JP2016224120A - Reflection type optical element and image projection device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a downsized reflection type optical element as maintaining high anchoring accuracy.SOLUTION: A reflection type optical element 40 comprises: a reflection unit 41 that includes a symmetric reflection plane 41a with respect to a reference axis Y for reflecting an image projected from an image projection device main body side toward a projection plane with the image as a projection image Q; a first positioning part 43 that is provided protrudingly in an X-direction vertical to the reference axis Y in an outer peripheral part 42 of the reflection unit 41, and is for provisionally positioning an attachment position of the reflection type optical element 40 to the image projection device main body side; and a second positioning part 44 that is provided protrudingly on a side opposite the first positioning part 43 across the reference axis Y, and positions the attachment position of the reflection type optical element 40 to the image projection device main body side.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a reflective optical element and an image projection apparatus.

  In an image projection apparatus using a lens unit typified by a projector, an image projection apparatus that projects an image on a projection surface using a reflective optical element in a projection optical system is known (for example, see Patent Document 1).

  A reflection type optical element is required to have a small size of the reflection type optical element as well as high fixing accuracy to the image projection apparatus main body.

  The present invention has been made in view of the above-described problems, and an object thereof is to provide a compact reflective optical element while maintaining high fixing accuracy to the image projection apparatus main body.

  In order to solve the above-described problems, a reflective optical element according to the present invention is a reflection symmetric with respect to a reference axis for reflecting an image projected from the image projection apparatus main body side toward a projection plane as a projection image. A reflection portion having a surface, and an outer peripheral portion of the reflection portion that protrudes in a direction perpendicular to the reference axis, and temporarily determines the attachment position of the reflection type optical element with respect to the image projection apparatus main body side A first positioning portion for projecting in the perpendicular direction on the opposite side of the first positioning portion across the reference axis, and the attachment position of the reflective optical element with respect to the image projection apparatus main body side And a second positioning portion for positioning.

  ADVANTAGE OF THE INVENTION According to this invention, a compact reflective optical element can be provided, maintaining the high fixation precision to an image projector main body.

It is a figure which shows an example of a structure of the image projector in embodiment of this invention. It is a perspective view which shows an example of a structure of the reflection type optical element in embodiment of this invention. It is a schematic diagram which shows an example of a structure of the reflective optical element shown in FIG. FIG. 4 is a trihedral view showing an example of the configuration of the reflective optical element shown in FIG. 3 in a fixed state. It is sectional drawing which shows an example of the process at the time of attachment of the reflective optical element shown in FIG. It is a schematic diagram which shows an example of a structure of the comparative example with respect to embodiment of this invention.

As an embodiment of the present invention, an example of the configuration of an image projection apparatus is shown in FIG.
The image projection apparatus 100 includes a light source 101 that emits a light beam L, a spatial light modulation element 102 that planarly displays an image to be projected as image information, and modulates the light beam L, and a light source 101 and a spatial light modulation element 102. And a housing 20 as a housing.
The image projection apparatus 100 also includes a lens unit 200 that is a projection optical system for projecting an image on the projection plane 104 and a control unit 109 that controls the spatial light modulation element 102 to display an image to be projected on the projection plane 104. And have.
The image projection apparatus 100 also includes a reflection mirror 40 that is a reflective optical element for reflecting the projection image Q projected from the lens unit 200 and projecting it onto the projection surface 104.

The light source 101 emits white light substantially in parallel using a halogen lamp that is a light source that emits light. Here, a metal halide lamp, a high-pressure mercury lamp, or an LED may be used as the light source.
Although the light source 101 is a white light source, a plurality of monochromatic light sources such as laser light sources corresponding to basic colors such as R, G, and B may be used.

  The spatial light modulation element 102 is a liquid crystal panel that is an image display unit that provides image information by transmitting an incident light beam L, applying spatial modulation, and emitting the light. The spatial light modulator 102 may be a reflective spatial light modulator such as a DMD (digital micromirror device).

  The lens unit 200 has at least one lens and is an imaging optical system that forms an image of the light beam L that has passed through the spatial light modulation element 102 and is a projection optical system that projects an image onto the projection plane 104. .

The reflection mirror 40 is disposed downstream of the lens unit 200 in the optical axis direction of the light beam L and upstream of the projection surface 104.
As shown in FIG. 2, the reflection mirror 40 is attached to a housing 20 as a housing portion that is a main body portion of the image projection device 100, and plastic or the like for reflecting the projection image Q formed by the lens unit 200. This is a resin-made reflective member.

As shown in FIG. 3, the incident direction of the light beam L that has passed through the lens unit 200 is the Z direction, the optical axis is the Z axis, the reference axis that is the symmetry axis of the reflection mirror 40 is the Y axis, and the Z axis and the Y axis The orthogonal axes are defined as the X axis, and the respective axial directions are defined as the Y direction and the X direction.
As shown in FIG. 3, the Y axis is set so as to pass through the central portion O that is the center point in the X direction and the Y direction of the projection image Q. Therefore, in the present embodiment, the Y axis is determined so as to coincide with the reference axis of the reflection mirror 40 and is also a vertical axis extending in the vertical direction of the projection image Q, that is, the V direction which is the vertical direction.
As is apparent from the above description, the vertical direction corresponding to the vertical direction of the projection image Q projected on the reflection mirror 40 is the Y direction, and similarly the longitudinal direction of the image projected on the reflection mirror 40, that is, the horizontal direction H. The direction matches the X direction.
Hereinafter, in particular, when it is desired to specify the direction, each of the X, Y, and Z directions is indicated by + or −.

As shown in FIG. 3 or FIG. 4, the reflection mirror 40 has a main body 41 as a reflection portion including a reflection surface 41 a that is a curved surface that is convexly curved in the + Z direction for reflecting the light beam L.
The reflection mirror 40 has four support portions 42 provided on the outer peripheral portion, which is the outer edge of the four corners of the main body portion 41, so as to protrude from the main body portion 41 along the ± X direction.
The support portions 42 are four ear portions provided on the outer peripheral portion of the main body portion 41 so as to protrude from the main body portion 41 on the opposite side to the Y axis. Since the support portions 42 are provided at the four corners of the main body portion 41, the support portions 42 are disposed at the −Z direction side end portions of the main body portion 41 in the present embodiment.
The reflection mirror 40 is any one of the support portions 42, and in this embodiment, of the two support portions 42 arranged on the + Y direction side in FIG. 3, the support portion 42 located on the upper left protruding in the −X direction. In addition, the first positioning portion 43 which is a hemispherical protrusion convex in the −Z direction is provided.
The first positioning part 43 may be formed on any support part 42.

The reflection mirror 40 is symmetrical with respect to the first positioning portion 43 and the Y-axis, that is, is formed on the support portion 42 that is disposed at the upper right in FIG. 3 and protrudes in the + X direction, and is convex in the −Z direction. The second positioning portion 44 is a protruding portion.
That is, the second positioning portion 44 is formed on the support portion 42 that protrudes in the + X direction from the main body portion 41 among the two support portions 42 arranged on the + Y direction side.

The reflection mirror 40 includes a plurality of, here, two screwing openings formed in the support portion 42 disposed on the −Y direction side with respect to each of the first positioning portion 43 and the second positioning portion 44. It has the fixed part 45 which is.
That is, the fixed portion 45 is formed on each of the two support portions 42 arranged on the −Y direction side.
In the present embodiment, the two fixing portions 45 are formed symmetrically with respect to the Y axis. However, if the two fixing portions 45 are fixed with respect to the housing 20, they are formed at positions shifted from each other with respect to the Y axis. May be.

The reflection mirror 40 is integrally formed of a resin material as a whole. Therefore, the first positioning portion 43 and the second positioning portion 44 are formed of resin integrally with the support portion 42.
The first positioning part 43 and the second positioning part 44 are in a temporarily determined state in which the position of the first positioning part 43 is in contact with the housing 20 and temporarily determined in an attachment operation described later. The part 44 is positioned.

The main body 41 is a member that is curved into an aspheric shape formed symmetrically with respect to the Y axis.
Aluminum is vapor-deposited on the surface of the main body 41 on which the light flux L is irradiated, that is, the surface on which the projection image Q is projected, in other words, the surface on the −Z direction side.
With this configuration, a reflection surface 41 a for reflecting the light beam L is formed on the surface of the main body portion 41 on the −Z direction side.
In addition, although it was set as aluminum vapor deposition here, the main-body part 41 may use the metal member with the high reflectance of visible region, and vapor-deposited the metal material with the high reflectance of visible region on the resin material. It may be a thing.

  As shown in FIGS. 4A to 4C, the housing 20 includes a first contact portion 23 that is a truncated cone-shaped recess provided at a position facing the first positioning portion 43, and a second positioning portion. And a second abutting portion 24 which is a trapezoidal groove-like concave portion provided at a position facing the portion 44.

As shown in FIG. 4A, the first contact portion 23 is in contact with the first positioning portion 43 in a fixed state where the reflection mirror 40 is attached to the housing 20. It becomes a fixed state.
The second contact portion 24 is a groove-like recess formed in parallel with the Y axis, and is in a state of being fixed to the second positioning portion 44 in a state of being in contact with the second positioning portion 44 in a fixed state. FIG. 4B is a view of the reflection mirror 40 viewed from the + Z direction in such a fixed state, and FIG. 4C is a YZ sectional view of the reflection mirror 40 viewed from the −X direction.

  A method for projecting an image in the image projection apparatus 100 having the above-described configuration will be described.

White light emitted from the light source 101 enters the spatial light modulation element 102 as a substantially parallel light beam L, and a color image is generated by the spatial light modulation element 102 that applies spatial modulation based on the control of the control unit 109. Information is given.
The light beam L that has been spatially modulated by the spatial light modulation element 102 passes through the lens unit 200 and is projected on the reflection mirror 40 as a projection image Q.
At the reflection mirror 40, the projection image Q is reflected and projected onto the projection surface 104.

  In such an image projection apparatus 100, particularly when the main body 41 has an aspherical shape, the accuracy of the image projected on the projection surface 104 depends on the attachment accuracy of the reflection mirror 40, specifically the incidence of the light beam L. It largely changes depending on the inclination and position of the reflecting surface 41a with respect to the direction.

Regarding the attachment of the reflective optical element such as the reflective mirror 40, adjustment is required in many items, and various structures have been considered.
For example, as shown in FIG. 6 as a comparative example, a positioning unit 48 for positioning is provided on the Y axis, which is the central axis of the projection image, and the positioning unit 48 and the virtual casing 20 ′ are in contact with each other. A structure in which the reflecting mirror 40 ′ is fixed to the positioning portion 48 by a fixing member such as a screw is conceivable.
However, when the positioning portion 48 is formed on the Y axis as in such a structure, the center position of the projection image Q and the main body portion 41 ′ can be easily aligned by rotating the positioning portion 48 as a center, while the reflection mirror 40 ′. It is considered that there is a problem that increases in the Y-axis direction.
As described above, when the reflecting mirror 40 ′ is enlarged in the vertical direction of the projection image Q, that is, in the Y-axis direction, there is a concern that the casing 20 ′ as an attachment target is also enlarged and so-called injury occurs.

Therefore, in the present embodiment, the first positioning portion 43 and the second positioning portion 44 are provided in the direction along the X direction.
The mounting operation in this embodiment will be described with reference to FIGS.

First, as shown in FIG. 5A, the first positioning portion 43, which is the positioning portion on the main reference side, is brought into contact with the first contact portion 23 to be in a temporarily determined state. In the temporarily determined state, the first positioning portion 43 is inserted into the concave portion of the first contact portion 23, so that the reflection mirror 40 is restricted from moving in the Z direction with respect to the housing 20, and is on the XY plane. Is supported in a rotatable state around the first positioning portion 43.
At this time, since the second contact portion 24 has a groove shape, there is a gap at least in the Y direction between the second contact portion 24 and the second positioning portion 44, and the groove-shaped second contact portion. 24, the second positioning portion 44 is held so as to be movable in the Y direction.
Therefore, the second contact portion 24 functions as a secondary reference side positioning portion when the first positioning portion 43 is used as the primary reference side positioning portion and the position is provisionally determined.
Note that the movable direction is determined by the gap formed between the second contact portion 24 and the second positioning portion 44, and thus, for example, between the second contact portion 24 and the second positioning portion 44. If there is a gap in the X direction, it can move in the X direction along with the Y direction.

Next, the position is adjusted so that the Y axis, which is the reference axis of the main body 41, passes through the center portion O of the projection image Q, and the fixing portion 45 is fixed by a fixing member such as a screw.
In this fixed state, as shown in FIG. 5B, the reflecting mirror 40 is restrained in the −Z direction by the fixing member. Therefore, the hemispherical second positioning portion 44 is formed on the second contact portion 24 that is a trapezoidal groove. It is positioned by abutting and being suppressed.
As already described, in the fixed state, the Y axis that is the reference axis of the main body 41 is parallel to the vertical direction of the projection image Q and coincides with the vertical axis that passes through the center of the projection image and is perpendicular to the longitudinal direction. Are arranged as follows.

  As described above, by providing the first positioning portion 43 and the second positioning portion 44 so as to be symmetric with respect to the Y axis along the X direction, the reflection mirror 40 maintains high fixing accuracy. However, it suppresses the enlargement of the Y direction compactly.

In the present embodiment, the second positioning unit 44 is positioned in a state where the position of the first positioning unit 43 is provisionally determined with respect to the housing 20 of the image projection device 100.
With this configuration, the center axis of the projection image Q and the Y axis, which is the reference axis of the main body 41, can be adjusted in the provisionally determined state, so the size in the Y direction can be increased in a compact manner while maintaining high fixing accuracy. Suppress.

In the present embodiment, the reflection mirror 40 has two fixing portions 45 provided along the Y direction with respect to each of the first positioning portion 43 and the second positioning portion 44.
With this configuration, the reflection mirror 40 and the housing 20 are fixed, and high fixing accuracy is maintained.

In the present embodiment, the first positioning portion 43 and the second positioning portion 44 are provided so as to protrude from the main body portion 41 along the longitudinal direction of the projection image Q, that is, the X direction. Further, the housing 20 includes a first contact portion 23 provided at a position facing the first positioning portion 43 and a second contact portion 24 provided at a position facing the second positioning portion 44. Have.
With this configuration, since the second positioning portion 44 and the second contact portion 24 are positioned in contact with the first positioning portion 43 in contact with the first contact portion 23, high fixing accuracy is maintained. However, it suppresses the enlargement of the Y direction compactly.

In the present embodiment, the first contact portion 23 is a truncated cone-shaped recess, and the second contact portion 24 is a trapezoidal groove extending in parallel to the Y direction.
With this configuration, since the second positioning portion 44 is held movably with respect to the second contact portion 24 even in the provisionally determined state, it is possible to suppress the increase in size in the Y direction in a compact manner while maintaining high fixing accuracy. .

  The preferred embodiments of the present invention have been described above. However, the present invention is not limited to the specific embodiments, and the present invention described in the claims is not specifically limited by the above description. Various modifications and changes are possible within the scope of the above.

  For example, the image projector is a single-plate color projector that provides color image information with a single liquid crystal panel, but is not limited thereto, and may be a three-plate color projector or a monochrome image projector. There may be.

In the present embodiment, the first contact portion has a truncated cone shape. However, the first contact portion may have a conical shape, or a hemispherical concave portion that fits into the first positioning portion.
In addition, a first positioning portion and a second positioning portion that are protrusions on the reflective optical element side are provided, and a first contact portion and a second contact portion that are recesses on the housing portion side of the opposing image projection device. Although provided, the combination of irregularities may be reversed.

  In the present embodiment, the second contact portion has a trapezoidal groove shape, but it may be simply a groove shape, and the second contact portion may be finely adjusted to be a hemisphere larger than the second positioning portion. It may be held as such.

  The effects described in the embodiments of the present invention are only the most preferable effects resulting from the present invention, and the effects of the present invention are limited to those described in the embodiments of the present invention. is not.

20 Case (Case) (Image Projector Body)
23 1st contact part 24 2nd contact part 40 Reflective type optical element (reflection mirror)
41 Reflector (body)
41a Reflective surface 42 Outer peripheral part (support part)
43 1st positioning part 44 2nd positioning part 100 Image projector 200 Lens unit L Incident light (light beam)
Q Projected image X Projected image longitudinal direction Y Reference axis (vertical axis)

Japanese Patent No. 5351520

Claims (4)

A reflection unit having a reflection surface symmetric with respect to a reference axis for reflecting an image projected from the image projection apparatus main body side toward the projection surface as a projection image;
A first positioning portion provided on the outer peripheral portion of the reflecting portion so as to protrude in a direction perpendicular to the reference axis, and for temporarily determining the attachment position of the reflective optical element with respect to the image projection apparatus main body side;
A second positioning portion that is provided to protrude to the opposite side of the first positioning portion across the reference axis, and that positions the attachment position of the reflective optical element with respect to the image projection apparatus main body side;
A reflective optical element. The reflective optical element according to claim 1,
A reflective optical element having a plurality of fixing portions provided along a direction parallel to the reference axis with respect to each of the first positioning portion and the second positioning portion. A reflective optical element for reflecting a light beam transmitted through a projection optical system formed by at least one lens toward a projection surface as a projection image;
A housing for holding the reflective optical element;
With
The reflective optical element is
A reflective portion comprising a reflective surface that is a curved surface from which the luminous flux is reflected;
A first positioning portion provided along the longitudinal direction of the projected image on the outer periphery of the reflecting portion;
A second positioning part provided on the opposite side of the first positioning part across a vertical axis passing through the center of the projection image and perpendicular to the longitudinal direction,
The housing includes a first abutting portion that temporarily contacts the first positioning portion and temporarily determines a position where the reflective optical element is held, and the first positioning portion and the first abutting portion. An image projection apparatus comprising: a second contact portion that contacts and positions the second positioning portion in a contact state. The image projector according to claim 3.
The first contact portion is a truncated cone-shaped recess,
The image projection apparatus according to claim 1, wherein the second contact portion is a groove portion extending along a direction parallel to the vertical axis.

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