JP2008234897A - Light source device and projector - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a light source device capable of efficiently using light flux from a light-emitting part by a number of reflecting mirrors and supporting each mirror without preventing light flux reflected by each mirror. <P>SOLUTION: A first reflecting mirror 2 reflects first light flux L1 of a first effective reflecting face area S1 toward a focus point FC2 ahead, a reflecting part 3c of a second reflecting mirror 3 reflects second light flux L2 of a second effective reflecting face area S2 toward a focus point FC2 ahead, and third reflecting mirror 4 reflects third light flux L3 of a third effective reflecting face area S3 toward a focus point FC1 in a body part 11, and therefore, light source light emitted from an arc tube 1 to surroundings can be efficiently used. At this time, the second reflecting mirror 3 includes a transparent part 3b for transmitting the first light flux L1, the second reflecting mirror 3 can be supported without preventing a light channel of the first reflecting mirror 2, and bright illuminating light can be emitted. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a light source device having an arc tube as a light source and a reflecting mirror for collecting light from the arc tube, and a projector using the same.

As a light source device used in a projector or the like, for example, a concave mirror such as a parabolic mirror that reflects a light beam emitted from the back to the side of the light generation unit and a light beam emitted in front of the light generation unit are reflected forward. And a concave mirror such as a parabolic mirror that can efficiently use the light emitted from the light generation unit (see Patent Document 1).
JP 2001-125197 A

  However, in the light source device as described above, it is not easy to support each concave mirror so as not to disturb the light beam reflected by each concave mirror.

  Accordingly, the present invention is a light source that can efficiently use the light flux from the light emitting unit by a number of reflecting mirrors and can support each reflecting mirror so as not to obstruct the path of the light flux reflected by each reflecting mirror. An object is to provide a device and a projector incorporating the same.

  In order to solve the above-described problems, a light source device according to the present invention includes (a) an arc tube having a main body portion that generates light source light, and (b) a reference axis extending rearward from the main body portion of the arc tube. A first reflecting mirror that reflects the first light beam emitted from the main body part in a first angle range having a small angle to the front side; (c) a transmission unit that transmits the first light beam in the first angle range; and a reference axis A second reflecting mirror having a reflecting portion for reflecting the second light beam emitted from the main body portion in the second angle range having a larger angle than the first angle range to the front side, and (d) with respect to the reference axis And a third reflecting mirror that reflects the third light beam emitted from the main body portion to the main body portion side in a third angle range that forms a large angle equal to or larger than the second angle range.

  In the light source device, the first reflecting mirror reflects the first light flux in the first angle range to the front side, the reflecting portion of the second reflecting mirror reflects the second light flux in the second angle range to the front side, and the third Since the reflecting mirror reflects the third light flux in the third angle range to the main body portion side, the light source light emitted from the arc tube to the surroundings can be used efficiently. At this time, since the second reflecting mirror has a transmission part that transmits the first light flux, the second reflecting mirror can be supported without obstructing the optical path of the first reflecting mirror, and a bright light source device can be provided. .

  According to a specific aspect or aspect of the present invention, in the light source device, the transmission part of the second reflecting mirror has an optical characteristic for correcting the lens effect of the main body part. In this case, it is possible to emit the light source light in a desired light flux state from the light source device by setting the light flux collected by the first reflecting mirror to have less aberration.

  In another aspect of the present invention, the transmission part of the second reflecting mirror has an outer shape similar to the outer shape of the main body portion. In this case, it is possible to reduce the distortion of the first light beam that is emitted from the main body portion, passes through the transmission portion, and reaches the first reflecting mirror.

  In still another aspect of the present invention, the transmission part of the second reflecting mirror has an antireflection coating on the surface. In this case, it is possible to reduce the reflection loss of the first light beam that is emitted from the main body portion, passes through the transmission portion, and reaches the first reflecting mirror.

  In yet another aspect of the present invention, the arc tube has a first sealing portion provided at the rear end of the main body portion and a second sealing portion provided at the front end of the main body portion, and the first The reflecting mirror and the second reflecting mirror are supported on the first sealing portion side, and the third reflecting mirror is supported on the second sealing portion side. In this case, the first to third reflecting mirrors can be stably supported via the arc tube without interfering with each other.

  In still another aspect of the present invention, the focal point of the first reflecting mirror and the focal point of the second reflecting mirror coincide with each other. In this case, the characteristics of the first light beam reflected by the first reflecting mirror and the second light beam reflected by the second reflecting mirror can be made uniform.

  In still another aspect of the present invention, the first reflecting mirror and the second reflecting mirror are spheroidal mirrors, and the third reflecting mirror is a first and second focal point common to the first and second reflecting mirrors. Is a spherical mirror having a single focal point coincident with one of the two. In this case, the first to third light beams can be collected at a focal point common to the first reflecting mirror and the second reflecting mirror in front of the arc tube.

  In order to solve the above problems, a projector according to the present invention includes (a) the above-described light source device, (b) a light modulation device that is illuminated by illumination light from the light source device, and (c) a light modulation device. And a projection optical system for projecting image light that has passed through.

  According to the projector, the light source device described above is provided, the light source light can be used efficiently, and a high-quality image can be projected by the bright light source device.

[First Embodiment]
(1) Light Source Unit FIG. 1 is a cross-sectional view showing a light source device according to the first embodiment of the present invention. The light source device 100 of this embodiment includes a light source unit 10 and a power supply device 80. The light source unit 10 includes a discharge light emitting type arc tube 1, an elliptical mirror type first reflecting mirror 2, an elliptical mirror type second reflecting mirror 3, a spherical mirror type third reflecting mirror 4, and a concave lens for collimation. 5. The power supply device 80 is an electric circuit for supplying an alternating current to the light source unit 10 to emit light in a desired state.

  In the light source unit 10, the arc tube 1 is a discharge light-emitting lamp such as a high-pressure mercury lamp or a metal halide lamp. The arc tube 1 is composed of a translucent quartz glass tube having a central portion swelled in a spherical shape, and a main body portion 11 that radiates light for illumination and first and second ends that extend to both ends of the main body portion 11. 2 sealing parts 13 and 14 are provided. Here, the 1st sealing part 13, the main-body part 11, and the 2nd sealing part 14 are sequentially arrange | positioned toward the front from the back of the light source unit 10 along the system optical axis OA in this order. Yes.

  In the arc tube 1, the discharge space 12 formed in the main body portion 11 has a predetermined distance between the tip of the first electrode 15 made of tungsten and the tip of the second electrode 16 made of tungsten. A gas that is a discharge medium including a rare gas, a metal halogen compound, and the like is disposed in a spaced manner. Inside each sealing portion 13, 14 extending at both ends of the main body portion 11, molybdenum metal foil 17 a electrically connected to the root portions of the first and second electrodes 15, 16, 17b is inserted and hermetically sealed. When an AC voltage is applied to the lead wires 18a and 18b connected to the metal foils 17a and 17b by the power supply device 80, arc discharge occurs between the pair of electrodes 15 and 16, and the main body portion 11 emits light with high luminance. To do. Here, as is apparent from FIG. 1, the first reflecting mirror 2 and the second reflecting mirror 3 are disposed on the first sealing portion 13 side, and the third reflecting mirror 4 is disposed on the first reflecting mirror 2 and the like. Oppositely disposed on the second sealing portion 14 side. Accordingly, the first sealing portion 13 is on the side opposite to the third reflecting mirror 4 with the main body portion 11 interposed therebetween.

  Nearly half of the main body portion 11 of the arc tube 1 on the front side of the light emission is covered by the third reflecting mirror 4. The third reflecting mirror 4 is a second sealing member that supports the sub-reflecting part 4a that returns the light beam radiated forward from the main body part 11 of the arc tube 1 to the main body part 11 and the base part of the sub-reflecting part 4a. And a support portion 4b fixed around the stopper portion 14. The support portion 4b allows the second sealing portion 14 to be inserted, and aligns the sub-reflecting portion 4a with respect to the main body portion 11 by filling the gap with the second sealing portion 14 with the inorganic adhesive MB. ing. That is, the rotational symmetry axis of the third reflecting mirror 4 and the axis of the arc tube 1 are arranged on the same system optical axis OA.

  The first reflecting mirror 2 is a mirror portion that reflects and collects the light source light emitted backward from the arc tube 1. The first reflecting mirror 2 is arranged coaxially with the arc tube 1, and the rotational symmetry axis of the first reflecting mirror 2 and the axis line of the arc tube 1 are arranged on the same system optical axis OA. Yes. The first reflecting mirror 2 includes a neck-like portion 2a through which the first sealing portion 13 of the arc tube 1 is inserted, and an elliptically curved main reflecting portion 2b extending from the neck-like portion 2a. It is an integrally molded product made of low thermal expansion glass such as (trademark). The neck-shaped portion 2 a is inserted through the first sealing portion 13 and is filled with the inorganic adhesive MB in the gap with the first sealing portion 13, thereby aligning the main reflecting portion 2 b with the main body portion 11. It can be fixed in the state. The inner glass surface of the main reflecting portion 2b is processed into an elliptical curved surface, and a reflecting surface is formed on the surface.

  The second reflecting mirror 3 is a mirror portion that reflects and collects the light source light emitted from the arc tube 1 to the side. The second reflecting mirror 3 is also arranged coaxially with the arc tube 1, and the rotational symmetry axis of the second reflecting mirror 3 and the axis of the arc tube 1 are arranged on the same system optical axis OA. Yes. The second reflecting mirror 3 includes a support part 3a through which the first sealing part 13 of the arc tube 1 is inserted, a spherical transmission part 3b extending from the support part 3a, and an elliptical curved reflection part 3c. , An integrally molded product made of low thermal expansion glass such as quartz glass or Neoceram (trademark). The support portion 3a allows the first sealing portion 13 to be inserted and fills the gap with the first sealing portion 13 with the inorganic adhesive MB so that the transmitting portion 3b and the reflecting portion 3c are attached to the main body portion 11. Can be fixed in an aligned state. The inner and outer glass surfaces of the transmission part 3b are processed into a spherical shape, and an antireflection film AR is formed on the surface. Furthermore, the inner glass surface of the reflecting portion 3c is processed into an elliptical curved surface, and a reflecting surface is formed on the surface. Here, the transmissive portion 3b has an outer shape substantially similar to the outer shape of the main body portion 11, and has an optical characteristic that generates a lens effect using a thickness distribution or the like. By making the outer shape of the transmissive portion 3b substantially similar to the outer shape of the main body portion 11, the distortion of the first light beam L1 passing through the transmissive portion 3b can be reduced. In addition, the lens effect of the main body portion 11 can be corrected by giving a distribution or the like to the thickness of the transmission portion 3b, and the first light flux L2 collected by the first reflecting mirror 2 can be corrected. The aberration can be reduced. For example, if the main body part 11 of the arc tube 1 has an effect like a convex lens, the transmission part 3b has a concave lens shape that cancels the convex lens effect of the main body part 11.

  FIG. 2 is a diagram for explaining the geometric arrangement of the first to third reflecting mirrors 2, 3, and 4. The first reflecting mirror 2 is on the first spheroid ellipsoid ES1, and the second reflecting mirror 3 is on the second spheroid ellipsoid ES2. The first focal point of the first reflecting mirror 2, the first focal point of the second reflecting mirror 3, and the single focal point of the third reflecting mirror 4 are set to coincide with the common focal point FC1. The second focal point of the first reflecting mirror 2 and the second focal point of the second reflecting mirror 3 are set to coincide with the common focal point FC2. The distance from the focal point FC1 to the first reflecting mirror 2 is F1, and the distance from the first reflecting mirror 2 to the focal point FC2 is F2. The distance from the focal point FC1 to the second reflecting mirror 3 is f1, and the distance from the second reflecting mirror 3 to the focal point FC2 is f2.

  The first reflecting mirror 2 extends in a first angle range that forms the smallest angle with respect to the reference axis OA1 that extends backward in the system optical axis OA, that is, the first effective reflecting surface range S1. Here, the first effective reflection surface range S1 is set to 30 ° ≦ S1 ≦ θ1 + 10 °, for example. The angle θ1 means a boundary angle between the first reflecting mirror 2 and the second reflecting mirror 3, and is set to 60 ° ≦ θ1 <90 °, for example. In the first angle range, that is, the first effective reflection surface range S1, the first reflecting mirror 2 reflects the light source light from the main body portion 11 of the arc tube 1, that is, the first light beam L1 emitted from the focal point FC1 and passing through the transmission part 3b. Then, the light is focused on the focal point FC2. At this time, a light beam of 30 ° or less with respect to the reference axis OA1 is blocked by the first sealing portion 13 and does not exit the arc tube 1. In addition, some of the light reflected by the first effective reflection surface range S1 is blocked by the second reflecting mirror 3, but the light blocked by the second reflecting mirror 3 is compared in the light distribution characteristics of the arc tube 1. It is light from a very weak range, and no major problem occurs even if it is not used as illumination light.

  The reflecting portion 3c of the second reflecting mirror 3 extends in a second angle range that forms the next smallest angle with respect to the reference axis OA1, that is, the second effective reflecting surface range S2. Here, the second effective reflection surface range S2 is set to θ1 ≦ S2 ≦ θ2, for example. Note that the angle θ2 means a boundary angle between the second reflecting mirror 3 and the third reflecting mirror 4, and is set to 90 ° ≦ θ2 <120 °, for example. In the second angle range, that is, the second effective reflection surface range S2, the second reflecting mirror 3 reflects the light source light from the main body portion 11 of the arc tube 1, that is, the second light beam L2 emitted from the focal point FC1, and the focal point FC2. Condensed to

  The third reflecting mirror 4 extends in a third angle range that forms the largest angle with respect to the reference axis OA1, that is, the third effective reflecting surface range S3. Here, the third effective reflection surface range S3 is set to θ2−10 ° ≦ S3 ≦ 150 °, for example. In the third angle range, that is, the third effective reflection surface range S3, the third reflecting mirror 4 reflects the light source light from the main body portion 11 of the arc tube 1, that is, the third light beam L3 emitted from the focal point FC1, and the focal point FC1. Concentrate to return to At this time, a light beam of 150 ° or more with respect to the reference axis OA1 is blocked by the second sealing portion 14 and does not exit the arc tube 1.

  In the above, the distance f1 from the focal point FC1 to the second reflecting mirror 3 is f1 ≦ F1, and it is particularly desirable that f1 × 2.5 ≦ F1. This is to prevent the first reflecting mirror 2 and the second reflecting mirror 3 from interfering with each other to increase the light shielding by the second reflecting mirror 3. Further, the distance f2 from the second reflecting mirror 3 to the focal point FC2 is f2 = F2-F1 + f1, and the first and second focal points of the first and second reflecting mirrors 2 and 3 are made to coincide with each other. The distance f1 is set to about R ± 1 mm with respect to the outer radius R (mm) of the main body portion 11 in order to reduce the light amount loss by bringing the second reflecting mirror 3 as close as possible to the main body portion 11.

  Returning to FIG. 1, the concave lens 5 is disposed coaxially facing the first reflecting mirror 2. That is, the optical axis of the concave lens 5 is disposed on the system optical axis OA that coincides with the rotational symmetry axis of the first reflecting mirror 2 and the like. The concave lens 5 is a collimator lens that collimates and emits the light source light reflected by the first and second reflecting mirrors 2 and 3, and a parallel light beam emitted from the concave lens 5 is a uniformizing optical system 20 (see FIG. 5).

  According to the light source device 100 described above, the first reflecting mirror 2 reflects the first light beam L1 emitted to the first effective reflecting surface range S1 toward the front focal point FC2, and the reflecting portion 3c of the second reflecting mirror 3 is reflected. Reflects the second light beam L2 emitted to the second effective reflection surface range S2 toward the front focal point FC2, and the third reflecting mirror 4 emits the third light beam L3 emitted to the third effective reflection surface range S3. Since the light is reflected by the focal point FC1, the light source light emitted from the arc tube 1 to the surroundings can be used efficiently. At this time, since the second reflecting mirror 3 has the transmission part 3b that transmits the first light flux L1, the second reflecting mirror 3 and the like can be supported without interfering with the optical path of the first reflecting mirror 2, and bright illumination light can be obtained. Can be provided.

  FIG. 3 is a diagram for explaining the distribution of light beams emitted from the first reflecting mirror 2 and the like. FIG. 3A shows the case of the embodiment, and FIG. 3B shows the case of a conventional comparative example without the second reflecting mirror 3. As is clear from FIG. 3A, the brightness of the intermediate band portion between the center and the outside is increased, and the light beam that has not been collected without the second reflecting mirror 3 is emitted to the front side. In FIG. 3B, the black portion at the center is a region where no light exists.

(2) Modification FIG. 4 shows a modification of the light source device 100 of FIG. In the light source unit 110 of this modification, the support portion 103a of the second reflecting mirror 103 extends long in the axial direction, and is fixed and supported by the inorganic adhesive MB on the neck portion 2a of the first reflecting mirror 2. .

  FIG. 5 shows another modification of the light source device 100 of FIG. In the light source unit 210 of this modification, the transmission part 203b of the second reflecting mirror 203 has a curvature that extends backward from the rear end of the reflection part 3c and continues from the reflection part 3c. Thus, the workability of the 2nd reflective mirror 203 can be improved by making the transmission part 203b into the curved surface continuously extended from the reflection part 3c.

(3) Projector FIG. 6 is a conceptual diagram for explaining a projector incorporating the light source device 100 shown in FIG. 1 and the like. The projector PJ in the present embodiment includes a light source device 100, a uniformizing optical system 20, a color separation light guide optical system 30, liquid crystal light valves 40a, 40b, and 40c that are light modulation devices, a cross dichroic prism 50, A projection lens 60 which is a projection optical system. Here, the light source device 100 and the homogenizing optical system 20 constitute an illumination device for forming illumination light.

  The homogenizing optical system 20 includes first and second fly-eye lenses 23a and 23b, which are a pair of fly-eye lenses constituting an integrator optical system for dividing and superimposing light, and polarization conversion that aligns the polarization direction of the light. An element 24, a superimposing lens 25 that superimposes the light that has passed through both fly-eye lenses 23a and 23b, and a mirror 26 that bends the optical path of the light are provided, thereby forming uniform illumination light. In the homogenizing optical system 20, the first and second fly-eye lenses 23a and 23b are each composed of a plurality of element lenses arranged in a matrix, and the light that has passed through the parallelizing lens 22 is divided by these element lenses. Collect and diverge individually. The polarization conversion element 24 is formed of a PBS array or the like, and has a role of aligning the polarization direction of each partial light beam divided by the first fly-eye lens 23a with one direction of linearly polarized light. The superimposing lens 25 appropriately converges the illumination light that has passed through the polarization conversion element 24 as a whole, and enables superimposing illumination on the illuminated areas of the liquid crystal light valves 40a, 40b, and 40c, which are light modulators for the respective colors at the subsequent stages.

  The color separation light guide optical system 30 includes first and second dichroic mirrors 31a and 31b, reflection mirrors 32a, 32b, and 32c, and three field lenses 33a, 33b, and 33c, and is formed by the uniformizing optical system 20. The illuminated illumination light is separated into three colors of red (R), green (G), and blue (B), and each color light is guided to the liquid crystal light valves 40a, 40b, and 40c at the subsequent stage. More specifically, first, the first dichroic mirror 31a transmits R light and reflects G light and B light among the three colors of RGB. The second dichroic mirror 31b reflects G light and transmits B light out of the two colors of GB. The R light transmitted through the first dichroic mirror 31a is incident on the field lens 33a for adjusting the incident angle via the reflecting mirror 32a. The G light reflected by the first dichroic mirror 31a and further reflected by the second dichroic mirror 31b is incident on the field lens 33b for adjusting the incident angle. Further, the B light that has passed through the second dichroic mirror 31b enters the field lens 33c for adjusting the incident angle via the relay lenses LL1 and LL2 and the reflection mirrors 32b and 32c.

  The liquid crystal light valves 40 a, 40 b, and 40 c are non-light emitting light modulation devices that modulate the spatial intensity distribution of incident illumination light, and correspond to each color light emitted from the color separation light guide optical system 30. Three liquid crystal panels 41a, 41b, 41c to be illuminated, three first polarizing filters 42a, 42c, 42c arranged on the incident side of each liquid crystal panel 41a, 41b, 41c, and each liquid crystal panel 41a, 41b, Three second polarizing filters 43a, 43b, and 43c are provided on the emission side of 41c. The R light transmitted through the first dichroic mirror 31a enters the liquid crystal light valve 40a via the field lens 33a and the like, and illuminates the liquid crystal panel 41a of the liquid crystal light valve 40a. The G light reflected by both the first and second dichroic mirrors 31a and 31b enters the liquid crystal light valve 40b via the field lens 33b and the like, and illuminates the liquid crystal panel 41b of the liquid crystal light valve 40b. The B light reflected by the first dichroic mirror 31a and transmitted through the second dichroic mirror 31b enters the liquid crystal light valve 40c through the field lens 33c and the like, and illuminates the liquid crystal panel 41c of the liquid crystal light valve 40c. Each of the liquid crystal panels 41a to 41c modulates the spatial intensity distribution of the incident illumination light, and the three colors of light incident on the respective liquid crystal panels 41a to 41c are input as electric signals to the respective liquid crystal panels 41a to 41c. It is modulated according to the drive signal or image signal. At this time, the polarization direction of the illumination light incident on the liquid crystal panels 41a to 41c is adjusted by the first polarizing filters 42a to 42c, and the light is emitted from the liquid crystal panels 41a to 41c by the second polarizing filters 43a to 43c. Modulated light having a predetermined polarization direction is extracted from the modulated light. As described above, each liquid crystal light valve 40a, 40b, 40c forms image light of each color corresponding to each.

  The cross dichroic prism 50 combines the image light of each color from the liquid crystal light valves 40a, 40b, and 40c. More specifically, the cross dichroic prism 50 has a substantially square shape in plan view in which four right angle prisms are bonded together, and a pair of dielectric multilayer films intersecting in an X shape at the interface where the right angle prisms are bonded to each other. 51a and 51b are formed. One first dielectric multilayer film 51a reflects R light, and the other second dielectric multilayer film 51b reflects B light. The cross dichroic prism 50 reflects the R light from the liquid crystal light valve 40a by the dielectric multilayer film 51a and emits it to the right in the traveling direction, and the G light from the liquid crystal light valve 40b through the dielectric multilayer films 51a and 51b. The B light from the liquid crystal light valve 40c is reflected by the dielectric multilayer film 51b and emitted to the left in the traveling direction. In this way, the R light, the G light, and the B light are combined by the cross dichroic prism 50 to form combined light that is image light based on a color image.

  The projection lens 60 enlarges the image light by the combined light formed through the cross dichroic prism 50 at a desired magnification and projects a color image on a screen (not shown).

  Since the projector PJ of this embodiment uses the light source device 100 shown in FIG. 1 and the like, the light source light can be used efficiently, and a high-quality image can be projected with bright illumination light.

[Second Embodiment]
The light source device according to the second embodiment will be described below. The light source device according to the second embodiment is a modification of the light source device according to the first embodiment, and parts that are not particularly described are the same as those of the device according to the first embodiment.

  FIG. 7A is a cross-sectional view showing the light source device according to the second embodiment. The light source unit 310 constituting the light source device of the present embodiment includes a concave lens 305 including two concentric annular zones 305a and 305b. The outer annular zone 305a is a part for collimating the first light flux L1 from the first reflecting mirror 2, and the inner annular zone 305b is parallel to the second luminous flux L2 from the second reflecting mirror 3. It is a part for making it. In this way, by dividing the concave lens 305 into the two annular portions 305a and 305b, illumination is individually performed in consideration of the difference between the condensing magnification of the first reflecting mirror 2 and the condensing magnification of the second reflecting mirror 3. Light can be formed.

  FIG. 7B illustrates a light source unit 410 obtained by modifying the light source unit 310 illustrated in FIG. In the case of the light source unit 410, the light beams L1 and L2 once condensed by the first reflecting mirror 2 and the second reflecting mirror 3 are collimated by the convex lens 405 disposed in front of the second focal point FC2. Also in this case, the convex lens 405 has two concentric annular zones 405a and 405b. The outer annular zone 405a is a part for collimating the first light beam L1 from the first reflecting mirror 2, and the inner annular zone 405b is a parallel beam of the second light flux L2 from the second reflecting mirror 3. It is a part for making it.

  In addition, this invention is not restricted to said embodiment, In the range which does not deviate from the summary, it can implement in a various aspect, For example, the following deformation | transformation is also possible.

  In the projector PJ of the above embodiment, a pair of fly-eye lenses 23a and 23b is used to divide the light from the light source device 100 into a plurality of partial light beams. The present invention can also be applied to a projector that does not use an array. Furthermore, the fly-eye lenses 23a and 23b can be replaced with rod integrators.

  Further, in the projector PJ, the polarization conversion element 24 that converts the light from the light source device 100 into a specific direction of polarization is used. However, the present invention is also applicable to a projector that does not use such a polarization conversion element 24. is there.

  In the above embodiment, an example in which the present invention is applied to a transmissive projector has been described. However, the present invention can also be applied to a reflective projector. Here, “transmission type” means that a liquid crystal light valve including a liquid crystal panel transmits light, and “reflection type” means that the liquid crystal light valve reflects light. It means that there is. The light modulation device is not limited to a liquid crystal panel or the like, and may be a light modulation device using a micromirror, for example.

  The projector includes a front projector that projects an image from the direction of observing the projection surface and a rear projector that projects an image from the side opposite to the direction of observing the projection surface. The projector configuration shown in FIG. Is applicable to both.

  Further, in the above embodiment, only the example of the projector PJ using the three liquid crystal panels 41a to 41c is given, but the present invention is a projector using only one liquid crystal panel, a projector using two liquid crystal panels, Or it is applicable also to the projector using four or more liquid crystal panels.

It is a plane sectional view explaining the light source device of a 1st embodiment. It is sectional drawing explaining the function of the light source device of FIG. It is a figure explaining distribution of the light beam inject | emitted from a 1st reflective mirror. It is sectional drawing explaining the modification of the light source device of FIG. It is sectional drawing explaining another modification of the light source device of FIG. It is a conceptual diagram explaining a projector provided with the light source device of FIG. (A), (B) is sectional drawing explaining the light source device of 2nd and 3rd embodiment.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Arc tube, 2 ... 1st reflective mirror, 2b ... Main reflection part, 3 ... 2nd reflection mirror, 3b ... Transmission part, 3c ... Reflection part, 4 ... 3rd reflection mirror, 4a ... Sub-reflection part, 4b ... Supporting part, 5 ... concave lens, 10 ... light source unit, 11 ... main body part, 12 ... discharge space, 13 ... first sealing part, 14 ... second sealing part, 15, 16 ... electrode, 20 ... homogenizing optical system 22 ... Parallelizing lens, 23a, 23b ... Fly eye lens, 24 ... Polarization conversion element, 25 ... Superimposing lens, 30 ... Color separation light guide optical system, 31a, 31b ... Dichroic mirror, 40a, 40b, 40c ... Liquid crystal light Valve, 41a, 41b, 41c ... Liquid crystal panel, 50 ... Cross dichroic prism, 60 ... Projection lens, 80 ... Power supply device, 100 ... Light source device, AR ... Antireflection film, ES1 ... First Ellipsoidal surface, ES2 ... second spheroidal surface, FC1, FC2 ... focus, L1 ... first light beam, L2 ... second light beam, L3 ... third light beam, OA ... system optical axis, OA1 ... reference axis, PJ ... projector, S1 ... 1st effective reflection surface range, S2 ... 2nd effective reflection surface range, S3 ... 3rd effective reflection surface range

Claims (8)

An arc tube having a body portion for generating light source light;
A first reflecting mirror that reflects the first light beam emitted from the main body portion to the front side in a first angle range that forms the smallest angle with respect to a reference axis extending backward from the main body portion of the arc tube;
A transmitting portion that transmits the first light flux in the first angle range; and a second light flux emitted from the main body portion in a second angle range that forms a larger angle than the first angle range with respect to the reference axis. A second reflecting mirror having a reflecting portion reflecting to the side;
A third reflecting mirror that reflects the third light beam emitted from the main body part to the main body part side in a third angle range that forms a larger angle than the second angle range with respect to the reference axis;
A light source device comprising:   The light source device according to claim 1, wherein the transmission part of the second reflecting mirror has an optical characteristic for correcting a lens effect of the main body part.   3. The light source device according to claim 1, wherein the transmission portion of the second reflecting mirror has an outer shape similar to the outer shape of the main body portion.   The light source device according to any one of claims 1 to 3, wherein the transmissive portion of the second reflecting mirror has an antireflection coating on a surface thereof. The arc tube has a first sealing portion provided at a rear end of the main body portion, and a second sealing portion provided at a front end of the main body portion,
5. The first reflecting mirror and the second reflecting mirror are supported on the first sealing portion side, and the third reflecting mirror is supported on the second sealing portion side. The light source device according to any one of the above.   The light source device according to claim 1, wherein a focal point of the first reflecting mirror and a focal point of the second reflecting mirror coincide with each other. The first reflecting mirror and the second reflecting mirror are spheroidal mirrors,
The light source device according to claim 6, wherein the third reflecting mirror is a spherical mirror having a single focal point that coincides with one of the first and second focal points common to the first and second reflecting mirrors. The light source device according to any one of claims 1 to 7,
A light modulation device illuminated by illumination light from the light source device;
A projector comprising: a projection optical system that projects image light that has passed through the light modulation device.

Images