JP2008139442A - Mirror attachment structure - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To appropriately adjust the attitude of an aspherical mirror without spending a long adjustment time. <P>SOLUTION: The curved mirror 13 is attached to a holding member 21 so that it can rotate by taking a first axis Xa as an axis parallel to an X axis in an XY plane, orthogonal to a Z axis as a base axis (mirror axis), as a rotational center, and the curved mirror 13 is held by the holding member 21 so that the attitude in terms of the rotating angle with the first axis Xa as the rotational center can be optionally changed by a first attitude adjustment means. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a mirror mounting structure (mechanism) used for an optical projection device, and more particularly to a mirror mounting structure for holding a curved mirror used for a projector (projector).

  Optical projection devices such as rear projectors and front projectors guide video light projected from a projection optical system to a screen by reflecting it with a curved mirror (projection mirror). The curved mirror used in this type of light projection device is generally an aspherical mirror such as a parabolic mirror having no spherical aberration so as to send reflected light in parallel to a distant place.

  Since the aspherical mirror is composed of a curved surface formed by rotating a predetermined noncircular curve such as a parabola around a predetermined base axis extending linearly, unlike a circular mirror, Since it has a unique mirror axis unique to the base axis of the rotating surface, highly accurate three-dimensional stereoscopic posture adjustment is required when the light projection device is assembled in order to reflect the image light in the correct direction.

On the other hand, conventionally, the mounting posture of the aspherical mirror can be adjusted by floatingly supporting the aspherical mirror at three points with respect to the holding member and individually adjusting the floating amount at each point. (For example, patent document 1).
JP 2002-228905 A

  However, in the three-point floating support, the floating amount adjustment of each support point affects all three geometric axes (three-dimensional coordinate axes) constituting the aspherical mirror when setting the attitude of the aspherical mirror. However, while the degree of freedom of adjustment is high, it is impossible to adjust only the angular posture around a specific coordinate axis of the aspherical mirror.

  For this reason, conventionally, it is necessary to repeatedly adjust the floating amount of each support point and to adjust the posture of the aspherical mirror by trial and error. For this reason, since a long adjustment time is required or the adjustment cannot be performed correctly, performance is sacrificed due to a distortion in the projected image caused by the image light reflected by the aspherical mirror.

  The present invention has been made to solve the above-described problems, and an object thereof is to provide a mirror mounting structure capable of appropriately adjusting the posture of an aspherical mirror without requiring a long adjustment time. Yes.

  The mirror mounting structure according to the present invention is the mirror mounting structure in which the curved mirror that reflects the image light projected from the projection optical system is mounted on the holding member, and the curved mirror is held so as to be rotatable about a predetermined axis. Mirror posture adjusting means is attached to the member and holds the curved mirror so as to be changeable to any rotation angle posture with the shaft as a rotation center.

  The mirror mounting structure according to the present invention is a mirror mounting structure in which a curved mirror that reflects video light projected from a projection optical system is mounted on a holding member. The reflecting surface of the curved mirror has a predetermined non-circular curve in a straight line. The curved mirror is formed by using a part of a curved surface formed when rotated about a predetermined base axis extending to the base axis, or the curved mirror intersects the base axis at a predetermined angle, or Arbitrary rotation angle posture about the first axis that is pivotable about a first axis that is parallel to an axis that intersects at a predetermined angle and that is pivotable about the first axis There is a first posture adjusting means for holding the curved mirror from the holding member so that the curved mirror can be changed.

In the mirror mounting structure according to the present invention, more preferably, the curved mirror is provided with a first engaging portion provided at two positions separated in the first axial direction, and an arrangement of the first engaging portion. And a second engaging portion provided at one location away from the portion in the rotational radius direction around the first axis, each of the first engaging portions being two of the holding member. Engaged with a first engaged portion provided at a location so as to be rotatable about the first axis and movable in the first axial direction;
The second engaging portion is displaceable in a rotational direction around the first axis with respect to a second engaged portion provided at one location of the holding member, but the first axis Engagement in a controlled manner in the direction.

  In the mirror mounting structure according to the present invention, more preferably, the first engaging portion is constituted by a cylindrical shaft member, and the first engaged portion is a V-groove that receives the first engaging portion. And a leaf spring member that presses the first engaging portion against the first engaged portion.

  More preferably, in the mirror mounting structure according to the present invention, a second axis that intersects at a predetermined angle with respect to a plane formed by the base axis and an axis that intersects the base axis at a predetermined angle is more preferably the center of rotation. And a second base for holding the holding member from the base in such a manner that the holding member can be changed to an arbitrary rotation angle posture around the second axis. Posture adjustment means.

  According to the mirror mounting structure of the present invention, one coordinate axis specified among the three geometric coordinate axes constituting the curved mirror, for example, an axis orthogonal to the mirror axis (base axis) of the aspherical mirror Only the posture angle (elevation posture) of the aspherical mirror around the (first axis) can be adjusted without changing the angle posture around other coordinate axes constituting the curved mirror. Thereby, the posture adjustment of the aspherical mirror can be appropriately performed without requiring a long adjustment time.

  One embodiment of a mirror mounting structure according to the present invention will be described with reference to the drawings.

  First, an example of the overall configuration of an optical projection device to which the mirror mounting structure according to the present invention is applied will be described with reference to FIG.

  This light projection device projects image light from the projector 11, and the image light is reflected by each of the curved mirror 13 and the plane mirror 15 and is generally projected onto a vertically arranged screen 17. The mirror mounting structure according to the present invention is applied to the curved mirror 13 mounting structure.

  Next, one embodiment of the curved mirror 13 used in the mirror mounting structure according to the present invention will be described geometrically with reference to FIG.

  The curved mirror 13 is an aspherical concave mirror. In this embodiment, the curved mirror 13 has a predetermined base axis that extends linearly, that is, a Z axis, for example, a parabola or a curve PL approximated to a parabola. It is formed as a parabolic mirror using a part of a curved surface formed when rotated about the center. In this case, the Z axis (base axis) is the mirror axis of the curved mirror 13.

  Here, three geometrical coordinate axes of the curved mirror 13 are defined. With the Z axis as the horizontal axis, at the apex (0 point) P1 of the parabola PL, the horizontal coordinate axis that is tolerance (orthogonal) perpendicular to the Z axis is the X axis, and the vertical coordinate axis that is tolerance (orthogonal) perpendicular to the Z axis is the Y axis To do. The Z axis, the X axis, and the Y axis are orthogonal to each other at the vertex P1.

  As shown in FIGS. 2 and 3, the curved mirror 13 is a position where the dimension in the longitudinal axis direction (Y-axis direction) is A1 and the X-axis (vertex P1) is biased upward as viewed in the XY plane. And a rectangular outer shape Ma having a lateral dimension (X-axis direction) of A5 with the Y-axis being a half intermediate position in the X-axis direction. The effective reflection area Mb of the curved mirror 13 has a dimension A3 that is smaller than A1 in the longitudinal axis direction (Y-axis direction), does not include the X-axis (vertex P1), and the Y-axis is a half intermediate position in the X-axis direction. As shown in FIG. 1, the horizontal dimension (X-axis direction) is a rectangle having a dimension A7 smaller than A5. The upper edge of the mirror parallel to the X axis is indicated by L1, and the lower edge of the mirror is indicated by L3.

  4 to 9 show one embodiment of a mirror mounting structure according to the present invention.

  The curved mirror 13 is a holding member that is rotatable about an axis that is orthogonal to the Z axis that is the base axis (mirror axis), that is, the first axis Xa that is parallel to the X axis and the XZ plane. 21 is attached. Details of the mounting structure will be described below.

  The curved mirror 13 serves as a first engaging portion on the first axis line Xa at two locations separated in the extending direction of the first axis line Xa, that is, on the left and right outer edges of the curved mirror 13 respectively. A cylindrical shaft member 29 is integrally provided. The two left and right shaft members 29 are the same axis line whose center axis line is on the first axis line Xa. Here, the shaft member 29 is in a portion close to the mirror upper edge L1.

  The holding member 21 has a bottom portion 23 and a pair of vertical support portions 25 provided vertically on the left and right sides of the bottom portion 23. V-grooves 27 extending in the left-right direction (extending direction of the first axis line Xa) are formed at the upper edge portions of the left and right vertical support portions 25 as first engaged portions. The left and right V-grooves 27 respectively receive the left and right shaft members 29 so as to be rotatable around the first axis Xa and movable in the extending direction of the first axis Xa.

  One end of a leaf spring 31 is fixed to the upper edge of each of the left and right vertical support portions 25. Each of the leaf springs 31 presses the shaft member 29 against the V groove 27 on the free end side.

  With this shaft support structure, the curved mirror 13 can be rotated around the first axis Xa without any backlash. This is important for optical instruments that require high mounting accuracy.

  The curved mirror 13 is integrally formed with an ear piece 33 on each of the left and right sides of a part away from the first axis Xa in the rotational radius direction around the first axis Xa, that is, a part near the mirror lower edge L3. Have. As shown in FIG. 8, through-holes 41 are opened in the two left and right ear pieces 33, respectively. In each through hole 41, stud bolts 39 screwed and fixed to the front portions of the vertical support portions 25 on both the left and right sides pass through with sufficient radial clearance in a loosely fitted state. A compression coil spring 43 is sandwiched between the head of the stud bolt 39 and the ear piece 33. The compression coil spring 43 biases the ear piece portion 33 toward the front portion of the vertical support portion 25.

  Female screw holes 35 are formed in the front portions of the left and right vertical support portions 25, and adjusting male screw members 37 are screw-engaged with the female screw holes 35. The adjustment male screw member 37 is in contact with the ear piece portion 33 at an end portion (tip portion) opposite to the screw engagement side with the female screw hole 35. The ear piece 33 is pressed against the tip of the adjustment male screw member 37 by the spring force of the compression coil spring 43.

  The adjustment male screw member 37 has a two-chamfered portion 37A, and is rotated by a spanner tool (not shown) engaged with the two-chamfered portion 37A, thereby changing the amount of protrusion from the front portion of the vertical support portion 25 and adjusting. The position of the ear piece portion 33 pressed by the spring force of the compression coil spring 43 with a protruding amount determined by the screwing amount of the male screw member 37 includes rattling as seen in FIGS. 7 and 8. Set without.

  In this way, the ear piece 33, the adjustment male screw member 37, the stud bolt 39, and the compression coil spring 43 can be changed to any rotation angle posture with the first axis Xa as the rotation center. The first posture adjusting means is held by the holding member 21.

  As shown in FIGS. 5 and 6, the curved mirror 13 is a part away from the arrangement part of the shaft member 29 in the rotational radius direction around the first axis line Xa, that is, a part near the mirror lower edge L3. The projecting piece 47 is integrally provided as a second engaging portion at one place in the central portion in the X-axis direction. A concave engaging portion 45 is formed as a second engaged portion at one location of the bottom 23 of the holding member 21.

  The protruding piece 47 can be displaced in the rotational direction around the first axis line Xa with the concave engagement portion 45, but engages in a manner in which movement of the first axis line Xa in the extending direction is restricted. ing. Thereby, the curved mirror 13 does not rattle and move in the extending direction of the first axis line Xa (the same direction as the X-axis direction) with respect to the holding member 21.

  By adjusting the screwing amount of the adjusting male screw member 37 described above, the curved mirror 13 is rotated about the X axis orthogonal to the Z axis that forms the base axis (mirror axis) and the first axis Xa that is an axis parallel to the ZX plane. And can be stably held in an arbitrary rotation angle posture with the first axis Xa as the rotation center.

  As a result, of the three geometric solid coordinate axes constituting the curved mirror 13, the posture angle (elevation posture) of the curved mirror 13 around the first axis Xa orthogonal to the mirror axis (base axis = Z axis) is set. ) Can be accurately adjusted without changing the angular orientation around the other coordinate axes (Z-axis and Y-axis) of the solid coordinate axis constituting the curved mirror 13.

  In the rotation angle adjustment around the first axis Xa of the curved mirror 13, the Z axis and the first axis Xa are in an invariable orthogonal relationship, and the curved mirror 13 is in the first axis Xa with respect to the holding member 21. In the extending direction, the mirror axis (base axis = Z axis) is maintained in the YZ plane.

  Thereby, the posture adjustment of the curved mirror 13 which is an aspherical mirror can be appropriately performed without requiring a long adjustment time.

  The curved mirror 13 is restricted from moving in the extending direction of the first axis line Xa by the engagement of the projecting piece 47 and the concave engaging portion 45 at one place away from the arrangement site of the shaft member 29, and the left and right shaft members Since the engaging portion between the groove 29 and the V-groove 27 can move in the extending direction of the first axis Xa, the first axis Xa of the curved mirror 13 due to temperature change without changing the mirror axis position. The thermal deformation in the extending direction is released.

  Thereby, even if a temperature change occurs, the optical axis position of the curved mirror 13 does not change and the optical characteristics are not deteriorated due to the thermal deformation of the curved mirror 13. There is no distortion.

  Note that the engagement between the projecting piece 47 and the concave engagement portion 45 is not an engagement relationship that restrains the thermal deformation of the curved mirror 13 in the Y-axis direction, so the thermal deformation of the curved mirror 13 in the Y-axis direction is also released. .

  As shown in FIGS. 5, 6, and 9, the holding member 21 is disposed on a base 51 by an optical chassis or the like, and is held with a vertical shaft member 53 provided on the holding member 21 on the base 51. A predetermined angle with respect to the XZ plane formed by the base shaft (Z-axis) and the X-axis intersecting at right angles with the base shaft by the pivotable fitting with the bearing hole 55 provided in the bottom 23 of the member 21. The second axis CL (see FIG. 7) intersecting with the base 51 can be swung about the rotation center.

  The holding member 21 rotates about the second axis CL around the vertical axis perpendicular to the plane parallel to the XZ plane in the rotating attitude around the first axis Xa of the curved mirror 13 where the Y axis is vertical. Rotation.

  As the second attitude adjusting means, elongated hole-shaped bolt mounting holes 57 (see FIG. 4) are formed at a plurality of locations on the holding member 21, and fastening bolts (not shown) inserted into the bolt mounting holes 57 are provided. Each of the holding members 21 can be changed to an arbitrary rotation angle posture with the second axis CL as the rotation center by screw engagement with a screw hole (not shown) formed in each of the bases 51. Hold more.

  Thus, the curved mirror 13 around the second axis CL can be accurately adjusted without changing the posture angle alone, and without changing the angular posture around the other coordinate axes (Z axis and X axis) constituting the curved mirror 13. Can be adjusted.

  The shaft member 29 may be provided on the X axis. In this case, the curved mirror 13 is rotated around the X axis instead of the first axis Xa, and the rest is the same as the case of rotating around the first axis Xa.

1 is a layout diagram illustrating an example of the overall configuration of an optical projection device to which a mirror mounting structure according to the present invention is applied. It is explanatory drawing explaining geometrically one embodiment of the curved mirror used for the mirror attachment structure by this invention. It is a figure of the curved mirror of the III direction arrow of FIG. It is a perspective view which shows one Embodiment of the mirror attachment structure by this invention. FIG. 5 is a view taken in the direction of arrow V in FIG. 4. It is an enlarged view of VI part of FIG. It is a VII arrow line view of FIG. It is an expanded sectional view by line VIII-VIII of FIG. It is a perspective view which shows the lower attachment part of one Embodiment of the mirror attachment structure by this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 11 Projector 13 Curved surface mirror 15 Plane mirror 17 Screen 21 Holding member 23 Bottom part 25 Vertical support part 27 V groove 29 Shaft member 31 Leaf spring 33 Ear piece part 37 Adjustment male screw member 39 Stud bolt 43 Compression coil spring 45 Concave engaging part 47 Projection Piece 51 Base 53 Vertical shaft member 55 Bearing hole
57 Bolt mounting hole

Claims (5)

In the mirror mounting structure for mounting the curved mirror that reflects the image light projected from the projection optical system to the holding member,
The curved mirror is attached to the holding member so as to be rotatable about a predetermined axis as a rotation center,
A mirror mounting structure comprising mirror posture adjusting means for holding the curved mirror so as to be changeable to an arbitrary rotation angle posture with the shaft as a rotation center. In the mirror mounting structure for mounting the curved mirror that reflects the image light projected from the projection optical system to the holding member,
The reflecting surface of the curved mirror is formed using a part of a curved surface formed when a predetermined non-circular curve is rotated around a predetermined base axis extending linearly,
The holding member is pivotable about a first axis that is an axis parallel to an axis that intersects the base axis at a predetermined angle or that intersects the base axis at a predetermined angle. Attached to the
A mirror mounting structure comprising first posture adjusting means for holding the curved mirror from the holding member so as to be changeable to an arbitrary rotation angle posture with the first axis as a rotation center. In the mirror mounting structure according to claim 2,
The curved mirror includes a first engagement portion provided at two locations separated in the first axial direction, and a turning radius around the first axis from the arrangement site of the first engagement portion. A second engagement portion provided at one location away from the direction,
The first engaging portion is rotatable about the first axis and moved in the first axial direction to first engaged portions provided at two locations of the holding member, respectively. Engaging possible,
The second engaging portion is displaceable in a rotational direction around the first axis with respect to a second engaged portion provided at one location of the holding member, but the first axis A mirror mounting structure characterized by engaging in a controlled manner in a direction. In the mirror mounting structure according to claim 3,
The first engaging portion is constituted by a cylindrical shaft member, the first engaged portion is constituted by a V-groove that receives the first engaging portion, and further, the first engaging portion A mirror mounting structure comprising a leaf spring member that presses against the first engaged portion. In the mirror mounting structure according to any one of claims 2 to 4,
A base that rotatably supports the holding member about a second axis that intersects at a predetermined angle with respect to a plane formed by the base and an axis that intersects the base at a predetermined angle; Have
2. A mirror mounting structure comprising second posture adjusting means for holding the holding member from the base so as to be changeable to an arbitrary rotation angle posture with the second axis as a rotation center.

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