JP2000122000A - Illumination device and image display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable illumination excellent in uniformity at a minimum cost increase without changing the size of the device. SOLUTION: This illumination device 200 has a turn back mirror 202 having a first reflection surface on an incident side and a second reflection surface approximately parallel therewith from a light source 204 to a surface 203 to be illuminated or between light valves. The first reflection surface has the characteristic to reflect only the light of the desired polarization direction and to be transparent to the other and the rear surface thereof has the second reflection surface having the characteristic to reflect the light transmitted through the first reflection surface. As a result, the two light source images to the surface 203 to be illuminated are formed apart a distance and, therefore, the nonuniformity in the light source section 201 and the illumination optical system may be improved to the direction limit or below.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an illuminating device which requires uniform illumination, an image display device for dimming light from a light source by a light valve and displaying an image, and a projection type image display device.

[0002]

2. Description of the Related Art At present, the market for projectors, mainly for projection type image display devices using transmission type liquid crystal light valves, is rapidly expanding. As the market expands and matures, the development of technologies for higher brightness is being promoted mainly in order to differentiate from other companies.One of the efforts is to improve the light utilization rate by shortening the arc of the light source optically. There is. As a result, the brightness can be improved without increasing the power consumption. On the other hand, by using a point light source, the brightness unevenness on the light source or the reflector that guides the light of the light source to the entire surface causes uneven brightness or color unevenness on the projected image. It has appeared. As a countermeasure against this, color unevenness can be improved by dividing a light beam from a light source into several partial light beams in an illumination optical system and superimposing each light beam on a light valve. This optical system is called an integrator optical system and has been introduced in many products.

[0003] Similarly, an integrator optical system is used for an exposure apparatus for semiconductor manufacturing which also requires uniformity for the same reason. In addition, since the size of direct-view type liquid crystal panels will increase in the future, image display devices and other lighting devices that use them will require highly uniform images without luminance and color unevenness. It will be taken.

[0004] A conventional schematic basic configuration of the projection type image display device described above will be described below with reference to FIG.

A light source 101 and an illumination optical system 102
(Integrator optical system), a color separation optical system 103, a relay optical system 104, a light valve unit 105, a color combining optical system 106, and a projection optical system 107. The light source unit 101 includes a light source 108 that forms an arc by electric discharge between the electrodes to generate randomly polarized light, and a reflector 109 that reflects light from the light source 108 in one direction on its rotational symmetry axis. Light from the light source 101 enters the illumination optical system 102. In this example, an integrator optical system is used and includes a light source side micro lens array (hereinafter, first lens array 110) and a light valve side lens array (hereinafter, second lens array 111).
As shown in FIG. 12, a large number of rectangular microlenses similar to a light valve opening described later are arranged.

The second lens array 111 is composed of the same number of microlenses as the microlenses forming the first lens array 110. With this lens, each microlens image on the first lens array is superimposed on the light valve opening. Is formed. Light emitted from the illumination optical system 102 enters the color separation optical system 103. First, of the light incident on the blue transmission dichroic mirror 112, the blue light passes therethrough and is reflected by the total reflection mirror 113, passes through the condenser lens 114, and passes through the light valve unit 115 for blue.
Leads to. The green light and red light reflected by the blue transmission dichroic mirror 112 are incident on a green reflection dichroic mirror 116, of which the green light reaches a green light valve unit 118 via a condenser lens 117. The red light is transmitted through the green reflecting dichroic mirror 116, and the relay optical system 1
04.

The incident red light is incident on the incident side lens 119,
The light reaches a red light valve unit 124 via a total reflection mirror 120, an intermediate lens 121, a total reflection mirror 122, and a condenser lens 123. As described above, the light valve unit 105 is arranged for each color light as the blue light valve unit 115, the green light valve unit 118, and the red light valve unit 124. As shown in FIG. 13, the light valve 105 is
5, a liquid crystal panel 126, and an output-side polarizing plate 127. The input-side polarizing plate 125 transmits, for example, light having a rectangular outer shape shown in FIG. It is assumed that the setting is made to absorb light in the direction.

The light transmitted through the incident side polarizing plate 125 enters the liquid crystal panel 126. The liquid crystal panel 126 can change the polarization direction of transmitted light for each of a large number of pixel openings by an external signal. Here, when each pixel is not driven, the polarization direction is rotated by 90 degrees, and when the pixel is driven, light is transmitted without a change in the polarization direction. Outgoing side polarizing plate 1
27 has a polarization characteristic in a direction orthogonal to the incident side polarizing plate 125. Therefore, the polarization direction of the light of the pixel portion transmitted by the liquid crystal panel 126 with the polarization direction changed by 90 degrees is changed to the emission side polarization plate 12.
7 passes through here because it coincides with the transmission axis 7.

On the other hand, the light in the polarization direction of the pixel portion, which is transmitted through the liquid crystal panel 126 without changing the polarization direction, is emitted from the output side polarizing plate 12.
7 is absorbed here because it is orthogonal to the transmission axis. The light transmitted through the light valve unit 105 in this manner enters the color combining optical system 106. The color combining optical system 106 is a color combining prism 130 formed by bonding four triangular prisms such that the blue reflecting dichroic mirror surface 128 and the red reflecting dichroic mirror surface 129 are arranged orthogonally.
The blue light and red light incident here are reflected and projected by the projection optical system 10.
7 is incident. Green light is blue reflective dichroic mirror surface 1
28 and the red reflecting dichroic mirror surface 129 and enter the projection optical system 107. In this manner, the image on the light valve unit 105 is enlarged and projected by the projection optical system 107 on a screen not shown.

[0010]

The projection-type image display apparatus described above shows a typical configuration currently provided for presentations. Here, the occurrence of luminance unevenness and color unevenness on the projected image is a problem. The causes of luminance unevenness and color unevenness are (1) the light source itself.
(2) Due to non-uniformity of the reflection characteristics of the reflector.
(3) The shadow of the electrode line crossing the reflector opening of the light source. (4) Each optical component is displaced from the design position. (5) Image reversal in the relay optical system. (6) Due to non-uniformity of in-plane characteristics of each optical component. Is an optical factor. The above (2),
(4) and (6) depend on manufacturing factors, but the other ones occur at the current stage in the configuration and cannot be completely avoided.

The current solution to the problem of the unevenness is to divide the light beam from the light source into nearly 100 light beams in order to completely reduce the brightness unevenness or the color unevenness below the detection limit. However, at this time, when the integrator optical system that forms the partial light beam is the general lens array type described above, each micro lens that forms the lens array becomes very small, and considering the precision in forming parts, the There is a concern that the uniformity of illumination may be reduced due to sagging of the lens periphery. Further, the relationship between the distance between the two lens arrays forming the lens array type integrator optical system and the distance between the second lens array and the light valve is determined by the size ratio between the micro lens array forming the first lens array and the light valve. Decided. Therefore, as described above, if the number of light beams from the light source to be divided into partial light beams can be restricted to 100 or more, the arrangement of the lens array can be restricted naturally.
In the design of the apparatus, there may be a case where a reduction in size and weight is inconvenient.

The problem of solving the uneven brightness and the uneven color can be said to be the same for the illumination device and the image display device which require uniformity as described above. However, 1-6 mentioned above
Needless to say, 5 of the causes of the uneven brightness and uneven color does not necessarily apply to those having no relay optical system.

[0013]

According to a first aspect of the present invention, there is provided an illumination apparatus including a light source unit that emits randomly polarized light and an illuminated unit. A first reflecting means for selectively reflecting any polarized light therebetween and transmitting another polarized light, and a reflecting surface substantially parallel to the first reflecting means, the characteristics of which are at least the first reflecting surface. It is characterized by comprising a second reflecting means for reflecting transmitted polarized light.

In order to solve the above-mentioned problems, an image display device according to a second aspect of the present invention includes a light source unit that emits randomly polarized light,
A light valve section for dimming incident light using polarized light, a first reflection between the light source section and the light valve section that can selectively reflect any polarized light and transmits another polarized light; Means, a reflecting surface substantially parallel to the first reflecting means,
The characteristic is characterized by comprising a second reflecting means for reflecting at least polarized light transmitted through the first reflecting surface.

According to a third aspect of the present invention, there is provided an image display apparatus comprising: a light source unit for emitting randomly polarized light;
It has a light valve section for dimming incident light using polarized light, and a polarization conversion optical system for aligning random polarized light from the light source in one polarization direction, and has an optional optical path between the light source section and the light valve section. A first reflecting means capable of selectively reflecting polarized light and transmitting another polarized light, and a reflecting surface substantially parallel to the first reflecting means, the characteristics of which are at least polarized light transmitted through the first reflecting surface. It is characterized by comprising second reflecting means for reflecting light.

According to a fourth aspect of the present invention, there is provided a projection type image display apparatus comprising: a light source for emitting randomly polarized light; a light valve for dimming incident light without depending on polarization; A first reflecting unit that selectively reflects any polarized light and transmits another polarized light between the light source unit and the light valve unit; A reflecting surface is provided substantially parallel to the first reflecting means, and the second reflecting means is configured to reflect polarized light transmitted through at least the first reflecting surface. You.

According to a fifth aspect of the present invention, there is provided a projection type image display apparatus comprising: a light source unit for emitting randomly polarized light; a light valve unit for dimming incident light using polarized light; A first reflecting unit that selectively reflects any polarized light and transmits another polarized light between the light source unit and the light valve unit; A reflecting surface is provided substantially parallel to the first reflecting means, and the second reflecting means is configured to reflect polarized light transmitted through at least the first reflecting surface. You.

According to a sixth aspect of the present invention, there is provided a projection type image display apparatus comprising: a light source unit for emitting randomly polarized light; a light valve unit for dimming incident light using polarized light; A projection lens that enables enlarged projection of the image on the unit, and a polarization conversion optical system that aligns randomly polarized light from the light source in one polarization direction, and any polarized light between the light source unit and the light valve unit. A first reflecting means capable of selectively reflecting light and transmitting another polarized light, and a reflecting surface substantially parallel to the first reflecting means, the characteristic of which is to reflect polarized light transmitted at least through the first reflecting surface. The second to do
And a reflecting means.

According to the second, third, fifth and sixth aspects of the present invention, the light valve unit for dimming incident light by using the polarized light guides only light in an arbitrary polarization direction from the light source unit to the light valve. Incident-side polarization selecting means, and a light valve having a plurality of pixel openings and capable of controlling the polarization direction of light incident through the incident-side polarizing plate for each pixel in accordance with an input signal from outside,
An emission-side polarization selection unit that transmits only light in an arbitrary polarization direction among the light emitted from the light valve.

In the first and fourth inventions, the first reflecting means is a reflective polarizing plate, the transmission axis of which is arbitrarily set, and the second reflecting means is a total reflection mirror. Alternatively, the first reflection means is a reflection type polarizing plate, the transmission axis of which is set arbitrarily, and the second reflection means is arranged such that the transmission axis is orthogonal to the first reflection means. The present invention can also be configured to be a reflection type polarizing plate provided.

In the second, third, fifth and sixth aspects of the invention, the first reflection means is a reflection type polarizing plate, and the transmission axis of the first reflection means is the polarization direction of the polarized light used by the incident side polarization selection means. , The second reflecting means is a total reflection mirror, and the first reflecting means is a reflective polarizing plate, The axis is set so as to form an angle of about 45 degrees with respect to the polarization direction of the polarized light used by the incident-side polarization selection means, and the second reflection means is orthogonal to the first reflection means and its transmission axis. It can also be configured to be a reflection-type polarizing plate provided to perform the above. Further, the first reflection means is a reflection-type polarizing plate, the transmission axis of which is arbitrarily set, the second reflection means is constituted by a total reflection mirror, and the first and second reflection means are provided. A λ / 4 plate may be arranged on the exit side from the reflection surface or on the entrance side of the first reflection surface in addition thereto, and the first reflection means is a reflection type polarizing plate. The transmission axis is arbitrarily set, and the second reflection means is composed of a first reflection means and a reflection type polarizing plate provided so that the transmission axis is orthogonal to the first reflection means. Λ between the incident side of the reflecting surface and the outgoing side from the first and second reflecting surfaces.
It can also be configured that a / 4 plate is arranged.

More specifically, the first reflecting means is a polarizing beam splitter, and the second reflecting means is constituted by a total reflection mirror joined to a first reflecting surface. And a λ / 4 plate is disposed on the exit side from the second reflection surface or on the entrance side of the first reflection surface in addition to the above. A beam splitter, wherein the second reflection means is constituted by a total reflection mirror joined to the first reflection surface, and furthermore, the incident side of the first reflection surface and the first and second reflection surfaces. It can also be configured by arranging a λ / 2 plate on the exit side from the.

According to the first to sixth aspects of the present invention, the first reflecting means is a polarizing beam splitter, and the second reflecting means is a total reflection mirror joined to the first reflecting surface. Can be configured.

Further, in the first to sixth inventions, the second reflection means is arranged at an angle to the first reflection means. In particular, the optical axis reflected by the first reflecting means and the optical axis reflected by the second reflecting means are set so as to overlap on the illuminated part or on the light valve or in the vicinity thereof. It can also be configured.

In the first to sixth aspects of the present invention, only the incident light which enters a partial area of the incident light is the first reflecting means,
It can be characterized by passing through the second reflecting means.

[0026]

According to the present invention, even when randomly polarized light is emitted from the light source section, even if the light is linearly polarized light in one direction, the gaps between the reflecting surfaces are obtained by dividing the reflecting surfaces using polarized light. The amount of light incident on the surface to be illuminated and the light valve can be shifted by an amount proportional to the intensity of the luminance non-uniformity generated in the light source unit, and the luminance non-uniformity finally appearing by widening the distribution range. It is possible to improve color unevenness and provide a high-quality image with high uniformity.

(Embodiment 1) FIG. 1 is a schematic configuration diagram of Embodiment 1. In the illumination device 200 of this example, light emitted from the light source unit 201 along the system optical axis enters the return mirror unit 202 and reaches the illuminated unit 203.

The light source unit 201 includes a light source 204 and a reflector 205. Polarized light emitted from the light source and having a random polarization direction is reflected in one direction by the reflector 205 and enters the folding mirror unit 202.
The shape of the reflecting surface of the reflector 205 is parabolic,
An elliptical surface or a spherical surface can be used depending on the design of the optical system.

The folding mirror unit 202 is a parallel plane plate 208 having a reflection type polarizing plate 206 on the front surface and a total reflection mirror 207 on the back surface. Light source unit 201 incident here
The polarization direction vector component perpendicular to the transmission axis of the reflective polarizing plate 206 in the randomly polarized light from the light source is reflected, and reaches the illuminated portion 203 along the optical axis 209. The polarization direction vector component parallel to the transmission axis of the reflection type polarizing plate 206 passes through this, is reflected after entering the total reflection mirror 207 and enters the reflection type polarizing plate 206 again, but the polarization direction has not changed. To Penetrate. The light reflected by the total reflection mirror 207 in this manner also reaches the illuminated portion 203 along the optical axis 210.

In this manner, the light from the light source 204 is condensed on the illuminated portion 203, and at the same time, the light incident along the optical axis 209 and the light incident along the optical axis 210 are superimposed with a slight shift. It takes shape. Therefore, even if there is uneven brightness or color caused by the light source 204 or uneven brightness or color caused by non-uniform reflection characteristics of the reflector 205, a half-brightness light source image is formed on the illuminated portion 203 by shifting the position. Is spread widely and uneven components are distributed,
Brightness unevenness and color unevenness can be reduced to such an extent that they cannot be recognized. As described above, according to the first embodiment, it is possible to achieve illumination with less color unevenness and good uniformity.

In the above configuration, the distance between the reflective polarizing plate 206 and the total reflection mirror 207 is optimized mainly by the degree of unevenness and the degree of allowable unevenness. Since the light from the light source unit 201 is randomly polarized light, the reflection type polarizing plate 2 is used.
The transmission axis of 06 can be set arbitrarily. However, strictly speaking, since the total reflection mirror 207 has a high reflectance with respect to the S-polarized light, the reflection type polarizing plate 206 may set the transmission axis so as to reflect the P-polarized light with respect to its reflection surface. desirable.

Also, if the total reflection mirror 207 is a reflection type polarizing plate provided so that the transmission axis is orthogonal to the reflection type polarizing plate 206, the polarized light transmitted through the reflection type polarizing plate 206 is reflected here and reflected again. The light passes through the polarizing plate 206 and reaches the surface to be illuminated, and the same effects as those of the above configuration can be obtained.

According to the above configuration, the illumination position of the light reflected by the reflective polarizing plate 206 and the illumination position of the light reflected by the total reflection mirror 207 are slightly shifted. On the other hand, as shown in FIG. 2, a wedge-like optical path is formed between the reflection surface of the reflection type polarizing plate 206 and the reflection surface of the total reflection mirror 207 so that the optical axes of the respective reflection surfaces intersect on the surface to be illuminated. By supporting so that the interval is configured (here, the flat plate 212 having a wedge-shaped cross section), the problem can be solved.

Alternatively, as a means for improving the degree of deviation between the illumination position of the light reflected by the reflective polarizing plate 206 and the illumination position of the light reflected by the total reflection mirror 207, the folding mirror unit 202 is used as shown in FIG. By providing the reflection type polarizing plate 206 partially as shown in the above, it is also possible to adopt a configuration in which the peripheral brightness loss due to the displacement of the illumination position is suppressed. However, in this case, it is easy to configure, but it is needless to say that it is not as radical as the configuration of FIG.

Further, as shown in FIG. 4, the folded prism unit 21 is replaced with the folded mirror unit 202.
It can also be configured as 1. The folded prism unit 211 includes a triangular prism 213 and a parallel flat plate 214.
Are bonded between the triangular prism-shaped prism 213 and the plane parallel plate 214.
5 is provided, and a total reflection mirror 216 is provided on the other surface side of the parallel plane plate 214. I will not give details,
The same effect as the configuration using the folding mirror unit 202 shown above can be obtained.

(Embodiment 2) FIG. 5 is a schematic configuration diagram of Embodiment 2. The image display device 300 according to the present embodiment includes the light source unit 3
01, an illumination optical system 302 (integrator optical system), a folding mirror unit 303, and a light valve unit 304. The light source unit 301 includes a light source 305 that forms an arc through discharge between the electrodes to generate randomly polarized light, and a light source 3.
And a reflector 306 that reflects the light from the lens 05 in one direction on the axis of rotational symmetry. Light from the light source 301 enters the illumination optical system 302. In this example, an integrator optical system is used. The integrator optical system includes a light source side micro lens array (hereinafter, a first lens array 307) and a light valve side lens array (hereinafter, a second lens array 308).
As shown in FIG. 12, the first lens array 307 is configured by arranging a large number of rectangular micro lenses similar to a light valve opening described later.

The second lens array 308 is composed of the same number of micro lenses as the micro lenses forming the first lens array 307, and the micro lens images on the first lens array are superimposed on the light valve opening by this lens. Is formed. Thus, the illumination optical system 30
The light emitted from 2 is reflected by the turning mirror unit 303 and reaches the light valve unit 304 via the condenser lens 309. Folded mirror unit 3
03 is a parallel plane plate 313 provided with a reflective polarizing plate 311 on the front surface and a total reflection mirror 312 on the back surface. The polarization direction vector component perpendicular to the transmission axis of the reflective polarizing plate 311 in the randomly polarized light from the light source unit 301 incident thereon is reflected and reaches the light valve unit 304 along the optical axis 314. The polarization direction vector component parallel to the transmission axis of the reflective polarizing plate 311 is transmitted therethrough, and
After being incident, the light is reflected after 12 and enters the reflective polarizing plate 311 again, but passes through it again because the polarization direction has not changed. The light reflected by the total reflection mirror 312 in this way also travels along the optical axis 315 to the light valve unit 3.
It reaches 04.

The light valve unit 310 includes an incident side polarizing plate 316, a liquid crystal panel 317, and an outgoing side polarizing plate 31.
8, the incident side polarizing plate 316 transmits the linearly polarized light in the transmission axis direction, and absorbs the polarization direction in the direction orthogonal to this. Here, the transmission axis is arranged so as to form an angle of about 45 degrees with the transmission axis of the reflective polarizing plate 311. The light transmitted through the incident side polarizing plate 316 enters the liquid crystal panel 317. The liquid crystal panel 317 can change the polarization direction of the transmitted light for each of a large number of pixel openings by an external signal. Here, when each pixel is not driven, the polarization direction is rotated by 90 degrees, and when the pixel is driven, light is transmitted without a change in the polarization direction. Outgoing side polarizing plate 31
8 has a polarization characteristic in a direction orthogonal to the incident side polarizing plate 316. Accordingly, the polarization direction of the light of the pixel portion transmitted by the liquid crystal panel 317 with the polarization direction changed by 90 degrees is changed to the exit-side polarization plate 318.
Is transmitted here because it coincides with the transmission axis of. On the other hand, the light in the polarization direction of the pixel portion transmitted through the liquid crystal panel 317 without changing the polarization direction is absorbed here because it is orthogonal to the transmission axis of the emission-side polarizing plate 318.

In this manner, the light from the light source 305 is condensed on the light valve unit 303 and at the same time the optical axis 3
The light incident along 14 and the light incident along optical axis 315 are superimposed with a slight shift. Therefore, uneven brightness and uneven color generated in the light source 305, the reflector 306
Even if there is brightness unevenness or color unevenness due to the non-uniformity of the reflection characteristics of the light source unit, the light source image with half the brightness is shifted and formed on the light valve unit 303 to spread widely and unevenness components are distributed. Accordingly, it is possible to improve the brightness unevenness and the color unevenness to such an extent that they cannot be recognized. This is because the transmission axes of the reflection type polarizing plate 311 and the incident side polarizing plate 316 are approximately 45 degrees, and therefore, the incident side polarizing plate 316 has the optical axis 3.
Both the light on the optical axis 14 and the light on the optical axis 315 make use of a vector component which forms an angle of about 45 degrees. As described above, according to the second embodiment, it is possible to provide an image with less color unevenness and good uniformity.

In the above configuration, the interval between the reflective polarizing plate 311 and the total reflection mirror 312 is optimized mainly by the degree of occurrence of unevenness and the allowable degree of unevenness.

Even if the total reflection mirror 312 is a reflection type polarizing plate provided so that the transmission axis is orthogonal to the reflection type polarizing plate 311, the polarized light transmitted through the reflection type polarizing plate 311 is reflected here and is reflected again. The light passes through the mold polarizing plate 311 to reach the illuminated surface, and the same effect as the above configuration can be obtained.

According to the above configuration, the illumination position of the light reflected by the reflection type polarizing plate 311 and the illumination position of the light reflected by the total reflection mirror 312 are slightly shifted. On the other hand, in the same manner as in FIG. 2, the reflection type polarizing plate 3 is set so that the optical axes of the respective reflection surfaces intersect on the light valve unit 303.
The problem can be solved by supporting the reflection surface 11 and the reflection surface of the total reflection mirror 312 so that an optical interval is formed in a wedge shape.

Alternatively, as a means for improving the degree of deviation between the illumination position of the light reflected by the reflective polarizing plate 311 and the illumination position of the light reflected by the total reflection mirror 312, the folding mirror unit 303 is used as shown in FIG. In the same manner as described above, by partially providing the reflective polarizing plate 311, it is also possible to adopt a configuration in which the peripheral brightness loss due to the displacement of the illumination position is suppressed. However, in this case, it is easy to configure, but it is needless to say that the configuration is not as radical as the configuration shown in FIG.

Further, in the configuration of FIG. 5, a λ / 4 plate is disposed between the folding mirror unit 303 and the light valve unit 304 to convert the linearly polarized light separated by the folding mirror unit 303 into circularly polarized light. Thus, the light of the polarization direction reflected by the reflection type polarizing plate 311 and the light of the polarization direction reflected by the total reflection mirror 312 are converted into the light of the incident side polarization plate 3.
16 can be used equally, so that the reflective polarizing plate 311
And the incident side polarizing plate 316 can be arranged without any restriction on the transmission axis direction.

Further, as shown in FIG. 4, a folded prism unit 319 is used instead of the folded mirror unit 303.
It can also be configured as This folded prism unit 3
Reference numeral 19 denotes a triangular prism prism 320 and a parallel plane plate 321 joined to each other, and a polarizing beam splitter multilayer film 322 is provided between the triangular prism prism 320 and the parallel plane plate 321.
And a total reflection mirror 323 is provided on the other surface side of the parallel plane plate 321. Although not described in detail, the same effect as the configuration using the folding mirror unit 303 shown above can be obtained. At this time, since the transmission axis of the polarizing beam splitter multilayer film 322 becomes P-polarized light with respect to this plane, the incident side polarizing plate 316 is arranged so as to form an angle of 45 degrees with the polarization direction of this light. There is a need.

Also in the case of the folding prism unit 319, similarly to the folding mirror unit 303, the folding mirror unit 303 and the light valve unit 304
A λ / 4 plate is disposed between them, and the linearly polarized light separated by the folding prism unit 319 is converted into circularly polarized light, whereby the light in the polarization direction reflected by the polarization beam splitter multilayer film 322 and the total reflection mirror Since the light in the polarization direction reflected by the H.323 can be used evenly by the incident-side polarizing plate 316, it can be disposed without any restriction on the transmission axis direction between the polarizing beam splitter multilayer film 322 and the incident-side polarizing plate 316.

Here, needless to say, it is also possible to change the polarization direction to λ / 2 instead of λ / 4 and to adapt the polarization direction to the incident side polarizing plate 316.

(Embodiment 3) FIG. 6 is a schematic configuration diagram of Embodiment 3 of the present invention. Image display device 400 of this example
Denotes a light source unit 401, an illumination optical system 402 (a polarization direction conversion integrator optical system), a folding mirror unit 403,
And a light valve unit 404. The light source unit 401 includes a light source 405 that forms an arc by electric discharge between the electrodes to generate randomly polarized light, and a reflector 406 that reflects light from the light source 405 in one direction on its rotational symmetry axis.
Light from the light source unit 401 enters the illumination optical system 402.
In this example, an integrator optical system is used, and a microlens array on the light source side (hereinafter referred to as a first lens array 40).
7), a light valve side lens array (hereinafter referred to as a second lens array 408), and the first lens array 407 is configured by arranging a large number of rectangular microlenses similar to a light valve opening described later.

The second lens array 408 is composed of the same number of microlenses as the microlenses forming the first lens array 407, and this lens allows each microlens image on the first lens array to be polarized beam splitter array 409, It is formed on the light valve section 404 via the polarization direction conversion element 410 and the condenser lens 411. The polarizing beam splitter array 409 is a set of prisms having a parallelogram cross-sectional shape provided with a polarizing beam splitter multilayer film 412 parallel to the bonding surface as shown in the figure, and the light emitted from the second lens array 408 is The light is incident on the polarizing beam splitter multilayer film 412a at an incident angle of 45 degrees. Here, the P-polarized light is transmitted, and
Through 11, it reaches the return mirror unit 403. On the other hand, the S-polarized light is reflected here, similarly reflected by the polarizing beam splitter multilayer film 412b arranged in parallel next to the polarization beam splitter, and then incident on the polarization conversion element 410 to change the polarization direction by 90 degrees. Then, the light reaches the return mirror unit 403 via the condenser lens 411. In this manner, when the randomly polarized light from the light source unit 401 is emitted from the illumination optical system 402, it becomes linearly polarized light whose polarization direction is aligned in one direction.

The light emitted from the illumination optical system 402 is reflected by the return mirror unit 403,
Light valve section 404 via condenser lens 413
Leads to. The folding mirror unit 403 is a parallel flat plate 416 provided with a reflective polarizing plate 414 on the front surface and a total reflection mirror 415 on the back surface. Since the transmission axis of the reflective polarizing plate 414 is set at an angle of about 45 degrees with respect to the polarization direction of the light from the illumination optical system 402, the light reflected by the reflective polarizing plate 414 is incident light. A vector component (about half of the incident light) that forms an angle of 45 degrees with the polarization direction of the light is reflected here, passes through the reflective polarizer 414, is reflected by the total reflection mirror 415, and is again reflected by the reflective polarizer 4.
The polarization direction of the light passing through the illumination optical system 40 differs from that of the light reflected by the reflective polarizing plate 414 by 90 degrees.
Since the angle is approximately 45 degrees with respect to the polarization direction of the light from the light source 2, the vector component (the remaining half of the incident light) that forms an angle of −45 degrees with the polarization direction of the incident light from the illumination optical system 402 is Become.

The light reflected by the reflective polarizing plate 414 in this manner reaches the light valve unit 404 along the optical axis 417, and the light reflected by the total reflection mirror 415 reaches the light valve unit 404 along the optical axis 418.

The light valve unit 404 includes an incident side polarizing plate 419, a liquid crystal panel 420, and an outgoing side polarizing plate 42.
The incident side polarizing plate 419 transmits the linearly polarized light in the transmission axis direction and absorbs the polarization direction in a direction orthogonal to the transmission axis. Here, the transmission axis forms an angle of 45 degrees with the transmission axis of the reflective polarizing plate 414, and the illumination optical system 402
Are arranged so as to coincide with the polarization direction of the light emitted from. The light transmitted through the incident side polarizing plate 419 is transmitted to the liquid crystal panel 4.
20. The liquid crystal panel 420 can change the polarization direction of transmitted light for each of a large number of pixel openings by an external signal. Here, when each pixel is not driven, the polarization direction is rotated by 90 degrees, and when the pixel is driven, light is transmitted without a change in the polarization direction. The output side polarizing plate 421 has a polarization characteristic in a direction orthogonal to the input side polarizing plate 419. Accordingly, the polarization direction of the light of the pixel portion transmitted by the liquid crystal panel 420 after changing the polarization direction by 90 degrees coincides with the transmission axis of the emission-side polarizing plate 421, and is transmitted therethrough. On the other hand, the light in the polarization direction of the pixel portion transmitted by the liquid crystal panel 419 without changing the polarization direction is absorbed here because it is orthogonal to the transmission axis of the emission-side polarizing plate 421.

In this manner, the light from the light source 405 is condensed on the light valve unit 403, and
The light incident along 17 and the light incident along the optical axis 418 are superimposed with a slight shift. Accordingly, unevenness in brightness and color in the light source 405 and the reflector 406
Even if there is brightness unevenness or color unevenness due to the non-uniformity of the reflection characteristics of the light source image, the light source image with half the brightness is shifted and formed on the light valve unit 403 to spread widely and unevenness components are distributed. Accordingly, it is possible to improve the brightness unevenness and the color unevenness to such an extent that they cannot be recognized. As described above, according to the second embodiment, it is possible to provide an image with less color unevenness and good uniformity.

In the above configuration, the interval between the reflective polarizing plate 414 and the total reflection mirror 415 is optimized mainly by the degree of occurrence of unevenness and the allowable degree of unevenness.

Further, even if the total reflection mirror 415 is a reflection type polarizing plate provided so that the transmission axis is orthogonal to the reflection type polarizing plate 414, the polarized light transmitted through the reflection type polarizing plate 414 is reflected here and reflected again. The light passes through the mold polarizing plate 414 to reach the light valve unit 403, and the same effect as the above configuration can be obtained.

According to the above configuration, the illumination position of the light reflected by the reflection type polarizing plate 414 and the illumination position of the light reflected by the total reflection mirror 415 are slightly shifted. On the other hand, in the same manner as in FIG. 2, the reflection type polarizing plate 4 is arranged so that the optical axes of the respective reflection surfaces intersect on the light valve unit 403.
The problem can be solved by giving an instruction so that an optical interval is formed in a wedge-like manner between the reflection surface 14 and the reflection surface of the total reflection mirror 415.

As a means for improving the degree of deviation between the illumination position of the light reflected by the reflective polarizing plate 414 and the illumination position of the light reflected by the total reflection mirror 415, the folding mirror unit 403 shown in FIG. In the same manner as described above, by partially providing the reflective polarizing plate 414, it is possible to adopt a configuration in which the peripheral brightness loss due to the shift of the illumination position is suppressed. However, in this case, it is easy to configure, but it is needless to say that the configuration is not as radical as the configuration shown in FIG.

Further, in the configuration shown in FIG.
A λ / 4 plate is arranged between the second mirror unit 403 and the folding mirror unit 403 and between the folding mirror unit 403 and the light valve unit unit 404, and the linearly polarized light from the illumination optical system 402 is temporarily converted into circularly polarized light.
3, the polarization direction vector component perpendicular to the transmission direction of the reflective polarizing plate 414 is reflected, and reaches the light valve unit 404 via the λ / 4 plate along the optical axis 417. The polarization direction vector component parallel to the transmission axis of the reflection type polarizing plate 414 transmits here, and the total reflection mirror 41
5 After being incident, the light is reflected and re-enters the reflective polarizing plate 414, but passes there again because the polarization direction has not changed.
The light reflected by the total reflection mirror 415 in this manner also reaches the light valve unit 404 via the λ / 4 plate along the optical axis 418. At this time, the phase axis of the λ / 4 plate is set so as to coincide with the polarization direction when the circularly polarized light from the folding mirror unit 403 is emitted from the illumination optical system 402. With this configuration, the illumination optical system 40
2. The degree of freedom in setting the polarization axis between the reflection type polarizing plate 414 and the incident side polarizing plate 419 can be increased.

Further, similarly to FIG. 4, a folded prism unit 422 can be used instead of the folded mirror unit 403. This folded prism unit 422
Is formed by joining a triangular prism-shaped prism 423 and a parallel plane plate 424 to each other.
A polarizing beam splitter multilayer film 425 is provided between the mirror plates 24, and a total reflection mirror 426 is provided on the other surface of the parallel plane plate 424. Although not described in detail, the same effect as the configuration using the folding mirror unit 403 described above can be obtained. At this time, the transmission axis of the polarizing beam splitter multilayer film 425 becomes P-polarized light with respect to this plane. The transmission axis of the polarizing beam splitter multilayer film 425 needs to be arranged at an angle of 45 degrees with respect to the polarization direction of the polarized light emitted from the illumination optical system 402, and the incident side polarizing plate 419 is a polarizing beam splitter. It is necessary to arrange them so as to form an angle of 45 degrees with the transmission axis of the multilayer film 425.

However, this folded prism unit 4
22, the illumination optical system 402 and the folding prism unit 42 are similar to the folding mirror unit 403.
2, a λ / 4 plate is arranged between the folded prism unit 422 and the light valve unit 404, and the linearly polarized light from the illumination optical system 402 is once incident on the folded mirror unit 403 as circularly polarized light. The polarization direction vector component perpendicular to the transmission direction of the polarization beam splitter multilayer film 425 is reflected (S-polarized light), and reaches the light valve unit 404 via the λ / 4 plate along the optical axis 417. A polarization direction vector component parallel to the transmission axis of the polarization beam splitter multilayer film 425 transmits therethrough,
After being incident on the total reflection mirror 426, it is reflected and incident again on the polarizing beam splitter multilayer film 425, but transmits there again since the polarization direction has not changed. The light reflected by the total reflection mirror 426 in this manner also reaches the light valve unit 404 via the λ / 4 plate along the optical axis 418. At this time, the phase axis of the λ / 4 plate is set to a direction that converts the circularly polarized light from the folding mirror unit 403 so as to match the polarization direction when emitted from the illumination optical system 402. With this configuration, the illumination optical system 402, the polarizing beam splitter multilayer film 425, and the incident-side polarizing plate 41
It is possible to increase the degree of freedom in setting the polarization axis between the nine axes.

Here, the polarization direction is changed to λ / 2 instead of λ / 4, and the degree of freedom in setting the polarization axis between the illumination optical system 402, the polarization beam splitter multilayer film 425, and the incident side polarization plate 419 is also changed. It goes without saying that it is also possible to adapt to make it fit.

In this embodiment, the means for converting the randomly polarized light from the light source into the polarized light in one direction is constituted by a polarizing beam splitter array, a polarization conversion element, and a condenser lens. It is apparent that the present invention is not limited to the configuration, but can be applied if the same function can be performed.

(Fourth Embodiment) FIG. 7 is a schematic configuration diagram of a fourth embodiment.

The light source 501 and the illumination optical system 502
(Integrator optical system), folding mirror unit 5
03, a color separation optical system 504, a light valve unit 505, a color synthesis optical system 506, and a projection optical system 507. The light source unit 501 includes a light source 508 that forms an arc by electric discharge between the electrodes to generate randomly polarized light, and a reflector 50 that reflects light from the light source 508 in one direction on its rotational symmetry axis.
9 Light from the light source unit 508 is transmitted to the illumination optical system 50.
2 is incident. In this example, an integrator optical system is used and includes a light source side micro lens array (hereinafter, first lens array 510) and a light valve side lens array (hereinafter, second lens array 511). As described above, a large number of rectangular microlenses similar to the light valve opening described later are arranged.

The second lens array 511 is composed of the same number of micro lenses as the micro lenses forming the first lens array 510, and this lens causes each micro lens image on the first lens array to be superimposed on the light valve opening. Is formed. Light emitted from the illumination optical system 502 is reflected by the return mirror unit 503 and reaches the color separation optical system 504. Folded mirror unit 503
Denotes a reflective polarizing plate 512 on the front surface and a total reflection mirror 51 on the rear surface.
3 is a plane-parallel plate 514 including Of the randomly polarized light from the light source unit 501 incident thereon, the reflective polarizing plate 5
The polarization direction vector component perpendicular to the 12 transmission axes is reflected and reaches the color separation optical system 504 along the optical axis 515. The polarization direction vector component parallel to the transmission axis of the reflection type polarizing plate 512 passes through this, is reflected after entering the total reflection mirror 513, and enters the reflection type polarizing plate 512 again. To Penetrate. The light reflected by the total reflection mirror 512 in this manner is also reflected on the optical axis 5.
Along the line 16, the color separation optical system 504 is reached.

First, of the light incident on the blue reflecting dichroic mirror 517, the blue light is reflected here, further reflected by the reflecting mirror 518, and reaches the blue light valve unit 520 via the condenser lens 519. The green light and red light transmitted through the blue reflection dichroic mirror 517 are incident on the green reflection dichroic mirror 521, of which the green light reaches the green light valve unit 523 via the condenser lens 522. Red light is green reflection dichroic mirror 5
21 through the condenser lens 524 to the red light valve unit 525. Light valve part 50
5 is a blue light valve unit 52 as described above.
0, a green light valve unit 523 and a red light valve unit 525 are arranged for each color light. The light valve portion 505 is a liquid crystal panel using a polymer dispersed liquid crystal material. When no electric field is applied to the liquid crystal panel, the liquid crystal is in a random state. However, when an electric field is applied, the liquid crystal is aligned in the direction of the electric field, and the refractive index of the liquid crystal matches that of the polymer. The image is displayed by controlling to

The light transmitted through the light valve section 505 in this manner enters the color combining optical system 506. The color combining optical system 506 includes a green reflection dichroic mirror 526, a red reflection dichroic mirror 527, and a total reflection mirror 528. Light emitted from the blue light valve unit 520 passes through the green reflecting dichroic mirror 526 and the red reflecting dichroic mirror 527 and enters the projection optical system 507. The projection optical system 507 is set so that an image on each light valve can be enlarged and projected on a screen not shown. Green light valve unit 523
The light emitted from the light source is a green reflection dichroic mirror 526.
After that, the light is transmitted through the red reflecting dichroic mirror 527 and enters the projection optical system 507. The light emitted from the red light valve unit 525 is reflected by the total reflection mirror 52.
8. The light is reflected by the red reflection dichroic mirror 527 and enters the projection optical system 507. In this manner, the image on the light valve unit 505 is obtained as an enlarged image that is color-combined on a screen not shown.

As is clear from the above description, the light passing through the light valve 505 is composed of a component incident along the optical axis 515 and a component incident along the optical axis 516. In other words, the light from the light source 508 is condensed on the illuminated part 203, and at the same time, the light incident along the optical axis 515 and the optical axis 516
Are slightly superimposed and superimposed on each other.
At this time, the light sources viewed from the light valve unit 505 are arranged as if they were two positions apart from each other.
Even if there is brightness unevenness or color unevenness caused by the unevenness of the reflection characteristics of the reflector 509, the light source image with half the brightness is displaced even if there is uneven brightness or color unevenness.
5, the unevenness component spreads widely and distributes the unevenness component, so that the unevenness of the brightness and the unevenness of the color can be reduced to such an extent that it cannot be recognized. As described above, according to the fourth embodiment, it is possible to achieve illumination with less color unevenness and good uniformity.

In the above configuration, the interval between the reflective polarizing plate 512 and the total reflection mirror 513 is optimized mainly by the degree of occurrence of unevenness and the degree of allowable unevenness. Since the light from the light source unit 501 is randomly polarized light, the reflection type polarizing plate 5 is used.
12 transmission axes can be set arbitrarily. However, strictly speaking, since the total reflection mirror 513 has a high reflectance with respect to the S-polarized light, the reflection type polarizing plate 512 may set the transmission axis so as to reflect the P-polarized light with respect to its reflection surface. desirable.

Further, even if the total reflection mirror 513 is a reflection type polarizing plate provided so that the transmission axis is orthogonal to the reflection type polarizing plate 512, the polarized light transmitted through the reflection type polarizing plate 513 is reflected here and reflected again. The light passes through the polarizing plate 513 to reach the surface to be illuminated, and the same effect as the above configuration can be obtained.

According to the above configuration, the illumination position of the light reflected by the reflective polarizing plate 512 and the illumination position of the light reflected by the total reflection mirror 513 have a slight shift. On the other hand, as shown in FIG. 2, between the reflecting surface of the reflective polarizing plate 512 and the reflecting surface of the total reflection mirror 513 such that the optical axes of the respective reflecting surfaces intersect on the light valve portion 505 which is the surface to be illuminated. (Here, the flat plate 212 having a wedge-shaped cross section) can be solved.

Alternatively, as a means for improving the degree of deviation between the illumination position of the light reflected by the reflective polarizing plate 512 and the illumination position of the light reflected by the total reflection mirror 513, a folding mirror unit 514 is used as shown in FIG. By partially providing the reflective polarizing plate 512 as described above, it is also possible to adopt a configuration in which a peripheral brightness loss due to a shift in the illumination position is suppressed. However, in this case, it is easy to configure, but it is needless to say that it is not as radical as the configuration of FIG.

Further, similarly to FIG. 4, the folded mirror unit 503 can be replaced with a folded prism unit in the same manner as in the other embodiments.

In this embodiment, the image display device is a liquid crystal panel using a polymer-dispersed liquid crystal material. However, the image display device is not necessarily made of a liquid crystal material as described above, and can be applied to all image display devices that do not depend on polarization. .

(Fifth Embodiment) FIG. 8 is a schematic configuration diagram of a fifth embodiment.

Light source 601 and illumination optical system 602
(Integrator optical system), folding mirror unit 6
03, a color separation optical system 604, a light valve unit 605, a color synthesis optical system 606, and a projection optical system 607. The light source unit 601 includes a light source 608 that forms an arc by electric discharge between the electrodes to generate randomly polarized light, and a reflector 60 that reflects light from the light source 608 in one direction on its rotational symmetry axis.
9 The light from the light source unit 608 is
2 is incident. In this example, an integrator optical system is used. The integrator optical system includes a light source side microlens array (hereinafter, a first lens array 610) and a light valve side lens array (hereinafter, a second lens array 611). As described above, a large number of rectangular microlenses similar to the light valve opening described later are arranged. The second lens array 611 is composed of the same number of microlenses as the microlenses forming the first lens array 610. With this lens, each microlens image on the first lens array is superimposed on the light valve opening and formed. Is done. Light emitted from the illumination optical system 602 is reflected by the folding mirror unit 603 and reaches the color separation optical system 604. Folded mirror unit 60
3 is a reflective polarizing plate 612 on the front surface and a total reflection mirror 6 on the back surface.
13 is a plane-parallel plate 614 provided with the same. The polarization direction vector component perpendicular to the transmission axis of the reflective polarizing plate 612 of the randomly polarized light from the light source unit 601 incident thereon is reflected, and reaches the color separation optical system 604 along the optical axis 615. The polarization direction vector component parallel to the transmission axis of the reflection type polarizing plate 612 passes through this, is reflected after entering the total reflection mirror 613, and enters the reflection type polarizing plate 612 again. To Penetrate. The light reflected by the total reflection mirror 612 in this manner also has the optical axis 6
Along the line 16, the light reaches the color separation optical system 604.

First, of the light incident on the blue transmission dichroic mirror 617, the blue light transmits therethrough and is reflected by the reflection mirror 61.
The light is reflected at 8 and reaches the blue light valve unit 620 via the condenser lens 619. The green light and the red light reflected by the blue transmission dichroic mirror 617 enter the green reflection dichroic mirror 621, and the green light passes through the condenser lens 622 and the green light valve unit 6.
To 23. Red light is green reflection dichroic mirror 621
And enters the relay optical system 624. The red light incident here reaches the red light valve unit 630 via the incident side lens 625, the total reflection mirror 626, the intermediate lens 627, the total reflection mirror 628, and the condenser lens 629.

As described above, the light valve unit 605 is arranged for each color light as the blue light valve unit 620, the green light valve unit 623, and the red light valve unit 630. This light valve section 60
As shown in FIG. 13, reference numeral 5 comprises an incident-side polarizing plate, a liquid crystal panel, and an emitting-side polarizing plate, as shown in FIG. 13, and the incident-side polarizing plate transmits linearly polarized light in the transmission axis direction. Then, the direction of polarization orthogonal to this direction is absorbed. Here, the transmission axis is arranged so as to form an angle of 45 degrees with the transmission axis of the reflective polarizing plate. Light transmitted through the incident-side polarizing plate enters the liquid crystal panel. In this liquid crystal panel, the polarization direction of transmitted light can be changed for each of a large number of pixel openings by an external signal. Here, when each pixel is not driven, the polarization direction is rotated by 90 degrees, and when the pixel is driven, light is transmitted without a change in the polarization direction. The output-side polarizing plate has a polarization characteristic in a direction orthogonal to the input-side polarizing plate. Therefore, since the polarization direction of the light of the pixel portion transmitted by the liquid crystal panel after changing the polarization direction by 90 degrees coincides with the transmission axis of the exit-side polarizing plate, the light passes therethrough. On the other hand, the light in the polarization direction of the pixel portion transmitted through the liquid crystal panel without changing the polarization direction is absorbed here because it is orthogonal to the transmission axis of the exit-side polarizing plate.

The light transmitted through the light valve 605 in this manner enters the color combining optical system 606. The color combining optical system 606 is a color combining prism 633 formed by bonding four triangular prisms so that the blue reflecting dichroic mirror surface 631 and the red reflecting dichroic mirror surface 632 are arranged orthogonally. The light and red light are reflected and enter the projection optical system 607. The green light passes through the blue reflecting dichroic mirror surface 631 and the red reflecting dichroic mirror surface 632 and enters the projection optical system 607. In this way, the light valve unit 6 is
05 is enlarged and projected on a screen not shown.

As is clear from the above description, the light that has passed through the light valve section 605 is composed of a component incident along the optical axis 615 and a component incident along the optical axis 616. In other words, the light from the light source 608 is condensed on the light valve unit 605, and at the same time, the light incident along the optical axis 615 and the light incident along the optical axis 616 are slightly shifted and superimposed. At this time, the light sources viewed from the light valve unit 605 are arranged as if they were two positions apart from each other.
Even if there is luminance unevenness or color unevenness occurring at 08 or unevenness in the reflection characteristics of the reflector 609, a half-brightness light source image is formed on the light valve section 605 with a shifted position even if there is brightness unevenness or color unevenness. And the unevenness component is distributed, so that the unevenness of the brightness and the unevenness of the color can be improved to the extent that it cannot be recognized. Thus, Embodiment 5
According to this, it is possible to achieve illumination with less color unevenness and good uniformity.

In particular, in the optical system using the relay optical system in the above embodiment, the image of the color light that has passed through the relay optical system is inverted with respect to the other two color lights. If there is unevenness, the projected image appears as noticeable color unevenness. Therefore, the improvement effect of the present invention can be greatly expected.

In the above configuration, the interval between the reflective polarizing plate 612 and the total reflection mirror 613 is optimized mainly by the degree of occurrence of unevenness and the degree of allowable unevenness. Since the light from the light source unit 601 is randomly polarized light, the reflection type polarizing plate 6 is used.
12 transmission axes can be set arbitrarily. However, strictly speaking, since the total reflection mirror 613 has a high reflectance with respect to the S-polarized light, the reflection type polarizing plate 612 may set the transmission axis so as to reflect the P-polarized light with respect to its reflection surface. desirable.

Further, even if the total reflection mirror 613 is a reflection type polarizing plate provided so that the transmission axis is orthogonal to the reflection type polarizing plate 612, the polarized light transmitted through the reflection type polarizing plate 613 is reflected here and reflected again. The light passes through the polarizing plate 613 and reaches the surface to be illuminated, and the same effects as those of the above configuration can be obtained.

According to the above configuration, the illumination position of the light reflected by the reflective polarizing plate 612 and the illumination position of the light reflected by the total reflection mirror 613 are slightly shifted. On the other hand, as shown in FIG. 2, between the reflection surface of the reflection type polarizing plate 612 and the reflection surface of the total reflection mirror 613 such that the optical axes of the respective reflection surfaces intersect on the light valve portion 605 which is the illuminated surface. (Here, the flat plate 212 having a wedge-shaped cross section) can be solved.

Alternatively, as a means for improving the degree of deviation between the illumination position of the light reflected by the reflective polarizing plate 612 and the illumination position of the light reflected by the total reflection mirror 613, the folding mirror unit 614 shown in FIG. By providing the reflective polarizing plate 612 partially as described above, it is also possible to adopt a configuration in which a peripheral brightness loss due to a shift in the illumination position is suppressed. However, in this case, it is easy to configure, but it is needless to say that it is not as radical as the configuration of FIG.

Further, similarly to FIG. 4, a folded prism unit instead of the folded mirror unit 603 can be configured similarly to the other embodiments.

The folding mirror unit 603 is disposed immediately after the illumination optical system 603 here, but is not necessarily limited to this. As shown in FIG. 9, the total reflection mirrors 618 and 628 are folded mirror unit 603. Folding mirror units 634 and 6 having the same configuration as
Even with 35, the image quality can be improved for the blue and red optical paths by the same operation. Alternatively, it goes without saying that the same effect can be obtained even when the total reflection mirror 626 in the red light path is used as the folded mirror unit 635.

(Sixth Embodiment) FIG. 10 is a schematic configuration diagram of a sixth embodiment.

Light source section 701, illumination optical system 702 (polarization direction conversion integrator optical system), folding mirror unit 703, color separation optical system 704, light valve section 70
5, a color combining optical system 706 and a projection optical system 707. The light source unit 701 includes a light source 708 that forms an arc by electric discharge between the electrodes to generate randomly polarized light, and a reflector 709 that reflects light from the light source 708 in one direction on its rotational symmetry axis. Light from the light source unit 701 enters the illumination optical system 702. In this example, a polarization direction conversion integrator optical system is used, and a light source side micro lens array (hereinafter, a first lens array 710), a light valve side lens array (hereinafter, a second lens array 711), a polarization beam splitter array 712, Optical lens 713
The first lens array 710 is configured by arranging a large number of rectangular microlenses similar to a light valve opening described later, as shown in FIG.

The second lens array 711 is composed of the same number of micro lenses as the micro lenses forming the first lens array 710.
The light transmitted through the microlens passes through the polarizing beam splitter array 712 and the condenser lens, and the respective microlens images on the first lens array are superimposed and formed on the light valve opening. The polarizing beam splitter array 7
Numeral 12 is a set of parallelogram-shaped quadrangular prisms such that the polarizing beam splitter surfaces are arranged in parallel with an inclination of 45 degrees with respect to the incident light. The light emitted from the microlenses of the second lens array 711 is incident on the polarizing beam splitter array 712,
4a, the P-polarized light is transmitted through the polarization beam splitter surface 714a, but the S-polarized light is reflected here, and the polarization beam splitter surface 714a is reflected.
Polarizing beam splitter 714b arranged parallel to a
Incident on. Since this surface also has the same configuration, the incident S-polarized light is reflected again here and arranged on the exit side of the polarization beam splitter array 712 so that only the emission light from the polarization beam splitter 714b is selectively incident. The light enters the polarization conversion element 715.

Since the polarization direction of the light transmitted through the polarization conversion element 715 is changed by 90 degrees, the S-polarized light is
The light that is converted into polarized light and enters the return mirror unit 703 via the condenser lens 713 becomes P-polarized light.

As described above, the light emitted from the illumination optical system 702 is reflected by the return mirror unit 703 and reaches the color separation optical system 704. Folded mirror unit 70
3 is a reflective polarizing plate 716 on the front surface and a total reflection mirror 7 on the back surface.
17 is a plane-parallel plate 718 provided with the same. The polarization direction vector component perpendicular to the transmission axis of the reflective polarizing plate 716 out of the randomly polarized light from the light source unit 701 incident thereon is reflected and reaches the color separation optical system 704 along the optical axis 719.

The polarization direction vector component parallel to the transmission axis of the reflection type polarizing plate 716 transmits therethrough, and the total reflection mirror 717
After being incident, the light is reflected and re-enters the reflective polarizing plate 716, but passes through it again because the polarization direction has not changed. The light reflected by the total reflection mirror 717 in this manner also reaches the color separation optical system 704 along the optical axis 720. Since the transmission axis of the reflective polarizing plate 716 is set at an angle of about 45 degrees with respect to the polarization direction of the light from the illumination optical system 702, the light reflected by the reflective polarizing plate 716 is incident light. A vector component (approximately half of the incident light) that forms an angle of 45 degrees with the polarization direction of the light is reflected here, passes through the reflective polarizer 716, is reflected by the total reflection mirror 717, and is again reflected by the reflective polarizer 716. Since the transmitted light has a polarization direction different from that of the light reflected by the reflective polarizing plate 716 by 90 degrees and at an angle of approximately 45 degrees with respect to the polarization direction of the light from the illumination optical system 702, the illumination optical system 7
A vector component (approximately half of the incident light) that forms an angle of −45 degrees with the polarization direction of the incident light from 02.

The light incident on the color separation optical system 704 is incident on a blue transmission dichroic mirror 721, and the blue light is transmitted there, reflected by a total reflection mirror 722, passed through a condenser lens 723, and passed through a condenser lens 723.
Reaches 4. The green light and the red light reflected by the blue transmission dichroic mirror 721 enter the green reflection dichroic mirror 725, of which the green light reaches the green light valve unit 727 via the condenser lens 726. The red light passes through the green reflecting dichroic mirror 725 and enters the relay optical system 728. The red light incident here reaches the light valve unit for red 734 via the incident side lens 729, the total reflection mirror 730, the intermediate lens 731, the total reflection mirror 732, and the condenser lens 733.

As described above, the light valve section 705 is disposed for each color light as the blue light valve unit 724, the green light valve unit 727, and the red light valve unit 734. This light valve section 70
As shown in FIG. 13, reference numeral 5 comprises an incident-side polarizing plate, a liquid crystal panel, and an emitting-side polarizing plate, as shown in FIG. 13, and the incident-side polarizing plate transmits linearly polarized light in the transmission axis direction. Then, the direction of polarization orthogonal to this direction is absorbed. Here, the transmission axis forms an angle of 45 degrees with the transmission axis of the reflective polarizing plate, and is arranged so as to coincide with the polarization direction of the light emitted from the illumination optical system 702. Light transmitted through the incident-side polarizing plate enters the liquid crystal panel.

In this liquid crystal panel, the polarization direction of transmitted light can be changed for each of a large number of pixel openings by an external signal.
Here, when each pixel is not driven, the polarization direction is rotated by 90 degrees, and when the pixel is driven, light is transmitted without a change in the polarization direction. The output-side polarizing plate has a polarization characteristic in a direction orthogonal to the input-side polarizing plate. Therefore, since the polarization direction of the light of the pixel portion transmitted by the liquid crystal panel after changing the polarization direction by 90 degrees coincides with the transmission axis of the exit-side polarizing plate, the light passes therethrough.
On the other hand, the light in the polarization direction of the pixel portion transmitted through the liquid crystal panel without changing the polarization direction is absorbed here because it is orthogonal to the transmission axis of the emission-side polarizing plate.

The light transmitted through the light valve 705 in this manner enters the color combining optical system 706. The color combining optical system 706 is a color combining prism 737 formed by bonding four triangular prisms so that the blue reflecting dichroic mirror surface 735 and the red reflecting dichroic mirror surface 736 are arranged orthogonally. Light and red light are reflected and enter the projection optical system 707. The green light passes through the blue reflecting dichroic mirror surface 735 and the red reflecting dichroic mirror surface 736 and enters the projection optical system 707. In this manner, the light valve unit 7 is
05 is enlarged and projected on a screen not shown.

As is apparent from the above description, the light passing through the light valve 705 is composed of a component incident along the optical axis 719 and a component incident along the optical axis 720. In other words, the light from the light source 708 is condensed on the light valve unit 705, and at the same time, the light incident along the optical axis 719 and the light incident along the optical axis 720 are overlapped with a slight shift. At this time, the light sources viewed from the light valve unit 705 are arranged as if they were two positions apart from each other.
Even if there is brightness unevenness or color unevenness occurring at 08 or uneven brightness or color unevenness due to the non-uniformity of the reflection characteristics of the reflector 709, the light source image with half the brightness is formed on the light valve section 705 with the position shifted. And the unevenness component is distributed, so that the unevenness of the brightness and the unevenness of the color can be improved to the extent that it cannot be recognized. Thus, Embodiment 6
According to this, it is possible to achieve illumination with less color unevenness and good uniformity.

Particularly, in the optical system using the relay optical system in the above embodiment, the image of the color light passing through the relay optical system is inverted with respect to the other two color lights. If there is unevenness, the projected image appears as noticeable color unevenness. Therefore, the improvement effect of the present invention can be greatly expected.

In the above configuration, the interval between the reflective polarizing plate 716 and the total reflection mirror 717 is optimized mainly by the degree of occurrence of unevenness and the degree of allowable unevenness. Further, in this embodiment, the transmission axis of the reflective polarizing plate 716 is set to about 45 degrees with respect to the polarization direction of the incident light, but it goes without saying that there is no problem if this is set to -45 degrees.

Further, even when the total reflection mirror 717 is a reflection type polarizing plate provided so that the transmission axis is orthogonal to the reflection type polarizing plate 716, the polarized light transmitted through the reflection type polarizing plate 716 is reflected here and reflected again. The light passes through the mold polarizing plate 716 to reach the surface to be illuminated, and the same effect as the above configuration can be obtained.

According to the above configuration, the illumination position of the light reflected by the reflection type polarizing plate 716 and the illumination position of the light reflected by the total reflection mirror 717 are slightly shifted. On the other hand, as shown in FIG. 2, between the reflection surface of the reflection type polarizing plate 716 and the reflection surface of the total reflection mirror 717 such that the optical axis of each reflection surface intersects on the light valve portion 705 which is the illuminated surface. (Here, the flat plate 212 having a wedge-shaped cross section) can be solved.

Alternatively, as a means for improving the degree of deviation between the illumination position of the light reflected by the reflection type polarizing plate 716 and the illumination position of the light reflected by the total reflection mirror 717, a folding mirror unit 703 is used as shown in FIG. By providing the reflective polarizing plate 716 partially as described above, it is possible to adopt a configuration in which the peripheral brightness loss due to a shift in the illumination position is suppressed. However, in this case, it is easy to configure, but it is needless to say that it is not as radical as the configuration of FIG.

Further, similarly to FIG. 4, a folded prism unit instead of the folded mirror unit 703 can be configured in the same manner as the other embodiments. However, when the prism type is used, the polarization direction of light selectively reflected by the polarization beam splitter surface, which is a polarization splitting surface, is S-polarized light with respect to this surface. At this time, as described above, the angle between the polarization direction of the light emitted from the illumination optical system 702 and the S polarization direction of the polarization beam splitter surface is 45 degrees, and at the same time, approximately 45 degrees with the polarization direction used in the light valve unit. Need to be. Furthermore, since the mirrors of the color separation optical system 722 can increase the reflectance by using the S-polarized light with respect to the reflection surface, the mirrors convert the S-polarized light viewed from the reflection surface of the color separation optical system 722. On the other hand, it is required that the S-polarized light viewed from the polarizing beam splitter surface of the prism forms approximately 45 degrees. To simplify the configuration of the entire apparatus irrespective of the polarization direction between the units as described above, it is possible to cope with this by arranging an element for converting the polarization direction, such as a λ / 2 plate, as necessary.
Alternatively, by arranging a λ / 4 plate before and after the folded prism unit, the light incident on the polarization beam splitter surface can be converted into circularly polarized light and the output side can be converted into linearly polarized light again.

Although the folding mirror unit 703 is disposed immediately after the illumination optical system 702 in this case, the present invention is not limited to this. As shown in FIG. It is needless to say that the image quality of the blue and red optical paths can be improved by the same operation as the folded mirror unit having the above configuration.

In this embodiment, the means for converting the randomly polarized light from the light source into the polarized light in one direction is constituted by a polarizing beam splitter array, a polarization conversion element and a condenser lens. However, the present invention is not limited to this. It is apparent that the present invention is not limited to the configuration, but can be applied if the same function can be performed.

In the above-described embodiments using the image display apparatus for displaying an image by using polarized light, the description has been given of the normally white system in which white display is performed when there is no signal. Can adapt,
Further, it goes without saying that the present invention can be applied not only to a transmission type image display device but also to a reflection type.

[0108]

As described above, in the projection type image display apparatus of the present invention, the polarized light is utilized by using the polarized light regardless of whether the light source unit or the illumination optical system emits the randomly polarized light or the linearly polarized light in one direction. By dividing the reflection surfaces, the light to be illuminated and the light incident on the light valve can be shifted by an amount proportional to the gap between the reflection surfaces, so that the intensity of the brightness unevenness and color unevenness generated in the light source unit is weakened. By broadening the distribution range, the unevenness of luminance and color that finally appear can be improved, and a high-quality image with high uniformity can be provided while maintaining the size of the apparatus and without increasing the cost. This effect can be obtained irrespective of the form of the projection type image display device that constitutes the color synthesis and color separation in the projection type image display device. The configuration using an optical system is particularly useful because only a light source image of one color light is inverted and unevenness is easily noticeable.

[Brief description of the drawings]

FIG. 1 is a diagram showing a configuration of an embodiment of a lighting device of the present invention.

FIG. 2 is a configuration diagram showing another embodiment of the lighting device of the present invention.

FIG. 3 is a configuration diagram showing an embodiment of a folding mirror unit of the illumination device of the present invention.

FIG. 4 is a diagram showing a configuration of another embodiment of the lighting device of the present invention.

FIG. 5 is a diagram showing a configuration of another embodiment of the illumination device of the present invention.

FIG. 6 is a diagram showing a configuration of another embodiment of the illumination device of the present invention.

FIG. 7 is a diagram showing a configuration of an embodiment of the image display device of the present invention.

FIG. 8 is a diagram showing a configuration of another embodiment of the image display device of the present invention.

FIG. 9 is a diagram showing a configuration of another embodiment of the image display device of the present invention.

FIG. 10 is a diagram showing a configuration of another embodiment of the image display device of the present invention.

FIG. 11 is a diagram showing a basic configuration which is an example of a conventional projection type image display device.

FIG. 12 is an external view of an integrator optical system and a lens array on a light source side.

FIG. 13 is a configuration diagram of a light valve unit.

[Explanation of symbols]

100, 500, 600, 700 Projection image display devices 101, 201, 301, 401, 501, 601, 7
01 Light source unit 102, 302, 402, 502, 602, 703 Illumination optical system 103, 504, 604, 704 Color separation optical system 104, 624, 728 Relay optical system 105, 304, 404, 505, 605, 705 Light valve unit 106, 506, 606, 706 Color synthesis optical system 107, 507, 607, 707 Projection optical system 108, 204, 305, 405, 508, 608, 7
08 light source 109, 205, 306, 406, 509, 609, 7
09 Reflector 110, 307, 407, 510, 610, 710 First lens array 111, 308, 408, 511, 611, 711 Second lens array 112, 517, 617, 721 Blue transmission dichroic mirror 113, 120, 122, 207 , 216, 312, 3
23, 415, 426, 518, 528, 613, 6
18, 626, 628, 717, 722, 730, 7
32 Total reflection mirror 114, 117, 123, 309, 413, 519, 5
22, 524, 619, 622, 629, 723, 7
26,733 Condenser lens 115,520,620,724 Blue light valve unit 116,521,526,621,725 Green reflection dichroic mirror 118,523,727 Green light valve unit 119,625,729 Incident side lens 121, 627, 731 Intermediate lens 124, 525, 630, 734 Red light valve unit 125, 316, 419 Incident side polarizing plate 126, 317, 420 Liquid crystal panel 127, 318, 421 Outgoing side polarizing plate 128, 631, 735 Blue reflection dichroic Mirror surface 129, 632, 736 Red reflection dichroic mirror surface 130, 633, 737 Color combining prism 200 Illumination device 202, 303, 403, 503, 603, 634, 6
35, 703 Folded mirror unit 203 Illuminated part 206, 311, 414, 512, 612, 716 Reflective polarizing plate 208, 214, 313, 321, 424, 513, 6
14,718 Parallel plane plate 209,210,314,315,417,418,5
15, 516, 615, 616, 719, 720 Optical axis 212 Wedge shaped flat plate 211, 319, 422 Folded prism unit 213, 320, 423 Triangular prism shaped prism 215, 322, 412, 412a, 412b, 42
5, 714a, 714b Polarization beam splitter multilayer film 300, 400 Image display device 310 Light valve unit 409, 712 Polarization beam splitter array 410, 715 Polarization direction conversion element 411, 713 Condensing lens 527 Red reflection dichroic mirror

Claims (22)

[Claims] 1. A light source unit that emits randomly polarized light, and an illuminated unit, wherein an arbitrary polarized light can be selectively reflected between the light source unit and the illuminated unit and another polarized light is transmitted. 1
Characterized in that it comprises a reflecting means, and a second reflecting means, which is provided with a reflecting surface substantially parallel to the first reflecting means and reflects at least polarized light transmitted through the reflecting surface. apparatus. 2. A light source unit for emitting randomly polarized light, and a light valve unit for dimming incident light using polarized light, and an arbitrary polarized light is supplied between the light source unit and the light valve unit. A first reflecting means that can selectively reflect and transmit another polarized light, and a reflecting surface substantially parallel to the first reflecting means;
An image display device comprising: a second reflecting means for reflecting at least polarized light transmitted through the reflecting surface. 3. A light source unit that emits randomly polarized light, a light valve unit that modulates incident light using polarized light, and a polarization conversion optical system that aligns the randomly polarized light from the light source in one polarization direction. A first reflecting unit that selectively reflects any polarized light and transmits another polarized light between the light source unit and the light valve unit; and a reflecting surface substantially parallel to the first reflecting unit. An image display device comprising: a second reflecting means for reflecting at least polarized light transmitted through the reflecting surface. 4. A light source unit for emitting randomly polarized light, a light valve unit for dimming incident light without depending on polarization, and a projection lens for enlarging and projecting an image on the light valve unit. A first reflecting unit that selectively reflects arbitrary polarized light and transmits another polarized light between the light source unit and the light valve unit; and a reflecting surface substantially parallel to the first reflecting unit. A projection type image display device comprising a second reflection means for reflecting polarized light transmitted through the reflection surface. 5. A light source unit for emitting randomly polarized light, a light valve unit for dimming incident light using polarized light, and a projection lens for enlarging and projecting an image on the light valve unit. A first part which selectively reflects any polarized light between the light source part and the light valve part and transmits another polarized light;
And a second reflecting means, which comprises a reflecting surface substantially parallel to the first reflecting means and reflects at least polarized light transmitted through the reflecting surface. Type image display device. 6. A light source for emitting randomly polarized light, a light valve for dimming incident light using polarized light, a projection lens for enlarging and projecting an image on the light valve,
A polarization conversion optical system that aligns randomly polarized light from the light source in one polarization direction is provided, and any polarized light can be selectively reflected between the light source unit and the light valve unit and transmits other polarized light. It is characterized by comprising a first reflecting means, and a second reflecting means having a reflecting surface substantially parallel to the first reflecting means and reflecting at least polarized light transmitted through the reflecting surface. Projection image display device. 7. A light valve unit for dimming incident light by using the polarized light, an incident-side polarization selecting unit for guiding only light of an arbitrary polarization direction out of light from the light source unit to the light valve, and a plurality of pixels. A light valve having an opening and capable of controlling the polarization direction of light incident through the incident-side polarizing plate for each pixel in accordance with an input signal from the outside, and an arbitrary polarization direction of light emitted from the light valve. 7. The image display device or the projection type image display according to claim 2, further comprising: an output-side polarization selection unit that transmits only light. apparatus. 8. The apparatus according to claim 1, wherein said first reflecting means is a reflective polarizing plate, the transmission axis of which is arbitrarily set, and said second reflecting means is a total reflection mirror.
A lighting device, an image display device, or a projection-type image display device according to claim 4. 9. The first reflecting means is a reflective polarizing plate, the transmission axis of which is arbitrarily set, and the second reflecting means is arranged such that the transmission axis is orthogonal to the first reflecting means. 2. A reflection type polarizing plate provided.
A lighting device, an image display device, or a projection-type image display device according to claim 4. 10. The first reflection means is a reflection type polarizing plate, and its transmission axis is set to form an angle of about 45 degrees with respect to the polarization direction of the polarized light used by the incident side polarization selection means. 7. The image display device or the projection type image display device according to claim 2, wherein said second reflection means is a total reflection mirror. . 11. The first reflection means is a reflection type polarizing plate, and its transmission axis is set to form an angle of about 45 degrees with respect to the polarization direction of the polarized light used by the incident side polarization selection means. The second reflection means is a reflection type polarizing plate provided so that the transmission axis of the first reflection means is orthogonal to that of the first reflection means. Item 7. The image display device or the projection type image display device according to any one of Items 6. 12. The first reflection means is a reflection type polarizing plate, the transmission axis of which is arbitrarily set, the second reflection means is constituted by a total reflection mirror, and the first reflection means is a reflection type polarizing plate. The λ / 4 plate is arranged on the incident side of the reflecting surface and the emitting side from the first and second reflecting surfaces. 6
The image display device or the projection type image display device according to any one of the above. 13. The first reflection means is a reflection-type polarizing plate, the transmission axis of which is arbitrarily set, and the second reflection means is arranged such that the transmission axis is orthogonal to the first reflection means. The λ / 4 plate is constituted by a reflection type polarizing plate provided, and a λ / 4 plate is arranged at least on an emission side from the first and second reflection surfaces. An image display device or a projection-type image display device according to claim 5. 14. A λ / 4 also on the incident side of the first reflecting surface.
14. The image display device or the projection type image display device according to claim 13, wherein a plate is arranged. 15. The apparatus according to claim 1, wherein said first reflection means is a polarization beam splitter, and said second reflection means is a total reflection mirror bonded to a first reflection surface. 7. The lighting device, the image display device, or the projection-type image display device according to any one of 6. 16. The first reflection means is a polarizing beam splitter, and the second reflection means is constituted by a total reflection mirror joined to a first reflection surface, and at least the first and second reflection means are provided. Λ / 4 with the emission side from the second reflection surface
The image display device or the projection type image display device according to claim 2, wherein a plate is arranged. 17. A λ / 4 light source on the incident side of the first reflecting surface.
17. The image display device or the projection type image display device according to claim 16, wherein a plate is arranged. 18. The first reflection means is a polarization beam splitter, and the second reflection means is constituted by a total reflection mirror joined to a first reflection surface. 7. The image display device or the projection device according to claim 2, wherein a λ / 2 plate is arranged on an emission side from the second reflection surface. Type image display device. 19. The light receiving side of the first reflecting surface is also λ / 2.
The image display device or the projection type image display device according to claim 18, wherein a plate is arranged. 20. The method according to claim 19, further comprising:
The illumination device, the image display device, or the projection type image display device according to claim 1, wherein the reflection unit is disposed at an angle. 21. An optical axis reflected by said first reflecting means and an optical axis reflected by said second reflecting means are superimposed on an illuminated part, on a light valve, or in the vicinity thereof. The lighting device, the image display device, or the projection type image display device according to claim 1, wherein the setting is set. 22. The illumination according to claim 1, wherein only the incident light that enters a partial area of the incident light passes through the first reflecting means and the second reflecting means. Device or image display device or projection type image display device.