JP2002031842A - Projection type display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a projection type display device by which distortion correc tion of a picture on a screen and the correction of magnification factor are attained by making at least one or more reflection mirrors in an optical system non-planar partially or uniformly. SOLUTION: In the projection type display device having a light source, an optically modulating means, a projecting means to project the picture generated by the optically modulating means on the screen, the reflection mirror to make projected light emitted by the projecting means incident on the screen and the screen and making the center optical axis of the light projected by the projecting means obliquely incident on the screen, the reflection mirror is constituted of plural mirrors and at least one or more reflection mirrors are made non-planar.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a projection display device for displaying video images, computer images, and the like, and more particularly to a projection display device for projecting obliquely from the back of a screen using a liquid crystal light valve or the like.

[0002]

2. Description of the Related Art Recently, a display device (hereinafter, referred to as a light valve) using a transmission type or reflection type dot matrix liquid crystal or the like is used, and an image displayed on the light valve is enlarged and projected on a screen to form a large screen. Attention has been paid to an enlarged projection method to show. This is naturally limited in the image display by the cathode ray tube (CRT), and the size of the cathode ray tube itself is increased in order to enlarge the screen. In practice, the size of the cathode ray tube is limited to about 40 inches. This is in order to respond to a request to obtain an image.

On the other hand, in order to increase the area of the light valve itself, it is not easy to obtain a large liquid crystal display device having no defects in manufacturing, and even if it is obtained, it becomes extremely expensive.

[0004] For this reason, if an image displayed thereon is magnified and projected using a transmissive (or reflective) light valve, a powerful large screen is not affected by the size of the screen. It is possible to get.

Accordingly, a display type in which an optical system for enlarging and projecting using a light valve is housed in a cabinet, and the rear side is projected on a screen provided on the front of the cabinet so that an enlarged image can be viewed from the front of the cabinet. Has been provided.

A conventional rear projection type display device using a light valve of this type provides a transmissive liquid crystal light valve with illumination from a light source as disclosed in Japanese Utility Model Laid-Open No. 1-85778, for example. The image displayed on the bulb is enlarged by the projection lens, the optical path is changed by the reflection mirror, and the image is guided to the back of the screen.
In this way, the entire projection optical system is housed in the cabinet, can be moved to an arbitrary place, and the image on the screen can be viewed even in a bright room.

However, in the above-mentioned conventional display device using rear projection, a light beam transmitted through a light valve is converted into an optical path by a reflection mirror and guided to the rear surface of the screen. If projection is not performed, the image will be distorted due to trapezoidal distortion and the like, which greatly restricts the installation conditions of the reflection mirror. ), And therefore cannot be a rear-projection display device with a thin cabinet.

To solve this problem, an oblique projection system is conceivable. Generally, a trapezoidal distortion occurs in an image formed by a lens of a tilted object as shown by T. Scheimpflug in US Pat. As shown in FIG. 13, the inclined object surface 43 forms an image on the inclined image surface 45 by the lens 44. The relationship of the inclination is shown in FIG.
And the extension of the image plane 45 coincides with each other. Lens 4
Assuming that the point of intersection between the image plane 45 and the perpendicular to the optical axis Z of the image-side focal point f is g, the image ABCD on the square object surface shown in FIG. 14 is trapezoidal ABCD shown in FIG. And an image is formed on the image plane 45.

In order to eliminate the trapezoidal distortion, the first
6 the angle phi ₁ and the light valve 46 as shown in FIG first projection lens 47 and a second projection lens 49 and the screen 50 with respect to the _Z-axis, phi _2, arranged phi _3, phi ₄ only inclined To do. Here, an intersection line g between the plane parallel to the first projection lens 47 and the image plane 48 having a trapezoidal distortion passing through the image side focal point f1 of the first projection lens 47 and the object side of the second projection lens 49 The intersection line g 'between the plane passing through the focal point f2 and parallel to the second projection lens 49 and the image plane 48 having a trapezoidal distortion is made to coincide.

At this time, for example, the image of the square ABCD light valve 46 shown in FIG. 17 becomes an image ABCD having a trapezoidal distortion as shown in FIG. 19, an image ABCD without trapezoidal distortion shown in FIG. 19 is formed on the screen 50. Therefore, as shown in FIG. 12, if the projection optical system is folded by a first mirror 40 and a second mirror 41 and housed in a cabinet 38, a thin rear projection type display device is constituted. can do. In the figure, reference numeral 39 denotes a projection optical unit.

However, in the above-mentioned projection optical system, the focal length of the first projection lens 47 in FIG. 16 is reduced in order to eliminate trapezoidal distortion, and the aperture of the lens is reduced. For this purpose, it is necessary to illuminate the light valve 46 with light collected from the light source 51 by the condenser lens 52 as shown in FIG. At this time, as shown in FIG. 20, different angles θ are provided above and below the light valve 46.
₁ and θ ₂ , and the light valve 46
However, since the transmittance of the light changes depending on the incident angle, there is a problem that the brightness on the image on the screen 50 becomes uneven.

On the other hand, a conventional illuminating device used in this type of projection display device has a structure as shown in the sectional view of FIG.
A lamp 53 and a reflector 54 are provided.
The light beam emitted from the light source is reflected by the reflector 54 to become a light beam H, which is used as a light source to project an image on a screen.

However, in the above-mentioned prior art, the lamp 53
The light beam H emitted from the reflector 54 is reflected by the reflector 54 and emitted, and there is no reflected light at the center F of the reflector 54. Therefore, the distribution of the light beam having high parallelism is reduced as shown in FIG. And the center portion of the enlarged image projected on the screen is dark.

Further, the light K emitted from the end of the reflector 54 toward the periphery escapes as it is and cannot be used effectively.

On the other hand, a conventional rear projection type display device using this type of light valve is disclosed in, for example, Japanese Patent Application Laid-Open No. Hei 3-05125.
As can be seen in Japanese Patent Application Publication No. 1 (1999) -2005, an image displayed on a light valve illuminated by a light source is magnified and projected by a projection lens, an optical path is changed by a reflection mirror, and the image is guided from an oblique direction behind the screen. The reflecting mirror is a flat reflecting mirror 5 as shown in FIG.
5 is used.

However, when the flat reflecting mirror 55 is used, the projection lens or the reflecting mirror causes the image 56 on the screen 50 to be distorted as shown in FIG. 43, or the required magnification cannot be obtained. There is.

As a conventional transmission screen of this type, there is a structure shown in FIG. 50. FIG. 50A is a perspective view of the transmission screen, and FIG. 3 shows a cross section of the screen. The light image projected from the video projector 57 is focused on the front side by a micro prism array 58a formed on the back surface of the transmission screen 58. This micro prism array 5
The prism apex angle of each prism constituting 8a is formed at 52 ° as shown. The light image collected on the front side reaches the human eye 59, and the light image projected from the video projector 57 is recognized.

However, in the transmission screen 58 having the above structure, light leakage and ghost occurred.
That is, depending on the angle of the light incident on the prism array 58a, a phenomenon occurs in which a part of the light refracted by the prism and reaching the human eye 59 leaks in the transmission screen 58. Therefore, the image projected on the transmissive screen 58 became dark, making it difficult to visually recognize.

The mechanism by which a ghost occurs is considered as follows. That is, as shown in FIG. 51, the shielding sheet 6 is provided on the light incident surface side of the transmission screen 58.
0, the above-described prism array 58a is formed on the light incident surface side where the shielding sheet 60 is applied. Light incident from the direction indicated by the arrow is totally reflected by the emission surface 58b of the screen 58, and further refracted and bent by the prism array on the back side of the shielding sheet 60. The bent light reaches the human eye 59 via the emission surface 58b. Therefore, the part that should be dark because the light incident surface is covered with the black shielding sheet 60 looks bright to the human eye 59. Specifically, a portion that should be black originally looks red and bright and becomes very noticeable. This is considered that red is easily leaked because red is harder to bend due to wavelength dependence of refraction.

As a countermeasure to prevent such a ghost phenomenon, it is conceivable to form a black stripe 61 shown by oblique lines on the transmission screen 58 to block an optical path which causes light leakage. However, although it is possible to suppress the occurrence of ghost by such measures, it is not an essential measure for sealing the ghost, and it takes time and effort to form the black stripes 61 on the screen 58. There is.

An object of the present invention is to provide a display device of an oblique projection type in which a light valve in a projection display device is illuminated with parallel light whose incident angle is substantially constant in each part, so that brightness unevenness is small. .

Further, there is provided a projection type display device having an illumination device capable of making the distribution of parallel light beams emitted from a lamp of a light source and reflected by a reflector substantially uniform, thereby obtaining an image having substantially uniform brightness. The purpose is to:

Further, there is provided a display device capable of correcting distortion of an image on a screen and correcting an enlargement ratio by partially or uniformly making at least one reflecting mirror in an optical system non-planar. The purpose is to:

[0024] It is another object of the present invention to provide a display device having a transmissive screen capable of observing a high quality image without light leakage or ghost.

[0025]

That is, the present invention provides a light source, a light modulating means, a projecting means for projecting an image generated by the light modulating means on a screen, and a projection light emitted from the projecting means incident on the screen. A reflection mirror, and a screen, the projection display device in which the central optical axis of the projection light projected by the projection unit is obliquely incident on the screen, the reflection mirror is configured by a plurality of sheets, At least one reflecting mirror is made non-planar.

Further, there is provided an illuminating device having a lamp and a reflector, and a light transmitting optical element for substantially uniforming a light flux distribution obtained by reflection by the reflector in a space on the emission side of the reflector. It is characterized by the following.

Further, the optical element is characterized in that a portion limited to the center of one surface or both surfaces is formed as a concave surface or a convex surface.

Further, the present invention is characterized in that the thickness of a limited portion around the optical element is gradually reduced.

Further, the optical element has a conical shape.

Further, two convex conical optical elements are arranged as the conical optical element.

Further, two conical optical elements are used,
The first conical optical element is arranged in a convex shape, and the second conical optical element is arranged in a concave shape.

Further, one conical optical element having a double-sided convex shape is disposed as the conical optical element.

Further, one conical optical element having a convex surface on one side and a concave shape on the other side is arranged as the conical optical element.

Also, two conical optical elements are used,
It is characterized in that the first conical optical element has a convex shape on one surface and the other surface has a concave shape, and the second conical optical element has a convex shape.

Further, in a projection type display device having a transmission type screen in which a light image incident at an angle from the rear side is condensed on the front side by a micro prism array, each prism apex angle of the micro prism array is 40 degrees or more 50
The temperature is set to be less than or equal to the degree.

[0036] Further, the apparatus includes: a light modulating means; a projecting means for projecting an image generated by the light modulating means onto a screen; a reflecting mirror for projecting projected light emitted from the projecting means onto the screen; In a projection display device in which a final reflection mirror to be incident on a screen of a reflection mirror and the screen are arranged in parallel, the central optical axis of the projection light projected by the projection means has an incident angle α of 60 ° with respect to the screen. It is characterized by having a larger angle.

[0037]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in more detail with reference to the accompanying drawings.

FIG. 1 shows an embodiment of an oblique projection optical system arrangement according to the present invention, FIG. 2 shows an image of a light valve, FIG. 3 shows an intermediate image having trapezoidal distortion, and FIG. Each shows an image on a screen without trapezoidal distortion.

In FIG. 1, the first projection optical system has the first
The optical axis of the lens 3, the optical axis of the second lens 4, the optical axis of the second projection optical system 6, the normal of the light valve 2, and the screen 7
Are on the same plane.

In FIG. 1, a light source 1 uses a xenon lamp or a metal hydride lamp with a parabolic reflecting mirror, and a light valve 2 has a grid-like electrode arranged on a liquid crystal and a transmittance of each pixel. Is used so that it can be controlled.

The first lens 3 and the second lens 4 of the first projection optical system are tilted by an angle δ from each other, and the intersection of the image-side focal plane of the first lens 3 and the object-side focal plane of the second lens 4 is It is arranged to pass substantially on the Z axis. The intermediate image plane 5, the second projection optical system 6, and the screen 7 are arranged such that their extended surfaces intersect on the same straight line.

The light emitted from the light source 1 reaches the light valve 2 almost in parallel and illuminates it. Therefore, light rays enter the light valve 2 at substantially the same incident angle, and uniform brightness and contrast can be obtained on the entire surface of the light valve 2. The image of the light valve 2 is the first
An intermediate image having a trapezoidal distortion is formed on the intermediate image plane 5 by the lens 3 and the second lens 4. As shown in FIG. 5, the line of intersection between the intermediate image plane 11 and a plane parallel to the Z axis including the line of intersection between the image-side focal plane of the first lens 9 and the main plane of the second lens 10 is denoted by g. I do. As shown in FIG. 3, the intersection line g coincides with the intersection line g ′ between the plane passing through the object-side focal point of the second projection optical system 6 and parallel to the second projection optical system 6 and the intermediate image plane 5 as shown in FIG. The intermediate image ABCD distorted in a trapezoidal shape as shown in FIG.
As a result, an image ABCD without trapezoidal distortion is formed on the screen 7 as shown in FIG.

The first lens 3 and the second lens 4 of the first projection optical system in FIG. 1 are composed of a combination lens inclined by an angle φ as shown in FIG. 10, and can correct aberration. .

As the screen 7, a rear screen used for a rear projection television or the like can be used. This is to improve the light distribution characteristics by combining a lenticular lens and a Fresnel lens sheet with a resin substrate containing a diffusing agent. However, when the light is projected obliquely as in the present invention, the total reflection of the prism is used so that a part of the light projected on the screen 7 is enlarged and displayed in FIG. hand,
It is desirable to use a screen having a light distribution characteristic excellent for oblique projection by combining a sheet that directs the incident light beam in a direction substantially perpendicular to the front surface of the screen 7 and a sheet of a lenticular lens. Specific configurations of these will be described later.

FIG. 12 shows an embodiment of the configuration of the rear projection display device, and the projection optical unit 39 having the above-described configuration.
Is reflected by the first mirror 40 and the second mirror 41 and is obliquely incident on the screen 7, whereby the thickness D of the cabinet 38 can be reduced.

FIG. 6 shows an embodiment in which the second lens of the first projection optical system is a negative lens. By doing so, as shown in FIG. 6, the lens interval is set to f1 / cos φ ₁ −.
f2 / cos [phi ₂ and can be shortened, it is possible to compact the system. As in the first embodiment of the first projection optical system shown in FIG. 5, the first lens 13 of the first projection optical system
Including the intersection line between the image-side focal plane and the principal plane of the second lens 14
Assuming that the line of intersection between the plane parallel to the axis and the intermediate image plane 15 is g, the image is formed on the screen 7 as an image without trapezoidal distortion as in the above-described embodiment.

FIG. 7 shows the first projection optical system composed of two sets of two lenses that are not parallel to each other. By doing so, the inclination of each lens can be reduced, and a good image can be easily obtained. Can be That is, the first lens 17 and the second lens 18 of the first projection optical system are tilted by an angle δ _{1 from} each other, and the line of intersection of the image-side focal plane of the first lens 17 and the object-side focal plane of the second lens 18 is substantially Z. The third lens 20 and the fourth lens 21 of the first projection optical system are inclined by an angle δ _{2 with} respect to each other, and the image-side focal plane of the third lens 20 and the fourth lens 2
The first object-side focal plane is arranged so that the intersection line of the object-side focal plane is substantially on the Z axis. Further, the second intermediate image plane 22 and the second projection optical system 6
And the screen 7 are arranged such that the respective extended surfaces intersect on the same straight line.

The image of the light valve 16 in this case is the first
Is formed as an image with trapezoidal distortion on the first intermediate image plane 19 by the first lens 17 and the second lens 18 of the projection optical system of
The first intermediate image is formed by the third lens 20 and the fourth lens of the first projection optical system.
The lens 21 forms an image on the second intermediate image plane 22 as a second intermediate image having a trapezoidal distortion. As shown in FIG.
The image-side focal plane of the first lens 17 of the projection optical system and the main plane line of intersection of the second lens 18 and g _1. Z comprises the _{g 1}
A plane parallel to the axis, the line of intersection of the main plane of the third lens 20 of the first projection optical system and g _2. Third of first projection optical system
A plane including the image-side focal plane and the Z-axis intersects the point and g ₂ of the lens 20, a plane parallel to the Z-axis includes a line of intersection of the main plane of the fourth lens 21 of the second intermediate image plane 22 Let g be the intersection line.
Object-side focal plane of second projection optical system 6 and second intermediate image plane 22
When the intersecting lines g ′ and g are made to coincide with each other as shown in FIG. 3, the second intermediate image distorted in a trapezoidal shape as shown in FIG. Thus, the image is formed on the screen 7 as an image without trapezoidal distortion.

FIG. 8 shows another embodiment in which the first projection optical system is constituted by two sets of two lenses which are not parallel to each other.
By making the second lens 25 of the first projection optical system a negative lens, the lens interval is set to f1 / cosφ ₁ as shown in the figure.
-F2 / cos [phi ₂ and can be shortened, it is possible to compact the system. In the figure, 23 is a light valve,
24 is a first lens of the first projection system, 26 is a first intermediate image plane,
27 denotes a third lens, 28 denotes a fourth lens, and 29 denotes a second intermediate image plane.

FIG. 9 shows another embodiment in which the first projection optical system is composed of two sets of two lenses which are not parallel to each other. By making the fourth lens 35 of the first projection optical system a negative lens, the lens interval is set to f3 / co as shown in the figure.
Esufai ₃ can be shortened and -f4 / cosφ _4, can be made compact system. In the figure, reference numeral 30 denotes a light valve, 31 denotes a first lens of a first projection system, 32 denotes a second lens, 33 denotes a first intermediate image plane, 34 denotes a third lens, and 36 denotes a second intermediate image plane. .

Therefore, according to the above embodiments, an intermediate image having a trapezoidal distortion is formed by the first projection optical means,
In the oblique projection type display device for producing an image without trapezoidal distortion by the projection optical means, by using at least two lenses that are not parallel to each other as the first projection optical means,
The light modulating means can be illuminated with substantially parallel light, and unevenness in brightness and contrast can be reduced for the entire screen. Further, by configuring the first projection optical system with two or more sets of two lenses that are not parallel to each other, it is possible to provide a projection display device with less inclination of each lens, that is, less aberration and good imaging performance. .

Furthermore, when the rear projection display device is incorporated in a cabinet, the volume, particularly the depth, of the cabinet can be significantly reduced by oblique projection, and a compact display device can be provided.

According to the above-mentioned projection optical system, the light valve can be illuminated at a substantially constant incident angle, so that it is possible to provide an oblique projection display device with less unevenness in brightness. The resolution varies in the vertical direction as shown in the spot diagram of FIG.

Therefore, in the present invention, the above problem is solved by disposing a stop mechanism in the oblique projection optical system.

FIG. 22 is a layout diagram of an oblique projection optical system in which the above-mentioned stop mechanism is arranged, and FIG. 23 (A) to FIG.
(C) shows an example of the shape of the stop.

In FIG. 22, the optical axis of the first lens 80, the optical axis of the second lens 81, the optical axis of the third lens 82, the optical axis of the fourth lens 83, and the aperture mechanism of the first projection optical system. 84
, The optical axis of the second projection optical system 85, the light valve 8
The normal of 6 and the normal of screen 7 are on the same plane. Reference numeral 87 denotes a first intermediate image plane, and 88 denotes a second intermediate image plane.

In FIG. 22, the light source 1 is a xenon lamp or a metal hydride lamp with a parabolic reflector, and the light valve 86 has a grid-like electrode arranged on the liquid crystal so that the transmittance of each pixel can be controlled. The diaphragm mechanism 84
The shape shown in FIG. 23 is used.

The first lens 80 of the first projection optical system and the second lens 80
The lenses 81 are tilted from each other by an angle δ1, and the first lens 80
Are arranged so that the intersection line between the image-side focal plane and the object-side focal plane of the second lens 81 is on the Z-axis, and the aperture mechanism is located at the position where the focal planes of the first lens 80 and the second lens 81 intersect on the Z-axis. Are arranged, and the third lens 82 and the fourth lens 8 of the first projection optical system are arranged.
Numerals 3 are inclined by an angle δ2 from each other, and are arranged such that the intersection line between the image-side focal plane of the third lens 82 and the object-side focal plane of the fourth lens 83 is substantially on the Z axis. Further, the second intermediate image plane 88, the second projection optical system 85, and the screen 7 are arranged such that their extended surfaces intersect on the same line.

The light emitted from the light source 1 illuminates the light pulp 86 almost in parallel, and uniform brightness and contrast can be obtained on the entire surface of the light valve 86. The image of the light valve 86 passes through the first lens 80 and the second lens 81 of the first projection optical system and the aperture mechanism having the shape shown in FIG.
An image having a trapezoidal distortion is formed on the first intermediate image plane 87,
The second intermediate image 88 having a trapezoidal distortion on the second intermediate image plane 88 is formed by the third lens 82 and the fourth lens 83 of the first projection optical system.
The second intermediate image plane 88 is formed as an image without trapezoidal distortion by the second projection optical system 85 on the screen 7.
Image. At this time, the spot diagram on the screen 7 has less variation as shown in FIG. 24, and an image having a good resolution, a bright light amount, and a small unevenness can be obtained.

The diaphragm mechanism 84 shown in FIG. 23 (B) has a rhombic shape, and similarly to the above embodiment, the light flux emitted from the light source 1 shown in FIG. Is stopped by the aperture mechanism 84 to allow more light beams in the horizontal direction with good resolution to pass, so that an image with little loss of light amount can be obtained even if the aperture mechanism 84 is used to increase the resolution. In other words, even if the optical system shown in FIG. 22 has the shape shown in FIG. 23 (B), the spot diagram on the screen 7 has less variation as shown in FIG. Good, bright and less uneven images can be obtained.

The diaphragm mechanism 84 shown in FIG. 23 (C) is provided with a radius at each inner corner of the rhombus, so that an image having good resolution and a bright and less uneven image can be obtained similarly to the above embodiment. can get.

As described above, in the oblique projection optical system, even if the diaphragm is stopped down by the stop mechanism to obtain high resolution,
The resolution can be increased with little loss of brightness.

Further, when a rear projection type display device incorporated in a cabinet is used, the volume of the cabinet, particularly the depth, can be greatly reduced by oblique projection, so that it is compact, has good resolution, and has a low brightness loss. A small number of display devices can be provided.

The position of the aperture mechanism is not limited to the example shown in FIG. 22, but may be any position where the line of intersection between the two non-parallel positive lens focal planes intersects the Z axis. For example, the same effect as that shown in this embodiment can be obtained.

That is, the third lens 8 shown in FIG.
Even at the position where the intersection of the focal plane of the second lens 4 and the focal plane of the fourth lens 83 intersects the Z axis, the intersection of the focal plane of the first lens 3 and the second lens 4 shown in FIG. It may be a crossing position.

Further, the position where the line of intersection of the focal plane of the third lens 27 and the focal plane of the second lens 28 shown in FIG. 8 intersects the Z axis, or the focal point of the first lens 31 shown in FIG. The intersection line between the plane and the focal plane of the second lens 32 may intersect the Z axis.

Next, the lighting device will be described.

FIG. 25 shows a first example of the lighting device according to the present invention.
2 shows a main cross-sectional view of the embodiment.

That is, the lamp 53 is arranged at the focal position of the reflector 54 having a paraboloid of revolution, and the optical element 70 is arranged in front of the reflector 54. One surface of the optical element 70 has a concave surface 70a at the center, the periphery is perpendicular to the optical axis, and the other surface is perpendicular to the optical axis. Optical element 7
The zero concave surface 70a has a larger inclination toward the center.

Therefore, the light beam emitted from the lamp 53 is reflected by the reflector 54 and enters the optical element 70. Here, the light flux does not come out of the center F of the reflector 54. If the light emitting portion of the lamp 53 is very small, the light beam emitted from the lamp 53 is emitted as perfect parallel light by the parabolic reflector 54.
Has a size of several millimeters, the luminous flux emitted from the position shifted from the focal position of the reflector 54 is O
The light is emitted from the reflector 54 at an angle of about several degrees.

As described above, since the light beam has an angle component of 0 to several degrees, when the light beam is separated from the reflector 54 by a certain distance,
A light beam with a certain angle comes to the center. When the optical element 70 is placed here, the concave surface 7 of the optical element 70
The light flux is refracted by 0a, and the light flux of a certain angle component becomes parallel to the optical axis. Of the light beams incident on the optical element 70, those incident on the peripheral portion pass through the optical element 70 as it is. Therefore, the light beam passing through the optical element 70 has a parallel component from the center to the periphery.

With this arrangement, the illumination which has a low center portion as shown in FIG. 31 and has a light flux distribution in a hollow state can be sufficiently obtained at the center portion as shown in FIG. Lighting device.

FIG. 27 is a main sectional view showing a second embodiment, in which a lamp 53, a reflector 54 and an optical element 70 are arranged as in the first embodiment. The optical element 70 in this embodiment has a convex surface 70
b, the periphery of which is perpendicular to the optical axis and the other has a surface perpendicular to the optical axis. The slope of the convex surface 70b of the optical element 70 becomes larger toward the center.

Therefore, similarly to the first embodiment, a light beam having an angle component of 0 to several degrees near the center is refracted by the convex surface 70b of the optical element 70, and a light beam of a certain angle component is parallel to the optical axis. Become. Of the light beams incident on the optical element 70, those incident on the peripheral portion are
Go through 0. Therefore, the light beam passing through the optical element 70 has a parallel component from the center to the periphery.

As a result, similar to the first embodiment, the thirty first (31)
As shown in FIG. 26, an illumination device having a light flux distribution in a low center portion and a hollow state can be used as an illumination device in which a sufficient parallel light beam can be obtained even in the central portion as shown in FIG.

FIG. 28 is a main sectional view showing a third embodiment, in which a lamp 53, a reflector 54 and an optical element 70 are arranged as in the first embodiment. The optical element 70 in this embodiment has concave portions 70a, 7
0a, and the periphery has a plane perpendicular to the optical axis. The slopes of the concave portions 70a, 70a of the optical element 70 become larger as they approach the center.

Therefore, similarly to the first embodiment, a light beam having an angle component of 0 to several degrees near the center is refracted by the concave surface 70a of the optical element 70 and further refracted by the concave surface 70a on the opposite side. The luminous flux of the angle component becomes parallel to the optical axis. Of the light beams incident on the optical element 70, those incident on the peripheral portion pass through the optical element 70 as it is. Therefore, the light beam passing through the optical element 70 has a parallel component from the center to the periphery.

As a result, in the same manner as in the above embodiment, illumination having a light flux distribution with a low center and a hollow state as shown in FIG. 31, and a sufficiently parallel light flux can be obtained also at the center as shown in FIG. Such a lighting device can be provided.

FIG. 29 is a main sectional view showing a fourth embodiment, in which a lamp 53, a reflector 54 and an optical element 70 are arranged as in the first embodiment. Optical element 70
On one surface, the central portion is a concave surface 70a, from which the surface is perpendicular to the optical axis up to the same diameter as the diameter of the reflector 54, and further, the peripheral portion 70c is gradually thinner.
The other surface is perpendicular to the optical axis. Optical element 70
The inclination of the concave surface 70a increases toward the center.

Therefore, similarly to the first embodiment, a light beam having an angle component of 0 to several degrees near the center is refracted by the concave surface 70a of the optical element 70, and a light beam of a certain angle component is parallel to the optical axis. Become. Peripheral part 70c of optical element 70
Of the luminous flux incident on the optical axis, the component having an angle outside is directed parallel to the optical axis or slightly inward. The light incident on the plane perpendicular to the optical axis in the intermediate portion passes through the optical element 70 as it is. Therefore, the optical element 70
Has a component parallel or nearly parallel from the center to the periphery.

As a result, similar to the first embodiment, the third
Illumination having a light flux distribution in which the central portion is low as shown in FIG. 1 and which is in a hollow state can be used as an illumination device in which a sufficiently parallel light beam can be obtained even in the central portion as shown in FIG. In addition, the light of the portion K in FIG. 31, which is the peripheral light that could not be used until now, can be used.

Therefore, according to the above-described embodiment, the light beam emitted from the lamp is reflected by the reflector and is emitted with no parallel component near the center, but the above-described optical element is disposed in front of the reflector. A light beam having a sufficient parallel component also at the center can be obtained.

Further, as shown in the fourth embodiment, by using an optical element in which the thickness of the peripheral limited portion is reduced, the peripheral light which could not be used until now can be used. Become.

Therefore, when an image formed of liquid crystal or the like is projected on a screen using this illumination device, an enlarged projected image having substantially uniform brightness can be obtained.

FIGS. 32 to 37 show another embodiment of the optical element 70. FIG.

The embodiment shown in FIG.
The optical elements 70d and 70e are arranged so that their bottom faces face each other. For example, when the shape of the reflector 54 is a paraboloid, the light beam emitted from the lamp 53 is converted into a substantially parallel light beam by the reflector 54. And a second conical optical element 70e is disposed at a position where the second conical optical element 70e is turned upside down with respect to the optical axis of the light beam due to refraction. Becomes As a result, the light flux distribution shown in FIG. 32 is changed from the light flux distribution whose central portion is dark as in the conventional example shown in FIG. 31 by the two conical optical elements 70d and 70e shown in FIG.

In the embodiment shown in FIG. 33, of the two optical elements 70d and 70e, the optical element 70e on the exit side has a structure having a concave conical surface 70f. For this reason, for example, when the shape of the reflector 54 is a paraboloid, the light beam emitted from the lamp 53 is converted into a substantially parallel light beam by the parabolic reflector 54, enters the first conical optical element 70d, and is refracted. I do. The light flux due to refraction
At first, it comes near the optical axis where there is no parallel component.
By arranging the second conical optical element 70e at this position, a substantially parallel light flux B is obtained by refraction of the element 70e. Thereby, the light beam distribution of the conventional example in FIG. 31 becomes the light beam distribution shown in FIG. 37 by the conical optical elements 70d and 70e.

FIG. 34 shows two optical elements 70 of FIG.
d and 70e correspond to an integrated body, and FIG.
This is equivalent to the two optical elements 70d and 70e of FIG. 3 integrated, and in each case, the same operation as that of FIGS. 32 and 33 can be obtained.

FIG. 36 shows a case where the entrance surface of the conical optical element 70d on the entrance side is a concave curved surface 70g, and the conical optical element 70e on the exit side is the same as that in FIG.

According to the above embodiment, a parallel light beam having a substantially uniform distribution can be obtained by passing the light beam emitted from the lamp and reflected by the reflector through the conical optical element. Thus, when an image is projected on a screen using the substantially parallel light beam as a light source, an image having substantially uniform brightness is obtained.

Next, the reflection mirror will be described.

FIGS. 38 (A) and 38 (B) are cross-sectional views of a reflection mirror according to the present invention. When an image as shown in FIG. 39 is distorted, distortion is corrected in the direction of each arrow. It is.

As shown in FIG. 41, an example of a projection type display device according to the present invention includes a projection optical unit 39, a first reflection mirror 40a, a second reflection mirror 41a, and a third reflection mirror 42a. As shown in FIG. 1, the projection optical unit 39 includes a light source 1, a light valve 2, a first lens 3 of a first projection optical system, a second lens 4, and a second A projection type display device including the projection optical system 6 is used. For the operation of the projection optical unit 39, the description of FIG. 1 is cited.

As shown in FIG. 39, in the distortion of the image 56 on the screen 7 (FIG. 43) when the reflection mirror (generally referred to as 40a by a representative code) is flat,
In the case where the distortion correction in the direction of is required, the portion of the reflection mirror 40a corresponding to the portion requiring the distortion correction is made to have a partially convex surface as shown in FIG. Screen 56 as an image 56 'without distortion
Image. In the case where the distortion correction in the direction of is required, the portion of the reflection mirror 40a corresponding to the portion requiring the distortion correction is formed into a partially concave surface as shown in FIG. 38 (B). As shown, an image 56 'without distortion can be formed on the screen 7.

That is, the portion where the image 56 is desired to be enlarged is formed by making the reflecting mirror 40a a convex curved surface as shown in FIG. 38 (A), and the portion where the image 56 is desired to be reduced is shown in FIG. 38 (B).
The reflecting mirror 40a has a concave curved surface as shown in FIG.

In the projection type display device described in the above embodiment, when the image 56 on the screen 7 is smaller than the screen size without the necessary magnification, the reflection mirror 4
By forming the entire surface of Oa into a cylindrical shape having a convex curved surface as shown in FIG. 38 (A), an image 56 having no distortion as shown in FIG.
The image can be formed on the screen 7 as'. When the screen size becomes larger than the screen size, the entire surface of the reflection mirror 40a is formed into a concavely curved cylindrical shape as shown in FIG. 38 (B), so that an image 56 ′ without distortion as shown in FIG. Image.

The structure of the reflection mirror can be applied to one or more of the plurality of reflection mirrors 40a to 42a in the optical system.

As described above, according to this embodiment, in the projection type display device using the oblique projection optical system, the distortion of the image and the necessary enlargement ratio caused by the projection lens and the reflection mirror of the oblique projection optical system can be obtained. Even in the case where there is no mirror, the correction can be easily performed by at least one or more reflecting mirrors. At this time, the projection distance is partially changed, but the depth of focus of the projection optical system is deep, so that there is no practical problem of defocus.

Next, the screen will be described.

FIG. 45 is a perspective view showing a case where the transmission screen according to one embodiment of the present invention is applied to a rear projection type projector.

The light path of the light emitted from the projection optical unit 39 is converted by the reflection mirrors 72, 73, 74, and 75 and projected on the rear surface of the transmission screen 7. The transmission screen 7 is formed using polycarbonate (PC) or polymethyl methacrylate (PMMA) as a material. FIGS. 44 (A) and (B) are a perspective view and a partially enlarged cross section of the transmission screen 7. FIG. A micro prism array 7a is formed on the light incident surface of the screen 7, and a lenticular 7b is formed on the light exit surface.
Are formed. The micro prism array 7a has a triangular cross section, and each prism has an apex angle of 40 ° or more and 50 ° or less as described later.

In the transmission type screen 7 according to this embodiment, the prism apex angle is formed smaller than that of the conventional screen.
The amount of light leaking from the prism array 7a is reduced, and the loss of the amount of incident light is reduced. Therefore, light leakage and ghost do not occur unlike the related art. It was confirmed by the following analysis that the transmission screen 7 according to the present embodiment effectively suppressed the occurrence of light leakage and ghost. The result of this analysis will be described with reference to FIGS. 46 to 48.

FIG. 46 is a partially enlarged sectional view of a transmission screen used for this analysis, and this transmission screen is applied to the above-mentioned rear projection type projector. 44, the same parts as those in FIG. 44 are denoted by the same reference numerals. In FIG. 46, the light from the projection optical unit 39 reflected by the mirror 75 is refracted by the prism array 7a and emitted from the lenticular 7b. A part of the light reflected by the mirror 75 is leaked by the prism array 7a, and the leaked light is totally reflected by the light exit surface 7b. The totally reflected light passes through three or four prisms, is totally reflected by the prism that has entered beyond the critical angle α, and is emitted to the observation side via the lenticular 7b.

In such a transmission screen 7,
The results of calculating the ratio of the amount of light leakage at each point on the screen are shown in the graphs of FIGS. 47 and 48.
The horizontal axis of each graph indicates the screen position [mm].
Position 0 represents the vertical center point of the Fresnel lens 7a,
Other numerical values represent the distance moved from the center point in the up and down directions. The vertical axis of each graph indicates the leak rate [%] of what percentage of the light reflected from the mirror 75 leaks. In each graph, the plot on the straight line indicated by the solid line represents the analysis result when the prism apex angle of the prism array is 50 °, and the plot on the straight line indicated by the dotted line is the prism apex angle of 47 °, only the plot Represents the analysis result when the prism apex angle is 45 °. The light incident angle in each graph, that is, the angle at which the incident light is inclined with respect to the normal direction of the screen surface is 60 ° at the center.

FIG. 47 shows the calculation results when the size of the transmission screen 7 is 40 inches and the projection distance L is 1200 mm. FIG. 48 shows the calculation results when the projection distance L is 50 inches. The calculation result in the case of 1850 mm is shown. From each graph, it is understood that the light leakage rate decreases as the prism vertex angle decreases. That is, in the case of the 40-inch screen in FIG. 47, when the prism apex angle is 50 °, light leakage starts to occur at a position about 210 mm below the center point of the screen, and the light leakage rate increases as the distance from the center increases. And 300mm from the center
The light leak rate reaches about 24% at the lowered screen edge position. When the apex angle of the prism is 47 °, light leakage starts to occur at a position about 270 mm below the center point of the screen, and the light leakage rate becomes almost 10% at a screen end position 300 mm below. Also, when the prism apex angle is 45 °, only slight light leakage occurs at the screen edge position 300 mm below the center. In the case of a 40-inch screen, the length of the screen 7 in the vertical direction is 600 mm, and the measurement and evaluation may be performed within a range of 300 mm in each of the upper and lower directions from the center. Further, as can be understood from FIG. 45, since the light incident angle is smaller on the lower side of the screen 7, the light leakage rate is higher on the lower side from the center of the screen as shown in the above analysis result. . Therefore, it is sufficient to perform the evaluation at a screen position below the screen center.

Therefore, in the case of the 50-inch screen shown in FIG. 48, since the vertical length of the screen 7 is 750 mm, the analysis and evaluation may be performed within a range of 375 mm downward from the center of the screen. In this case, when the prism apex angle is 50 °, light leakage starts to occur at a position about 290 mm below the center, and the light leakage rate reaches about 22% at a screen end position 375 mm below the center. When the prism apex angle is 47 °, light leakage starts to occur at a screen position about 360 mm below the center, and 3 mm from the center.
The light leakage rate becomes about 5% at the screen edge position lowered by 75 mm. When the prism apex angle is 45 °, light leakage does not occur.

As described above, as the prism apex angle of the prism array decreases from 50 °, the light leakage rate gradually decreases. When the prism apex angle is reduced to 45 °, 40
Light leakage hardly occurs on an inch or 50 inch screen. When the prism apex angle is 50 °, the light leakage rate is 24% at the screen edge position of a 40-inch screen.
It is considered that there is no problem in practical use if the leakage is at this level. However, when the vertex angle of the prism is small, the vertex angle portion is likely to be chipped and the moldability during resin molding is deteriorated. Therefore, each prism apex angle of the prism array 7a is set to 4
Forming in the range of 0 ° or more and 50 ° or less can effectively prevent light leakage and ghost.

Also, the projection optical unit 3 according to the present embodiment
A xenon lamp having high directivity is used as the light source 9. For this reason, as shown in FIG. 49, by removing the optical path of the leaked light from the visual field A of the human eye 59, the ghost cannot be visually recognized by the human.

As described above, according to this embodiment, the apex angle of each prism of the micro prism array is set to be not less than 40 degrees and not more than 50 degrees, and since the apex angle of the prism is small, the amount of light leaking from the prism array can be reduced. And the loss of the incident light quantity is reduced. Therefore, according to this transmission screen, ghost and light leakage are eliminated, and a bright high-quality image can be obtained.

On the other hand, a conventional rear projection display device using this kind of light valve has an incident angle α with respect to the screen 7 as shown in FIG. 52 in order to reduce the thickness. At this time, the incident angle α is 60 ° or less. The final reflection mirror 9 for making the projection light 90 incident on the screen 7
1 was arranged parallel to the screen 7.

However, in the above-mentioned conventional display device of the rear projection type, since the incident angle α to the screen 7 is 60 ° or less, an overlapping portion is formed in the height direction of the screen 7 and the final reflection mirror 91. As shown in FIG. 53, external light 92 generated by a room lamp or the like is incident at an incident angle θ ₁
Is 60 °, the emission angle θ ₃ ′ is about 15.43 °, the light passes through the screen 7 and is reflected by the reflection mirror 91, and as shown in FIG. 54, the incident angle θ of about 15.43 °
Incident on the screen at the _{3 ',} in order to transmit the screen emission angle theta ₁ is turned 60 °, the shaded portion of the screen surface 7 as shown in FIG. 55 is or glowing whitish, causing decrease contrast There's a problem.

In order to cope with the above point, as shown in FIG. 56, by making the incident angle α to the screen 7 at an angle of 60 ° or more, the height of the screen 7 and the final reflection mirror 91 in the height direction is increased. Since the overlapping portion is reduced, as shown in FIG. 53, the external light 92 has an incident angle θ ₁ of 60, for example.
In the case of °, even when the light passes through the screen 7 and is reflected by the reflection mirror 91 at an emission angle θ ₃ ′ of about 15.43 °, it does not enter the screen 7.

Therefore, according to the above embodiment, in the projection type display device using the oblique projection optical system, the whitish portion of the screen due to the external light can be reduced, so that the decrease in contrast is reduced and a high-contrast image can be obtained. .

A projection type display device in which a screen of uniform brightness is obtained without unevenness in brightness, and no image distortion or light leakage,
It is particularly suitable for use in cabinet type display devices.

[Brief description of the drawings]

FIG. 1 is a layout view of an oblique projection optical system according to the present invention.

FIG. 2 is an explanatory view of a light valve in FIG. 1;

FIG. 3 is an explanatory diagram of an intermediate image in FIG. 1;

FIG. 4 is an explanatory diagram of image formation on a screen in FIG. 1;

FIG. 5 is an arrangement diagram of an optical system according to an embodiment when the first projection optical system according to the present invention is configured by a positive lens.

FIG. 6 is an arrangement diagram of an optical system according to an embodiment when the first projection optical system according to the present invention includes a positive lens and a negative lens.

FIG. 7 is an optical system layout diagram of an embodiment of a first projection optical system using a positive lens using two sets of two lenses that are not parallel to each other according to the present invention.

FIG. 8 is an optical system layout diagram of an embodiment of a first projection optical system using two non-parallel lenses in a first projection optical system according to the present invention;

FIG. 9 is an optical system layout diagram of a second embodiment of a first projection optical system using two sets of two lenses that are not parallel to each other and a positive lens and a negative lens according to the present invention.

FIG. 10 is a sectional view of an embodiment of a lens used in the present invention.

FIG. 11 is a partially enlarged view of a cross section of a screen due to total reflection of a prism used in the present invention.

FIG. 12 is a cross-sectional view of a configuration example of a rear projection display device using an oblique projection optical system according to the present invention.

FIG. 13 is an explanatory diagram of image formation on an inclined object surface.

FIG. 14 is an explanatory view of the object surface of FIG. 13;

FIG. 15 is an explanatory diagram of an image formed on the image plane in FIG. 13;

FIG. 16 is a sectional view of an oblique projection optical system.

FIG. 17 is an explanatory view of the light valve in FIG. 16;

FIG. 18 is an explanatory diagram of an image plane having a trapezoidal distortion in FIG. 16;

FIG. 19 is an explanatory diagram of image formation on the screen in FIG. 16;

FIG. 20 is an optical path diagram of an oblique projection optical system including an illumination system.

FIG. 21 is a spot diagram in a conventional projection optical system.

FIG. 22 is a sectional view of a projection optical system provided with an aperture mechanism according to the present invention.

FIGS. 23A to 23C are explanatory diagrams showing examples of the shape of a diaphragm mechanism.

FIG. 24 is a spot diagram on a screen when the aperture mechanism according to the present invention is used.

FIG. 25 is a cross-sectional view of an illumination optical device of the projection display device of the present invention.

FIG. 26 is a parallel light flux distribution diagram of the illumination optical device of the present invention.

FIG. 27 is a cross-sectional view of an illumination optical device of a projection display according to another embodiment of the present invention.

FIG. 28 is a cross-sectional view of an illumination optical device of a projection display according to still another embodiment of the present invention.

FIG. 29 is a cross-sectional view of an illumination optical device of a projection display according to still another embodiment of the present invention.

FIG. 30 is a cross-sectional view of an illumination optical device of a conventional projection display device.

FIG. 31 is a parallel luminous flux distribution diagram of an illumination optical device of a conventional projection display device.

FIG. 32 is a sectional view showing a modification of the optical element.

FIG. 33 is a sectional view showing a modification of the optical element.

FIG. 34 is a sectional view showing a modification of the optical element.

FIG. 35 is a sectional view showing a modification of the optical element.

FIG. 36 is a sectional view showing a modification of the optical element.

FIG. 37 is a diagram showing a parallel light beam distribution according to the embodiment shown in FIGS. 32 to 36;

38A and 38B are cross-sectional views showing an embodiment of the reflection mirror of the present invention.

FIG. 39 is an explanatory view showing the direction of operation according to the present invention.

FIG. 40 is an explanatory diagram of image formation on a screen according to the present invention.

FIG. 41 is a cross-sectional view of a configuration example of a projection display device using the reflection mirror.

FIG. 42 is a sectional view of a final reflection mirror according to the prior art.

FIG. 43 is an explanatory diagram of image formation on a screen according to FIG. 42;

FIGS. 44A and 44B are a partial perspective view and a sectional view showing the structure of a transmission screen according to the present invention.

FIG. 45 is a perspective view of a rear projection type projector to which the transmission screen according to the present embodiment is applied.

FIG. 46 is a sectional view of a screen used for analysis for confirming the effectiveness of the transmission screen according to the present embodiment.

47 is a graph showing the light leakage rate at each position of the screen when the transmission screen of FIG. 46 is applied to a 40-inch screen.

FIG. 48 is a graph showing a light leakage rate at each position of the screen when the transmission screen of FIG. 46 is applied to a 50-inch screen.

FIG. 49 is an explanatory diagram showing that a ghost is prevented from being visually recognized by a light source having high directivity.

FIGS. 50A and 50B are diagrams showing a conventional transmission screen.

FIG. 51 is an explanatory diagram of a mechanism in which a ghost occurs.

FIG. 52 is a sectional view of a final reflection mirror according to the prior art.

FIG. 53 is a state diagram when external light passes through the screen.

FIG. 54 is a state diagram when external light reflected by a final reflection mirror passes through a screen.

FIG. 55 is an explanatory view of a screen according to the related art.

FIG. 56 is an embodiment of the reflection mirror of the present invention, and is a cross-sectional view according to the embodiment.

[Explanation of symbols]

 Reference Signs List 1 light source 2 light valve (light modulation means) 7 screen

────────────────────────────────────────────────── ───

[Procedure amendment]

[Submission date] June 15, 2001 (2001.6.1)
5)

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] Claims

[Correction method] Change

[Correction contents]

[Claims]

[Procedure amendment 2]

[Document name to be amended] Statement

[Correction target item name] 0025

[Correction method] Change

[Correction contents]

[0025]

In order to achieve the above object, the present invention provides a light source, a light modulating means, a projecting means for projecting an image generated by the light modulating means on a screen, and a light emitting means for projecting an image. At least one or more reflecting mirrors for causing the projection light to be incident on the screen, and a screen,
In a projection display device in which a central optical axis of projection light projected by the projection unit is obliquely incident on the screen, at least one of the reflection mirrors is formed as a non-planar surface having a convex curved surface and a concave curved surface. It is characterized by the following. A light source, a light modulating means, a projecting means for projecting an image generated by the light modulating means onto a screen, a reflecting mirror for projecting projected light emitted from the projecting means onto the screen, and a screen. In a projection display device in which a central optical axis of projection light projected by a projection unit is obliquely incident on the screen, the reflection mirror includes a plurality of reflection mirrors, and at least one reflection mirror has a convex curved surface. It is characterized in that it is made non-planar and at least one or more other reflecting mirrors are made non-planar having a concave curved surface.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme court ゛ (Reference) H04N 5/74 H04N 5/74 F (31) Priority claim number Japanese Patent Application No. 3-233395 (32) Priority date September 12, 1991 (September 12, 1991) (33) Priority claim country Japan (JP) (31) Priority claim number Japanese Patent Application No. 3-236336 (32) Priority date September 17, 1991 (1991.17.17) (33) Priority claiming country Japan (JP) (31) Priority claim number Japanese Patent Application No. 3-281500 (32) Priority date October 28, 1991 (1991.28.1991) (33) Priority claim country Japan (JP) (31) Priority claim number Japanese Patent Application No. 4-35231 (32) Priority date February 21, 1992 (199.2.2.21) (33) Priority claim country Japan (JP) (72) Inventor Masaki Ishikawa 3-5-5 Yamato, Suwa-shi, Nagano Seiko Epson Corporation (72) Inventor Tanimoto Hitoshi Nagano Prefecture Suwa Yamato Third Street No. 3 No. 5 Seiko Epson Corporation over the F-term (reference) 2H088 EA13 EA16 EA19 HA10 HA21 HA28 2H091 FA14X FA14Z FA41X FD01 FD12 5C058 BA23 BA27 EA11 EA13

Claims (12)

[Claims] A light source; a light modulating means; a projecting means for projecting an image generated by the light modulating means onto a screen; a reflecting mirror for projecting projected light emitted from the projecting means onto the screen; and a screen. Then, in a projection display device in which the central optical axis of the projection light projected by the projection means is obliquely incident on the screen, the reflection mirror is constituted by a plurality of reflection mirrors, and at least one or more reflection mirrors are not provided. A projection display device characterized by being made flat. 2. An illuminating device comprising a lamp and a reflector, wherein a light-transmitting optical element is disposed in a space on an emission side of the reflector for substantially uniforming a light flux distribution obtained by reflection by the reflector. Projection display device. 3. The optical element according to claim 2, wherein a portion limited to the center of one surface or both surfaces is formed as a concave surface or a convex surface.
The projection type display device according to the above. 4. A projection display device having an illuminating device according to claim 2, wherein the thickness of a limited portion around the optical element is gradually reduced. 5. The projection display device according to claim 2, wherein said optical element has a conical shape. 6. The projection display according to claim 5, wherein two convex conical optical elements are arranged as said conical optical elements. 7. The projection type according to claim 5, wherein two conical optical elements are used, the first conical optical element is arranged in a convex shape, and the second conical optical element is arranged in a concave shape. Display device. 8. The projection type display device according to claim 5, wherein one conical optical element having a double-sided convex shape is disposed as said conical optical element. 9. The projection type display device according to claim 5, wherein one conical optical element having a convex surface on one side and a concave surface on the other side is disposed as said conical optical element. 10. The method according to claim 1, wherein two conical optical elements are used, and the first conical optical element has a convex surface on one side and a concave surface on the other side.
6. The projection display device according to claim 5, wherein the second conical optical element is arranged in a convex shape. 11. A projection display device having a transmission screen in which a light image incident at an angle from the rear side is converged on the front side by a micro prism array, wherein each prism apex angle of said micro prism array is A projection display device having a transmissive screen, wherein the projection display device is set at 40 degrees or more and 50 degrees or less. 12. A light modulating means, a projecting means for projecting an image generated by the light modulating means on a screen, a reflecting mirror for projecting projected light emitted from the projecting means onto the screen, and a screen. In a projection display device in which a final reflection mirror to be incident on a screen of a reflection mirror and the screen are arranged in parallel, the central optical axis of the projection light projected by the projection means has an incident angle α of 60 ° with respect to the screen. A projection display device having a larger angle.