JP2010151885A - Projector - Google Patents

Abstract

A projector capable of achieving downsizing at low cost by incorporating an inexpensive and small relay optical system.
A relay system for extending an optical path adjusts the state of a light beam incident on a first relay lens LL1 that forms an intermediate image IM formed once while suppressing the divergence of the light beam, and a light valve 40c. Since the lens is composed of two lenses, the relay lens LL2, the number of lenses and supporting members disposed in the third optical path OP3 is reduced as compared with the conventional one, and the third optical path OP3, that is, the color separation light guide optical system 30 is reduced. It can be simple and low-cost. The projector 100 of this embodiment incorporating such a color separation light guide optical system 30 is small and low-cost.
[Selection] Figure 1

Description

  The present invention relates to a projector that modulates illumination light using a liquid crystal panel or the like and projects the modulated image light.

As a conventional general projector, a light source that generates substantially white light, an illumination optical system that uniformizes and converts the light from the light source, and light that has passed through the illumination optical system are separated into green, blue, and red light. Color separation light guide optical system to be introduced into the three-color optical path, three liquid crystal light valves respectively illuminated by the three-color illumination light, and a cross dichroic prism for synthesizing images from these three liquid crystal light valves. Some have a projection lens that projects a later magnified image. In such a projector, for example, the optical path lengths of two colors are made equal, the remaining one color optical path is lengthened, and the relative optical path length is compensated to compensate for the relay optical system on the long optical path of one color. (See, for example, Patent Document 1). The relay optical system on the long optical path is composed of a first lens, a second lens, and a field lens in order from the light source side, and the first lens is disposed in the vicinity of the intermediate image once formed in the middle of the long optical path, The field lens is disposed in the vicinity of the liquid crystal light valve, and the second lens is disposed at an intermediate position between the first lens and the field lens.
JP 2005-266765 A

  In recent years, there has been an increasing demand for miniaturization and cost reduction in projectors for specific applications. However, there is a limit to space saving due to the relay optical system as a bottleneck, which is sufficient for demands for miniaturization and cost reduction of projectors. There is a situation where it is not possible to respond to.

  Accordingly, an object of the present invention is to provide a projector that can achieve miniaturization at low cost by incorporating an inexpensive and small relay optical system.

  In order to solve the above-described problems, a projector according to the present invention separates a light source that emits light source light, an illumination optical system that equalizes the light source light, and illumination light emitted from the illumination optical system into light beams of respective colors. A color separation light guide optical system, a light modulation device for each color illuminated by a light beam of each color light separated by the color separation light guide optical system, and an image light of each color emitted from the light modulation device for each color And a projection optical system that projects image light that has passed through the synthesis optical system. Here, the color separation light guide optical system has a relay system for extending the optical path in the optical path of at least one color constituting a part of the optical path of each color, and the relay system converts the intermediate image once formed into the luminous flux. The first relay lens that forms an image while suppressing divergence and the second relay lens that adjusts the state of the light beam incident on the light modulation device on the corresponding optical path.

  In the projector, the relay system for extending the optical path includes two lenses, that is, a first relay lens that forms an intermediate image once formed while suppressing the divergence of the light beam, and the state of the light beam incident on the light modulation device. Since the second relay lens to be adjusted is used, the number of lenses arranged in the relay optical path and its supporting members are reduced as compared with the conventional one, and the relay system can be simplified and reduced in cost. A projector incorporating such a relay system is small and low-cost.

  According to a specific aspect or aspect of the present invention, in the projector, the relay system forms an intermediate image once formed on the corresponding light modulation device at an equal magnification. In this case, increase / decrease in illuminance by the relay system can be suppressed, and the illumination light quantity of the light modulation device arranged in the optical path with the relay system, and the illumination light quantity of the light modulation device arranged in the optical path without the other relay system Can keep the balance.

  According to another aspect of the present invention, in the first relay lens, at least one of the entrance surface and the exit surface is an aspheric surface. In this case, by making the first relay lens an aspheric lens, the intermediate image can be re-imaged on the light modulation device with low aberration, and the light modulation device can be illuminated more uniformly.

  According to still another aspect of the present invention, the color separation light guide optical system includes a first color separation mirror that separates a light beam emitted from the illumination optical system into first color light and other color light, and other color light. A second color separation mirror that separates the second color light and the third color light, and a first fold that leads to the first color light modulation device by reflecting the first color light that has passed through the first color separation mirror and bending the optical path. A curved mirror, and second and third folding mirrors that guide the third color light to the light modulation device by reflecting the third color light that has passed through the second separation mirror and bending the optical path. Further, the first relay lens is provided between the second folding mirror and the third folding mirror. Note that the second color light separated by the second separation mirror is directly guided to the light modulation device for the second color light. In this case, the first relay lens can be arranged relatively downstream of the optical path.

  According to still another aspect of the present invention, the color separation light guide optical system includes a first color separation mirror that separates a light beam emitted from the illumination optical system into first color light and other color light, and other color light. A second color separation mirror that separates the second color light and the third color light, and a first fold that leads to the first color light modulation device by reflecting the first color light that has passed through the first color separation mirror and bending the optical path. A curved mirror, and second and third folding mirrors that guide the third color light to the light modulation device by reflecting the third color light that has passed through the second separation mirror and bending the optical path. Further, the first relay lens is provided between the second color separation mirror and the second folding mirror. Note that the second color light separated by the second separation mirror is directly guided to the light modulation device for the second color light. In this case, the first relay lens can be arranged relatively upstream of the optical path.

  According to still another aspect of the present invention, the second relay lens is provided between the third bending mirror and the light modulation device for the third color light. In this case, the second relay lens is disposed immediately before the light modulator for the third color light, and the angular state of the light beam incident on the light modulator can be easily adjusted.

  According to still another aspect of the present invention, the distance between the second color separation mirror and the second folding mirror is shorter than the distance between the second folding mirror and the third folding mirror. In this case, the optical path of the third color light in which the relay optical path, that is, the relay system is arranged can be made relatively short. Furthermore, when the first relay lens is disposed between the second and third folding mirrors, the first relay lens can be easily disposed closer to the second color separation mirror, so that the second color separation is performed. The effect of suppressing the divergence of the light beam from the intermediate image once formed downstream of the optical path of the mirror by the first relay lens can be enhanced.

  According to still another aspect of the present invention, the color separation light guide optical system has a relay system for extending an optical path in each of two color optical paths constituting a part of the optical path of each color. Furthermore, each relay system adjusts the state of the light beam incident on the light modulation device on the corresponding optical path and the first relay lens that forms an intermediate image once formed on the corresponding optical path while suppressing the divergence of the light beam. And a second relay lens. In this case, a projector having a two-color relay system can be made relatively small and low cost.

[First Embodiment]
FIG. 1 is a conceptual diagram illustrating the configuration of the optical system of the projector according to the first embodiment of the invention.

  The projector 100 is an optical device for modulating a light beam emitted from a light source according to image information to form a color optical image, and enlarging and projecting the optical image on a screen. The illumination optical system 20, the color separation light guide optical system 30, the light modulation unit 40, the cross dichroic prism 50, and the projection lens 60 are configured. Here, the light source lamp unit 10 and the illumination optical system 20 constitute an illumination device that generates illumination light to be incident on the color separation light guide optical system 30 and the like.

  The light source lamp unit 10 is a light source for collecting and emitting light beams emitted from the lamp body 11 to the surroundings and illuminating the light modulation unit 40 via the illumination optical system 20 and the like. The light source lamp unit 10 reflects a lamp main body 11 that is an arc tube, a spherical secondary mirror 12 that reflects light source light emitted forward from the lamp main body 11, and light source light emitted rearward from the lamp main body 11. An ellipsoidal primary mirror 13 and a collimating concave lens 14 are provided. In the light source lamp unit 10, the substantially white light source light emitted from the lamp body 11 is incident on the primary mirror 13 via the secondary mirror 12 or directly and reflected to the front side, and is collimated by the concave lens 14. In this state, the light is emitted to the illumination optical system 20 side. In addition, although the high-pressure mercury lamp is normally used for the lamp body 11 described above in that high-intensity light can be emitted over the wavelength of each color, the lamp that can be incorporated in the light source lamp unit 10 is Various light-emitting lamps other than the high-pressure mercury lamp can be used. For example, a solid-state light-emitting element such as an LED can be used. The primary mirror 13 is not limited to an elliptical surface, and various reflectors having a reflecting surface shape such as a paraboloid can be used. When the parabolic main mirror 13 is used, a parallel light beam can be emitted from the light source lamp unit 10 without providing the concave lens 14 or the like after the main mirror 13.

  The illumination optical system 20 supplies the illumination light with uniform illuminance to the light modulation unit 40. This illumination optical system 20 superimposes the first and second lens arrays 23a and 23b that divide the light beam emitted from the light source lamp unit 10 into an appropriate state and a plurality of light beams that have passed through both lens arrays 23a and 23b. A lens 25 and a polarization conversion device 24 that aligns the polarization direction of the light beam incident on the superimposing lens 25 are provided. Among these, the luminous flux emitted from the concave lens 14 of the light source lamp unit 10 is divided into a plurality of partial luminous fluxes by the element lens 27a constituting the first lens array 23a. In addition, each partial light beam from the first lens array 23a is emitted at an appropriate divergence angle by the element lens 27b constituting the second lens array 23b. The superimposing lens 25 appropriately converges the partial light beam emitted from the second lens array 23b and passing through the polarization conversion device 24 as a whole. As a result, it is possible to make the illumination light uniform so as to superimpose the illumination light in the illuminated areas of the light valves 40a, 40b, and 40c at the subsequent stage of the superimposing lens 25, that is, the display areas. The polarization conversion device 24 is formed by an array of optical elements having a set of elements such as a PBS (polarization beam splitter), a mirror, a phase difference plate, etc., and polarization of each partial light beam divided by the first lens array 23a. It has the role of aligning the direction with linearly polarized light in one direction. By using such a polarization conversion device 24, the utilization factor of the light source light used in the light modulation unit 40 can be improved.

  The color separation light guide optical system 30 includes first and second color separation mirrors 31a and 31b, first to third bending mirrors 32b, 32c, and 32d, field lenses 33a and 33b, and a first relay lens LL1. And a second relay lens LL2. The color separation light guide optical system 30 separates the illumination light emitted from the illumination optical system 20 into three colors of blue (B), green (G), and red (R), and separates each color light in the subsequent stage. Guide to light valves 40a, 40b, 40c. More specifically, first, the first color separation mirror 31a is formed of a dichroic mirror, reflects B color light, which is an example of first color light among the three colors of RGB, and emits other color light, that is, G color light and R color light. Permeate. The second color separation mirror 31b is formed of a dichroic mirror, reflects G color light, which is an example of second color light, and transmits R color light, which is an example of third color light, of the two colors of GR. The color separation light guide optical system 30 is a system optical axis that is two-dimensionally arranged along the XZ plane in order to separate the B color light, the G color light, and the R color light into the optical paths OP1, OP2, and OP3 for each color. The optical system has OA.

  In the color separation light guide optical system 30, the B color light separated by reflection by the first color separation mirror 31a enters the field lens 33a for adjusting the incident angle through the first bending mirror 32b. Further, the G color light that is transmitted through the first color separation mirror 31a and separated by reflection by the second color separation mirror 31b is incident on the field lens 33b for adjusting the incident angle. Further, the R color light separated by passing through the second color separation mirror 31b passes through the first relay lens LL1 for image formation and the second and third bending mirrors 32c and 32d for bending the optical path, and the incident angle. The light enters the second relay lens LL2 for adjustment. Here, the first and second relay lenses LL1 and LL2 are disposed on the third optical path OP3 that is longer than the others, and constitute a relay system for extending the optical path. The first relay lens LL1 is a convex lens having positive relatively strong power, and the second relay lens LL2 is a convex lens having positive relatively weak power.

  In the case of the present embodiment, the first relay lens LL1 is located between the second folding mirror 32c and the third folding mirror 32d on the third optical path OP3 for R-colored light, and both the folding mirrors 32c, It is arranged at a substantially middle position of 32d. The first relay lens LL1 is a liquid crystal panel of the light modulation unit 40 while suppressing the divergence of the light beam from the intermediate image IM that is once superimposed on the third optical path OP3 by the superimposing lens 25 of the illumination optical system 20. It has the role of re-imaging as a substantially equal magnification illumination image on 41c. The position where the intermediate image IM is formed is a conjugate position with the liquid crystal panel 41a on the first optical path OP1 and the liquid crystal panel 41b on the second optical path OP2.

  In the present embodiment, the distance a between the second color separation mirror 31b and the second folding mirror 32c is equal to the distance a between the first color separation mirror 31a and the second color separation mirror 31b. However, it is shorter than the distance b between the second folding mirror 31c and the third folding mirror 32d. As a result, the third optical path OP3 that is a relay optical path can be made relatively short, and the color separation light guide optical system 30 can be arranged in a space-saving manner. In this example, due to the distance a being shorter than the distance b, the intermediate image IM once formed by the illumination optical system 20 is disposed downstream of the center of the second folding mirror 32c on the optical path. .

  The first surface S1 that is the incident surface of the first relay lens LL1 is an aspheric surface, and the second surface S2 that is the exit surface of the second relay lens LL2 is a spherical surface. By using the first relay lens LL1 as an aspheric lens in this manner, the intermediate image IM can be formed on the liquid crystal panel 41c with low aberration, and the liquid crystal panel 41c can be illuminated more uniformly.

  In the light modulation unit 40, each light valve 40a, 40b, 40c individually modulates the spatial intensity distribution of the incident illumination light as a non-light-emitting light modulation device. The light valves 40a, 40b, and 40c include three liquid crystal panels 41a, 41b, and 41c that are illuminated corresponding to the respective color lights emitted from the color separation light guide optical system 30, and the liquid crystal panels 41a, 41b, and 41c. Three incident side polarizing plates 42a, 42b, and 42c arranged on the incident side, respectively, and three emission side polarizing plates 43a, 43b, and 43c arranged on the emission side of the liquid crystal panels 41a, 41b, and 41c, respectively. .

  In the light modulator 40 described above, the B-color light beam reflected by the first color separation mirror 31a of the color separation light guide optical system 30 and guided to the first optical path OP1 is transmitted through the field lens 33a. The light enters the light bulb 40a and illuminates the display area on the liquid crystal panel 41a constituting the light valve 40a. The G light beam transmitted through the first color separation mirror 31a of the color separation light guide optical system 30, reflected by the second color separation mirror 31b, and guided to the second optical path OP2 serves as a light modulation device via the field lens 33b. The light enters the light valve 40b and illuminates the display area on the liquid crystal panel 41b constituting the light valve 40b. The R-color light beam transmitted through both the first and second color separation mirrors 31a and 31b and guided to the third optical path OP3 is a light that is a light modulation device via the first and second relay lenses LL1 and LL2. The light enters the bulb 40c and illuminates the display area on the liquid crystal panel 41c constituting the light bulb 40c. Each of the liquid crystal panels 41a, 41b, and 41c modulates the spatial distribution of the polarization direction of the incident illumination light, and the three color illumination light beams incident on the respective liquid crystal panels 41a, 41b, and 41c change the polarization state in units of pixels. Adjusted. At this time, the polarization direction of the illumination light incident on each liquid crystal panel 41a, 41b, 41c is adjusted by the incident side polarizing plates 42a, 42b, 42c, and each liquid crystal panel is formed by the emission side polarizing plates 43a, 43b, 43c. Modulated light having a predetermined polarization direction is extracted from the modulated light emitted from 41a, 41b, and 41c. As described above, each light valve 40a, 40b, 40c forms modulated light, that is, image light of each color corresponding thereto.

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

  The projection lens 60 embodies a projection optical system, and enlarges the image light by the combined light formed through the cross dichroic prism 50 at a desired magnification to form a color image on a screen (not shown). Project.

  In the projector 100 of the present embodiment described above, the relay systems LL1 and LL1 for extending the optical path are formed on the first relay lens LL1 that forms the intermediate image IM once formed while suppressing the divergence of the light beam and the light valve 40c. Since it is composed of two lenses, the second relay lens LL2 that adjusts the state of the incident light beam, the number of lenses arranged in the third optical path OP3 and its supporting members are reduced as compared with the prior art, and the third optical path. The OP3, that is, the color separation light guide optical system 30 can be made simple and low cost. The projector 100 of this embodiment incorporating such a color separation light guide optical system 30 is small and low-cost.

[Second Embodiment]
Hereinafter, a projector according to a second embodiment of the invention will be described. FIG. 2 is a conceptual diagram illustrating the optical system of the projector according to the second embodiment. The projector 200 according to the second embodiment is obtained by changing the projector 100 according to the first embodiment with respect to the arrangement of the first relay lens LL1, and the parts not particularly described are the same as those in the first embodiment. .

  As shown in FIG. 2, in the projector 200 of the present embodiment, the first relay lens LL1 for re-imaging the intermediate image IM is between the second folding mirror 32c and the third folding mirror 32d. Thus, it is arranged in the vicinity of the second folding mirror 32c. That is, since the first relay lens LL1 is arranged close to the intermediate image IM, the effect of suppressing the divergence of the light beam from the intermediate image IM by the first relay lens LL1 can be relatively enhanced. Note that the power of the first relay lens LL1 in FIG. 2 is stronger than the power of the first relay lens LL1 in FIG.

[Third Embodiment]
Hereinafter, a projector according to a third embodiment of the invention will be described. FIG. 3 is a conceptual diagram illustrating the optical system of the projector according to the third embodiment. The projector 300 according to the third embodiment is obtained by partially changing the projector 100 according to the first embodiment with respect to the color separation light guide optical system 30, and the parts that are not particularly described are the same as those in the first embodiment. And

  As shown in FIG. 3, in the case of the projector 300 of this embodiment, in the color separation light guide optical system 30, the distance a1 between the second color separation mirror 31b and the second folding mirror 32c is the first color separation. It is longer than the distance a between the mirror 31a and the second color separation mirror 31b, and longer than the distance b1 between the second folding mirror 32c and the third folding mirror 32d. As a result, the intermediate image IM once formed by the illumination optical system 20 is formed on the upstream side of the optical path from the center of the second bending mirror 32c. Correspondingly, the first relay lens LL1 for re-imaging the intermediate image IM is between the second color separation mirror 31b and the second folding mirror 32c and close to the second folding mirror 32c. Arranged. In this case, since the first relay lens LL1 is arranged close to the intermediate image IM, the effect of suppressing the divergence of the light beam from the intermediate image IM by the first relay lens LL1 can be relatively enhanced.

[Fourth Embodiment]
Hereinafter, a projector according to a fourth embodiment of the invention will be described. FIG. 4 is a conceptual diagram illustrating the optical system of the projector according to the fourth embodiment. The projector 400 according to the fourth embodiment is obtained by partially changing the projector 300 according to the third embodiment with respect to the color separation / light guiding optical system 30, and parts that are not particularly described are the same as those according to the third embodiment. And

  As shown in FIG. 4, in the case of the projector 400 of this embodiment, in the color separation light guide optical system 30, the distance a between the second color separation mirror 31b and the second folding mirror 32c is the first color separation. It is equal to the distance a between the mirror 31a and the second color separation mirror 31b, and is also equal to the distance a between the second folding mirror 31c and the third folding mirror 32d. As a result, the intermediate image IM once formed by the illumination optical system 20 is formed on the upstream side of the optical path from the center of the second bending mirror 32c. The first relay lens LL1 for re-imaging the intermediate image IM is disposed between the second folding mirror 32c and the third folding mirror 32d.

[Fifth Embodiment]
Hereinafter, a projector according to a fifth embodiment of the invention will be described. FIG. 5 is a conceptual diagram illustrating an optical system of the projector according to the fifth embodiment. Note that a projector 500 according to the fifth embodiment is obtained by changing the projector 100 according to the first embodiment with respect to the color separation light guide optical system 30, and parts not specifically described are the same as those in the first embodiment. .

  In the projector 500 of the fifth embodiment, the color separation light guide optical system 530 includes a cross dichroic mirror 531, fourth folding mirrors 532e and 532f, fifth folding mirrors 532g and 532h, and a first relay lens. LL1, LL1, second relay lenses LL2, LL2, and a field lens 33b. In the color separation light guide optical system 530, the substantially white light source light from the illumination optical system 20 enters the cross dichroic mirror 531. The B-color light reflected by one of the first dichroic mirror units 531a constituting the cross dichroic mirror 531 passes along the first optical path OP1, and the fourth bending mirror 532e, the first relay lens LL1, and the fifth bending light. The light passes through the mirror 532g and the second relay lens LL2 sequentially and enters the light valve 40a. The G-color light traveling straight through the cross dichroic mirror 531 passes through the field lens 33b along the second optical path OP2 and enters the light valve 40b. The R-color light reflected by the other second dichroic mirror 531b constituting the cross dichroic mirror 531 follows the third optical path OP3, the fourth folding mirror 532f, the first relay lens LL1, and the fifth folding. The light passes through the mirror 532h and the second relay lens LL2 sequentially and enters the light valve 40c.

  In the projector 500 of the fifth embodiment described above, each relay system for extending the optical path forms the first relay lenses LL1 and LL1 that form the intermediate image IM once formed while suppressing the divergence of the light beam, and the light valve 40a. , 40c, and the second relay lenses LL2 and LL2 for adjusting the state of the light beam incident thereon, the first and third optical paths OP1 and OP3, that is, the color separation light guide optical system 530 can be simplified. It can be made low-cost. The projector 500 according to this embodiment in which such a color separation light guide optical system 530 is incorporated is small and low-cost.

  In the projector 500 according to the fifth embodiment, the first relay lens LL1 is disposed between the fourth bending mirrors 532e and 532f and the fifth bending mirrors 532g and 532h, but the cross dichroic mirror 531 A configuration in which the first relay lenses LL1 and LL1 are disposed between the fourth bending mirrors 532e and 532f is also possible. At this time, the distance b between the fourth bent mirrors 532e and 532f and the fifth bent mirrors 532g and 532h is limited only to be larger than the distance a between the cross dichroic mirror 531 and the fourth bent mirrors 532e and 532f. Instead, both the distances a and b can be made equal, or the distance b can be made smaller than the distance a.

  Although the present invention has been described based on the above embodiments, the present invention is not limited to the above-described embodiments, and can be implemented in various modes without departing from the gist thereof. Such modifications are also possible.

  That is, in the projectors 100, 200, 300, 400, and 500 according to the above-described embodiments, the illumination optical system 20 includes the first and second lens arrays 23a and 23b, the polarization conversion device 24, and the superimposing lens 25. This can be omitted for 23a, 23b, or it can be replaced by a rod integrator.

  In the projectors 100, 200, 300, and 400 according to the above-described embodiments, B-color light and G-color light are guided to the short first and optical paths OP1 and OP2, respectively, and R-color light is guided to the long third optical path OP3. The combination can be appropriately changed depending on the application. For example, it may be configured such that R color light is guided to the short first optical path OP1, G color light is guided to the short second optical path OP2, and B color light is guided to the long third optical path OP3.

  In the projectors 100, 200, 300, 400, and 500 according to the above-described embodiments, the second relay lens LL2 is disposed immediately before the light valve 40c and the like. However, the second relay lens LL2 is disposed at the third folding mirror 32d. Alternatively, it can be disposed in the vicinity of the fifth folding mirrors 532g and 532h and upstream of the third folding mirror 32d and the fifth folding mirrors 532g and 532h.

  Further, the present invention can be applied to a front projection type projector that projects from the side that observes the projected image, and a rear projection type projector that projects from the side opposite to the side that observes the projected image.

  In the projectors 100, 200, 300, 400, and 500 according to the above-described embodiments, the cross dichroic prism 50 is used for the separation and synthesis of BGR, but a cross dichroic mirror may be used.

It is a conceptual diagram explaining the structure of the projector which concerns on 1st Embodiment of this invention. It is a conceptual diagram explaining the structure of the projector which concerns on 2nd Embodiment. It is a conceptual diagram explaining the structure of the projector which concerns on 3rd Embodiment. It is a conceptual diagram explaining the structure of the projector which concerns on 4th Embodiment. It is a conceptual diagram explaining the structure of the projector which concerns on 5th Embodiment.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 ... Light source lamp unit, 11 ... Lamp main body, 20 ... Illumination optical system, 23a, 23b ... Lens array, 24 ... Polarization conversion apparatus, 25 ... Superimposition lens, 30 ... Color separation light guide optical system, 31a ... 1st color separation Mirror, 31b ... 2nd color separation mirror, 32b ... 1st bending mirror, 32c ... 2nd bending mirror, 32d ... 3rd bending mirror, 33a, 33b ... Field lens, 40 ... Light modulation part, 40a, 40b , 40c ... light valve, 41a, 41b, 41c ... liquid crystal panel, 42a, 42b, 42c ... incident side polarizing plate, 43a, 43b, 43c ... exit side polarizing plate, 50 ... cross dichroic prism, 60 ... projection lens, 100, 200, 300, 400, 500 ... projector, IM ... intermediate image, LL1 ... first relay lens, LL2 ... first 2 relay lenses, OA ... system optical axis, OP1 ... first optical path, OP2 ... second optical path, OP3 ... third optical path

Claims (8)

A light source that emits light source light;
An illumination optical system for making the light source light uniform;
A color separation light guide optical system for separating the illumination light emitted from the illumination optical system into light beams of respective colors;
A light modulation device for each color that is illuminated by a light beam of each color light separated by the color separation light guide optical system;
A combining optical system that combines the image light of each color emitted from the light modulation device for each color;
A projection optical system for projecting image light that has passed through the synthetic optical system;
With
The color separation light guide optical system has a relay system for extending an optical path in an optical path of at least one color constituting a part of an optical path of each color,
The relay system includes a first relay lens that forms an intermediate image once formed while suppressing divergence of the light beam, and a second relay lens that adjusts the state of the light beam incident on the light modulation device on the corresponding optical path. Constructed projector.   The projector according to claim 1, wherein the relay system forms an intermediate image once formed on the corresponding light modulation device at an equal magnification.   The projector according to claim 1, wherein the first relay lens has an aspheric surface at least one of an incident surface and an exit surface. The color separation light guide optical system includes a first color separation mirror that separates a light beam emitted from the illumination optical system into a first color light and another color light, and the other color light as a second color light and a third color light. A second color separation mirror that separates the first color light, a first folding mirror that reflects the first color light that has passed through the first color separation mirror and bends an optical path to guide the first color light to a light modulation device; A second and a third bent mirror for reflecting the third color light that has passed through the two separation mirrors and bending the optical path to lead to the light modulator for the third color light;
The first relay lens is provided between the second folding mirror and the third folding mirror;
The projector as described in any one of Claim 1- Claim 3. The color separation light guide optical system includes a first color separation mirror that separates a light beam emitted from the illumination optical system into a first color light and another color light, and the other color light as a second color light and a third color light. A second color separation mirror that separates the first color light, a first folding mirror that reflects the first color light that has passed through the first color separation mirror and bends an optical path to guide the first color light to a light modulation device; A second and a third bent mirror for reflecting the third color light that has passed through the two separation mirrors and bending the optical path to lead to the light modulator for the third color light;
The first relay lens is provided between the second color separation mirror and the second folding mirror;
The projector as described in any one of Claim 1- Claim 3.   6. The projector according to claim 4, wherein the second relay lens is provided between the third bending mirror and the light modulator for the third color light. 7.   The distance between the second color separation mirror and the second folding mirror is shorter than the distance between the second folding mirror and the third folding mirror. The projector according to any one of the above. The color separation light guide optical system has a relay system for extending an optical path in two color optical paths constituting a part of each color optical path,
Each relay system adjusts the state of the first relay lens that forms an intermediate image once formed on the corresponding optical path while suppressing the divergence of the light flux and the state of the light flux incident on the light modulator on the corresponding optical path. The projector according to any one of claims 1 to 3, comprising two relay lenses.

Images