JP2008009136A - Image projection device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image projection device readily installed on a table in conference or the like and projecting an image in front of all the persons present, thereby progressing argument while looking at each other. <P>SOLUTION: The image projection device for projecting an image projects a plurality of images in a plurality of directions around an image projection device main body nearly on the same surface as the installation surface of the image projection device. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an image projection apparatus used in a meeting in an office.

<Conventional example 1>
2. Description of the Related Art Conventionally, a projection display device (image projection device) is known which forms an image using a light modulation device such as a liquid crystal light valve, and uses the projection optical system to form the image on a screen, a wall surface or the like. An example of the projection display device will be described with reference to FIGS. FIG. 19 is an external perspective view of the projection display device, and FIG. 20 is a diagram showing the internal structure of the device shown in FIG.

  20, 110 is a light source unit, 111 is a lamp, 112 is a reflector, 113a and 113b are fly-eye lenses, 114 is a superposition lens, 115 is a PBS prism, 116a, 116b and 116c are spatial light modulators, and 117 is a cross dichroic. A prism 118 is a projection optical system.

  The light source 110 includes a lamp 111 such as a metal halide, and a reflector 112 that reflects light diverging radially from the lamp 111 into parallel light. The parallel light reflected by the reflector 112 is applied to the fly-eye lenses 113a and 113b. A superimposing lens 114 is disposed in the vicinity of the exit of the fly-eye lenses 113a and 113b. Here, the parallel light before entering the fly-eye lenses 113a and 113b has an intensity distribution such that the light intensity at the center is high and the light intensity at the outer periphery is low. The collimated light having this intensity distribution passes through the fly-eye lenses 113a and 113b, so that the luminous flux is once divided, and is superposed by the superimposing lens 114 disposed in the vicinity of the exit port, thereby producing a luminous flux with a uniform light intensity distribution. Obtainable.

  A light beam having a uniform intensity is bent by the PBS prism 115, then enters the cross dichroic prism 117, is separated for each color, and each color is reflected by a reflective spatial light modulator 116a, 116b, 116c provided for each color. An image is formed every time. Further, these three color images are synthesized by the cross dichroic prism 117, and then transmitted through the PBS prism to form an image on a screen or the like through the projection optical system 118.

  There is also an example in which the metal halide lamp 111 is replaced with light emitting diodes of three colors of red, blue, and green. By using a light emitting diode as a light source to light each color in time series, the single spatial light modulation device described above is sufficient, so that the device can be miniaturized and cost and power consumption can be reduced. Some spatial light modulators use a micromirror array in addition to liquid crystal.

  However, the image projection apparatus as described above is suitable when one person makes a presentation to a large number of people, but is not suitable when several persons discuss each other while facing each other on the same table. There is also a problem that there is no place to project.

<Conventional example 2>
Another conventional example disclosed in Patent Document 1 will be described. As shown in FIG. 1 of Patent Document 1, this image projection apparatus projects a panoramic image onto a cylindrical screen by projecting an image around 360 degrees around the image projection apparatus body. It is something that can be done.

  However, devices that project an image in the shape of a cylinder or dome around it have been conceived so far, but since the image is in all directions to the observer, it will be discussed at the same desk at a conference or the like Not suitable for the place. Also, since a dedicated screen is required, it cannot be easily installed in an office meeting room.

<Conventional example 3>
An image projection apparatus intended for use in a meeting or the like in an office is disclosed in Patent Document 2. As shown in FIG. 1 of Patent Document 2, an image projector is installed on the ceiling of the conference room, and a plurality of images are displayed in front of all the participants surrounding the table.

However, even in this conventional example, it is inconvenient that the image projection apparatus must be installed on the ceiling and cannot be easily moved to another place.
JP 2005-091449 A JP 2005-318268 A

  It is an object of the present invention to provide an image projection apparatus that can be easily placed on a table at a meeting, etc., and project an image in front of all attendees so that discussions can proceed while looking at each other's faces. And

  In order to achieve such an object, the invention described in claim 1 is an image projection apparatus for projecting an image, and is provided on a surface substantially the same as the installation surface of the image projection apparatus and around the image projection apparatus main body. A plurality of images are projected in the direction.

  According to a second aspect of the present invention, in the first aspect of the invention, the light source unit includes a plurality of light source units, a plurality of spatial light modulation devices that form a plurality of images, and a plurality of projection optical systems. .

  According to a third aspect of the present invention, in the first aspect of the present invention, a plurality of light source units, a branching unit for branching light from the light source unit and leading to a plurality of spatial light modulators, and a plurality of different images are formed. A spatial light modulator and a plurality of projection optical systems.

  According to a fourth aspect of the present invention, in the first aspect of the present invention, the one light source unit, the one spatial light modulator that forms an image, and the image branch that branches the image formed by the spatial light modulator into a plurality of parts. And a plurality of projection lenses.

  The invention according to claim 5 is the invention according to any one of claims 1 to 4, wherein the plurality of images projected in a plurality of directions are seamlessly connected to adjacent images. To do.

  According to a sixth aspect of the present invention, in the first aspect of the present invention, the laser light source, collimating means for collimating the divergent light from the laser light source, and scanning means for scanning the laser light that has become the parallel light in a line shape. And an inclined rotating mirror that is inclined with respect to an axis perpendicular to the installation surface and that rotates about an axis perpendicular to the installation surface, and tilts and rotates the laser beam scanned in a line by the scanning means By reflecting with a mirror, a two-dimensional image is projected on the periphery of the main body of the image projection apparatus and on substantially the same surface as the installation surface of the image projection apparatus.

  According to a seventh aspect of the invention, in the invention according to any one of the first to sixth aspects, the output of the light source is stopped when detecting the overturn of the image projection device and the detecting means for detecting the overturn of the image projection device. And stopping means.

  The invention according to claim 8 is the invention according to any one of claims 1 to 7, further comprising projection number changing means for changing the number of images.

  The invention according to claim 9 is the invention according to any one of claims 1 to 8, further comprising a projection position adjusting means for adjusting the position of the image.

  A tenth aspect of the present invention is the method according to any one of the first to ninth aspects, further comprising a detection unit that detects the number or position of persons around the image projection apparatus, and the detection unit detects the number of persons detected by the detection unit. An image is projected according to the number or position.

  The invention according to claim 11 is the invention according to any one of claims 1 to 10, wherein the image is corrected to a substantially rectangular shape on the projection plane.

  According to the present invention, an image projection apparatus capable of projecting a plurality of images around the image projection apparatus main body and on the same plane as the installation surface is realized. By using this image projection device at the center of the conference table, it is easy to set up, allowing discussions to be carried out while looking at the faces of everyone around the table, activating the conference and promoting knowledge creation activities, etc. It becomes possible.

  The best mode for carrying out the present invention will be described below in detail with reference to the accompanying drawings.

A first embodiment of the present invention will be described with reference to FIGS.
As shown in FIG. 1, the image projection apparatus 10 according to the present embodiment includes four image projection units of image projection units 1, 2, 3, and 4. In FIG. 1, 12 is a projection image formed by each of the image projection units 1 to 4, and 11 is a projection surface on which the projection image 12 is formed.

  As shown in FIG. 2, each of the image projection units 1 to 4 includes a light source unit 110, fly-eye lenses 113a and 113b, a superimposing lens 114, a PBS prism 115, spatial light modulators 116r (red), 116g (green), and 116b. (Blue), a cross dichroic prism 117, and a projection optical system 118.

  The light source unit 110 includes a lamp (not shown, see FIG. 20) such as a metal halide, and a reflector 112 that reflects light emitted radially from the lamp into parallel light. The parallel light reflected by the reflector 112 enters the fly-eye lenses 113a and 113b. A superimposing lens 114 is disposed in the vicinity of the exit of the fly-eye lenses 113a and 113b. Here, the parallel light before entering the fly-eye lenses 113a and 113b has an intensity distribution such that the light intensity at the center is high and the light intensity at the outer periphery is low. The parallel light having this intensity distribution passes through the fly-eye lenses 113a and 113b, so that the light beam is once split and superimposed on the spatial light modulator by the superimposing lens 114 disposed in the vicinity of the exit port. A light beam having a uniform intensity distribution can be obtained.

  A light beam having a uniform intensity passes through the PBS prism 115 and is then separated into three colors of red, blue, and green by the cross dichroic prism 117, and spatial light modulators 116r, 116g, and 116b provided for the respective colors. An image is formed for each color. These three light beams are again combined by the cross dichroic prism 117, reflected by the PBS prism 115, and then the projection image 12 of FIG. 1 is formed on the projection surface through the projection optical system 118.

  As shown in FIG. 3, each of the image projection units 1 to 4 is projected toward four directions around the image projection device 10, and the installation surface 11 of the image projection device 10 is a projection surface on the surface. An image is projected. Thereby, a plurality of images (the same image or different images) can be projected on the periphery of the image projection apparatus main body and on the same surface as the installation surface. This image projection device can be easily set by placing it at the center of the table at a meeting, etc., and images can be projected to the front of all attendees (for example, on a desk), so the participants in the conference You can proceed with the discussion while looking at the face.

  As shown in FIG. 4, each of the image projection units 1 to 4 can turn off the image output independently, and the power consumption for driving the lamp and the spatial light modulation device according to the number of users can be reduced. Can save.

  FIG. 5 is an image diagram of a conference using the image projection apparatus of the present application. As shown in FIG. 5, the projected image is corrected to a rectangular shape on the projection plane. Therefore, an image without distortion on the projection surface can be obtained.

  Instead of a metal halide lamp or the like, a light emitting diode or laser can be used as the light source. In this case, by using three colors of blue, green, and red for the light emitting diode and the laser, it is not necessary to separate the colors, and it is compact and it is possible to suppress power consumption and heat generation.

A second embodiment in which the light source and the integration function for uniformizing the intensity distribution of the light beam emitted from the light source are shared with respect to the first embodiment will be described with reference to FIG.
In FIG. 6, the image projector 10 includes an LED light source unit 120, fly-eye lenses 113a and 113b, a superimposing lens 114, a PBS prism 115a (not shown), 115b, 115c (not shown), and 115d (not shown). , Spatial light modulators 116a, 116b, 116c (not shown), 116d (not shown), and projection optical systems 118a, 118b, 118c, 118d.

  The LED light source unit 120 includes blue, green, and red three-color LED light sources 121r, 121g, and 121b, and a collimator lens 122 that converts light radiated from these LED light sources into substantially parallel light. The parallel light emitted from the collimator lens 122 enters the fly-eye lenses 113a and 113b. A superimposing lens 114 is disposed in the vicinity of the exit of the fly-eye lenses 113a and 113b. Here, the parallel light before entering the fly-eye lenses 113a and 113b has an intensity distribution such that the light intensity at the center is high and the light intensity at the outer periphery is low. The parallel light having this intensity distribution passes through the fly-eye lenses 113a and 113b, so that the light beam is once divided and superimposed on the spatial light modulator by the superimposing lens 114 arranged in the vicinity of the exit port. A light beam having a uniform intensity distribution can be obtained.

  The luminous flux with uniform intensity is set to a size that covers the four PBS prisms 115a, 115b, 115c, and 115d. The light beams incident on the four PBS prisms 115a, 115b, 115c, and 115d are transmitted through the respective PBS prisms 115a, 115b, 115c, and 115d, and images are formed by the spatial light modulators 116a, 116b, 116c, and 116d. The color expression uses a field sequential method in which three colors are divided by time to form an image. The images formed by the respective spatial light modulators are reflected by the corresponding PBS and projected onto the projection plane through the corresponding projection optical systems 118a, 118b, 118c, and 118d. The present embodiment can be configured in a small size and at low cost by sharing the light source.

A third embodiment in which the spatial light modulation device is shared with the second embodiment will be described with reference to FIG.
In FIG. 7, an image projection apparatus 10 includes an LED light source unit 120, fly-eye lenses 113a and 113b, a superimposing lens 114, a PBS prism 115, a spatial light modulator 116, a projection optical system 118, an image branching unit (half mirror, flat mirror). ).

  The LED light source unit 120 includes blue, green, and red three-color LED light sources 121r, 121g, and 121b, and a collimating lens 122 that converts light radiated from these LED light sources into substantially parallel light. The parallel light emitted from the collimator lens 122 enters the fly-eye lenses 113a and 113b. A superimposing lens 114 is disposed in the vicinity of the exit of the fly-eye lenses 113a and 113b. Here, the parallel light before entering the fly-eye lenses 113a and 113b has an intensity distribution such that the light intensity at the center is high and the light intensity at the outer periphery is low. The parallel light having this intensity distribution passes through the fly-eye lenses 113a and 113b, so that the light beam is once divided and superimposed on the spatial light modulator by the superimposing lens 114 arranged in the vicinity of the exit port. A light beam having a uniform intensity distribution can be obtained. An image is formed by irradiating the spatial light modulator 116 with a light beam having a uniform intensity distribution. The color expression uses a field sequential method in which an image is formed by dividing three color LEDs by time. The formed image is separated into a plurality of directions after the spatial light modulator 116 by a half mirror and a flat mirror as an image branching unit, and projected onto a projection surface through a projection optical system 118 provided for each direction. Is done. The present embodiment can be configured in a small size and at low cost by sharing the light source. In addition, the cost can be reduced by sharing the spatial light modulation device.

  Example 4 will be described with reference to FIGS. FIG. 8 is an external view of the image projection apparatus of this embodiment. 49, the configuration of the image projection apparatus of this embodiment will be described. The image projection apparatus 1 includes a laser light source unit 140, a scanning mirror 142, and a rotating and tilting mirror 143.

  A detailed view of the laser light source unit 140 is shown in FIG. The laser light source unit 140 includes a red laser 140r, a green laser 140g, a blue laser 140b, and collimating lenses 141r, 141g, and 141b corresponding to the respective lasers, and composite mirrors 144a, 144b, and 144c, and laser beams emitted from the respective lasers. Becomes substantially parallel light by the collimating lens. The laser beams of the respective colors are synthesized by the synthesis mirrors 144a, 144b, and 144c and are irradiated on the uniaxial scanning mirror 142 (see FIG. 9). As the scanning mirror 142 rotates, the laser beam is scanned in a line shape and reflected by a rotating tilt mirror 143 disposed obliquely with respect to the central axis of the image projection apparatus main body. A two-dimensional image is obtained around the main body by reflecting the laser beam with the rotating and tilting mirror 143.

  As shown in the right part of FIG. 9, the image may be corrected to a substantially rectangular shape on the projection plane. Thereby, an image without distortion on the projection surface can be obtained.

  Synthetic mirrors 144a, 144b, and 144c are, for example, a mirror 141a that reflects all light 140r, and 144b that efficiently transmits 140r light and reflects 140g light efficiently. 144c can be configured by a mirror that efficiently reflects the light of 140r and 140g and efficiently transmits the light of 140b. 144b and 144c are so-called dichroic mirrors.

  FIG. 11 is an exploded perspective view of an example of a scanning mirror. In recent years, research on deflection devices using silicon micromachining has been promoted, and as disclosed in Japanese Patent No. 2924200 and No. 30111144, an oscillating mirror and a torsion beam that pivotally supports it are integrally formed on a Si substrate. A scheme has been proposed. According to this method, there is an advantage that the mirror surface size can be reduced and the size can be reduced, and since reciprocal vibration is performed using resonance, high speed operation is possible but low noise and low power consumption are possible.

  The vibrating mirror 460 forms a movable mirror by cutting out the Si substrate by etching. In the embodiment, the torsion beam 442 and the planar coil 463 are formed from one side of the Si substrate by a dry process by plasma etching, and the vibration plate 443 to be a vibration mirror and the other part except the frame 446 are passed through to form the vibration mirror. Form a structure. Here, the width of the torsion beam 442 is about 40 to 60 μm.

  Furthermore, in the structure of the vibrating mirror, a reflective surface is formed by a metal thin film such as an aluminum thin film or a gold thin film or a dielectric multilayer film on the part to be a mirror, and patterning of a metal thin film or the like on one or both surfaces in the movable part Thus, a terminal wired through the coil pattern 463 and the torsion beam is formed.

  On the mounting substrate 448, a frame-shaped pedestal 466 for mounting the vibration mirror 460 and a yoke 449 formed so as to surround the vibration mirror are provided. A pair of permanent magnets 450 that join the N poles and generate a magnetic field in a direction perpendicular to the rotation axis are joined.

The vibrating mirror 460 is mounted on the pedestal 466 with the movable mirror face up, and a Lorentz force is generated on each side parallel to the rotation axis of the coil pattern 463 by passing an electric current between the terminals, and the torsion beam 442 is twisted. A rotational torque T that rotates the vibration plate 443 serving as a movable mirror is generated, and when the current is turned off, it returns to the horizontal due to the return force of the torsion beam. Therefore, the diaphragm 443 can be reciprocally oscillated by alternately switching the direction of the current flowing through the coil pattern 463.
Then, when the current switching period is brought close to the natural frequency of the primary vibration mode of the structure constituting the movable mirror with the torsion beam as the rotation axis, the so-called resonance frequency f0, the amplitude is excited and a large deflection angle is obtained. Obtainable. Therefore, in general, the scanning frequency fd is set in accordance with the resonance frequency f0.

  FIG. 12 is a block diagram of a drive circuit that amplifies the vibration mirror. As described above, the planar coil formed on the back side of the oscillating mirror is applied with an AC voltage or a pulse wave voltage so that the direction of current flow is switched alternately, so that the deflection angle θ is constant. Adjust the gain of the current to flow through and reciprocate.

  Conventionally, the fd scanning frequency is generally controlled so as to follow the change in the resonance frequency f0 due to environmental changes such as temperature. However, if the scanning frequency fd changes, the scanning line pitch shifts. Therefore, in the embodiment, the scanning frequency fd is fixed to a single frequency that is excluded from the resonance frequency f0, and the deflection angle θ can be increased or decreased according to gain adjustment.

  Over time, the deflection angle θ is detected based on the scanning time between the sensor, the synchronization detection sensor 604 and the termination detection sensor 605, which is a beam scanned by the movable mirror at the start and end of the scanning region. It is also possible to control the angle θ to be constant.

FIG. 13 shows the configuration of the rotating tilt mirror shown in FIG.
When it is desired to change the number of projected images depending on the number of persons, as shown in FIG. 14, by controlling the driving cycle of the single-axis scanning mirror 142 and the laser emission cycle with respect to the rotation number of the rotating and tilting mirror 143. The display number of images per rotation is changed. In FIG. 14, a person detection sensor 145 is provided, and the number of persons around the installed table is detected to automatically determine the display number. In this way, by detecting a person around the apparatus, a necessary number of images can be automatically projected.

  Further, no matter where the person is around the table, the driving cycle of the single-axis scanning mirror 142 and the laser emission cycle are controlled with respect to the rotational speed of the rotating tilt mirror 143 according to the same principle as described above. As shown in FIG. 15, the projection position of the screen can be changed. Thus, by detecting a person around the apparatus, an image can be automatically projected at a required position.

  In FIG. 15, a person detection sensor 145 is provided, and the display position is automatically changed by detecting the position of a person around the installed table. As a human detection method used for the human detection sensor, it can be detected by a method of detecting body temperature using infrared rays or a method based on image recognition. Even if the detection sensor does not detect a person, an IC tag or the like may be detected and projected to the place.

  Further, as shown in FIG. 16, by providing a tilt mirror 146 after the rotating tilt mirror, not only the rotating direction of the rotating tilt mirror 143 but also the projection position in the rotating radius direction can be changed.

  Also, as shown in FIG. 17, it is possible to share a large, high-resolution screen with a large number of people by displaying the entire circumference and projecting a seamless image. Thereby, a large screen and a high-resolution image can be obtained by connecting an adjacent screen and an image.

  Further, by equipping an inertial sensor as a detecting means for detecting a fall, a shutter installed in the laser emission unit, and a laser emission safety system as shown in FIG. Even when the laser beam is fallen or falls down due to an earthquake or the like, the laser beam is immediately shut off and the power is turned off, so that it is possible to prevent accidents such as direct visual observation of the laser beam. In the system of FIG. 18, the control unit constantly monitors the output of the inertial sensor, and when detecting an acceleration exceeding a set threshold, the shutter configured by an electromagnetic shutter mechanism is closed and the laser power is turned off. Yes. Thereby, when the image projection apparatus falls down, it is possible to eliminate the risk that the laser is projected toward the human body.

  As mentioned above, although each Example of this invention was described, it is not limited to said each Example, A various deformation | transformation is possible in the range which does not deviate from the summary.

  The present invention can be applied to all image projection apparatuses that project an image on a predetermined surface.

1 is a perspective view illustrating a configuration of an image projection apparatus according to Embodiment 1 of the present invention. It is a perspective view which shows the structure of the image projection unit which concerns on Example 1 of this invention. It is a perspective view which shows an example at the time of the image projection of the image projector which concerns on Example 1 of this invention. It is a perspective view which shows an example at the time of the image projection of the image projector which concerns on Example 1 of this invention. It is a figure which shows the time of image projection of the image projector which concerns on Example 1 of this invention. It is a perspective view which shows the structure of the image projector which concerns on Example 2 of this invention. It is a figure which shows the structure of the image projector which concerns on Example 3 of this invention. It is a perspective view which shows an example at the time of the image projection of the image projector which concerns on Example 4 of this invention. It is a figure which shows the structure of the image projector which concerns on Example 4 of this invention. It is a figure which shows the structure of the laser light source unit of the image projector which concerns on Example 4 of this invention. It is a perspective view which shows the structure of the scanning mirror of the image projector which concerns on Example 4 of this invention. It is a block diagram which shows the structure of the drive circuit of the image projector which concerns on Example 4 of this invention. It is a perspective view which shows the structure of the rotation inclination mirror of the image projector which concerns on Example 4 of this invention. It is a perspective view which shows an example at the time of providing the person detection sensor in the image projector which concerns on Example 4 of this invention. It is a perspective view which shows an example at the time of providing the person detection sensor in the image projector which concerns on Example 4 of this invention. It is a figure which shows an example at the time of providing the tilting mirror in the image projector which concerns on Example 4 of this invention. It is a figure which shows the time of image projection of the image projector which concerns on Example 4 of this invention. It is a block diagram which shows an example at the time of providing the fall detection means to the image projector which concerns on Example 4 of this invention. It is a perspective view which shows the external appearance of the image projector of a prior art. It is a figure which shows the structure of the image projector of a prior art.

Explanation of symbols

1, 2, 3, 4 Image projection unit 10 Image projection device 11 Image projection surface (image projection device installation surface)
12 projection image 110 light source unit 111 lamp 112 reflector 113a, 113b fly eye lens 114 superimposing lens 115, 115b PBS prism 116a, 116b, 116c, 116r, 116g, 116b spatial light modulator 117 cross dichroic prism 118, 118a, 118b, 118c 118d Projection optical system 120 LED light source unit 121r, 121g, 121b LED light source 122 Collimating lens 140 Laser light source unit 140r, 140b, 140g Laser 141r, 141b, 141g Collimating lens 142 Scanning mirror 143 Rotating tilt mirror 144a, 144b, 144c Composite mirror 145 Human detection sensor 146 tilt mirror 442 torsion beam 443 diaphragm 44 6 Frame 448 Mounting board 449 Yoke 450 Permanent magnet 460 Vibrating mirror 463 Coil pattern 466 Base 601 Drive pulse generator / PLL circuit 602 Gain adjuster 603 Movable mirror driver 604 Synchronization detection sensor 605 End detection sensor 606 Drive light source 607 Image formation Control unit 608 Pixel clock generation unit 609 Amplitude calculation unit

Claims (11)

An image projection apparatus for projecting an image,
An image projection apparatus that projects a plurality of images on a plane substantially the same as an installation plane of the image projection apparatus and in a plurality of directions around the image projection apparatus main body. A plurality of light source units;
A plurality of spatial light modulators for forming the plurality of images;
A plurality of projection optical systems;
The image projection apparatus according to claim 1, further comprising: One light source unit,
Branching means for branching light from the light source unit and leading to a plurality of spatial light modulators;
A plurality of spatial light modulators for forming different images,
A plurality of projection optical systems;
The image projection apparatus according to claim 1, further comprising: One light source unit,
A spatial light modulator for forming an image;
Image branching means for branching an image formed by the spatial light modulator into a plurality of parts;
A plurality of projection lenses;
The image projection apparatus according to claim 1, further comprising:   5. The image projection apparatus according to claim 1, wherein the plurality of images projected in the plurality of directions are seamlessly connected to adjacent images. 6. A laser light source;
Collimating means for collimating divergent light from the laser light source;
Scanning means for scanning the parallel laser beam in a line;
An inclined rotating mirror that is inclined with respect to an axis perpendicular to the installation surface and rotates about an axis perpendicular to the installation surface;
The laser beam scanned in a line by the scanning unit is reflected by the inclined rotating mirror, so that a two-dimensional image is formed around the image projection apparatus main body and substantially the same plane as the installation plane of the image projection apparatus. The image projection apparatus according to claim 1, wherein the image projection apparatus projects the image onto the screen. Detecting means for detecting a fall of the image projection device;
Stop means for stopping the output of the light source when the fall of the image projection device is detected;
The image projection apparatus according to claim 1, comprising:   The image projection apparatus according to claim 1, further comprising a projection number changing unit that changes the number of the images.   The image projection apparatus according to claim 1, further comprising a projection position adjustment unit that adjusts a position of the image. Detecting means for detecting the number or position of persons around the image projector;
The image projection apparatus according to claim 1, wherein the image is projected in accordance with the number or position of persons detected by the detection unit.   The image projection apparatus according to claim 1, wherein the image is corrected to a substantially rectangular shape on a projection surface.

Images