JP2007333942A - Optical element holding mechanism, light source device and projection type display apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reduce a cost of an optical element holding mechanism which holds an optical element such as a lens by simplifying the mechanism, to obtain a compact, highly efficient light source device by applying the optical element holding mechanism, and to provide the projection type display apparatus that is compact and has high luminance by adopting the light source device. <P>SOLUTION: The lens 20 is held by a lens holder 1 (optical element holding mechanism) having an annular holding section and two or more claw-like holding sections, and is disposed in the predetermined position of the light source device 30 via two mounting arms. Among light rays emitted from a light emission tube 31, light rays that do not pass through the lens 20 are reflected by an elliptic reflector 33 without being intercepted by the lens holder, and condense in a desired area Sp. The light rays entering the lens 20 are emitted diverging from its central part to the maximum diameter and most of the light rays condense in the desired area Sp. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an optical element holding mechanism that holds an optical element such as a lens, a light source device that arranges a lens held by the optical element holding mechanism in the device, and a projection display device that includes the light source device.

As a conventional optical element holding mechanism, for example, there is a lens barrel system shown in FIG. The lens holding mechanism by this lens barrel method includes a cylindrical lens barrel casing 51 having an annular lens receiving portion at the front portion, an inner cylinder body 52 having an outer diameter slightly smaller than the inner diameter of the lens barrel casing 51, It consists of a lens barrel lid 53, and the lens 20 is inserted from the rear opening of the lens barrel casing 51 and pushed into the lens 20 by the inner cylinder 52. Since the receiving surface portion 51a of the front opening portion of the lens barrel housing 51 is an opening smaller than the lens diameter, the lens 2 stops at the position of the receiving surface portion 51a, and in this state, a female screw 53a is formed on the inner peripheral surface. The lens barrel lid 53 is fixedly engaged with a male screw 51 b formed on the rear outer peripheral surface of the lens barrel casing 51 to fix the lens 20.
The above-described lens barrel case is used for a product such as a projection lens having a plurality of lenses, and a strong metal is mainly used for the lens barrel case.

  Further, as shown in FIG. 15, the lens 20 is brought into contact with the receiving surface portion 61 a of the front opening portion of the lens barrel 61 so as to fix the lens in the lens barrel without using the inner cylinder body, and is arranged on the inner surface of the rear opening portion. 16 is inserted into the ring retaining groove 61b of the lens barrel 61 in a state where the ring diameter is reduced by pressing the spring-type ring 62 as shown in FIG. Thus, a method of fixing the lens 20 is often used.

In addition, as a mechanism for holding a lens in a lamp device such as a projector, for example, as in Patent Document 1, a cylindrical extending portion is provided on an elliptical reflector that reflects light from a light source forward, and a lens mounting member is provided at the tip thereof. There are some which hold the lens via
Further, Patent Document 2 is a light source device proposed by the present applicant, and in a light source device of an optical axis vertical arrangement type, a lens holding member provided in an elliptical reflector located in front of the light source is used in the light source device. A lens is disposed on the surface.

If strength such as heat resistance and vibration resistance is not required, the lens barrel case may be divided into two parts, and the lens may be arranged by providing a lens holding groove inside the lens barrel case. Resin is mainly used as the material of the lens barrel housing at that time. In addition, if a relatively soft resin is used for the lens barrel, such as a frame of eyeglasses, the lens can be held without dividing the lens barrel.
JP 2004-335395 A JP 2005-234471 A

However, a lens barrel-type optical element holding mechanism that inserts a lens into a lens barrel housing and presses and holds the lens with an inner cylinder or a spring-type ring has an annular member having a diameter smaller than the lens diameter and holds the periphery of the lens. Due to the pressing structure, the effective diameter of the lens is reduced, and a light capture loss occurs. Increasing the lens diameter and increasing the diameter of the lens barrel housing improves the light utilization efficiency, but this increases the size of the lens barrel and lens, resulting in increased costs and a smaller device. There are few cases that can be adopted when it is necessary to make it easier, because the assembly becomes difficult.
Further, the lens holding mechanism as in Patent Document 1 also has a long axial size, and thus cannot be employed in a light source device of an optical axis vertical arrangement type for the purpose of miniaturization.
In addition, when a lens barrel-type lens holding mechanism is employed in a light source device that is vertically disposed on the optical axis, a lens barrel is present in the direction of the principal axis of the light beam, obstructing the light beam reflected by the second reflector, and utilizing light Efficiency will decrease.
Although the lens holding mechanism in Patent Document 2 suggests that the lens is held without using a lens barrel type in a light source device of an optical axis vertical arrangement type, the invention disclosed in this document is specific. It does not propose a lens holding mechanism.
Some light source devices such as projectors do not have a lens in the light source device, but if there is no lens, as will be described later, a part of the light from the light source diverges without reaching the desired condensing point. As a result, the light utilization efficiency decreases.
In view of the present situation as described above, the present invention has an optical element holding mechanism that has a simple structure and that allows easy assembly of optical elements and that does not cause a decrease in light utilization efficiency. It is an object of the present invention to provide a light source device with improved light utilization efficiency and a projection display device including the light source device.

The present invention includes the following technical means in order to solve the above problems.
The first technical means is an optical element holding mechanism for holding an optical element, and the optical element holding part is formed at the tip part and an annular holding part that supports the light emitting surface side peripheral part of the optical element. And at least two claw-shaped holding portions that press the incident surface side peripheral portion of the optical element with the claw portions, and the claw-shaped holding portions are integrated with the annular holding portion at a predetermined interval from each other. It is characterized by being provided.

According to a second technical means, in the first technical means, the claw portion is formed by being bent.
The third technical means is characterized in that, in the second technical means, a portion to be bent of the claw portion is narrow.
According to a fourth technical means, in the first technical means, the claw shape holding portion presses the peripheral edge portion of the optical element in a state where the vicinity of the base of the claw shape holding portion is bent.
According to a fifth technical means, in the fourth technical means, the claw-shaped holding part is characterized in that a portion to be bent in the vicinity of the root is narrow.

According to a sixth technical means, in the first technical means, the claw portion is a hook-like claw.
According to a seventh technical means, in the sixth technical means, the hook-like claw is formed by bending.
According to an eighth technical means, in the sixth or seventh technical means, the claw-shaped holding portion on which the hook-shaped claw is formed has elasticity, and the optical element is pushed in against the elastic force to push the optical element. It is characterized by the fact that it can be assembled.
According to a ninth technical means, in any one of the first to eighth technical means, the optical element holding portion holds an optical element having a convex shape on a light incident side.

According to a tenth technical means, in any one of the first to ninth technical means, at least two mounting arms are integrally provided on the annular holding portion.
An eleventh technical means is the tenth technical means characterized in that the mounting arm has a fixing portion at the tip.
A twelfth technical means is a light source device having an arc tube and a reflector that reflects light of the arc tube forward, and is held in front of the arc tube by an optical element holding mechanism of the eleventh technical means. It is characterized in that an additional lens is provided.

A thirteenth technical means is characterized in that, in the twelfth technical means, the optical element holding mechanism holding the lens is attached to the reflector by a fixing portion of the attachment arm.
A fourteenth technical means is the optical system according to the thirteenth technical means, wherein the reflector is an elliptical reflector disposed in front of the arc tube.
According to a fifteenth technical means, in the fourteenth technical means, the lens held by the optical element holding mechanism is a condensing lens, and among the light rays emitted from the arc tube, on the narrow mouth side of the elliptical reflector. It is characterized in that it is arranged in a circumferential space formed from the point where the reflected light beam and the light beam irradiated to the wide-mouth side of the elliptical reflector intersect.
The sixteenth technical means is a projection display device comprising the light source device of the fifteenth technical means.

According to the present invention, it is possible to provide an optical element holding mechanism having the following effects.
-Light loss on the light incident side is minimized, and there is no light loss on the light exit side, so that the light utilization efficiency can be improved.
-Since the components are simple and have a simple shape, the cost can be reduced in terms of material costs.
In addition, since the constituent member is a single member, it can be easily assembled to the base material, and the cost can be reduced in terms of the time of the process.
・ Furthermore, since it has a single component and can be easily assembled to a substrate, it can be used for various optical products and has excellent versatility.
-Moreover, according to this invention, it becomes possible to provide a light source device with little light loss by using said optical element holding | maintenance mechanism.
In addition, in the light source device of the optical axis vertical arrangement type, when the condensing lens is arranged using the optical element holding mechanism, the dimension in the optical axis direction can be significantly shortened.
In addition, according to the present invention, it is possible to provide a projection display device that is small and has high brightness by adopting the above light source device as a light source.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
In the following description of the embodiments, the optical element holding mechanism according to the present invention is expressed as a “lens holder” for convenience.
FIG. 1 schematically shows a configuration in which a lens held using a lens holder according to the present invention is arranged in a light source device used in a projector or the like. The light source device 30 is an arc discharge light source 31 having an optical axis pair of main electrodes, located behind the arc tube 31, a first reflector 32 formed of a spherical surface, and an ellipse forward from the arc tube 31. It has the 2nd reflector 33 which consists of a surface.

  As will be described in detail with reference to FIG. 3, the lens holder 1 according to the embodiment of the present invention includes three claw-shaped holding portions 1a located on the light incident side and an annular holding portion 1b located on the light emitting side. A lens holding portion, two mounting arm portions 1c and a fixing portion 1d are provided. The lens holder 1 is attached to the second reflector 33 by a fixing portion 1d provided at the tip of the mounting arm portion 1c, whereby the lens 20 held by the three claw-shaped holding portions 1a and the annular holding portion 1b. Are arranged in a circumferential space formed by a point where a light beam reflected on the narrow-mouth side of the elliptical reflector and a light beam irradiated on the wide-mouthed side of the elliptical reflector among the light beams emitted from the arc tube 31 intersect.

  In FIG. 1, the optical path when the lens is not arranged in the light source device will be described. The optical path of the outgoing light from the arc tube 31 is roughly divided by the optical path (path) passing from the light source O to the second reflector 33. Oc-Sp) and two optical paths that do not pass through the second reflector 33 (path Od). In the optical path A, the light beam of the arc tube 31 is reflected by the first reflector 32 and the second reflector 33 and is condensed in a desired region Sp. In the optical path B (path O-d), since there is no lens 20, neither reflector passes through, and the light beam of the arc tube 31 spreads radially and does not converge on the desired region Sp.

Therefore, in order to condense the light beam in the optical path B in the desired region Sp, the lens 20 takes the principal point in the optical axis, and the opening portion of the second reflector 33 among the light beams emitted forward from the arc tube 31. It arrange | positions so that the peripheral part of the lens 20 may be located in the point where the light ray irradiated to the vicinity and the light ray which reflects in the innermost part of the 2nd reflector 33 and reaches | attains a desired area | region intersect. At this time, the light beam in the optical path B is a path Oa-Sp when a point on the entrance surface of the lens 20 is a, and a path Oba-Sp when a point where the first reflector 32 is ab. It becomes.
Since the lens holder according to the embodiment of the present invention has a claw-shaped member that supports the lens surface on the light incident side, the light beam from the arc tube 31 is centered on the lens 20 as shown in FIG. The light is irradiated from the portion to the maximum diameter, and most of the light is focused on the desired region Sp.
When the member that supports the lens surface on the light incident side is not a claw shape but an annular shape, the light beam applied to the lens 20 reaches the position a, and the utilization efficiency is lowered.

In the conventional lens holder, a part of the light beam from the light source O of the arc tube 31 that is incident on the lens holding part of the lens holder is lost, but the lens holding shape on the incident side in this embodiment has three claw shapes. Since it is the holding part 1a, the amount of light incident loss is small and less than 0.3%. When the holding portion has an annular shape with a width of 1.0 mm, the light loss here is about 2%.
Furthermore, in the case of the present invention, the incident side shape of the lens 20 is designed to have a curvature that does not enter the exit side annular holding portion 1b of the lens holder 1, thereby reducing the light incident loss on the annular holding portion 1b side to zero. And the light utilization efficiency is greatly improved.

  Next, the lens holder according to the first embodiment of the present invention will be described in detail including the assembling method. 3 is a front view, a top view and a side view of the lens holder, FIG. 4 is a perspective view of the lens holding portion, and the lens holding portion of the lens holder 1 is held in an annular shape by three claw-shaped holding portions 1a. The unit 1b is integrally provided with a predetermined interval. Further, the annular holding portion 1b is integrally provided with a mounting arm 1c having a fixing portion 1d having a screw hole formed at the tip thereof on the left and right sides. The lens holder 1 in the light source device 30 shown in FIG. 1 is attached using this attachment arm 1c.

  FIG. 5 shows a state in which the lens 20 is held by the lens holder 1, and the lens holding portion of the lens holder 1 is the claw-shaped holding portion 1a on the light source side, that is, the incident side, as described above. The lens 20 is held in a chuck manner by the three claws. The direction opposite to the light incident side, that is, the light emitting side is the annular holding portion 1b, and when the lens 20 is chucked by the claw-shaped holding portion 1a, the annular holding portion 1b is pressurized. The position accuracy is maintained by being fixed.

Next, a specific example of the method of assembling the lens in the lens holder according to the first embodiment of the present invention will be described with reference to FIG. As shown in FIG. 6A, the lens holder 1 in this example is one in which the claw portion (tip portion) of the claw shape holding portion 1a is not bent before the lens is assembled.
FIG. 6B shows a lens assembly jig, in which 2a is a lens holder seat surface, 2b is a lens holder holding wall, and 2c is a claw-shaped holding portion 1a when the lens holder is set on the jig. Reference numerals 2d denote escape grooves for releasing the mounting arm portion 1c. Reference numeral 2e denotes a claw bending mechanism that is operated by a hydraulic mechanism or the like, and schematically shows the claw bending mechanism.

  FIG. 6C shows a state in which the lens holder 1 shown in FIG. 6A is set in the lens assembly jig 2, and the claw-shaped holding portion 1a of the lens holder 1 is placed on the lens holder seat surface 2a. Place it so that. At this time, the lens holder holding wall 2b is provided with the above-described relief grooves 2c and 2d, so that the lens holder holding wall 2b suppresses the outer periphery of the annular holding portion 1b of the lens holder 1, and the lens holder 1 Fixed. In this state, the lens 20 is placed on the annular holding portion 1b. Next, the claw bending mechanism 2e is operated, the claw shape holding portion 1a is bent to a predetermined angle, and the lens 20 is fixed. FIG. 6D shows a state where the claw portion is bent in the lens assembly jig 2 and the lens 20 is assembled.

7 and 8 show a lens holder and its assembling method according to the second embodiment of the present invention. In this case, as shown in FIG. 7, the lens holder 3 has a claw-shaped holding portion 3a. The narrow portion 3a ₁ is formed at the root portion, and before the lens is assembled, the claw-shaped holding portion 3a that is spread outward is used to the extent that the lens can pass.
First, the lens holder 3 is placed on the lens assembly jig 4 as shown in FIG. Next, the lens 20 is inserted inside the claw-shaped holding portion 3a of the lens holder 3 and placed on the annular holding member 3b of the lens holder 3 as shown in FIG. In this state, the claw bending mechanism 4a of the lens assembly jig 4 is rotated about the rotation shaft 4b, and the claw shape holding portion 3a of the lens holder 3 is bent. FIG. 8C shows a state in which the lens 20 is fixed by bending the lens holder at the narrow portion 3a ₁ described above.

FIGS. 9 and 10 show the lens holder and its assembling method according to the third embodiment of the present invention. In this case, the lens holder 5 has a claw-shaped holding portion before assembling the lens. A linear shape is used, in which the narrow portion 5a ₁ is formed at the portion where the nail shape is to be formed. In the case of the present embodiment, the inner diameter connecting each holding portion is approximately the same as the outer shape of the lens 2.
First, as shown in FIG. 9, the lens 20 is inserted into the linear claw-shaped holding portion 5a of the lens holder 5 and placed on the annular holding member 5b. In this state, when the claw folding mechanism 6a of the lens assembly jig 6 is slid in the horizontal direction by a hydraulic mechanism or the like as shown in FIG. bent at a point width portion 5a _1.
FIG. 10B shows a state where the nail shape holding portion 5a is bent and the lens 20 is fixed.

FIG. 11 shows a lens holder and its assembling method according to the fourth embodiment of the present invention. In this example, as shown in the drawing, the tip of the claw-shaped holding portion 7a of the lens holder 7 has a sharp hook shape. and it has a claw 7a _1.
In this case, the lens holder 7 and the lens 20 are assembled by two jigs.
First, the lens holder 7 is placed and fixed on the lens assembly jig 2 described with reference to FIG. 6 (however, the claw-shaped bending mechanism is not required) so that the claw-shaped holding portion 7a faces upward.

Next, the lens 20 is placed on the annular holding portion 7b of the lens holder 7 and fixed with a lens holding jig (not shown). The fixing method is a method having a relatively high holding strength such as a robot hand method or a suction method. That is, the lens holding jig and the lens 20 are simultaneously slid, and the lens 20 is inserted so as to push and spread the portion of the hook-shaped claw 7a ₁ of the claw-shaped holding portion 7a. When the lens 20 is inserted to a predetermined position, the hook-shaped claw 7a ₁ of the claw-shaped holding portion 7a returns to the inner side from the peripheral portion (maximum diameter) of the lens 20, and the lens 20 is fixed. In this case, it is preferable that the lens holder 7 is a spring metal.

  FIG. 12 shows a lens holder and its assembling method according to the fifth embodiment of the present invention. In this example, the tip claw portion of the claw-shaped holding portion 8a of the lens holder 8 is bent 90 degrees or more as shown in the figure to form a hook-shaped claw, which is formed in a folding manner in the manufacturing process. In the lens holder 3 of FIG. 8 described above, the nail shape holding portion 3a must be widened before the lens 20 is fitted. In the case of this embodiment, the lens 20 is fitted as in the example shown in FIG. Only assembly is possible.

FIG. 13 is a schematic diagram showing a schematic configuration of a projection display apparatus including a light source device using the optical element holding mechanism of the present invention.
The video display device according to the embodiment of the present invention includes a light source device 30 in which the lens 20 is disposed by the lens holder according to the present invention, a color wheel 41, a rod integrator 42, a condenser lens group 43, a mirror 44, a light valve 45, and And an optical system 40 having a projection lens 46. The image light beam from the projection display device is projected onto the screen S to be a video.

The light beam emitted from the arc tube 31 is reflected by the reflectors 32 and 33 and enters and exits the lens 20 to be condensed on the incident surface (Sp: condensing point) of the rod integrator 42.
The color wheel 41 is formed in a disk shape by arranging R (red) filters, G (green) filters, and B (blue) filters in the circumferential direction.

The rod integrator 42 shapes the light beam emitted from the light source device 30 into a planar shape similar to the planar shape of the light valve 45 (in this case, a rectangle or a square) and makes the illuminance of the desired surface uniform.
As the color wheel 41 rotates, the light rays emitted from the light source device pass through the filters R, G, and B, and the transmitted light corresponding to the colors of the filters R, G, and B sequentially passes to the rod integrator 42. Incident.

  The light valve 45 is a projection medium that forms a projection image, and will be described here using a DMD (Digital Micro-mirror Device). In the case of DMD, a mirror for each minute section controls the reflection direction of light according to a desired projection image, and an R color image is input when an R color light is incident, a G color image is incident when a G color light is incident, and a B color light is incident. A B color image is displayed and a projection light image of each color light is formed.

That is, the light intensity of the desired surface of the light beam group is made uniform by the rod integrator 42, advances through the optical system of the condenser lens group 43 and the mirror 44, enters the light valve 45, and forms a projection light image. It has become.
Then, the projection light image formed by the light valve 45 passes through the projection lens 46 and irradiates the screen 47 to project an image.

Note that the present invention is not limited to the above-described embodiments, and the following modifications are possible.
The light source device according to each of the embodiments described above has been described as a light source device used for a projection video display device, but is not limited thereto, and can be used for other exposure devices, general illumination, and the like.
Further, the projection type image display device applies the light source device according to each embodiment of the present invention even if the light path is different from that shown in FIG. 13 or the light bulb uses a liquid crystal. be able to.
In the above embodiment, the arc tube is shown as the light source. However, the present invention is not limited to this, and other known light sources can be adopted as the light source.
Furthermore, the optical element holding mechanism according to the present invention is not limited to the lens holder in the light source device as described above, but can be used for various devices including an optical system such as a camera, a digital camera, and a camera-equipped mobile phone.

It is explanatory drawing which showed typically the basic composition of the light source device to which the optical element holding mechanism of this invention was applied. It is explanatory drawing explaining the effect at the time of using the lens holder concerning embodiment of this invention. It is the front view, top view, and side view of a lens holder which concern on the 1st Embodiment of this invention, and is the figure shown excluding the lens. It is a perspective view of the lens holder concerning the 1st Embodiment of this invention. It is explanatory drawing holding a lens in the lens holder concerning the 1st Embodiment of this invention. It is explanatory drawing when a lens is assembled | attached to the lens holder concerning the 1st Embodiment of this invention using a lens assembly jig. It is a figure which shows a shape of the lens holder concerning the 2nd Embodiment of this invention. It is explanatory drawing at the time of attaching a lens using the lens assembly jig to the lens holder concerning the 2nd Embodiment of this invention. It is explanatory drawing about the lens assembly of the lens holder concerning the 3rd Embodiment of this invention. It is explanatory drawing in the case of assembling the lens holder concerning the 3rd Embodiment of this invention with a lens assembly jig. It is explanatory drawing about the lens assembly of the lens holder concerning the 4th Embodiment of this invention. It is explanatory drawing about the lens assembly of the lens holder concerning the 5th Embodiment of this invention. It is explanatory drawing about the basic composition of the projection type display apparatus containing the light source device incorporating the lens hold | maintained by the lens holder which concerns on embodiment in this invention. It is explanatory drawing about the conventional lens-barrel type lens holder. It is explanatory drawing of the conventional lens-barrel type lens holder using a spring type ring. It is explanatory drawing of a spring type ring.

Explanation of symbols

1, 3, 5, 7, 8 ... lens holder (optical element holding mechanism), 1a, 3a, 5a, 7a, 8a ... claw-shaped holding portion, 1b, 3b, 5b, 7b, 8b ... annular holding portion, 1c ... Mounting arm part, 1d ... Fixing part, 2,4,6 ... Lens assembly jig, 2a ... Lens holder seat surface, 2b ... Lens holder holding wall, 2c, 2d ... Escape groove, 2e, 4a, 6a ... Nail Bending mechanism, 20 ... lens, 30 ... light source device, 31 ... arc tube, 32 ... first reflector, 33 ... second reflector, 40 ... optical system, 41 ... color wheel, 42 ... rod integrator, 43 ... condenser lens group, 44 ... Mirror, 45 ... Light valve (DMD), 46 ... Projection lens, 100 ... Projection display, S ... Screen.

Claims (16)

  An optical element holding mechanism that holds an optical element, and the optical element holding part is formed by an annular holding part that supports a peripheral part on the light emitting surface side of the optical element, and a claw part formed at a tip part of the optical element. At least two claw-shaped holding portions that press the surface side peripheral edge portion, and the claw-shaped holding portions are integrally fixed to the annular holding portion at a predetermined interval. An optical element holding mechanism.   The optical element holding mechanism according to claim 1, wherein the claw portion is formed by bending.   The optical element holding mechanism according to claim 2, wherein a portion to be bent of the claw portion is narrow.   2. The optical element holding mechanism according to claim 1, wherein the claw shape pressing portion presses a peripheral edge portion of the optical element in a state in which the vicinity of the base of the claw shape holding portion is bent.   5. The optical element holding mechanism according to claim 4, wherein the claw-shaped holding portion has a narrow width at a bent portion near the base.   The optical element holding mechanism according to claim 1, wherein the claw portion is a hook-shaped claw.   The optical element holding mechanism according to claim 6, wherein the hook-shaped claw is formed by bending.   The claw-shaped holding portion on which the hook-shaped claw is formed has elasticity, and the optical element can be assembled by pushing the optical element against the elastic force. 8. The optical element holding mechanism according to 7.   The optical element holding mechanism according to claim 1, wherein the optical element holding unit holds an optical element having a convex shape on a light incident side.   10. The optical element holding mechanism according to claim 1, wherein at least two mounting arms are integrally provided on the annular holding portion.   The optical element holding mechanism according to claim 10, wherein the mounting arm has a fixing portion at a tip.   A light source device having an arc tube and a reflector that reflects light from the arc tube forward, and a lens held by the optical element holding mechanism according to claim 11 is disposed in front of the arc tube. A light source device characterized by that.   The light source device according to claim 12, wherein the optical element holding mechanism that holds the lens is attached to the reflector by a fixing portion of the attachment arm.   The light source device according to claim 13, wherein the reflector is an elliptical reflector disposed in front of the arc tube.   The lens held by the optical element holding mechanism is a condensing lens, and of the light emitted from the arc tube, the light reflected on the narrow-mouthed side of the elliptical reflector and the light irradiated on the wide-mouthed side of the elliptical reflector The light source device according to claim 14, wherein the light source device is disposed in a circumferential space formed by points intersecting each other.   A projection display device comprising the light source device according to claim 15.

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