JP2007256423A - Method for manufacturing reflector, and light source apparatus and projector - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a reflector (sub-mirror) manufacturing method for manufacturing a reflector (sub-mirror) by an air-pressure molding method, in which the reflector (sub-mirror) can be prevented from being cracked or broken. <P>SOLUTION: The reflector (sub-mirror) manufacturing method comprises: a tubular member preparation process; an expansion part formation process for forming an expansion part partially expanded on a tubular member by heating the tubular member, charging the heated tubular member into a molding die, and then applying inner pressure by inert gas so that the inner surface shape of the portion in the tubular member corresponds to the reflection surface of the reflector (sub-mirror); a reflector base material formation process (sub-mirror base material formation process) for forming a reflector base material (sub-mirror base material) by cutting off the tubular member on which the expansion part is formed; a micro-crack removing process for removing micro-cracks generated on the cutting surface of the reflector base material (sub-mirror base material); and a reflection layer formation process for forming a reflection layer on a portion, which becomes a reflection surface, out of the reflector base material (sub-mirror base material). <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a reflector manufacturing method, a light source device, and a projector.

Conventionally, a light source device including a secondary mirror is known as a light source device used for a projector (
For example, see Patent Document 1. As a method for manufacturing such a secondary mirror, a method of manufacturing the secondary mirror by a pressure forming method is known (for example, see Patent Document 2).
The conventional secondary mirror manufacturing method includes a tubular member preparation step of preparing a tubular member made of the material of the secondary mirror, and after the tubular member is heated and placed in a mold, a part of the inner surface of the tubular member has two inner shapes. An inflating part forming step for forming an inflating part by inflating a part of the tubular member by applying an internal pressure with an inert gas so as to form a reflecting surface when the secondary mirrors face each other; A secondary mirror base material forming step for forming two secondary mirror base materials by cutting the formed tubular member, and a reflective layer formation for forming a reflective layer on a portion of the inner surface of the secondary mirror base material that becomes a reflective surface Process.

According to the conventional method for manufacturing a secondary mirror, a tubular member is formed by applying an internal pressure with an inert gas so that the shape of a part of the inner surface of the tubular member becomes the shape of a reflecting surface when the two secondary mirrors face each other. Since a part of the member is inflated to form the inflatable portion, a mold for forming the reflecting surface of the secondary mirror is not necessary. For this reason, even if the continuous production quantity of the secondary mirror increases, the surface of the mold does not wear or the secondary mirror material does not adhere to the surface of the mold, so the surface condition of the mold deteriorates. Therefore, the characteristics of the reflecting surface of the secondary mirror to be manufactured are not deteriorated, so that the light use efficiency is not reduced and the manufacturing cost is not increased. As a result, an excellent secondary mirror having high light utilization efficiency can be manufactured at a low manufacturing cost.
Further, according to the conventional method of manufacturing the secondary mirror, the inner surface of the tubular member comes into contact with only the inert gas, so that a smooth reflective surface with extremely small surface roughness can be obtained as the reflective surface of the secondary mirror. .
Therefore, according to the conventional secondary mirror manufacturing method, it is possible to manufacture an inexpensive secondary mirror that is excellent in surface roughness and light utilization efficiency.

JP-A-8-31382 (FIG. 1) International Publication No. 2005/017406 Pamphlet (Figure 2)

However, in the conventional method for manufacturing a secondary mirror, the secondary mirror base material is formed by cutting the tubular member in the secondary mirror base material forming step. Sub-mirrors that have cracks) may be produced. When a secondary mirror in which such microcracks have occurred is used in a light source device, thermal stress is generated inside the secondary mirror due to the high temperature around the secondary mirror, and microcracks are caused by thermal stress. As a result of growing,
The secondary mirror may be chipped or broken.

Such a problem does not occur only when the secondary mirror is manufactured by the atmospheric pressure forming method, but also occurs when the reflector used for the light source device is manufactured by the atmospheric pressure forming method. That is, it is a problem that generally occurs when manufacturing a reflecting mirror including a reflector and a secondary mirror.

Therefore, the present invention has been made to solve such a problem, and in the reflector manufacturing method for manufacturing a reflector by an atmospheric pressure forming method, it is possible to prevent the reflector from being chipped or broken. An object of the present invention is to provide a method for manufacturing a reflecting mirror. Moreover, it aims at providing the light source device provided with the reflector or submirror manufactured by the manufacturing method of such the outstanding reflector. Furthermore, it aims at providing a projector provided with such an excellent light source device.

The manufacturing method of the reflecting mirror of this invention is a manufacturing method of the reflecting mirror used for the light source device provided with the arc tube which has a light emission part, and the reflective mirror which has the reflective surface which reflects the light from the said light emission part in a predetermined direction. A tubular member preparing step of preparing a tubular member made of the material of the reflecting mirror, and after heating the tubular member into a mold, a part of the inner surface shape of the tubular member is reflected by the reflecting mirror. An inflatable portion forming step of forming an inflatable portion by inflating a part of the tubular member by applying an internal pressure with an inert gas so as to have a shape corresponding to the surface; and the tubular member in which the inflatable portion is formed A reflecting mirror base material forming step for forming a base material of the reflecting mirror, a micro crack removing step for removing micro cracks generated on a cutting surface of the base material of the reflecting mirror, and Base material Characterized in that it comprises an inner said reflecting layer forming step of forming a reflective layer on the portion to be the reflecting surface.

For this reason, according to the manufacturing method of the reflecting mirror of the present invention, since the reflecting mirror is manufactured by the atmospheric pressure forming method, it is possible to manufacture an inexpensive reflecting mirror having excellent surface roughness and light utilization efficiency.

Moreover, according to the manufacturing method of the reflecting mirror of the present invention, microcracks that may occur on the cut surface of the base material of the reflecting mirror can be removed in the microcrack removing step. Even if thermal stress occurs, it is possible to prevent the reflecting mirror from being broken or cracked.

In this specification, “microcrack” refers to a microcrack that occurs in the cut surface of the base material of the reflector, and means that the tip is a V-shaped groove.

In the manufacturing method of the reflective mirror of this invention, it is preferable to perform an etching process with respect to the cut surface of the base material of the said reflective mirror in the said microcrack removal process.

By adopting such a method, even if a microcrack occurs on the cut surface of the base material of the reflecting mirror, it is possible to make the tip portion of the microcrack into a U shape instead of a V shape. It becomes. That is, by performing the etching process, it is possible to remove the microcracks by making the microcracks that may occur on the cut surface of the base material of the reflecting mirror into a U-shaped groove. For this reason, as a result of suppressing the progress of cracks, even if thermal stress is generated inside the reflecting mirror, the reflecting mirror can be prevented from being chipped or cracked.

In the manufacturing method of the reflective mirror of this invention, it is preferable to irradiate a laser beam with respect to the cut surface of the base material of the said reflective mirror in the said micro crack removal process.

By adopting such a method, even if microcracks are generated on the cut surface of the base material of the reflector, the base material of the reflector is cut by partially melting the part including the microcracks. Microcracks that may occur on the surface can be eliminated. As a result, even if thermal stress is generated inside the reflecting mirror, the reflecting mirror can be prevented from being broken or broken. In addition, if laser light is irradiated only to the cut surface of the base material of a reflective mirror, unlike the case of what is called a fire polish, the shape accuracy of a reflective mirror will not be impaired.

In the manufacturing method of the reflective mirror of this invention, it is preferable to grind | polish with respect to the cut surface of the base material of the said reflective mirror in the said microcrack removal process.

By setting it as such a method, even if the microcrack has generate | occur | produced in the cut surface of the base material of a reflective mirror, it becomes possible to remove the part containing the said microcrack collectively. As a result, even if thermal stress is generated inside the reflecting mirror, the reflecting mirror can be prevented from being broken or broken.

In the reflecting mirror manufacturing method of the present invention, in the expanding portion forming step, the inner surface shape of a part of the tubular member is the shape of the reflecting surface when two reflecting mirrors face each other. It is preferable to form an inflating part and form the two reflecting mirrors in the reflecting mirror substrate forming step.

By adopting such a method, it becomes possible to form a reflecting mirror substrate having the same shape from a single tubular member, so that it is possible to reduce the manufacturing cost when manufacturing the reflecting mirror. .

The light source device of the present invention is disposed on the side of one sealing part in the arc tube, the arc tube having a light bulb and a pair of sealing parts extending on both sides of the tube part, A light source device comprising a reflector that reflects light from a light emitting unit toward an illuminated area, wherein the reflector is a reflector manufactured by the method of manufacturing a reflector according to the present invention described above. To do.

For this reason, the light source device of the present invention is a high-quality light source device including a reflector that is excellent in surface roughness and light utilization efficiency, is inexpensive, and is suppressed from being broken or cracked.

The light source device of the present invention is disposed on the side of one sealing part in the arc tube, the arc tube having a light bulb and a pair of sealing parts extending on both sides of the tube part, A reflector that reflects light from the light emitting portion toward the illuminated region side, and a reflection that is disposed on the other sealing portion side of the arc tube and reflects light from the light emitting portion toward the bulb portion A light source device including a secondary mirror having a surface, wherein the secondary mirror is a reflective mirror manufactured by the method for manufacturing a reflective mirror of the present invention described above.

For this reason, the light source device of the present invention is a high-quality light source device including a secondary mirror that is excellent in surface roughness and light utilization efficiency and is inexpensive and suppressed from being chipped or broken.

The projector of the present invention includes an illumination device having the above-described light source device of the present invention, an electro-optic modulation device that modulates light from the illumination device according to image information, and light modulated by the electro-optic modulation device. A projection optical system for projecting.

Therefore, the projector according to the present invention is a high-quality projector including the above-described excellent light source device.

Hereinafter, a reflector manufacturing method, a light source device, and a projector according to the present invention will be described based on the embodiments shown in the drawings.

[Embodiment 1]
Embodiment 1 demonstrates the case where the manufacturing method of the reflective mirror of this invention is applied to the manufacturing method of a secondary mirror.
FIG. 1 is a flowchart for explaining a method for manufacturing a secondary mirror according to the first embodiment. 2-4 is a figure which shows typically each process in the manufacturing method of the submirror which concerns on Embodiment 1. FIG. FIG. 2 (a) is a diagram schematically showing the tubular member preparation step, and FIG. 2 (b) and FIG. 2 (c).
FIG. 2 is a diagram schematically showing a tubular member forming step, and FIG. 2D is a diagram schematically showing a tubular member cutting step. 3 (a) is an enlarged view schematically illustrating front of the first end face P ₁ of the secondary mirror substrate 2 for microcrack removing step, FIG. 3 (b) After the microcrack removing step the first end face P ₁ of the secondary mirror substrate 2 is an enlarged view schematically showing. FIG. 4 is a diagram schematically showing the reflective layer forming step.

The manufacturing method of the secondary mirror according to the first embodiment is a manufacturing method of the secondary mirror used in the light source device, and includes a “tubular member preparation step”, an “expansion portion forming step”, a “secondary mirror substrate forming step”, and “micro The “crack removing step” and the “reflective layer forming step” are sequentially performed. Hereinafter, each of these steps will be described sequentially.

1. Tubular member preparation step First, as shown in FIG. 2A and FIG. 1, a tubular member 1 made of the material of the secondary mirror is prepared (FIG. 1).
Step S10).
As the material of the tubular member 1, hard glass or quartz glass can be suitably used. Among these, it is more preferable to use quartz glass. This is because quartz glass has a low coefficient of thermal expansion and no internal strain, so that it is not necessary to perform an annealing process.

2. Expansion part formation process Next, as shown in Drawing 2 (b), tubular member 1 is heated. And as shown in FIG.2 (c), after putting in the shaping | molding die F, the shape of a part of inner surface in the tubular member 1 becomes a shape of a reflective surface when two submirrors are mutually faced, By applying an internal pressure with an inert gas, a part of the tubular member 1 is expanded to form an expanded portion E (step S20 in FIG. 1).
As the inert gas, for example, argon gas or nitrogen gas can be suitably used.

3. Sub-mirror base material formation process Next, tubular member 1 'in which expansion part E was formed is cut with a cutting machine etc. (Step S30 of Drawing 1). Thereby, as shown in FIG.2 (d), the two secondary mirror base materials 2 are formed. In this case, the first end face P _{1 of} each secondary mirror base material 2 becomes the “cut surface of the secondary mirror base material”.

4). Next, the microcrack generated on the _first end face P1 of the secondary mirror base material 2 is removed (step S40 in FIG. 1). In the microcrack removing step, an etching process is performed on the _first end face P ₁ of the secondary mirror base 2.

Here, the micro crack will be described. As shown in FIG. 3A, the _first end face P ₁ in the sub mirror base 2 obtained by performing the above-mentioned “sub mirror base material forming step”, Microcracks (microcracks) a may occur. Such a microcrack a
The tip is a V-shaped groove. For this reason, when the secondary mirror made of the secondary mirror base material 2 in the state where the microcracks a exist is used in the light source device, thermal stress is generated inside the secondary mirror due to the peripheral portion of the secondary mirror becoming high temperature. However, as a result of the growth of microcracks a due to thermal stress, the secondary mirror may be chipped or broken.

Therefore, in the manufacturing method of the secondary mirror according to the first embodiment, the micro-cracks removal step, is set to be the etching process is performed with respect to the first end face P ₁ of Fukukagamimotozai 2. Thus, even microcracks a had occurred on the first end face P ₁ of Fukukagamimotozai 2, by performing the etching process, U-shaped rather than microcracks a V-shaped shape of the tip portion of the (See FIG. 3B). That is, by performing the etching process, it is possible to remove the microcracks by making the microcracks a that may occur on the _first end face P1 of the secondary mirror base material 2 into U-shaped grooves b. Become.

As the etching process, a known etching process may be performed. As an etchant used in the etching process, a NaOH solution set to a predetermined concentration can be suitably used.

5). Reflective layer forming step And, as shown in FIG. 4, the reflective layer R is formed on the portion that becomes the reflective surface of the inner surface P ₃ (see FIG. 2D) of the secondary mirror base 2 (step of FIG. 1). S50).
Examples of the reflective layer R include tantalum oxide (Ta ₂ O ₅ ) and silicon oxide (SiO ₂ ).
A reflective layer made of a dielectric multilayer film can be suitably used.

As described above, the secondary mirror 60 (see FIGS. 7 and 8 shown in Embodiment 4 described later) can be manufactured.

Thus, the manufacturing method of the secondary mirror which concerns on Embodiment 1 is a manufacturing method of the secondary mirror used for a light source device, Comprising: As above-mentioned, a tubular member preparation process, an expansion part formation process, and a secondary mirror base material A formation process, a microcrack removal process, and a reflective layer formation process are included.

For this reason, according to the manufacturing method of the secondary mirror which concerns on Embodiment 1, since a secondary mirror is manufactured by an atmospheric pressure forming method, it becomes possible to manufacture an inexpensive secondary mirror with excellent surface roughness and light utilization efficiency. .

According to the manufacturing method of the secondary mirror according to the first embodiment, the microcracks a that can occur in the cut surface of the Fukukagamimotozai 2 (first end face P ₁ of Fukukagamimotozai _2), Micro Since it can be removed in the crack removing step, it is possible to prevent the secondary mirror from being chipped or cracked even if thermal stress is generated inside the secondary mirror.

In the secondary mirror manufacturing method according to Embodiment 1, in the microcrack removal step,
Since the etching process is performed on the _first end face P1 of the sub-mirror substrate 2, the microcracks can be removed by making the microcracks a U-shaped grooves b as described above. . For this reason, it becomes possible to suppress the progress of cracks. As a result, even if thermal stress is generated inside the secondary mirror, the secondary mirror can be prevented from being chipped or cracked.

Further, in the method for manufacturing the secondary mirror according to the first embodiment, as shown in FIG. 2C, since the outer surface of the tubular member 1 ′ is in contact with the forming die F, the influence of the scratches on the die or the like. Does not appear on the reflecting surface of the secondary mirror. For this reason, there is also an effect that a secondary mirror having stable characteristics from the beginning of manufacture to the end of the mold life can be manufactured.

Moreover, in the manufacturing method of the secondary mirror which concerns on Embodiment 1, in the expansion | swelling part formation process, the one part inner surface shape in the tubular member 1 becomes a shape of a reflective surface when two secondary mirrors mutually face each other. The expansion part E is formed, and two secondary mirror base materials 2 are formed by cutting the tubular member 1 ′ formed with the expansion part E in the secondary mirror base material forming step. For this reason, since it becomes possible to form the secondary mirror base material 2 of the same shape from the one tubular member 1, there also exists an effect that the manufacturing cost at the time of manufacturing a secondary mirror can be reduced.

[Embodiment 2]
FIG. 5 is a flowchart for explaining the method for manufacturing the secondary mirror according to the second embodiment.
The manufacturing method of the secondary mirror according to the second embodiment basically includes the same steps as the manufacturing method of the secondary mirror according to the first embodiment, but the contents of the microcrack removal process are the same as those of the secondary mirror according to the first embodiment. It is different from the manufacturing method.

In other words, in the method for manufacturing the secondary mirror according to the second embodiment, the illustration is omitted, but in the microcrack removing step, the first end face P _{1 of the} secondary mirror base 2 is irradiated with laser light. (Step S42 in FIG. 5).

Thus, even if the microcracks a had occurred on the first end face P ₁ of Fukukagamimotozai 2, by melting the portion including the microcracks a partially, microcracks a
Can be eliminated. As a result, even if thermal stress is generated inside the secondary mirror, it is possible to suppress the secondary mirror from being chipped or cracked. Note that if the laser beam is irradiated only on the first end face P _{1 of} the secondary mirror base material 2, unlike the case of so-called fire polishing, the shape accuracy of the secondary mirror is not impaired.

The manufacturing method of the secondary mirror according to the second embodiment is a point other than the content of the microcrack removing step.
Since the same process as the manufacturing method of the submirror which concerns on Embodiment 1 is included, it has an applicable effect as it is among the effects which the manufacturing method of the submirror which concerns on Embodiment 1 has.

[Embodiment 3]
FIG. 6 is a flowchart for explaining the method for manufacturing the secondary mirror according to the third embodiment.
The manufacturing method of the secondary mirror according to the third embodiment basically includes the same steps as the manufacturing method of the secondary mirror according to the first embodiment, but the content of the microcrack removing process is the same as that of the secondary mirror according to the first embodiment. It is different from the manufacturing method.

That is, in the manufacturing method of the secondary mirror of the third embodiment, description thereof is omitted due shown in the microcracks removing step, by performing polishing on the first end face P ₁ of Fukukagamimotozai 2 It is said.

Thus, even microcracks a had occurred on the first end face P ₁ of Fukukagamimotozai 2, it is possible to remove together a portion including microcracks a. As a result, even if thermal stress is generated inside the secondary mirror, it is possible to suppress the secondary mirror from being chipped or cracked.

The manufacturing method of the secondary mirror according to the third embodiment is a point other than the content of the microcrack removing step.
Since the same process as the manufacturing method of the submirror which concerns on Embodiment 1 is included, it has an applicable effect as it is among the effects which the manufacturing method of the submirror which concerns on Embodiment 1 has.

[Embodiment 4]
In the fourth embodiment, a light source device and a projector including the secondary mirror manufactured by the secondary mirror manufacturing method according to the first embodiment will be described.

First, configurations of the light source device 100 and the projector 1000 according to the fourth embodiment will be described with reference to FIGS. 7 and 8.
FIG. 7 is a diagram illustrating an optical system of the projector 1000 according to the fourth embodiment. FIG. 8 is a diagram for explaining the light source device 110 according to the fourth embodiment.

In the following description, three directions orthogonal to each other are defined as a z-axis direction (illumination optical axis 100ax direction in FIG. 1), an x-axis direction (a direction parallel to the paper surface in FIG. 1 and perpendicular to the z-axis), and y. Let it be an axial direction (a direction perpendicular to the paper surface in FIG. 1 and perpendicular to the z-axis).

As shown in FIG. 7, the projector 1000 according to the fourth embodiment separates the illumination device 100 and the illumination light flux from the illumination device 100 into three color lights of red light, green light, and blue light and guides them to the illuminated area. The color separation light guide optical system 200 that emits light, and three liquid crystal devices 4 as electro-optic modulation devices that modulate each of the three color lights separated by the color separation light guide optical system 200 according to image information.
00R, 400G, 400B, a cross dichroic prism 500 that combines color lights modulated by these three liquid crystal devices 400R, 400G, 400B, and light combined by the cross dichroic prism 500 are projected onto a projection surface such as a screen SCR. The projector includes a projection optical system 600.

The illuminating device 100 includes a light source device 110 that emits an illuminating light beam toward the illuminated area, and a light source device 1.
A first lens array 120 having a concave lens 90 that emits the focused light from 10 as substantially parallel light, and a plurality of first small lenses 122 for dividing the illumination light beam emitted from the concave lens 90 into a plurality of partial light beams, The second lens array 130 having a plurality of second small lenses 132 corresponding to the plurality of first small lenses 122 of the first lens array 120, and approximately 1 in which the partial light beams from the second lens array 130 are aligned in the polarization direction. It has a polarization conversion element 140 that converts into a kind of linearly polarized light and emits it, and a superimposing lens 150 that superimposes each partial light beam emitted from the polarization conversion element 140 in the illuminated area.

As shown in FIGS. 7 and 8, the light source device 110 according to the fourth embodiment includes an ellipsoidal reflector 10 as a reflector, an arc tube 20 having a light emission center near the first focal point of the ellipsoidal reflector 10, and reflecting means. As a secondary mirror 60. The light source device 110 includes an illumination optical axis 10
A light beam having a central axis of 0ax is emitted.

As shown in FIG. 8, the arc tube 20 includes a tube bulb 30 containing a pair of electrodes 42 and 52 arranged along the illumination optical axis 100ax, and a pair of sealing portions extending on both sides of the tube bulb 30. 40, 50
A pair of metal foils 44 and 54 sealed in the pair of sealing portions 40 and 50, respectively, and a pair of lead wires 46 and 56 electrically connected to the pair of metal foils 44 and 54, respectively. Have. And the outer surface of the tube part 30 and the outer surface of a pair of sealing parts 40 and 50 are connected smoothly. When a voltage is applied to the lead wires 46 and 56, a potential difference is generated between the electrodes 42 and 52, a discharge is generated, and an arc image is generated. This arc image is a light emitting part.

In addition, when the conditions of the components of the arc tube 20 are exemplarily shown, the tube portion 30 and the sealing portion 40,
50 is made of, for example, quartz glass, and mercury, a rare gas, and a small amount of halogen are enclosed in the tube portion 30. The electrodes 42 and 52 are, for example, tungsten electrodes, and the metal foil 44,
For example, 54 is a molybdenum foil. The lead wires 46 and 56 are made of, for example, molybdenum or tungsten.
Further, as the arc tube 20, various arc tubes that emit light with high luminance can be employed, for example, a high pressure mercury lamp, an ultra high pressure mercury lamp, a metal halide lamp, or the like.

As shown in FIG. 8, the ellipsoidal reflector 10 includes a sealing portion (one sealing portion) 4 of the arc tube 20.
It has an opening 12 for inserting and fixing 0, and a reflecting surface 14 that reflects the light emitted from the arc tube 20 toward the second focal position. The ellipsoidal reflector 10 is fixed to the sealing portion 40 of the arc tube 20 with an inorganic adhesive C such as cement filled in the opening 12 of the ellipsoidal reflector 10.

Examples of the material of the base material constituting the reflecting surface 14 include crystallized glass and alumina (Al ₂
O ₃ ) and the like can be preferably used. For example, titanium oxide (
A visible light reflecting layer made of a dielectric multilayer film of TiO ₂ ) and silicon oxide (SiO ₂ ) is formed.

As shown in FIG. 8, the secondary mirror 60 has an opening 62 for insertion / fixation into the sealing portion (the other sealing portion) 50 of the arc tube 20 and the arc tube 20 toward the illuminated region. And a reflecting surface 64 that reflects the emitted light toward the arc tube 20. The light reflected by the secondary mirror 60 passes through the arc tube 20 and enters the ellipsoidal reflector 10. The secondary mirror 60 has an opening 6 of the secondary mirror 60.
2 is fixed to the sealing portion 50 of the arc tube 20 by an inorganic adhesive C such as cement filled in 2.

The secondary mirror 60 in the light source device 110 and the projector 1000 according to the fourth embodiment is manufactured by the secondary mirror manufacturing method according to the first embodiment.

As shown in FIG. 7, the concave lens 90 is arranged on the illuminated area side of the ellipsoidal reflector 10. The light from the ellipsoidal reflector 10 is emitted toward the first lens array 120.

The first lens array 120 has a function as a light beam splitting optical element that splits light from the concave lens 90 into a plurality of partial light beams, and a plurality of first lens arrays 120 arranged in a matrix in a plane orthogonal to the illumination optical axis 100ax. It has a configuration provided with one small lens 122. Although not illustrated, the outer shape of the first small lens 122 is similar to the outer shape of the image forming area of the liquid crystal devices 400R, 400G, and 400B.

The second lens array 130 is an optical element that collects a plurality of partial light beams divided by the first lens array 120 described above, and similarly to the first lens array 120, the illumination optical axis 100a.
It has a configuration including a plurality of second small lenses 132 arranged in a matrix in a plane orthogonal to x.

The polarization conversion element 140 is a polarization conversion element that emits the polarization direction of each partial light beam divided by the first lens array 120 as approximately one type of linearly polarized light having a uniform polarization direction.
The polarization conversion element 140 transmits one linear polarization component of the polarization component included in the illumination light beam from the light source device 110 as it is, and reflects the other linear polarization component in a direction perpendicular to the illumination optical axis 100ax. And the other linearly polarized light component reflected by the polarization separation layer is used as the illumination optical axis 10.
A reflective layer that reflects in a direction parallel to 0ax; and a retardation plate that converts the other linearly polarized light component reflected by the reflective layer into one linearly polarized light component.

The superimposing lens 150 condenses a plurality of partial light beams that have passed through the first lens array 120, the second lens array 130, and the polarization conversion element 140, and superimposes them on the vicinity of the image forming regions of the liquid crystal devices 400R, 400G, and 400B. It is an element. The superimposing lens 150 shown in FIG.
Is composed of one lens, but may be composed of a compound lens in which a plurality of lenses are combined.

As shown in FIG. 7, the color separation light guide optical system 200 includes dichroic mirrors 210 and 220.
And reflection mirrors 230, 240, 250 and relay lenses 260, 270. The color separation light guide optical system 200 separates the illumination light beam emitted from the illumination device 100 into three color lights of red light, green light, and blue light, and each color light is a liquid crystal device 400R to be illuminated.
, 400G, 400B.

The dichroic mirrors 210 and 220 are optical elements on which a wavelength selection film that reflects a light beam in a predetermined wavelength region and transmits a light beam in another wavelength region is formed on a substrate. The dichroic mirror 210 disposed in the front stage of the optical path is a mirror that reflects a red light component and transmits other color light components. The dichroic mirror 220 disposed in the latter stage of the optical path is a mirror that reflects the green light component and transmits the blue light component.

The red light component reflected by the dichroic mirror 210 is bent by the reflection mirror 230 and enters the image forming area of the liquid crystal device 400R for red light through the condenser lens 300R.

The condenser lens 300R is provided to convert each partial light beam from the superimposing lens 150 into a light beam substantially parallel to each principal ray. The condensing lenses 300G and 300B disposed in the preceding stage of the optical path of the other liquid crystal devices 400G and 400B are configured in the same manner as the condensing lens 300R.

Of the green light component and the blue light component that have passed through the dichroic mirror 210, the green light component is reflected by the dichroic mirror 220, passes through the condenser lens 300G, and enters the image forming region of the green light liquid crystal device 400G. On the other hand, the blue light component is transmitted through the dichroic mirror 220, passes through the incident side lens 260, the incident side reflection mirror 240, the relay lens 270, the emission side reflection mirror 250, and the condensing lens 300B, and is a liquid crystal for blue light. The light enters the image forming area of the apparatus 400B. The incident side lens 260, the relay lens 270, and the reflection mirrors 240 and 250 have a function of guiding the blue light component transmitted through the dichroic mirror 220 to the liquid crystal device 400B.

The reason that the incident side lens 260, the relay lens 270, and the reflection mirrors 240 and 250 are provided in the optical path of blue light is that the length of the optical path of blue light is longer than the length of the optical paths of other color lights. For this reason, a decrease in light use efficiency due to light divergence or the like is prevented. The projector 1000 according to the fourth embodiment has such a configuration because the optical path length of blue light is long, but the length of the optical path of red light is increased so that the incident side lens 260 and the relay lens 270 are configured. And the structure which uses the reflective mirrors 240 and 250 for the optical path of red light is also considered.

The liquid crystal devices 400 </ b> R, 400 </ b> G, and 400 </ b> B modulate the incident illumination light beam according to image information, and are the illumination target of the illumination device 100. Although not shown, incident side polarizing plates are arranged between the condenser lenses 300R, 300G, and 300B and the liquid crystal devices 400R, 400G, and 400B, respectively, and the liquid crystal devices 400R, 400G, and 400B, Between the cross dichroic prism 500, an exit-side polarizing plate is disposed.
The incident-side polarizing plate, the liquid crystal devices 400R, 400G, and 400B and the exit-side polarizing plate modulate light of each incident color light.
The liquid crystal devices 400R, 400G, and 400B are a pair of transparent glass substrates in which a liquid crystal that is an electro-optical material is hermetically sealed. For example, a polysilicon TFT is used as a switching element and incident according to a given image signal. Modulates the polarization direction of one type of linearly polarized light emitted from the side polarizing plate.

The cross dichroic prism 500 is an optical element that forms a color image by synthesizing an optical image modulated for each color light emitted from the emission side polarizing plate. The cross dichroic prism 500 has a substantially square shape in plan view in which four right-angle prisms are bonded together, and a dielectric multilayer film is formed on a substantially X-shaped interface in which the right-angle prisms are bonded together. The dielectric multilayer film formed at one of the substantially X-shaped interfaces reflects red light, and the dielectric multilayer film formed at the other interface reflects blue light. By these dielectric multilayer films, the red light and the blue light are bent and aligned with the traveling direction of the green light, so that the three color lights are synthesized.

The color image emitted from the cross dichroic prism 500 is output from the projection optical system 600.
Is enlarged and projected to form a large screen image on the screen SCR.

As described above, the light source device 110 according to the fourth embodiment is a light source device including the arc tube 20, the elliptical reflector 10, and the secondary mirror 60 as described above. The secondary mirror 60 is a secondary mirror manufactured by the secondary mirror manufacturing method according to the first embodiment.

For this reason, the light source device 110 according to the fourth embodiment is a high-quality light source device including the secondary mirror 60 that is excellent in surface roughness and light utilization efficiency and is inexpensive and suppressed from being chipped or broken.

In addition, the projector 1000 according to the fourth embodiment includes an illumination device 100 including the light source device 110 described above, and a liquid crystal device 400R that modulates light from the illumination device 100 according to image information.
, 400G, 400B and the projection optical system 600 that projects the light modulated by the liquid crystal devices 400R, 400G, 400B, a high-quality projector.

As mentioned above, although the manufacturing method of the reflective mirror of this invention, the light source device, and the projector were demonstrated based on said each embodiment, this invention is not limited to said each embodiment, In the range which does not deviate from the summary. For example, the following modifications are possible.

(1) In the light source device 110 and the projector 1000 according to the fourth embodiment, the secondary mirror 60 manufactured by the secondary mirror manufacturing method according to the first embodiment is used as the secondary mirror 60.
The present invention is not limited to this, and a secondary mirror manufactured by the secondary mirror manufacturing method according to Embodiment 2 may be used, or a secondary mirror manufactured by the secondary mirror manufacturing method according to Embodiment 3 may be used. A mirror may be used.

(2) In the secondary mirror manufacturing method according to Embodiment 1 described above, the case where the microcracks generated on the _first end face P1 of the secondary mirror base 2 are removed in the microcrack removing step has been exemplified. However, the present invention is not limited to this. For example, in the secondary mirror base material forming step, when not only a part of the tubular member 1 ′ (expanded part E) but also both ends are cut,
The second end surface P ₂ to microcracks Fukukagamimotozai 2 may occur. in this case,
In the microcrack removing step, microcracks generated on the _second end face P2 of the secondary mirror base material 2 may also be removed. However, after the mounting the secondary mirror in the light emitting tube, a first end face P ₁ of the Fukukagamimotozai 2 are liable to high temperatures in comparison with the second end surface P _2, the second of Fukukagamimotozai 2 End face P
Since the ₂ less likely to higher temperature than the first end face P _1, the probability of cracks are also therefrom a second end face P ₂ microcrack is present is low. Therefore, removal of micro-cracks to the second end surface P ₂ of the Fukukagamimotozai 2 may be performed as needed.

(3) As a microcrack removing step in the manufacturing method of the reflecting mirror of the present invention, Embodiment 1
Explains the case of performing an etching process on the cut surface of the sub-mirror substrate, Embodiment 2 describes the case of irradiating the cut surface of the sub-mirror substrate with laser light, and Embodiment 3 describes the sub-mirror. The case where the polishing process is performed on the cut surface of the base material has been described, and the case where each process is performed alone has been described as an example, but the present invention is not limited to this, and each process is performed together. May be. As the microcrack removing step, for example, after the grinding process is performed on the cut surface of the secondary mirror base material, the etching process may be performed on the cut surface of the secondary mirror base material, or the secondary mirror base material is cut. After polishing the surface, the cut surface of the secondary mirror base material may be irradiated with laser light.

(4) In the method for manufacturing the secondary mirror according to the first embodiment, the case where two secondary mirror base materials are formed from one tubular member has been described as an example, but the present invention is not limited to this. One sub-mirror substrate may be formed from one tubular member.

(5) In the first to third embodiments, the case where the method for manufacturing a reflecting mirror of the present invention is applied to a method for manufacturing a secondary mirror has been described, but the present invention is not limited to this, and the first embodiment described above. ~ 3
The secondary mirror manufacturing method is applied as a reflector manufacturing method, and the reflector manufactured by the reflector manufacturing method is used as the light source device 110 and the projector 10 of the fourth embodiment.
It may be used for 00.

(6) Although the example in which the light source device of the present invention is applied to a projector has been described, the present invention is not limited to this. The light source device of the present invention can also be applied to other optical devices (for example, an optical disc device).

(7) Although the light source device 110 according to Embodiment 4 uses an elliptical reflector as a reflector, the present invention is not limited to this, and a parabolic reflector can also be preferably used.

(8) In the projector 1000 according to the fourth embodiment, as a light uniformizing optical system,
Although the lens integrator optical system including the first lens array 120 and the second lens array 130 is used, the present invention is not limited to this, and a rod integrator optical system including a light guide rod can also be preferably used. .

(9) The projector 1000 according to the fourth embodiment is a transmissive projector, but the present invention is not limited to this. The present invention can also be applied to a reflection type projector. Here, “transmission type” means that an electro-optic modulation device as a light modulation means, such as a transmission type liquid crystal device, transmits light, and “reflection type”
This means that an electro-optic modulation device as a light modulation means, such as a reflective liquid crystal device, is a type that reflects light. Even when the present invention is applied to a reflective projector, the same effect as that of a transmissive projector can be obtained.

(10) In the projector 1000 according to the fourth embodiment, the three liquid crystal devices 400R
However, the present invention is not limited to this, and can be applied to a projector using one, two, or four or more liquid crystal devices. .

(11) Although the projector 1000 according to the fourth embodiment uses a liquid crystal device as the electro-optic modulation device, the present invention is not limited to this. In general, the electro-optic modulation device may be any device that modulates incident light in accordance with image information, and a micromirror light modulation device or the like may be used. As a micromirror type light modulation device, for example, DMD (
A digital micromirror device (trademark of TI) can be used.

(12) The present invention is applied to a rear projection type projector that projects from a side opposite to the side that observes the projected image, even when applied to a front projection type projector that projects from the side that observes the projected image. Is also possible.

3 is a flowchart for explaining a method for manufacturing the secondary mirror according to the first embodiment. The figure which shows each process in the manufacturing method of the sub mirror which concerns on Embodiment 1 typically. The figure which shows each process in the manufacturing method of the sub mirror which concerns on Embodiment 1 typically. The figure which shows each process in the manufacturing method of the sub mirror which concerns on Embodiment 1 typically. 9 is a flowchart shown for explaining a method of manufacturing the secondary mirror according to the second embodiment. 10 is a flowchart shown for explaining a method of manufacturing the secondary mirror according to the third embodiment. FIG. 10 is a diagram showing an optical system of a projector 1000 according to a fourth embodiment. The figure shown in order to demonstrate the light source device 110 which concerns on Embodiment 4. FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Tubular member, 1 '... Tubular member in which the expansion part was formed, 2 ... Secondary mirror base material, 10 ... Ellipsoidal reflector, 12 ... Opening part, 14 ... Reflecting surface, 20 ... Light emitting tube, 30 ... Tube part , 40, 50 ... sealing part, 42, 52 ... electrode, 44, 54 ... metal foil, 46, 56 ... lead wire, 60 ... secondary mirror, 62 ...
Opening portion, 64 ... reflecting surface, 90 ... concave lens, 100 ... illuminating device, 100ax ... illumination optical axis, 1
DESCRIPTION OF SYMBOLS 10 ... Light source device, 120 ... 1st lens array, 122 ... 1st small lens, 130 ... 2nd lens array, 132 ... 2nd small lens, 140 ... Polarization conversion element, 150 ... Superimposing lens, 200
... color separation light guide optical system, 210, 220 ... dichroic mirror, 230, 240, 250
... reflection mirror, 260 ... incident side lens, 270 ... relay lens, 300R, 300G, 3
00B ... Condensing lens, 400R, 400G, 400B ... Liquid crystal device, 500 ... Cross dichroic prism, 600 ... Projection optical system, 1000 ... Projector, a ... Microcrack, b ... U-shaped groove, C ... Inorganic adhesive , E ... expansion unit, F ... mold, the end surface of the _{P 1,} P 2 _... Fukukagamimotozai, the inner surface of the P 3 _... Fukukagamimoto material, R ... reflection layer, SCR ... screen

Claims (8)

A manufacturing method of a reflecting mirror used in a light source device including an arc tube having a light emitting unit and a reflecting mirror having a reflecting surface that reflects light from the light emitting unit in a predetermined direction,
A tubular member preparation step of preparing a tubular member made of the material of the reflecting mirror;
After the tubular member is heated and placed in the mold, the tubular member is subjected to internal pressure with an inert gas so that a part of the inner surface of the tubular member has a shape corresponding to the reflecting surface of the reflecting mirror. An inflatable portion forming step of inflating a part of the member to form an inflatable portion;
A reflecting mirror base material forming step of forming a base material of the reflecting mirror by cutting the tubular member in which the expanding portion is formed;
A microcrack removing step of removing microcracks generated on the cut surface of the base material of the reflecting mirror;
A reflective layer forming step of forming a reflective layer on a portion of the base material of the reflective mirror that serves as the reflective surface. In the manufacturing method of the reflecting mirror according to claim 1,
In the microcrack removing step, an etching process is performed on the cut surface of the base material of the reflecting mirror. In the manufacturing method of the reflecting mirror according to claim 1,
In the microcrack removing step, a laser beam is irradiated to the cut surface of the base material of the reflecting mirror. In the manufacturing method of the reflecting mirror according to claim 1,
In the microcrack removing step, a polishing process is performed on the cut surface of the base material of the reflecting mirror. In the manufacturing method of the reflecting mirror in any one of Claims 1-4,
In the expanding portion forming step, the expanding portion is formed so that a part of the inner surface shape of the tubular member becomes the shape of the reflecting surface when two reflecting mirrors face each other,
In the reflecting mirror base material forming step, two reflecting mirrors are formed. An arc tube having a tube portion having a light emitting portion and a pair of sealing portions extending on both sides of the tube portion;
A light source device including a reflector disposed on one sealing portion side of the arc tube and reflecting light from the light emitting portion toward an illuminated area side;
6. The light source device according to claim 1, wherein the reflector is a reflecting mirror manufactured by the reflecting mirror manufacturing method according to any one of claims 1 to 5. An arc tube having a tube portion having a light emitting portion and a pair of sealing portions extending on both sides of the tube portion;
A reflector disposed on one sealing portion side of the arc tube, reflecting light from the light emitting portion toward the illuminated region side, and disposed on the other sealing portion side of the arc tube; A light source device including a secondary mirror having a reflecting surface that reflects light from the light emitting unit toward the tube part,
The light source device according to claim 1, wherein the sub mirror is a reflecting mirror manufactured by the reflecting mirror manufacturing method according to claim 1. A lighting device having the light source device according to claim 6 or 7,
An electro-optic modulator that modulates light from the illumination device according to image information;
A projector comprising: a projection optical system that projects light modulated by the electro-optic modulation device.

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