JPH11125865A - Projecting device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a projecting device by which the correction of the arrangement (interval) and angle error of a catoptric element is remarkably improved and where the deterioration of an image is not caused by efficiently preventing the occurrence of stray light. SOLUTION: All catoptric elements (first mirror 2, second mirror unit 3 and third mirror unit 4) constituting a projection image formation optical system are arranged at a housing 1, and are made into an integral structure. A hole to observe the angle of the catoptric element is formed at the housing 1-b or an attaching member 4-2'. An adjustment mechanism to execute tilt and shift adjustment by centering the reference apex of the catoptric element 2 is provided. Also, light-shielding plates 1 and 6 and the light-shielding plates 2 and 7 having a shape to cover an effective luminous flux are arranged in the vicinity of a diaphragm 5.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a light source device, an illumination optical system for irradiating light from a light source to a light valve for forming an image, and a screen for displaying display light of an image formed on the light valve by the irradiated light. The present invention relates to a projection apparatus in which an image forming optical system for projecting an image to an optical system is composed entirely of reflective optical elements.

[0002]

2. Description of the Related Art A light source device, an illumination optical system for irradiating light from a light source to a light valve for forming an image, and an image forming optical system for projecting display light of an image formed on the light valve on the screen by the irradiated light. Most of the projection devices composed of a system include a refraction optical element such as a lens in the imaging optical system. The applicant of the present invention discloses a projection apparatus for projecting all the optical elements constituting the imaging optical system by using reflection optical elements as disclosed in Japanese Patent Application Laid-Open No. 8-53268.
1 and JP-A-8-295592.

The projection apparatus using a reflection optical element for the image forming optical system is an eccentric optical system, and the arrangement (interval) error and the angle error of each reflection optical element are the biggest causes of image deterioration.

Further, when a tilt adjustment is performed to correct an angle error which is one of the image deterioration factors, the arrangement (interval) is reduced.
Since an error occurs, it is necessary to adjust the arrangement (interval) after the tilt adjustment, which complicates the adjustment mechanism.

When the image forming optical system is composed entirely of reflective optical elements, it is very difficult to predict where the reflected light appears as stray light. In the case of a reflective light valve, it is difficult to predict the reflected light. An image is formed by utilizing the reflection. Although this diffused light appears as stray light, it is very difficult to block light because it is generated from the image display area itself. These stray lights pass through the aperture and reach the screen and the outside directly, which is one of the factors causing image deterioration.

[0006]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problem which occurs when the projection image forming optical system is constituted entirely by reflective optical elements.

The problem is the arrangement (interval) of the reflective optical element.
Improve the arrangement structure to eliminate errors and arrange (interval)
An object of the present invention is to provide a projection device that does not cause image deterioration by enabling a simple mechanism to correct an angle error without causing an error, and devising the arrangement and shape of a light-shielding plate to prevent the generation of stray light. .

[0008]

In order to solve the above-mentioned problems, a projection apparatus according to the present invention is a projection apparatus having an integral structure in which all reflecting optical elements constituting an image forming optical system are arranged in one housing. is there.

With the integral structure, the placement (interval) error of each reflective optical element can be managed by a single housing with respect to the mounting reference of each reflective optical element. Deterioration factor analysis is facilitated, and arrangement (interval) errors can be easily eliminated.

[0010] Further, since it has an integral structure, by using the back surface of one reflective optical element or the mounting reference surface of this reflective optical element as an angle reference, the angular error of the other reflective optical element can be easily made. Can be grasped and angle correction becomes easy,
Angle errors can be eliminated.

In addition, since it has an integral structure, a hole is provided on the housing side or the reflecting optical element mounting member so that the angle of the back surface of the reflecting optical element or the mounting reference plane can be observed, so that the angle at the time of assembly can be improved. Not only can correction be made, but also angle correction with a light valve arranged in a separate housing is facilitated, and image deterioration due to angle errors can be prevented.

At this time, if the back surface of the reference reflecting optical element is mirror-finished, the reference angle can be easily confirmed, and the angle correction of other reflecting optical elements can be further easily performed.

With respect to a reflective optical element requiring particularly strict angular accuracy with respect to the mounting reference surface, an error of the reflective optical element can be absorbed by providing a tilt adjustment mechanism on the mounting surface.

At this time, the tilt adjustment mechanism can be adjusted without generating an arrangement (interval) error by using an adjustment mechanism that rotates around the reference vertex of the reflective optical element.

By arranging a light shielding plate having a shape surrounding the effective light beam near the stop, harmful stray light can be efficiently cut.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a projection apparatus according to the present invention will be described below with reference to FIGS. In this embodiment, three mirrors are used for the reflection optical element. First, a configuration which is an example of an embodiment of the present invention will be briefly described with reference to FIGS.

FIG. 1 shows a central section in which each reflecting optical element is integrated into a single housing to form an integral structure. With reference to FIG. 1, the configuration of the reflecting optical element of the projection apparatus of the present invention will be briefly described. .

Reference numeral (1) denotes a housing in which each reflecting optical element is integrally formed. Symbol (2) is a light valve (0)
(Hereinafter, referred to as a first mirror). Reference numeral (3-1) denotes a reflection optical element (hereinafter, referred to as a second mirror) that receives the reflected light from the first mirror (2), and reference numeral (3) denotes an attachment of the second mirror (3-1). 2 shows the second mirror unit shown in FIG. Reference numeral (4-1) denotes a reflection optical element (hereinafter, referred to as a third mirror) that receives the reflected light from the second mirror, and reference numeral (4).
Indicates a third mirror unit to which the third mirror (4-1) is attached. The third mirror (4-1)
A hole (4-2 ') for mounting surface observation is formed in the third mirror plate (4-2) which is a member for fixing. The first mirror (2) has a flat concave shape.
This is a glass polished mirror with a mirror-finished rear surface. The second mirror (3-1) is a rotationally symmetric aspheric glass mold mirror, and has a reference vertex (3--1).
A sphere R for attachment reference is formed on the back surface which is the attachment reference surface coaxially with 1a). Third mirror (4-1)
Is a rotationally symmetric aspherical plastic mold mirror, on the back surface of which is formed a planar projection for attachment reference. Reference numeral (5) denotes a stop, reference numeral (6) denotes a light shielding plate 1, and reference numeral (7) denotes a light shielding plate 2. The display light from the light valve (0) is reflected by the first mirror (2), passes through the stop (5), is reflected by the second mirror (3-1), and is further reflected by the third mirror (4-1). And an image is projected on a screen (not shown).

With reference to FIG. 2, a description will be given of a case in which each of the reflective optical elements has an integral structure. 2, (a) is a front view, (b) is a top view, (c) is a right side view, (c ′) is a central cross-sectional view, (d) is a left side view, (e) is a rear view, f)
Shows a back view. Note that X, Y, and Z described in the following description correspond to the X, Y, and Z axes shown in FIG.

The hatched portion (1-A) shown in FIG.
Is a reference for the height (Y) of the reflection optical system, and serves as a reference plane for attachment to another housing constituting an image forming unit (not shown). Also, (1-B) and (1-B) shown in (f)
C) is a reference for attaching Z and X to another housing which also forms an image forming unit (not shown). (1-1a),
(1-a ′) and (1-a ″) are mounting reference surfaces of the first mirror (2), and slit-shaped holes (1-1b) are formed in the reference surface (1-a). ing. (1-2a),
(1-2b) and (1-2b ') are reference mounting surfaces of the second mirror unit (3), which regulate Z and Y.
c) is a slot for positioning the second mirror unit (3) in the X direction. (1-3a) and (1-3a ') correspond to the third
It is the mounting reference surface of the mirror unit (4) and regulates in the Y direction, and (1-3b), (1-3b '), (1-3b)
c) and (1-3c ′) are X and Z of the third mirror (4-1).
It is a hole for positioning in the direction. (1-4a) (1-4
b) are a Z reference plane and a Y reference plane of the diaphragm (5), and the posts (1-4c) regulate the X reference.

Referring to FIG. 3, the configuration of the angle adjusting mechanism of the second mirror (3-1) will be described. (A) is a central sectional view,
(B) is an arrow A view.

The second mirror (3-1) is fixed to a second mirror-mounting shaft (3-2). Second mirror (3-
On the back surface of 1), a sphere R shape for attachment reference is formed. A sphere R having the same shape as the sphere R is also formed on the second mirror mounting shaft (3-2).
The mirror (3-1) is fixed. On the surface of the second mirror mounting shaft (3-2) opposite to the second mirror mounting surface,
A sphere R shape centered on the second mirror reference vertex (3-1a) is formed. Since the second mirror (3-1) is formed by a glass mold, the second mirror (3-1) is formed so as to have a vertex substantially at the center of a use area in order to increase the accuracy of the surface shape of the reflection surface while avoiding an uneven thickness structure. The sphere R shape on the back surface is formed so that the axis coincides with the vertex. Second mirror plate (3
-3) includes the second mirror mounting shaft (3-2).
And a sphere R centered on the second mirror reference vertex (3-1a) is similarly formed on the opposite surface.
A shape is formed. Second mirror adjustment nut (3-
4), a sphere R having the same shape as the sphere R formed on the second mirror plate (3-3) is formed. The second mirror mounting shaft (3-2) and the second mirror plate (3--2)
3) is rubbed and attached to the same sphere R shape formed mutually. Also, the second mirror adjustment nut (3-4) and the second mirror plate (3-3) are rubbed and attached to the same spherical R shape formed mutually. Further, the second mirror adjustment nut (3-4) is inserted into the shaft of the second mirror mounting shaft (3-2). The second mirror mounting shaft (3-2) has a threaded portion formed therein, and the second mirror adjusting nut (3-4) and the wave washer (3--3).
5) is fixed with screws (3-6). The second mirror adjustment nut (3-4) and the second mirror mounting shaft (3-2) are appropriately biased by the corrugated washer (3-6) to form the second mirror plate (3). It can move along the sphere R shape formed in -3). The second mirror fixing base (3-7) is fixed to the second mirror plate (3-3). The second mirror fixed base (3-7) and the second mirror adjustment piece (3-
8) is rubbed by a tapered surface, and the second mirror adjustment piece (3-8) is given a spring bias by a compression spring (3-9) and is fixed to the second mirror by a tilt adjustment screw (3-10). It is fixed to the base (3-9). The second mirror adjustment nut (3-4) is provided with a second mirror pressure spring (3--4).
It is pushed by a second mirror pressure pin (3-12) which is biased by a spring by 11), and is regulated and fixed by a second mirror adjustment piece (3-8). The second
Two mirror adjustment pieces (3-8) are arranged in a 90-degree positional relationship as shown by arrow A in FIG. 2B. Further, the second mirror unit (3) includes a bottom surface (3-13a) and a front surface (3-13a) of the base plate (3-13).
b) and the half piercing (3-13c) are used as mounting standards.

The configuration of the third mirror unit (4) will be described with reference to FIG. (A) is a rear view, (b)
Is a right side view, in which the third mirror (4-1) is omitted. Further, since the mechanism for fixing the third mirror plate (4-2) is the same mechanism on the left and right sides, the right half in the rear view is omitted.

The third mirror (4-1) is mounted with reference to a mounting reference surface (4-2a) of the third mirror plate (4-2) and a plane (4-2a ') provided at the bottom. , Is fixed by a clip spring (not shown) via a slit (4-3a) formed on a side surface of the third mirror plate (4-2). The third mirror plate (4-2) has a mounting reference surface (4-2a) and a hole (4-2 ') for observation. Third mirror (4-
The third mirror plate (4-2) integrated with 1) is
A rotation operation can be performed around the link pin (4-4). One poly-slider (4-6) is provided between the third mirror plate (4-2) and the third mirror BRK (4-5), and the third mirror BRK (4-5) and the mirror plate fixing plate (4-7) also between the poly slider (4-
6), and a brake spring (4-8) is sandwiched therebetween and fixed with a mirror link set screw (4-9). Appropriate friction is generated by the poly slider (4-6) and the brake spring (4-8), and the rotation operation is made smooth. In the third mirror BRK (4-5), a V-groove (4-5a) for clicking is formed symmetrically at a position of 45 degrees. The mirror plate fixing plate (4-7) has a click spring (4-
10) is attached, and clicks (not shown) are regulated by V-grooves (4-5a) formed in the third mirror BRK (4-5) to perform positioning during projection and storage. . The third mirror unit is a third mirror B
The bottom surface (4-5b) of the RK (4-5) and the half piercings (4-5c) and (4-5d) are used as mounting standards.
A screw (4-2 '') for adjusting the angle is provided on a side surface of the third mirror plate (4-2), and a long hole (4-7a) is provided on the mirror plate fixing plate (4-7). At the click position, the third mirror plate (4-2)
Is rotated and adjusted to the reference angle, and screwed and fixed.

The operation (operation) of the projection device of the present invention configured as described above will be described in detail below.
First, mounting (arrangement) of the first mirror (2), the second mirror unit (3), and the third mirror unit (4) and the housing (1) will be described with reference to FIGS. 2, 3, and 4. FIG.

The first mirror (2) has a plano-concave shape, and the flat surface on the back surface has a mirror-finished surface and an oval outer shape in which knitting core tolerance is suppressed. The concave surface has a simple spherical shape and can be machined with sufficient accuracy as a single component including centering. The first mirror mounting surface (1) of the housing (1) shown in FIG.
−a ′) and (1-a ″) are formed according to the external dimensions. In addition, the mounting reference plane (1
-A) is formed perpendicular to (1-A), which is a reference plane for attachment to another housing forming the image forming unit.

The first mirror (2) is connected to the reference surface (1-
a) is restricted in the angle and the Z direction according to a), and is mounted under the restriction in the Y and X directions by the reference planes (1-a ') and (1-a'').

The aperture (5) is restricted in the X direction by the post (1-4c) of the housing (1) shown in FIG.
-4b) and (1-4c), it is attached under the regulation in the Y and Z directions.

The second mirror unit (3) to which the second mirror (3-1) is fixed is a mirror base (3) shown in FIG.
The regulation in the X direction is performed by the half piercing (3-13c) for reference positioning formed in -13) and the reference long hole (1-2c) formed in the housing (1) shown in FIG. The reference planes (3-13a) and (3-13b) formed on the mirror base (3-13) correspond to the reference planes (1-2a) and (1-13) of the housing (1) shown in FIG. 2b) and (1-
2b '), the Y and Z directions are regulated by being applied to the mounting.

The third mirror unit (4) to which the third mirror (4-1) is fixed is the third mirror BRK shown in FIG.
The reference half piercing (4-5) formed in (4-5)
c) and (4-5d) are the reference holes (1-3b), (1-3c), (1-3b '), and (1-3) of the housing (1) shown in FIG.
-3c ′), the reference plane (4-5b) formed on the third mirror BRK (4-5) shown in FIG. 4 is shown in FIG. ) Is attached to the reference planes (1-3a) and (1-3a ') by restricting the Y direction.

As described above, each of the reflective elements is mounted by being positioned in the X, Y, and Z positions by the reference surface and the reference hole formed in one housing (1), thereby forming an integral structure. ing. Thereby, it is possible to easily manage the arrangement error caused by the individual mounting with reference to the housing (1).

In this embodiment, the second mirror (3-
Although the unit 1) and the third mirror (4-1) are unitized, it is easy to measure the arrangement error of the unit alone, and all the reflective optical elements are integrated into one housing (1) to form an integrated structure. Since the number of complex elements is extremely small, it is possible to easily analyze the cause of image deterioration due to an arrangement error, and easily prevent image deterioration due to an arrangement (interval) error.

Further, the arrangement of the light valve (0) shown in FIG. 1 is shown corresponding to the mounting reference holes (1-B) and (1-C) formed in the housing (1). If it is performed from the reference post on the separate housing that forms the image forming unit, it is easy to confirm the arrangement error of the light valve (0), and the arrangement error (separation) of the light valve (0) arranged in the separate housing is caused. Image degradation can be easily prevented.

Next, the angle correction of each reflective optical element will be described with reference to FIGS. In this description, it is assumed that the above-described second mirror unit (3) and third mirror unit (4) have already been attached to the housing (1). In this embodiment, the first mirror attachment reference plane (1-a) is used as the angle reference of each reflection optical element.

As is clear from FIGS. 1 and 2A and 2E, the slit (1-a) formed on the first mirror mounting reference surface (1-a) of the housing (1). It can be seen through b) that the second mirror mounting reference surface of the second mirror mounting shaft (3-2) can be easily observed. Further, a third mirror (4-1) for mounting the third mirror (4-1) is provided.
Mounting reference surface (4-2a) for mirror plate (4-2)
The hole (4-) provided in the third mirror plate (4-2) is also
It can be easily observed through 2 ′). Moreover, since this slit (4-2 ') is formed relatively close to the slit (1-b) of the housing (1), the first
Observation can be made simultaneously with the mirror attachment reference plane (1-a).

First, the first mirror mounting reference plane (1-a)
Set a parallel flat plate as a reference and set the reference for the collimator. Next, the second mirror mounting shaft (3-
Similarly, a parallel flat plate or the like is set on the second mirror mounting reference plane in 2), and adjustment (X and Y rotation) is performed with the tilt adjustment screw (3-10) so that the mounting reference plane falls within a specified range. Since the mounting reference surface of the second mirror (2-1) in this embodiment is already formed at a certain angle, a wedge-shaped reference jig suitable for this angle is mounted on the second mirror mounting shaft (3--3). The camera is set on the second mirror mounting reference plane in 2), and the tilt is adjusted. Similarly, the third mirror mounting reference surface (4-2a) of the third mirror plate (4-2).
Set a parallel flat plate, etc., loosen the angle adjustment screw so that the mounting reference plane falls within the specified range, and rotate (X rotate) the third mirror plate (4-2) to set the position within the allowable range. Then, screws are fixed together with the mirror plate fixing plate (4-7). The third mirror (4-
Since the permissible ranges of the arrangement error and the angle error in 1) are relatively large and the third mirror (4-1) is relatively large, the Y-axis rotation error is provided in the third mirror BRK (4-5). Half piercings (4-5c), (4-5d) and fixing reference holes (1-3b), (1-3c), 1-
Since the position accuracy (processing accuracy) of (3b ′) and (1-3c ′) can be sufficiently covered, the Y rotation is not adjusted. Finally, the first mirror (2) is attached and checked.

As described above, each reflective optical element is
Since it is arranged in one housing and has an integral structure, the angle correction of each reflective optical element becomes easy, and image deterioration due to an angle error can be easily prevented. As described above, the first mirror (2) of this embodiment is a glass spherical polished mirror whose rear surface is mirror-finished. Here, the effectiveness of making the rear surface of the reflective optical element a flat mirror finish will be described.

The first mirror mounting reference plane (1-a) has the first
Attach the mirror (2) and set the collimator reference. next,
Remove the first mirror and attach the second mirror mounting shaft (3-
2) A parallel flat plate or the like is set on the second mirror mounting reference plane, and adjustment (X-axis and Y-axis rotation) is performed with the tilt adjustment screw (3-10) so that the mounting reference plane falls within a specified range. As described above, in this embodiment, the wedge-shaped jig is
The tilt adjustment is performed by setting the mirror mounting shaft (3-2) on the second mirror mounting reference surface. After the tilt adjustment of the second mirror (2) is completed, the first mirror (2) is mounted. Similarly, a parallel flat plate or the like is set on the third mirror attachment reference surface (4-2a) of the third mirror plate (4-2), and the angle adjusting screw is loosened so that the attachment reference surface falls within a specified range. Then, the third mirror plate (4-2) is rotated (X-axis rotation), and screwed and fixed together with the mirror plate fixing plate (4-7) at a position within an allowable range. As described above, in the present embodiment, the Y-axis rotation is not adjusted.

As described above, since the back surface of the first mirror (2) has a flat mirror finish, individual component errors of the first mirror (2) and the first mirror mounting reference surface (1-a) are determined. It is possible to perform the angle correction of each reflective optical element by absorbing the variation, and the accuracy of the angle correction is further improved.

Here, the tilt adjustment mechanism of the second mirror (3-1) requiring particularly strict angular accuracy will be described in detail with reference to FIG. Since the configuration of the adjustment mechanism has been described above, the operation (operation) is described here.
Will be described in detail.

In the center sectional view of FIG. 3A, when the tilt adjustment screw (3-10) is rotated clockwise, the second mirror adjustment piece (3-8) is attached to the second mirror fixing base (3-7). It moves rightward along the formed tapered surface and also moves downward. Therefore, the second mirror adjustment nut (3-4) is urged downward,
The second mirror adjustment nut (3-4) is provided with a wave washer (3-4).
-5), the second mirror plate (3-
3) with the second mirror mounting shaft (3-2) with the sphere R centered on the second mirror reference vertex (3-1a).
Since the second mirror adjustment piece (3-8) is rubbed with the shape, the downward biasing force of the second mirror adjustment piece (3-8) is applied to the second mirror adjustment nut (3-4) by the second mirror mounting shaft (3--8).
Together with 2), it acts as a counterclockwise (left) rotational movement (X-axis rotation) around the second mirror reference vertex (3-1a). Since the second mirror adjusting nut (3-4) is always pushed by the second mirror pressure pin (3-12) which is urged by the second mirror pressure spring (3-11), the second mirror is adjusted. It is fixed at the adjustment position of the adjustment piece (3-8).

When the tilt adjustment screw (3-10) is rotated counterclockwise, the second mirror adjustment piece (3-8) is moved leftward by the urging force of the compression spring (3-9), The second mirror adjusting nut (3-4) which receives an upward biasing force by the second mirror pressure pin (3-12) which is biased by the second mirror pressure spring (3-11) and moves upward. And is regulated by being rubbed against the tapered surface formed on the second mirror fixing base (3-7). As described above, the second mirror adjustment nut (3-4) receives the spring bias of the wave washer (3-5), and the second mirror adjustment nut (3-4) sandwiches the second mirror plate (3-3).
Since it is rubbed together with the mirror mounting shaft (3-2) in a spherical R shape centered on the reference vertex (3-1a) of the second mirror (3-1), the second mirror adjusting nut (3 -4) The upward movement is performed with the second mirror mounting shaft (3-2) and the second mirror reference vertex (3--3).
1a) acts as a clockwise (right) rotational movement (X-axis rotation) around the second mirror adjustment piece (3-
It is fixed at the adjustment position of 8).

Accordingly, the angle correction of the mounting surface of the second mirror (3-1) is performed centering on the second mirror reference vertex (3-1a), and even if the angle correction by the tilt adjustment described above is performed. The origin (31b) of the second mirror aspheric surface of the second mirror (3-1) returns to the normal position. Therefore, even if the angle correction is adjusted, it is possible to prevent the occurrence of an error in the arrangement (interval) of the second mirror.

The angle correction by the Y-axis rotation can be performed by another second mirror adjustment piece (3-8) arranged at 90 degrees as shown by arrow A in FIG. The operation is the same as the operation described above, and the description is omitted.

The second mirror adjustment piece (3-8) is 90
Since they are arranged at intervals of degrees, it is possible to independently perform the angle correction of the X-axis rotation and the Y-axis rotation, and the work efficiency of the angle correction is extremely high.

As described above, each reflecting optical element is
It is possible to easily correct the angle of another reflective optical element by forming an integral structure in one housing and forming a hole for angle observation on the reflective optical element mounting reference surface. In addition, by making the back surface of the reflective optical element used as an angle reference a flat mirror surface finish, it is possible to correct the angle by absorbing the dispersion of individual components, thereby improving the accuracy of the angle correction. Even for reflective optical elements that require strict angular accuracy and placement (interval) accuracy, the tilt adjustment mechanism with the reference vertex as the center of rotation enables angle correction without causing an arrangement (interval) error. is there. Therefore, it is possible to easily prevent image deterioration due to an angle error.

Further, as shown in FIG.
Since the reference surface (1-A) and the positioning holes (1-B) and (1-C) are formed with respect to the casing that forms the image forming unit (not shown), the casing after the above-described angle correction is completed. The body (1) is assembled in a separate housing constituting the image forming unit, and a collimator is set on the basis of the back surface of the first mirror (2), so that the angle of the light valve (0) shown in FIG. 1 can be corrected.

As a result, it becomes easy to keep the angles of the reflecting optical elements including the light valve (0) within a predetermined allowable range, and it is possible to further prevent image deterioration due to an angle error.

In addition, since the distance between the reference holes (1-B) and (1-C) provided in the housing (1) is made as long as possible, the reference holes (1-B) and (1-C) are incorporated into the housing (1). It is possible to minimize the angular deviation due to mechanical play that sometimes occurs.

Finally, the effectiveness of disposing a light shielding plate in the vicinity of the stop (5) so as to enclose an effective light beam will be described.

When a reflection type liquid crystal is used for a light valve for forming an image, the image is formed by reflection and diffusion. This diffused light is unnecessary light and becomes stray light. But,
This stray light is emitted from the image display area itself, and there is a very high risk that cutting this stray light will cut even the effective light.

This state will be described with reference to FIG. FIG.
FIGS. 2A and 2B are diagrams schematically illustrating the configuration of an image forming unit, a first mirror (2), and a diaphragm (5) according to an embodiment of the present invention. FIG. It is a top view. still,
In this embodiment, three reflective liquid crystals are used for the light valve, (8-B) is for blue, (8-G) is for green, and (8-G) is for green.
-R) is a reflective liquid crystal used for red. Also,
(8-DR) is a dichroic mirror for red color separation and synthesis, and (8-DG) is a dichroic mirror for green color separation and synthesis. The dashed lines represent the luminous flux from each reflective liquid crystal toward the first mirror (2), and the thin lines represent the luminous flux from the first mirror (2) toward the stop (5) and the second mirror (not shown).

As is apparent from FIG. 5, the overlap region of the combined light beam going to the first mirror (2) and the light beam going from the first mirror (2) to the stop (5) is considerably wide. You can see that. In particular, the reflective liquid crystal for red (8-R) has a position substantially opposite to the stop (5), and the light beam directed to the dichroic mirror (8-DR) is reflected by the reflective liquid crystal for red (8-R). It can be seen that it enters the overlap region in the vicinity. As described above, in the case of the reflection type liquid crystal, since the image formation is performed by reflection and diffusion, unnecessary light and stray light itself is generated from the image display region of the reflection type liquid crystal itself. Therefore, the image display area itself cannot be shielded from light, and a light shielding plate or the like cannot be arranged in the overlap area. Further, what makes the light shielding difficult is that the stray light passes through the overlap of the effective light beams, reaches the stop (5), and exits from the stop (5).

Referring to FIG. 6 showing one example of the shape and arrangement of the light-shielding plate, the effectiveness of the light-shielding plate having a shape surrounding the effective light beam is described in the vicinity of the stop. (A) is a front view, (b) is a side view, (c) is a rear view, and the housing (I) is omitted in (a) and (c). Reference numerals (9-1a) to (9-1f) denote effective luminous fluxes from the first mirror (2) (not shown) to the stop (5), and reference numerals (9-2a) to (9-2d).
Denotes an effective light beam passing through the stop (5) and traveling toward the second mirror (not shown).

As is clear from the side view (b) of FIG.
The light shielding plate 1 (6) is a first light valve (not shown).
The light flux toward the mirror (2) (the broken line in the figure represents the upper ray of the light flux) and the light flux extending from the first mirror (2) to the second mirror (3-1) are extended to the overlap area limit. As can be seen from the rear view (c), it is understood that the overlapping region is avoided by forming a shape enclosing the effective light beam. Further, by disposing it near the stop, it is possible to efficiently block stray light passing through the effective light flux as described above. In particular, the light blocking plate (6) effectively blocks the emission of diffused light of the reflection liquid crystal for red (not shown). Further, although it is very difficult to predict where stray light is generated, the light shielding plate 2 (7) is arranged near the exit side of the stop (5), and only the effective light beam emitted from the stop (5) is emitted. By making the shape pass through, stray light can be effectively shielded from being emitted to the outside due to a synergistic effect with the light shielding plate 1 (6).

As is apparent from the above embodiment, when all the reflecting optical elements are used in the image forming optical system, the arrangement error and the angle error of each reflecting optical element which cause image deterioration can be easily corrected, and the stray light can be easily corrected. It has been demonstrated that the generation can be effectively prevented. Note that this embodiment is merely one embodiment. Depending on the total number of reflective optical elements and the layout of each reflective optical element, it is not necessary to limit the reference reflective optical element to the first reflective optical element that receives light from the light valve. Further, the back surface reference may be provided on the reflection surface side, or an error between the reference surface and the opposite surface may be measured in advance instead of providing a hole, and the error may be corrected and adjusted. Further, it is also possible to provide a secondary reference surface and similarly adjust the angle by correcting the error. Instead of performing the angle correction of another reflective optical element on the reference plane of one reflective optical element, the angle correction of each reflective optical element may be performed sequentially by performing the angle correction. In this embodiment, the light-shielding plate and the stop are formed of different members. However, the light-shielding plate and the stop may be formed integrally, or the light-shielding plate may be formed in a cylindrical shape. Further, in this embodiment, the description is made for the front projection type device, but the same applies to the rear projection type device.

[0056]

As described above, in a projection apparatus in which all imaging optical systems use reflection optical elements, all the reflection optical elements are arranged in one housing to form an integral structure, thereby reducing the arrangement error and Complex factors that cause an angle error are extremely reduced, and the arrangement (interval) of each reflection optical element and the angle error can be easily grasped, and the correction thereof can be easily performed. Further, by forming a hole for observing the angle of the reference plane with respect to the mounting reference plane of the reflective optical element, the angle correction is further facilitated, and one reflective optical element is used as an angle reference for other reflective optical elements. Angle correction becomes possible. As a result, it is possible to efficiently and easily prevent the image deterioration caused by the arrangement error and the angle error.

One reflection optical element is used as an angle reference by forming a mounting reference surface, a mounting reference boss, a hole, and the like on each of a housing having an integral structure of a reflection optical element and a housing constituting an image forming portion. As a result, the correction of the angle of the light valve is facilitated, the arrangement error of the light valve can be easily grasped, and the arrangement error of the light valve can be easily prevented. As a result, an arrangement error and an angle error of the entire imaging optical system including the light valve can be easily corrected, and the image deterioration can be further prevented.

For a reflective optical element requiring particularly strict angular accuracy and arrangement (interval) accuracy, a mechanism for rotating the reflective optical element around a reference vertex is provided.
The angle can be corrected without causing an arrangement error, and image deterioration can be prevented. In addition to the rotation mechanism, X,
There is no need for a Y and Z adjustment mechanism, which simplifies and stabilizes the mechanism and also prevents an increase in cost. Further, since it is not necessary to request the angular accuracy of the mounting reference surface of the reflection optical element more than necessary, the cost can be prevented from increasing.

By providing a light shielding plate in the vicinity of the stop so as to enclose only the effective light beam as much as possible, it is possible to effectively prevent the generation of stray light.

[0060]

[Brief description of the drawings]

FIG. 1 is a central sectional view showing an embodiment of the present invention.

FIG. 2 is a 6-side view and a center cross-sectional view of a housing having an integral structure, showing an embodiment of the present invention.

FIG. 3 is a second mirror unit diagram showing the embodiment of the present invention.

FIG. 4 is a diagram showing a third mirror unit according to the embodiment of the present invention;

FIG. 5 is a schematic diagram of a light beam showing an embodiment of the present invention.

FIG. 6 is a set view of a light shielding plate showing an embodiment of the present invention.

[Explanation of symbols]

Reference Signs List 0 light valve 1 housing having a reflective optical element as an integral structure 1-A height (Y) reference plane of imaging optical system 1-B reference Z mounting position with housing forming image forming unit 1-C X mounting position reference with respect to the housing constituting the image forming unit 1-1a First mirror mounting reference plane 1-1a 'Same as above 1-1a''Same as above 1-1b First mirror mounting reference plane observation slit 1-2a Second mirror unit mounting reference surface 1-2b Same as above 1-2b 'Same as above 1-2c Second mirror unit positioning hole 1-3a Third mirror unit mounting reference surface 1-3a' Same as above 1-3b Third mirror unit positioning hole 1 1-3b Same as above 1-3c Same as above 1-3c 'Same as above 1-4a Z reference plane of stop 1-4b Y reference plane of stop 1-4c X reference post of stop 2 First mirror 3 Second mirror unit 3-1 First stop 2 mirror 3-1a 2 mirror reference vertex 3-1b 2nd mirror origin 3-2 2nd mirror mounting shaft 3-3 2nd mirror plate 3-4 2nd mirror adjustment nut 3-5 Wave washer 3-6 screw 3-7 2nd mirror fixing Base 3-8 Second mirror adjustment piece 3-9 Compression spring 3-10 Tilt adjustment screw 3-11 Second mirror pressure spring 3-12 Second mirror pressure pin 3-13 Base plate 3-13a Base plate bottom surface 3-13b Base plate front surface 3-13c Half earring 4 Third mirror unit 4-1 Third mirror 4-2 Third mirror plate 4-2 'Third mirror mounting reference surface observation slit 4-2''Angle adjusting screw 4-2a Third Mounting reference surface 4-2a 'Plane at bottom of third mirror plate 4-3a Slit for third mirror fixing clip spring 4-4 Phosphorus Pin 4-5 Third mirror BRK 4-5a V groove for click 4-5b Third mirror BRK bottom surface 4-5c Half piercing 4-5d Same as above 4-6 Poly slider 4-7 Mirror plate fixing plate 4-7a Slot 4 -8 Brake spring 4-9 Mirror link screw 4-10 Click spring 5 Aperture 6 Light shield 1 7 Light shield 2 8-R Reflective liquid crystal for red 8-G Reflective liquid crystal for green 8-B Reflective liquid crystal for blue 8-DR Dichroic mirror for red color separation and synthesis 8-DG Dichroic mirror for green color separation and synthesis 9-1a Effective light flux from the first mirror toward the stop 9-1b Same as above 9-1c Same as above 9-1d Same as above 9-1e Same as above 9- 1f Same as above 9-2a Effective luminous flux from stop to second mirror 9-2b Same as above 9-2c Same as above 9-2d Same as above

Claims (6)

[Claims] An illumination optical system for irradiating a light source device and light from a light source to a light valve for forming an image, and an imaging optics for projecting display light of an image formed on the light valve on the screen by the emitted light. In a projection device configured with a system, all the optical elements that constitute the imaging optical system are configured using reflective optical elements, and all of the reflective optical elements are arranged in one housing to form an integral structure. Characteristic projection device. 2. A projection device, wherein a hole for observing an angle of a back surface or an attachment reference surface of the reflective optical element having the integral structure is provided in a housing or an attachment member. 3. A projection apparatus, wherein at least one of the reflective optical elements has a flat mirror-finished back surface. 4. An illumination optical system for irradiating a light source device and light from a light source to a light valve for forming an image, and an imaging optics for projecting display light of an image formed on the light valve on the screen by the irradiated light. In the projection device configured with a system, all the optical elements constituting the imaging optical system are configured using reflective optical elements, and a tilt adjustment mechanism is provided in at least one of the reflective optical elements. A projection device characterized by the above-mentioned. 5. The projection device according to claim 1, wherein the tilt adjustment mechanism is a mechanism that rotates about a reference vertex of the reflection optical element. 6. An illumination optical system for irradiating a light source device and light from a light source to a light valve for forming an image, and an imaging optics for projecting display light of an image formed on the light valve on the screen by the emitted light. In a projection system composed of a system, all the optical elements constituting the imaging optical system are configured using reflective optical elements, and to shield stray light that directly passes through the stop, so as to wrap the effective light flux near the stop. A projection device comprising a light shielding plate having a simple shape.