JP2008145666A - Illuminating device and image projection apparatus using same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reduce the occurrence of ghost light caused by unnecessary light passing through the central area of the pupil in an illuminating optical system, in an illuminating device and an image projection apparatus using the same. <P>SOLUTION: The illuminating device 200 has an illuminating optical system 20 including: a surface light source 1; a condenser lens 2 for condensing light from the surface light source 1; and a relay optical system for relaying light from the condenser lens 2 to a surface to be illuminated. The relay optical system has a field lens 11. In addition, a light shield member 3 for regulating the range of light transmission is disposed on an optical axis between the surface light source 1 and the pupil 6 in the illuminating optical system 20. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an illumination device and an image projection device using the illumination device.

2. Description of the Related Art Conventionally, as an image projection apparatus, an image projection apparatus that irradiates a reflective display element with illumination light through an illumination optical system and projects a display image by the reflective display element with a projection optical system is known. In such an image projection apparatus, the illumination light emitted from the light source and passed through the pupil of the illumination optical system is relayed to the display element surface by the relay lens and the field lens that form the illumination optical system, and modulated by the display element. In many cases, image projection is performed such that light passes through the field lens again and is incident on the pupil of the projection optical system so that an image on the display element surface is formed on the projection surface.
In such an image projection device, illumination light from the illumination optical system or projection light reflected by the display element is scattered or reflected by optical members or mechanism members in the optical path, and reaches the projection surface to generate ghost light. There are things to do. Such ghost light may reduce the contrast of the projected image, causing a reduction in image quality. In particular, the surface reflected light of the illumination light from the optical member arranged between the pupil of the projection optical system represented by the field lens and the display element easily enters the pupil of the projection optical system and easily becomes ghost light. If an antireflection film is attached to the surface of these optical members, the surface reflected light intensity can be reduced compared to the projected light intensity. However, in order to meet the high contrast performance requirements of recent image projectors, such ghost light is also used. Should be prevented.
In order to prevent such image quality degradation due to ghost light, it is conventionally known to provide a light shielding member in the optical path of the optical system. In order to effectively shield the ghost light without affecting the uniformity of the illuminance of the projected image, this light shielding member is located at or near the position of the entrance pupil of the projection optical system and the pupil of the illumination optical system conjugate with it. Was placed in position.
For example, Patent Document 1 discloses a light-shielding plate (light-shielding member) that shields a part of an illumination light beam near a pupil position of an illumination optical system, that is, a substantial pupil position in a projection-type image display device using a reflective display element. ) Is described.
In Patent Document 2, an aperture stop and an illumination light stop are respectively disposed as light shielding members on the pupil of the projection optical system and the pupil of the illumination optical system conjugate with the pupil.
Further, in Patent Document 3, a light shielding member is disposed in the vicinity of the pupil of the projection optical system.
JP 2004-258439 A JP-A-8-251520 JP 2000-338448 A

However, the conventional illumination device as described above and the image projection device using the same have the following problems.
In conventional image projection apparatuses, since the light shielding member is arranged on the pupil of the illumination optical system or the pupil of the projection optical system, the light that causes the ghost light or the ghost light is transmitted through the central region of each pupil. The other necessary light passing through the central region of the pupil must be shielded together. For this reason, there is a problem in that the amount of necessary light is reduced and the projected image is reduced in luminance or the luminance is biased, resulting in a reduction in image quality.
The light that causes such ghost light is likely to be generated by off-axis light having a large incident angle from the light source to the illumination optical system, and is particularly noticeable when, for example, a surface light source such as an LED light source is used. Is.

  The present invention has been made in view of the above problems, and an illumination apparatus capable of reducing the generation of ghost light due to light passing through the central region of the pupil of an illumination optical system and image projection using the same An object is to provide an apparatus.

In order to solve the above-described problems, an illumination device according to the present invention includes a light source, a condensing optical system that condenses light from the light source, and a relay that relays light from the condensing optical system to an illumination target surface. An illumination apparatus having an illumination optical system including an optical system, wherein the relay optical system has a field lens in front of an illuminated surface, and is on an optical path between the light source and a pupil position of the illumination optical system. The light-shielding member that restricts the light transmission range is provided.
According to the present invention, the light shielding member is disposed on the optical path between the light source and the pupil position of the illumination optical system to regulate the light transmission range, so that the incident angle of the light incident on the illumination optical system from the light source can be reduced. The size can be regulated. Therefore, it is possible to reduce light that enters the illumination optical system at a large incident angle and passes through the central region of the pupil of the illumination optical system and becomes ghost light.

In addition, the image projection apparatus of the present invention is illuminated by the illumination apparatus of the present invention, a reflective display element disposed on a surface to be illuminated by the illumination apparatus, and the field lens of the illumination apparatus, and is reflected. A projection optical system that projects light reflected by the display surface of the display element through the field lens again is used.
According to the present invention, since the illumination device according to the present invention is used, a ghost generated when the light incident on the illumination optical system at a large incident angle and passing through the central region of the pupil of the illumination optical system is reflected on the surface by the field lens. Light can be reduced.

  According to the illumination device and the image projection device of the present invention, light having a large incident angle incident on the illumination optical system can be blocked and light passing through the central region of the pupil can be reduced, so that the light passes through the central region of the pupil. It is possible to reduce the generation of ghost light due to the light that is transmitted.

Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.
An image projection apparatus according to an embodiment of the present invention will be described.
FIG. 1 is a schematic optical path diagram in plan view showing a schematic configuration of an illumination apparatus and an image projection apparatus using the same according to an embodiment of the present invention. FIG. 2 is a side view of FIG.

The image projection apparatus 100 according to the present embodiment illuminates a reflective display element and projects a full-color image displayed on the reflective display element, and is suitable for, for example, a projection television and a video projector. is there.
As shown in FIG. 1, the schematic configuration of the image projection apparatus 100 includes a surface light source 1, an illumination optical system 20, a light shielding member 3, a relay lens 7, a field lens 11, a reflective display element 8, and a projection optical system 13. .
In addition to this, a well-known control unit such as a light emission control unit that controls the light emission timing of the surface light source 1 and a modulation element control unit that performs drive control of the reflective display element 8 according to an image signal is provided. Illustration is omitted.
Here, the surface light source 1, the illumination optical system 20, the light blocking member 3, the relay lens 7, and the field lens 11 constitute the illumination device 200 of the present embodiment.

The surface light source 1 generates light of each wavelength of red (R), green (G), and blue (B) that illuminates the reflective display element 8, and in this embodiment, three types corresponding to the respective wavelengths. LED. The shape of the light emitting surface of each LED is rectangular as shown in FIG.
In FIG. 1, for simplicity of illustration, only one surface light source 1 is shown.

In the illumination optical system 20, a condensing lens 2 corresponding to each surface light source 1, a color composition member 4 and an integrator 5 common to each surface light source 1 are arranged in order from the surface light source 1 side.
The condensing lens 2 condenses each wavelength light generated by each surface light source 1 and makes it incident on the integrator 5, forms a secondary light source of the surface light source 1 on the image side of the integrator 5, and illuminates it. It is a lens group for making the pupil of the system.
In the present embodiment, in order to obtain the required efficiency according to the etendue of the illumination optical system, it is designed with an appropriate NA and emission diameter (focal length), and from the surface light source 1 side, the first lens 2A, the first lens Two lenses 2B are used. The focal position of the condenser lens 2 is set to the center O of the light emitting surface of the surface light source 1.

The color synthesizing member 4 is disposed on the optical path between each condenser lens 2 and the integrator 5, synthesizes the light collected by each condenser lens 2, and the optical axis L _{1 of the} integrator 5. It is an optical element for making it enter. For example, it includes a dichroic prism, a dichroic mirror, and the like.
Hereinafter, for the sake of brevity, the description will be made using the optical path related to one surface light source 1 shown in FIG. That is, a description will be given of a case where the surface light source 1, the optical axis of the condenser lens 2 and the optical axis L ₁ of the integrator 5 are consistent. Unless otherwise specified, the description will be given assuming that the optical axis L ₁ is the optical axis of the illumination optical system 20. The optical paths and positional relationships from the other surface light sources 1 can be easily understood by paying attention to the fact that the optical axis is reflected by the color composition member 4.

The integrator 5 is an optical system that makes the light quantity distribution of incident light substantially uniform, and it is possible to employ integrator optical systems having various known configurations. In the present embodiment, a configuration using a fly-eye lens is employed.
Since the visibility, but the simplified illustration, the optical axis L ₁ of the illumination optical system 20 including an integrator 5, in this embodiment, deeper than the paper forward a parallel to the plane of FIG. 1 Exists in the direction.

The light shielding member 3 is for restricting the light transmission range between the pupil 6 of the illumination optical system 20 and the surface light source 1, and is provided corresponding to each surface light source 1.
In the present embodiment, as shown in FIG. 2, between the surface light source 1 and the first lens 2A, an end portion parallel to one side of the rectangular shape of the light emitting surface of the surface light source 1 is connected to the optical path from the outer peripheral side of the optical path. It consists of the light-shielding plate which protrudes toward the inner side of the. One side of the light emitting surface on which the light shielding members 3 are arranged in parallel is a long side in this embodiment, but may be a short side.

The light shielding member 3 of this embodiment forms an asymmetric light shielding range with respect to the optical axis L ₁ of the illumination optical system 20. This is because, as described later, in the present embodiment, the angular distribution of light becomes ghost light because that is asymmetrical with respect to the optical axis L _1.
Here, the ghost light refers to unnecessary light that is not supposed to reach the image plane due to optical design, and is, for example, surface-reflected by a light transmission surface of the optical system after exiting the illumination optical system 20. This means light that finally reaches the image plane.

The relay lens 7 constitutes a relay optical system together with the field lens 11 so that the illumination light emitted from the pupil 6 of the illumination optical system 20 can be relayed to the display surface 8a of the reflective display element 8 described later. Yes.
In the present embodiment, the reflection mirror 10 is disposed between the relay lens 7 and the field lens 11, the illumination light path is bent, and the illumination light is obliquely incident on the optical axis L ₂ of the field lens 11. Yes.
Here, the angle of inclination of the optical axis L ₁ incident on the field lens 11 from the optical axis L ₂ is represented by an angle φ.

The field lens 11 constitutes a relay optical system together with the relay lens 7 and relays the light emitted from the pupil 6 onto the display surface 8a, and the light reflected by the on-state micromirror of the reflective display element 8 described later. Is made incident on the pupil 12 of the projection optical system 13.
Field lens 11, in this embodiment, the optical axis L ₂ of the field lens 11 is disposed in proximity to the reflection type display device 8 in parallel to the normal of the display surface 8a of the reflection type display device 8.

The reflective display element 8 displays an image by spatially modulating the irradiated light by controlling the reflection characteristics of a plurality of display elements arranged in a two-dimensional lattice pattern on the display surface 8a. As the reflective display element 8, for example, a DMD (micro-mirror) in which micromirrors whose inclination angles are changed to two kinds of inclination angles of an on state and an off state according to an image signal are arranged in a two-dimensional lattice pattern as display elements. Devices such as Digital Micro mirror Device) can be employed.
In the present embodiment, DMD is employed in which the inclination angles with respect to the normal line of the display surface 8a are ± θ. The inclination angle θ is a small angle such as 10 ° or 12 °, for example.
Then, the incident angle to the DMD axis principal ray of the illumination light with respect to the display surface 8a, by the inclination angle φ of the illumination optical axis L ₁ incident appropriately set field lens 11, the inclination direction of the micro-mirror in the ON state It is inclined by 2 · θ toward (the right side in FIG. 1).
In FIG. 1, reference numeral 9 denotes a cover glass that covers the display surface 8 a of the reflective display element 8.

The projection optical system 13 reflects the light that is reflected by the on-state micromirror of the reflective display element 8 and is incident on the pupil 12 via the field lens 11 out of the illumination light irradiated on the reflective display element 8. The light reflected by the off-state micromirror of the reflective display element 8 is transmitted through the field lens 11 and guided to the outside of the pupil 12. .
In the present embodiment, the optical axis of the projection optical system 13 is arranged coaxially with the optical axis L ₂ of the field lens 11.

Although the side view of FIG. 1 are not shown to become complicated in this embodiment, since the optical axis L ₁ are present in the depth direction than the paper before, directed from the relay lens to the field lens 11 The optical path of the illumination light and the optical path of the projection light directed from the field lens 11 toward the projection optical system 13 are three-dimensionally crossed in the depth direction of the paper surface, and the reflection mirror 10 is disposed at a position where the projection light is not blocked.

Next, the operation of the image projection apparatus 100 of the present embodiment will be described focusing on the operation of the light shielding member 3. However, since the action of the light shielding member 3 is common to each surface light source 1, the following description will be made based on the optical path of light emitted from one surface light source 1 shown in FIG.
FIG. 3 is a conceptual diagram of an optical path of light that can be ghost light of the image projection apparatus according to the embodiment of the present invention. FIG. 4 is an optical path diagram showing details of the optical path in the vicinity of the light source in FIG.

The light emitted from the surface light source 1 is radiated from the entire light emitting surface toward the first lens 2A at a predetermined divergence angle. At this time, as shown in FIG. 1, the light emitted from the center O of the light emitting surface of the surface light source 1 is condensed by the condenser lens 2 through an optical path that is not shielded by the light shielding member 3, and is substantially parallel light. The light is emitted from the second lens 2B, passes through the color composition member 4, and reaches the integrator 5.
The light beam reaching the integrator 5 is split by each cell constituting the fly-eye lens by the action of the fly-eye lens, and forms a secondary light source at the position of the pupil 6 substantially corresponding to the fly-eye exit surface.
Then, the light emitted from each secondary light source sequentially passes through the relay lens 7, the reflection mirror 10, the field lens 11, and the cover glass 9, and is superimposed on the display surface 8 a of the reflective display element 8. The reflective display element 8 is uniformly irradiated over the entire surface.

The reflective display element 8 is driven based on the image signal by a modulation element control unit (not shown), and all the micromirrors are inclined to either the on state or the off state.
Only the light reflected by the on-state micromirror is incident on the pupil 12 of the projection optical system 13 by the action of the field lens 11. This light is projected by a projection optical system 13 onto a projection surface (not shown) composed of an appropriate screen or the like.

  On the other hand, light emitted from a position other than the center O of the light emitting surface of the surface light source 1 and incident on the first lens 2A passes through the second lens 2B and the integrator 5, passes through the pupil 6, and is the same as described above. Most of the light is projected onto the projection surface, but since each light is off-axis light, each optical path is different. In particular, since light incident on the first lens 2A at a large incident angle from the outer peripheral side of the surface light source 1 travels along an optical path that is significantly different from axial light, ghost light is likely to occur in a part of the off-axis light beam. There is a problem.

In the present embodiment, the light serving as the ghost light is shielded by providing the light shielding member 3 between the surface light source 1 and the first lens 2A.
FIG. 3 shows the condensing lens 2 out of the light emitted from the point P ₁ at the end of the surface light source 1 on the light shielding member 3 side and the point P ₂ at the end (upper side in the drawing). ₂ conceptually shows the optical paths of the light beams Q ₁ and Q ₂ incident at the largest incident angle. Here, although the light rays Q ₁ and Q ₂ are symmetric with respect to the optical axis L ₁ , the light ray Q ₁ is within the light shielding range of the light shielding member 3, and therefore the following description is for the optical path when the light shielding member 3 is not disposed. Explain.

Since the light beams Q ₁ and Q ₂ are incident on the effective outer peripheral portion of the condenser lens 2 at a large incident angle from a position shifted from the optical axis L ₁ , the light rays Q ₁ and Q ₂ are subjected to a strong refraction action by the condenser lens 2, and are shown in FIG. as shown, it is emitted in a direction intersecting the optical axis L _1. Then, proceed integrator 5, the pupil 6, the central area of the relay lens 7 obliquely, respectively intersect the optical axis L _1, the routine proceeds to the opposite side with respect to the optical axis L _1, incident on the reflecting mirror 10, the field of view The lens 11 is reached.
Here, the actual optical path of the light beams Q ₁ and Q ₂ is a complicated optical path because it passes through the integrator 5. In order to explain the generation principle of ghost light, the integrator 5 is represented by a light beam that travels substantially straight. Yes.

Since the optical axis L ₁ incident on the field lens 11 is inclined by an angle φ with respect to the optical axis L ₂ of the field lens 11 and the projection optical system 13, the light beam Q ₁ (Q ₂ ) is the optical axis L _2. Is incident on the field lens 11 at an angle shallower than φ. The light beam Q ₁ (Q ₂ ) is incident on the lens surface of the field lens 11 from a position in the direction in which the angle φ decreases (increases) with the optical axis L ₁ as a reference. Therefore, in the example of ray tracing shown in FIG. 3, a part of each of the rays Q ₁ and Q ₂ is reflected on the surface of the field lens 11 as rays q ₁ and q ₂ that are directed in different directions, and the ray q _1. Enters the pupil 12 of the projection optical system 13, and the light ray q ₂ travels toward the outside of the pupil 12.
Which of light on the pupil 12 enters, depending on the size and position of the pupil 12 of the angle phi, in general, shallow angle of incidence with respect to the viewing lens 11, the reflected light with respect to the optical axis L ₂ It is easier to enter the pupil 12 if you proceed at a shallow angle.

For this reason, the light beam q ₁ becomes ghost light projected onto the projection surface by the projection optical system 13. Since this light is not reflected by the reflective display element 8, it has nothing to do with the image corresponding to the image signal, and becomes image noise, which reduces the image quality of the projected image.
In the present embodiment, the light shielding member 3, for shielding light Q _1, such ghost light is eliminated, it is possible to prevent degradation in the image quality of the projected image.
In the case where the optical axis L ₁ of the illumination light is inclined by the angle φ from the optical axis L _{2 of} the projection optical system 13 and the field lens 11 as in this embodiment, it corresponds to the asymmetry of such an arrangement. in the vicinity of the surface light source 1, it is preferable to dispose the light shielding member 3 in a position relationship as to block light traveling at large angles of incidence from the decreasing direction side of the region of the inclination angle φ with respect to the optical axis L _1.

The arrangement position of each light shielding member 3 corresponding to each surface light source 1 can be set by simulating a light ray range that becomes ghost light by ray tracing.
For example, in FIG. 4, a light beam of a light beam that is incident on the first lens 2 </ _b > A with a large incident angle from a point P ₁ , a point O, and a point P ₂ on the surface light source 1 corresponding to one wavelength light. A tracking chart is shown.
According to FIG. 4, the incident image height with respect to the first lens 2A decreases in this order in the light beams emitted from the point P ₁ , the point O, and the point P _2, but the image height position is reversed when transmitted through the second lens 2B. and the point O, the light beam C from the point P _2, D proceeds at a shallow angle with respect to the optical axis L _1, the process proceeds the light beam B from the point P ₁ with the largest inclination relative to the optical axis L _1. Therefore, it can be seen that the light beams C and D do not become ghost light. Therefore, the light shielding member 3 is set at a position where the light beam B is shielded and the light beams C and D are not shielded.
The position of the light shielding member 3 arranged with respect to the surface light source 1 corresponding to the different wavelength light is set to each optimum position based on the simulation using the corresponding wavelength light.

  Since the above is substantially the same for other light on the outer peripheral side of the light emitting surface of the surface light source 1, the end of the light shielding member 3 extends in parallel to one side of the light emitting surface of the surface light source 1. Thus, the light that is emitted from the outer periphery of the light emitting surface of the surface light source 1 and becomes ghost light can be similarly removed.

The light shielded by the light shielding member 3 passes through the central region of the pupil 6 of the illumination optical system 20 when the light shielding member 3 is not disposed. Therefore, if the light shielding member is arranged and removed at the pupil position of the illumination optical system or the projection optical system as in the prior art, the light shielding member has to be arranged in the central region of the pupil position. The other necessary light and the necessary light for forming the projected image are also shielded from many parts, and a reduction in luminance and image quality are inevitable.
On the other hand, in the present embodiment, since the light beam emitted from the surface light source 1 is shielded from the outer peripheral direction, most of other necessary light that does not cause ghost light is transmitted. For this reason, only a light beam (for example, the light beam B) that can cause ghost light can be mainly shielded, and a reduction in luminance due to shielding of necessary light can be reduced to a minimum.

  In particular, in the present embodiment, the light collected by the condenser lens 2 is transmitted through the integrator 5 so that the light quantity distribution of the light beam that illuminates the reflective display element 8 is made uniform. For this reason, even if the light necessary for illumination is blocked by the light blocking member 3, the uniformity of the integrator 5 arranged on the reflective display element 8 side further reduces the image quality due to luminance unevenness. Don't make it happen. Further, even if there is a decrease in luminance light quantity due to light shielding, it can be sufficiently compensated by slightly increasing the light output of the surface light source 1.

Thus, according to the illuminating device 200 of this embodiment, the provision of the light blocking member 3 can reduce the generation of ghost light due to the light passing through the central region of the pupil 6. Therefore, compared with the case where light is shielded at the pupil position of the illumination optical system or the projection optical system, the luminance is reduced and high-quality illumination can be performed.
In addition, the image projection apparatus 100 according to the present embodiment can project an image with good image quality by using such an illumination apparatus 200.

  In the above description, the example in which the integrator 5 is provided has been described. However, for example, when sufficient light quantity uniformity is obtained depending on the type of light source, the allowable range of the light quantity distribution of illumination light, and the like, the integrator 5 is provided. It is good also as a structure which deleted.

In the above description, the light shielding member 3 is described as an example in the case where it is arranged on the optical path between the surface light source 1 and the first lens 2A, that is, on the optical path between the light source and the condensing optical system. The light shielding member 3 may be disposed anywhere as long as it is between the pupil 6 of the illumination optical system 20 and the surface light source 1.
For example, they may be arranged at appropriate positions such as between the first lens 2A and the second lens 2B, near the exit of the second lens 2B, between the condenser lens 2 and the integrator 5, and near the exit of the integrator 5. it can.
Preferably, it arrange | positions on the optical path between the optical elements which comprise a condensing optical system between a light source and a condensing optical system. At such a position, incident light having a large angle that generates ghost light passes through the effective outer peripheral portion of the optical system. Therefore, the shielding member can be disposed from the outside of the effective luminous flux of the optical system, and the necessary illumination light can be blocked. This is because it is possible to reduce the decrease in brightness due to the light and to efficiently block off-axis light that passes near the pupil center as ghost light.

In the above description, the example in which the light source is the surface light source 1 has been described. However, the light source is not limited to the surface light source, and includes a case where the light emitting unit has a finite size. For example, when a light emitting unit such as a lamp has a finite size, off-axis light that causes ghost light may be generated like a surface light source.
Moreover, even if it is a substantial point light source, when the position of the light source is shifted from the optical axis, all of the light becomes off-axis light, so that similar ghost light may be generated.

  In the above description, as an example of light that becomes ghost light, an example in which the surface reflection light of the field lens 11 is examined and the light shielding range is set has been described. It is preferable to consider all possible cases. For example, it is preferable to study the back surface reflected light of the field lens 11 and optical elements other than the field lens 11 as necessary.

  In the above description, the example in which the optical path of the illumination light is folded by the reflection mirror 10 has been described. However, such an optical layout is an example, and the reflection mirror 10 is omitted and the relay lens 7 is used. A layout in which the emitted illumination light directly enters the field lens 11 may be adopted.

In the above description, the surface light source 1 is provided with three types that generate R, G, and B wavelength light, and the light shielding member 3 is provided for each. However, no ghost light is generated. If there is wavelength light, the corresponding light shielding member 3 may be omitted.
Further, in the case of a monochrome illumination device or a color illumination device using white light and a filter switching mechanism, the color synthesis member 4 may be omitted and the surface light source 1 may be configured as one type.

In the above description, the illumination device 200 is described as an example of the illumination device used in the image projection device used with the reflective display element. However, the illumination device collects the light from the light source and the light from the light source. And a relay optical system that relays light from the light collection optical system to the surface to be illuminated, the illumination optical system having the illumination optical system in front of the surface to be illuminated As long as the illumination device has a field lens, the illumination device is not particularly limited to an illumination device used for an image projection device using a reflective display element. For example, an illumination device used for an image projection device using a transmissive display element may be used.
Moreover, it is not limited to the illuminating device used for an image projector. For example, it may be an illuminating device used for an image observation apparatus that images an image on an illuminated surface through an imaging optical system. In this case, the ghost light reflected by the surface of the field lens or the like and entering the imaging optical system can be reduced by the light shielding member 3.

  In addition, the constituent elements described in the above embodiments can be implemented in appropriate combination within the scope of the technical idea of the present invention, if technically possible.

Here, a case will be described where the names of the correspondence relationship between the terminology of the above embodiment and the terminology of the claims are different.
The surface light source 1 is an embodiment of a light source. The condensing lens 2 is an embodiment of a condensing optical system. The integrator 5 is an embodiment of a homogenizing optical system. The relay lens 7 and the field lens 11 are an embodiment of a relay optical system. The display surface 8a of the reflective display element 8 corresponds to the illuminated surface.

It is a typical optical path figure of planar view which shows schematic structure of the illuminating device which concerns on embodiment of this invention, and an image projector using the same. It is A view side view of FIG. It is a conceptual diagram of the optical path of the light which can become ghost light of the image projector which concerns on embodiment of this invention. FIG. 4 is an optical path diagram showing details of an optical path in the vicinity of the light source in FIG. 3.

Explanation of symbols

1 Surface light source (light source)
2 Condensing lens (Condensing optical system)
2A 1st lens 2B 2nd lens 3 Light shielding member 4 Color composition member 5 Integrator (homogenization optical system)
6 pupil (pupil of illumination optics)
7 Relay lens 8 Reflective display element 8a Display surface 11 Field lens 12 Pupil (Pupil of projection optical system)
13 Projection Optical System 20 Illumination Optical System 100 Image Projection Device 200 Illumination Device

Claims (3)

An illumination apparatus having an illumination optical system comprising a light source, a condensing optical system that condenses light from the light source, and a relay optical system that relays light from the condensing optical system to an illuminated surface,
The relay optical system has a field lens in front of the illuminated surface,
An illuminating device comprising: a light shielding member for restricting a light transmission range on an optical path between the light source and a pupil position of the illumination optical system.   The illumination apparatus according to claim 1, wherein the illumination optical system includes a uniformizing optical system that is placed in the vicinity of a pupil position of the illumination optical system and substantially uniformizes a light amount distribution on the illuminated surface. . The lighting device according to claim 1 or 2,
A reflective display element disposed on a surface to be illuminated by the illumination device;
An image projection apparatus comprising: a projection optical system that projects light transmitted through the field lens of the illumination apparatus and reflected by the display surface of the reflective display element through the field lens again.

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