a discharge lamp device according to a second embodiment of the present invention.

In the second embodiment, a non-metallic cylindrical light-shielding shade 102 having a UV-cutting action is attached from the rear extension 14b of the arc tube to the rear end of the shroud glass facing the opening 32. Then, the structure is such that light containing a UV component does not leak into the opening 32 from the rear extension portion 14b of the arc tube and the rear end of the shroud glass 20.

That is, the rear extending portion 14b of the arc tube
Light leakage from the rear end of the shroud glass 20 or the shroud glass 20 is prevented, so that the amount of ultraviolet rays exposed to the opening 32 of the insulating plug is reduced and the insulating plug 30 is not deteriorated.

A non-metallic conical light-shielding shade 104 for preventing UV deterioration is provided on the bottom surface of the opening 32 so that the distal end surface 14a of the rear extension portion 14b of the arc tube is provided.
Measures are taken to protect the resin layer against light leakage containing UV components leaking from b1.

The light-shielding shades 102 and 104 are made of a heat-resistant inorganic or organic material having a UV-cutting effect, such as ceramics, glass (UV absorbing glass, soft glass, or opaque glass), PC resin, or acrylic resin. It is desirable.

The other parts are the same as those of the above-described embodiment, and the same reference numerals are given, and the duplicate description will be omitted.

Further, the light-shielding shades 102 and 104 are made of a non-metallic material, so that they can be used safely in the insulating plug 30 where a high voltage is generated, without any risk of dielectric breakdown. That is, a lead wire 18b, which is a current path, is led out from the rear extension 14b of the arc tube, and the lead wire 18b is inserted through the middle hole of the light-shielding shade 104. If the light-shielding shades 102 and 104 are made of metal, dielectric breakdown such as discharge between the lead wire 18b and the light-shielding shades 102 and 104 may occur. There is no possibility that this will occur.

The light-shielding shades 102 and 104 are located in the opening 32 and are hidden by the slide plate 61, so that they cannot be seen at all through the front lens and do not impair the appearance of the lamp.

The cylindrical light-shielding shade 102 is connected to the shroud glass 20 from the rear extension 14b of the arc tube.
It is configured to cover the area to the rear end,
As shown by reference numerals 102A and 102B in FIGS. 7A and 7B, a structure that covers only the rear extension 14b of the arc tube or only the rear end of the shroud glass 20 may be used.

FIG. 8 is a sectional view showing a discharge lamp device according to a third embodiment of the present invention.

In this embodiment, the surface region of the rear extension 14b of the arc tube denoted by reference numeral 105 is subjected to a grain or frost surface treatment. For this reason, the light leakage (see the dashed arrow in FIG. 8) containing the UV component emitted from the rear extension portion 14b is diffused, and the energy of the UV component applied to the resin layer on the inner peripheral surface of the opening 32 is weakened, Therefore, the influence of UV deterioration is small.

Also, with respect to light leakage (see the solid arrow in FIG. 8) containing UV components from the rear end portion (the bottom surface and the outer peripheral surface) of the shroud glass, a metal base plate 51 functioning as a UV deterioration preventing member is provided. This is supported by extending downward.

The other parts are the same as those of the above-described embodiment, and the same reference numerals are given, and the duplicated description is omitted. In order to prevent UV deterioration of the resin layer in the opening 32, it is desirable to extend the base plate 51 near the bottom of the opening 32, but it is not necessary to extend the base plate 51 to the lead 18 b exposed in the opening 32. There is a limit because the surface distance becomes short and there is a risk of dielectric breakdown.

FIG. 9 is a sectional view showing a discharge lamp device according to a fourth embodiment of the present invention.

A light distribution controlling light-shielding film 110 for forming a clear cut line is formed on the outer surface of the shroud glass 20, and the arc tube extends rearward from the rear end of the shroud glass 20 facing the opening 32. A UV light shielding film 112 having a composition different from that of the light distribution controlling light shielding film 110 is formed on the portion 14b.

Since the light distribution controlling light-shielding film 110 is provided near the discharge portion 12 of the arc tube and is exposed to a high temperature, heat resistance is required. On the other hand, the UV light shielding film 112
Although the light shielding property of the UV component is required, the light shielding film 1 for light distribution control is provided on the rear extension part 14b of the arc tube away from the discharge part 12 and on the rear end of the shroud glass.
10 is not required to be as heat resistant as required. Therefore, as the UV light shielding film 112, the light distribution controlling light shielding film 110 is used.
A UV light shielding film having a composition that is different from that of the above and is optimal for the UV cut characteristics with reduced heat resistance is used, and the UV component in the light leakage from the rear extension portion 14b of the arc tube and the rear end of the shroud glass 20 is used. Is effectively cut.

The rear extension 14b and the rear end of the shroud glass of the arc tube on which the UV light shielding film 112 is formed are inserted and held in the opening 32 of the insulating plug.
When the discharge lamp device of this embodiment is used as a light source for a headlamp (light source for forming a low beam), the UV light shielding film 112 does not show through the front lens and does not look bad at all. .

In the fourth embodiment, the UV light shielding film 112 is formed at the rear end of the shroud glass facing the rear extension 14b and the opening 32 of the arc tube. Even if the UV light shielding film 112 is formed only on one of the extending portion 14b and the rear end of the shroud glass, although it is slightly inferior to the case where both are formed, as shown in the experimental results in FIG. It must be effective in preventing UV degradation of the resin layer in 32.

[0061]

As is apparent from the above description, according to the discharge lamp device of the present invention, the UV component during the light leakage from the rear extension of the arc tube is cut, and the synthetic resin insulating plug is cut off. Problems such as deterioration of insulating plugs, especially PPS, because the amount of ultraviolet rays exposed to the front opening decreases.
Irradiation of ultraviolet rays to the insulating plug made of resin generates organic gas, and there is no problem that the organic gas causes clouding or cloudiness on the effective reflection surface of the lamp reflector.

Further, since the UV light shielding film cannot be seen through the front lens, the external appearance of the lamp is good.

According to the second aspect, in addition to cutting the UV component during the light leakage from the rearward extension of the arc tube, the light containing the UV component transmitted through the rear end of the shroud glass is also used for the insulation plug. Since it does not reach the front side opening, the amount of ultraviolet rays that the front side opening of the insulating plug made of synthetic resin receives further decreases, and there is no further possibility that a problem such as deterioration of the insulating plug occurs.

The UV in the opening on the front side of the insulating plug
Since the light-shielding film is securely hidden by the light-shielding member, the external appearance of the lamp is further improved.

According to the third aspect, in addition to cutting off the UV component during the light leakage from the rearward extension of the arc tube, the light containing the UV component transmitted through the rear end of the shroud glass is cylindrically shielded. Since the light is shielded by the member and does not reach the resin layer on the back side of the light-shielding member, there is no further possibility that a problem such as deterioration of the insulating plug occurs.

According to the discharge lamp device of the present invention, in addition to cutting the UV component during the light leakage from the rear extension portion of the arc tube, the light containing the UV component transmitted through the rear end of the shroud glass is removed. Is blocked by a light blocking member at the entrance of the front opening of the insulating plug, and further blocked by a cylindrical light blocking member for preventing UV deterioration provided along the opening. There is no danger that the amount of ultraviolet light that is exposed to the resin layer that constitutes the above will significantly decrease, and problems such as deterioration of the insulating plug will occur.

The UV in the opening on the front side of the insulating plug is
Since the light-shielding film is securely hidden by the light-shielding member, the external appearance of the lamp is further improved.

According to the fifth aspect, the U from the rearward extension of the arc tube and / or the rear end of the shroud glass.
Light leakage including the V component is prevented, and the amount of ultraviolet light that is exposed to the opening on the front side of the insulating plug is reduced, so that there is no problem such as deterioration of the insulating plug.

Further, since the cylindrical light-shielding shade attached to the rear extension of the arc tube is made of a non-metallic material, there is no danger of dielectric breakdown even when used in an insulating plug where a high voltage is generated. It is safe.

Further, since the cylindrical light-shielding shade in the front opening of the insulating plug cannot be seen through the front lens, the appearance of the lamp is good.

According to the sixth aspect, the UV component in the light leaking from the rear extension portion of the arc tube is cut, and the amount of the ultraviolet rays exposed to the front opening of the synthetic resin insulating plug is reduced. There is no defect such as deterioration. In particular, the UV light-shielding film formed on the rearward extension of the arc tube or the rear end of the shroud glass is more U-shaped than the light distribution control light-shielding film.
By using a composition having excellent V-cut characteristics, problems such as deterioration of the insulating plug are further improved.

The UV light shielding film formed on the rear extension of the arc tube or on the rear end of the shroud glass is made of a composition having a heat-resistant property that is lower than that of the light distribution control light shielding film. The cost itself is low, and
Since heat resistance is not required even when forming the V light-shielding film, it is simple in terms of equipment and work, and accordingly, a discharge lamp device can be provided at a low cost.

Further, since the UV light shielding film in the opening on the front side of the insulating plug cannot be seen through the front lens, the appearance of the lamp is good.

[Brief description of the drawings]

FIG. 1 is a perspective view of a discharge lamp device according to a first embodiment of the present invention.

FIG. 2 is a longitudinal sectional view of the discharge lamp device.

FIG. 3 is a side view of the discharge lamp device.

FIG. 4 is an exploded perspective view of a shroud glass rear end fixing and holding member.

FIG. 5 is a cross-sectional view showing a UV light shielding film formation region in the arc tube main body.

FIG. 6 is a sectional view of a discharge lamp device according to a second embodiment of the present invention.

FIG. 7A is a sectional view of a main part of a modified example of the second embodiment. (B) It is a principal part sectional view of another modification of the second embodiment.

FIG. 8 is a longitudinal sectional view of a discharge lamp device according to a third embodiment of the present invention.

FIG. 9 is a longitudinal sectional view of a discharge lamp device according to a fourth embodiment of the present invention.

FIG. 10 is a longitudinal sectional view of a conventional discharge lamp device.

FIG. 11 is a view showing a position where a UV light shielding film is formed on an arc tube main body used in an experiment.

FIG. 12 is a diagram showing experimental results.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 10 Arc tube main body 11 Arc tube 12 Closed glass bulb which is a discharge part 14b Back extension part of arc tube 15a, 15b Discharge electrode 18a, 18b Lead wire 20 Shroud glass for ultraviolet shielding 30 Synthetic resin insulating plug 32 Opening 36 Metal Lead support 50 Metal support member for fixing and holding the rear end of the shroud glass to the insulating plug 51 Metal base plate 61 Metal slide plate 71 Metal grip band L Discharge shaft 100, 112 UV light shielding film 102, 102A, 102B Nonmetal Shading shade 110 made of light distribution control

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Masaya Shito 500 Kitawaki, Shimizu-shi, Shizuoka Pref.

Claims (6)

[Claims] An arc tube main body is formed by welding and integrating a cylindrical shroud glass to an arc tube so as to surround a discharge portion, and a rearward extension of the arc tube extending rearward of the shroud glass. A discharge lamp device in which a portion is inserted and held in a front opening of a synthetic resin insulating plug, wherein a UV light shielding film is formed on an outer surface of a rearwardly extending portion of the arc tube. 2. A light-shielding member interposed between a peripheral edge of a front side opening of the insulating plug and a rear end of the shroud glass to block light passing through the shroud glass and entering the front side opening of the insulating plug. The discharge lamp device according to claim 1, wherein the discharge lamp device is provided. 3. The discharge lamp device according to claim 1, wherein a cylindrical light shielding member for preventing UV deterioration is provided along an inner peripheral surface of the front opening of the insulating plug. . 4. A light-shielding member interposed between the peripheral edge of the front side opening of the insulating plug and the rear end of the shroud glass to block light passing through the shroud glass toward the inside of the front side opening of the insulating plug. 2. The discharge lamp device according to claim 1, wherein a cylindrical light shielding member for preventing UV deterioration is provided along an inner peripheral surface of the front side opening of the synthetic resin insulating plug. 5. An arc tube main body is formed by welding and integrating a cylindrical shroud glass to an arc tube so as to surround a discharge portion, and a rearward extension of the arc tube extending rearward of the shroud glass. In a discharge lamp device in which a portion is inserted and held in a front opening of a synthetic resin insulating plug, a rear extension of the arc tube or / and a rear end of the shroud glass facing the front opening of the insulating plug. A discharge lamp device comprising a non-metallic cylindrical light-shielding shade having a UV cut action. 6. An arc tube in which a cylindrical shroud glass is welded and integrated with an arc tube so as to surround a discharge portion, and an arc tube rearward extension portion extending rearward of the shroud glass. In the discharge lamp device inserted and held in the front opening of the insulating plug made of synthetic resin, a light distribution control light-shielding film is provided on the outer surface of the shroud glass, and the rear extension of the arc tube or And / or a UV light shielding film having a composition different from that of the light distribution controlling light shielding film is provided at a rear end of the shroud glass facing the front opening of the insulating plug.