JP2008041365A - Manufacturing method of concave reflection mirror, mold for concave reflection mirror manufacture, and concave reflection mirror and light source device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a manufacturing method of a concave reflection mirror having a second reflecting surface of spherical-surface shape continued from a first reflecting surface in which a reflection film can be certainly formed as expected, and a high utilization efficiency of light can be realized, as adjustment of focus position can be made extremely simply even if they are different reflecting surfaces, with good productivity and at a low cost. <P>SOLUTION: This is a manufacturing method of a concave reflection mirror made of glass in which the first and the second reflecting surfaces are arranged in this order from the front side of an optical axis, and comprises a process in which a base body of the concave reflection mirror is formed integrally by hot press so that a splitting margin may be formed between a first reflecting surface part and a second reflecting surface part, a process in which the base body is cut at the splitting margin and the base body is split in front and rear directions of the optical axis, a process in which the light reflection film is formed on each of the first reflecting surface part and the second reflecting surface part to construct the first reflecting surface and the second reflecting surface, and a process in which the base body is recombined and integrated so that the first reflecting surface and the second reflecting surface may be continued. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a light source device used for a backlight of a projection type projector device such as a liquid crystal display device, DLP (registered trademark) (digital light processor) using DMD (registered trademark) (digital mirror device).

  In the projection type projector apparatus according to the above technical field, it is required to illuminate an image with a uniform and sufficient color rendering on a rectangular screen. In order to meet such demands, a short arc type ultra-high pressure mercury lamp with a mercury vapor pressure of 150 atm or higher is used as a light source built in the apparatus, and emits light forward efficiently. Therefore, concave reflecting mirrors are used in combination.

  In recent years, in such a projector apparatus, there is a request from a user not only to be permanently installed in a conference room or the like but also to be easily carried and used in various places, and the projector apparatus has become smaller than before. As the projector apparatus is further reduced in size, the reflecting mirror in the light source apparatus is also particularly reduced in size.

  However, if the concave reflecting mirror is simply reduced in size, the effective reflection area of the concave reflecting mirror is reduced, and the luminous flux emitted from the light source device is reduced. Moreover, in recent years, in addition to miniaturization of the light source device as described above, the screen illuminance of the projector device has been required to be higher than before. I can't respond.

  Thus, for example, techniques described in Patent Document 1 and Patent Document 2 are known as techniques that can make the reflecting mirror compact without impairing the utilization efficiency of the light beam collected by the reflecting mirror.

  Patent Document 1 (Japanese Patent No. 3557988) has a first reflecting surface having an elliptical surface or a parabolic surface that forms a light emission port, and a substantially spherical surface located behind the first reflecting surface. A light source device including a concave reflecting mirror including a second reflecting surface and a third reflecting surface having an elliptical surface or a parabolic surface located behind the second reflecting surface is disclosed ( Prior art 1).

  In Patent Document 2 (Japanese Patent Application Laid-Open No. 2002-237202), a reflector is composed of two reflecting mirrors arranged in front and back in the optical axis direction, and the reflecting mirror arranged in front is an ellipsoid or a parabola. There has been disclosed a reflector-equipped lamp having a surface and a reflector disposed behind has a spherical surface (prior art 2).

In both of these prior arts 1 and 2, the reflecting mirror having a spherical surface arranged in the rear direction is configured to reflect toward the original arc center when light from the arc center of the light source lamp is incident. The light is returned to the light and then incident on a reflecting surface made of an ellipse or a paraboloid arranged in front of the light to obtain predetermined condensed light. By having such a configuration, it is possible to increase the utilization efficiency of light emitted from the light source lamp, and as a result, it is possible to reduce the size of the concave reflecting mirror and the light source device in which the concave reflecting mirror and the lamp are combined. It becomes possible.
Japanese Patent No. 3557988 JP 2002-237202 A

However, the above prior art has a problem that it is difficult to manufacture and lacks versatility.
First, the prior art 1 will be described with reference to FIG. In this technique, the first reflecting surface 71, the second reflecting surface 72, and the third reflecting surface 73 are arranged in this order from the front of the optical axis L (on the side of the light projection port) in order of the concave reflecting mirror base 70A. It is formed on the inner surface. The first reflecting surface 71 and the third reflecting surface 73 are spheroids (or rotating paraboloids), and the second reflecting surface 72 is substantially spherical. Then, the positions of the first focal points of the first and third reflecting surfaces 71 and 73 coincide with the center position of the substantially spherical surface of the second reflecting surface 72, and this is the discharge lamp mounted on the reflecting mirror 70. It is configured to coincide with approximately the center of 60 arcs.
When the first and third reflecting surfaces 71 and 73 are elliptical surfaces, the light incident on the first reflecting surface 71 from the first focal point F _{1 at} the center of the arc passes through the optical path (A) and the second focal point F. _2, light incident from the first focal point F ₁ to the second reflecting surface 72, after returning to the first focal point F _1, a first reflecting surface is reflected in the symmetrical positions around the optical axis L 71 incident on and is reflected towards the second focal point F ₂ through the optical path (b). The light incident from the first focal point F ₁ to the third reflecting surface 73 is reflected toward a second focus F ₂ via the optical path (c).

  The concave reflecting mirror 70 having such a plurality of reflecting surfaces (71, 72, 73) is, for example, made of glass having high heat resistance as the base 70A, and predetermined by a technique such as hot pressing using a molding die. After forming the reflective surface, a visible light reflective film is formed and completed. As the reflective film, a dielectric multilayer film that is transparent to light having wavelengths in the infrared and ultraviolet regions and has a high reflectance with respect to visible light is preferably selected.

  However, it has been found that when physical vapor deposition (PVD) such as vacuum vapor deposition or sputtering is employed as a method for forming the reflective film, a film is not formed on the second reflective surface (72).

This is because the second reflecting surface 72 is substantially spherical, and the curved surface is formed substantially parallel to the optical axis L of the reflecting mirror 70 at the opening side (first reflecting surface 71 side). When a film is formed by vacuum deposition or sputtering, it is difficult to reach the second reflecting surface because the film forming material from the vapor deposition source or the sputtering source is shielded by the first reflecting surface. This is because the film becomes non-uniform and a film having a sufficient thickness for reflection cannot be formed.
As a result, the film thickness distribution is significantly different from the first reflecting surface 71 and the second reflecting surface 72, and a desired reflectance cannot be obtained at the second reflecting surface 72.

  On the other hand, in the prior art 2, since the reflecting mirror having an elliptical surface or a paraboloid and the reflecting mirror having a spherical surface are formed separately, films can be individually formed by vacuum deposition or sputtering. In this respect, it is considered superior to the prior art 1.

  However, in the prior art 2, it is very difficult to make the focal point of each reflector coincide with the arc center of the lamp in the assembling process after the individual reflectors are manufactured, and the intended utilization efficiency improvement effect is obtained. Is difficult. Further, since two reflecting mirrors are formed for one light source device, there is a problem that productivity is poor and cost is increased.

Therefore, the problem to be solved by the present invention is that in the reflecting mirror in which the spherical second reflecting surface is formed after the first reflecting surface, the reflecting film can be reliably formed as expected, and different reflecting surfaces can be formed. To provide a method for manufacturing a concave reflector that can adjust the focal position even on a surface very easily, achieve high light utilization efficiency, and can be manufactured at low cost with good productivity. It is in.
It is another object of the present invention to provide a concave reflecting mirror mold in which a concave reflecting mirror can be easily manufactured.
Further, in the concave reflecting mirror in which the spherical second reflecting surface is formed subsequent to the first reflecting surface, the reflecting film can be reliably formed as expected, and even if the reflecting surface is different, the focal position can be changed. An object of the present invention is to provide a concave reflecting mirror that can be adjusted very easily and realize high light utilization efficiency, and to provide a light source device using the concave reflecting mirror.

In order to solve the above problems, a method of manufacturing a concave reflecting mirror according to the present invention includes at least a first reflecting surface and a second reflecting surface configured by a rotating surface centered on an optical axis, and a first reflecting surface. The first and second reflecting surfaces are arranged in this order in the direction of the optical axis, and the manufacturing method of the glass concave reflecting mirror,
A step of integrally forming the base of the concave reflecting mirror by hot pressing so that a split margin is formed between the first reflecting surface portion and the second reflecting surface portion;
Cutting the base at a split margin to divide the base in the longitudinal direction of the optical axis;
Forming a light reflection film on each of the first reflection surface portion and the second reflection surface portion, and configuring the first reflection surface and the second reflection surface;
And combining the substrates again so that the first reflecting surface and the second reflecting surface are continuous.

Further, the mold according to the present invention has at least a first reflecting surface and a second reflecting surface constituted by a rotating surface with the optical axis as the center, and the first and second reflecting surfaces are this. It is a mold for glass shaping that manufactures a concave reflector made of glass that is sequentially arranged from the front in the optical axis direction,
A bottom mold in which the outer surface shape of the concave reflecting mirror is formed on the inner surface thereof, a ring mold disposed along the opening edge of the bottom mold, and a plunger having a predetermined reflecting surface shape formed on the outer surface thereof The plunger is configured to have a substantially cylindrical or substantially conical portion between the first reflecting surface forming portion and the second reflecting surface forming portion.
Also, in the glass mold for concave reflecting mirror, the bottom mold includes means for partially forming the outer peripheral portion of the concave reflecting mirror corresponding to the division allowance into a substantially cylindrical shape or a substantially conical shape. It is characterized by having.

The concave reflecting mirror according to the present invention has first and second reflecting surfaces composed of different curved surfaces constituted by a rotating surface with the optical axis as the center, and the first and second reflecting surfaces are the same. A concave reflector that is disposed in the optical axis direction in order to form a concave surface as a whole,
The substrate of the concave reflecting mirror is made of glass, and the substrate has a dividing portion between the first reflecting surface and the second reflecting surface.
The light source device according to the present invention includes a short arc type discharge lamp provided in a discharge vessel so that a pair of discharge electrodes face each other, and the discharge lamp in a state where the arc direction of the discharge lamp coincides with the optical axis. It is arranged so as to surround, and consists of a concave reflecting mirror having a light projection port in the front,
The concave reflecting mirror has first and second reflecting surfaces composed of different curved surfaces formed by rotating surfaces around the optical axis, and the first and second reflecting surfaces are arranged in this order in the optical axis direction. A concave reflecting mirror having a concave shape as a whole,
The substrate of the concave reflecting mirror is made of glass, and the substrate has a dividing portion between the first reflecting surface and the second reflecting surface.

(1) According to the method for manufacturing a concave reflecting mirror according to the present invention, the base of the concave reflecting mirror is divided into a first reflecting surface and a second reflecting surface, and then a reflecting film is applied to each base. Therefore, the reflective film can be formed with the desired reflection characteristics. Moreover, since it is originally composed of an integral glass substrate, when the substrates are combined again, the focal points of the first reflecting surface and the second reflecting surface coincide with each other. Positioning is easy and high light utilization efficiency can be realized.
In particular, in the hot pressing of the glass substrate, since the split margin is formed between the first reflecting surface portion and the second reflecting surface portion, the focal position is not shifted even by the splitting.

(2) Moreover, according to the glass concave-surface reflecting mirror mold according to the present invention, in the plunger that forms the reflecting surface of the concave reflecting mirror, the first reflecting surface forming portion and the second reflecting surface forming portion. Since a means for forming a division allowance is provided between the two, a concave reflecting mirror substrate in which the focal position is not shifted even by the division can be reliably provided.
Further, the bottom mold for forming the outer surface of the concave reflecting mirror is provided with means for forming the outer surface of the concave reflecting mirror into a substantially cylindrical shape on the outer periphery of the concave reflecting mirror corresponding to the division allowance. When the substrate is cut, it is easy to detect the division allowance from the outside, and the cutting edge of a grinder or the like can be stabilized and the yield can be improved.

(3) The reflecting mirror base has a split portion, that is, by forming an integral concave reflecting mirror after the base is split, the reflecting surfaces of both the first reflecting surface and the second reflecting surface are formed. On the other hand, it is possible to reliably form a reflective film, to form a reflective surface having the desired reflection characteristics, to improve the light utilization efficiency, and to produce a concave surface that is easy to manufacture and can be produced at low cost. A reflector is obtained.
Furthermore, by incorporating a light source lamp into the concave reflecting mirror, a light source device suitable for a projector device can be obtained.

Hereinafter, the manufacturing method of the concave reflecting mirror according to the present invention will be described based on examples.
FIG. 1 is an explanatory view of a light source device comprising a concave reflecting mirror and a light source lamp according to the present invention, and is a sectional view cut along a plane including the optical axis of the reflecting mirror. FIG. 2 is a mold for forming a substrate of a concave reflecting mirror according to the present invention, and is a plan view of a plunger and a sectional view of a bottom mold. FIG. 3 is a view of pressing glass using the mold according to the present invention. It is explanatory drawing which shows a process. FIG. 4 is a diagram for explaining a process of manufacturing the final product of the concave reflecting mirror from the concave reflecting mirror substrate manufactured from the mold according to the present invention.

<Light source device>
First, the final form of the concave reflecting mirror according to the embodiment of the present invention will be described with reference to FIG.
(1) Light source lamp The light source lamp 10 is preferably a short arc type discharge lamp such as an ultra-high pressure mercury lamp. As the lighting method, either a direct current or an alternating current lamp can be used, but here, an example of an ultra high pressure mercury lamp of an alternating current lighting method will be described.
The arc tube of the light source lamp 10 is made of a light-transmitting material such as quartz glass provided with a substantially spherical arc tube portion 11 and a cylindrical sealing portion 12 continuous at both ends of the arc tube portion 11. A pair of electrodes 13 and 14 made of tungsten are arranged in the inner space of the arc tube portion 11 so as to face each other. One end portion of a metal foil 15 used for sealing is joined to the base end portions of the electrodes 13 and 14 and is hermetically embedded and sealed with glass constituting the sealing portion 12. One end portion of the external lead 16 is joined to the other end portion of the metal foil 15, and the other end portion extends outward and protrudes outside the sealing portion 12.
Further, mercury, a halogen gas, and a rare gas as a luminescent material are sealed in the inner space of the arc tube portion 11. Mercury interior mercury vapor pressure is more than 150 atm (preferably at least 200 atmospheres) and so as 0.15 mg / mm ³ or more (preferably 0.20 mg / mm ³ or more) at the time of lighting is encapsulated. The halogen gas is intended to prevent blackening of the inner wall of the arc tube portion 11 due to the halogen cycle, and is enclosed by 10 ⁻⁶ μmol / mm ³ to 10 ⁻² μmol / mm ³ . The rare gas is filled with, for example, about 0.0133 MPa of argon gas for the purpose of improving the starting aid.

(2) Concave Reflective Mirror The concave reflecting mirror 20 includes a first reflecting mirror base 201 having a light emission port 21 and a second reflecting mirror base 202 connected to the rear end of the base 20A. The base body 20A is formed by joining a glass molded body, which is integrally formed in this shape substantially by hot press molding of glass, at the dividing portion 27 after being cut at a plane perpendicular to the optical axis. .

On the inner surface of the concave reflecting mirror 20, a portion corresponding to the first reflecting mirror base 201 is formed by a spheroidal surface having the optical axis L as the rotation axis, and a dielectric multilayer film is formed to form the first. The reflecting surface 22 is configured. The first focal point of the first reflecting surface 22 coincides with the center position of the arc in the light source lamp 10, and the second focal point coincides with a condensing part of an optical element (not shown) disposed in front of the light source device 100. .
A second reflecting surface 23 is formed so as to be optically continuous with the first reflecting surface 22. The second reflecting surface 23 is formed on the inner surface of the second reflecting mirror base 202, and forms a substantially spherical reflecting surface whose center position coincides with the arc center of the light source lamp 10. The second reflecting surface 23 is not necessarily a perfect spherical shape because the lens effect in the arc tube portion 11 is taken into consideration, but is composed of a reflecting surface that returns incident light to the focal point.

A third reflecting surface 24 is formed continuously with the second reflecting surface 23. The third reflecting surface 24 is a spheroidal surface having the optical axis L as the rotation axis, the first reflecting surface, the first focal point, and the second focal point coincide with each other. Light that leaks slightly in between is reflected forward.
The third reflecting surface 24 is also formed on the second reflecting mirror base 202.

As described above, in the concave reflecting mirror 20 according to the present invention, the base 20A is formed by integrally forming a glass molded body substantially in this shape by hot press molding of glass, and then is a surface perpendicular to the optical axis at the dividing portion 27. Can be formed in a separate process between the reflecting film (22) of the first reflecting mirror base 201 and the reflecting film (23, 24) of the second reflecting mirror base 202. The reflective film can be formed so as to obtain an ideal reflectance.
In addition, the first reflecting mirror base 201 and the second reflecting mirror base 202 are configured integrally with the same mold, and can be easily matched in focus position by joining at the dividing portion 27. Therefore, a concave reflecting mirror with good productivity and high light collection rate can be obtained.
Therefore, in spite of the concave reflecting mirror 20 having a plurality of reflecting surfaces, the alignment efficiency with respect to the light source lamp 10 is easy and the productivity is good, and the light utilization efficiency is remarkably high. The light source device 100 is obtained.

<Manufacturing method>
Subsequently, a process of manufacturing the concave reflecting mirror will be described in detail with reference to FIGS.
(1) Mold for Glass Concave Reflector FIG. 2 is an explanatory diagram of a mold for forming a substrate of a concave reflector according to the present invention.
In the figure, a mold 40 for hot-pressing glass has a bottom mold (body mold) 43 that opens upward and has an outer surface shape of a concave reflecting mirror formed on the inner surface thereof, along the upper opening edge. The ring mold 42 is arranged, and a plunger (arrow type) 41 having a predetermined reflecting surface shape formed on the outer surface thereof.

  On the outer surface of the plunger 41, a first curved surface portion 411 for forming a first reflecting surface, a second reflecting surface and a third reflecting surface formed on the inner surface of the concave reflecting mirror, A curved surface portion 412 and a third curved surface portion 413 are provided. And between the 1st curved surface part 411 and the 2nd curved surface part 412, it is substantially circular so that the diameter of the plunger 41 may become substantially constant corresponding to the division part (27) of a concave reflecting mirror (20). The division allowance forming portion 41A formed in a columnar shape is formed in a predetermined length in the axial direction, for example, in a range of 0.1 mm to 7 mm. In the division allowance forming portion 41A, a cylindrical shape is most preferable, but a truncated cone shape is also possible. In this case, the cone angle is preferably 7 degrees or less.

On the other hand, the bottom mold 43 has a barrel forming portion 43A having an inner diameter substantially constant at a location corresponding to the outer periphery of the split allowance forming portion 41A of the plunger 41, rather than the total length of the split allowance forming portion 41A. It is provided over a long range. By forming the inner diameter constant in this way, the glass molded body obtained by press molding is formed with a substantially cylindrical portion having a constant outer diameter at the portion corresponding to the division allowance. Thus, a body part that is easy to enter a blade such as a grinder is formed. The body portion may be a columnar shape or a truncated cone shape, and when formed in the truncated cone shape, the cone angle is preferably 7 degrees or less.
Note that the length of the trunk portion forming portion 43A is longer than the split margin forming portion 41A of the plunger 41, and is 2.1 mm to 9 mm, for example.

(2) Hot pressing of glass Using the above-described mold 40 according to the present invention, glass is press-molded as shown in FIGS.
First, as shown in FIG. 3A, a heated and soft glass lump called a gob 45 is quantitatively dropped and introduced into the inside of the bottom mold 43. The plunger 41 is inserted with the ring mold 42 placed on the top of the bottom mold 43. Subsequently, as shown in FIG. 3B, the plunger 41, the ring mold 42, the bottom mold 43, and the gob 45 are interposed. The plunger 41 is inserted under pressure until there is no gap.
When the gob 45 is cooled and loses its fluidity, the mold is removed and the glass mold 50 is gradually cooled to complete cooling, and then a glass molded body 50 for a concave reflector is completed as shown in FIG.

In the glass molded body 50, a split margin 501 is formed on the inner surface forming the reflecting surface, and a body portion 502 is formed on the outer surface. The division allowance 501 takes into account the thickness into which a grinder blade or the like enters when the glass molded body 50 is cut, and if the division allowance 501 is not formed, the first concave reflecting mirror finally obtained is obtained. Since the gap between the reflecting surface and the second reflecting surface becomes extremely discontinuous, there is a possibility that the reflection efficiency is lowered.
The body portion 502 is provided to correctly insert a grinder blade or the like in the direction perpendicular to the optical axis when cutting. In addition, by forming larger than the width | variety of the division allowance 501, the division allowance 501 formed inside even if it is from the outer side of a glass molded object becomes easy to visually recognize, and it can cut | disconnect in a regular position.
Needless to say, these molds are formed in advance with a degree of shrinkage due to the sink of glass, and a predetermined reflecting surface is formed after the mold is solidified. It is also natural that the focal position of each reflecting surface is designed in consideration of the formation of the division allowance 501.

(3) Division, Formation of Reflecting Film and Assembly Process The manufacturing process of the concave reflecting mirror according to the present invention will be described with reference to FIG.
Fig.4 (a) is the glass forming body 50 obtained by the hot press process of the said glass. As described above, the division allowance 501 is formed on the inner surface, and the body portion 502 is formed on the outer surface. The glass molded body 50 is cut in the vertical direction on the paper surface at the division allowance 501.
After this, although it is not an essential step, the cross section of the division allowance 501 may be polished and cleaned. Further, the residual mark of the inner division allowance 501 can be removed or reduced by polishing. In addition, since the width | variety of the trunk | drum 502 is formed in the outer surface of a base | substrate larger than the width | variety of the division | segmentation allowance 501 of an inner surface, the trace of the trunk | drum 502 is formed reliably.
FIG. 4B shows a glass molded body after cutting, whereby a first reflecting mirror base 201 and a second reflecting mirror base 202 are configured. Reference numerals 27a and 27b denote division units.

Subsequently, as shown in FIG. 4C, reflection films R1 and R2 are formed on the first and second reflecting mirror bases 201 and 202, respectively. This reflective film is a dielectric multilayer film that is transmissive to infrared light and reflective to visible light. For example, a TiO ₂ vapor deposition film and a SiO ₂ vapor deposition film are alternately formed. It is a multilayer film having a total film thickness of 0.05 μm to 0.5 μm.
As described above, since the first and second reflecting mirror bases 201 and 202 are divided, for example, even when a film forming method such as vacuum deposition or sputtering is used, the deposition source or the sputtering source is on the reflecting surface. Therefore, it is possible to form a reflecting surface having an intended reflecting function.

Thereafter, as shown in FIG. 4 (d), the divided reflectors 27a and 27b are combined to complete the concave reflecting mirror 20.
Note that the first and second reflecting mirror bases 201 and 202 are coupled to each other at the edge of the light projection port of the first reflecting mirror base and the hole of the second reflecting mirror base. Covering the mounting frame and placing the first reflecting mirror base and the second reflecting mirror base in contact with the split part, connecting the fixing arm with a tension spring to the mounting frame, the first reflection For example, a method of fixing the mirror base and the second reflecting mirror base by elastically urging them in the directions of each other can be employed.

An example of the specification of the concave reflecting mirror manufactured by the above-described concave reflecting mirror manufacturing method will be shown below.
(1) First reflector substrate (201)
The first reflecting surface (22) has an ellipsoidal surface having a major axis of 34.05 mm and a minor axis of 19.29 mm, and the light emitting port (21) has an opening diameter of 37.2 mm. The total length in the optical axis direction is 18.4 mm.
(2) Second reflector substrate (202)
The second reflecting surface (23) has a spherical surface with a radius of 11.4 mm. The total length in the optical axis direction is 4.16 mm.
The third reflecting surface (24) has an elliptical surface with a major axis of 35.05 mm and a minor axis of 22.29 mm, and the opening diameter of the hole portion (25) is 10 mm. The total length in the optical axis direction is 3.36 mm.

According to the manufacturing method of the concave reflecting mirror according to the present invention described above, it is optimal for the first reflecting mirror substrate having the first reflecting surface and the second reflecting mirror substrate having the second reflecting surface because they are separated. A dielectric multilayer film can be formed by physical vapor deposition such as vacuum vapor deposition or sputtering under the above conditions, and a concave reflecting mirror that can obtain optimum reflection characteristics can be provided. In addition, the first reflecting mirror base and the second reflecting mirror base are integrally formed by hot pressing, and the first reflecting surface of the first reflecting mirror base and the second reflecting mirror base of the second reflecting mirror base are the same. Since it has been cut after providing a dividing margin at the boundary between the two reflecting surfaces, when it is joined again, the first reflecting surface of the first reflecting mirror substrate and the second reflecting surface of the second reflecting mirror substrate The boundary can be easily matched, and at the same time, the focal position of the first reflecting surface can coincide with the second focal position.
Further, according to the concave reflecting mirror mold according to the present invention, the work for dividing the first reflecting mirror base having the first reflecting surface and the second reflecting mirror base having the second reflecting surface is performed. A glass molded body can be obtained in which the process can be performed easily and reliably.
As a result, it is possible to obtain a concave reflecting mirror that has a high reflection efficiency on the reflecting surface and is easy to manufacture. Further, by combining the concave reflecting mirror and a light source lamp composed of a short arc type discharge lamp, a projector device is obtained. It is possible to provide an optimal light source device for use.

It is explanatory drawing of the light source device which consists of a concave reflecting mirror and a light source lamp based on this invention, and is sectional drawing cut | disconnected by the surface containing the optical axis of a reflecting mirror. It is a metal mold | die for forming the base | substrate of the concave reflecting mirror which concerns on this invention, and is a plunger top view and sectional drawing of a bottom mold. It is explanatory drawing which shows the process of pressing glass using the metal mold | die which concerns on this invention. It is a figure explaining the process of manufacturing the final product of a concave reflector from the concave reflector base manufactured from the metal mold | die which concerns on this invention. It is sectional drawing of the longitudinal direction which shows schematic structure of the conventional light source device.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Light source device 1 Discharge lamp 11 Arc tube part 12 Sealing part 13, 14 Electrode 15 Metal foil 16 External lead 20 Concave reflector 20A Base 201 First reflector base 202 Second reflector base 21 Light emission port 22 First One reflecting surface 23 Second reflecting surface 24 Third reflecting 25 Hole portion 26 Adhesive 27 Dividing portion 40 Manufacturing mold and concave reflecting mirror 41 Plunger (arrow-shaped)
42 Ring mold 43 Bottom mold (trunk mold)
45 Gob (softened glass lump)
50 Glass molded body

Claims (5)

Glass having at least a first reflecting surface and a second reflecting surface constituted by a rotating surface centered on the optical axis, and the first and second reflecting surfaces arranged in this order in the optical axis direction A method of manufacturing a concave reflecting mirror,
A step of integrally forming the base of the concave reflecting mirror by hot pressing so that a split margin is formed between the first reflecting surface portion and the second reflecting surface portion;
Cutting the base at a split margin to divide the base in the longitudinal direction of the optical axis;
Forming a light reflection film on each of the first reflection surface portion and the second reflection surface portion, and configuring the first reflection surface and the second reflection surface;
And a step of recombining and integrating the substrates so that the first reflecting surface and the second reflecting surface are continuous. Glass having at least a first reflecting surface and a second reflecting surface constituted by a rotating surface centered on the optical axis, and the first and second reflecting surfaces arranged in this order in the optical axis direction It is a mold for glass shaping to produce a concave reflector made of metal,
A bottom mold in which the outer surface shape of the concave reflecting mirror is molded on the inner surface thereof, a ring mold disposed along the opening edge of the bottom mold, and a plunger having a predetermined reflecting surface shape formed on the outer surface thereof A glass concave surface, wherein the plunger is provided with a substantially cylindrical or substantially truncated cone portion between the first reflecting surface forming portion and the second reflecting surface forming portion. Reflector mold. The glass concave reflector mold according to claim 2,
3. The glass according to claim 2, wherein the bottom mold is provided with means for partially forming the outer peripheral portion of the concave reflecting mirror corresponding to the division allowance into a substantially cylindrical shape or a substantially truncated cone shape. Mold for concave reflector made of metal. The first and second reflecting surfaces are composed of different curved surfaces composed of rotating surfaces around the optical axis, and the first and second reflecting surfaces are arranged in this order in the optical axis direction. A concave reflecting mirror having a concave shape,
The concave reflecting mirror is characterized in that the base of the concave reflecting mirror is made of glass, and the base has a dividing portion between the first reflecting surface and the second reflecting surface. A short arc type discharge lamp provided with a pair of discharge electrodes facing each other in the discharge vessel, and disposed so as to surround the discharge lamp in a state where the optical axis coincides with the arc direction of the discharge lamp. It consists of a concave reflector with a projection port,
The concave reflecting mirror has first and second reflecting surfaces composed of different curved surfaces formed by rotating surfaces around the optical axis, and the first and second reflecting surfaces are arranged in this order in the optical axis direction. A concave reflecting mirror having a concave shape as a whole,
The light source device characterized in that the base of the concave reflecting mirror is made of glass, and the base has a dividing portion between the first reflecting surface and the second reflecting surface.

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