JP2004212529A - Illumination optical system and projection display device using same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain an illumination optical system equipped with an outer periphery auxiliary light source part to emit a beam so as to compensate a low-density part on the outer periphery part of the beam from a main light source part equipped with a reflector with the beam and a means to uniformize the light quantity distribution of each beam, made compact and realizing bright and uniform illumination having high illumination efficiency, and to obtain a projection display device using the optical system. <P>SOLUTION: The illumination optical system is equipped with the main light source part 1 equipped with the parabolic mirror reflector 12, periphery and center auxiliary light source parts 8 and 2 to compensate the low-density part on the outer periphery part and the center part of the beam from the light source part 1 with the beam, a first integrator part 4, a second integrator part (not shown) and third integrator part 5 to uniformize the light quantity distribution of the beams from the respective light source parts 1, 8 and 2. The beam from the outer periphery auxiliary light source part 8 consisting of laser beam sources 52a and 52b is introduced to positions nearly rotationally symmetric with respect to the optical axis of the reflector, and a member on its optical path is nearly the same as a member on the optical path of the beam from the center auxiliary light source part 2 and is arranged in parallel with it. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an illumination optical system that illuminates an object to be illuminated using a light source unit having a light emitting body and a reflector, and in particular, modulates an illumination light beam with a light valve, and forms an image on a screen with the projection light beam. The present invention relates to an illumination optical system suitable for a projection display device that performs enlarged projection, and a projection display device using the same.
[0002]
[Prior art]
2. Description of the Related Art In recent years, in a projection display device, a bright projection display device has been developed so that it can be used without problem even in a bright place. As an element that greatly contributes to improvement in brightness, along with a light valve, an illumination optical system is being developed. For example, there is a configuration in which the amount of light is increased by an illumination optical system including a plurality of light source units as described in Patent Literature 1.
[0003]
[Patent Document 1]
JP-A-2001-21996
[0004]
[Problems to be solved by the invention]
There have been proposed many techniques for improving the brightness by the configuration of the illumination optical system using many bright light source units. Above all, a light source unit having a reflector is often used as a light source unit which is advantageous in cost and is bright. However, an illumination optical system using a large number of light sources of the same degree needs to be provided with these light sources and means for synthesizing light beams from these light sources.
[0005]
If the highest priority is to increase the total amount of light emitted from the illumination optical system as much as possible, such a configuration is also effective, but on the other hand, a light source unit equipped with a conventional reflector has been improved. There is also a demand that there is little change in the configuration, that the size of the illumination optical system be compact, and that the brightness be improved as much as possible. If a light source unit having a conventional reflector and a configuration of an illumination optical system and a projection display device corresponding to the light source unit can be used with few changes, it is advantageous in terms of cost.
[0006]
The present invention has been made in view of such circumstances, and focuses on a light amount distribution of a light beam emitted from a light source unit including a light source and a reflector, and makes a large design change to a conventional light source unit of this type. It is an object of the present invention to provide an illumination optical system which is compact, has high illumination efficiency, can perform bright and uniform illumination, and a projection display apparatus using the same.
[0007]
[Means for Solving the Problems]
An illumination optical system according to the present invention includes a main light source unit including a light emitting body and a reflector for reflecting light emitted from the light emitting body toward an object to be illuminated, and a main light source unit for uniforming the light amount of a light beam from the main light source unit. An integrator section, an outer peripheral auxiliary light source section that emits a light beam so as to supplement a light flux in a low-density portion of an outer peripheral portion of the light beam emitted from the main light source section, and a uniform light amount of the light beam from the outer peripheral auxiliary light source section. And an outer peripheral auxiliary integrator section to be provided.
[0008]
Here, the terms "main integrator section" and "outer periphery auxiliary integrator section" are functionally expressed, and the actual form is not limited to the case where they are separated from each other. Is included. Further, the case where these two integrator units are shared is also included.
[0009]
An illumination optical system according to the present invention includes a main light source unit including a light emitting body and a reflector for reflecting light emitted from the light emitting body toward an object to be illuminated, and a main light source unit for uniforming the light amount of a light beam from the main light source unit. An integrator portion, and a peripheral auxiliary light source portion that emits a light beam so as to supplement the light beam in a light flux low-density portion of an outer peripheral portion of the light beam emitted from the main light source portion, and the light beam emitted from the outer peripheral light source portion is The light quantity distribution in the emitted light is substantially uniform, and a means for making the light quantity of the light flux from the outer peripheral auxiliary light source unit uniform is omitted.
[0010]
Further, it is preferable that a central auxiliary light source unit that emits a light beam so as to supplement the light beam is provided in a low-density portion near the center of the light beam emitted from the main light source unit.
[0011]
It is preferable that the outer peripheral auxiliary light source unit includes a plurality of light sources. In addition, it is more preferable that the outer peripheral auxiliary light source unit includes a plurality of light sources that emit light beams at positions in the low-density light portion of the outer peripheral portion that are substantially rotationally symmetric with respect to the optical axis of the reflector. .
[0012]
Further, the pupil plane of the illumination optical system and the irradiation surface of the light beam emitted from the main light source unit are configured to partially overlap each other in a cross section orthogonal to the optical axis at the pupil position of the illumination optical system, and It is preferable that the peripheral auxiliary light source unit that emits a light beam so as to supplement a light beam in a portion where the pupil surface protrudes from the irradiation surface in a portion where the pupil surface and the irradiation surface do not overlap with each other is preferable. In this case, the reflector may be a square reflector that emits a light beam having a substantially rectangular shape in a cross section orthogonal to the optical axis.
[0013]
A projection display device according to the present invention includes any one of the above-described illumination optical systems, and illuminates at least one light valve that performs light modulation of an illumination light beam based on predetermined image information with a light beam from the illumination optical system. A light beam carrying image information from the light valve is projected via a projection optical system.
[0014]
BEST MODE FOR CARRYING OUT THE INVENTION
An embodiment of the present invention will be described using an illumination optical system according to a first embodiment of the present invention as an example.
[0015]
<Example 1>
FIG. 1A is a cross-sectional view of the illumination optical system according to the present embodiment, and FIG. 1B is a diagram of the illumination optical system as viewed from the side of an object to be illuminated (the direction of arrow A). FIG. 1A is a cross-sectional view B). In FIG. 1 (a) and FIGS. 3 (a), 4 (a), and 6 below, each member emphasizes the cross-sectional shape thereof, and the description of a far end face is omitted. There are things that are. The illumination optical system includes a main light source unit 1, an outer peripheral auxiliary light source unit 8, a central auxiliary light source unit 2, and a first integrator unit 4 and a second integrator unit (non-integral unit) for uniforming the light quantity distribution of light beams from these light source units. ) And a third integrator unit 5.
[0016]
The main light source unit 1 has a light emitting point of the light source 11 disposed at a focal point of a reflector 12 formed of a parabolic mirror. From an opening of the reflector 12 that reflects light emitted from the light source 11 toward the illuminated body, A substantially parallel light beam is emitted. The light source 11 preferably has a small light emission distribution and high light emission efficiency. At present, the light source 11 generally comprises an arc tube such as an ultra-high pressure mercury lamp, a metal halide lamp, or a xenon lamp.
[0017]
As a light amount distribution of a light beam emitted from the main light source unit 1 in a cross section perpendicular to the optical axis, a portion having a low light intensity (hereinafter, referred to as a light flux density portion) exists in a predetermined range. FIG. 2 is a diagram for explaining the light flux low-density portion. The white light emitted from the light source 101 is reflected by the parabolic reflector 104, and is emitted from the light source unit as a light flux substantially parallel to the optical axis X of the parabolic reflector 104. As shown in the drawing, the light quantity distribution of the emitted light beam is not uniform, and there is a light flux density portion near the optical axis X and in the outer peripheral portion.
[0018]
The low-density portion of the luminous flux in the outer peripheral portion is generated in principle when light emitted from the light emitting point 108 is reflected by the parabolic reflector 104, and the amount of reflected light near the optical axis X is large. This is caused by the fact that the amount of reflected light decreases as it goes. The light flux density portion near the optical axis is generated due to a structural reason that the actual light source 101 is not a point light source but an arc tube disposed behind the reflector 104, for example. This is because light is not reflected due to the hole provided in the rear part of the reflector, or light is blocked due to the size of the luminous body itself. In order to dispose the arc tube, there is a non-mirrored area at the rear end of the reflector. If this diameter is C, at least a central part near the optical axis of the light beam emitted from the light source unit in FIG. A space through which light hardly passes exists within a range of the diameter C in a plane orthogonal to the optical axis.
[0019]
Further, the light intensity of the further outer peripheral portion of the parallel light beam emitted from the parabolic reflector 104 is not necessarily 0, and although the light intensity is weak, light is present due to leakage light or the like. In the present invention, the “light flux low-density portion” refers to a portion having low light intensity including these.
[0020]
The illumination optical system according to the present invention focuses on the light flux low-density portion existing near the outer peripheral portion and the center of the light flux emitted from such a light source portion provided with a concave mirror reflector such as the reflector 104. The outer peripheral auxiliary light source unit 8 that emits a light beam so as to supplement the light flux in the outer peripheral portion of the light beam emitted from the (main light source unit 1) so as to supplement the light beam, and supplements the light beam in the light flux dense portion near the center. And a central auxiliary light source 2 that emits a light beam.
[0021]
As shown in the cross-sectional view of FIG. 1A, the central auxiliary light source unit 2 is composed of a laser light source 31 composed of a semiconductor laser LD, and the collimator lens 35 converts the light flux from the central auxiliary light source unit 2 into a parallel light beam. And is introduced into the light flux density portion near the center of the light flux emitted from the main light source unit 1.
[0022]
As shown in FIG. 1B, the outer peripheral auxiliary light source unit 8 includes two laser light sources 52a and 52b formed of a semiconductor laser LD. Light beams from the light sources 52a and 52b are converted into parallel light beams by collimator lenses 53a and 53b, deflected by deflecting mirrors (not shown), and reflectors at light flux low-density portions on the outer peripheral portion of the light beams emitted from the main light source unit 1. They are introduced at positions that are substantially rotationally symmetric with respect to the 12 optical axes. The laser light sources 52a and 52b and the members on the optical path of the light beam from these light sources are substantially the same as the members on the optical path of the laser light source 31 and the light beam from this light source in FIG. In FIG. 1A, they are arranged so as to overlap with each other in the front direction and the depth direction of the drawing.
[0023]
The configuration in which the light flux from the auxiliary light sources 2 and 8 is supplemented to the low-density portion of the light flux emitted from the main light source 1 can increase the amount of light as a whole of the light source and improve the brightness of the illumination optical system. By installing both the outer peripheral light source unit 8 and the central auxiliary light source unit 2, the light amount can be further increased. However, the illumination light system provided with only the outer peripheral auxiliary light source unit 8 or only the central auxiliary light source unit 2 with respect to the light beam from the main light source unit provided with the reflector can increase the light quantity correspondingly.
[0024]
In addition, the outer peripheral auxiliary light source section 8 may be simply provided with the auxiliary light source section 8 on the outer peripheral portion of the light source section having a reflector generally used in the related art as the main light source section 1 with few design changes. Brightness can be improved while maintaining compactness. Further, even if a member such as a deflecting mirror is provided to supplement the light flux in the low-density portion of the outer peripheral portion, since the light intensity of the light beam from the main light source portion 1 is weak, the main light source portion The light flux from the main light source unit 1 can be efficiently used because the light flux from the main light source unit 1 is hardly blocked. Even when the light beam from the main light source unit 1 is slightly shielded, the brightness of the illumination optical system as a whole can be improved by supplementing the light amount larger than that from the outer peripheral auxiliary light source unit 8.
[0025]
The outer peripheral auxiliary light source unit 8 supplements the luminous flux to the luminous flux density portion at the outer peripheral portion of the parallel luminous flux emitted from the parabolic reflector 104, the luminous flux density portion at the outer peripheral portion of the parallel luminous flux, and both. Thus, the light beam can be emitted.
[0026]
By providing at least one light source, the outer peripheral light source unit 8 can increase the light amount of the illumination optical system. However, by providing a plurality of light sources, the brightness can be further increased. More preferably, as in the illustrated illumination optical system, it is preferable that light beams from a plurality of light sources be introduced into positions that are substantially rotationally symmetric with respect to the optical axis of the reflector 12. As a result, uniformity of the illuminance distribution can be maintained, and when used as an illumination optical system of a projection display device, even if vignetting occurs due to a lens of a subsequent projection optical system, its adverse effect is prevented, and color is prevented. Color unevenness due to the characteristics of the separation dichroic mirror can be controlled.
[0027]
Furthermore, in the case of using a rectangular reflector having a rectangular exit cross section, which is often used in recent years for the purpose of reducing the thickness of a projection display device (smaller in the height direction when the reflector optical axis is arranged horizontally). In addition, the amount of light can be increased by the outer peripheral auxiliary light source unit 8. Such a reflector has a rectangular exit cross-sectional shape having a predetermined aspect ratio, and therefore has a rectangular light flux cross section even near the pupil position of the illumination optical system. On the other hand, the pupil of the illumination optical system is circular in a cross section orthogonal to the optical axis. If the diameter of the circle is equal to or smaller than the short side of the rectangular shape, the light beam passes through the entire pupil, but in this case, the light beam passing outside the pupil is wasted. Therefore, in practice, it is acceptable that a part of the pupil through which the light beam does not pass is allowed, and more illumination light beams are configured to pass through the pupil. According to the present invention, by arranging the outer peripheral auxiliary light source section 8 so as to supplement the light flux in the portion in the pupil through which the light flux from the main light source section 1 does not pass, the brightness of the entire illumination optical system is increased. Can be improved.
[0028]
Even when a portion other than the rectangular reflector described above is present inside the pupil but does not pass the light beam from the main light source portion 1 on its outer peripheral portion, the outer peripheral auxiliary light source portion is configured to supplement the light beam in this portion. By disposing 8, the same brightness improving effect can be obtained. Such a portion is configured such that the pupil plane of the illumination optical system and the irradiation surface of the light beam emitted from the main light source section partially overlap each other in a cross section orthogonal to the optical axis at the pupil position of the illumination optical system. With respect to the illumination optical system described above, in the cross section, it can be defined that the pupil plane is a part protruding from the irradiation plane among the parts where the pupil plane does not overlap with the irradiation plane.
[0029]
Also, the central auxiliary light source section 2 can be used as a main light source section 1 with respect to a light source section having a reflector generally used in the related art, and can improve the brightness without changing the design and with compactness. The configuration in which the light flux from the central auxiliary light source section 2 is supplemented to the light flux density portion near the center of the light flux emitted from the main light source section 1 simply increases the amount of light as a whole of the light source section and contributes to the improvement of the brightness of the illumination optical system. In addition to the light intensity distribution, it is possible to enhance the light intensity in the low-density portion near the center of the light beam whose light intensity is originally desired to be the highest. Further, even if a member such as the deflecting mirror 3 is provided to supplement the light flux in the light flux low-density portion, the light intensity of the light flux from the main light source 1 is weak. The light beam from the main light source unit 1 can be used efficiently without substantially blocking the light beam.
[0030]
When the light sources of the central auxiliary light source unit 2 and the peripheral auxiliary light source unit 8 are the semiconductor lasers 31, 52a, and 52b, these light sources usually need to be used while being cooled. For this reason, it is preferable to dispose the light from the main light source unit 1 where it does not directly hit, and it is preferable that the light is introduced by a light guiding unit such as the deflection mirror 3 as necessary.
[0031]
The illumination optical system has, in addition to the above configuration, a first integrator unit 4 for uniformizing a light quantity distribution in a cross section perpendicular to the optical axis of the light beam from the main light source unit 1 and a light beam from a peripheral auxiliary light source unit 8. A second integrator unit (not shown) for uniforming the light amount distribution in a cross section perpendicular to the axis, and a third integrator unit for uniforming the light amount distribution in a cross section perpendicular to the optical axis of the light beam from the central auxiliary light source unit 2 5 is provided. In the following description, when the operation of the first to third integrators is described as “uniform light amount distribution”, the operation is performed in the above-described cross section.
[0032]
As shown in FIG. 1A, the light flux emitted from the main light source unit 1 is illuminated by a first integrator unit 4 in which a second fly eye 15 and a first fly eye 16 are arranged in this order from the main light source unit side. The light is emitted from the illumination optical system as an illumination light beam with a uniform distribution. That is, the second fly eye 15 divides the substantially parallel light beam from the main light source unit 1 into the same number of partial light beams as the number of lens cells of the second fly eye 15, and closes each of the lens cells constituting the first fly eye 16. By forming a secondary light source image of the light source 11, the light amount distribution is made uniform. As shown in FIG. 1B, the fly's eye 16 is a lens in which a plurality of lens cells 18 each composed of a minute convex lens having a rectangular contour are arranged vertically and horizontally. In FIG. 1B, a portion corresponding to the lens cell 18 is indicated by hatching. The fly's eye 15 has a shape provided with lens cells 17 corresponding to the respective lens cells 18 of the fly's eye 16. The second fly's eye 15 is arranged such that the convex surface of the lens cell 17 faces the main light source section, and the first fly's eye 16 directs the convex surface of the lens cell 18 toward the object to be illuminated.
[0033]
Concentrating lenses 37 and 38 having different shapes from the lens cells 17 and 18 are provided at the center of the fly's eyes 15 and 16 where the light beam from the central auxiliary light source 2 is incident. Although not shown, condensing lenses are provided at positions on the extension surface of the fly's eye 15 where the light flux from the outer peripheral auxiliary light source 8 is incident. Further, condensing lenses 55a and 55b are provided at positions on the extension surface of the fly eye 16 where the light flux from the outer peripheral auxiliary light source unit 8 is incident. The lens on the optical path of the light beam from the outer peripheral auxiliary light source unit 8 is a lens on the extension surface of the fly eye 15 and the condenser lens 37, and the condenser lenses 55a and 55b are lenses having the same shape as the condenser lens 38. It may be. It is advantageous in terms of cost that the fly eye 15 provided with the condenser lens 37 and the fly eye 16 provided with the condenser lens 38 have the same shape. The condensing lens provided at the position where the light beam from the outer peripheral auxiliary light source unit 8 is incident may be disposed adjacent to the first fly eye 16 or the second fly eye 15, or may be formed integrally therewith. You can also.
[0034]
The light flux emitted from the central auxiliary light source unit 2 is made uniform by the rod integrator 36 as the third integrator unit 5. The rod integrator 36 is disposed between the two fly eyes 15, 16, and a light flux from the central auxiliary light source 2 is transmitted through the second fly eye 15 by a predetermined angle due to the action of the condenser lens 37. Is incident on the rod integrator 36. Therefore, the light is reflected and emitted a plurality of times on the inner wall surface of the rod integrator 36, and the light amount distribution is made uniform.
[0035]
Further, the light flux emitted from the outer peripheral auxiliary light source unit 8 is made uniform by a rod integrator (not shown) as a second integrator unit. Although not shown, the rod integrator as the second integrator is substantially the same as the rod integrator 36 of the third integrator 5, and is parallel to the rod integrator 36 in FIG. It is arranged so as to overlap with the rod integrator 36 in the direction. The light beam from the outer peripheral auxiliary light source 8 is formed at a predetermined angle by a condensing lens provided at a position on the extension surface of the second fly eye 15 where the light from the outer peripheral auxiliary light source 8 is incident. It is incident on the integrator. Therefore, the light is reflected and emitted from the inner wall surface of each rod integrator a plurality of times, and the light amount distribution is made uniform.
[0036]
In the present embodiment and the following description, as the rod integrator, a solid rod-shaped rod prism made of glass, a hollow prism whose inner surface is mirror-finished by a reflection coating, or a rod-shaped rod prism is arranged on the light incident side. A so-called hybrid integrator, in which a hollow prism is arranged on the light beam emission side and both are combined, can be used. The light beam incident on the rod integrator is guided to the light beam emission end while being totally reflected plural times on the inner wall surface of the rod-shaped rod prism and plural times on the mirror surface of the inner wall surface of the hollow prism. The luminous flux emitted from the rod integrator is a luminous flux having a substantially uniform luminous flux density at the exit end of the rod integrator. When used as an integrator portion of a projection display device, the emission end of the rod integrator and the subsequent light valve are configured so as to form an imaging relationship (conjugate relationship) with each other via a relay lens.
[0037]
The light beams emitted from the second integrator unit and the third integrator unit 5 are refracted in a desired direction by the condenser lens 38 on the fly's eye 16 and the condenser lenses 55a and 55b on the extension surfaces thereof. The illumination optical system used in the projection display device is refracted such that the luminous flux from the outer peripheral auxiliary light source unit 8 and the central auxiliary light source unit 2 is superimposed on the subsequent light valve similarly to the luminous flux from the main light source unit 1. Preferably.
[0038]
In this embodiment, the luminous flux emitted from the outer peripheral auxiliary light source section 8 and the central auxiliary light source section 2 has a diameter of the luminous flux emitted so as to supplement the luminous flux in the low-density portion of the luminous flux emitted from the main light source section 1. Utilizing the small size, the second and third integrators for uniformizing the light quantity distribution of the light beams emitted from the auxiliary light sources 8 and 2 have a simple configuration using a rod integrator. . The position where the rod integrator is disposed is between the two fly eyes 15 and 16, and a space is effectively used to achieve a compact configuration.
[0039]
In the present invention, when the light source is such that the light amount distribution is substantially uniform in a state where the light flux emitted from the outer peripheral auxiliary light source unit 8 or the central auxiliary light source unit 2 is emitted, for example, When a simple laser light source is used, the light flux from the outer peripheral auxiliary light source unit 8 or the central auxiliary light source unit 2 does not need to be made uniform in light amount by an integrator. It can be configured.
[0040]
In addition, the central auxiliary light source unit 2 is configured to include a plurality of light sources, and the light beams from the plurality of light sources are combined so as to supplement the light flux near the center of the light beam from the main light source unit 1 to the low density portion. May be introduced into this light beam.
[0041]
Hereinafter, Examples 2 and 3 of the illumination optical system according to the present invention will be described. In each embodiment, the same components as those in the first embodiment are denoted by the same reference numerals unless otherwise specified, and detailed description of the already described matters is omitted.
[0042]
<Example 2>
FIG. 3A is a cross-sectional view of a schematic configuration of the illumination optical system according to the present embodiment. FIG. 3B is a view of the illumination optical system viewed from the side of the object to be illuminated (in the direction of the arrow A), and FIG. 3A is a cross section B of FIG. 3B. Unlike the first embodiment, this illumination optical system does not have a central auxiliary light source unit, but is a bright and compact illumination optical system by an outer peripheral auxiliary light source unit 8.
[0043]
The configuration of the main light source unit 1 of this embodiment is the same as that of the first embodiment. The first integrator unit also includes two fly eyes 15 and 16 as in the first embodiment. However, in this embodiment, since the central auxiliary light source unit is not provided, the lens cells are also provided at the center of the fly eyes 15 and 16. 17 and 18 are formed.
[0044]
The outer peripheral auxiliary light source section 8 of the present embodiment includes two light sources disposed so as to be substantially rotationally symmetric with respect to the optical axis of the reflector 12, and is provided at the focal positions of the reflectors 57a and 57b formed of parabolic mirrors. The light sources 56a and 56b are arranged respectively. The outer peripheral auxiliary light source section 8 of the illumination optical system according to the present invention is not limited to a laser light source, and may use a concave mirror reflector as in this embodiment. In this case, the outer peripheral auxiliary light source unit 8 can be configured at low cost and with a large amount of light. Since the light flux emitted from the outer peripheral auxiliary light source section 8 is substantially parallel light having a non-uniform light amount distribution, a fly-eye second integrator section 9 is provided for each light source in order to make the light amount uniform. . In order from the light source side, there are a second fly eye 58a, 58b corresponding to the outer peripheral auxiliary light source unit 8 and a first fly eye 59a, 59b corresponding to the outer peripheral auxiliary light source unit 8. Are provided at positions where the light flux from the outer peripheral auxiliary light source unit 8 is incident on both surfaces.
[0045]
FIG. 3B shows first fly eyes 59 a and 59 b corresponding to the outer peripheral auxiliary light source 8 formed on the outer peripheral portion of the first fly eye 16 on the side of the illuminated body. Each of the fly's eyes 59a and 59b is formed by arranging a plurality of lens cells 49 each composed of a minute convex lens having a rectangular outline having a size different from that of the lens cell 18. Further, as shown in FIG. 3A, the outer peripheral auxiliary light source provided with lens cells 48 corresponding to each lens cell 49 on the outer peripheral auxiliary light source unit side surface of the first fly's eyes 59a and 59b. A second fly eye 58 corresponding to the portion 8 is formed. The substantially parallel light beams from the outer peripheral auxiliary light source unit 8 are divided into respective partial light beams by the corresponding second fly eyes 58a and 58b and condensed, and further refracted in a desired direction by the corresponding first fly eyes 59a and 59b. And emitted. As the illumination optical system used in the projection display device, it is preferable that the light beam from the outer peripheral auxiliary light source unit 8 is refracted so as to be superimposed on the subsequent light valve similarly to the light beam from the main light source unit 1.
[0046]
The two fly eyes 58a, 58b, 59a, 59b of the second integrator section 9 may be integrally formed on an extension of the fly eye 16 of the first integrator section. Further, as the second integrator unit 9, not only the one in which one surface acts as the first fly eye and the other surface acts as the second fly eye as in the present embodiment, but also the first fly eye and the second fly eye. It is also possible to use a two-piece fly eye in which the fly eye is a separate member. In this case, at least one fly's eye is formed on the same member as at least one of the two fly's eyes 15 and 16 of the first integrator section, and the number of members is reduced to achieve a simple and compact configuration. be able to.
[0047]
Further, as a modification of the present embodiment, it is possible to use a reflector composed of an ellipsoidal mirror for the outer peripheral auxiliary light source section 8. In this case, a rod integrator may be used as the second integrator unit 9.
[0048]
<Example 3>
FIG. 4A is a cross-sectional view illustrating a schematic configuration of the illumination optical system according to the present embodiment. FIG. 4B is a diagram of the illumination optical system viewed from the side of the illuminated body (the direction of arrow A), and FIG. 4A is a cross section B of FIG. 4B. This illumination optical system is also a bright and compact illumination optical system by the outer peripheral auxiliary light source unit 8.
[0049]
The configuration of the main light source unit 1 of this embodiment is the same as that of the first embodiment. The two fly eyes 15 and 16 of the first integrator are the same as in the second embodiment. Further, in this embodiment, an illumination optical system including a polarization conversion optical system 6 for converting a light beam from the main light source unit 1 that generates random polarized light into linearly polarized light is provided downstream of the first integrator unit. I have. As the illumination optical system used for the projection display device, for example, when the light valve of the device is a liquid crystal panel, the light emitted from the illumination optical system is substantially parallel light whose polarization direction is aligned. In some cases, this embodiment is preferable, and this embodiment shows an example of such an embodiment.
[0050]
The polarization conversion optical system 6 aligns the polarization direction of the light beam from the main light source unit 1 emitted from the first integrator unit. The polarization conversion optical system 6 has a well-known polarization beam splitter array and a light emitting surface side of the array. The plurality of λ / 2 phase films 21 are formed of a λ / 2 phase plate arranged in a stripe shape.
[0051]
In the polarization beam splitter array, polarization separation films 19 and reflection films 20 are alternately formed therein so as to have an angle of about 45 degrees with respect to the optical axis. A light beam from the main light source unit 1 that is randomly polarized light is incident from the corresponding lens cell of the fly's eye 16 and is separated by the polarization separation film 19 into two types of polarized light, P polarized light and S polarized light having different polarization directions. One polarized light passes through the polarized light separating film 19 and is emitted from the prism surface 22. The other polarized light is reflected by the polarization separation film 19 and the adjacent reflection film 20, and finally emitted from the polarization beam splitter array at an angle substantially parallel to the light beam that has passed straight through the polarization beam splitter array, and λ / 2 When passing through the phase film 21, the light is converted into a polarization direction substantially coincident with the light beam transmitted straight through the polarization beam splitter array due to the rotation of the polarization plane, and emitted. In FIG. 4B, a hatched portion is a portion where the λ / 2 phase film 21 is provided.
[0052]
The outer peripheral auxiliary light source unit 8 of the present embodiment includes four laser light sources 52 a to 52 d (light sources 52 b and 52 d which are arranged so as to be substantially rotationally symmetric with respect to the optical axis of the reflector 12). Illustrated). Here, the light beam from the light source 52a will be described, but the same applies to the light sources 52b to 52d. The light beam from the light source 52a is incident on the rod integrator 54a as the second integrator unit 9 at a predetermined angle by the action of the condenser lens 47a. Therefore, the light is reflected and emitted a plurality of times on the inner wall surface of the rod integrator 54a, emitted in a state where the light amount distribution is uniform at the light emitting end, and refracted in a desired direction by the condenser lens 55a. It is preferable that the illumination optical system used in the projection display apparatus be refracted so that the light beam from the outer peripheral auxiliary light source unit 8 is superimposed on the subsequent light valve similarly to the light beam from the main light source unit 1.
[0053]
Although not shown, the laser light sources 52b and 52d and the members on the optical path of the light beam from these light sources are substantially the same as the laser light source 52a and the members on the optical path of the light beam from this light source in FIG. 4B, the light fluxes from the light sources 52b and 52d are incident on the condenser lenses 55b and 55d shown in FIG. 4B, respectively. It is arranged in.
[0054]
When the light sources 52a to 52d of the outer peripheral auxiliary light source unit 8 emit light beams having the same polarization direction, a polarization conversion optical system for aligning the polarization direction of light from the light source is provided. There is no need to provide such a structure, and the structure can be simplified. That is, the light source of the main light source unit 1 generates random polarized light, and this light beam is converted into linearly polarized light by the polarization conversion optical system 6 to illuminate the illuminated object. A light beam whose polarization direction is aligned so as to have a polarization direction substantially coincident with the light beam from the main light source unit 1 converted into linearly polarized light by 6 is emitted. What is necessary is just to comprise so that illumination may be performed.
[0055]
When the light sources 52a to 52d of the outer peripheral auxiliary light source unit 8 generate random polarized light, the direction of polarization of light from the light source is converted into linearly polarized light from the main light source unit 1. It is preferable to appropriately arrange a polarization conversion optical system for aligning the polarization directions so as to substantially coincide with the following.
[0056]
Also in this embodiment, the condensing lenses 47a to 47d and 55a to 55d provided at positions where the light flux from the outer peripheral auxiliary light source unit 8 is incident are adjacent to the first fly eye 16 or the second fly eye 15. They may be arranged or they may be formed integrally with them.
[0057]
The first to third embodiments have been described above as specific embodiments of the illumination optical system according to the present invention. In each embodiment, the light flux from the outer peripheral auxiliary light source unit is supplemented to the light flux low-density portion on the outer peripheral portion of the light beam emitted from the main light source unit 1, and the light amount distribution of each light beam from the main light source unit and the outer peripheral auxiliary light source unit is made uniform. Because of this configuration, it is a compact illumination optical system capable of performing bright and uniform illumination.
[0058]
By the way, as the light source used for the main light source unit of the illumination optical system according to the present invention, for example, an ultra-high pressure mercury lamp, a metal halide lamp, a xenon lamp, etc., each of which has a unique spectral distribution depending on the type. Therefore, it does not have a uniform light amount distribution in the visible light region. Regarding the projection type display device, which is the main use of the illumination optical system according to the present invention, in addition to the demand for brightness, an image with good color reproducibility is required. The dispersion of the spectral distribution of the light source may be a problem. This is because, depending on the light source, the amount of light in a wavelength range necessary for improving color reproducibility is insufficient, or the amount of light in an unnecessary wavelength range is excessive.
[0059]
For example, FIG. 5 is a diagram illustrating a spectral distribution of wavelengths in a visible region of an ultra-high pressure mercury lamp, in which the vertical axis indicates light intensity. As shown in the figure, in this light source, the red wavelength region of the three primary color lights has a smaller amount of light compared to the wavelength regions corresponding to the other color components, while it has a light intensity peak in the yellow wavelength region. When light is used, a color image with a yellow tint is formed as a whole. Therefore, conventionally, as a measure for improving the color reproducibility of the device, illumination is performed by removing light in a wavelength range around 580 nm from the light emitted from the light source. This is contrary to the demand for improvement.
[0060]
According to the illumination optical system of the present invention, there is provided an outer peripheral auxiliary light source unit that emits a light beam so as to supplement a light beam in a low-density portion of an outer peripheral portion of the light beam emitted from the main light source unit, and a light source of the outer peripheral auxiliary light source unit Out of at least one of the light sources may emit a light beam having an intensity peak in a wavelength region to be increased in the spectral distribution of the light beam emitted from the main light source unit. For example, when the luminous body of the main light source unit is the ultrahigh pressure mercury lamp, at least one of the light sources of the outer peripheral auxiliary light source unit emits a light beam having an intensity peak in a red wavelength region. is there. As this light source, for example, an inexpensive and small red semiconductor laser can be used. According to such a configuration, the light intensity in the red wavelength region increases as a whole of the illumination light flux, and light around 580 nm from an extra-high pressure mercury lamp that has conventionally adversely affected color reproducibility can be used without being excluded. Become like The amount of light that has been eliminated so far corresponds to 20% of the total amount of light of the ultra-high pressure mercury lamp, and the effect of increasing the amount of light is high.
[0061]
By configuring the luminous flux having an intensity peak in the wavelength range to be increased in the spectral distribution of the luminous flux emitted from the main light source unit to be emitted from the outer peripheral auxiliary light source unit, the amount of light from the outer peripheral auxiliary light source unit simply increases. In addition to this, the light flux from the main light source section, which had been excluded for color reproducibility, can be captured without deteriorating color reproducibility. Obtainable. Note that the intensity peak of the light beam emitted from the outer peripheral auxiliary light source is not limited to the red wavelength range, and the wavelength range can be appropriately set according to the spectral distribution of the light source of the main light source.
[0062]
Also, the light source of the central auxiliary light source may be configured to emit a light beam having an intensity peak in a wavelength range to be increased, similarly to the light source of the outer peripheral auxiliary light source. The wavelength ranges of the light sources constituting the outer peripheral light source unit and the central auxiliary light source unit do not need to be all the same, and at least one of these light sources has an intensity peak in a wavelength range different from the other light sources. May be configured to emit a light beam having the following.
[0063]
The illumination optical system of the present invention is not limited to the one described above, and various modifications can be made. For example, in the main light source section, an elliptical mirror can be used as a concave mirror reflector that reflects light from the light source and emits the light forward. When the light source is arranged at the first focal point of the reflector composed of an ellipsoidal mirror, the light flux emitted from the opening of the reflector is converged on the second focal point of the ellipsoidal mirror, for the same reason as in the case of the parabolic reflector. Thus, the outer light flux density portion and the central light flux density portion exist in a predetermined angle range around the second focal point. Therefore, by providing the outer peripheral light source unit and the central auxiliary light source unit, it is possible to obtain the same operation and effect as in the case of the parabolic reflector.
[0064]
The light source of the main light source section is not limited to the arc tube type described in the first to third embodiments, but is often used as a xenon lamp. An anode is arranged at the rear of the reflector and the light emission side of the reflector is used. From which the cathode is arranged.
[0065]
Further, the first integrator unit for making the light amount of the light beam from the main light source unit uniform is not limited to the one using two fly eyes, and for example, a rod integrator can be used.
[0066]
In addition, the outer peripheral light source unit and the central auxiliary light source unit increase the light amount of the illumination optical system, make the light amount distribution uniform, and optimize the color reproducibility (including a case where a predetermined color is desired to be strengthened or weakened). It is preferable to generate an amount of light that can achieve the intended purpose.
[0067]
Further, the shape of the lens cell of each fly eye and the shape of each lens disposed in the optical path of the light beam from each light source unit can be appropriately set. The condenser lens in the optical path of the light flux from the outer peripheral and central auxiliary light source units may have the same shape as the fly-eye lens cell.
[0068]
It should be noted that the illumination optical system according to the present invention has a conventionally-proposed and many proposed illumination optical system having a plurality of light sources simply to increase the amount of light as a total amount, and has neither the object nor the effect. Are different. A conventional illumination optical system having a plurality of light sources aims at increasing the total amount of light by arranging a plurality of light sources having a size corresponding to the main light source of the present invention. These do not have the idea of supplementing the light flux from another light source to the light flux density portion of the light flux emitted from the light source unit provided with the reflector as in the present invention.
[0069]
Further, in order to solve the problem of the color reproducibility of the above-mentioned projection display device, an illumination optical system having an auxiliary light source for generating two primary color lights has already been proposed (for example, see JP-A-2002-174854). . However, in this illumination optical system, the light beam from the auxiliary light source is incident on a part of the multi-lens array (preferably one lens cell in the multi-lens array) for uniformizing the light quantity distribution of the white light source. I have. The illumination optical system according to the present invention includes a second integrator section that is appropriate for each light beam from the auxiliary light source, and is configured so that the light flux from the peripheral auxiliary light source section can also have a uniform light amount distribution.
[0070]
Next, Embodiment 4 will be described as a specific embodiment of the projection display apparatus according to the present invention. Also in the fourth embodiment, the same components as those in the first to third embodiments are denoted by the same reference numerals unless otherwise specified, and the detailed description of the already described items is omitted.
[0071]
<Example 4>
FIG. 6 shows a schematic configuration of the projection display apparatus according to the present embodiment. This apparatus is an apparatus using the illumination optical system according to the first embodiment as a representative of the illumination optical system according to the present invention. The polarization conversion optical system 6 of the illumination optical system is the same as that of the third embodiment and is well known in the related art.
[0072]
This device illuminates a light valve composed of a transmission-type image display element that performs light modulation of an illumination light beam based on predetermined image information with an illumination light beam from an illumination optical system, and carries image information from the light valve. The light beam is projected via the projection optical system 67. The illumination light flux is transmitted from the illumination optical system of the present invention in a state where the light quantity distribution is made uniform by the first integrator unit 4, the second integrator unit, and the third integrator unit 5, and the polarization direction is made uniform by the polarization conversion optical system 6. Is emitted. Then, as shown below, the illumination light flux is decomposed into three primary color lights, light-modulated by liquid crystal panels 64a to 64c which are transmission image display elements for each color light, and these projection light fluxes are combined. The image is projected by the projection optical system 67 to form a full-color image on a screen (not shown). The first to third color light components described below can correspond to the three primary color lights of blue, green, and red in an arbitrary order.
[0073]
That is, the illumination light beams emitted from the illumination optical system are decomposed by the dichroic mirrors 62a and 62b, and applied to the liquid crystal panels 64a to 64c on which images for the first to third color light components are displayed. The dichroic mirror 62a separates the illumination light beam into a first color light component light beam and a combined light beam of the second and third color light components, and the dichroic mirror 62b combines the second and third color light components separated by the dichroic mirror 62a. The light beam is separated into a second color light component and a third color light component. On the optical path of the illumination light flux, total reflection mirrors 63 to d for deflection and condenser lenses 61 a to 61 f are arranged, and on the liquid crystal panels 64 a to 64 c, the main light source unit 1, the outer peripheral auxiliary light source unit, The light flux from the central auxiliary light source 2 is superimposed. The first to third color light components, which are projection light beams transmitted through the liquid crystal panels 64a to 64c and light-modulated based on predetermined image information, are combined with the dichroic film 65a that reflects the first color light component and the third color light component. The light is synthesized by a cross prism 66 having a reflecting dichroic film 65b therein.
[0074]
According to the present embodiment, by providing the illumination optical system according to the present invention, it is possible to obtain a projection-type display device that is compact, has high illumination efficiency, and can perform bright and uniform illumination while being compact.
[0075]
The projection display device of the present invention is not limited to the embodiment, and various modifications can be made. For example, the illumination optical system of the present invention can be used arbitrarily as the projection display of the present invention.
[0076]
Further, in the projection display device of the present invention, the light valve is not limited to the embodiment. For example, the illumination optical system of the present invention can be applied to a digital micromirror device (DMD) or a projection display device including a light valve formed of a reflective image display element. Further, the projection display device of the present invention is not necessarily limited to a color image display device, and may be a monochrome image display device.
[0077]
Further, as described above, the illumination optical system according to the present invention converts the light flux having an intensity peak in a wavelength range to be increased in the spectral distribution of the light flux emitted from the main light source unit into the peripheral auxiliary light source unit and / or the central auxiliary light source. The light source may be configured to emit light from at least one light source among a plurality of light sources constituting the unit. For example, as in this case, when the luminous flux from at least one of the light sources constituting the auxiliary light source unit is not white light and the light intensity is biased to a specific wavelength range, the auxiliary light source unit is configured. The luminous flux from at least one of the plurality of light sources is a light beam among the plurality of light valves of an apparatus configured to separate the illuminating light beam into color light, carry image information by the light valve for each color light, and then perform color synthesis. You may comprise so that only some light valves may be illuminated. For example, when the main light source unit emits white light and at least one of the auxiliary light source units is a red semiconductor laser, the light from this light source illuminates only the red component light valve. It may be.
[0078]
【The invention's effect】
As described above, according to the illumination optical system and the projection display apparatus using the same according to the present invention, the light flux emitted from the main light source unit including the light source and the reflector is located at the light flux low-density portion on the outer peripheral portion. It is provided with a peripheral auxiliary light source unit that emits a light beam so as to supplement the light beam, and is configured to be able to equalize the light amount distribution of each light beam from the main light source unit and the peripheral auxiliary light source unit, while being compact, An illumination optical system having high illumination efficiency and capable of performing bright and uniform illumination and a projection display apparatus using the same can be obtained.
[Brief description of the drawings]
FIG. 1 is a schematic configuration diagram of an illumination optical system according to a first embodiment of the present invention.
FIG. 2 is a diagram showing an intensity distribution of light reflected by a parabolic reflector;
FIG. 3 is a schematic configuration diagram of an illumination optical system according to a second embodiment of the present invention.
FIG. 4 is a schematic configuration diagram of an illumination optical system according to a third embodiment of the present invention.
FIG. 5 is a spectral distribution diagram of wavelengths in a visible region of an ultra-high pressure mercury lamp.
FIG. 6 is a schematic configuration diagram of a projection display apparatus according to a fourth embodiment of the present invention.
[Explanation of symbols]
1 main light source
2 Central auxiliary light source
3 Deflection mirror
4 First integrator section
5 Third integrator
6. Polarization conversion optical system
7, 66 cross prism
8 Peripheral auxiliary light source
9 Second integrator
11,56 light source
12,57,104 Parabolic reflector
15 2nd fly eye
16 First fly eye
17, 18, 48, 49 lens cells
19 Polarization separation film
20 Reflective film
21 λ / 2 phase film
22 Prism surface
31, 52 Semiconductor laser
35, 53 Collimator lens
36 Rod Integrator
37, 38, 47, 55, 61 Condensing lens
58 2nd fly eye corresponding to peripheral auxiliary light source
59 1st fly eye corresponding to outer peripheral auxiliary light source
62 dichroic mirror
63 total reflection mirror
64 transmissive liquid crystal panel
65 dichroic membrane
67 Projection optical system
101 arc tube
108 luminous point

Claims (8)

A main light source unit including a light emitter and a reflector that reflects light emitted from the light emitter toward the object to be illuminated; a main integrator unit for equalizing the amount of light flux from the main light source unit; and a main light source unit. An outer peripheral auxiliary light source unit that emits a light beam so as to supplement a light beam in a low-density portion of an outer peripheral portion of the emitted light beam, and an outer peripheral auxiliary integrator unit that equalizes the light amount of the light beam from the outer peripheral light source unit An illumination optical system, characterized in that: A main light source unit including a light emitter and a reflector that reflects light emitted from the light emitter toward the object to be illuminated; a main integrator unit for equalizing the amount of light flux from the main light source unit; and a main light source unit. An outer peripheral auxiliary light source unit that emits a light beam so as to supplement the light beam in a low-density portion of the outer peripheral portion of the emitted light beam, and the light beam emitted from the outer auxiliary light source unit has a light amount distribution substantially in an emitted state. An illumination optical system, wherein the illumination optical system is uniform, and means for uniformizing the amount of light flux from the outer peripheral auxiliary light source unit is omitted. The illumination optical system according to claim 1, further comprising a central auxiliary light source unit that emits a light beam so as to supplement the light beam in a low-density portion near the center of the light beam emitted from the main light source unit. The illumination optical system according to any one of claims 1 to 3, wherein the outer peripheral auxiliary light source unit includes a plurality of light sources. The outer peripheral auxiliary light source section includes a plurality of light sources that emit light beams at positions in the light flux density portion of the outer peripheral portion that are substantially rotationally symmetric with respect to the optical axis of the reflector. Item 5. The illumination optical system according to item 4. A pupil plane of the illumination optical system and an irradiation surface with a light beam emitted from the main light source unit are configured to partially overlap with each other in a cross section orthogonal to an optical axis at a pupil position of the illumination optical system. The peripheral auxiliary light source unit that emits a light beam so as to supplement a light beam in a portion where the pupil surface protrudes from the irradiation surface out of a portion where the pupil surface and the irradiation surface do not overlap with each other. The illumination optical system according to any one of claims 1 to 5. The illumination optical system according to claim 6, wherein the reflector is a rectangular reflector that emits a light beam having a substantially rectangular shape in a cross section orthogonal to the optical axis. An illumination optical system according to any one of claims 1 to 7, wherein the light from the illumination optical system illuminates at least one light valve that performs light modulation of the illumination light based on predetermined image information. A projection type display device characterized by projecting a light beam carrying image information from the light valve via a projection optical system.

Images