JP7653181B2 - Mobile projection device and program for mobile projection device - Google Patents

Description

This invention relates to a mobile projection device and a program for a mobile projection device.

For example, Patent Document 1 (JP Patent Publication No. 2007-229855) proposes an autonomous mobile robot that moves in accompaniment to a specific person and can project and display image information related to the area around the moving point onto an appropriate projection surface. According to the invention of Patent Document 1, image information such as advertisements and warnings related to the current location of a moving person can be displayed.

JP 2007-229855 A

However, the autonomous mobile robot of the invention of Patent Document 1 must accompany a specific person when moving. In reality, all a user needs is for a projection image to be projected when and where they need it, so having an autonomous mobile robot accompany the user is itself cumbersome, and the user must also consider the path of travel for the autonomous mobile robot to accompany the user, which is troublesome.

The autonomous mobile robot of the invention in Patent Document 1 uses the head or back of a specific person or the road surface as the projection surface. For this reason, when there are multiple viewers, it becomes difficult for all of them to view the projection image at the same time. In particular, when there are many viewers, there is a risk that people at the back, for example, will be unable to view the projection image because the people in front get in the way.

The aim of this invention is to provide a mobile projection device that can solve the above problems.

In order to solve the above problems, the present invention provides:
an aerial flight mechanism for flying in the air;
a projector unit for projecting an image;
a speaker that outputs a sound related to the image;
a camera for photographing a viewer viewing the projected image;
a number-of-viewers detection unit that detects the number of viewers from the captured image of the camera;
a control unit that controls a volume of the sound emitted from the speaker in accordance with the number of viewers detected by the number-of-viewers detection unit;
A communication means for receiving call information;
Equipped with
Based on information for specifying a location included in the call information, the projector moves to a location near a viewer who is in a place where the call information is transmitted, and projects the image by the projector unit.
The present invention provides a mobile projection device characterized by the above.

The mobile projection device of this invention is equipped with an aerial flight mechanism and can fly through the air. Therefore, it can fly to a desired location when needed and provide a projection image to viewers at that location using the projector unit it is equipped with.

The mobile projection device of this invention detects the number of viewers from the image captured by the camera, and controls the volume of the sound related to the image that is emitted from the speaker according to the detected number of viewers.

With the projection device of this invention, the volume of the sound related to the projected image that is emitted from the speaker is controlled according to the number of viewers, so viewers can hear the sound at an appropriate volume.

1 is a diagram for explaining a configuration example of a first embodiment of a mobile projection device according to the present invention; 1 is a block diagram for explaining an example of the configuration of a drive control device of a first embodiment of a mobile projection device according to the present invention; FIG. 2 is a diagram showing a part of a flowchart for explaining an example of a processing operation of the first embodiment of the mobile projection device according to the present invention. FIG. 2 is a diagram showing a part of a flowchart for explaining an example of a processing operation of the first embodiment of the mobile projection device according to the present invention. 1 is a diagram showing an example of a usage mode of a first embodiment of a mobile projection device according to the present invention; FIG. 11 is a diagram for explaining a configuration example of a second embodiment of a mobile projection device according to the present invention. 11A and 11B are diagrams illustrating an example of a usage mode of a mobile projection device according to a second embodiment of the present invention. FIG. 13 is a diagram for explaining a configuration example of a third embodiment of a mobile projection device according to the present invention. FIG. 13 is a diagram for explaining a configuration example of a third embodiment of a mobile projection device according to the present invention. 13A and 13B are diagrams illustrating an example of a usage mode of a mobile projection device according to a fourth embodiment of the present invention. FIG. 13 is a block diagram for explaining an example of the configuration of a drive control device of a mobile projection device according to a fourth embodiment of the present invention. FIG. 13 is a diagram showing a part of a flowchart for explaining an example of a processing operation of a mobile projection device according to a fourth embodiment of the present invention. FIG. 13 is a diagram showing a part of a flowchart for explaining an example of a processing operation of a mobile projection device according to a fourth embodiment of the present invention.

[First embodiment]
Fig. 1 is a diagram showing an example of the configuration of a first embodiment of a mobile projection device according to the present invention. The mobile projection device 1 according to the embodiment of the present invention is configured to be capable of autonomously flying and moving through the air. Fig. 1(A) is a diagram showing the mobile projection device 1 according to this embodiment as seen from above, and Fig. 1(B) is a diagram showing the mobile projection device 1 according to this embodiment as seen from the front.

The mobile projection device 1 of this embodiment comprises an aerial flight mechanism 2 having a so-called quadcopter structure, and a drive control unit 3. The aerial flight mechanism 2 is driven and controlled by the drive control unit 3. As shown in FIG. 1, the aerial flight mechanism 2 is configured by attaching rotor mechanisms 5A, 5B, 5C, and 5D to the tips of four arms 4A, 4B, 4C, and 4D extending from the drive control unit 3.

The rotor mechanisms 5A, 5B, 5C, and 5D are configured to rotate the rotors 52A, 52B, 52C, and 52D by rotating the rotor shafts (not shown) using the motor drives 51A, 51B, 51C, and 51D, respectively. The motor drives 51A, 51B, 51C, and 51D have their rotation speed and direction controlled by drive control signals from the drive control unit 3. The motor drives 51A, 51B, 51C, and 51D and the drive control unit 3 use a battery (not shown) as a power source for rotation drive and drive control. The camera, microphone, various sensors, displays, and control units described below are also powered by the battery. The projector described below is also powered by the battery. For example, a rechargeable secondary battery is used as the battery. A solar cell can also be used. When a solar cell is installed, the mobile projection device 1 has the advantage of being able to fly while charging with sunlight during the day outdoors.

In this example, the motor drivers 51A, 51B, 51C, and 51D are each independently controlled by a drive control signal from the drive control unit 3, allowing the mobile projection device 1 to perform various movement operations such as takeoff, landing, ascent (straight up, diagonally upward), descent (straight down, diagonally downward), right turn, left turn, forward, backward, right shift, and left shift, as well as attitude control such as the tilt angle relative to the vertical direction and position control of the hovering position.

In the mobile projection device 1 of this embodiment, a camera, microphone, various sensors, etc., which will be described later, are attached integrally with the drive control unit 3, and a housing 6 that houses a drive control device section 10 including a control section is formed. In this example, the housing 6 is configured to have an overall box-like shape.

Two legs 7A, 7B are attached to the housing 6 so as to face each other. In this example, the legs 7A, 7B are made of pipe members formed into a trapezoidal shape, and are formed so as to stably hold the mobile projection device 1 on the landing surface 8, as shown in FIG. 1(B). The shape and material of the legs are not limited to this, and various types are possible. For example, the legs may be made of wood or metal material and have four cylindrical legs at the four corners of the housing 6. Also, movable wheels may be attached to the legs to facilitate movement on the landing surface 8.

Above the rotors 52A, 52B, 52C, and 52D, in a position that does not interfere with the rotation of the rotors 52A, 52B, 52C, and 52D, the projector 9 is fixed to a support base 92 supported by a support pillar 91 that stands up from the top surface of the drive control unit 3 portion of the housing 6. A remote control transmission unit 93 for remotely controlling the projector 9 is attached to the support base 92. The remote control transmission unit 93 is attached to the support base 92 at a position where the remote control receiving unit (not shown) of the projector 9 can receive a remote control signal.

Projector 9 in this example has a playback section (not shown) for a DVD (Digital Versatile Disc) as an example of a storage medium. Projector 9 has the function of playing back image information stored on a DVD loaded in the playback section and projecting the image information as a projection image. 9L is a lens for projecting the projection image. Also, the playback sound of audio information stored in the DVD in correspondence with the image information is emitted from speakers 9SL and 9SR provided in projector 9.

A DVD stores multiple pieces of image information and audio information that have been prepared in advance to be provided to the viewer. Each of these pieces of image information and audio information can be cue-adjusted using a remote control signal.

In the following description, the side on which the projection lens 9L of the projector 9 is provided is referred to as the front side of the mobile projection device 1.

In this example, as shown in Figures 1(A) and (B), a camera CM1 is provided on the front of the housing 6, and a microphone MC is also provided. A speaker SP is also provided on the front of the housing 6. As shown in Figures 1(A) and (B), cameras CM2 and CM3 are provided on the left and right sides of the housing 6, respectively, and a camera CM4 is provided on the back of the housing 6. Furthermore, a camera CM5 is provided on the bottom of the housing 6, as shown in Figure 1(B).

The optical axis (corresponding to the shooting direction) of cameras CM1 to CM5 is perpendicular to the mounting surface of each camera CM1 to CM5, and each camera can shoot a specified angle of view with the optical axis direction as the center.

A drive control device unit 10 is provided inside the housing 6. FIG. 2 is a block diagram showing an example of the configuration of the drive control device unit 10 in the mobile projection device 1 of this embodiment. Note that the battery is omitted in FIG. 2.

As shown in FIG. 2, the drive control device unit 10 in this embodiment is configured by connecting an aerial flight drive unit 102, a gyro sensor 103, a geomagnetic sensor 104, an altitude sensor 105, an obstacle sensor 106, a movement space information memory 107, a current position detection unit 108, a flight drive signal generation unit 109, a position and attitude control signal generation unit 110, a group of cameras 111, a guidance message memory 112, an image recognition unit 113, a voice interface unit 114, a voice recognition unit 115, a projection image list memory 116, a projector remote control interface 117, and a remote control signal generation unit 118 to a control unit 101 consisting of a computer via a system bus 100.

The audio interface unit 114 is connected to a microphone MC and a speaker SP. The projector remote control interface 117 is also connected to a remote control transmission unit 93.

The aerial flight drive unit 102 supplies drive control signals to the motor drive units 51A, 51B, 51C, and 51D of the rotary wing mechanisms 5A, 5B, 5C, and 5D of the aerial flight mechanism unit 2, according to the control of the control unit 101.

The gyro sensor 103 detects changes in acceleration while the mobile projection device 1 is flying, and is used to detect the flight direction, speed, and attitude of the mobile projection device 1. The geomagnetic sensor 104 is used to detect the direction in which the mobile projection device 1 is flying. The altitude sensor 105 detects the altitude at which the mobile projection device 1 is located at a given time, and is composed of, for example, a barometric sensor.

The obstacle sensor 106 detects the presence of an obstacle by emitting light, infrared rays, millimeter waves, quasi-millimeter waves, microwaves, or ultrasound, and detecting the reflected waves from the obstacle. It also detects the time and attenuation between emitting light, infrared rays, or ultrasound and receiving the reflected waves, and is able to calculate the distance to the detected obstacle from the time and attenuation. In this embodiment, the obstacle sensor 106 is used to detect obstacles in the space in which the mobile projection device 1 is used (hereinafter referred to as the mobile space), such as indoor walls, chests of drawers, beds, desks, and the like, and obstacles such as utility poles, buildings, and trees in the outdoor mobile space, and to fly while avoiding collisions with them.

The moving space information memory 107 stores spatial information about the indoor or outdoor moving space in which the mobile projection device 1 is used. Examples of indoor moving spaces include art galleries, museums, and stores. Examples of outdoor moving spaces include limited-range spaces such as theme parks, amusement parks, zoos, concert venues, soccer stadiums, and baseball fields. Of course, the space is not limited to a limited range, and spatial information is stored in the moving space information memory 107 as a moving space as long as it is within the flight range of the mobile projection device 1, such as around a company, around a station, or around an airport.

In this embodiment, the memory of the control unit 101 of the mobile projection device 1 stores an application program for panoramic photography (e.g., Photosynth), and the mobile projection device 1 flies through the moving space and takes pictures in a 360-degree range at each location in the moving space using all or some of the cameras CM1 to CM5. The control unit 101 then uses the application program for panoramic photography to generate 3D image information for each point in the moving space from the captured image information, and stores the generated 3D image information in the moving space information memory 107.

In this case, in this example, the mobile projection device 1 defines a specific location in the mobile space in which it is used as a home position, and uses that location as a base for takeoff and landing. The specific location may be defined as a charging station, which is a normal waiting location.

The information stored in the moving space information memory 107 also includes the position information of the determined home position. In addition, in the moving space information memory 107, when the moving space is indoors, information on the length, width, and height of the room to be used is also stored in advance. Furthermore, when the moving space is indoors, structural information of the room to be used, such as beams, pipe spaces, and pillars, may also be stored in advance, and when the moving space is outdoors, the positions of utility poles, buildings, and trees may also be stored in advance.

The moving space information memory 107 also stores in advance the locations (position information) of indoor walls and outdoor building walls onto which the projector 9 can project a projection image, together with the length x width x height information of the walls. A screen onto which the projection image can be projected may be provided in advance indoors or outdoors, and the screen position may be stored in the moving space information memory 107.

In addition, in facilities such as kindergartens and nursery schools where the main audience is children, instructions to that effect can be input to the moving space information memory 107 so that the projection is performed at a lower position in accordance with the height of the children. In facilities such as nursing homes for the elderly and hospitals where there are many wheelchair users, instructions to that effect can also be input to the moving space information memory 107 so that the projection is performed at a lower position.

The current position detection unit 108 includes, for example, a GPS (Global Positioning System) receiver, and detects the latitude, longitude, and altitude of the current position of the mobile projection device 1. To obtain more accurate position information, the current position may be detected using radio waves from a mobile phone base station or radio waves from a Wi-Fi (Wireless Fidelity (registered trademark)) communication access point. Alternatively, all or some of the cameras CM1 to CM5 may be used to capture images of the surroundings of the mobile projection device 1, and the captured image information may be compared with the 3D image information stored in the moving space information memory 107 for image recognition, thereby grasping the relative position in the 3D image space and detecting the current position. To detect the current position after movement, the current position detection unit 108 also uses the gyro sensor 103, the geomagnetic sensor 104, and the altitude sensor 105.

When the control unit 101 issues a command based on the startup information to start flying from the base (home position) and moving through the air, the flight drive signal generation unit 109 calculates the direction and distance of movement to generate a flight drive signal for movement based on the base position information stored in the movement space information memory 107 and the position information of the current position detected by the current position detection unit 108.

Then, the flight drive signal generation unit 109 generates a flight drive signal for moving from the base position to the position instructed by the control unit 101 based on the calculated direction and distance, and using information from the gyro sensor 103, geomagnetic sensor 104, altitude sensor 105, etc., and further referring to images captured by cameras CM1 to CM5 of the camera group 111, and supplies this to the aerial flight mechanism unit 2 via the aerial flight drive unit 102. In this case, the flight drive signal consists of signals that drive each of the motor drive units 51A to 51D of the four rotary wing mechanisms 5A to 5D. The generated flight drive signal is supplied to each of the motor drive units 51A to 51D of the aerial flight mechanism unit 2 via the aerial flight drive unit 102.

The aerial flight mechanism unit 2 receives this flight drive signal and drives the rotors 52A-52D to rotate, moving by aerial flight from the base to a position instructed by the control unit 101, or from the current position to the base.

The position and orientation control signal generator 110 generates a position and orientation control signal based on the gyro sensor 103, the geomagnetic sensor 104, the altitude sensor 105, and the images captured by the cameras CM1 to CM5, as described below, to control the position and orientation of the device relative to the projection surface at the location where the determined projection image is to be projected so that the device is in an appropriate orientation and position (whether the optical axis of the lens 9L of the projector 9 is perpendicular to the wall surface onto which the projection image is projected, whether the front-to-back and left-to-right positions are appropriate, and whether the up-to-down position (height position) is appropriate, etc.).

In the mobile projection device 1 of this embodiment, as described below, the control unit 101 determines the location to which the projection image is to be projected depending on the number of viewers. Note that the concept of the location to which the projection image is to be projected includes the concept of different locations, such as different wall surfaces, as well as different positions on the same wall surface (positions that differ in the left-right direction or positions that differ in the height direction).

When the location where the projection image is to be projected is determined, the control unit 101 controls the flight drive signal generation unit 109 to generate a flight drive signal for hovering at the position (including the height position) where the projection image is to be projected at the determined location where the projection image is to be projected, and supplies this to the aerial flight mechanism unit 2 via the aerial flight drive unit 102. The position and attitude control signal generation unit 110 generates a signal for controlling the height position for hovering.

While hovering, the mobile projection device 1 projects and displays a projection image by the projector 9 at the determined location. If there is a space to land on, such as a desk, at a location suitable for projecting the projection image by the projector 9 at the determined location, the mobile projection device 1 may land at that location and project the projection image by the projector 9 at the determined location. After projection, the mobile projection device 1 may determine the surrounding situation and move up, down, left or right from the determined location to adjust the location, or the location itself may be changed. For example, if the viewer seems to have difficulty seeing, the mobile projection device 1 may move to a location where it is easier to see.

The camera group 111 consists of the cameras CM1 to CM5 described above. Each of the cameras CM1 to CM5 outputs captured image information of a moving image to the system bus 100. Identification information is added to the captured image information sent from each of the cameras CM1 to CM5 to the system bus 100 to identify which camera the captured image information came from. Note that the captured image information from each of the cameras CM1 to CM5 may not be captured image information of a moving image, but may be captured image information of still images taken at a predetermined time interval, for example, 0.5 second intervals.

The guidance message memory 112 stores guidance messages such as information about the mobile projection device 1 providing a service to provide projection images, guidance about the images to be projected by this service, and the possibility of selecting images.

The image recognition unit 113 recognizes people and their number from the captured image information captured by the cameras CM1 to CM5. The image recognition unit 113 also recognizes obstacles to be avoided during flight as described above. The image recognition unit 113 recognizes people and their number by performing pattern matching processing on the captured image information based on comparison images for detecting people and images of obstacles stored in an image memory (not shown), thereby recognizing the people and their number, as well as recognizing the obstacles. The flight drive signal generation unit 109 generates a flight drive signal that causes the recognized obstacle to be avoided and moved through the air.

In this embodiment, the image recognition unit 113 is also used to search for locations, such as indoor walls or outdoor building walls, onto which a projection image can be projected by the projector 9 and which are stored in the movement space information memory 107, from the images of the surrounding environment captured by the cameras CM1 to CM5.

The audio interface unit 114 has a function of supplying the audio signal picked up by the microphone MC to the audio recognition unit 115. The audio interface unit 114 also has a function of emitting audio from the speaker SP to convey a guidance message audio to the viewer in accordance with the control of the control unit 101. The microphone MC may be an omnidirectional microphone, but may also be a directional microphone in order to pick up only the audio uttered by the viewer.

The projection image list memory 116 stores a list of projection image information consisting of text information (e.g., title) indicating the contents of the image information stored on the DVD loaded in the projector 9, its playback order number, and the start and end points of the recording addresses on the DVD.

The DVD stores text information (e.g., titles) indicating the contents of the image information stored on the DVD, which is stored in the projection image list memory 116, and image information of a list of the playback order numbers, and the projection images in the list are provided to the viewer.

The audio guidance message stored in the guidance message memory 112 includes an explanation and guidance about the projection images in the list, as well as a guide message that allows the user to select a desired projection image from the list by its playback order number.

As described below, the control unit 101 receives a voice command for the playback order number of the desired projection image from the viewer through the microphone MC, and recognizes the voice in the voice recognition unit 115 to recognize the commanded playback order number. The control unit 101 then supplies a remote control signal from the remote control transmission unit 93 to the projector 9 so that the projection image of the recognized playback order number is provided as a projection image from the projector 9.

The projector remote control interface 117 is connected to the remote control transmission unit 93. The remote control signal generation unit 118 stores a remote control signal for DVDs, and the control unit 101 calls up the remote control signal for the projector 9 from the remote control signal generation unit 118 and sends it to the remote control transmission unit 93 via the projector remote control interface 117, so that it is transmitted to the remote control reception unit of the projector 9.

In addition, in FIG. 2, the processing functions of the flight drive signal generation unit 109, the position and attitude control signal generation unit 110, the image recognition unit 113, and the voice recognition unit 115 can also be realized by the control unit 101 as software processing functions.

[Operation flow of the mobile projection device 1 according to the first embodiment]
3 and 4 are flowcharts showing an example of the flow of the operation of the mobile projection device 1 of the first embodiment. In the following explanation, the control unit 101 will be described assuming that the control unit 101 realizes the processing functions of the flight drive signal generation unit 109, the position and attitude control signal generation unit 110, the image recognition unit 113, and the voice recognition unit 115 as software processing functions.

First, the control unit 101 puts the device into a standby state at the home position (step S101). In this standby state, the control unit 101 captures the visible range with the cameras CM1 to CM5, performs image recognition on the captured images, and monitors visitors to the museum, theme park, etc. in which the mobile projection device 1 is installed.

Then, the control unit 101 determines whether or not a visitor has been detected based on the image recognition results of the images captured by the cameras CM1 to CM5 (step S102), and if a visitor has not been detected, the control unit 101 returns to step S101 and maintains the standby state.

When a visitor is detected in step S102, the control unit 101 flies and moves to the vicinity of the detected visitor (step S103). The control unit 101 then confirms the number of viewers that has been detected or detected based on the image recognition results of the images captured by the cameras CM1 to CM5 (step S104).

Next, the control unit 101 determines whether there is a suitable location near the visitors to project the projection image based on the detected number of visitors, based on the image recognition results of the images captured by the cameras CM1 to CM5 and the information stored in the moving space information memory 107 (step S105). If it is determined in step S105 that there is no suitable location near the visitors to project the projection image based on the number of visitors, a guide message voice is emitted from the speaker SP to guide the visitors to an appropriate location based on the information stored in the moving space information memory 107, and the visitors are guided to the appropriate location (step S106). Note that the guidance method is not limited to voice, and the mobile projection device 1 can be equipped with lights such as LEDs (not shown) and guided by turning on or blinking the lights.

When it is determined in step S105 that a suitable location for projecting a projection image for the number of visitors is located near the visitors, and after guiding the visitors to the suitable location in step S106, the control unit 101 determines a suitable projection location and projection position according to the number of visitors, and a suitable screen size of the projection image according to the number of visitors (step S107). Then, the control unit 101 controls the projector 9 to project a projection image at the determined screen size at the projection position of the determined projection location, and controls the speaker SP to emit a guide message audio about the projected projection image (step S108).

At this time, the speakers 9SL, 9SR of the projector 9 emit audio associated with the projection image, and the control unit 101 transmits a remote control signal to the projector 9 to cause the speakers 9SL, 9SR to emit the audio at a volume that corresponds to the number of viewers who determined the screen size of the projection image. In other words, the volume of the audio from the speakers 9SL, 9SR is set to a relatively low volume when there are few viewers and the screen size of the projection image is small, and is set to a high volume that corresponds to the screen size when there are many viewers and the screen size is large. In this way, the volume of the audio from the speakers 9SL, 9SR is controlled to an appropriate volume that corresponds to the number of viewers.

Next, the control unit 101 monitors the voice recognition result of the voice picked up by the microphone MC, and determines whether or not a voice request from the viewer viewing the projected projection image has been detected (step S111 in FIG. 4). If it is determined in this step S111 that a voice request from the viewer has been detected, the control unit 101 sends a remote control signal to the projector 9 to change the projection image to a projection image according to the viewer's request (step S112).

When it is determined in step S111 that no voice request from the viewers has been detected, or after the projection image to be projected has been changed in step S112, the control unit 101 determines whether the number of viewers has changed (step S113). When it is determined in step S113 that the number of viewers has changed, the control unit 101 determines whether the projection location and/or screen size needs to be changed (step S114), and when it is determined that a change is necessary, the process returns to step S103, and the process from step S103 onwards is repeated. Note that various determination criteria can be set in step S114. For example, it is possible to set the screen size to be increased when the number of viewers increases, but not reduced when the number of viewers decreases. In addition, frequent changes in the projection location and screen size can be tiring, so it is also possible to limit the number of changes and the time for which the changes can be made.

If it is determined in step S113 that the number of viewers has not changed, or if it is determined in step S114 that there is no need to change the projection location and/or screen size, the control unit 101 determines whether to end the projection image provision service based on whether all of the image information stored on the DVD has been projected or whether a voice requesting termination from a viewer has been recognized (step S115).

If it is determined in step S115 that the service of providing projection images is not to be terminated, the control unit 101 returns the process to step S108 and repeats the processes from step S108 onward. Also, if it is determined in step S115 that the service of providing projection images is to be terminated, the control unit 101 sends an end remote control signal to the projector 9, and then flies back to the waiting location (step S116), returns the process to step S101, and enters a waiting state.

[Example of Usage of the Mobile Projection Device 1 of the First Embodiment]
Next, an example of a usage mode of the mobile projection device 1 of the first embodiment described above is shown in Fig. 5. The example of Fig. 5(A) shows a case where there is one visitor, and the example of Fig. 5(B) shows a case where there are many visitors.

As shown in FIG. 5(A), when there is one visitor HM, the control unit 101 of the mobile projection device 1 of this embodiment determines the projection location to be a position near the visitor HM at a height position that is approximately the same as the eye level of the visitor HM so that the visitor HM can easily view, and determines the screen size to be a screen size that allows one viewer to see the entire screen at a glance. In the example of FIG. 5(A), the projection location is the location PS1 of the determined screen size portion, near the viewer HM, at the eye level of the viewer HM on the wall surface WL.

The control unit 101 of the mobile projection device 1 then moves the device to the determined height position, controls it to hover at that height position, and controls the projector 9 using a remote control signal to change the screen size to the determined screen size through a combination of zoom processing by the lens 9L and the projection distance. As a result, the projection image Pj1 of the determined screen size is projected and displayed at the location PS1 on the wall surface WL.

When there are many visitors HM as shown in FIG. 5(B), the control unit 101 of the mobile projection device 1 takes into consideration that the viewers will be lined up in front of and behind the projection location PS, and determines the projection location to be higher (above) the horizontal line of sight of the viewers so that viewers at the back can also view the image, and determines the screen size to be larger than when there is only one person or a small number of people. In the example of FIG. 5(B), the projection location is the height position on the wall surface WL at which the many viewers HM can look up, and is set to location PS2 of the determined screen size.

The control unit 101 of the mobile projection device 1 then moves the device to the determined height position, controls the device 1 to hover at that height position, and controls the projector 9 using a remote control signal to combine zoom processing by the lens 9L and the projection distance to set the screen size to the determined size. As a result, the projection image Pj2 of the determined screen size is projected and displayed at location PS2 on the wall WL.

Note that, although there is only one viewer at the start of projection of the projection image, when the number of viewers increases, the projection location (projection position) and/or screen size are controlled to change in accordance with the increase in viewers, as explained in the flowchart above.

In that case, if the wall surface WL has an area corresponding to the upper part and a wide screen size as the projection location of the projection image, like the wall surface WL in the example of Figure 5, a different position on the same wall surface WL can be determined as the projection location. However, as described above, if a suitable area cannot be secured on the same wall surface WL as the projection location, it is necessary to move the projection location to another wall surface where a suitable projection location can be secured. In this case, the control unit 101 of the mobile projection device 1 of this embodiment also guides and guides the viewer about the movement by audio guidance messages, as described in the above flowchart.

Second Embodiment
In the first embodiment described above, the projection location (including different positions on the same wall) and the screen size of the projection image are changed according to the number of viewers, but the number of screens of the projection image to be projected may be changed. The second embodiment is an example of a case in which the number of screens of the projection image to be projected is changed according to the number of viewers, and is an example of a case in which the number of screens can be changed between one and two.

Figure 6 is a front view of the mobile projection device 1AB of the second embodiment, and corresponds to Figure 1 (B) of the first embodiment. A view of the mobile projection device 1AB of the second embodiment from above is similar to Figure 1 (A). In the mobile projection device 1AB of the second embodiment shown in Figure 6, the same parts as those in the mobile projection device 1 of the first embodiment described above are given the same reference numerals, and their description will be omitted.

As shown in FIG. 6, the mobile projection device 1AB of the second embodiment is fixed to a support base 92AB supported by a support column 91AB erected from the upper surface of the drive control unit 3 portion of the housing 6. A projector 9A and a projector 9B are attached to the support base 92AB so as to be arranged in two tiers, one above the other. Remote control transmission units 93A and 93B for remotely controlling the projectors 9A and 9B attached to the support base 92AB are also attached. The remote control transmission units 93A and 93B are attached to the support base 92AB at positions where the remote control receiving units (not shown) of the projectors 9A and 9B can receive remote control signals. The rest of the configuration is the same as that of the first embodiment.

The drive control device section of the mobile projection device 1AB of this second embodiment is not shown, but is substantially the same as the configuration of the first embodiment in FIG. 2. However, it differs from the configuration in FIG. 2 in that the remote control transmission units 93A and 93B are each connected to the control unit 101 via a projector remote control interface.

In the mobile projection device 1AB of the second embodiment, when there is one or a small number of viewers (even if there are multiple rows, the number of viewers is such that the viewers in the front rows do not get in the way of the viewers), one projection image PjA (see FIG. 7) is projected by the lower projector 9A. When there are many viewers (even if there are multiple rows, the number of viewers in the front rows does not get in the way of the viewers), as shown in FIG. 7, a projection image PjB is projected not only by the lower projector 9A but also by the upper projector 9B. This allows viewers in the rear to view the projection image PjB projected by the upper projector 9B without getting in the way of the viewers in the front rows.

It goes without saying that the screen size of the projection image can be changed in the mobile projection device 1AB of the second embodiment as well. In that case, it goes without saying that the screen size of the projection image PjA by the projector 9A on the lower level and the screen size of the projection image PjB by the projector 9B on the upper level can be changed independently.

In the second embodiment described above, the two projectors 9A and 9B face in the same optical axis direction, but they may be arranged so that their optical axes face in different directions. For example, one projector may be installed so that its optical axis direction faces the front direction, while the other projector may be installed so that its optical axis direction faces upward (toward the ceiling) perpendicular to the front direction, or in the left-right direction.

In the second embodiment described above, two projectors are used, but three or more projectors may be used. For example, the projectors may be installed in three tiers: top, middle, and bottom.

[Third embodiment]
The third embodiment is another example of a case where the number of screens for projecting a projection image is changed according to the number of viewers, and the number of screens can be changed between one and three.

Figure 8 is a front view of the mobile projection device 1CDE of the third embodiment, and corresponds to Figure 1 (B) of the first embodiment. A view of the mobile projection device 1CDE of the third embodiment from above is omitted. In the mobile projection device 1CDE of the third embodiment shown in Figure 8, the same parts as those in the mobile projection device 1 of the first embodiment described above are given the same reference numerals, and their description is omitted.

As shown in FIG. 6, the mobile projection device 1CDE of the third embodiment is fixed to a support base 92CDE supported by a support column 91CDE erected from the upper surface of the drive control unit 3 portion of the housing 6. Three projectors, 9C, 9D, and 9E, are attached to the support base 92CDE so that they are arranged side-by-side on the same plane of the support base 92CDE. Of course, the arrangement and attachment methods are not limited to this. For example, they do not have to be attached on the same plane, and they do not have to be arranged side-by-side.

Remote control transmitters 93C, 93D, and 93E are attached to the support base 92CDE to remotely control the projectors 9C, 9D, and 9E that are arranged side by side and attached to the support base 92CDE. The remote control transmitters 93C, 93D, and 93E are attached to the support base 92CDE at positions where the remote control receivers (not shown) of the projectors 9C, 9D, and 9E can receive remote control signals. The rest of the configuration is the same as in the first embodiment.

The drive control device section of the mobile projection device 1CDE of this third embodiment is not shown, but is substantially the same as the configuration of the first embodiment in FIG. 2. However, it differs from the configuration in FIG. 2 in that the remote control transmission sections 93C, 93D, and 93E are each connected to the control section 101 via a projector remote control interface.

In the mobile projection device 1CDE of the third embodiment, when there is one or a small number of viewers and they are relatively concentrated in one place, the central projector 9C projects the projection image PjC. When there are many viewers and they are scattered all over the place, as shown in Fig. 9, a two-screen projection image PjC by the central projector 9C and one of the projection images PjD and PjE by the projectors 9D and 9E on either side of the central projector 9C, or a three-screen projection image PjC by the central projector 9C and both of the projection images PjD and PjE by the projectors 9D and 9E on either side of the central projector 9C, is used. The control unit 101 determines whether to display two or three screens based on the image recognition results of the images captured by cameras CM1 to CM5, depending not only on the number of viewers but also on their concentration (dispersion).

This makes it possible for all viewers to view the image clearly using two or three projection images, even when the viewers are in multiple groups, each group concentrating and therefore scattered, or when the viewers are single people or multiple couples and are scattered. In addition to image recognition of the captured image, it is also possible to detect the line of sight of each viewer, grasp the viewer's concentration (dispersion) and consider the screen composition.

It goes without saying that the screen size of the projection images PjC, PjD, and PjE can be changed in the mobile projection device 1CDE of the third embodiment. In that case, it goes without saying that each of the projection images PjC, PjD, and PjE can be changed independently.

In the third embodiment described above, the three projectors 9C, 9D, and 9E face the same optical axis direction, but they may be arranged so that their optical axes face different directions. For example, one projector may be installed so that its optical axis direction faces the front direction, while the other two projectors may be installed so that their optical axes face the upward direction (toward the ceiling) perpendicular to the front direction, or the left and right directions.

In addition, in the third embodiment described above, an example was given in which three projectors were used, but the number of projectors may be two or four or more.

Furthermore, two tiers of projectors, one above the other as in the second embodiment described above, may be installed on the left and right.

[Fourth embodiment]
In the above-mentioned embodiment, the mobile projection device waits at a position where it can see the visitors, and when it detects a visitor, it flies to the side of the detected visitor and provides a projection image. In the fourth embodiment described below, in response to a call from a viewer, the mobile projection device detects the location of the viewer who made the call, moves to that location, and provides a projection image.

The fourth embodiment of the mobile projection device described below has a configuration that takes into account the case where the viewer is a foreigner.

Before describing an example of the configuration of the mobile projection device of this fourth embodiment, an example of the environment in which the mobile projection device of this fourth embodiment is used will be described with reference to FIG. 10.

The example in FIG. 10 assumes that the mobile projection device 1F of the fourth embodiment is used in an art museum to provide various kinds of guidance through projected images. The art museum in this example has multiple exhibition spaces separated by walls. That is, as shown in FIG. 10, the art museum in this example has multiple exhibition spaces consisting of a Western painting space 201, a Japanese painting space 202, a calligraphy and painting space 203, a sculpture space 204, a special exhibition space 205, and a pottery space 206, as well as an entrance hall 207. Visitors can purchase tickets at the ticket booth 208 outside and present the tickets at gate 209 to enter the entrance hall 207 through the gate 209.

A standby base 210 for the mobile projection device is provided in the entrance hall 207, and this standby base 210 is configured to hold multiple mobile projection devices 1F of the fourth embodiment. Of course, the mobile projection device 1F can be configured to have one standby device, or two or more, for example, 100 or more, on standby.

In each of the Western painting space 201, Japanese painting space 202, calligraphy space 203, sculpture space 204, special exhibition space 205, and pottery space 206, as well as in the entrance hall 207, there are call posts 211, 212, 213, 214, 215, 216, and 217 through which visitors can send call signals to call the mobile projection device 1F of the fourth embodiment.

Call posts 211, 212, 213, 214, 215, 216, and 217 each have a call button 211BT, 212BT, 213BT, 214BT, 215BT, 216BT, and 217BT. When a visitor (viewer) presses a call button 211BT, 212BT, 213BT, 214BT, 215BT, 216BT, or 217BT, the call post with the pressed call button sends out a call signal that includes identification information that identifies the call post.

As described below, the mobile projection device 1F is equipped with a communication unit that receives call signals from the call posts 211-217. The mobile projection device 1F then recognizes which call post the call signal is from based on the identification information contained in the received call signal, and flies to the side of a visitor (hereinafter referred to as a viewer) in the space where the recognized call post is installed, and provides a projection image. In this example, the call posts 211-217 and the multiple mobile projection devices 1F are connected by a wireless LAN conforming to the Wi-Fi (registered trademark) standard.

Next, an example of the configuration of a mobile projection device 1F of the fourth embodiment will be described. The mobile projection device 1F of the fourth embodiment described below is mechanically configured in the same manner as the mobile projection device 1 of the first embodiment, which is equipped with one projector. The mobile projection device 1F of the fourth embodiment has a partly different configuration of the drive control device unit from the mobile projection device 1 of the first embodiment. In the following description of the mobile projection device 1F of the fourth embodiment, the same parts as those of the first embodiment are given the same reference numerals, and detailed description thereof will be omitted.

Fig. 11 is a block diagram showing an example of the configuration of a drive control device unit 10F of a mobile projection device 1F of the fourth embodiment. As shown in Fig. 11, the drive control device unit 10F includes a communication unit 121 and a foreign language determination unit 122.

The communication unit 121 has a wireless communication function for performing communication for the wireless LAN described above. When the communication unit 121 receives a call signal from one of the call posts 211 to 217, it extracts the identification information of the call post contained in the received signal and sends it to the control unit 101 via the system bus 100.

The moving space information memory 107 of the drive control device unit 10F stores moving space information consisting of the multiple exhibition spaces 201-206 and entrance hall 207 of the art museum shown in FIG. 10, as well as corresponding information between the identification information and position information of each of the call posts 211-217 installed in each of the exhibition spaces 201-206 and entrance hall 207.

When the control unit 101 receives the identification information of the call post from the communication unit 121, it determines whether the call signal was received from the exhibition space 201-206 or the entrance hall 207 based on the correspondence information between the identification information and position information of the call post 211-217 stored in the moving space information memory 107. The control unit 101 then causes the flight drive signal generation unit 109 to generate a flight drive signal for flying to either the exhibition space 201-206 or the entrance hall 207 where the recognized call post is located, and controls the aerial flight mechanism unit 2 to execute the flight movement. Note that the control unit 101 of the mobile projection device 1F that has received the call signal and started moving in response to the call controls the communication unit 121 to a sleep state or a stopped state so as not to receive other call signals from the start of movement until returning to the standby base 210.

When the foreign language determination unit 122 moves close to the viewer to provide a projection image, it determines which language is being used if the viewer is a foreigner, based on the voice recognition results of the voice recognition unit 115 for the voice signal picked up by the microphone MC.

The DVD loaded into the mobile projection device 1F of this fourth embodiment stores not only image information and audio information in Japanese, but also image information and audio information of the same program content in, for example, English, Spanish, French, German, Chinese, and Korean, associated with identification information for the language used. Note that as program content, image information and audio information of guidance to be provided to viewers in each of the exhibition spaces 201-206 and the entrance hall 207 are stored in association with identification information for the exhibition spaces 201-206 and the entrance hall 207.

If the language used by the viewer is determined to be a foreign language other than Japanese, but does not match any of the prepared languages, the viewer will be asked to select the language in which the content should be provided, and the content will be provided in the selected language.

In the mobile projection device 1F of this fourth embodiment, the projection image list memory 116 stores the identification information of the image information and audio information of the guide to be provided to the viewer in each of the exhibition spaces 201-206 and the entrance hall 207, and the corresponding information of the address information on the DVD. It also stores the identification information of each of the image information and audio information corresponding to a plurality of languages used for the image information and audio information of the same program content, and the corresponding information of the storage address on the DVD.

Other than that, the configuration is the same as each part of the drive control device unit 10 of the mobile projection device 1 of the first embodiment shown in FIG. 2. The processing function of the foreign language determination unit 122 can be realized by the control unit 101 as a software processing function.

[Operation flow of the mobile projection device 1F according to the fourth embodiment]
12 and 13 are flowcharts showing an example of the flow of the operation of the mobile projection device 1F of the fourth embodiment. In the following explanation, the control unit 101 will be explained on the assumption that the control unit 101 realizes the processing functions of the flight drive signal generation unit 109, the position and attitude control signal generation unit 110, the image recognition unit 113, the voice recognition unit 115, and the foreign language determination unit 122 as software processing functions.

First, the control unit 101 sets the device in a standby state at the home position (step S201). In this standby state, the control unit 101 sets the communication unit 121 in an operating state and monitors the communication unit 121 for reception of a call signal.

Then, the control unit 101 determines whether or not it has detected the reception of a call signal through the communication unit 121 (step S202), and if it has not detected the reception of a call signal, it returns to step S201 and maintains the standby state.

When the control unit 101 detects the reception of a call signal in step S202, the control unit 101 recognizes the identification information of the call post that sent the received call signal, and detects and recognizes the location of the call post (step S203). The control unit 101 then moves to one of the exhibition spaces 201 where the recognized call post is located, or to the entrance hall 207 (step S204). Prior to this movement, the control unit 101 controls the communication unit 121 to a sleep state or a stopped state so that it does not respond to other call signals.

When the viewer moves to one of the exhibition spaces 201 where the call post that sent the call signal is located, or to the entrance hall 207, the control unit 101 recognizes the called viewer from the images captured by the cameras CM1 to CM5, and emits an audio guidance message from the speaker SP to guide the recognized viewer (including multiple people) to the location where the projection image will be projected, and guides the viewer to the projection location (step S205).

Then, the control unit 101 detects the number of viewers or confirms the number of viewers that have been detected based on the image recognition results of the images captured by the cameras CM1 to CM5 (step S206).

Next, the control unit 101 determines an appropriate projection location and projection position according to the number of people, and an appropriate screen size of the projected image according to the number of people (step S207). Next, the control unit 101 determines the language used by the viewer from the voice recognition results of the voice information picked up by the microphone MC, and selects the language used by the voice to be provided (step S208). As described above, when the language used by the viewer cannot be determined, the viewer is asked to select the language used, as described above. This selection of the language used by the viewer can also be performed by voice recognition.

Next, the control unit 101 controls the device to project the projection image at the determined screen size at the projection position of the determined projection location, and emits an audio guidance message about the projected projection image from the speaker SP (step S209). The audio guidance message used at this time is in the language selected in step S208. The volume of the audio provided from the speakers 9SL, 9SR of the projector 9 together with the display of the projection image is set to a volume according to the number of viewers (or the screen size of the projection image), as in the first embodiment.

Next, the control unit 101 monitors the voice recognition result of the voice picked up by the microphone MC and determines whether or not a desired voice from the viewer viewing the projected projection image has been detected (step S211 in FIG. 13). If it is determined in this step S211 that a desired voice from the viewer has been detected, the control unit 101 sends a remote control signal to the projector 9 to change the projection image to a projection image according to the viewer's request (step S212).

When it is determined in step S211 that no voice request from the viewers has been detected, or after the projection image to be projected has been changed in step S212, the control unit 101 determines whether the number of viewers has changed (step S213). When it is determined in step S213 that the number of viewers has changed, the control unit 101 determines whether the projection location and/or screen size needs to be changed (step S214), and when it is determined that a change is necessary, the process returns to step S207, and the processes from step S207 onwards are repeated. Note that the criteria for determination in step S214 can be set in various ways, similar to the criteria for determination in step S114.

If it is determined in step S213 that the number of viewers has not changed, or if it is determined in step S214 that there is no need to change the projection location and/or screen size, the control unit 101 determines whether to end the projection image provision service based on whether all of the image information stored on the DVD has been projected or whether a voice requesting termination from a viewer has been recognized (step S215).

If it is determined in step S215 that the service of providing projection images is not to be terminated, the control unit 101 returns the process to step S209 and repeats the processes from step S209 onwards. Also, if it is determined in step S215 that the service of providing projection images is to be terminated, the control unit 101 sends an end remote control signal to the projector 9, flies back to the waiting location (step S216), and returns the communication unit 121, which was in a sleep or stopped state, to an operating state, thereby restoring it to a state in which it can receive a call signal (step S217). The control unit 101 then returns the process to step S201 and enters a waiting state.

According to the fourth embodiment described above, the mobile projection device 1F can respond to calls from locations where it cannot see itself, fly to the location, and provide projection images to viewers at a projection location and screen size that corresponds to the number of viewers. In addition, if the viewers are foreigners and can use a pre-prepared language, it is possible to provide audio guidance messages and audio information accompanying the projection images in that language.

[Other embodiments or modifications]
In the above example, the projection location to be determined is not considered to be easy to view at the location. However, for example, when the location is outdoors and exposed to direct sunlight, the projection image may be difficult to view even if it is projected at the location. The control unit 101 may be configured to take such a case into consideration. That is, the control unit 101 detects the brightness (illuminance) of the part where the image is to be projected, such as the wall surface of the location to be determined as the projection location of the projection image, and determines whether the brightness is equal to or lower than a predetermined threshold value that takes into consideration the ease of viewing of the projection image. If the brightness of the location is equal to or lower than the predetermined threshold value, the control unit 101 determines the location as the projection location and uses it as the location to project the projection image. On the other hand, if the brightness of the location is brighter than the predetermined threshold value, the control unit 101 does not determine the location as the projection location, and searches for another suitable projection location.

When there are parts of different brightness within the same wall, if the area of the part where the brightness is below the predetermined threshold is larger than the screen size of the projection image, that part can be determined as the projection location. For example, if a wall is in a position where it is hit by direct sunlight, but there is a shadow area of a predetermined size where the brightness is below the threshold due to the shadow of an adjacent building, the projection image can be projected into that shadow area, and the shadow area can be determined as the projection location.

In the above embodiment, the projector in the mobile projection device is fixed directly to the support base so as not to move. However, the projector may be mounted and fixed on a rotating base that rotates horizontally and is provided on the support base. In that case, rather than moving or rotating the mobile projection device itself horizontally to move the projection position of the projection image horizontally, the mobile projection device itself can be kept in a hovering state while the rotating base provided on the support base is rotated to rotate the projector, thereby moving the projection position of the projection image horizontally.

In addition, a tilt mechanism may be provided on the support stand that can change the direction of the projector's optical axis to face downward (in the direction of the dip angle) from a plane parallel to the bottom surface of the support stand, or upward (in the direction of the elevation angle) from a plane parallel to the bottom surface of the support stand. By fixing the projector to this tilt mechanism, the control unit 101 may control the tilt mechanism to move the projection position of the projection image in the vertical direction.

In the above embodiment, the projector 9 is equipped with a DVD drive to reproduce image information and audio information stored on a DVD and provide a projection image and accompanying audio, but it is not limited to a DVD drive and may be equipped with a BD (Blu-ray Disc), HDD (hard disk drive), or SSD (solid state drive). It may also be equipped with a flash memory such as a USB or SD card. Furthermore, the image information and audio information may be obtained from a cloud on the Internet.

In the above embodiment, the projector 9 is provided separately from the housing 6, but it may of course be incorporated into the housing 6. In that case, the remote control transmitter and projector remote control I/F attached to the housing 6 and the remote control receiver attached to the projector 9 are not necessary.

In the above embodiment, the projector has a function of reproducing image information and audio information from a storage medium, but this is not limited to this. For example, the mobile projection device can be configured to receive projection image information and audio information sent from the outside via wireless communication, project them with the projector, and also reproduce the audio. In this case, the projection image information and audio information sent from the outside may be selected and received by the mobile projection device from among those sent in broadcast format, or the mobile projection device may be configured to make a request to the providing server and obtain the projection image information and audio information in response to the request from the providing server.

In the above embodiment, the aerial flight mechanism 2 of the mobile projection device is described as a helicopter-type mechanism having four rotary wing mechanisms, but the number of rotary wing mechanisms may be three or less or five or more. Furthermore, the mechanism is not limited to a helicopter-type mechanism, and may be an airplane-type mechanism, for example.

In the above embodiment, the camera group 111 has five cameras and one microphone, but the number is not limited to this number. There are also various possible positions for installing the cameras and microphones. The cameras may be standard cameras, wide-angle cameras, fisheye cameras, or 360-degree cameras. They may also be telephoto cameras, infrared cameras, or the like. Of course, these cameras may be used in combination.

Of course, there may also be multiple gyro sensors, geomagnetic sensors, altitude sensors, and obstacle sensors.

In the case of a mobile projection device that is expected to be used outdoors, it is desirable to make it waterproof. If the waterproof specifications are not sufficient, the mobile projection device needs to take defensive measures such as waiting in a place that is not exposed to rain or snow during rain or snowfall and not flying. In addition, if the mobile projection device experiences rain or snow during flight, or detects the possibility of rain or snowfall, the mobile projection device will promptly land in a place that is not exposed to rain or snow and ask for instructions from the communicator. In this case, rain or snow is detected by a rain sensor or snow sensor. In addition, if the mobile projection device is equipped with an umbrella, the umbrella may be used during rain or snowfall. In addition, the mobile projection device may be made capable of measuring wind force or wind speed, and may not fly outdoors when the wind is strong because there is a high possibility of an accident occurring.

Of course, there are many other possible modifications to the mechanism of the mobile projection device.

Reference Signs List 1, 1AB, 1CDE, 1F...mobile projection device, 2...aerial flight mechanism, 9, 9A, 9B, 9C, 9D, 9E...projector, 101...control unit, 111...camera, 113...image recognition unit

Claims (21)

an aerial flight mechanism for flying in the air;
a projector unit for projecting an image;
a speaker that outputs a sound related to the image;
a camera for photographing a viewer viewing the projected image;
a number-of-viewers detection unit that detects the number of viewers from the captured image of the camera;
a control unit that controls a volume of the sound emitted from the speaker in accordance with the number of viewers detected by the number-of-viewers detection unit;
A communication means for receiving call information;
Equipped with
Based on information for specifying a location included in the call information, the projector moves to a location near a viewer who is in a place where the call information is transmitted, and projects the image by the projector unit.
A mobile projection device comprising: A moving space information memory is provided for storing information on a moving space in which the device itself should fly and move, the moving space being divided into a plurality of mutually non-overlapping partial space regions;
the moving space information memory stores information on a call device that transmits the call information and is installed in each of the partial space regions, and information on the partial space regions in which the call device is installed;
The mobile projection device according to claim 1, characterized in that the information for identifying the location included in the call information is information for identifying in which of the subspace areas the call device that sent the call information is installed . an aerial flight mechanism for flying in the air;
a projector unit for projecting an image;
a speaker that outputs a sound related to the image;
a camera for photographing a viewer viewing the projected image;
a number-of-viewers detection unit that detects the number of viewers from the captured image of the camera;
a control unit that controls a volume of the sound emitted from the speaker in accordance with the number of viewers detected by the number-of-viewers detection unit;
means for detecting rain or snow, or the possibility of rain or snow;
a means for moving the device to a place where it is not exposed to rain or snow when the device detects rainfall or snowfall or the possibility of rainfall or snowfall;
A mobile projection device comprising: an aerial flight mechanism for flying in the air;
a projector unit for projecting an image;
a speaker that outputs a sound related to the image;
a camera for photographing a viewer viewing the projected image;
a number-of-viewers detection unit that detects the number of viewers from the captured image of the camera;
a control unit that controls a volume of the sound emitted from the speaker in accordance with the number of viewers detected by the number-of-viewers detection unit;
means for detecting rain or snow, or the possibility of rain or snow;
Umbrella and
a means for controlling the use of the umbrella when the rainfall or snowfall is detected or the possibility of the rainfall or snowfall is detected;
A mobile projection device comprising: A mobile projection device as described in any one of claims 1 to 4, characterized in that the control unit determines the size of the image to be projected in accordance with the number of viewers detected by the number of viewers detection unit, controls the projector unit to display an image of the determined size, and controls the volume of the sound emitted from the speaker in accordance with the size of the image to be projected. The mobile projection device according to any one of claims 1 to 5, characterized in that, when the presence of the viewer is detected from the image captured by the camera, the mobile projection device moves to a position close to the detected viewer and projects an image using the projector unit. 7. The mobile projection device according to claim 1, further comprising: a projection control unit that controls a volume of the sound emitted from the speaker according to a change in the number of viewers while the image is being projected. The mobile projection device according to any one of claims 1 to 7, characterized in that, when the number of viewers is detected by the number-of-viewers detection unit to be a large number equal to or greater than a predetermined number, the control unit controls the projection of the image to a larger size than when the number of viewers is one or a small number less than the predetermined number, and/or controls the volume of the sound emitted from the speaker to be increased. a microphone for collecting the voice of the viewer; and a foreign language determination unit for determining a foreign language used by the viewer from the voice of the viewer collected by the microphone;
the projector unit is provided with image information in a plurality of foreign languages as image information of the image to be projected,
9. The mobile projection device according to claim 1 , further comprising a unit for selecting the image information to be projected by the projector unit based on the foreign language determined by the foreign language determination unit. a microphone for collecting the voice of the viewer; and a foreign language determination unit for determining a foreign language used by the viewer from the voice of the viewer collected by the microphone;
the projector unit is provided with audio information in a plurality of foreign languages as audio information accompanying the image to be projected,
The mobile projection device according to any one of claims 1 to 9 , further comprising a means for selecting the audio information to be provided to the viewer in association with the image, based on the foreign language determined by the foreign language determination unit. The mobile projection device according to any one of claims 1 to 10 , further comprising a solar cell, and capable of flying while being charged by sunlight. A microphone for picking up the voice of the viewer;
a means for recognizing a request of the viewer based on a voice recognition result of the voice of the viewer picked up by the microphone;
A control means for controlling the projection of the image according to the recognized request;
12. The mobile projection device according to claim 1, wherein the projection device is a projection type projection device having a projection surface. 9. The mobile projection device according to claim 1, wherein the projector section has a function of reproducing image information of the image to be projected from a storage medium. 9. The mobile projection device according to claim 1, wherein image information of the image projected by the projector section is transmitted from an external device in a broadcast format. 9. The mobile projection device according to claim 1, further comprising a function for requesting and acquiring image information of the image projected by the projector unit from a server providing the image information. 10. The mobile projection device according to claim 1, wherein the speaker has a function of reproducing audio information accompanying the image projected from a storage medium. 10. The mobile projection device according to claim 1, wherein audio information accompanying the image output by the speaker is transmitted from an external device in a broadcast format. 10. The mobile projection device according to claim 1 , further comprising a function of requesting and acquiring audio information accompanying the image output by the speaker from a server providing the audio information. A computer provided in a mobile projection device including an aerial flight mechanism for flying in the air, a projector for projecting an image, a speaker for emitting sound related to the image, a camera for photographing a viewer viewing the projected image, and a communication means for receiving call information,
a number-of-viewers detection means for detecting the number of viewers from the image captured by the camera;
a means for controlling a volume of the sound emitted from the speaker in accordance with the number of viewers detected by the number-of-viewers detection means;
a means for controlling the aerial flight mechanism unit to move to the vicinity of a viewer who is in a place where the call information is transmitted, based on information for specifying a location included in the call information, and for controlling the projector unit to project the image;
A program for a mobile projection device to function as a A computer provided in a mobile projection device including an aerial flight mechanism for flying in the air, a projector for projecting an image, a speaker for emitting sound related to the image, a camera for photographing a viewer viewing the projected image, and a means for detecting rainfall or snowfall,
a number-of-viewers detection means for detecting the number of viewers from the image captured by the camera;
a control means for controlling a volume of the sound emitted from the speaker in accordance with the number of viewers detected by the number-of-viewers detection means;
a means for controlling the flight mechanism unit so as to move the device to a location that is not exposed to rain or snow when rainfall or snowfall is detected;
A program for a mobile projection device to function as a A computer provided in a mobile projection device including an aerial flight mechanism for flying in the air, a projector for projecting an image, a speaker for emitting sound related to the image, a camera for photographing a viewer viewing the projected image, a means for detecting rainfall or snowfall, and an umbrella,
a number-of-viewers detection means for detecting the number of viewers from the image captured by the camera;
a control means for controlling a volume of the sound emitted from the speaker in accordance with the number of viewers detected by the number-of-viewers detection means;
a control means for controlling the use of the umbrella when the rainfall or snowfall is detected;
A program for a mobile projection device to function as a

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