JP2008233597A - Projector - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a projector which can be miniaturized. <P>SOLUTION: The projector 1000 is equipped with: an illumination device 100; a color separation optical system 200 which separates light from the illumination device 100 into three color lights and guides the color lights to areas to be illuminated; liquid crystal devices 400R, 400G and 400B which modulate the three color lights separated by the color separation optical system 200, according to image information, respectively; a cross dichroic prism 500 which combines the respective color lights modulated by the liquid crystal devices; and a projection optical system 600 which projects image light combined by the cross dichroic prism 500. The color separation optical system 200 has a reflecting prism 340 which is arranged in the optical path of the blue light of the three color lights and reflects the light from the illumination device 100 toward the liquid crystal device 400B. An incident side polarizing plate 410B is stuck to the light emitting surface of the reflecting prism 340 and a condenser lens 430B is stuck to the light incident surface of the reflecting prism 340. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a projector.

  Conventionally, an illumination device, a color separation optical system having two dichroic mirrors and three reflection mirrors, and three liquid crystal devices that modulate each color light guided by the color separation optical system according to image information, respectively. A projector is known (for example, see Patent Document 1). A condensing lens and an incident side polarizing plate are respectively arranged on the light incident side of each liquid crystal device, and an emission side polarizing plate is arranged on the light emitting side of each liquid crystal device. The color separation optical system is configured to separate the light from the illumination device into, for example, three color lights of red light, green light, and blue light and guide the light to each liquid crystal device.

JP 2003-215702 A

  By the way, in recent years, there is a demand for miniaturizing a projector.

  However, in a conventional projector, a condensing lens (field lens) having a predetermined thickness between a liquid crystal device and a reflecting mirror arranged to reflect light toward the liquid crystal device is also Since the incident-side polarizing plate to which the substrate having a thickness is attached is disposed, a predetermined space must be secured between the liquid crystal device and the reflection mirror (a portion in front of the liquid crystal device). For this reason, it is not easy to reduce the planar size of the color separation optical system, and it is not easy to reduce the size of the projector.

  Therefore, the present invention has been made in view of such circumstances, and an object thereof is to provide a projector that can be miniaturized.

  The projector of the present invention is separated by an illumination device that emits an illumination light beam, a color separation optical system that separates light from the illumination device into a plurality of color lights, and guides the light to an illuminated area, and the color separation optical system. A plurality of liquid crystal devices that modulate the plurality of color lights according to image information, a color combining optical system that combines the color lights modulated by the plurality of liquid crystal devices, and an image combined by the color combining optical system A projection optical system that projects light, and the color separation optical system is disposed in an optical path of at least one of the plurality of color lights, and reflects light from the illumination device toward the liquid crystal device An incident-side polarizing plate is attached to one of the light incident surface and the light exit surface of the reflecting prism, and a condenser lens is attached to the other surface of the reflecting prism. ing And wherein the door.

  For this reason, according to the projector of the present invention, a reflection prism is provided instead of a reflection mirror as a reflection element that reflects light toward the liquid crystal device, and an incident-side polarizing plate and a light incident surface and a light emission surface of the reflection prism are provided. Since the condensing lens is attached, the space in front of the liquid crystal device can be reduced. As a result, the planar size of the color separation optical system can be reduced, and the projector can be reduced in size.

When the condenser lens is disposed in front of the reflecting mirror while using the reflecting mirror as the reflecting element, a predetermined value conventionally required between the liquid crystal device and the reflecting mirror (portion before the liquid crystal device) is used. It is thought that the space of the can be reduced somewhat. However, in this case, the optical path length from the condenser lens to the liquid crystal device becomes long, and it becomes difficult to ensure the telecentricity of the condenser lens.
On the other hand, according to the projector of the present invention, since the reflecting element is provided with the reflecting prism instead of the reflecting mirror, even when the collecting lens is attached to the light incident surface of the reflecting prism, Since light passes through the prism medium, not in the air, the air equivalent optical path length is shortened. As a result, it is possible to secure the telecentricity of the condenser lens while reducing the size of the projector.

  Further, according to the projector of the present invention, since the condenser lens, the reflecting prism, and the incident-side polarizing plate are attached to each other, undesirable reflection at the interface of each member does not occur, and the light transmittance is increased. It becomes possible.

  Further, according to the projector of the present invention, since the incident-side polarizing plate and the condenser lens are attached to the reflecting prism, these three parts can be unitized, and the number of parts of the projector can be reduced. It becomes possible.

  Further, according to the projector of the present invention, since the reflecting prism has a relatively large heat capacity, it is possible to suppress the temperature rise of the incident-side polarizing plate attached to the reflecting prism, thereby improving the heat dissipation performance of the projector. Can do.

  In the projector according to the aspect of the invention, the color separation optical system may further include a relay optical system that guides one color light of the plurality of color lights to an illuminated area, and the reflection prism passes through the relay optical system. It is preferable to arrange in the optical path of colored light.

  When the color separation optical system has a relay optical system, the planar size generally tends to increase. However, by configuring as described above, the planar size of the color separation optical system can be reduced. A projector having an optical system can also be reduced in size.

  In the projector according to the aspect of the invention, the illumination device and the color separation optical system are arranged in a positional relationship such that a long side direction of the illumination device and a long side direction of the color separation optical system are substantially the same on a horizontal plane. It is preferable that

  When the present invention is applied to a projector in which the illumination device and the color separation optical system are arranged in the above positional relationship, the length in the long side direction of the entire projector can be shortened, so that the effect is particularly great. .

  In the projector according to the aspect of the invention, it is preferable that the projector further includes an attitude adjustment device capable of adjusting the attitude of the reflecting prism.

  With this configuration, it is possible to finely adjust the posture (arrangement angle, etc.) of the reflecting prism and adjust the position of the light applied to the image forming area of the liquid crystal device.

  The projector of the present invention will be described below based on the embodiments shown in the drawings.

[Embodiment 1]
FIG. 1 is a diagram illustrating an optical system of a projector 1000 according to the first embodiment.

  In the following description, the three directions orthogonal to each other are the z-axis direction (illumination optical axis OC direction in FIG. 1), the x-axis direction (direction parallel to the paper surface in FIG. 1 and perpendicular to the z-axis), and the y-axis direction. (A direction perpendicular to the paper surface in FIG. 1 and perpendicular to the z-axis).

  As shown in FIG. 1, the projector 1000 according to the first embodiment separates the illumination device 100 and the illumination light flux from the illumination device 100 into three color lights of red light, green light, and blue light and guides them to the illumination area. A color separation optical system 200 that emits light, three liquid crystal devices 400R, 400G, and 400B that modulate each of the three color lights separated by the color separation optical system 200 according to image information, and three liquid crystal devices 400R, 400G, Cross dichroic prism 500 as a color synthesis optical system that synthesizes the color light modulated by 400B, projection optical system 600 that projects the light synthesized by cross dichroic prism 500 onto a projection surface such as a screen SCR, and a reflection prism described later The projector includes an attitude adjustment device 350 capable of adjusting the attitude of 340.

  The illuminating device 100 includes a light source device 110 that emits an illumination light beam toward the illuminated region side, and a first plurality of first small lenses 122 that divide the illumination light beam emitted from the light source device 110 into a plurality of partial light beams. The lens array 120, the second lens array 130 having a plurality of second small lenses 132 corresponding to the plurality of first small lenses 122 of the first lens array 120, and the polarization directions of the partial light beams from the second lens array 130 And a superimposing lens 150 as a superimposing optical system that superimposes each partial light beam from the polarization converting element 140 in an illuminated area.

  The light source device 110 includes an ellipsoidal reflector 114, an arc tube 112 having a light emission center near the first focal point of the ellipsoidal reflector 114, and light emitted from the arc tube 112 toward the illuminated region side to the arc tube 112. It has a secondary mirror 116 that reflects toward it and a concave lens 118. The light source device 110 emits a light beam having the illumination optical axis OC as a central axis.

  The arc tube 112 has a tube bulb portion and a pair of sealing portions extending on both sides of the tube bulb portion. The tube portion is made of quartz glass formed in a spherical shape, and includes a pair of electrodes disposed in the tube portion, mercury, a rare gas, and a small amount of halogen sealed in the tube portion. As the arc tube 112, various arc tubes can be employed, for example, a metal halide lamp, a high pressure mercury lamp, an ultrahigh pressure mercury lamp, or the like.

  The ellipsoidal reflector 114 includes a cylindrical neck that is inserted and fixed to one sealing portion of the arc tube 112, and a reflective concave surface that reflects light emitted from the arc tube 112 toward the second focal position. Have

  The secondary mirror 116 is a reflecting means that covers substantially half of the bulb portion of the arc tube 112 and is disposed to face the reflective concave surface of the elliptical reflector 114. The sub mirror 116 is inserted and fixed to the other sealing portion of the arc tube 112. The secondary mirror 116 returns the light emitted from the arc tube 112 that does not go to the ellipsoidal reflector 114 to the arctube reflector 114 and makes it incident on the ellipsoidal reflector 114.

  The concave lens 118 has a function as a collimating lens that emits the focused light from the ellipsoidal reflector 114 as substantially parallel light, and is configured to emit the light from the ellipsoidal reflector 114 toward the first lens array 120. Has been.

  The first lens array 120 has a function as a light beam splitting optical element that splits light from the concave lens 118 into a plurality of partial light beams, and a plurality of first small lenses 122 are arranged in a plane orthogonal to the illumination optical axis OC. It has a configuration arranged in a matrix of rows and columns. Although not illustrated, the outer shape of the first small lens 122 is similar to the outer shape of the image forming area of the liquid crystal devices 400R, 400G, and 400B.

  The second lens array 130 has a function of forming an image of each first small lens 122 of the first lens array 120 in the vicinity of the image forming area of the liquid crystal devices 400R, 400G, and 400B together with the superimposing lens 150. The second lens array 130 has substantially the same configuration as the first lens array 120, and a plurality of second small lenses 132 are arranged in a matrix of a plurality of rows and a plurality of columns in a plane orthogonal to the illumination optical axis OC. Have a configuration.

  The polarization conversion element 140 transmits the light related to one polarization component of the light from the second lens array 130 and reflects the light related to the other polarization component, and the other reflected by the polarization separation surface. A reflection surface that reflects light related to the polarization component in a direction parallel to the light related to one polarization component that has passed through the polarization separation surface, and a light that is disposed at a position corresponding to the polarization separation surface. And a phase difference plate that converts the light into light related to the other polarization component.

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

  The color separation optical system 200 includes dichroic mirrors 210 and 220, a reflection mirror 230, and a relay optical system 300. The color separation optical system 200 separates the illumination light beam emitted from the superimposing lens 150 into three color lights of red light, green light, and blue light, and the red light, green light, and blue light are liquid crystal devices 400R, 400G, It has a function leading to 400B.

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

  The light of the red light component reflected by the dichroic mirror 210 is bent by the reflection mirror 230, passes through the condenser lens 430R and the incident side polarizing plate 410R, and enters the image forming area of the liquid crystal device 400R for red light. The condenser lens 430R is provided to convert each partial light beam from the superimposing lens 150 into a light beam substantially parallel to each principal ray. The other condenser lenses 430G and 430B are configured in the same manner as the condenser lens 430R.

  Of the green light component light and blue light component light that have passed through the dichroic mirror 210, the green light component light is reflected by the dichroic mirror 220, passes through the condenser lens 300G and the incident-side polarizing plate 410G, and is a liquid crystal for green light. The light enters the image forming area of the apparatus 400G. On the other hand, the blue light component light passes through the dichroic mirror 220 and enters the relay optical system 300.

  The relay optical system 300 includes an incident side lens 310, an incident side reflection mirror 320, a relay lens 330, and a reflection prism 340, and guides blue light component light transmitted through the dichroic mirror 220 to the liquid crystal device 400B. It has a function. The light of the blue light component incident on the relay optical system 300 passes through the incident side lens 310 and is bent by the reflection mirror 320. After the in-plane luminance distribution pattern is inverted vertically and horizontally by the relay lens 330, the condensing lens The light passes through 430B, is bent by the reflecting surface of the reflecting prism 340, passes through the incident-side polarizing plate 410B, and enters the image forming area of the blue light liquid crystal device 400B.

  The reflecting prism 340 is a triangular prism made of a light-transmitting material such as quartz glass, crystal, or sapphire. A condenser lens 430B is attached to the light incident surface of the reflecting prism 340 via an adhesive or an adhesive. On the other hand, the incident-side polarizing plate 410B is attached to the light exit surface of the reflecting prism 340 via an adhesive or an adhesive.

  The reflection prism 340 is provided with an attitude adjustment device 350 for finely adjusting the attitude (arrangement angle and the like) of the reflection prism 340.

The liquid crystal devices 400 </ b> R, 400 </ b> G, and 400 </ b> B modulate the illumination light beam according to the image information and are the illumination target of the illumination device 100.
The liquid crystal devices 400R, 400G, and 400B are a pair of transparent glass substrates in which a liquid crystal that is an electro-optical material is hermetically sealed. The polarization direction of one type of linearly polarized light emitted from the plates 410R, 410G, and 410B is modulated.

  Incident-side polarizing plates 410R and 410G are interposed between the condenser lenses 430R and 430G and the liquid crystal devices 400R and 400G, respectively. The incident-side polarizing plates 410R and 410G are attached to translucent substrates 412R and 412G made of, for example, quartz glass. Between the liquid crystal devices 400R, 400G, and 400B and the cross dichroic prism 500, exit side polarizing plates 420R, 420G, and 420B are interposed, respectively. The exit-side polarizing plates 420R, 420G, and 420B are attached to the light incident surfaces of the cross dichroic prism 500, respectively.

  The incident-side polarizing plates 410R, 410G, and 410B, the liquid crystal devices 400R, 400G, and 400B and the emission-side polarizing plates 420R, 420G, and 420B perform light modulation of incident color light.

  The cross dichroic prism 500 is an optical element that forms a color image by synthesizing optical images modulated for the respective color lights emitted from the emission-side polarizing plates 420R, 420G, and 420B. The cross dichroic prism 500 has a substantially square shape in plan view in which four right-angle prisms are bonded together, and a dielectric multilayer film is formed on a substantially X-shaped interface in which the right-angle prisms are bonded together. The dielectric multilayer film formed at one of the substantially X-shaped interfaces reflects red light, and the dielectric multilayer film formed at the other interface reflects blue light. By these dielectric multilayer films, the red light and the blue light are bent and aligned with the traveling direction of the green light, so that the three color lights are synthesized.

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

  The illumination device 100 and the color separation optical system 200 are arranged in a positional relationship such that the long side direction of the illumination device 100 and the long side direction of the color separation optical system 200 in the horizontal plane (xz plane) are substantially the same. ing. In other words, the virtual extension line of the illumination optical axis OC of the illumination apparatus 100 and the virtual extension line of the projection optical axis 600ax of the projection optical system 600 are substantially orthogonal, or the virtual extension of the illumination optical axis OC of the illumination apparatus 100. The illumination device 100 and the color separation optical system 200 are arranged so that the line and the central axis of the green light reflected by the dichroic mirror 220 of the color separation optical system 200 are substantially orthogonal to each other.

  According to the projector 1000 according to the first embodiment configured as described above, the color separation optical system 200 is directed toward the liquid crystal device 400B in the relay optical system 300 disposed on the side opposite to the side on which the illumination device 100 is disposed. As a reflection element that reflects light, a reflection prism 340 is provided instead of a reflection mirror, a condenser lens 430B is attached to the light incident surface of the reflection prism 340, and an incident-side polarizing plate 410B is attached to the light exit surface. Therefore, the distance between the liquid crystal device 400B and the reflecting prism 340 can be made shorter than the distance between the liquid crystal device and the reflecting mirror in the conventional configuration. For this reason, the space of the optical path portion of the relay optical system 300 can be reduced. As a result, the planar size of the color separation optical system 200 can be reduced, and the projector 1000 can be reduced in size.

  Further, according to the projector 1000 according to the first embodiment, since the reflecting element is provided with the reflecting prism 340 instead of the reflecting mirror, the light from the condensing lens 430B passes through the prism medium instead of in the air. The length is shortened. As a result, the telecentricity of the condenser lens 430B can be ensured while the projector 1000 is downsized.

  Further, according to the projector 1000 according to the first embodiment, since the condenser lens 430B, the reflecting prism 340, and the incident-side polarizing plate 410B are attached to each other, undesirable reflection at the interface of each member does not occur. The light transmittance can be increased.

  Further, according to the projector 1000 according to the first embodiment, since the incident-side polarizing plate 410B and the condenser lens 430B are attached to the reflecting prism 340, these three parts can be unitized. It is possible to reduce the number of parts.

  Further, according to the projector 1000 according to the first embodiment, since the reflecting prism 340 has a relatively large heat capacity, it is possible to suppress the temperature rise of the incident-side polarizing plate 410B attached to the reflecting prism 340. The heat dissipation performance can be improved.

  In the projector 1000 according to the first embodiment, the color separation optical system 200 further includes a relay optical system 300 that guides blue light of the three color lights to the illuminated area, and the reflection prism 340 includes the relay optical system 300. It is arranged in the optical path of blue light passing through. As a result, the planar size of the color separation optical system 200 can be reduced, so that the projector including the relay optical system can be downsized.

  In the projector 1000 according to the first embodiment, the illumination device 100 and the color separation optical system 200 are substantially the same in the long side direction of the illumination device 100 and the long side direction of the color separation optical system 200 in the horizontal plane (xz plane). They are arranged in such a positional relationship. In other words, the illumination device 100 is disposed on one end side in the long side direction of the optical system of the projector 1000, and the relay optical system is disposed on the other end side in the long side direction. At this time, in the projector 1000 according to the first embodiment, the length of the relay optical system 300 along the long side direction of the optical system of the projector 1000 can be made shorter than that of the conventional configuration. It is possible to shorten the length in the long side direction.

  Since the projector 1000 according to the first embodiment further includes an attitude adjustment device 350 that can adjust the attitude of the reflecting prism 340, the attitude (arrangement angle, etc.) of the reflecting prism 340 is finely adjusted to adjust the liquid crystal device 400B. It is possible to adjust the position of the light applied to the image forming area.

[Embodiment 2]
FIG. 2 is a diagram illustrating an optical system of the projector 1002 according to the second embodiment. 2, the same members as those in FIG. 1 are denoted by the same reference numerals, and detailed description thereof is omitted.

  The projector 1002 according to the second embodiment basically has a configuration similar to that of the projector 1000 according to the first embodiment, but the configuration of the color separation optical system is different from that of the projector 1000 according to the first embodiment. .

  That is, in the projector 1002 according to the second embodiment, as shown in FIG. 2, the color separation optical system 202 includes a dichroic mirror 210 that reflects red light component light and transmits other color light component light, and a dichroic mirror. The reflection prism 240 that reflects the red light reflected by 210 toward the liquid crystal device 400R and the green light component light and the blue light component light of the green light component light and the blue light component light that have passed through the dichroic mirror 210 are reflected. It includes a dichroic prism 260 having a dichroic surface 262 that transmits light, and a relay optical system 302 that guides blue light component light emitted from the dichroic prism 260 to the liquid crystal device 400B.

  The reflecting prism 240 is a triangular prism made of a translucent material such as quartz glass, quartz crystal, or sapphire. A condensing lens 430R is attached to the light incident surface of the reflecting prism 240 via an adhesive or an adhesive. On the other hand, the incident-side polarizing plate 410R is attached to the light exit surface of the reflecting prism 240 via an adhesive or an adhesive.

  The reflection prism 240 is provided with a posture adjustment device 250 for finely adjusting the posture (arrangement angle and the like) of the reflection prism 240.

  The light of the red light component reflected by the dichroic mirror 210 passes through the condenser lens 430R, is bent by the reflecting surface of the reflecting prism 240, passes through the incident-side polarizing plate 410R, and the image of the liquid crystal device 400R for red light. Incident into the formation area.

  The dichroic prism 260 is an optical element in which a dichroic surface (wavelength selection film) 262 that reflects a light beam in a predetermined wavelength region and transmits a light beam in another wavelength region is formed at the interface between two triangular prisms.

  The two triangular prisms constituting the dichroic prism 260 are made of a light-transmitting material such as quartz glass, crystal, or sapphire. A condenser lens 430G is attached to the light incident surface of the dichroic prism 262 via an adhesive or an adhesive. On the other hand, of the two light exit surfaces of the dichroic prism 260, the incident-side polarizing plate 410G is attached to the light exit surface of the green light path via an adhesive or an adhesive, so that the light exit of the blue light path is performed. The incident side lens 312 of the relay optical system 302 is attached to the surface via an adhesive or an adhesive.

  The dichroic prism 260 is provided with a posture adjusting device 270 for finely adjusting the posture (arrangement angle or the like) of the dichroic prism 260.

  Of the green and blue light components that have passed through the dichroic mirror 210, the green light component is reflected by the dichroic surface 262, passes through the incident-side polarizing plate 410G, and forms an image on the liquid crystal device 400G for green light. Incident into the area. On the other hand, the blue light component light passes through the dichroic surface 262 and enters the relay optical system 302.

  The relay optical system 302 is substantially the same as the relay optical system 300 described in the first embodiment, and thus detailed description thereof is omitted.

  As described above, the projector 1002 according to the second embodiment differs from the projector 1000 according to the first embodiment in the configuration of the color separation optical system, but is similar to the projector 1000 according to the first embodiment in the liquid crystal device 400B. A reflection prism 340 is provided instead of a reflection mirror as a reflection element that reflects light toward the light source, a condensing lens 430B is attached to the light incident surface of the reflection prism 340, and an incident-side polarizing plate 410B is attached to the light emission surface. Therefore, the distance between the liquid crystal device 400B and the reflecting prism 340 can be made shorter than the distance between the liquid crystal device and the reflecting mirror in the conventional configuration. For this reason, the space of the optical path portion of the relay optical system 300 can be reduced. As a result, the planar size of the color separation optical system 202 can be reduced, and the projector 1002 can be downsized.

The projector 1002 according to the second embodiment includes a reflecting prism 240 instead of a reflecting mirror as a reflecting element that reflects light toward the liquid crystal device 400R, and a condenser lens 430R is attached to the light incident surface of the reflecting prism 240. In addition, since the incident-side polarizing plate 410R is attached to the light exit surface, the distance between the liquid crystal device 400R and the reflecting prism 240 can be made shorter than the distance between the liquid crystal device and the reflecting mirror in the conventional configuration. For this reason, it is possible to reduce the space of the optical path portion from the dichroic mirror 210 to the liquid crystal device 400R. In addition, since the dichroic prism 260 is provided instead of the dichroic mirror 220, the condensing lens 430G is attached to the light incident surface of the dichroic prism 260, and the incident-side polarizing plate 410G is attached to the light emitting surface of green light. The distance between the liquid crystal device 400G and the dichroic prism 260 can be made shorter than the distance between the liquid crystal device and the dichroic mirror in the conventional configuration. For this reason, it is possible to reduce the space of the optical path portion from the dichroic mirror 210 to the liquid crystal device 400G.
As a result, the planar size of the color separation optical system 202 can be further reduced, and the projector 1002 can be further reduced in size.

  The projector 1002 according to the second embodiment has the same configuration as the projector 1000 according to the first embodiment except that the configuration of the color separation optical system (configuration from the dichroic mirror 210 to the liquid crystal device 400G or the liquid crystal device 400B) is different. Therefore, the projector 1000 according to the first embodiment has the corresponding effect as it is.

  The projector of the present invention has been described based on each of the above embodiments. However, the present invention is not limited to each of the above embodiments, and can be implemented in various modes without departing from the scope of the invention. For example, the following modifications are possible.

(1) In projectors 1000 and 1002 according to the above embodiments, a case where a condenser lens is attached to the light incident surface of the reflecting prism and an incident side polarizing plate is attached to the light exit surface is exemplified. As described above, the present invention is not limited to this, and the incident side polarizing plate may be attached to the light incident surface of the reflecting prism, and the condensing lens may be attached to the light exit surface.

(2) In the projectors 1000 and 1002 according to the above-described embodiments, the illumination device 100 and the color separation optical systems 200 and 202 include the long side direction of the illumination device 100 and the long sides of the color separation optical systems 200 and 202 in the horizontal plane. However, the present invention is not limited to this, and the long-side direction of the illuminating device in the horizontal plane and the color separation optical system are described. It may be arranged in a positional relationship such that the long side direction is substantially orthogonal.

(3) In the projectors 1000 and 1002 according to the above embodiments, the reflecting prism and the condensing lens are configured as separate bodies, but the present invention is not limited to this, and the reflecting prism and the condensing lens are configured. The lens may be integrally formed. In this case, it is possible to omit the attaching operation when attaching the condenser lens to the light incident surface or the light exit surface of the reflecting prism.

(4) In projectors 1000 and 1002 according to the above embodiments, the incident-side polarizing plate is directly attached to the light exit surface of the reflecting prism. However, the present invention is not limited to this, and The incident-side polarizing plate may be attached to the light exit surface with a translucent substrate interposed.

(5) In the projectors 1000 and 1002 according to the above-described embodiments, the secondary mirror is used as the reflecting means disposed in the arc tube, but the present invention is not limited to this, and the reflecting film is used as the reflecting means. It is also preferable to use. Further, in the projectors 1000 and 1002 according to each of the above embodiments, the projector in which the secondary mirror as the reflecting means is disposed in the arc tube is described as an example. However, the present invention is not limited to this. In addition, the present invention can be applied to a projector in which a secondary mirror is not provided.

(6) In the projectors 1000 and 1002 according to the above-described embodiments, the light source device including the ellipsoidal reflector is used as the light source device. However, the present invention is not limited to this, and includes the parabolic reflector. It is also preferable to use a light source device. In this case, the concave lens may not be provided.

(7) The projectors 1000 and 1002 according to the above embodiments are transmissive projectors, but the present invention is not limited to this. The present invention can also be applied to a reflection type projector. Here, “transmission type” means that an electro-optic modulation device as a light modulation means, such as a transmission type liquid crystal device, transmits light, and “reflection type” This means that an electro-optic modulation device as a light modulation means, such as a reflective liquid crystal device, is a type that reflects light. Even when the present invention is applied to a reflective projector, the same effect as that of a transmissive projector can be obtained.

(8) In the projectors 1000 and 1002 according to the above-described embodiments, the projector using the three liquid crystal devices 400R, 400G, and 400B has been described as an example. However, the present invention is not limited to this, and The present invention can also be applied to a projector using two, four, or four or more liquid crystal devices.

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

FIG. 3 shows an optical system of the projector 1000 according to the first embodiment. FIG. 6 is a diagram showing an optical system of a projector 1002 according to a second embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 100 ... Illuminating device, 110 ... Light source device, 112 ... Light emission tube, 114 ... Ellipsoidal reflector, 116 ... Secondary mirror, 118 ... Concave lens, 120 ... First lens array, 122 ... First small lens, 130 ... Second lens array 132, second small lens, 140, polarization conversion element, 150, superposition lens, 200, 202, color separation optical system, 210, 220, dichroic mirror, 230, 320, reflection mirror, 240, 340, reflection prism, 250 , 270, 350 ... posture adjustment device, 260 ... dichroic prism, 262 ... dichroic surface, 300, 302 ... relay optical system, 310, 312 ... incident side lens, 330 ... relay lens, 400R, 400G, 400B ... liquid crystal device, 410R , 410G, 410B... Incident side polarizing plate, 412R, 412G... Substrate, 42 R, 420G, 420B: exit side polarizing plate, 430R, 430G, 430B ... condensing lens, 500 ... cross dichroic prism, 600 ... projection optical system, 600ax ... projection optical axis, 1000, 1002 ... projector, OC ... illumination optical axis , SCR ... screen

Claims (4)

An illumination device that emits illumination light flux;
A color separation optical system that separates light from the illumination device into a plurality of color lights and guides the light to an illuminated area;
A plurality of liquid crystal devices that respectively modulate the plurality of color lights separated by the color separation optical system according to image information;
A color synthesis optical system for synthesizing each color light modulated by the plurality of liquid crystal devices;
A projection optical system for projecting the image light synthesized by the color synthesis optical system,
The color separation optical system includes a reflecting prism that is disposed in an optical path of at least one color light among the plurality of color lights, and reflects light from the illumination device toward the liquid crystal device,
An incident side polarizing plate is attached to one of the light incident surface and the light exit surface of the reflecting prism,
A projector characterized in that a condensing lens is attached to the other surface of the reflecting prism. The projector according to claim 1, wherein
The color separation optical system further includes a relay optical system that guides one color light of the plurality of color lights to an illuminated area,
The projector according to claim 1, wherein the reflecting prism is disposed in an optical path of colored light passing through the relay optical system. The projector according to claim 2,
The illumination device and the color separation optical system are arranged in a positional relationship such that a long side direction of the illumination device and a long side direction of the color separation optical system in a horizontal plane are substantially the same. Projector. The projector according to any one of claims 1 to 3,
A projector further comprising an attitude adjustment device capable of adjusting an attitude of the reflecting prism.

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