JP2006079957A - Discharge lamp device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a discharge lamp system, of which a light emission part of a discharge lamp is hardly shifting from a light axis of a reflection film, capable of efficiently utilizing light emitted from a discharge lamp without blocking the light at a bulb thereof, and capable of stably taking out the light with high efficiency. <P>SOLUTION: The discharge lamp device comprises a glass block having a transparent reflection part formed into a hemispheric shape and a light-take-out part formed so as to face the reflection part; a pair of electrodes formed almost at the center of the glass block, arranged so as to face a discharging space; and a reflection film formed on an outer surface of the reflection part of the glass block. Light generated between the electrodes is transmitted through the glass block, reflected at the reflection part, transmitted through the glass block again, and emitted outward from the light-take-out part. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a discharge lamp device in which a discharge lamp and a light reflecting film are combined.

  In recent years, a discharge lamp device including a discharge lamp and a reflecting mirror is often used as a light source that emits high-luminance light. In particular, as a light source for a data projector, there is known a light source provided with an ultrahigh pressure mercury discharge lamp that is small in size and provides high brightness in a reflecting mirror made of quartz glass.

  In the data projector industry, simplicity in carrying around is required, and a smaller projector device is strongly demanded. Due to such a demand, there is an increasing demand for miniaturization of the discharge lamp device built in the projector apparatus.

In the discharge lamp device used in the above-mentioned applications, various discharge lamp devices in which the shape of the built-in discharge lamp or reflecting mirror has been devised for miniaturization and high brightness have been proposed. Japanese Patent Laid-Open No. 2002-150999 discloses that an infrared reflecting film is formed on the outer surface of the arc tube outside the effective light use angle of the high-pressure mercury discharge lamp, thereby reducing the arc tube temperature of the high-pressure mercury discharge lamp and reducing the size of the reflection. A discharge lamp device in which a high-pressure mercury discharge lamp is arranged in a mirror is described.
Japanese Patent Laid-Open No. 2003-241309 discloses a technique for reducing the size of the main mirror by about half by providing an auxiliary mirror that returns half of the light emitted from the high-pressure mercury discharge lamp back to the high-pressure mercury discharge lamp. It is disclosed.

FIG. 6 is a sectional view of a discharge lamp device according to the prior art. The discharge lamp device 51 includes a reflecting mirror 52 made of quartz glass, a discharge lamp 53 included in the reflecting mirror 51, and a front glass 54 covering the opening side of the reflecting mirror 52. On the inner surface side of the reflecting mirror 52, a light reflecting film 55 made of, for example, a dielectric multilayer film is formed. The discharge lamp 53 includes a substantially spherical bulb 56, an electrode 57 disposed opposite to the bulb 56, and a sealing portion 58 protruding from the bulb 56. A base 59 may be attached to one end of the sealing portion 56.
The sealing portion 56 is embedded with a base end portion of an electrode rod following the electrode 57 and a metal foil 60 made of molybdenum (Mo) or the like continuously provided therewith, and an external lead rod is provided at the outer end portion of the metal foil 60. 61 is connected and derived.

  In the discharge lamp device 51, a light reflecting film 62 is provided on the bulb 56 near the sealing portion 58 of the discharge lamp 53. This light reflecting film is used to reflect the light emitted from the front part of the bulb out of the light emitted from the discharge lamp 53 again into the discharge space. According to this, the light reflecting film was not used. The light can be reused, and the light blocked by the arc tube 56 can be used with high efficiency.

  However, in the conventional discharge lamp apparatus as described above, since the discharge lamp is disposed and used inside the reflecting mirror, there is a limit to downsizing the discharge lamp apparatus, and the recent demand has been achieved. It wasn't good.

In addition, there are the following problems.
First, the light reflected on the side of the discharge lamp that is fixed to the reflecting mirror and in the vicinity of the sealing portion of the reflecting mirror is often blocked by the bulb of the discharge lamp, and as a result, the emitted light from the lamp is reduced. It cannot be used effectively.

In addition, since the discharge lamp and the reflecting mirror are made of different members, the discharge lamp must be accurately arranged on the optical axis of the reflecting mirror, but this requires very high accuracy. Production is extremely difficult.
Even if it can be manufactured with high accuracy, an adhesive is usually used when fixing the discharge lamp to the reflecting mirror, and the thermal expansion of the adhesive when the lamp is lit or the lamp is lit for a long time. Due to the deterioration of the adhesive due to repeated flashing, the center of the arc of the lamp and the optical axis of the reflecting mirror may shift, and light cannot be emitted with high efficiency until the end of the lamp life.

Therefore, for example, it can be considered to use a short arc lamp device in which a reflecting mirror and a discharge lamp described in JP-A-9-161727 are integrated.
According to such a lamp, since the arc tube is not provided in the inner region of the light reflecting film of the reflecting mirror, the light reflected by the light reflecting film is not blocked by the arc tube, and the utilization rate of the spectrum is reduced. In addition, since the lamp body and the reflecting mirror are integrated, there is a possibility that a reduction in size can be achieved.

However, in this lamp, when the pair of electrodes are held so that the axes of the electrodes are aligned with the optical axis of the reflecting mirror, the electrode located in front of the optical axis is supported in a hollow state so that the electrode serves as a lead. However, when the support member is thermally expanded, the position of the electrode is easily displaced, so that the center of the arc is displaced from the optical axis of the light reflecting film, and the light is sufficiently absorbed. It can no longer be captured.
In addition, the electrode support member must be relatively large and sturdy in order to support the electrode, which causes a problem that the emitted light is blocked.
Furthermore, since the volume of the discharge space depends on the volume inside the reflecting mirror, it is difficult to increase the pressure inside the discharge space and it is difficult to obtain a desired luminance.
JP 2002-150999 A JP 2003-241309 A JP-A-9-161727

  Therefore, the problem to be solved by the present invention is that the light emitted from the discharge lamp is not blocked by the bulb of the discharge lamp, and the light emitted from the discharge lamp can be used efficiently. It is an object of the present invention to provide a discharge lamp device in which the light emitting part of the discharge lamp is not easily displaced from the optical axis of the reflective film and can stably extract light with high efficiency.

In order to solve the above-described object, a discharge lamp device according to the present invention includes a light-transmitting reflecting portion having an outer shape formed in a substantially hemispherical shape and a light extraction portion formed so as to face the reflecting portion. A glass block having an airtight air gap at the substantially center of the glass block to form a discharge space, a pair of electrodes opposed to face the discharge space, and the glass block, A discharge lamp device comprising: a lead portion supported and extending outward; and a reflective film formed on an outer surface of the reflective portion of the glass block, wherein light generated between the electrodes Then, the light passes through the glass block, is reflected by the reflection part, passes through the glass block again, and is emitted from the light extraction part.
Further, at least a part of the reflecting portion is formed by a spheroid or a paraboloid.
Furthermore, the lead portion is arranged along the optical axis of the light reflecting film.
The lead portion is made of a metal wire and / or a metal foil.

  According to the discharge lamp device according to the present invention, the light emitted from the discharge lamp is not blocked by the bulb of the discharge lamp, and the light emitted from the discharge lamp can be used with high efficiency. Further, it is possible to prevent the light emitting portion of the discharge lamp from deviating from the optical axis of the light reflecting film, and it is possible to stably extract light with high efficiency by turning on the lamp.

Hereinafter, embodiments of the discharge lamp device of the present invention will be described in detail. FIG. 1 is a schematic sectional view of an example of a discharge lamp device according to the present invention, (a) a sectional view for explanation, and (b) a front view.
In this discharge lamp device 1, the bulb 10 has a light-transmitting, substantially hemispherical glass block 11 made of solid quartz glass, and one end surface 11a and the other end surface 11b of the block 11. Is configured to include cylindrical sealing portions 12a and 12b that are continuously provided so as to extend outward.

  A substantially elliptical spherical space is airtightly provided at a substantially central portion of the glass block 11, and a sealed gas made of a rare gas such as xenon, argon, or krypton, or a mixture thereof, and a light emitting material such as mercury or metal halide. Is enclosed to form a discharge space S. In the discharge space S, a pair of electrodes composed of an anode 20a and a cathode 20b are arranged to face each other.

A light reflecting film R is formed on one end face 11 a of the glass block 11, and a reflecting portion 110 is formed. The light reflection film R reflects light emitted inside the glass block 11 toward the other end surface 11b where the light extraction portion M is formed. The light reflecting film R is composed of a dielectric multilayer film or a metal vapor-deposited film. In the dielectric multilayer film, one layer is composed of about a dozen TiO ₂ —SiO ₂ layers having a thickness of about 0.1 to 0.2 μm. In the case of a laminate of 30 or more layers, or a metal vapor deposition film, an aluminum vapor deposition film having a film thickness of about 1 to 10 μm is used.

The light extraction part M is formed to have a plane substantially orthogonal to the optical axis L in the discharge lamp device 1.
Although the reflection part 110 has been described as having a substantially hemispherical shape in the above description, specifically, the reflection part 110 is a surface that can reflect the light emitted between the electrodes 20a and 20b toward the light extraction part M, and specifically, the light of the lamp device. It consists of a rotating paraboloid or a rotating ellipsoid about the axis L.
The pair of electrodes 20a and 20b are arranged so that the center position serving as the bright spot of the arc is located on the optical axis L. In particular, when the reflecting portion 110 is formed of a spheroid, the focal point of the ellipsoid is obtained. Adjusted to match.

The anode 20a and the cathode 20b are both made of tungsten, and are fixed and held at the tip portions of the lead portions 21a and 21b embedded and supported in the sealing portions 12a and 12b of the bulb 10.
The lead portions 21a and 21b are connected to electrode rods 211a and 211b for holding the electrodes 20a and 20b, and rear end portions of the electrode rods 211a and 211b, and a metal foil 212a made of molybdenum (Mo) or the like that forms a seal portion. 212b and external lead rods 213a and 213b that are connected to the outer end portions of the metal foils 212a and 212b and are exposed to the outside for power feeding, and are supported by the glass block 11 via the sealing portions 12a and 12b. , That stretches outward. In addition, in the part embedded in the glass block 11 in the electrode rods 211a and 211b, it is good also as a structure which arrange | positions coils 214a and 214b around the outer periphery as shown in the figure, or winds a metal wire. In this way, the difference in thermal expansion between the quartz glass of the glass block 11 and the electrode rods 211a and 211b is buffered, so that breakage of the glass can be avoided and leakage can be prevented.

  According to the discharge lamp device 1 having the above-described configuration, the light emitted between the pair of electrodes (20a, 20b) is transmitted through the glass block 11 and has a reflecting portion as indicated by an arrow in FIG. The one end surface 11a to be formed is incident on and reflected by the light reflecting film R, and the reflected light passes through the glass block 11 again and finally exits from the light extraction portion M on the other end surface 11b. As described above, the light converted into the condensed light in the reflecting portion is transmitted through only the inside of the glass block 11 surrounding the discharge space S and is emitted, so that it is possible to use the light with higher efficiency than in the past. And the emitted light from the discharge lamp device can be increased.

In the lamp device according to the prior art, since the reflector and the discharge lamp are formed of separate members to form a space, the bulb becomes a light shielding object for the light reflected by the reflector, thereby cutting the reflected light. It was not able to use enough.
Thus, according to the present invention, the light reflecting film R is directly disposed on the outer surface of the bulb 11, and the reflected light is transmitted through only the inside of the glass block 11, and thus is blocked by the bulb in the conventional product. The light that could not be used can be used, and an increase in the emitted light from the discharge lamp device 1 can be achieved.

  Further, in the discharge lamp device 1 according to the above configuration, the electrodes 20a and 20b are held by the glass block 10 via the sealing portions 12a and 12b, and the light reflecting film R and the pair of electrodes (20a and 20b). The adhesive is fixed without being used. For this reason, there is no deviation between the electrode (the center of the arc) and the reflecting part due to the thermal expansion of the adhesive when the lamp is lit or the deterioration of the adhesive, etc. A discharge lamp device that can emit light with high efficiency and is suitable as a light source for a data projector can be provided.

  Further, since the electrodes 20a and 20b are held with the lead portions 21a and 21b embedded in the sealing portions 12a and 12b, the positions of the electrodes (20a and 20b) fluctuate even if the lead portions 21a and 21b are thermally expanded. There is no such thing. Therefore, as in the short arc lamp device in which the reflecting mirror and the discharge lamp described in the above cited reference 3 (Japanese Patent Laid-Open No. 9-161727) are integrated, the center of the arc is greatly deviated from the optical axis. Can also be avoided.

Hereinafter, the manufacturing method of the glass block which concerns on this invention is demonstrated based on an Example.
First, a first manufacturing method of the discharge lamp device will be described with reference to FIG. In this manufacturing method, a cylindrical tube made of quartz glass is heated and formed by an oxygen-hydrogen mixed burner and processed so as to increase the thickness around the discharge space.
The material of the bulb (10) is, for example, a cylindrical quartz glass tube having an outer diameter of 6 mm, an inner diameter of 2 mm, and a length of 300 mm with both ends open. The quartz glass tube is formed by a carbon roller for forming while being heated by an oxygen-hydrogen mixed burner, and the substantially elliptical hollow portion 30a for forming the discharge space (S) is formed at the substantially center of the glass tube 30. To form. In parallel with this, the thick part 31 for forming the glass block (11) is produced by increasing the peripheral thickness of the hollow part 30a. The thick portion 31 is substantially hemispherical, and is shaped so that one end surface is substantially hemispherical and the other end surface is a flat surface substantially perpendicular to the tube axis of the glass tube.

Fig.2 (a) is sectional drawing of the glass tube which shows the state after shaping | molding. As shown in the figure, hollow branch tube portions 32a and 32b are connected to both ends of the thick portion 31, and the inside of the branch tube portions 32a and 32b is a hollow portion 30a for forming a discharge space (S). It communicates with the inside.
The size and shape of each part at this stage are the outer diameter on the light emitting side is φ40 mm, the light reflecting film side is a paraboloid shaped around the axis of the tube, the discharge space size is 2.5 mm at the maximum inner diameter, The internal volume is about 120 mm ³ . The focal point (distance) is 7 mm. The branch pipe portion 3 is derived from a quartz glass tube shape as a material, and has an outer diameter of 6 mm and an inner diameter of 2 mm.

Electrodes 20a and 20b shown in FIG. 2B are made of tungsten, and have an anode (20b) diameter of φ1.8 mm and a cathode (20a) diameter of φ0.8 mm.
The electrodes 20a and 20b include electrode bars 211a and 211b connected to the electrodes 20a and 20b, metal foils 212a and 212b connected by welding at base ends of the electrode bars 211a and 211b, and the metal foils. The other end portions of 212a and 212b are connected to lead portions 21a and 21b constituted by external lead rods 213a and 213b connected by welding. The electrode rods (211a, 211b) are made of tungsten and have a diameter of 0.4 to 0.7 mm and a length of 3 to 5 mm. A tungsten coil is arranged around the outer periphery or a molybdenum wire is wound.
The electrodes 20a, 20b and the lead portions 21a, 21b are preheated in a hydrogen atmosphere, and are inserted through the openings (see FIG. 2A) at both ends of the branch tube portions 12a, 12b of the glass tube 30, It arrange | positions adjusting the distance between electrodes and an electrode position.
Thereafter, in the argon (Ar) atmosphere, an enclosure and an enclosure gas are introduced to seal both ends of the branch pipe portions 32a and 32b. As the inclusion H, for example, 30 mg of mercury and 5 μg of bromine (Br) are introduced.

Subsequently, the branch pipe portions 32a and 32b are sealed. FIG. 2C is a diagram showing a state where the sealing is completed.
In such a sealing step, first, one branch pipe part (for example, the branch pipe part 32a) is heated and melted by an oxygen-hydrogen mixed burner, and the metal foil 212a and quartz glass are welded. In this step, the quartz glass tube is cooled by water cooling or liquid nitrogen depending on the type of inclusions. Thereafter, the other branch pipe part 32b is similarly welded with the metal foil 212b and the quartz glass of the branch pipe part 32b to form an airtight seal part.

After the entire annealing process, the quartz glass around the outer lead bars 213a and 213b is removed.
Thereafter, the lamp device main body is completed after aging. A predetermined light reflecting film is provided on the outer surface of the spherical portion of the lamp device body to form a light reflecting film (R), thereby completing the discharge lamp device.
FIG.2 (d) is a figure of the last form of a discharge lamp apparatus.

In the discharge lamp device manufactured as described above, the light emitted between the electrodes passes through the quartz glass block and directly enters the light reflecting film, and the light reflected by the light reflecting film is again reflected in the glass block. Since the light is emitted from the light extraction portion through the light, the light emitted from the discharge lamp is not blocked by the bulb of the discharge lamp, and the light emitted from the discharge lamp can be used effectively. become.
In addition, since the lead part is held by the sealing part which is a part of the glass block, the electrode position is prevented from fluctuating due to thermal expansion of the lead part itself, and the center of the arc is greatly deviated from the optical axis. It is prevented. In addition, since the electrode can be supported without using a large member as the lead member, shielding the radiated light by the lead portion is reduced.

A second manufacturing method of the discharge lamp device different from the above will be described with reference to FIG. In addition, in the same structure as the structure of the discharge lamp apparatus demonstrated in the said FIG. 1, FIG. 2, it shows with the same code | symbol, and abbreviate | omits the description.
FIG. 3A is a cross-sectional view of a glass block surrounding the discharge space (S) of the bulb (10). The glass block 41 is formed by cutting solid quartz glass.
The outer shape of the glass block 41 is substantially hemispherical, one end surface 41a is formed in a substantially hemispherical shape, and the other end surface 41b is formed in a flat shape. A through hole 40 is provided in the central portion of the glass block 41, and a substantially elliptic spherical cavity 40a for forming a discharge space (S) is formed in the approximate center of the through hole 40.
In the glass block 41, the shape of the one end surface 41a is specifically a paraboloidal shape, and the other end surface 41b has a circular shape with an outer diameter of φ40 mm. The cavity 40a has a maximum inner diameter of 2.5 mm and an internal volume of about 120 mm ³ . The focal point (distance) is 7 mm.
In the through hole 40, constricted portions 401a and 401b are formed at both ends of the cavity portion 40a, and a step portion is formed on the outer side by increasing the inner diameter, and an insertion portion 402a for an electrode sealing body. , 402b are formed.

Subsequently, with reference to FIG. 3B, a sealing body made of an electrode, a lead portion, and quartz glass will be described.
The lead portions 21a and 21b connected to the electrodes 20a and 20b are constituted by electrode rods 211a and 211b, metal foils 212a and 212b, and external lead rods 213a and 213b. A coil is attached or a metal wire is wound.

The mount comprising the electrodes 20a, 20b and the lead portions 21a, 21b is inserted into a quartz glass tube (not shown) cut longer than the entire length of the mount, and one end of the quartz glass tube is sealed. The inside of the glass tube is evacuated and the surroundings of the glass tube are heated and gas is discharged by heat treatment. After that, the other end of the glass tube is also sealed, and the inside is kept in a reduced pressure state. Make a glass tube. Thereafter, the vicinity of the electrode rods 211a and 211b and the metal foils 212a and 212b is heated and sealed to produce a sealed body in which the lead portions 21a and 21b are embedded in the sealed portions 12a and 12b. Such sealing bodies 42a and 42b are removed by cutting unnecessary quartz glass tubes before proceeding to the next step (see FIG. 3B).
The electrodes 20a and 20b are made of tungsten, and the diameters thereof are an anode diameter φ1.8 mm and a cathode diameter φ0.8 mm, respectively. The length from the tip of the electrode to the rear end of the external lead rod (213a, 213b) is, for example, 8 to 15 mm.

Subsequently, the glass block 41 and the sealing body shown in FIG. 3B are introduced into a glove box in an argon (Ar) atmosphere. Predetermined inclusions such as mercury and halogen are introduced from the insertion portions 41a and 41b of the sealing portions 12a and 12b formed in the glass block 41, and the electrodes 20a and 20b of the sealing bodies 42a and 42b are hollow portions. It is inserted so as to be arranged at a predetermined position of 400. A sealing glass (not shown) for quartz glass is disposed in the gap between the glass block 41 and the sealing bodies 42a and 42b, and the vicinity of the contact portion is heated by induction heating with a carbon ring or the like. The sealing bodies 42a and 42b are welded. In addition, the enclosure H of this Example 2 is mercury and Br similarly to the case of the said Example 1, and the amount of enclosure is also the same. The sealing glass contains SiO ₂ at a ratio of 77 mol% or more, and has a linear expansion coefficient approximate to that of the glass block 41. Preferably, the linear expansion coefficient of the glass block 41 is ± 6. In the range of × 10 ⁻⁷ [K ⁻¹ ], it is preferable to soften at a temperature lower than the melting point of quartz glass and to have a characteristic that the contact angle with quartz glass at 20 ° C. after softening is 80 degrees or less. (Refer to Unexamined-Japanese-Patent No. 2001-240428).

Thus, as shown in FIG. 3C, a discharge lamp portion comprising a bulb 10 comprising a glass block 11 and sealing portions 12a, 12b, a pair of electrodes 20a, 20b, and a pair of lead portions 21a, 21b. Is completed. In the case of the manufacturing method according to the present embodiment, the enclosure H enclosed in the discharge space S is limited to a solid or liquid at room temperature. In the case of the present embodiment, the sealed gas is limited to argon (Ar).
A predetermined light reflecting film (R) is formed on the one end face 41a of the discharge lamp thus obtained, and the discharge lamp device 1 shown in FIG. 3 (d) is completed.

While the present invention has been described based on the embodiments, it is needless to say that the present invention is not limited to the above-described configuration and can be changed as appropriate.
For example, the lead portion has been described with an example composed of an electrode rod, a metal foil, and an external lead rod. For example, the functionally graded material disclosed in Japanese Patent No. 3118758, Japanese Patent No. 3460537, etc. Such a technique can be applied to produce and configure a sealed body. FIG. 4 is an example in which a sealing body is configured using such a functionally gradient material. In the figure, the same components as those described above are denoted by the same reference numerals and description thereof is omitted.
Thus, the structure of the lead portions 21a and 21b can be configured without using metal foil. When the sealing portions 12a and 12b are configured using a functionally gradient material, the one ends 121a and 121b on the electrode side are made of an insulating inorganic material layer, and each of the conductive inorganic material component and the insulating inorganic material component A plurality of mixture layers made of a mixture are stacked, and each of the mixture layers has a hole 122a extending in the stacking direction in which the ratio of the conductive inorganic material component is increased stepwise in order from the one adjacent to the insulating inorganic material layer. Sealing members F1 and F2 are made of a functionally graded material made of a laminate in which 122b is formed, and electrode rods 211a and 211b as lead portions 21a and 21b are connected to holes 122a and the sealing members F1 and F2, respectively. 122b, and sealing members F1 and F2 and electrode rods 211a and 211b are hermetically fixed to form a sealing body, which is the same as that described in the second embodiment. Tsu be produced by a combination of a click.

In the present invention, the light extraction portion can be configured to be tilted as desired in consideration of the refractive index of quartz glass in addition to a plane perpendicular to the optical axis. Moreover, it is not limited to the form comprised with a flat surface, It is also possible to change into shapes other than a plane so that appropriate optical operation may be performed to reflected light.
For example, in the apparatus in which the present discharge lamp apparatus is incorporated, as shown in FIG. 5, when a plurality of optical elements are appropriately arranged in front of the light extraction unit, the light extraction unit is configured to have the role of an optical system. Is possible. In FIG. 5, the same components as those described above are denoted by the same reference numerals, and the description thereof is omitted.
For example, FIG. 2 shows an example in which a Fresnel lens-like lens portion M1... Is provided in the light extraction portion M so as to correspond to the optical element O arranged in front of the discharge lamp device.
In the case where the light extraction unit M is provided with a light polarization function as in this embodiment, one of the optical elements disposed in a device such as a data projector in which the discharge lamp device is incorporated is reduced. Further downsizing can be realized.

  In the case where the light extraction portion M is provided with an optical function as in this embodiment, the light extraction is performed when the direction of the electrode (and the lead portion) is arranged in a direction substantially orthogonal to the optical axis of the discharge lamp device 1. It is convenient that the lens portions M1... Can be formed over the entire portion M. Of course, the lens shape is appropriate other than the Fresnel lens shape, and may be a lens shape that focuses light at one point like an integrator lens (illustration is omitted). In either case, the lens shape can be easily realized by molding in advance with a mold.

1 is a cross-sectional view illustrating a configuration of a discharge lamp device according to the present invention. It is a figure for demonstrating the 1st manufacturing method of the discharge lamp apparatus which concerns on this invention. It is a figure for demonstrating the 2nd manufacturing method of the discharge lamp apparatus which concerns on this invention. It is the example which comprised the sealing body for the discharge lamp apparatus which concerns on this invention using the functionally gradient material. The discharge lamp device according to the present invention is an example in which a light extraction portion is provided with a Fresnel lens-shaped uneven portion. It is sectional drawing explaining the discharge lamp apparatus which concerns on a prior art.

Explanation of symbols

DESCRIPTION OF SYMBOLS 100 Discharge lamp apparatus 10 Bulb 11 Glass block 11a One end surface 11b The other end surface 12a, 12b Sealing part 20a, 20b Electrode (anode, cathode)
21a, 21b Lead portions 211a, 211b Electrode rods 212a, 212b Metal foils 213a, 213b External lead rods 214a, 214b Coil 30 Glass tube 30a Cavity 31 Thick portions 32a, 32b Branch tube 40 Through hole 40a Cavities 401a, 401b Narrow part 402a, 402b Insertion part 41 Glass block 41a, 41b Insertion part 42a, 42b Sealing body L Optical axis S Discharge space M Light extraction part M1 Lens part F1, F2 Sealing member O Optical element

Claims (4)

A glass block having a light transmission and having a reflection part whose outer shape is formed in a substantially hemispherical shape and a light extraction part formed to face the reflection part;
A gap is formed in an airtight manner at the approximate center of the glass block to form a discharge space, and a pair of electrodes arranged to face the discharge space;
A lead portion that is connected to the electrode and is supported by a glass block and extends outward;
A reflective film formed on the outer surface of the reflective portion of the glass block;
A discharge lamp device comprising:
The discharge lamp device characterized in that light generated between the electrodes passes through the glass block and is reflected by the reflecting portion, passes through the glass block again, and is emitted from the light extracting portion.   The discharge lamp device according to claim 1, wherein at least a part of the reflection portion is formed of a spheroid or a paraboloid.   The discharge lamp device according to claim 2, wherein the lead portion is disposed along an optical axis of the light reflecting film. 4. The discharge lamp device according to claim 1, wherein the lead portion is made of a metal wire and / or a metal foil.

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