JP2015152686A - image projection device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a short projection image projection device that allows a simple configuration to correct distortion of a projection image.SOLUTION: An image projection device includes an image display element 15 having light from a light source made incident and emanating an optical image modulated on the basis of an image signal, and a projection optical system 10 projecting the optical image emanated from the image display element 15 on a screen 21, in which the projection optical system 10 includes a lens group 11, and a plane surface mirror 12 and curve mirror 13 that are arranged behind the lens group 11 along an optical axis, and the image projection device comprises: a reflection angle change mechanism that changes a reflection angle of the plane surface mirror 12 in order to adjust a location of an image projected on the screen 21; and a control unit 25 that controls the image signal to electrically correct distortion of the projection image on the screen 21 when the reflection angle of the plane surface mirror 12 is changed by the reflection angle change mechanism.

Description

  The present invention relates to an image projection apparatus such as a liquid crystal projector.

  In recent years, image projection apparatuses such as liquid crystal projectors have been improved in the resolution of liquid crystal panels, the improvement in brightness accompanying the increase in efficiency of light source lamps, and the reduction in price. In addition, compact and lightweight image projection devices using DMD (Digital Micro-mirror Device) have become widespread, and such image projection devices have been widely used not only in offices and schools but also at home. Yes.

  In recent years, there has been a demand for a reduction in size and weight of the projection apparatus body and a reduction in projection distance (hereinafter referred to as short projection). In order to satisfy this demand, a projection optical system using a reflective imaging optical system is required. Has been developed, and an image projection apparatus equipped with this projection optical system has been realized. For example, an image projection apparatus has been proposed in which a free-form surface mirror and a plane mirror are provided in a reflective imaging optical system, thereby reducing the size and weight of the projection apparatus main body and shortening the projection (see Patent Document 1).

  In addition, an image projection apparatus has been proposed in which a flat imaging mirror and a plurality of free-form surface lenses are provided in a reflective imaging optical system, thereby reducing the size and weight of the projection apparatus body and shortening the projection. In this image projection apparatus, the position of an image projected obliquely from the projection apparatus main body onto the screen can be adjusted by moving a plurality of free-form surface lenses in conjunction with each other on the optical axis (see Patent Document 2). .

  In the image projection apparatuses of Patent Document 1 and Patent Document 2, short projection can be easily realized by using a free-form surface mirror or a free-form surface lens together with a plane mirror. However, in any of the image projection apparatuses, the height of the projection image may be limited depending on the installation location of the projection apparatus main body, and in this case, there is a disadvantage that the projection image on the screen is distorted.

  Note that there has been proposed an image projection apparatus that automatically corrects distortion of a projected image when an image projection position on a screen is to be adjusted. In this image projection apparatus, when the projection apparatus main body is tilted, the projection direction from the projection apparatus main body (for example, the inclination of the projection lens, etc.) is detected, and distortion of the projected image is automatically corrected ( (See Patent Document 3).

  By the way, even if it is going to apply the technical matter which detects the projection direction in patent document 3, and correct | amends distortion of a projected image to the image projection apparatus which aimed at short projection like patent document 1 and patent document 2, it is projected. Problems arise when the device body is tilted. That is, the short projection image projection apparatus has high installation sensitivity of the projection apparatus main body, and when the projection apparatus main body is tilted, the distortion of the projected image becomes very large. In addition, a sensor for detecting the tilt of the projection apparatus main body needs to be highly accurate, which not only incurs high costs but also reacts to slight fluctuations in the projection apparatus main body and may cause unintended correction. There is.

  An object of the present invention is to provide a short projection image projection apparatus that can correct distortion of a projection image with a simple configuration.

  In order to solve the above-described problems, the present invention provides a light modulating unit that emits an optical image that is modulated based on an image signal when light from a light source is incident thereon, and an optical image that is emitted from the light modulating unit on a screen. A projection optical system for enlarging and projecting, wherein the projection optical system is an image projection device including a lens group and a reflecting mirror disposed behind the lens group along an optical axis, A reflection angle changing mechanism for changing a reflection angle of the reflection mirror to adjust the position of the projected image; and the image signal is controlled when the reflection angle of the reflection mirror is changed by the reflection angle changing mechanism. And image distortion correction means for electrically correcting distortion of the projected image on the screen.

  According to the present invention, when the reflection angle of the reflection mirror is changed by the reflection angle changing mechanism, the image distortion correction unit controls the image signal to electrically correct the distortion of the projected image on the screen. Thereby, in the short projection image projection apparatus, the projection height can be easily adjusted with a simple configuration.

It is a figure which shows the structure of an image display element and a projection optical system among image projection apparatuses. It is a figure which shows a mode when an image is projected on a screen with the projection optical system of FIG. It is a figure which shows the detailed structure of the projection optical system of FIG. It is a figure which shows the reflection angle change mechanism for changing the reflection angle of a plane mirror. It is a figure explaining a mode that the position of the projection image on a screen is performed by changing the reflection angle of a plane mirror. It is a figure explaining a mode that distortion of a projection picture after changing a reflective angle of a plane mirror is electrically amended. It is a figure which shows a mode that the reflection angle change of a plane mirror is performed with an image position adjustment lever. It is a block diagram of an image projection apparatus that automatically and electrically corrects distortion of a projected image. It is a block diagram of an image projection apparatus that manually and manually corrects distortion of a projected image. FIG. 9 is a schematic configuration diagram of an image projection apparatus according to a second embodiment that also controls a focus mechanism. 10 is a schematic configuration diagram of an image projection apparatus according to a third embodiment and provided with one curved mirror. FIG. FIG. 10 is a configuration diagram of an image projecting apparatus according to a fourth embodiment and including an illumination optical system. FIG. 10 is a configuration diagram of an image projecting device including a lighting optical system according to a modification of the fourth embodiment.

  Embodiments of the present invention will be described below with reference to the drawings.

Example 1
FIG. 1 is a diagram showing a projection optical system that forms part of the image projection apparatus. As shown in FIG. 1, the projection optical system 10 includes a lens group 11 composed of a plurality of lenses, and a reflection composed of a plane mirror 12 and a curved mirror 13 disposed on the rear side of the lens group 11 along the lens optical axis L. And a mirror 14. Further, an image display element 15 is disposed as a light modulation means on the front side of the lens group 11 along the lens optical axis L. Here, the plane mirror 12 has a rectangular shape, and the curved mirror 13 is formed in a rotationally symmetric spherical shape, a rotationally symmetric aspherical shape, or a rotationally asymmetric free curved surface shape.

  The image display element 15 displays an image (optical image) according to an image signal given from the outside. The image display element 15 is irradiated with illumination light from an illumination optical system (not shown), and the illumination light is two-dimensionally intensity-modulated by the image displayed on the image display element 15 and enters the lens group 11. To do. Thereafter, the illumination light is reflected by the reflection mirror 14 (the plane mirror 12 and the curved mirror 13). That is, the optical path of the illumination light is folded back by the plane mirror 12, enters the curved mirror 13, and is reflected by the curved mirror 13. The illumination light reflected by the curved mirror 13 is projected as an enlarged image of the image display element 15 on a screen (not shown).

  FIG. 2 shows a schematic configuration of an image projection apparatus (projector) 20 on which the projection optical system 10 of FIG. 1 is mounted. In FIG. 2, the image forming light beam R by the projection optical system 10 is irradiated on the screen 21, and an enlarged image is displayed on the screen 21. A dustproof glass 22 is disposed between the curved mirror 13 of the reflection mirror 14 and the screen 21.

  FIG. 3 shows a state in which the image display element 15, the lens group 11, and the reflection mirror 14 are arranged in the housing 30. As shown in FIG. 3, the lens group 11 is housed in a stepped lens barrel 31 having a small diameter portion 31 </ b> A and a large diameter portion 31 </ b> B. The lens barrel 31 extends along the lens optical axis L in the housing 30. It is arranged at a substantially central part. The image display element 15 is disposed on the side of the housing 30 close to the small diameter portion 31 </ b> A of the lens barrel 31. The housing 30 is formed with a smaller cross section (cross section perpendicular to the lens optical axis L) in the portion 30A where the image display element 15 is disposed than in the portion 30B where the lens barrel 31 is disposed.

  In addition, the reflecting mirror 14 is disposed on the side of the housing 30 close to the large diameter portion 31B of the lens barrel 31. The housing 30 has a larger cross section (cross section perpendicular to the lens optical axis L) in the portion 30C where the reflecting mirror 14 is disposed than in the portion 30B where the lens barrel 31 is disposed. And the dust-proof glass 22 is provided in the front end surface of the part in which the reflective mirror 14 is arrange | positioned, and dust etc. do not penetrate | invade into the inside of the said part 30C from the outside.

  Of the reflecting mirrors 14, the plane mirror 12 is disposed such that the reflecting surface thereof is inclined (approximately 45 degrees with respect to the lens optical axis L) toward the end surface of the large-diameter portion 31 </ b> B of the lens barrel 31. The plane mirror 12 is attached to the housing 30 via a reflection angle changing mechanism 32. In the present embodiment, as shown in FIG. 3, the housing 30 is also formed obliquely toward the end surface of the large-diameter portion 31 </ b> B of the lens barrel 31 in the portion where the plane mirror 12 is attached.

  Of the reflecting mirrors 14, the curved mirror 13 is disposed above the flat mirror 12, and is fixed in the housing 30 so that the reflecting surface faces the flat mirror 12. In the present embodiment, the curved mirror 13 is disposed so that the entirety thereof is positioned above the lens barrel 31.

  FIG. 4 shows an example of the reflection angle changing mechanism 32. The reflection angle changing mechanism 32 includes an adjustment screw 41 provided on one side of the plane mirror 12, a coil-shaped adjustment spring 42 provided between the plane mirror 12 and the housing 30, and the plane mirror 12. 12 and a pressing spring 43 for fixing the other side edge portion. The adjustment screw 41 is screwed into a screw hole 12 </ b> A provided on one side of the flat mirror 12, and the lower end of the adjustment screw 41 is rotatably supported on the inner surface of the housing 30. The adjustment spring 42 is in contact with the bottom surface of the flat mirror 12 at the upper end and the inner surface of the housing 30 at the lower end, and always biases the flat mirror 12 upward. In this embodiment, one adjustment screw 41 and one adjustment spring 42 are provided, and two holding springs 43 are provided.

  When the adjustment screw 41 is rotated around the screw hole 12 </ b> A of the flat mirror 12 in the direction of the arrow A <b> 1, the flat mirror 12 resists the urging force of the adjustment spring 42 and the other side edge portion fixed by the holding spring 43. Is rotated in the direction of arrow B1. Conversely, when the adjustment screw 41 is rotated around the screw hole 12A of the plane mirror 12 in the direction of arrow A2, the plane mirror 12 is rotated in the direction of arrow B2 around the other side edge by the biasing force of the adjustment spring 42. To do. Thereby, the reflection angle (tilt) of the plane mirror 12 can be adjusted to an arbitrary angle.

  In FIG. 4, the Z direction indicates a direction parallel to the lens optical axis L (see FIG. 1), and the housing 30 shown in FIG. 3 is disposed along the Z direction. The X direction is a direction perpendicular to the lens optical axis L and is a direction along the width direction of the housing 30. Further, the Y direction is a direction perpendicular to the lens optical axis L, and indicates the vertical direction of the housing 30.

  FIG. 5 illustrates that the position of the projected image is adjusted by changing the angle of the plane mirror 12. In FIG. 5, the dotted line indicates the light ray Rb before the angle change, and the solid line indicates the light ray Ra after the angle change. Of the rays Rb before the angle change, the lowermost ray is Rb1, the uppermost ray is Rb2, and among the rays Ra after the angle change, the lowermost ray is Ra1, and the uppermost ray is Ra2. . As shown in the figure, when the angle of the plane mirror 12 is changed, the lowermost ray moves from Rb1 to Ra1 and the uppermost ray moves from Rb2 to Ra2, but the amount of movement is different on the screen 21. . That is, the movement amount (Ra1-Rb1) of the light beam is m1 at the bottom, the movement amount (Ra2-Rb2) of the light beam is m2 at the top, and the movement amount m2 at the top is more than the movement amount m1 at the bottom. Is also big. Therefore, the projected image on the screen 21 is distorted particularly near the top. In this embodiment, such distortion of the projected image is corrected electrically (in software).

  In the present embodiment, an image position adjustment lever 71 for changing the angle of the plane mirror 12 and a lever movement amount sensor 24 for detecting the movement amount of the image position adjustment lever 71 are provided. The lever movement amount sensor 24 constitutes a reflection angle change amount detection means. In addition, a control unit 25 is provided, and this control unit 25 takes in a detection signal from the lever movement amount sensor 24 and controls an image signal (an image signal input to the image display element 15), so that it is displayed on the screen 21. Electrically correct the distortion of the projected image.

  FIG. 6 illustrates that the distortion of the projected image is electrically corrected when the angle of the plane mirror 12 is changed (adjusted). In the figure, a solid line, a dotted line, and a broken line indicate projected images on the screen 21, respectively. In the drawing, for each of the solid line, the dotted line, and the broken line, the upper part indicates the uppermost light beam and the lower part indicates the lowermost light beam.

  In FIG. 6, the solid line is a projected image when the angle of the plane mirror 12 is not changed (adjusted), and the dotted line is a projected image when the angle of the plane mirror 12 is changed (adjusted). By adjusting (changing) the angle of the plane mirror 12, particularly the uppermost light beam is greatly moved and distorted as shown by a dotted line.

  In the present embodiment, by electrically correcting the projected image, as shown by the broken line, the entire light beam including the uppermost part of the light beam is prevented from being greatly distorted. The distortion correction amount of the projected image with respect to the tilt angle of the plane mirror 12 is stored in advance in a memory in the control unit 25 (see FIG. 5). When the inclination angle of the plane mirror is detected by the lever movement amount sensor 24 (see FIG. 5), the control unit 25 compares the detection signal fetched from the lever movement amount sensor 24 with the distortion correction amount accumulated in the memory. Then, the control unit 25 performs electrical control on the image signal input to the image display element 15 so that the projected image on the screen 21 is not distorted.

  The angle of the plane mirror 12 is changed manually. FIG. 7 shows an image projection apparatus (projector) that manually changes the angle of the plane mirror 12. As shown in FIG. 7, the image projection apparatus 20 according to the present embodiment is provided with an image position adjustment lever 71 on its side surface, and is configured to manually operate the image position adjustment lever 71. The image position adjusting lever 71 is connected to an adjusting screw (see FIG. 4) through a link mechanism and a gear mechanism, although not shown in the drawing.

  Then, when the image position adjusting lever 71 is moved in the arrow C1 direction, as shown in FIG. 4, the adjusting screw 41 is rotated in the arrow A2 direction, and the flat mirror 12 is rotated in the arrow B2 direction. As a result, as shown in FIG. 7, the entire projected image (shown by a solid line) on the screen 21 moves upward as shown by an arrow.

  Conversely, when the image position adjusting lever 71 is moved in the direction of arrow C2, as shown in FIG. 4, the adjustment screw 41 is rotated in the direction of arrow A1, and the plane mirror 12 is rotated in the direction of arrow B1. As a result, as shown in FIG. 7, the entire projected image (shown by dotted lines) on the screen 21 moves downward in the direction opposite to the arrow.

  FIG. 8 is a block diagram of an image projection apparatus configured to automatically correct distortion of a projected image when the angle of the plane mirror 12 is changed. An image signal is always input to the distortion correction circuit 81. When the mirror moving mechanism (image position adjusting lever 71 in FIG. 7) 82 is operated, the operation amount (the amount of movement of the image position adjusting lever 71 in the direction of arrow C1 or arrow C2 in FIG. 7) is changed to the mirror. It is detected by a sensor in the moving mechanism 82 (the lever movement amount sensor 24 in FIG. 5). Then, the mirror movement mechanism 82 outputs the operation amount of the image position adjustment lever 71 as a mirror movement amount to the distortion correction circuit 81, and the distortion correction circuit 81 inputs a signal of the mirror movement amount. The distortion correction circuit 81 is provided in the control unit 25 of FIG.

  In the distortion correction circuit 81, distortion of the image signal projected on the screen 21 is electrically corrected based on the mirror movement amount signal from the mirror moving mechanism 82, and the corrected image signal is used as the image display element. 15 and displayed on the image display element 15. The corrected image displayed on the image display element 15 is enlarged and projected on the screen 21 via the projection optical system 10.

  Note that the distortion correction amount of the projected image is stored in the memory in advance in the distortion correction circuit 81 so as to correspond to the mirror movement amount. When the mirror movement amount is input from the mirror moving mechanism 82, the distortion correction circuit 81 compares the input data with the data in the memory, and is configured to perform optimal distortion correction for the projected image. .

  FIG. 9 is a block diagram of an image projection apparatus configured to manually input a distortion image correction amount when the angle of the plane mirror 12 is changed. An image signal is always input to the distortion correction circuit 81. Then, the mirror moving mechanism (image position adjusting lever 71 in FIG. 7) 82 is operated and the amount of operation (in FIG. 7, the amount of movement of the image position adjusting lever 71 in the direction of arrow C1 or arrow C2) is determined. Then, the distortion correction amount of the projected image is manually input from the operation unit 83. The operation unit 83 outputs a distortion correction amount to the distortion correction circuit 81, and the distortion correction circuit 81 inputs a signal of the distortion correction amount. Note that when inputting the distortion correction amount of the projected image to the operation unit 83, an input operation may be performed via a remote controller.

  In the distortion correction circuit 81, distortion of the image signal projected on the screen 21 is electrically corrected based on the distortion correction amount signal from the operation unit 83, and the corrected image signal is converted into the image display element 15. To be displayed on the image display element 15. The corrected image displayed on the image display element 15 is enlarged and projected on the screen 21 via the projection optical system 10.

  According to the present embodiment, the distortion correction circuit 81 electrically corrects the distortion of the image projected on the screen 21 when the reflection angle of the plane mirror 12 is changed, thereby performing short projection image projection. In the apparatus, the projection height can be easily adjusted with a simple configuration.

  In particular, when the angle of the plane mirror 12 is changed, the optical path length from the plane mirror 12 to the screen 21 changes depending on the image position, and the projected image is distorted. According to the present embodiment, the position of the projection image can be adjusted even in a short projection image projection apparatus by electrically correcting the distortion of the projection image.

  In addition, according to the present embodiment, the angle of the plane mirror 12 instead of the curved mirror 13 is changed. Therefore, when the plane mirror 12 rotates and the reflection angle changes, the deterioration of the optical characteristics is suppressed. be able to.

  When detecting the amount of movement of the image position adjustment lever 71, a light amount sensor that detects reflected light at a predetermined position of the curved mirror 13 and transmitted light at a predetermined position of the dust-proof glass 22 instead of the lever movement amount sensor 24. May be provided. A camera that directly detects the image position on the screen 21 may be provided.

  In this embodiment, only the plane mirror 12 is tilted. However, both the plane mirror 12 and the curved mirror 13 may be tilted simultaneously. If comprised in this way, compared with the angle adjustment system of the plane mirror 12 of 1 sheet, degradation of a projection image can be suppressed further.

Example 2
FIG. 10 shows a second embodiment. In this embodiment, when the angle of the plane mirror 12 is changed by the reflection angle changing mechanism 32, the focus mechanism (for example, the lens 31C) of the lens group 11 is also moved along the lens optical axis L at the same time. Changing the position of the projected image on the screen 21 may change the optical path length and cause a focus shift.

  Therefore, in this embodiment, the image position adjusting lever 71 is connected to the lens 31C, and when the image position adjusting lever 71 is operated, the operating force is also transmitted to the lens 31C and interlocked with the angle change of the plane mirror 12. The lens 31C is moved on the lens optical axis L.

  According to the present embodiment, by performing the focus adjustment that moves the lens 31C on the lens optical axis L, the focus does not change even if the position of the projection image on the screen 21 is changed, and a high-quality projection image can be obtained. Can do.

Example 3
FIG. 11 shows a third embodiment. In the present embodiment, a single curved mirror 91 is provided as the reflecting mirror 14. The curved mirror 91 can be tilted in the directions D1 and D2.

  The reflection angle changing mechanism for inclining the curved mirror 91 in the directions D1 and D2 is the same as in the first embodiment. For example, when the curved mirror 91 is tilted in the direction of arrow D1, the imaging light beam R passes through the position indicated by the solid line, and when the curved mirror 91 is tilted in the direction of arrow D2, the imaging light beam R passes through the position indicated by the broken line. Thereby, the position of the projected image on the screen 21 can be moved.

  According to the present embodiment, since only one curved mirror 91 is provided as the reflection mirror 14, the configuration of the entire image projection apparatus can be made compact.

  A flat mirror may be provided instead of the curved mirror 91.

Example 4
In Examples 1 to 3, the illumination optical system that projects illumination light onto the image display element 15 has not been described. In this embodiment, an image projection apparatus equipped with an illumination optical system will be described. Usually, an illumination optical system is mounted so that high illumination efficiency can be obtained.

  As shown in FIG. 11, the image projection apparatus according to this embodiment is provided with an illumination optical system 100 for irradiating the image display element 15 with illumination light. Between the illumination optical system 100 and the projection optical system 10, a polarization separation means 101 is provided.

  The illumination optical system 100 includes an illuminance uniformizing means 106 called an integrator optical system that uniformizes the illuminance of a light beam having a directivity reflected by the light source 102, the reflector 103 in the vicinity of the light source 102, the relay lenses 104 and 105, and the reflector 103. Etc. Then, illumination light is irradiated from the illumination optical system 100 to the image display element 15, and a uniform illumination distribution is obtained on the image display element 15.

  As the light source 102, a halogen lamp, a xenon lamp, a metal halide lamp, an ultrahigh pressure mercury lamp, an LED, or the like is used. The reflector 103 may be integrated with the light source 102.

  A color wheel 107 is provided between the relay lens 105 and the polarization separating means 101. The color wheel 107 colors the illumination light. By controlling the image of the image display element 15 in synchronization with the color wheel 107, a color image can be projected on the screen 21. Reference numeral 108 denotes a polarization conversion element.

  When a reflection type liquid crystal image display element is used as the image display element 15, more efficient illumination is possible by using the polarization separation means 101 that separates the illumination optical path and the projection optical path. When a DMD panel is used as the image display element 15, optical path separation using a total reflection prism or the like is employed. Thus, an appropriate optical system is employed according to the type of the image display element 15.

  FIG. 13 shows an example in which illumination light transmitted through a plurality of color filters such as red, green, and blue is applied and the light synthesized by the color synthesis unit 110 is incident on the projection optical system 10. In FIG. 13, reference numerals 111 and 112 denote color separation means. Also, polarization separation means 113, 114, 115 are provided corresponding to the image display elements 15A, 15B, 15C, respectively, and these polarization separation means 113, 114, 115 are connected to the color composition means 110. The illumination light synthesized by the color synthesis unit 110 is projected on the screen 21 via the projection optical system 10. Reference numeral 116 denotes a mirror.

  By mounting the illumination optical system 100 in the present embodiment, it is possible to obtain highly efficient illumination efficiency.

  Although the embodiments of the present invention have been described in detail with reference to the drawings, each of the above embodiments is only an example of the present invention, and the present invention is not limited only to the configuration of each of the above embodiments. . Needless to say, changes in design and the like within the scope of the present invention are included in the present invention.

  For example, the case where the reflecting mirror 14 is composed of the flat mirror 12 and the curved mirror 13 (Example 1) and the case where the reflecting mirror 14 is composed of the curved mirror 91 (Example 3) is mentioned, but the number of mirrors is one or two. Not limited, there may be three or more. In this case, the inclination angle of one or a plurality of mirrors is adjusted.

DESCRIPTION OF SYMBOLS 10 Projection optical system 11 Lens group 12 Plane mirror 13 Curved surface mirror 14 Reflection mirror 15 Image display element (light modulation means)
20 Image projection device 21 Screen 22 Dust-proof glass 24 Lever movement amount sensor (reflection angle change amount detection means)
25 Control unit (image distortion correction means)
DESCRIPTION OF SYMBOLS 30 Housing 31 Lens barrel 32 Reflection angle change mechanism 41 Adjustment screw 42 Adjustment spring 43 Holding spring 71 Image position adjustment lever 81 Distortion correction circuit 82 Mirror moving mechanism 83 Operation part 91 Curved surface mirror 100 Illumination optical system L Lens optical axis (optical axis) )
R Imaging beam

JP 2011-242606 A JP 2011-253023 A JP-A-10-111533

Claims (8)

A light modulating unit that receives light from the light source and emits an optical image modulated based on the image signal;
A projection optical system for enlarging and projecting an optical image emitted from the light modulation means on a screen,
The projection optical system is an image projection device including a lens group and a reflection mirror disposed behind the lens group along an optical axis,
A reflection angle changing mechanism for changing the reflection angle of the reflection mirror to adjust the position of the image projected on the screen;
Image distortion correction means for controlling the image signal to electrically correct the distortion of the projected image on the screen when the reflection angle of the reflection mirror is changed by the reflection angle changing mechanism. An image projection device characterized by the above. Reflection angle change amount detection means for detecting the change amount of the reflection angle in the reflection angle change mechanism is provided,
The image projection according to claim 1, wherein the image distortion correction unit includes a distortion correction circuit that electrically corrects distortion of the projection image based on a detection result of the reflection angle change amount detection unit. apparatus.   When the reflection angle of the reflection mirror is changed by the reflection angle changing mechanism, the image distortion correction unit moves the lens group according to the change amount and focuses the image projected on the screen. The image projection apparatus according to claim 1, wherein the image projection apparatus is performed. The reflecting mirror includes a plane mirror;
The image projection apparatus according to claim 1, wherein the reflection angle changing mechanism is connected to the plane mirror.   The image projection apparatus according to claim 4, wherein the reflection mirror includes a curved mirror in addition to the plane mirror. The reflection mirror includes a curved mirror,
The image projection apparatus according to claim 1, wherein the reflection angle changing mechanism is connected to the curved mirror.   The image projection apparatus according to claim 6, wherein the reflection mirror includes a plane mirror in addition to the curved mirror. The reflection mirror includes a plane mirror and a curved mirror,
The image projection apparatus according to claim 1, wherein the reflection angle changing mechanism is connected to the flat mirror and the curved mirror.