JP4586766B2 - Light source device - Google Patents

Description

  The present invention relates to a light source device including a concave reflecting mirror and a discharge lamp.

  The projection type projector device is required to irradiate an image with a uniform color rendering property to a rectangular screen, and an ultrahigh pressure discharge lamp is preferably used as a light source for this purpose. In such a discharge lamp, a large amount of mercury is enclosed in the arc tube, so that a high operating pressure can be achieved at the time of lighting, thereby suppressing the spread of the arc and realizing a large light output.

In an optical apparatus provided with such a high-pressure discharge lamp, it is required to further reduce the size as the projector apparatus to be mounted is reduced in size and space. From such a demand, not only the high-pressure discharge lamp but also the concave reflecting mirror to which the lamp is mounted is required to be miniaturized, and for this purpose, the base device mounted at the end of the sealing tube portion of the high-pressure discharge lamp, A light source device having a structure that excludes a ceramic base used to connect a high-pressure discharge lamp to a concave reflecting mirror has been widely used.
For example, Patent Document 1 discloses a light source device in which a concave reflecting mirror and a high-pressure discharge lamp are fixed with an adhesive.

FIG. 5 is a side sectional view showing a conventional example of the light source device for the projector device described above.
In the figure, the concave reflecting mirror 20 is specifically a concave and forms a light collecting space 21 and a front part that forms an opening at a front end (left end in the figure) 21a of the light collecting portion 21. A base body comprising an outer edge portion and a cylindrical neck portion 24 extending rearward in the optical axis direction following the rear end (right end in the drawing) 21b of the light collecting portion 21 is provided, and visible light is formed on the inner surface of the light collecting portion 21. The reflective layer 22 is formed. This concave reflecting mirror is made of borosilicate glass or the like.
The high-pressure discharge lamp 10 includes an arc tube portion 12 and sealed tube portions 13a and 13b connected to both ends of the arc tube portion 12. A predetermined amount of mercury, rare gas, halogen, etc. are enclosed in the arc tube portion 12. The electrode rods 14a and 14b connected to the electrodes E1 and E2 are welded to the metal foils 15a and 15b hermetically sealed in the sealing tube portions 13a and 13b to be external lead rods. It is connected and connected to 16a, 16b.
In the internal space of the concave reflecting mirror 20, the high pressure discharge lamp 10 is disposed substantially horizontally so that the tube axis of the high pressure discharge lamp 10 and the optical axis of the concave reflecting mirror 20 coincide with each other. The rear sealing tube portion 13b (the right end in the figure) is inserted into the cylindrical neck portion 24 of the base body 20a, and the adhesive 30 is filled over the entire area inside the cylindrical neck portion 24 to make the high-pressure discharge lamp 10 concave. The light source device is configured by being fixed to the reflecting mirror 20.

By adopting a configuration in which the high-pressure discharge lamp and the concave reflecting mirror are directly connected in this way, the length L of the cylindrical neck portion in the concave reflecting mirror is prevented from becoming long, and the light source device is miniaturized. .
JP 2004-342446 A

  However, in the above light source device, it has been found that there is a situation in which the high-pressure discharge lamp cannot be started from the beginning even though it is a new lamp that does not appear to be defective.

The reason for this will be described below with reference to the previous figure and FIG.
The adhesive 30 that bonds the concave reflecting mirror 20 and the high-pressure discharge lamp 10 is a material that has sufficient heat resistance and can achieve and maintain a strong connection since the high-pressure discharge lamp 20 becomes extremely hot. Specifically, an alkaline inorganic adhesive obtained by kneading an inorganic powder such as alumina or silica with an aqueous solution containing an alkali metal silicate is used. In particular, high adhesion and heat resistance can be realized by increasing the blending of alkali metals.

  However, when such a light source device passes through a hot and humid area during transportation and is exposed to a place where a lot of water vapor exists in the air, or accidentally exposed to rainwater during transportation outdoors, There arises a situation in which alkali metal ions in the components of the adhesive 30 leak into moisture adhering to the surface of the lamp 10. As a result, moisture containing alkali metal ions permeates into the gap S between the external lead rod 16b and the sealing tube portion 13b formed on the end surface of the sealing tube portion 13b on the rear side, and the metal foil 15b and the quartz glass The state in which the airtight joint state between the two is cut and the airtightness of the arc tube portion 12 is leaked, or the joint portion between the external lead rod 16b and the metal foil 15b is cracked to cause a disconnection, resulting in a defect. Invite Compared with the conventionally known phenomenon in which alkali metal permeates from the outer surface of the sealing tube portion 13b and cuts the bonding between the quartz glass and the metal foil 15b, it is an electric conductor to the electrode. Alkali metal ions directly act on a certain external lead rod 16b or metal foil 15b, so that the life of the high-pressure discharge lamp 10 is almost zero, which is a very serious and serious problem.

  Although the high-pressure discharge lamp is a new lamp that has not reached the end of its service life, it is presumed that this is the reason why it could not be started from the beginning and caused defective products.

  To solve this problem, if the entire end of the sealing tube of the high-pressure discharge lamp is completely covered with a base or a holder as in the prior art, moisture adsorption and infiltration can be prevented. According to this, an increase in the size of the light source device is inevitable, and a request for downsizing the device cannot be achieved. It is also conceivable to cover the end of the sealing tube with the adhesive used to connect the high-pressure discharge lamp and the concave reflecting mirror. However, the alkaline inorganic adhesive is water-proof because it has a lot of voids in itself. Because of its poor nature, it cannot reliably block moisture.

  Therefore, the problem to be solved by the present invention is that the penetration of moisture containing alkali metal ions into the sealed tube part can be reliably blocked without increasing the size of the light source device, and the arc tube part leaks. It is possible to provide a light source device that can prevent the lamp from being turned off.

In order to solve the above-mentioned problems, the present invention includes a pair of electrodes, an arc tube portion in which 0.15 mg / mm ³ or more of mercury is enclosed, and a sealing tube portion continuously provided at both ends of the arc tube portion. A high pressure discharge lamp in which a metal foil is embedded in the sealing tube portion, a lead bar is connected to the rear end portion of the metal foil, and the lead rod protrudes from the rear end of the sealing tube portion. When,
A light source device comprising a light collecting unit that reflects light toward the front and a concave reflecting mirror having a cylindrical neck connected to the rear end of the light collecting unit,
One sealing tube portion of the high-pressure discharge lamp is inserted into the cylindrical neck portion, and an adhesive is filled between the sealing tube portion and the cylindrical neck portion in the rear portion of the cylindrical neck portion. The high pressure discharge lamp is fixed to the concave reflector,
A water-resistant insulating film is formed on the rear end surface of the sealing tube portion of the high-pressure discharge lamp.

The water-resistant insulating film is preferably formed on the surface of the adhesive.
Further, it is preferable that a black pigment is mixed in the water-resistant insulating film.

According to the present invention, since the water-resistant insulating film is formed on the end surface of the sealing tube portion of the high-pressure discharge lamp, the sealing tube portion does not infiltrate moisture containing alkali metal ions inside the sealing tube portion. Therefore, it is possible to prevent a situation where the high pressure discharge lamp does not light from the beginning of use of the light source device, and to provide a highly reliable light source device.
Further, according to the second invention of the present application, it is possible to prevent moisture from entering the alkaline inorganic adhesive, to suppress leakage of moisture containing alkali metal ions, and to reliably prevent leakage of the arc tube.
In addition, according to the third invention of the present application, the above-mentioned effect is achieved, and since the water-resistant insulating film contains the pigment, it is possible to prevent light from leaking from the lamp.

FIG. 1 is an axial cross-sectional view of a light source device according to a first embodiment of the present application.
Hereinafter, embodiments of the present invention will be described in detail.
In FIG. 1, this light source device accommodates a high-pressure discharge lamp 10 that is a light source and this high-pressure discharge lamp 10, reflects reflected light from the high-pressure discharge lamp 10, and projects the reflected light through an opening. The concave reflecting mirror 20 is provided. In the drawing, only a part of the high-pressure discharge lamp 10 is shown in a sectional view.

The light source device 1 is used with the tube axis of the high-pressure discharge lamp 10 in a horizontal state as shown in FIG.
Specifically, the concave reflecting mirror 20 includes a condensing part 21 that is concave and forms a condensing space, and a front outer edge part 23 that forms an opening at a front end (left end in FIG. 1) 21 a of the condensing part 21. And a base 20a composed of a cylindrical neck 24 extending rearward in the optical axis direction following a rear end (right end in FIG. 1) 21b of the light collecting portion 21 and visible light on the inner surface of the light collecting portion 21. The reflection layer 22 is formed and configured.

  As the substrate 20a of the concave reflecting mirror 20, glass such as borosilicate glass, quartz glass, or crystallized glass is preferably used. In addition, a metal can be used for the substrate 20a if the inner surface is subjected to a predetermined surface treatment.

A visible light reflecting layer 22 is formed on the inner surface of the condensing part 21 of the concave reflecting mirror 20.
The visible light reflecting layer 23 is composed of a dielectric multilayer film having a thickness of 0.5 to 10 μm, for example, in which a silica (SiO ₂ ) layer and a titania (TiO ₂ ) layer are alternately laminated, and mainly includes an infrared region. And has a function of transmitting light in the ultraviolet region and reflecting visible light.

  The high-pressure discharge lamp 10 includes a substantially elliptical arc tube portion 12 that forms a light emitting space, and a rod-shaped sealing tube portion 13a extending outward in the tube axis direction, that is, forward and backward in the optical axis direction, following both ends thereof. , 13b. The arc tube 11 is made of silica glass, and a pair of electrodes E1 and E2 are disposed inside the light emitting space so as to face each other. The arc tube portion 12 is filled with a rare gas as a lighting start gas, a halogen for suppressing blackening of the inner wall of the arc tube portion 11, and mercury as a luminescent material.

Electrode rods 14a and 14b are disposed in the arc tube portion 12 so as to protrude, and electrodes E1 and E2 are held at the tips of the rods 14a and 14b. The rear ends of the electrode rods 14a and 14b are embedded in the sealing tube portions 13a and 13b, and are further welded to the tip portions of the metal foils 15a and 15b sealed in the sealing tube portions. Specifically, such a metal foil is made of molybdenum. The rear ends of the metal foils 15a and 15b are connected to the external lead rods 16a and 16b, and are led out of the arc tube 11.
In the figure, W2 and W1 are power supply lines connected to the external lead bars 16a and 16b.

In the high-pressure discharge lamp 10, the amount of mercury enclosed in the arc tube 12 is preferably 0.15 mg / mm ³ or more, more preferably 0.25 mg / mm ³ or more. When the enclosed amount of mercury is 0.25 mg / mm ³ or more, high luminance is obtained in the high-pressure mercury lamp 10, so that higher light emission performance can be obtained in the light source device 10.

  On the end surface 13B of the sealing tube end portion 13b of the high-pressure discharge lamp 10, the water-resistant insulating film 40 is provided over substantially the entire area so as to cover the gap S formed between the external lead rod 16b and the sealing tube portion 13b. Is formed. Specifically, the water-resistant insulating film 40 is formed by directly applying a coating agent made of an aqueous suspension containing first aluminum phosphate, silicon dioxide, inorganic pigment, and the like onto the end surface 13B of the sealing tube portion 13b. It is an insulating film made of a phosphoric acid-based inorganic substance formed by drying, and the final water-resistant insulating film 40 has a thickness of 0.1 to 3 mm. Such a film thickness can be prepared as desired by changing the viscosity of the aqueous suspension, and the viscosity of the coating agent is preferably in the range of 5000 to 7000 mPa · S. This aqueous suspension has an acidic pH of 1.5 to 2.0, which can realize a high adhesive strength.

  The sealing tube portion 13b of the high-pressure discharge lamp 10 on the side where the water-resistant insulating film 40 is formed as described above is inserted into the cylindrical neck portion 24 of the base 20a, and the tube axis and concave surface of the high-pressure discharge lamp 10 are inserted. The mirror 20 is arranged substantially horizontally so that the optical axis of the reflecting mirror 20 coincides. Then, the light source device is completed by fixing with the adhesive 30 in a state where both are aligned.

As the adhesive 30 used here, an alkali-based inorganic ceramic adhesive is suitable from the viewpoint of heat resistance and adhesiveness. According to this, the high-pressure discharge lamp 10 can be stably held.
Here, the adhesive 30 is a position where the most advanced portion 30a is retracted from the welded portion K between the rear end portion of the electrode rod and the metal foil, more desirably a position retracted by 2 to 3 mm or more from the welded portion K. It is preferable that the high pressure discharge lamp 10 be filled without being applied to the rear end face of the sealing tube portion 13b.

According to such a light source device, since the water-resistant insulating film 40 is made of a phosphoric acid-based inorganic substance, it is alkali-free, and is excellent in waterproofness and moisture resistance, so that moisture is contained inside the sealing tube portion 13b. Infiltration can be surely prevented.
Therefore, even if the alkali metal ions contained in the adhesive 30 are eluted by exposure to an atmosphere with a lot of moisture, the end surface 13B of the sealing tube portion 13b is waterproofed by the water-resistant insulating film 40. It is reliably avoided that the moisture permeates into the gap S of the sealing tube portion 13b to hinder the hermetic sealing structure or the electrical connection state to be poor.
As a result, it is possible to avoid a problem at the time of initial lighting in which the lamp is not lit, and to provide a highly reliable light source device.

The coating agent constituting the water-resistant insulating film 40 includes CuCr ₂ O ₄ , Cu (Fe, Mn) ₂ O ₄ , Cu (Fe, Cr) ₂ O ₄ , (Co, Mn). When a black pigment such as Fe, Cr) ₂ O ₄ , Fe ₃ O ₄ , or carbon is mixed and used, the visible light emitted from the lamp 10 and transmitted through the sealing tube portion 13b is blocked. Thus, stray light can be prevented and infrared (IR) can be absorbed, so that a problem that infrared rays that generate heat are emitted to the outside of the light source device can be prevented. When black pigments are blended for the purpose of shielding visible light and infrared light in this way, the ratio of black pigments is preferably in the range of 0.5 to 10%.

  Moreover, in this invention, the water-resistant insulating film 40 should just be formed at least on the end surface 13B of the sealing pipe part 13b. Therefore, for example, as shown in FIG. 2, the water-resistant insulating film 40a may be continuously formed so as to cover the side surface portion of the sealing tube portion 13b.

  According to the light source device according to the first embodiment described above, since the waterproof treatment is performed by forming the water-resistant insulating film on the end face of the sealing tube portion, the moisture from the end portion of the sealing tube portion. No longer permeates. Therefore, even if water adheres to the adhesive and alkali metal ions are eluted in the water, it is prevented from infiltrating the inside of the sealing tube portion, and an external lead bar or metal embedded inside the sealing tube portion. The foil does not crack due to alkali metal ions, and the bonding between the metal and the quartz glass is not peeled off, so that it is possible to reliably prevent the problems that occur in the sealed tube portion.

Next, FIG. 3 is a view showing another embodiment of the present application, and is an axial sectional view of the light source device. The high-pressure discharge lamp is shown in a sectional view with a part cut away. Further, the same reference numerals as those shown in FIG. 1 are given to the same reference numerals, and detailed description thereof is omitted.
This embodiment is different from the first embodiment in that a second water-resistant insulating film is also formed on the surface of an adhesive mainly composed of an alkaline inorganic material.

  That is, in addition to forming the first water-resistant insulating film 41 on the sealing tube portion 13b of the high-pressure discharge lamp 10, the second water-resistant insulating film 42 is formed on the outer surface 30B of the adhesive 30. This prevents the alkali metal ions contained in the adhesive 30 from eluting into the water without water adhering to the adhesive 30. That is, it is possible to prevent the generation of water containing alkali metal ions, which is the root cause of lighting failure, and to reliably prevent the malfunction of the sealing tube portion 13b derived from the alkali metal ions.

Such water-resistant insulating films 41 and 42 are formed with the first water-resistant insulating film 41 on the sealing tube end face 13B of the high-pressure discharge lamp 20 in advance, and the concave reflecting mirror 20 and the high-pressure discharge lamp 10 are formed. After the adhesive 30 is fixed, the second water-resistant insulating film 42 may be formed on the outer surface 30B of the adhesive 30, or the high-pressure discharge lamp 10 and the concave reflecting mirror 20 may be bonded to the adhesive 30 first. The first water-resistant insulating film 41 and the second water-resistant insulating film 42 may be formed at the same time, that is, by applying the coating agent once.
The second water-resistant insulating film 42 is desirably formed so as to cover the entire adhesive outer surface 30B up to the end surface of the cylindrical neck portion 24 of the concave reflecting mirror 20, and according to this, The agent 30 can be reliably waterproofed.

  As described above, according to the present embodiment, since the outer surface of the adhesive is waterproofed by being covered with the water-resistant insulating film, moisture does not adhere to the adhesive, and thus alkali metal ions are dissolved in water. It is possible to prevent the occurrence of defects in the sealed tube portion derived from alkali metal ions.

Next, FIG. 4 is a view showing still another embodiment of the present invention, and is an axial sectional view of the light source device showing an enlarged main part. In addition, about the same code | symbol as the structure shown previously in FIGS. 1-3, it shows with the same code | symbol and abbreviate | omits detailed description.
In this embodiment, in the adhesive 30 that joins the high-pressure discharge lamp 10 and the concave reflecting mirror 20, the insulation made of a phosphoric inorganic material is also formed on the surface exposed to the visible light reflecting surface 22 side of the concave reflecting mirror 20. A film is formed, and a third water-resistant insulating film 43 is formed. Accordingly, the entire surface of the adhesive 30 is waterproofed, and the alkali metal ions are completely prevented from dissolving in water, and the alkali metal ions are reliably prevented from entering the sealing portion of the high-pressure discharge lamp. The

  In some light source devices, a plate-like glass member is arranged along the front end surface of the concave reflecting mirror 20 so that the inside of the light collecting surface is substantially sealed. In such a light source device, However, the airtightness is not maintained because it has an opening for leading out the feeder line. Therefore, it is possible to circulate moisture as well as water vapor in the external atmosphere, and the possibility of water immersion on the surface of the adhesive 30 exposed on the visible light reflecting surface 22 of the concave reflecting mirror 20 cannot be denied. Therefore, as in this embodiment, the elution of alkali metal ions is completely prevented by forming the third water-resistant insulating film 43 not only on the rear surface of the adhesive 30 but also on the front surface. It is possible to reliably prevent problems with the sealing tube portion derived from such alkali metal ions.

According to the present invention described above, in the light source device in which the gap between the sealing tube portion and the concave reflecting mirror is directly fixed with an adhesive, the water-resistant insulating film is formed on the end surface of the sealing tube portion of the high-pressure discharge lamp. Even if the light source device is brought into an atmosphere where the humidity is high and exposed to moisture, it is possible to suppress the situation in which the water from which the alkali metal ions have dissolved out into the end of the sealing tube portion. Problems caused by directly acting on the rod and the metal foil can be reliably prevented.
And since the adhesive itself is waterproofed by forming a water-resistant insulating film also on the outer surface of the adhesive that fixes between the sealing tube portion and the concave reflecting mirror, the alkali metal ions are dissolved. Can be prevented, and higher reliability can be obtained.
As a result, without increasing the size of the light source device, it is possible to avoid a situation in which the high pressure discharge lamp does not light from the beginning of use of the light source device, and it is possible to provide a highly reliable light source device.

  Although the embodiment of the present invention has been described, it is needless to say that the present invention is not limited to the above configuration and can be modified as appropriate. For example, the configuration of the concave reflecting mirror can be applied in addition to the glass-based substrate as in the above-described embodiment. Specifically, a glass coating is applied to the reflecting surface while using a metal as a base material. Needless to say, the present invention can also be applied to a light source device in which a dielectric multilayer film is formed to produce a reflecting mirror and a light source lamp is provided therein.

[Example 1]
A light source device according to the present invention was produced based on the configuration of FIG.
A visible light reflecting layer made of a silica-titania dielectric multilayer film was formed on the inner surface of the condensing part of the substrate of the concave reflecting mirror made of borosilicate glass.
The maximum outer diameter of the concave reflecting mirror (20) was 46 mm, the outer diameter of the cylindrical neck (24) was 16 mm, and the condensing part (21) had a curved surface made of a spheroid. The cylindrical neck (24) had an inner diameter of 10 mm and an axial length of 10 mm.

The high-pressure discharge lamp (10) has an AC lighting type and an arc tube (11) made of quartz glass, and the diameters of the sealing tube portions (13a, 13b) are 6 mm and the length is 10 mm. The arc tube portion (12) had a maximum outer diameter of φ10 mm and a length of 12 mm. In this high pressure discharge lamp (10), electrodes (E1, E2) made of tungsten are arranged oppositely inside the arc tube portion (12), mercury as a luminescent substance is 0.2 mg / mm ³ , and bromine is enclosed. In addition, a metal foil welded to the rear end of the electrode is interposed in the sealing tube portion (13a, 13b) and hermetically sealed by a shrink seal and an external lead rod is derived.

A coating agent comprising a suspension containing 1% CuCr ₂ O ₄ as a black pigment in the first aluminum phosphate and silicon dioxide over the entire end face of the sealing tube portion of the high-pressure discharge lamp produced as described above. Brush coating was applied to a heat and water resistant inorganic coating agent manufactured by Telnic Industry Co., Ltd. The coating agent had a viscosity of 7000 mPa · S and a pH of 2. This was dried at 100 ° C. for 3 to 5 minutes and then baked at 230 ° C. for 10 minutes to form a water-resistant insulating film having a thickness of about 0.5 mm.

  Inorganic alkaline system by placing one of the sealed tube parts in the cylindrical neck and placing the high pressure discharge lamp so that the first focal point of the curved surface of the condensing part of the concave reflecting mirror coincides with the bright spot of the high pressure discharge lamp Filled with adhesive. The adhesive filling position was such that the front end portion was 3 mm behind the connecting portion between the metal foil and the external lead rod in the high-pressure discharge lamp, and 2 mm ahead of the end face of the sealing tube portion.

[Comparative Example 1]
According to the configuration of FIG. 3, a light source device according to Comparative Example 1 having the same configuration as that of Example 1 except that a water-resistant insulating film was not formed on the end surface of the sealing tube portion of the high-pressure discharge lamp was manufactured.

[Experimental example]
The light source device according to Example 1 and the light source device according to Comparative Example 1 were placed in a sealed space, the temperature was set to 30 ° C., and the humidity was maintained in the range of 70 to 100%, and left for 240 hours. Then, after moving to a room with a temperature of 25 ° C. and a humidity of 40%, the high-pressure discharge lamp was turned on with a rated power consumption of 200 W (voltage 85 V, current 2.4 A).

As a result, it was confirmed that the high-pressure discharge lamp of the light source device according to Example 1 was lit without any problem and was lit stably even after a predetermined lamp service life had elapsed.
On the other hand, the high-pressure discharge lamp according to Comparative Example 1 was disconnected at the connecting portion between the metal foil embedded in the sealing tube portion and the external lead rod, and was unable to light up and could not be lit. The reason for this is that alkali metal ions are eluted in the moisture adhering to the surface of the adhesive, and this penetrates between the external lead rod and the quartz glass from the end face of the sealing tube, so that there is a crack in the joint between the external lead rod and the metal foil. It is thought that it entered.

It is an axial sectional view of the light source device according to the first embodiment of the present invention. It is an axial sectional view showing an enlarged main part of a high-pressure discharge lamp according to another embodiment of the present invention. It is an axial sectional view of a light source device according to another embodiment of the present invention. It is an axial sectional view of a light source device according to another embodiment of the present invention. It is sectional drawing for description of the light source device which concerns on a prior art.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 High pressure discharge lamp 11 Light emission tube 12 Light emission tube part 13a, 13b Sealing tube part 14a, 14b Electrode rod 15a, 15b Metal foil 16a, 16b External lead rod E1, E2 Electrode Wc Auxiliary electrode Wt Feed line 20 Concave reflector 20a Base 21 condensing part 21a condensing part front end 21b condensing part rear end 22 visible light reflecting layer 23 front outer edge part 24 cylindrical neck part 30 adhesive 40, 40a water resistant insulating film 41 first water resistant insulating film 42 second Water-resistant insulating film 43 Third water-resistant insulating film

Claims (3)

A pair of electrodes, an arc tube portion in which 0.15 mg / mm ³ or more of mercury is enclosed, and a sealing tube portion continuously provided at both ends of the arc tube portion; A high pressure discharge lamp in which a metal foil is embedded, a lead bar is connected to the rear end of the metal foil, and the lead bar protrudes from the rear end of the sealed tube part;
A light source device comprising a light collecting unit that reflects light toward the front and a concave reflecting mirror having a cylindrical neck connected to the rear end of the light collecting unit,
One sealing tube portion of the high-pressure discharge lamp is inserted into the cylindrical neck portion, and an adhesive is filled between the sealing tube portion and the cylindrical neck portion in the rear portion of the cylindrical neck portion. The high pressure discharge lamp is fixed to the concave reflector,
A light source device, wherein a water-resistant insulating film is formed on a rear end surface of a sealing tube portion of the high-pressure discharge lamp.   The light source device according to claim 1, wherein the water-resistant insulating film is also formed on a surface of the adhesive. 2. The light source device according to claim 1, wherein a black pigment is mixed in the water-resistant insulating film.

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