JP2017227762A - Image projection device - Google Patents

Abstract

An object of the present invention is to improve the resolution of a projection image on a projection surface caused by an assembly position error of a reflecting mirror. A projection image light generated by an image generation device such as a DMD (26) based on image data using light from a light source passes through a projection lens (32), and a curved mirror (44) having a curved mirror surface receives the projection image light that has passed through a projection lens (32). In an image projection apparatus such as the projector 1 that forms an image on the projection surface 101 by reflecting a reflecting mirror such as a reflecting mirror, a holding member such as a projection housing 45 that holds the reflecting mirror and the optical axis position of the light incident on the reflecting mirror are reflected. and an adjustment mechanism such as an adjustment cam pin 71 for displacing the retainer member to vary over the surface. [Selection drawing] Fig. 8

Description

  The present invention relates to an image projection apparatus.

  Conventionally, projection image light generated by an image generation element based on image data using light from a light source passes through a projection lens, and the projection image light that has passed through is reflected by a reflecting mirror of a curved mirror surface to be reflected on the projection surface. An image projection apparatus for forming an image is known.

  For example, Patent Document 1 discloses an image projection apparatus, in which a projection image light generated by an image generation element is reflected by a plane mirror, and the reflected light is projected by a curved mirror that is a reflecting mirror having a curved mirror surface. A short focus type image projection apparatus that is reflected on the screen is disclosed. In the image projection apparatus, parallel to the optical axis of the projection image light toward the projection plane, around the first axis parallel to the intersection line of the projection plane and the horizontal plane, around the second axis parallel to the vertical axis. An adjustment mechanism for rotating the image projection apparatus main body is provided around each third axis. Then, when the entire projected image on the projection surface is a quadrangle, look at the outer peripheral outline frame line that is a quadrilateral frame line that is the boundary line between the projected image and its surroundings, and above and below the outer peripheral outline frame line The image projector main body is rotated around the first axis so that the lengths are the same. Further, the image projection apparatus main body is rotated around the second axis so that the left and right lengths of the outer peripheral outline frame line are the same. Further, when the projected image is tilted, the image projection apparatus body is rotated around the third axis so that the tilt of the projected image within the projection plane is corrected. As described above, the distortion of the projected image on the projection surface is corrected.

Normally, according to the short focus type image projection apparatus, if the optical element in the image projection apparatus is assembled at a target position, when the image projection apparatus is arranged at a predetermined position with respect to the projection surface, as designed. Is projected onto the projection surface. If the accuracy of the assembly position of the curved mirror that reflects and projects the projected image on the projection surface is poor, and the optical axis position of the light incident on the curved mirror is deviated from the center of the reflective surface of the curved mirror, the projection surface The imaging position of the upper projection image deviates from the target position. As a result, the resolution of the projected image may be deteriorated.
This problem is not limited to the short focus type image projection apparatus, but may also occur in the long focus type image projection apparatus.

  In order to solve the above-described problems, the present invention provides a projection mirror in which projection image light generated by an image generation element based on image data using light from a light source passes through a projection lens, and the projection image light that has passed through the curved mirror surface. In the image projection apparatus that reflects on the reflecting mirror and forms an image on the projection surface, the holding member that holds the reflecting mirror and the holding so that the optical axis position of the light incident on the reflecting mirror changes on the reflecting surface. And an adjusting mechanism for displacing the member.

  According to the present invention, it is possible to obtain a specific effect that the resolution of the projected image on the projection surface due to the assembly position error of the reflecting mirror can be improved.

The perspective view which shows the projector and projection surface which concern on this embodiment. (A) is a perspective view explaining the inside of a projector when it sees from the arrow A of FIG. 1, (b) is a perspective view explaining the inside of a projector when it sees from the arrow B of FIG. FIG. 2 is a schematic perspective view showing an internal configuration of a projector. The perspective view which shows a projection optical unit, an optical unit, an illumination unit, and a projection image generation unit. The figure explaining the optical path of the light in an illumination unit. The schematic diagram explaining the holding structure of a reflective mirror. The fragmentary perspective view explaining the holding structure of this embodiment. The top view of FIG.

Hereinafter, an embodiment of a projector as an image projection apparatus to which the present invention is applied will be described.
FIG. 1 is a perspective view showing a projector 1 and a projection surface 101 such as a screen according to the present embodiment. The projector 1 will be described by taking a short focus type as an example. In the following description, the normal direction of the projection plane 101 is the X direction, the short axis direction (vertical direction) of the projection plane is the Y direction, and the long axis direction (horizontal direction) of the projection plane 101 is the Z direction.

  As shown in FIG. 1, a transmissive glass 11 from which a projection image P is emitted is provided on the upper surface of the projector 1, and the projection image P emitted from the transmissive glass 11 is projected onto a projection surface 101 such as a screen. . An operation unit 12 for the user to operate the projector 1 is provided on the upper surface of the projector 1. A focus lever 13 for adjusting the focus is provided on the side surface of the projector 1.

2A and 2B are perspective views for explaining the inside of the projector. FIG. 2A is a perspective view seen from an arrow A in FIG. 1, and FIG. 2B is a perspective view seen from an arrow B in FIG.
As shown in FIGS. 2A and 2B, an optical engine 14 and a PFC (Power Factor Correction) power supply board unit 15 are arranged on the upper side of the projector. As shown in FIG. 2A, a printer circuit board 16 is disposed below the optical engine 14, and a ballast power supply unit 17 that stably supplies power to the light source of the light source unit is disposed below the PFC power supply board unit 15. Is arranged. Further, as shown in FIG. 2B, a light source unit 60 including a high-pressure mercury lamp, a laser, an LED light source, and the like is disposed below the PFC power supply board unit 15.

FIG. 3 is a schematic perspective view showing the internal configuration of the projector 1.
As shown in FIG. 3, the projection image generation unit 10, the illumination unit 20, the optical unit 30, and the projection optical unit 40 are arranged side by side in the Y direction in the drawing in a direction parallel to the projection surface and the image plane of the projection image. Yes. Further, a light source unit 60 is disposed on the right side of the illumination unit 20 in the drawing.

FIG. 4 is a perspective view showing the projection optical unit 40 together with the optical unit 30, the illumination unit 20, and the projection image generation unit 10.
As shown in FIG. 4, the projection optical unit 40 also includes a transmissive glass 41 for transmitting the light image reflected from the curved mirror and protecting the optical system components in the apparatus. The transmission glass 41 is held by one glass pressing member 42 at each of both ends in the Z direction.

FIG. 5 is a diagram for explaining an optical path of light in the illumination unit 20.
The color wheel 21 has a disk shape and is fixed to the motor shaft of the color motor 21a. The color wheel 21 is provided with filters such as R (red), G (green), and B (blue) in the rotation direction. The white light collected by the reflector provided in the holder of the light source unit reaches the peripheral end portion of the color wheel 21 through the emission window. The white light that has reached the peripheral edge of the color wheel 21 is separated into R, G, and B light in a time-sharing manner by the rotation of the color wheel 21.

  The light separated by the color wheel 21 enters the light tunnel 22. The light tunnel 22 has a rectangular tube shape, and the inner peripheral surface thereof is a mirror surface. The light that has entered the light tunnel 22 is emitted toward the relay lens 23 that is reflected by the inner peripheral surface of the light tunnel 22 a plurality of times and is condensed while correcting the longitudinal chromatic aberration of the light.

  The light passing through the light tunnel 22 passes through the two relay lenses 23, is reflected by the cylinder mirror 24 and the concave mirror 25, and is on the image generation surface of a DMD (Digital Micro-mirror Device) 26 which is a micro drive mirror device. The light is focused and imaged.

  A plurality of movable micromirrors are arranged in a lattice pattern on the image generation surface of the DMD 26. Each micromirror can incline the mirror surface by a predetermined angle around the twist axis, and can have two states of “ON” and “OFF”. When the micromirror is “ON”, the light from the light source is reflected toward the projection lens as indicated by an arrow L2 in FIG. When “OFF”, as shown by an arrow L1 in FIG. 5, light from the light source is reflected toward the OFF light plate held on the side surface of the illumination bracket. Therefore, by driving each mirror individually, light projection can be controlled for each pixel of the image data, and an image can be generated.

Next, features of the present invention will be described.
FIG. 6 is a schematic diagram for explaining a holding structure of the reflecting mirror.
As shown in FIG. 6, the luminous flux of the projection image that has passed through the projection lens 32 held by the lens barrel 31 includes a flat mirror 43 disposed on the projection surface side and a curved mirror 44 serving as a reflecting mirror disposed on the user side. Then, the light passes through the transmissive glass 41 and is projected onto the projection surface. The flat mirror 43 has a rectangular shape having a short side and a long side, and is held by being pressed against a prescribed surface of the projection housing 45 by a pressing member.

  The curved mirror 44 has a concave reflecting surface. Outside the reflection area on the reflection surface side of the projection housing 45, which is a holding member that holds the curved mirror 44, there is a protrusion 46 that is in contact with the groove portion 48 of the reflector holding bracket 47, which is another holding member, and has an arcuate tip. Is formed. The projecting portion 46 as the turning shaft portion is provided on the left and right center lines above the projection housing 45 when viewed from the reflection surface of the curved mirror 44, and has a turning shaft shape capable of pivoting the axis.

  Further, as shown in FIG. 3, adjustment screws 45a and 45b are respectively provided below the projection housing 45 at positions that are symmetric with respect to the center line of the projection housing 45 provided with the projections 46. ing. By turning the adjusting screws 45a and 45b, the direction of the reflecting surface of the curved mirror 44 assembled to the projection housing 45 is turned around the projection 46. The projection surface shape is adjusted by an adjustment movable portion 49a that is movable around the pivot axis and an adjustment movable portion 49b that adjusts the height direction position of the protrusion 46.

  However, since it is limited to partial adjustment of the projected image shape on the projection surface, it is not sufficient to adjust to a better projected image shape. For example, if the accuracy of the assembly position of the curved mirror is poor, the center of the reflection surface of the curved mirror after assembly may be shifted from the center of the lens surface of the projection lens. In that case, the optical path length between the left part and right part of the reflection surface when viewed from the reflection surface side of the curved mirror and the left part and right part of the projection image on the projection surface corresponding to each part is designed. Each value varies. As a result, the image formation position of the left part and the right part of the projection image is shifted, and the resolution of the projection image is deteriorated. After assembling the curved mirror, there is a problem that it is difficult to satisfactorily correct the resolution of the projected image on the projection surface. Hereinafter, this embodiment for solving this problem will be described.

FIG. 7 is a partial perspective view illustrating the holding member of the curved mirror according to the present embodiment. FIG. 8 is a plan view of FIG.
As shown in FIGS. 7 and 8, a relay bracket 50 as a relay member is interposed between the projection housing 45 and the reflecting mirror holding bracket 47. The relay bracket 50 is formed with an adjustment long hole 50a into which an adjustment cam pin 71 having an eccentric cam is inserted, and a guide long hole 50b into which the guide pin 72 is inserted. The adjustment cam pin 71 is rotatably provided on the projection housing 45, and the guide pin 72 is fixed to the projection housing 45. Furthermore, a screw hole for screwing the relay bracket 50 to the projection housing 45 is formed after adjustment described later.

  The reflecting mirror holding bracket 47 is formed with an adjustment long hole 47a into which an adjustment cam pin 73 having an eccentric cam is inserted, and a guide long hole 47b into which the guide pin 74 is inserted. The adjustment cam pin 73 is rotatably provided on the relay bracket 50, and the guide pin 74 is fixed to the relay bracket 50. Further, a screw hole for screwing the reflector holding bracket 47 to the relay bracket 50 after the adjustment is formed.

  Next, the adjustment mechanism of the present embodiment will be described. For example, when the adjustment cam pin 73 as the adjustment mechanism is rotated while viewing the projection image on the projection surface, the reflector holding bracket 47 is shown in FIG. Translational displacement in the direction of arrow X. Further, the guide pin 74 fixed to the relay bracket 50 is in contact with the inner wall surface of the hole in the long side portion of the guide long hole 47 b of the reflector holding bracket 47. Therefore, when the adjustment cam pin 71 is rotated, the reflector holding bracket 47 and the relay bracket 50 are displaced in translation with respect to the projection housing 45 in the direction of arrow Y in FIG. The translation direction of the arrow X in FIG. 8 is perpendicular to the translation direction of the arrow Y in FIG. The projection plane shape is adjusted by using the adjustment mechanism of the adjustment movable part 49a and the adjustment movable part 49b together.

  After the above adjustment and the curved mirror is assembled in the target assembly position, the distortion and resolution of the projected image are improved, and then the screw between the projection housing 45 and the relay bracket 50 is screwed. It fixes by fastening and it fixes between the reflector holding bracket 47 and the relay bracket 50 by screw fastening. Note that the position adjustment amount in translational displacement can be handled by changing the specification of the adjustment cam pin from the adjustment amount required for optical design and setting of component tolerances. Further, the adjustment cam pin may be formed as a jig used only when adjusting the posture of the curved mirror holding member, or may be held and fixed as a component of the projection optical unit.

What was demonstrated above is an example, and there exists an effect peculiar for every following aspect.
(Aspect A)
Projection image light generated by an image generation element such as DMD 26 based on image data using light from the light source passes through the projection lens 32, and the reflected projection light such as a curved mirror 44 having a curved mirror surface passes through the projection image light. In the image projection apparatus such as the projector 1 that is reflected by the projection surface 101 and formed on the projection surface 101, the holding member such as the projection housing 45 that holds the reflection mirror and the optical axis position of the light incident on the reflection mirror are the reflection surface. And an adjusting mechanism such as an adjusting cam pin 71 for displacing the holding member so as to change above.
According to this aspect, when the optical axis position of the light incident on the reflecting mirror is shifted from the center of the reflecting surface of the reflecting mirror assembled to the holding member, the adjusting mechanism is used to adjust the light incident on the reflecting mirror. The holding member is displaced so that the optical axis position coincides with the center of the reflecting surface of the reflecting mirror assembled to the holding member. Specifically, the reflection mirror is moved in the width direction or height direction of the reflection mirror in the reflection surface when viewed from the reflection surface side, and the optical axis position of the light incident on the reflection mirror and the reflection assembled to the holding member Match the center of the reflecting surface of the mirror. Thereby, the resolution of the projection image on the projection surface due to the reflection mirror mounting position error can be improved.

(Aspect B)
In (Aspect A), a pivot shaft such as a protrusion 46 having a pivot shaft shape capable of pivoting on an axis is provided on the left and right center lines of the holding member, and is held by the holding member around the pivot shaft. The direction of the reflecting surface of the reflecting mirror is swiveled.
According to this aspect, when viewed from the reflecting surface side of the reflecting mirror, the direction of the reflecting surface of the reflecting mirror assembled to the holding member is swung left and right. Accordingly, for example, when the direction of the reflecting surface of the reflecting mirror is swung to the left, the left portion of the reflecting surface of the reflecting mirror is moved away from the preceding plane mirror, and the right portion of the reflecting surface of the reflecting mirror approaches the plane mirror. As a result, the optical path length between the left portion of the reflecting surface of the reflecting mirror and the reflecting surface portion of the reflecting mirror corresponding to that portion becomes longer, and the reflecting portion of the reflecting surface of the reflecting mirror and the right portion of the reflecting surface of the reflecting mirror is reflected. The optical path length between the surface portions is shortened. In this way, the imaging position of the reflecting mirror can be adjusted by swinging the direction of the reflecting surface of the reflecting mirror after assembling to the holding member to the left and right. Therefore, even after the reflecting mirror is assembled to the holding member with an error with respect to the target assembling position, the imaging positions of the left and right portions of the projected image on the projection surface reflected by the reflecting mirror are targeted. The position can be corrected.

(Aspect C)
In (Aspect A) or (Aspect B), the adjustment mechanism has two adjustment members, and the linear displacement direction of one adjustment member and the linear displacement direction of the other adjustment member are different from each other. It is a feature.
With such a configuration, it is possible to adjust by moving straightly and individually in different directions with a simple configuration. Thereby, the adjustment can be easily performed without affecting the amount of linear displacement.

(Aspect D)
In (Aspect C), the rectilinear displacement direction of the one adjusting member and the rectilinear displacement direction of the other adjusting member are perpendicular to each other.
With this configuration, the optical path length between the reflecting mirror and the projection surface can be changed, and at least the lower side length of the projection image can be adjusted more easily.

(Aspect E)
In any one of (Aspect A) to (Aspect D), the adjustment mechanism uses an eccentric cam.
With this configuration, the two adjustment members can be linearly displaced in different directions within the horizontal plane with respect to the holding member with a simple configuration.

DESCRIPTION OF SYMBOLS 1 Projector 10 Image formation unit 11 Transmission glass 12 Operation part 13 Focus lever 14 Optical engine 15 PFC power supply board unit 16 Printer circuit board 17 Ballast power supply unit 18 Light source unit 20 Illumination unit 21 Color wheel 21a Color motor 22 Light tunnel 23 Relay lens 24 Cylinder mirror 25 Concave mirror 26 DMD
30 Optical unit 31 Lens barrel 32 Projection lens 40 Projection optical unit 41 Transmission glass 42 Glass holding member 43 Flat mirror 44 Curved mirror 45 Projection housing 45a Adjustment screw 45b Adjustment screw 46 Projection 47 Reflector holding bracket 47a Adjustment long hole 47b Guide Slot 48a first adjustment movable part 49b second adjustment movable part 50 relay bracket 50a adjustment long hole 50b guide long hole 60 light source unit 71 adjustment cam pin 72 guide pin 73 adjustment cam pin 74 guide pin 101 projection surface

Japanese Patent No. 5704443

Claims (5)

The projection image light generated by the image generation element based on the image data using the light from the light source passes through the projection lens, and the projected image light that has passed through is reflected by the reflecting mirror of the curved mirror surface to form an image on the projection surface. In the image projection device to be
A holding member for holding the reflecting mirror;
An image projection apparatus comprising: an adjustment mechanism that displaces the holding member so that an optical axis position of light incident on the reflecting mirror changes on the reflecting surface. The image projection apparatus according to claim 1,
A pivot shaft having a pivot shaft shape capable of pivoting on the left and right center lines of the holding member is provided, and the direction of the reflecting surface of the reflecting mirror held by the holding member is pivoted around the pivot shaft. An image projection apparatus characterized by moving. The image projection apparatus according to claim 1,
The adjustment mechanism has two adjustment members, and the linear displacement direction of one adjustment member and the linear displacement direction of the other adjustment member are different from each other. The image projection apparatus according to claim 3.
The image projecting apparatus according to claim 1, wherein the linear displacement direction of the one adjustment member and the linear displacement direction of the other adjustment member are orthogonal to each other. The image projection apparatus according to any one of claims 1 to 4,
An image projecting apparatus according to claim 1, wherein the adjusting mechanism uses an eccentric cam.

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