JP5510591B2 - REFLECTOR, LIGHT SOURCE DEVICE, AND PROJECTOR - Google Patents

Description

  The present invention relates to a reflector, a light source device, and a projector, and more particularly to a reflector technology used for a light source device of a projector.

  In order to improve portability and ease of installation, the projector is required to be thin. 2. Description of the Related Art Conventionally, a reflector that reflects light emitted from a light emitting unit is used in a lamp used as a light source of a projector, for example, a discharge lamp such as an ultra-high pressure mercury lamp. In order to allow light to efficiently travel to the surface to be irradiated, many reflectors employ a shape that forms a rotating curved surface, such as a rotating ellipsoid or a rotating paraboloid. The reflector needs to have a sufficient size in order to efficiently propagate light to the irradiated surface. For this reason, in the illumination optical system of the projector, in particular, the reflector often becomes an obstacle to making the projector thinner. A light source device including a reflector is required to be able to efficiently advance light to an irradiated surface and to be thin. Conventionally, for example, Patent Document 1 proposes a technique for enabling a light source device including a reflector to be thinned. The technique proposed in Patent Document 1 is to reduce the thickness of the light source device by using a cylindrical reflector. By providing a plurality of reflecting surfaces formed along the circumferential direction of the cylindrical body on the inner surface of the reflector, light is condensed at a position on the central axis.

JP 2007-93989 A

  The reflecting surface for condensing light at a position on the central axis is provided on the surface of a corrugated structure, for example, a Fresnel-shaped structure provided in a Fresnel lens. The Fresnel-shaped structure has a backward surface provided between the reflecting surfaces. The backward surface is formed along the circumferential direction of the cylindrical body, similarly to the reflective surface. A part of the light emitted from the light emitting unit is incident on the rear surface directly from the light emitting unit or after being reflected by the reflecting surface. The light incident on the backward surface travels in a direction different from the direction of the irradiated surface. For this reason, according to the conventional technique, there arises a problem that it is difficult to efficiently advance light to the irradiated surface. The present invention has been made in view of the above-described problems, and an object of the present invention is to provide a reflector that can be made thin and that allows light to efficiently travel to an irradiated surface, a light source device that uses the reflector, and a projector. To do.

In order to solve the above-described problems and achieve the object, a reflector according to the present invention is used in combination with a light emitting unit that emits light, and is a reflector provided around a central axis on which the light emitting unit is disposed. there are, without substantially the same shape as the spheroid obtained by rotating an ellipse about said central axis, and a curved reflective portion for reflecting light from the light emitting portion, the center with respect to the rotational ellipsoid A plane deflection unit provided on the axis side, the plane deflection unit comprising a plurality of structures having a reflecting surface for reflecting light from the light emitting unit to the front side, and the light emitting unit of the elliptical shape In the case of disposing the first focal point or in the vicinity of the first focal point, the plurality of structures are positions corresponding to the second focal point of the ellipse or positions corresponding to the second focal point in the planar deflection unit. Concentric circle centered around Characterized in that it is arranged.

“Front side” is the side where the irradiated surface is seen from the light emitting part, and “deflect (reflect) light toward the front side” means that light is deflected (reflected) toward the side where the irradiated surface is located. Suppose that The rotating curved surface centered on the central axis is a curved surface obtained by rotating a predetermined curve around the central axis. The reflector can be made thinner by providing a plane deflector as compared with a case where only the rotating curved surface is provided. By making the light incident on the plane deflection unit travel forward without returning to the light emitting unit, loss due to light returning to the light emitting unit, for example, loss due to absorption or scattering by the lamp, is reduced, and light is efficiently applied to the irradiated surface. To advance. By providing a plurality of structures instead of a simple planar reflecting surface, the planar polarizing section can be configured to efficiently advance light incident from the light emitting section to the front side. The curved reflecting portion has substantially the same shape as the rotating curved surface, so that light can efficiently travel to the irradiated surface. Thereby, it is possible to obtain a reflector that can be made thin and that allows light to efficiently travel to the irradiated surface.

  Moreover, as a preferable aspect of the present invention, the planar deflection unit includes a first planar deflection unit and a second planar deflection unit provided at a position facing the first planar deflection unit via the central axis. Is desirable. By making the first plane deflection unit and the second plane deflection unit face each other, the reflector can be made thinner.

  Moreover, as a preferable aspect of the present invention, it is desirable that the plurality of structures have a reflecting surface that deflects light from the light emitting portion by reflection. Thereby, the light incident on the planar deflection unit can be efficiently advanced in the direction of the irradiated surface.

  Moreover, as a preferable aspect of the present invention, it is desirable that the plurality of structures constitute a blazed structure having a sawtooth cross section. Thereby, light can be deflected by reflection.

  Moreover, as a preferable aspect of the present invention, it is desirable that the reflecting surface has a curved surface that is curved in cross section. Thereby, light can be advanced more efficiently in the direction of the irradiated surface.

  Moreover, as a preferable aspect of the present invention, it is desirable that the plurality of structures constitute a Fresnel structure having a cross section having substantially the same shape as the cross section of the Fresnel lens. Thereby, light can be advanced more efficiently in the direction of the irradiated surface.

  Moreover, as a preferable aspect of the present invention, it is desirable that the plurality of structures have a curved shape in a plane. Thereby, light can be advanced in the direction of the central axis.

  Moreover, as a preferable aspect of the present invention, it is desirable that the rotation curved surface is a rotation ellipsoid obtained by rotating an ellipse around the central axis. Thereby, light can be efficiently advanced in the direction of the central axis.

  Further, as a preferable aspect of the present invention, when the ellipse is defined with reference to the first focus and the second focus, and the light emitting unit is arranged in the vicinity of the first focus or the first focus, the plurality of structures are: In the plane, it is desirable to arrange them substantially concentrically around the position corresponding to the second focus or the vicinity of the position corresponding to the second focus. Thereby, light can be advanced more efficiently in the direction of the central axis.

  Furthermore, a light source device according to the present invention includes a light emitting unit that emits light, and the reflector. By using the reflector described above, it is possible to reduce the thickness and to efficiently advance light to the irradiated surface. As a result, a light source device that is thin and capable of supplying light efficiently can be obtained.

  Furthermore, a projector according to the present invention includes the light source device described above and a spatial light modulation device that modulates light emitted from the light source device in accordance with an image signal. By using the above light source device, it is possible to reduce the thickness and supply light efficiently. Thereby, it is possible to obtain a thin projector that can efficiently display a bright image.

The figure which shows the perspective structure of the light source device which concerns on Example 1 of this invention. The figure which shows the cross-sectional structure of the light source device in the plane containing a central axis. The figure which shows the front structure of the reflector in the plane orthogonal to a central axis. The figure which represented typically the principal part cross-section structure of the 1st plane deflection | deviation part. The figure which represented typically the principal part plane structure of the 1st plane deflection | deviation part. The figure explaining the behavior of the light inject | emitted from the light emission part. The figure of the principal part cross-section structure of the 1st plane deflection | deviation part of the reflector which concerns on Example 2 of this invention. FIG. 10 is a diagram illustrating a cross-sectional configuration of a main part of a first planar deflection unit according to Modification 1 of Example 2. FIG. 10 is a diagram illustrating a cross-sectional configuration of a main part of a first planar deflection unit according to a second modification of the second embodiment. FIG. 10 is a diagram illustrating a cross-sectional configuration of a main part of a first planar deflection unit according to Modification 3 of Example 2. FIG. 10 is a diagram illustrating a cross-sectional configuration of a main part of a first plane deflection unit according to Modification 4 of Example 2. FIG. 10 is a diagram schematically illustrating a first planar deflection unit according to Modification Example 5 of Example 2. The figure which shows the cross-sectional structure of the light source device which concerns on Example 3 of this invention. The figure explaining the behavior of the light inject | emitted from the light emission part. FIG. 10 is a diagram illustrating a schematic configuration of a projector according to a fourth embodiment of the invention.

  Embodiments of the present invention will be described below in detail with reference to the drawings.

  FIG. 1 shows a perspective configuration of a light source device 10 according to Embodiment 1 of the present invention. The light source device 10 includes an arc tube 11 and a reflector 12. The arc tube 11 is, for example, an ultra high pressure mercury lamp. The arc tube 11 includes a light emitting unit 13 that emits light. It is assumed that the light emitting unit 13 is disposed on the central axis AX of the light source device 10. The reflector 12 is provided around the central axis AX. The reflector 12 has a concave shape having an opening on the side opposite to the side where the arc tube 11 is provided.

  The inner surface of the reflector 12 is constituted by a first plane deflection unit 14, a second plane deflection unit 15, and a curved surface reflection unit 16. The first planar deflection unit 14 is provided on a part of the inner surface of the reflector 12 on the opening side of the reflector 12. The second plane deflection unit 15 is provided at a position facing the first plane deflection unit 14 via the central axis AX. The first plane deflection unit 14 and the second plane deflection unit 15 are substantially parallel to the central axis AX. The first plane deflection unit 14 and the second plane deflection unit 15 are formed on planes having substantially the same size. The first plane deflection unit 14 and the second plane deflection unit 15 are plane deflection units that deflect light from the light emitting unit 13 forward. The curved reflection portion 16 is a portion of the inner surface of the reflector 12 other than the portion where the first plane deflection portion 14 is provided and the portion where the second plane deflection portion 15 is provided. The curved reflecting portion 16 has a curved shape. The curved reflection unit 16 reflects light from the light emitting unit 13.

  FIG. 2 shows a cross-sectional configuration of the light source device 10 in a plane that includes the central axis AX and is substantially perpendicular to the first plane deflection unit 14 and the second plane deflection unit 15. In the cross section shown in the drawing, the curved reflecting portion 16 has the same shape as an ellipse having the central axis AX as a major axis. The curved reflecting portion 16 has substantially the same shape as a spheroid surface obtained by rotating an ellipse around the central axis AX. The light emitting unit 13 is provided at a first focal point which is one of the focal points defining such an ellipse. The first plane deflection unit 14 and the second plane deflection unit 15 are formed substantially in parallel.

  FIG. 3 shows a front configuration of the reflector 12 in a plane orthogonal to the central axis AX. Here, the configuration of the reflector 12 will be described assuming a spheroid ellipsoid S1 obtained by rotating the ellipse around the central axis AX. In the illustrated plane, the spheroid ellipsoid S1 forms a circle centered on the central axis AX. The curved reflecting portion 16 has substantially the same shape as the spheroid ellipsoid S1. The first plane deflection unit 14 and the second plane deflection unit 15 are formed on a plane located on the center axis AX side with respect to the spheroid ellipsoid S1. The reflector 12 can be made thinner by providing the first plane deflector 14 and the second plane deflector 15 facing each other as compared with the case where only the spheroid S1 is provided. For example, when the optical axis of the optical system of the projector coincides with the central axis AX, the first plane deflection unit 14 and the second plane deflection unit 15 are substantially parallel to the optical axis of the optical system. The projector housing usually has an upper surface and a lower surface substantially parallel to the optical axis. By disposing the light source device 10 so that the first planar deflection unit 14 and the second planar deflection unit 15 are substantially parallel to the upper and lower surfaces, the projector housing can be made thin.

  FIG. 4 schematically illustrates a cross-sectional configuration of a main part of a portion of the reflector 12 where the first planar deflection unit 14 is provided. The cross section shown in the figure is assumed to be a plane that includes a center axis AX (not shown) and is orthogonal to the plane S2 on which the first plane deflection unit 14 is provided. The first plane deflection unit 14 includes a diffraction grating 17 provided on the plane S2. The diffraction grating 17 deflects the light from the light emitting unit 13 by diffraction. The diffraction grating 17 has a fine binary structure, for example. A fine binary structure is a parallel arrangement of a plurality of minute structures formed at a substantially constant height. Each structure constituting the diffraction grating 17 has a rectangular cross-sectional shape. The diffraction grating 17 is obtained by appropriately patterning a substantially flat layer formed on the plane S2. The diffraction grating 17 is configured using a highly reflective member such as a dielectric multilayer film or a metal film.

  FIG. 5 schematically shows the main plane configuration of the first plane deflection unit 14. The illustrated plane is assumed to be a plane parallel to the plane S2 on which the first plane deflection unit 14 is provided. The diffraction grating 17 is configured by aligning each structure formed substantially perpendicular to a center axis AX (not shown) in a direction along the center axis AX. The diffraction grating 17 changes the phase of light incident on each structure. The diffraction grating 17 generates diffracted light by spatially changing the phase of the light. By optimizing the surface conditions including the interval and height of the structures constituting the diffraction grating 17, the light incident on the first planar deflection unit 14 from the light emitting unit 13 can be advanced in a desired direction. The second plane deflection unit 15 includes a diffraction grating 17 formed in the same manner as the first plane deflection unit 14.

  FIG. 6 illustrates the behavior of light emitted from the light emitting unit 13. Here, a description will be given assuming that light emitted from the light source device 10 is incident on the concave lens 18. The optical axis of the concave lens 18 substantially coincides with the central axis AX of the light source device 10. The light emitted from the light emitting unit 13 is emitted toward the entire inner surface of the reflector 12. The curved reflecting section 16 advances the incident light in the direction toward the front side, that is, the side where the irradiated surface is present when viewed from the light emitting section 13. Specifically, the light emitted from the first focal point of the ellipse and reflected by the curved reflecting portion 16 travels toward the second focal point of the ellipse. By providing the light emitting unit 13 at the first focal point, light can efficiently travel in the direction from the curved reflecting unit 16 toward the second focal point on the central axis AX.

  The diffraction grating 17 (see FIGS. 4 and 5) formed in the first plane polarization unit 14 and the second plane polarization unit 15 has an illuminated surface when incident light is viewed from the front side, that is, the light emitting unit 13 by diffraction. It is formed to advance in the direction of the side. The light emitted from the light emitting unit 13 and incident on the first planar deflection unit 14 travels to the front side due to deflection by the first planar deflection unit 14. The light emitted from the light emitting unit 13 and incident on the second plane deflection unit 15 travels to the front side due to deflection by the second plane deflection unit 15. Preferably, the first plane polarization unit 14 and the second plane polarization unit 15 deflect incident light toward the second focal point on the central axis AX by diffraction at the diffraction grating 17. If a simple planar reflecting surface is used in place of the first planar deflecting unit 14 and the second planar deflecting unit 15, a large amount of light is not taken into the concave lens 18 and is lost, as indicated by the broken line arrows in the figure. It becomes. The light source device 10 of the present embodiment can efficiently deflect light in a desired direction by using the first planar deflection unit 14 and the second planar deflection unit 15. Further, by causing the light incident on the first plane deflecting unit 14 and the second plane polarizing unit 15 to travel forward without returning to the light emitting unit 13, a loss due to the light returning to the light emitting unit 13, for example, in the arc tube 11. Loss due to absorption and scattering is reduced, and light is efficiently advanced to the irradiated surface.

  The concave lens 18 collimates the light traveling in the direction from the light source device 10 toward the second focus. The reflector 12 efficiently travels light from the concave lens 18 to an irradiated surface (not shown) by causing the curved reflecting portion 16, the first plane deflecting portion 14, and the second plane deflecting portion 15 to efficiently travel light toward the second focal point. Light can travel well. Thereby, there is an effect that the reflector 12 can be made thin and light can be efficiently advanced to the irradiated surface.

  The curved reflecting portion 16 is obtained by vapor-depositing a highly reflective member such as a dielectric multilayer film or a metal member on the surface of a base material formed into a desired shape. The first plane deflection unit 14 and the second plane deflection unit 15 of the reflector 12 are obtained by forming the diffraction grating 17 on the surface of a flat substrate. As a base material for forming the curved reflection portion 16, the first flat deflection portion 14, and the second flat deflection portion 15, for example, heat resistant glass can be used. The reflector 12 can be manufactured by combining a base material on which the curved reflecting portion 16 is formed, a base material on which the first flat deflection portion 14 is formed, and a base material on which the second flat deflection portion 15 is formed. In addition, the 1st plane polarizing part 14 and the 2nd plane polarizing part 15 are not restricted to what deflects light toward the ellipse 2nd focus, What is necessary is just to deflect light at least to the front side.

  FIG. 7 shows a cross-sectional configuration of a main part of a portion of the reflector according to the second embodiment of the present invention where the first plane deflection unit 20 is provided. The cross section shown in the figure includes a center axis AX (not shown) and is orthogonal to the plane S2 on which the first plane deflection unit 20 is provided. The second plane deflection unit (not shown) has the same configuration as the first plane deflection unit 20. The reflector of the present embodiment has the same configuration as that of the reflector 12 of the first embodiment except for the first plane deflection unit 20 and the second plane deflection unit. The same parts as those in the first embodiment are denoted by the same reference numerals, and redundant description is omitted.

  The first plane deflection unit 20 includes a blaze structure 21 provided on the plane S2. The blaze structure 21 has a sawtooth cross section. The blaze structure 21 is configured by arranging a plurality of minute structures having a triangular cross section in parallel. The minute structure constituting the blaze structure 21 includes a first surface 22 and a second surface 23. As with the diffraction grating 17 (see FIG. 5) in the first embodiment, the blaze structure 21 has the structures formed substantially perpendicular to the center axis AX (not shown) arranged in parallel in the direction along the center axis AX. Configured. The blaze structure 21 is obtained by appropriately patterning a substantially flat layer formed on the plane S2.

  The reflection surface 24 is formed on the first surface 22 of the blazed structure 21. The first surface 22 is inclined with respect to the plane S2. The second surface 23 is formed between the first surfaces 22. The first surface 22 and the second surface 23 are substantially flat surfaces. The reflection surface 24 deflects light from the light emitting unit 13 (see FIG. 2) by reflection. The direction in which the first surface 22 is inclined is set so that the side farther from the opening is away from the plane S2 than the side closer to the opening of the reflector. As a result, the reflection surface 24 is formed so that the incident light travels in the direction of the front side, that is, the irradiated surface side when viewed from the light emitting unit 13 by reflection. The reflection surface 24 can be formed by vapor-depositing a highly reflective member such as a dielectric multilayer film or a metal film on the first surface 22 of the blazed structure 21. The light emitted from the light emitting unit 13 and incident on the first plane deflection unit 20 travels to the front side due to deflection by the first plane deflection unit 20. Preferably, the first plane deflection unit 20 and the second plane deflection unit deflect incident light toward the second focal point on the central axis AX (see FIG. 1) by reflection on the reflection surface 24. In the case of this modification as well, the reflector can be made thin and light can efficiently travel to the irradiated surface.

  FIG. 8 shows a cross-sectional configuration of the main part of a portion of the reflector according to the first modification of the present embodiment where the first plane deflection unit 25 is provided. The blaze structure 26 constituting the first plane deflection unit 25 includes a concave first surface 27. The reflection surface 28 is formed on the first surface 27 of the blazed structure 26. The reflecting surface 28 is a curved surface that forms a curve in the illustrated cross section. The cross section shown in the figure is a plane that includes a center axis AX (not shown) and is orthogonal to the plane S2 on which the first plane deflection unit 25 is provided. The shape of the first surface 27 can be determined as appropriate so that light efficiently travels to the front side, preferably the second focal point on the central axis AX.

  FIG. 9 illustrates a cross-sectional configuration of a main part of a portion where the first plane deflection unit 30 is provided in the reflector according to the second modification of the present embodiment. The blaze structure 31 constituting the first planar deflection unit 30 includes a convex first surface 32. The reflection surface 33 is formed on the first surface 32 of the blazed structure 31. The reflecting surface 33 is a curved surface that forms a curve in the illustrated cross section. The cross section shown in the figure is a plane that includes a center axis AX (not shown) and is orthogonal to the plane S2 on which the first plane deflection unit 30 is provided. The shape of the first surface 32 can be determined as appropriate so that light efficiently travels to the front side, preferably the second focal point on the central axis AX. As will be described with reference to FIGS. 8 and 9, by appropriately deforming the reflecting surfaces 28 and 33, it is possible to make light travel more efficiently in the direction of the irradiated surface. The first surface 27 in the first modification and the first surface 32 in the second modification are not limited to being configured by only a curved surface, and for example, have a configuration including a plurality of planes or a configuration including a curved surface and a plane. May be. In any of the blaze structures described in the present embodiment, the pitch at which the structures are arranged in parallel and the shape of each structure, for example, the inclination and curvature of the first surface are not limited to being constant, and are directed to the irradiated surface. You may change suitably considering the efficiency which advances light.

  FIG. 10A illustrates a cross-sectional configuration of a main part of a portion of the reflector according to the third modification of the present embodiment where the first plane deflection unit 35 is provided. The cross section shown in the figure includes a center axis AX (not shown) and is orthogonal to the plane S2 on which the first plane deflection unit 35 is provided. The 1st plane deflection | deviation part 35 has the Fresnel structure 36 provided in plane S2. The Fresnel structure 36 is configured by juxtaposing a plurality of minute structures having a cross section having substantially the same shape as a cross section of a section obtained by cutting a convex surface of a convex lens into a ring shape. The Fresnel structure 36 is a structure having a cross section having substantially the same shape as the cross section of the Fresnel lens. Here, the cross section of the Fresnel lens is a cross section when cut along a plane along the diameter of the lens, and the cross section of the Fresnel structure 36 is cut along a plane including the central axis AX and orthogonal to the plane S2. It is a cross section in the case of doing.

  The minute structure constituting the Fresnel structure 36 includes a first surface 37 and a second surface 38. The first surface 37 is a convex curved surface. The reflection surface 39 is formed on the first surface 37 of the Fresnel structure 36. The reflecting surface 39 is a curved surface that forms a curve in the illustrated cross section. The reflective surface 39 can be formed by depositing a highly reflective member such as a dielectric multilayer film or a metal film on the first surface 37 of the Fresnel structure 36. The light emitted from the light emitting unit 13 (see FIG. 2) and incident on the first plane deflection unit 35 travels forward due to the deflection at the first plane deflection unit 35. Preferably, the first plane deflection unit 35 and the second plane deflection unit deflect incident light toward the second focal point on the central axis AX by reflection on the reflection surface 39. In the case of this modification as well, the reflector can be made thin and light can efficiently travel to the irradiated surface. In the Fresnel structure 36, the first surface 37 on which the reflection surface 39 is formed out of the first surface 37 and the second surface 38 may have the same shape as the cross section of the Fresnel lens.

  FIG. 10-2 illustrates a cross-sectional configuration of a main part of a portion of the reflector according to the fourth modification of the present embodiment in which the first plane deflection unit 80 is provided. The cross section shown in the figure includes a center axis AX (not shown) and is orthogonal to the plane S2 on which the first plane deflection unit 80 is provided. The Fresnel structure 81 formed in the first plane deflection unit 80 has a plurality of minute cross sections having substantially the same shape as the cross section of the slice obtained by cutting the spheroid ellipsoid S1 (see FIG. 3) of the curved reflection unit 16 into a ring shape. It is configured with parallel structures. The cross section of the curved reflecting portion 16 and the cross section of the Fresnel structure 81 are both cross sections when cut along a plane that includes the central axis AX and is orthogonal to the plane S2.

  The minute structure constituting the Fresnel structure 81 includes a first surface 82 and a second surface 83. The first surface 82 is a concave curved surface. The reflection surface 84 is formed on the first surface 82 of the Fresnel structure 81. The light emitted from the light emitting unit 13 (see FIG. 2) and incident on the first plane deflection unit 80 travels forward due to the deflection at the first plane deflection unit 80. Preferably, the first plane deflection unit 80 and the second plane deflection unit deflect incident light toward the second focal point on the central axis AX by reflection on the reflection surface 84. In the case of this modification as well, the reflector can be made thin and light can efficiently travel to the irradiated surface. When the first surface 82 is a concave curved surface, it is possible to efficiently advance the light toward the second focal point by improving the light collecting property of the light reflected by the reflecting surface 84. Of the first surface 82 and the second surface 83, the Fresnel structure 81 may have the same shape as the cross section of the spheroid ellipsoid S <b> 1 of the curved reflecting portion 16.

  When the slices obtained by cutting out the spheroid ellipsoid S1 in a ring shape are translated in parallel on the plane S2, a shift occurs between the focal position of the original spheroid ellipsoid S1 and the focal position of each slice. It is desirable that the Fresnel structure 81 is appropriately adjusted in shape so that not only the slices of the shape obtained by cutting the spheroid ellipsoid S1 in a ring shape but also the focal position shift is corrected. For example, by appropriately adjusting the curvature of the first surface 82 with respect to the original spheroid S1, light can be efficiently advanced to a desired direction, specifically the second focus.

  In the Fresnel structure 81, the concave shape of the first surface 82 described in this modification may be reversed, and the first surface may be a convex curved surface. When the first surface is a convex curved surface, it is possible to make the light travel further by improving the light divergence.

  FIG. 11 schematically shows a main part plane configuration of the first plane deflection unit 40 in the reflector according to the fifth modification of the present embodiment. The illustrated plane is assumed to be a plane parallel to the plane S2 on which the first plane deflection unit 40 is provided. The second plane deflection unit (not shown) has the same configuration as the first plane deflection unit 40. The blaze structure 41 constituting the first plane deflection unit 40 has a curved shape in the plane shown. The blaze structure 41 is arranged concentrically around a predetermined position F corresponding to the second focal point. The position F is assumed to be a position obtained by projecting the second focal point of the ellipse formed by the curved reflecting portion 16 (see FIG. 2) of the reflector onto the plane S2.

  The first plane deflection unit 40 can advance light in a direction toward the second focal point on the central axis AX not only in a plane orthogonal to the plane S2 but also in a plane parallel to the plane S2. Thereby, light can be advanced to the irradiated surface more efficiently. Not only the case where the blazed structure 41 is used, but also the above-mentioned Fresnel structure 36 (see FIG. 10A) may be arranged concentrically around the position F.

  FIG. 12 shows a cross-sectional configuration of a light source device 50 according to Embodiment 3 of the present invention. The cross section shown is a plane that includes the central axis AX and is substantially perpendicular to the first plane deflection unit 52 and the second plane deflection unit 53. The same parts as those in the first embodiment are denoted by the same reference numerals, and redundant description is omitted. The light source device 50 includes the arc tube 11 and the reflector 51. The reflector 51 is provided around the central axis AX. The reflector 51 has a concave shape having an opening on the side opposite to the side where the arc tube 11 is provided.

  The inner surface of the reflector 51 is composed of a first plane deflection unit 52, a second plane deflection unit 53, and a curved surface reflection unit 54. The first planar deflection unit 52 is provided on a part of the inner surface of the reflector 51 on the opening side of the reflector 51. The second plane deflection unit 53 is provided at a position facing the first plane deflection unit 52 via the central axis AX. The first plane deflection unit 52 and the second plane deflection unit 53 are substantially parallel to the central axis AX. The first plane deflection unit 52 and the second plane deflection unit 53 are plane deflection units that deflect light from the light emitting unit 13. The first plane deflection unit 52 and the second plane deflection unit 53 have a diffraction grating (not shown) that deflects light from the light emitting unit 13 by diffraction. The first plane deflection unit 52 and the second plane deflection unit 53 can be configured in the same manner as the first plane deflection unit 14 in the first embodiment.

  The curved reflection portion 54 is a portion other than the portion where the first plane deflection unit 52 is provided and the portion where the second plane deflection unit 53 is provided on the inner surface of the reflector 51. The curved reflecting portion 54 has a curved surface shape. The curved surface reflection part 54 reflects the light from the light emitting part 13. In the cross section shown in the drawing, the curved reflecting portion 54 has substantially the same shape as a parabola with the central axis AX as the axis of symmetry. The curved reflecting portion 54 has substantially the same shape as a rotating paraboloid obtained by rotating a parabola around the central axis AX. The light emitting unit 13 is provided at a focal point that defines such a parabola.

  Here, the configuration of the reflector 51 will be described assuming a rotating paraboloid obtained by rotating a parabola around the central axis AX. In the plane orthogonal to the central axis AX, the paraboloid of revolution forms a circle centered on the central axis AX, as with the spheroid ellipsoid S1 shown in FIG. The curved reflection part 54 has substantially the same shape as a part of the paraboloid of revolution. The 1st plane deflection part 52 and the 2nd plane deflection part 53 are formed in the plane located in the central-axis AX side with respect to parts other than the part in which the curved-surface reflection part 54 was provided among rotation parabolas. The reflector 51 can be made thinner by providing the first plane deflecting unit 52 and the second plane deflecting unit 53 facing each other as compared with the case where only the same shape as the rotary paraboloid is used.

  FIG. 13 illustrates the behavior of light emitted from the light emitting unit 13. The light emitted from the focal point of the parabola and reflected by the curved reflecting portion 54 travels substantially parallel to the central axis AX. By providing the light emitting unit 13 at the focal point, it is possible to efficiently advance light in a direction from the curved surface reflection unit 54 toward the irradiated surface (not shown). The light emitted from the light emitting unit 13 and incident on the first plane deflection unit 52 travels substantially parallel to the central axis AX due to the deflection by the first plane deflection unit 52. The light emitted from the light emitting unit 13 and incident on the second plane deflection unit 53 travels substantially parallel to the central axis AX due to deflection by the second plane deflection unit 53.

  The reflector 51 can cause light to efficiently travel to the surface to be irradiated by the curved surface reflection portion 54, the first plane deflection portion 52, and the second plane deflection portion 53. Thereby, also in the case of a present Example, the reflector 51 can be made thin and light can be efficiently advanced to an irradiated surface. The light source device 50 of this embodiment can emit light substantially parallel to the central axis AX without using a concave lens. Therefore, compared with the light source device 10 according to the first embodiment, there is an advantage that the number of parts can be reduced. The reflector 12 of the first embodiment having the ellipsoidal surface has an advantage that it can be easily reduced in thickness as compared with the reflector 51 of the present embodiment having the rotating paraboloid. Also in the case of the present embodiment, the first plane deflection unit 52 and the second plane deflection unit 53 are not limited to those having a diffraction grating, but have reflection surfaces provided on a blaze structure or a Fresnel structure. Also good.

  The reflector described in each of the above embodiments includes a first plane deflection unit and a second plane deflection unit, but is not limited thereto. The reflector only needs to have at least one plane deflection unit. By using at least one plane deflection unit, it is possible to obtain an effect of thinning the reflector as compared with the case where only the shape substantially the same as that of the spheroid or paraboloid is used. The curved reflection part is not limited to a part of the spheroid or part of the paraboloid of revolution, and other rotations obtained by rotating a predetermined curve around the central axis AX. The shape may be substantially the same as a part of the curved surface. Further, the curved reflecting portion may have a free curved surface obtained by deforming the rotating curved surface.

  The arc tube 11 used in the light source device of each of the above embodiments is not limited to an ultrahigh pressure mercury lamp, and may be another lamp such as a metal halide lamp, a halogen lamp, a xenon lamp, or the like. The light source device is not limited to one having a lamp, and may be configured to use a solid light source such as a light emitting diode (LED) or a super luminescence diode (SLD).

  FIG. 14 shows a schematic configuration of a projector 60 according to Embodiment 4 of the present invention. The projector 60 is a front projection type projector that projects light onto a screen (not shown) and observes an image by observing light reflected from the screen. The projector 60 includes the light source device 10 according to the first embodiment. The light source device 10 emits light including red (R) light, green (G) light, and blue (B) light. The concave lens 18 collimates the light emitted from the light source device 10. The first integrator lens 61 and the second integrator lens 62 have a plurality of lens elements arranged in an array. The first integrator lens 61 divides the light beam from the concave lens 18 into a plurality of parts. Each lens element of the first integrator lens 61 condenses the light beam from the concave lens 18 in the vicinity of the lens element of the second integrator lens 62. The lens element of the second integrator lens 62 forms an image of the lens element of the first integrator lens 61 on the spatial light modulator.

  Light that has passed through the two integrator lenses 61 and 62 is converted into linearly polarized light in a specific vibration direction by the polarization conversion element 63. The superimposing lens 64 superimposes the image of each lens element of the first integrator lens 61 on the spatial light modulator. The first integrator lens 61, the second integrator lens 62, and the superimposing lens 64 make the intensity distribution of light from the light source device 10 uniform on the spatial light modulator. The light from the superimposing lens 64 enters the first dichroic mirror 65. The first dichroic mirror 65 reflects R light and transmits G light and B light. The R light incident on the first dichroic mirror 65 has its optical path bent by the first dichroic mirror 65 and the reflection mirror 66, and enters the R light field lens 67R. The R light field lens 67R collimates the R light from the reflection mirror 66 and makes it incident on the R light spatial light modulator 68R.

  The spatial light modulator 68R for R light is a spatial light modulator that modulates R light according to an image signal, and is a transmissive liquid crystal display device. A liquid crystal panel (not shown) provided in the R light spatial light modulation device 68R encloses a liquid crystal layer for modulating light according to an image signal between two transparent substrates. The R light modulated by the R light spatial light modulator 68R is incident on a cross dichroic prism 69 which is a color synthesis optical system.

  The G light and B light that have passed through the first dichroic mirror 65 enter the second dichroic mirror 70. The second dichroic mirror 70 reflects G light and transmits B light. The G light incident on the second dichroic mirror 70 has its optical path bent by the second dichroic mirror 70 and is incident on the G light field lens 67G. The G light field lens 67G collimates the G light from the second dichroic mirror 70 and makes it incident on the G light spatial light modulator 68G. The G light spatial light modulator 68G is a spatial light modulator that modulates the G light according to an image signal, and is a transmissive liquid crystal display device. The G light modulated by the G light spatial light modulator 68G is incident on a different surface of the cross dichroic prism 69 from the surface on which the R light is incident.

  The B light transmitted through the second dichroic mirror 70 is transmitted through the relay lens 71, and then the optical path is bent by reflection at the reflection mirror 72. The B light from the reflection mirror 72 further passes through the relay lens 73, and then the optical path is bent by reflection by the reflection mirror 74, and enters the B light field lens 67B. Since the optical path of the B light is longer than the optical path of the R light and the optical path of the G light, relay lenses 71 and 73 are provided in the optical path of the B light in order to make the illumination magnification in the spatial light modulator equal to that of other color lights. The relay optical system to be used is adopted.

  The B light field lens 67B collimates the B light from the reflection mirror 74 and makes it incident on the B light spatial light modulator 68B. The B light spatial light modulator 68B is a spatial light modulator that modulates B light in accordance with an image signal, and is a transmissive liquid crystal display device. The B light modulated by the B light spatial light modulator 68B is incident on a surface of the cross dichroic prism 69 that is different from the surface on which the R light is incident and the surface on which the G light is incident.

  The cross dichroic prism 69 has two dichroic films 75 and 76 that are substantially orthogonal to each other. The first dichroic film 75 reflects R light and transmits G light and B light. The second dichroic film 76 reflects B light and transmits R light and G light. The cross dichroic prism 69 combines R light, G light, and B light incident from different directions and emits the light toward the projection lens 77. The projection lens 77 projects the light combined by the cross dichroic prism 69 toward the screen.

  By using the light source device 10 described above, the projector 60 can be made thin, and can efficiently supply light to the irradiated surfaces of the spatial light modulators 68R, 68G, and 68B for each color light. Thereby, there is an effect that it is possible to display a thin and efficient bright image. Since the projector 60 can be made thin, it can be excellent in portability and installability. The projector 60 may use any of the light source devices of the above embodiments.

  The projector 60 according to the present invention is not limited to the case where a transmissive liquid crystal display device is used as the spatial light modulation device. As the spatial light modulator, a reflective liquid crystal display (Liquid Crystal On Silicon; LCOS), DMD (Digital Micromirror Device), GLV (Grating Light Valve), or the like may be used. The projector 60 is not limited to a configuration including a spatial light modulator for each color light. The projector 60 may be configured to modulate two or three or more color lights with one spatial light modulator. The projector 60 is not limited to the case where a spatial light modulator is used. The projector 60 may be a slide projector that uses a slide having image information. The projector 60 may be a so-called rear projector that supplies light to one surface of the screen and observes an image by observing light emitted from the other surface of the screen. The light source device according to the present invention is not limited to that used for the projector 60. The light source device may be applied to, for example, a lighting device such as a flashlight or a headlight of an automobile.

  As described above, the reflector according to the present invention is useful when used in a light source device of a projector.

  DESCRIPTION OF SYMBOLS 10 Light source device, 11 Light emission tube, 12 Reflector, 13 Light emission part, 14 1st plane deflection part, 15 2nd plane deflection part, 16 Curved surface reflection part, AX center axis | shaft, S1 Spheroid, 17 Diffraction grating, S2 plane, 18 concave lens, 20 first plane deflector, 21 blazed structure, 22 first surface, 23 second surface, 24 reflective surface, 25 first plane deflector, 26 blazed structure, 27 first surface, 28 reflective surface, 30 First plane deflector, 31 Blaze structure, 32 First surface, 33 Reflective surface, 35 First plane deflector, 36 Fresnel structure, 37 First surface, 38 Second surface, 39 Reflective surface, 40 First Plane deflection unit, 41 Blaze structure, 50 light source device, 51 reflector, 52 first plane deflection unit, 53 second plane deflection unit, 54 curved surface reflection unit, 60 projector, 61 first interface 62 lens, 62 second integrator lens, 63 polarization conversion element, 64 superimposing lens, 65 first dichroic mirror, 66 reflecting mirror, 67R field lens for R light, 67G field lens for G light, 67B field lens for B light, 68R Spatial light modulator for R light, spatial light modulator for 68G G light, spatial light modulator for 68B B light, 69 cross dichroic prism, 70 second dichroic mirror, 71, 73 relay lens, 72, 74 reflection mirror, 75 1st dichroic film, 76 2nd dichroic film, 77 projection lens, 80 1st plane deflection | deviation part, 81 Fresnel structure, 82 1st surface, 83 2nd surface, 84 reflective surface.

Claims (7)

A reflector provided around a central axis where the light emitting unit is arranged, used in combination with a light emitting unit that emits light,
A curved ellipsoid having substantially the same shape as a spheroid obtained by rotating an ellipse around the central axis, and reflecting light from the light emitting portion;
A plane deflection unit provided on the center axis side with respect to the spheroid ,
The planar deflection unit includes a plurality of structures having a reflection surface that reflects light from the light emitting unit to the front side ,
In the case where the light emitting unit is disposed at the first focal point of the ellipse or in the vicinity of the first focal point, the plurality of structures are located at positions corresponding to the second focal point of the ellipse in the planar deflection unit, or the A reflector, characterized in that the reflector is disposed substantially concentrically around a position corresponding to the second focal point .   2. The planar deflection unit includes a first planar deflection unit and a second planar deflection unit provided at a position facing the first planar deflection unit via the central axis. Reflector as described in. Wherein the plurality of structures, a reflector according to claim 1 or 2, characterized in that it constitutes a blaze structure with a cross section of saw-tooth shape. The reflector according to claim 3 , wherein the reflecting surface has a curved surface that is curved in the cross section. The reflector according to claim 1 or 2 , wherein the plurality of structures constitute a Fresnel structure having a cross section having substantially the same shape as a cross section of the Fresnel lens. A light emitting unit for emitting light;
It has a reflector as described in any one of Claims 1-5 , The light source device characterized by the above-mentioned. The light source device according to claim 6 ;
And a spatial light modulation device that modulates light emitted from the light source device in accordance with an image signal.

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