Projection system, projection method and program

Abstract

To provide a projection system, a projection method and a program which can more easily switch a state of the projection device according to the position of an object.SOLUTION: A projection system comprises a processing unit which determines whether or not an object is located within a first range where a first projection surface reflected on a mirror is visible and whether or not the object is located within a second range where a second projection surface is directly visible on the basis of the detection result of the object having a visibility function by a detection device, causes a projection device to project a first image recognized that it is in the normal direction when being reflected on the mirror to the first projection surface when determining that the object is located within the first range, and causes the projection device to project a second image recognized that it is in the normal direction when being directly viewed to the first projection surface when determining that the object is located within the second range.SELECTED DRAWING: Figure 4

Description

Technical Field

[0001] The present invention relates to a projection system, a projection method, and a program.

Background Art

[0002] Conventionally, a technique for adjusting the projection position of an image by a projection device such as a projector according to the position of an object (for example, a person) detected by a detection device such as a sensor is known. For example, Patent Document 1 discloses a technique for allowing an object to easily view an image by projecting the image at a position separated from the detected position of the object by a predetermined distance in the forward direction of the traveling direction of the object. The adjustment of the projection position is performed by operating a drive unit such as a motor to change the orientation of the projection device each time.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, when the detected position of the object changes significantly (for example, when the position of the object changes to the opposite side across the projection device), in order to project at an appropriate projection position, it is necessary to significantly change the state of the projection device (in the above prior art, the orientation), and it takes a long time until the projection at the appropriate projection position is started. As described above, the above prior art has a problem that it is not easy to switch the state of the projection device according to the position of the object.

[0005] An object of the present invention is to provide a projection system, a projection method, and a program that can more easily switch the state of a projection device according to the position of an object.

Means for Solving the Problems

[0006] To solve the above problems, the present invention One The projection system is Based on the detection result of the detection device for an object with a visibility function, it is determined whether the object is located in a first range where the first projection surface reflected in the mirror is visible, and whether the object is located in a second range where the first projection surface is directly visible. It is determined that the subject is located within the first range. Furthermore, it is not determined that the object is located within the second range. In this case, the projection device projects a first image, which is recognized as being in the correct orientation when reflected in the mirror, onto the first projection surface. The object is not determined to be located within the first range and If it is determined that the object is located within the second range, the projection device projects a second image onto the first projection surface that is recognized as being in the correct orientation when viewed directly. 、 If it is determined that the object is located in the first range and also in the second range, the projection device projects a third image onto a second projection surface that is directly visible to the object located in the first range and the object located in the second range, the third image being recognized as being in a normal orientation when directly viewed. It is equipped with a processing unit.

[0007] Furthermore, in order to solve the above problems, the present invention One The projection method is, A projection method performed by a computer in a projection system, Based on the detection result of the detection device for an object with a visibility function, it is determined whether the object is located in a first range where the first projection surface reflected in the mirror is visible, and whether the object is located in a second range where the first projection surface is directly visible. It is determined that the subject is located within the first range. Furthermore, it is not determined that the object is located within the second range. In this case, the projection device projects a first image, which is recognized as being in the correct orientation when reflected in the mirror, onto the first projection surface. The object is not determined to be located within the first range and If it is determined that the object is located within the second range, the projection device projects a second image onto the first projection surface that is recognized as being in the correct orientation when viewed directly. 、 If it is determined that the object is located in the first range and also in the second range, the projection device projects a third image onto a second projection surface that is directly visible to the objects located in the first range and the objects located in the second range, the third image being recognized as being in the normal orientation when directly viewed. .

[0008] Also, to solve the above problems, the program according to the present invention causes a computer of the projection system to perform a process of determining whether the object having the visual recognition function is located within a first range where the first projection surface reflected by the mirror can be visually recognized and whether the object is located within a second range where the first projection surface can be directly visually recognized, based on the detection result of the object by the detection device, when it is determined that the object is located within the first range Furthermore, it is not determined that the object is located within the second range. to cause the projection device to project a first image recognized as having a normal orientation when reflected by the mirror onto the first projection surface, The object is not determined to be located within the first range and when it is determined that the object is located within the second range, to cause the projection device to project a second image recognized as having a normal orientation when directly visually recognized onto the first projection surface, If it is determined that the object is located in the first range and also in the second range, the projection device performs a process of projecting a third image, which is recognized as being in a normal orientation when directly viewed, onto a second projection surface that is directly visible to the object located in the first range and the object located in the second range. and to execute.

Advantages of the Invention

[0009] According to the present invention, it is possible to more easily switch the state of the projection device according to the position of the object.

Brief Description of the Drawings

[0010] [Figure 1] It is a diagram showing the configuration of the projection system of the first embodiment. [Figure 2] It is a diagram showing the mechanism of the projector for attachment to the ceiling and adjustment of the projection direction. [Figure 3] It is a block diagram showing the functional configuration of the control device, the projector, and the detection device. [Figure 4] It is a diagram for explaining the projection operation of the first image when a person is within the first range. [Figure 5] It is a diagram for explaining the projection operation of the second image when a person is within the second range. [Figure 6] It is a diagram for explaining the projection operation of the third image when a person is within the first range and the second range. [Figure 7]This is a flowchart for explaining the control procedure of the projection control process. [Figure 8] This is a flowchart for explaining the control procedure of the image projection process. [Figure 9] This is a flowchart for explaining the control procedure of the projection control process according to the modified example. [Figure 10] This is a diagram showing the configuration of the projection system according to the second embodiment. [Figure 11] This is a diagram showing the room in the second embodiment. [Figure 12] This is a flowchart for explaining the control procedure of the projection control process according to the second embodiment.

Embodiments for Carrying Out the Invention

[0011] Hereinafter, embodiments according to the present invention will be described based on the drawings.

[0012] (First Embodiment) <Overview of the Projection System> FIG. 1 is a diagram showing the configuration of a projection system 1 according to the first embodiment. The projection system 1 comprises a control device 10, a projector 20 (projection device), and a detection device 30. The projector 20 and the detection device 30 are each wirelessly or wiredly connected to the control device 10, enabling them to send and receive data with the control device 10. The projection system 1 of this embodiment is installed in a room 100. The room 100 has a ceiling 61, a floor 62, walls 63-65, a corridor 66, a mirror 50, etc., and is, for example, the entrance to a house. Walls 63-65 are perpendicular to the ceiling 61 and the floor 62, and wall 64 is perpendicular to walls 63 and 65. Therefore, wall 63 is parallel to wall 65 and faces wall 65. The corridor 66 extends along wall 63 at the lower end of wall 63. The mirror 50 is installed on wall 63. An entrance 67 (opening) is provided on wall 65. A door (not shown) may be installed at the entrance 67 so as to be openable and closable. The subject P (see Figures 4-6) enters the room 100 from the entrance 67, moves to another room through the corridor 66, or exits the room through the entrance 67 from the corridor 66. The control device 10, projector 20, and detection device 30 of the projection system 1 are mounted on the ceiling 61. However, this is not limited to the control device 10, projector 20, and detection device 30, and at least a part of them may be mounted on the floor 62 or walls 63-65, or placed on a pedestal or the like (not shown). Also, the room 100 is not limited to a part of a house, but may be part of various facilities such as a commercial facility or a public facility. The subject P has a direct or indirect visual function, and in this embodiment, the subject P is a person. A person is one form of "subject". Hereafter in this specification, unless otherwise specified, the subject P will be described as a person P. For example, object P may be a drone that allows a person to see the target via video captured by a camera, and object P may include at least a person. For example, object P may consist of a person and a vehicle that the person is riding in (car, bicycle, wheelchair, etc.).

[0013] The projector 20 projects (forms) an image onto the floor surface 62 or wall surfaces 63-65 by irradiating the floor surface 62 or wall surfaces 63-65 with highly directional projection light having an intensity distribution corresponding to the image data 232 (see Figure 3). The area on which the image is projected among the floor surface 62 and wall surfaces 63-65 will be referred to as the projection surface below. In this embodiment, the projection surfaces are set as a first projection surface S1 on wall surface 65, a second projection surface S2a on floor surface 62, and a second projection surface S2b on wall surface 64. In this embodiment, each of these projection surfaces is rectangular. Of these, the first projection surface S1 is the area on which the first image 41 (see Figure 4) seen by a person P located in the first range R1 through the mirror 50, and the second image 42 (see Figure 5) seen directly by a person P located in the second range R2 are projected, as will be described in detail later. In the following, the presence of person P within a certain range will simply be described as "person P is within a certain range." The second projection planes S2a and S2b are the regions onto which the third image 43 (see Figure 6), which is directly visible to person P when they are located within the first range R1 and the second range R2, is projected. The second projection plane S2a is assumed to be located between the first range R1 and the second range R2 on the floor surface 62. In the following, when referring to either the second projection plane S2a or S2b, it will be described as "second projection plane S2." By projecting an image onto either the first projection surface S1 or the second projection surfaces S2a, S2b using the projector 20, a comfortable presentation can be provided while using the light emitted by the projector 20 as illumination. The projector 20 is mounted on the ceiling 61 in a manner that allows the projection direction to be adjusted so that an image can be projected onto the first projection surface S1 or the second projection surfaces S2a, S2b.

[0014] Figure 2 shows the mechanism of the projector 20 for mounting to the ceiling 61 and for adjusting the projection direction. The projector 20 is mounted on the ceiling 61 via a projection direction adjustment device 70. The projection direction adjustment device 70 includes a holding member 73 for holding the projector 20, a first adjustment unit 71 for mounting the holding member 73 to the ceiling 61 so that it can rotate around a first axis A1 perpendicular to the ceiling 61, and a second adjustment unit 72 for mounting the projector 20 to the holding member 73 so that it can rotate around a second axis A2 perpendicular to the first axis A1.

[0015] The first adjustment unit 71 includes a first fixed part 71a fixed to the ceiling 61 and a first rotating part 71b that can rotate around the first axis A1 relative to the first fixed part 71a by the operation of a motor (not shown). The retaining member 73 has a plate-shaped base 731 that is substantially parallel to the ceiling 61 and fixed to the first rotating part 71b of the first adjustment part 71, and plate-shaped side plates 732 that extend from both ends of the base 731 and are substantially perpendicular to the base 731. The base 731 is fixed to the first rotating part 71b by passing a fixing member (not shown) through a mounting hole 731a provided in its center. The second adjustment unit 72 is attached to at least one of the two sides of the housing 20a of the projector 20 with respect to the surface on which the projection lens 20b from which the projected light is emitted is provided. The second adjustment unit 72 has a second rotating part 72a and a second fixed part 72b. The second fixed part 72b is fixed to the side plate 732 of the holding member 73 by a fixing member (not shown) that passes through a mounting hole 732a of the side plate 732 of the holding member 73. The second rotating part 72a is fixed to the side of the housing 20a of the projector 20 and rotates around the second axis A2 relative to the second fixed part 72b by the operation of a motor (not shown).

[0016] With the projector 20 mounted to the ceiling 61 via the holding member 73, the projector 20 can be rotated around the first axis A1 together with the holding member 73 by rotating the first rotating part 71b of the first adjustment part 71 relative to the first fixing part 71a. This allows the projection direction of the image by the projector 20 to be adjusted in terms of rotational direction around the first axis A1. Furthermore, by rotating the second rotating part 72a of the second adjustment part 72 relative to the second fixed part 72b, the projector 20 can be rotated around the second axis A2. This allows the projection direction of the image by the projector 20 to be adjusted in terms of the rotation direction around the second axis A2. By combining rotation around the first axis A1 and rotation around the second axis A2, images can be projected in any direction as long as they are within the rotational range of each axis. Note that Figure 2 is an example of a mechanism for adjusting the projection direction of the image from the projector 20 (the orientation of the projector 20), and the projection direction of the image from the projector 20 may be adjusted by other mechanisms.

[0017] The detection device 30 shown in Figure 1 detects a person P in room 100 and transmits data related to the detection result to the control device 10. The detection device 30 has a first sensor 31 that detects person P when they are in a first range R1, and a second sensor 32 that detects person P when they are in a second range R2. The first sensor 31 is located on the opposite side of the projector 20 from the second sensor 32. In other words, the first range R1 is an area where person P can be detected by the first sensor 31 but not by the second sensor 32, and the second range R2 is an area where person P can be detected by the second sensor 32 but not by the first sensor 31. For example, pyroelectric infrared sensors that detect infrared radiation emitted by person P using the pyroelectric effect of pyroelectric ceramics can be used as the first sensor 31 and the second sensor 32. However, the detection methods of the first sensor 31 and the second sensor 32 are not particularly limited as long as they are capable of detecting a person (object) P. For example, the first sensor 31 and the second sensor 32 may be object detection sensors using CMOS (Complementary Metal Oxide Semiconductor) area sensors.

[0018] In this embodiment, the first range R1 is a substantially circular (or substantially elliptical) area near the entrance 67. The orientation and sensitivity of the first sensor 31 are adjusted to detect a person P when the person P is in a substantially conical (or substantially elliptical conical) space connecting the substantially circular (or substantially elliptical) first range R1 and the first sensor 31. Furthermore, in this embodiment, the second range R2 is a roughly circular (or roughly elliptical) area in the vicinity of the corridor 66. The orientation and sensitivity of the second sensor 32 are adjusted to detect a person P when the person P is in a roughly conical (or roughly elliptical cone) space connecting the roughly circular (or roughly elliptical) second range R2 and the second sensor 32. Furthermore, in this embodiment, the first range R1 is the region on the opposite side of the mirror 50 from the projector 20 (i.e., the region on the first projection surface S1 side), and the second range R2 is the region on the opposite side of the projector 20 from the first projection surface S1. Note that the first range R1 and the second range R2 shown in Figure 1 are illustrative examples, and the shape and size of the first range R1 and the second range R2 can be changed as appropriate.

[0019] The control device 10 determines whether person P is in the first range R1 and whether person P is in the second range R2, based on the detection result of person P by the detection device 30. Based on this determination, the control device 10 also determines which projection surface from the first projection surface S1, second projection surfaces S2a and S2b will be used to project the image, and the projection mode of the image (whether or not the image is horizontally flipped, and the content of geometric correction (trapezoidal correction) of the image shape, etc.). The control device 10 also controls the operation of the projector 20 by transmitting a projection control signal to the projector 20. Specifically, it transmits a projection control signal to the projector 20 to project the image onto the projection surface determined as described above, with the determined projection mode. Upon receiving the projection control signal, the projector 20 performs image processing on the image data 232 to achieve the projection mode determined by the control device 10. The projector 20 also controls the projection direction adjustment device 70 to change its orientation so that the image is projected onto the projection surface determined by the control device 10, and projects the image based on the corrected image data 232. The control of the projector 20 by the control device 10 will be described in detail later.

[0020] <Projection System Configuration> Figure 3 is a block diagram showing the functional configuration of the control device 10, projector 20, and detection device 30. The control device 10 includes a CPU 11 (Central Processing Unit), RAM (Random Access Memory) 12, a storage unit 13, a communication unit 14, and the other components, and these components are connected by a bus 15.

[0021] The CPU 11 is a processor that controls the operation of each part of the control device 10 by reading and executing the program 131 stored in the memory unit 13 and performing various arithmetic operations. In this embodiment, the CPU 11 corresponds to the "processing unit" and the "computer". The processing unit may have multiple processors (for example, multiple CPUs), and multiple processors may execute multiple processes that the CPU 11 would normally execute. In this case, multiple processors correspond to the "processing unit". In this case, multiple processors may be involved in common processing, or multiple processors may independently execute different processes in parallel.

[0022] RAM12 provides CPU11 with a working memory space and stores temporary data.

[0023] The storage unit 13 is a non-temporary recording medium readable by the CPU 11, which functions as a computer, and stores the program 131 and various data. The storage unit 13 includes non-volatile memory such as flash memory. The program 131 is stored in the storage unit 13 in the form of program code that can be read by the computer.

[0024] The communication unit 14 performs communication operations in accordance with predetermined communication standards. Through these communication operations, the communication unit 14 transmits and receives data wirelessly or via wired connection between the projector 20 and the detection device 30. The communication unit 14 may also be capable of transmitting and receiving data with external devices other than the projector 20 and the detection device 30.

[0025] The projector 20 includes a CPU 21, RAM 22, memory unit 23, projection unit 24, communication unit 25, etc., and these units are connected by a bus 26.

[0026] The CPU 21 is a processor that controls the operation of each part of the projector 20 by reading and executing the program 231 stored in the memory unit 23 and performing various arithmetic operations. The projector 20 may have multiple processors (for example, multiple CPUs), and multiple processors may perform the same multiple processes that the CPU 21 would normally perform. In this case, multiple processors may be involved in common processes, or multiple processors may independently execute different processes in parallel.

[0027] RAM22 provides CPU21 with a working memory space and stores temporary data.

[0028] The memory unit 23 is a non-temporary recording medium readable by the CPU 21, which functions as a computer, and stores the program 231 and various data. The memory unit 23 includes non-volatile memory such as flash memory. The program 231 is stored in the memory unit 23 in the form of program code that can be read by the computer. The data stored in the memory unit 23 includes image data 232 used for projection.

[0029] The projection unit 24 includes a light source unit 241, a display element 242, and an optical system drive unit 243, etc. The projection unit 24 adjusts the intensity distribution of light output from the light source unit 241 using the display element 242 according to the image data 232, and projects an image by emitting the light to the outside of the projector 20 through a group of projection lenses (not shown).

[0030] The light source unit 241 emits light in the blue wavelength band (blue light), light in the green wavelength band (green light), and light in the red wavelength band (red light). In this embodiment, the light source unit 241 outputs blue light generated by a laser diode, red light generated by an LED, and green fluorescence (green light) generated by incidenting the above-mentioned blue light onto a predetermined phosphor. However, the method of generating each color of light in the light source unit 241 is not limited to the above. In this embodiment, the light source unit 241 outputs red light, green light, and blue light in separate periods.

[0031] The display element 242 is a spatial optical modulator (SOM), such as a digital micromirror element (DMD). The DMD rapidly switches the tilt angle of each of the multiple minute mirrors arranged in an array according to the pixel value of the image data 232, determining whether or not light is reflected to the projection lens group for each pixel and each image frame, thereby forming an optical image with the reflected light. As described above, red light, green light, and blue light are incident on the display element 242 from the light source 241 in a time-division manner, and the display element 242 generates a red image, a green image, and a blue image, respectively, during the period of incidence of red light, green light, and blue light. The projector 20 projects a color image using a field sequential method, which rapidly repeats the projection of these red, green, and blue images.

[0032] The projection lens group, into which the light reflected by the display element 242 (the light that forms the image) enters, is a zoom lens that allows adjustment of the magnification (zoom ratio, focal length) of the output image by changing the relative positions of the multiple lenses. The optical system drive unit 243 moves the multiple lenses constituting the projection lens group in accordance with the control signals transmitted from the CPU 11 to adjust the zoom ratio and focus of the projection lens group. The optical system drive unit 243 is equipped with actuators that move each of the multiple lenses in the optical axis direction. The optical system drive unit 243 operates according to the control signals transmitted from the CPU 21.

[0033] The communication unit 25 performs communication operations in accordance with predetermined communication standards. Through these communication operations, the communication unit 25 transmits and receives data wirelessly or via wired connection with the control device 10.

[0034] As described above, the projection direction adjustment device 70 includes a first adjustment unit 71 and a second adjustment unit 72. The projection direction adjustment device 70 includes a communication unit that communicates with the projector 20, and a control unit that operates the motors of the first adjustment unit 71 and the second adjustment unit 72 according to control signals received from the projector 20. By operating the motors of the first adjustment unit 71 and the second adjustment unit 72, the orientation of the projector 20 rotates independently around the first axis A1 and the second axis A2 shown in Figure 2.

[0035] As described above, the detection device 30 includes a first sensor 31 and a second sensor 32. The first sensor 31 and the second sensor 32 each include a communication unit that communicates with the control device 10, a detection element having pyroelectric ceramics that generates a voltage signal in response to temperature changes caused by infrared radiation, and a control unit such as a microcontroller that generates detection data related to the detection result of a person P in response to the voltage signal from the detection element and transmits it to the control device 10.

[0036] <Projection system operation> Next, the operation of projection system 1 will be described. The projection system 1 determines the projection surface and projection mode of the image according to the position of person P in room 100, and then projects the image. More specifically, the CPU 11 of the control device 10 determines, based on the detection result of person P by the detection device 30, whether person P is in a first range R1 where the first projection surface S1 reflected in the mirror 50 is visible, and whether person P is in a second range R2 where the first projection surface S1 is directly visible. Here, for a person P in the first range R1 or the second range R2 to be able to see the image means that the person P in each range can see the entire image in their normal posture within that range. For example, the normal posture of person P in the first range R1 is to have their gaze directed towards the walls 63, 64, or the floor 62. Therefore, a person P in the normal posture in the first range R1 can see the first projection surface S1 reflected in the mirror 50 on the wall 63, but cannot see the first projection surface S1 directly. This is because, from the first range R1, the first projection surface S1 cannot be seen unless the person adopts an unusual posture, such as looking up at the wall 65 directly above them. Also, the normal posture of person P in the second range R2 is to have their gaze directed towards the walls 63-65 or the floor 62. Therefore, a person P in the normal posture in the second range R2 can directly see the first projection surface S1 on the wall 65. On the other hand, when a person P in a normal posture within the second range R2 looks at the mirror 50 on the wall surface 63, their reflection will be large, and therefore, the person P will not be able to see the entire first projection surface S1 reflected in the mirror 50. The mirror 50 may also be positioned so that a person P in a normal posture within the second range R2 cannot see the first projection surface S1 through the mirror 50. If the CPU 11 determines that person P is in the first range R1, it sends a projection control signal to the projector 20, causing the projector 20 to project a first image 41, which is recognized as being in the normal orientation when reflected in the mirror 50, onto the first projection surface S1. If the CPU 11 determines that person P is in the second range R2, it sends a projection control signal to the projector 20, causing the projector 20 to project a second image 42, which is recognized as being in the normal orientation when directly viewed, onto the first projection surface S1.

[0037] Figure 4 illustrates the projection behavior of the first image 41 when person P is in the first range R1. If person P is in the first range R1, the first sensor 31 of the detection device 30 detects person P, while the second sensor 32 does not detect person P. Based on this detection result by the detection device 30, the CPU 11 of the control device 10 can determine that person P is in the first range R1.

[0038] The first projection surface S1 is located above the entrance 67 on the wall surface 65, and therefore cannot be directly seen by a person P in a normal posture within the first range R1. However, a person P within the first range R1 can see the first projection surface S1 reflected in the mirror 50 (in other words, can see the first projection surface S1 through the mirror 50). For this reason, when it is determined that a person P is within the first range R1, the CPU 11 of the control device 10 adjusts the orientation of the projector 20 so that the projection lens 20b of the projector 20 faces the first projection surface S1, and then the projector 20 projects the first image 41 onto the first projection surface S1. As described above, the orientation of the projector 20 is adjusted by the CPU 21 of the projector 20, which has received a projection control signal from the control device 10, controlling the projection direction adjustment device 70 according to the projection control signal. However, this is not limited to this, and the control device 10 may directly control the projection direction adjustment device 70. Here, the first image 41 is an image that is recognized as being in the normal orientation when reflected in the mirror 50, and is an image that has been horizontally flipped from the normal orientation image (an image that is recognized as being in the normal orientation when viewed directly). In the example shown in Figure 4, the first image 41, which includes the horizontally flipped word "Welcome", is projected onto the first projection surface S1. Person P views the mirror image 41r of this first image 41 reflected in the mirror 50. In the mirror image 41r, the word "Welcome" is recognized as being in the normal orientation. Note that the mirror image 41r of the first image 41 is actually viewed as being in a position symmetrical to the surface of the mirror 50, but in Figure 4, for convenience, the mirror image 41r is drawn at the position of the mirror 50 (the same applies to the mirror image 41r in Figure 10, which will be described later).

[0039] Furthermore, the CPU 11 of the control device 10 causes the projector 20 to project the first image 41, whose shape has been corrected so that it is recognized as a normal shape when reflected in the mirror 50, onto the first projection surface S1. For example, if the direction of the projection light from the projector 20 is deviated from perpendicular to the wall surface 65, and the first image 41 projected as a rectangle becomes a shape different from a rectangle (e.g., a trapezoid) on the first projection surface S1, the CPU 11 of the control device 10 performs geometric correction on the image data 232 so that the first image 41 becomes a rectangle on the first projection surface S1 before projection. That is, the CPU 11 of the control device 10 transmits a projection control signal including geometric correction parameters to the projector 20, and the CPU 21 of the projector 20 performs geometric correction on the image data 232 based on the parameters of the received projection control signal before projecting the first image 41. Here, the geometric correction process is a process of thinning out a part of the image data 232 so that the image becomes a desired shape (e.g., a rectangle) on the projection surface, and includes so-called trapezoidal correction. The parameters for geometric correction may be pre-set based on the positional relationship between the projector 20 and the wall 65, or the CPU 11 may derive them each time based on the results of determining the angle between the orientation of the projector 20 and the wall 65 during projection using a sensor such as a camera. If the first image 41 is rectangular on the first projection surface S1, then person P will normally perceive the mirror image 41r, which is the first image 41 reflected in the mirror 50, as having a normal shape. Furthermore, the shape of the first image 41 on the first projection plane S1 may be corrected so that the mirrored image 41r, obtained by reflecting the first image 41 in the mirror 50, is rectangular as seen by person P. In this case, the first image 41 does not necessarily have to be rectangular on the first projection plane S1.

[0040] Figure 5 illustrates the projection behavior of the second image 42 when person P is in the second range R2. If person P is in the second image 42, the first sensor 31 of the detection device 30 does not detect person P, but the second sensor 32 does. Based on this detection result by the detection device 30, the CPU 11 of the control device 10 can determine that person P is in the second range R2.

[0041] Person P in the second range R2 can directly see the first projection surface S1 located above the entrance 67 on the wall surface 65. Therefore, when the CPU 11 of the control device 10 determines that person P is in the second range R2, the projection lens 20b of the projector 20 is pointed towards the first projection surface S1, and the projector 20 projects the second image 42 onto the first projection surface S1. Here, the second image 42 is a normal orientation image (an image that is not flipped horizontally) that is recognized as the normal orientation when directly viewed. In the example shown in Figure 5, the second image 42 containing the words "Thank you" is projected onto the first projection surface S1. As can be seen by comparing Figures 4 and 5, the orientation of the projector 20 does not change when projecting the first image 41 onto the first projection surface S1 when person P is in the first range R1, and when projecting the second image 42 onto the first projection surface S1 when person P is in the second range R2. Only the projection mode of the image (whether or not it is horizontally flipped) is switched. Therefore, even if the position of person P changes to the opposite side of the projector 20, the state of the projector 20 can be switched more easily according to the position of person P.

[0042] When projecting the second image 42, the CPU 11 of the control device 10 causes the projector 20 to perform geometric correction on the image data 232 so that the second image 42 becomes rectangular on the first projection surface S1, and then projects the second image 42. The parameters for geometric correction may be set in advance based on the positional relationship between the projector 20 and the wall surface 65, or the CPU 11 may derive the parameters each time based on the results of determining the orientation of the projector 20 at the time of projection and the angle it makes with the wall surface 65 using a sensor such as a camera.

[0043] Next, we will explain the projection behavior when person P is present in both the first range R1 and the second range R2. When the CPU 11 of the control device 10 determines that there is a person in the first range R1, and also determines that there is a person in the second range R2, it causes the projector 20 to project a third image 43, which is recognized as being in the normal orientation when directly viewed, onto either the second projection surface S2a or S2b, which is directly visible to the person P in the first range R1 and the person P in the second range R2.

[0044] Figure 6 illustrates the projection behavior of the third image 43 when person P is in the first range R1 and the second range R2. If person P is in the first range R1 and the second image 42, the first sensor 31 and the second sensor 32 of the detection device 30 detect person P. Based on this detection result by the detection device 30, the CPU 11 of the control device 10 can determine that person P is in the first range R1 and the second range R2.

[0045] Person P in the first range R1 and person P in the second image 42 can both directly see the second projection surface S2a on the floor 62 and the second projection surface S2b on the wall 64. Therefore, when the CPU 11 of the control device 10 determines that person P is in the first range R1 and the second range R2, it adjusts the orientation of the projector 20 so that the projection lens 20b of the projector 20 faces either the second projection surface S2a or S2b, and then projects the third image 43 onto one of the second projection surfaces S2a or S2b using the projector 20. Here, the third image 43, like the second image 42, is an image in a normal orientation that is recognized as normal when directly viewed. In the example shown in Figure 6, the third image 43, which includes the words "Good Day", is projected onto the second projection surface S2a. When projecting the third image 43 onto the second projection surface S2a of the floor surface 62, the third image 43 may be rotated before projection so that it does not appear upside down to either person P in the first range R1 or person P in the second range R2 (i.e., the two side edges of the third image 43 are located on the side of person P in the first range R1 and person P in the second range R2, respectively).

[0046] When projecting the third image 43, the CPU 11 of the control device 10 causes the projector 20 to perform geometric correction on the image data 232 so that the third image 43 becomes rectangular on the third projection surfaces S2a and S2b, and then projects the third image 43.

[0047] When the first image 41, the second image 42, or the third image 43 is projected, the focus is adjusted by the operation of the optical system drive unit 243 according to the distance from the projection lens 20b to the first projection surface S1, the second projection surfaces S2a, and S2b. In addition, the zoom magnification may be adjusted (zoom in or zoom out) by the operation of the optical system drive unit 243 so that the projected image is of a predetermined size according to the above distance. The adjustments for focus and zoom magnification may be instructed from the control device 10 to the projector 20 by a projection control signal, or the CPU 21 of the projector 20 may be determined according to the projection surface instructed by the projection control signal. Furthermore, the adjustment amounts for focus and zoom magnification may be derived in advance for each projection surface, or the distance between the projector 20 and the projection surface may be determined using a sensor such as a camera, and the adjustments may be derived each time based on the result of that determination.

[0048] <Projection control processing and image projection processing> Next, we will describe the projection control process performed by the CPU 11 of the control device 10 to control the image projection operation by the projector 20, and the image projection process performed by the CPU 21 of the projector 20 to project the image.

[0049] Figure 7 is a flowchart illustrating the control procedure for the projection control process. The projection control process is initiated, for example, when the projection system 1 is started up and a user operation is performed on the control device 10 or projector 20 to authorize the projection of an image.

[0050] When projection control processing is started, the CPU 11 of the control device 10 determines whether the first sensor 31 has detected a person P (step S101) and whether the second sensor 32 has detected a person P (step S102 or step S113) based on the data related to the detection result of a person P received from the detection device 30. If it is determined that neither the first sensor 31 nor the second sensor 32 has detected a person P (NO in step S101 and NO in step S113), the CPU 11 returns to step S101.

[0051] If the first sensor 31 and the second sensor 32 determine that a person P has been detected ("YES" in step S101 and "YES" in step S102), the CPU 11 determines that a person P is in the first range R1 and the second range R2, and determines one second projection surface S2 that can be directly seen from the first range R1 and the second range R2 as the projection target (step S103). The method for determining one second projection surface S2 from a plurality of second projection surfaces S2 is not particularly limited, but for example, one may be selected in advance by the user, or one may be selected first, and then another second projection surface S2 may be selected if an obstacle is detected in the path of the projection light onto that second projection surface S2 by a sensor (not shown).

[0052] The CPU 11 determines the orientation of the projector 20 so that an image can be projected onto the determined second projection surface S2 (step S104). The orientation of the projector 20 corresponding to each second projection surface S2 is derived in advance and stored in the storage unit 13.

[0053] The CPU 11 determines the content and orientation of the third image 43 to be suitable for viewing from the first range R1 and the second range R2 (step S105). Here, the content of the image is determined, for example, by selecting one of several pre-prepared image data 232 (the same applies to the determination of the image content in steps S109 and S116 described later). Furthermore, if the third image 43 is upside down when projected with the orientation of the projector 20 determined in step S104, the CPU 11 decides to perform a rotation process to rotate the image data 232 of the third image 43 by 90° so that the orientation of the third image 43 is rotated by 90°. Note that in step S104, the orientation of the projector 20 may be determined in such a way that this rotation process is unnecessary.

[0054] The CPU 11 determines the content of the geometric correction applied to the image data 232 of the third image 43 so that the third image 43 becomes a rectangle on the second projection plane S2 (step S106).

[0055] The CPU 11 generates a projection control signal for projecting the third image 43, including the decisions made in steps S103 to S106, and sends it to the projector 20 (step S107).

[0056] On the other hand, if the first sensor 31 detects a person P and the second sensor 32 determines that it has not detected a person P ("YES" in step S101 and "NO" in step S102), the CPU 11 determines that a person P is in the first range R1 of the two ranges R2 and determines the orientation of the projector 20 so that an image can be projected onto the first projection surface S1 (step S108). The orientation of the projector 20 corresponding to the first projection surface S1 is derived in advance and stored in the storage unit 13. The CPU 11 also determines the content of the image that is suitable to be viewed from the first range R1 (step S109).

[0057] The CPU 11 decides to perform a horizontal flip operation on the image data 232 of the image determined in step S109 so that it is recognized as having the correct orientation when reflected in the mirror 50 (step S110). The image obtained by horizontally flipping the image determined in step S109 corresponds to the first image 41.

[0058] The CPU 11 determines the content of the geometric correction applied to the image data 232 of the first image 41 so that when the first image 41 is reflected in the mirror 50, it is recognized as having a normal shape (for example, so that the first image 41 is rectangular on the first projection surface S1, or so that the mirrored image 41r of the first image 41 reflected in the mirror 50 is rectangular as seen by person P) (step S111).

[0059] The CPU 11 generates a projection control signal for projecting the first image 41, including the decisions made in steps S108 to S111, and sends it to the projector 20 (step S112).

[0060] On the other hand, if the first sensor 31 does not detect person P, and the second sensor 32 determines that person P has been detected ("NO" in step S101 and "YES" in step S113), the CPU 11 determines that person P is in the second range R2 of the two ranges R2, and determines the first projection surface S1, which can be directly seen from the second range R2, to be the projection target (step S114).

[0061] The CPU 11 determines the orientation of the projector 20 so that an image can be projected onto the first projection surface S1 (step S115). The orientation of the projector 20 corresponding to the first projection surface S1 is derived in advance and stored in the storage unit 13.

[0062] The CPU 11 determines the content of the second image 42 that is suitable to view from the second range R2 (step S116).

[0063] The CPU 11 determines the content of the geometric correction applied to the image data 232 of the second image 42 so that the second image 42 becomes a rectangle on the second projection plane S2 (step S117).

[0064] The CPU 11 generates a projection control signal for projecting the second image 42, including the decisions made in steps S114 to S117, and sends it to the projector 20 (step S118). When a projection control signal is sent to the projector 20 in step S107, S112, or S118, the CPU 11 terminates the projection control process.

[0065] Figure 8 is a flowchart illustrating the control procedure for image projection processing. Image projection processing is initiated, for example, when the projection control processing described above is started. When the image projection process starts, the CPU 21 of the projector 20 determines whether or not it has received a projection control signal from the control device 10 (step S201). If it determines that it has not received a projection control signal ("NO" in step S201), it executes step S201 again.

[0066] If it is determined that a projection control signal has been received ("YES" in step S201), the CPU 21 sends a control signal to the projection direction adjustment device 70 to operate the projection direction adjustment device 70 and adjust the orientation of the projector 20 to the orientation indicated in the projection control signal (step S202). If the projector 20 is already projecting an image (emitting projection light) at the start of step S202, the amount of projection light may be reduced or the emission of projection light may be temporarily stopped until the orientation of the projector 20 is adjusted. This makes it possible to suppress the occurrence of the problem where the projection light is directed at person P and causes glare when the orientation of the projector 20 is changed.

[0067] The CPU 21 acquires image data 232 of the image specified in the projection control signal (step S203). Here, the CPU 21 may acquire image data 232 of the specified image from image data pre-stored in the storage unit 23, or, if the image data 232 is not stored in the storage unit 23, it may acquire the image data 232 from an external device via the communication unit 25.

[0068] The CPU 21 determines whether the projection control signal includes an instruction to perform a horizontal inversion process on the image data 232 (step S204). If it is determined that an instruction to perform a horizontal inversion process is included ("YES" in step S204), the CPU 21 performs a horizontal inversion process on the image data 232 acquired in step S203 (step S205).

[0069] If step S205 is completed, or if it is determined in step S204 that there is no instruction to perform a left-right flip process ("NO" in step S204), the CPU 21 determines whether the projection control signal contains an instruction to perform a rotation process on the image data 232 (step S206). If it is determined that there is an instruction to perform a rotation process ("YES" in step S206), the CPU 21 performs a rotation process of the specified angle on the image data 232 acquired in step S203 (step S207).

[0070] If step S207 is completed, or if it is determined in step S206 that the instruction to perform rotation processing is not included ("NO" in step S206), the CPU 21 determines whether the projection control signal includes an instruction to perform geometric correction processing on the image data 232 (step S208). If it is determined that an instruction to perform geometric correction processing is included ("YES" in step S208), the CPU 21 performs the specified geometric correction processing on the image data 232 acquired in step S203 (step S209).

[0071] If step S209 is completed, or if it is determined in step S208 that there is no instruction to perform geometric correction processing ("NO" in step S208), the CPU 21 operates the projection unit 24 based on the image data 232 to project the image (step S210). When step S210 is completed, the CPU 21 terminates the image projection process.

[0072] <Variation> In the above embodiment, when there are people P in the first range R1 and the second range R2, the third image 43 is projected onto either the second projection surface S2a or S2b. However, instead, the amount of adjustment required for the orientation of the projector 20 may be reduced by projecting the first image 41 or the second image 42 onto the first projection surface S1. In this case, the number of people P located in the first range R1 and the number of people P located in the second range R2 are counted. If the number of people P located in the first range R1 is greater than the number of people P located in the second range R2, the projector 20 may project the first image 41 onto the first projection surface S1. If the number of people P located in the second range R2 is greater than the number of people P located in the first range R1, the projector 20 may project the second image 42 onto the first projection surface S1. If the number of people P located in the first range R1 is equal to the number of people P located in the second range R2, then either the first image 41 may be projected onto the first projection plane S1, or the second image 42 may be projected onto the first projection plane S1.

[0073] Figure 9 is a flowchart illustrating the control procedure for the projection control process related to the modified example. The projection control process in Figure 9 is equivalent to a modified version of the projection control process in Figure 7. Below, we will explain the differences between this process and the flowchart of the projection control process in Figure 7, omitting explanations of common points. In the projection control process shown in Figure 9, if the first sensor 31 and the second sensor 32 determine that they have detected a person P (YES in step S101 and YES in step S102), the CPU 11 determines whether the number of people P in the first range R1 is greater than the number of people P in the second range R2 (step S119). If it is determined that the number of people P in the first range R1 is greater than the number of people P in the second range R2 (YES in step S119), the CPU 11 proceeds to step S108 in Figure 7 and executes steps S108 to S112 to project the first image 41 onto the first projection surface S1. If it is determined that the number of people P in the second range R2 is equal to or greater than the number of people P in the first range R1 ("NO" in step S119), the CPU 11 moves the process to step S114 in Figure 7, and executes steps S114 to S118 to project the second image 42 onto the first projection plane S1. Note that in Figure 9, the process moves to step S114 when the number of people P in the first range R1 and the number of people P in the second range R2 are the same, but instead, the process may move to step S108.

[0074] <Effects> As described above, the projection system 1 according to the first embodiment includes a CPU 11 (processing unit), which, based on the detection result of person P by the detection device 30, determines whether person P is in a first range R1 where the first projection surface S1 reflected in the mirror 50 is visible, and whether person P is in a second range R2 where the second projection surface S2 is directly visible. If it is determined that person P is in the first range R1, the projector 20 projects a first image 41, which is recognized as being in the normal orientation when reflected in the mirror 50, onto the first projection surface S1. If it is determined that person P is in the second range R2, the projector 20 projects a second image 42, which is recognized as being in the normal orientation when directly viewed, onto the first projection surface S1. In this way, by making the first projection surface S1 visible through the mirror 50 selectable as the projection target for the first image 41, the amount of adjustment required for the orientation of the projector 20 according to the position of person P can be reduced. For example, when the situation changes from one person P being in the first range R1 to one person P being in the second range R2, the projector 20 can be rotated to project an image visible to each person P simply by switching the projection mode (whether or not it is horizontally flipped), without adjusting the orientation of the projector 20. Therefore, switching the state of the projector 20 according to the position of person P can be done more easily.

[0075] Furthermore, the detection device 30 includes a first sensor 31 that detects person P when they are in the first range R1, and a second sensor 32 that detects person P when they are in the second range R2. This allows for accurate detection of whether or not person P is in the first range R1 and the second range R2 with a simple configuration.

[0076] Furthermore, the CPU 11 projects the first image 41, whose shape has been corrected so that it is recognized as a normal shape when reflected in the mirror 50, onto the first projection surface S1 using the projector 20. When a person P views the first image 41 reflected in the mirror 50, the path of the projected light emitted from the projector 20 to reach person P becomes complex and long, making it easy for the shape of the mirrored image 41r of the first image 41 to be viewed in a distorted state. However, by correcting the shape of the first image 41 as described above, the viewed mirrored image 41r can be made to have a more natural shape.

[0077] Furthermore, if the CPU 11 determines that person P is in the first range R1 and also determines that person P is in the second range R2, the CPU 11 causes the projector 20 to project a third image 43, which is recognized as being in the normal orientation when directly viewed, onto the second projection surface S2, which is directly visible to person P in the first range R1 and person P in the second range R2. This allows the projection of a third image 43 that is visible to person P in the first range R1 and person P in the second range R2.

[0078] Furthermore, in the modified version, if the CPU 11 determines that there is a person P in the first range R1, and also determines that there is a person P in the second range R2, it counts the number of people P in the first range R1 and the number of people P in the second range R2. If the number of people P in the first range R1 is greater than the number of people P in the second range R2, the projector 20 projects the first image 41 onto the first projection surface S1. If the number of people P in the second range R2 is greater than the number of people P in the first range R1, the projector 20 projects the second image 42 onto the first projection surface S1. This makes it possible to allow more people P to view the image while keeping the amount of adjustment of the orientation of the projector 20 small.

[0079] Furthermore, the first projection surface S1 is positioned so that it cannot be directly seen by person P within the first range R1. This prevents person P from directly seeing the first image 41, which is reversed left to right before being reflected in the mirror 50.

[0080] Furthermore, the projection method executed by the CPU 11, which acts as the computer of the projection system 1 according to the first embodiment, determines, based on the detection result of the detection device 30, whether or not person P is in a first range R1 in which the first projection surface S1 reflected in the mirror 50 is visible, and whether or not person P is in a second range R2 in which the second projection surface S2 is directly visible. If it is determined that person P is in the first range R1, the projector 20 projects a first image 41, which is recognized as being in the normal orientation when reflected in the mirror 50, onto the first projection surface S1. If it is determined that person P is in the second range R2, the projector 20 projects a second image 42, which is recognized as being in the normal orientation when directly viewed, onto the first projection surface S1. This makes it easier to switch the state of the projector 20 according to the position of person P.

[0081] Furthermore, the program 131 according to the first embodiment causes the CPU 11, which acts as the computer of the projection system 1, to perform the following processes based on the detection result of person P by the detection device 30: determining whether person P is in a first range R1 where the first projection surface S1 reflected in the mirror 50 is visible, and whether person P is in a second range R2 where the second projection surface S2 is directly visible; if it is determined that person P is in the first range R1, causing the projector 20 to project a first image 41, which is recognized as being in the normal orientation when reflected in the mirror 50, onto the first projection surface S1; and if it is determined that person P is in the second range R2, causing the projector 20 to project a second image 42, which is recognized as being in the normal orientation when directly viewed, onto the first projection surface S1. This makes it easier to switch the state of the projector 20 according to the position of person P.

[0082] (Second embodiment) Next, a second embodiment will be described. In the following, components common to the first embodiment will be denoted by the same reference numerals and their descriptions will be omitted, while differences from the first embodiment will be described.

[0083] <Configuration and Operation of the Projection System> Figure 10 shows the configuration of the projection system 1 according to the second embodiment. As shown in Figure 10, the projection system 1 of the second embodiment is provided across a room 100 and a passage 200 adjacent to the room 100, separated by an entrance 67.

[0084] The detection device 30 of the second embodiment includes a first sensor 31 installed on the ceiling 69 of the passageway 200 and two second sensors 32a, 32b (multiple second sensors) installed on the ceiling 61 of the room 100. The first sensor 31 detects a person P when they are in a first range R1 in the passageway 200. The room 100 has two second ranges R2a, R2b (multiple second ranges), and the second sensor 32a detects a person P when they are in the second range R2a, and the second sensor 32b detects a person P when they are in the second range R2b. In other words, the first range R1 of this embodiment is a region in which the first sensor 31 can detect a person (target) P and the second sensors 32a and 32b cannot detect a person (target) P; the second range R2a is a region in which the second sensor 32a can detect a person P and the first sensor 31 and second sensor 32b cannot detect a person P; and the second range R2b is a region in which the second sensor 32b can detect a person P and the first sensor 31 and second sensor 32a cannot detect a person P. In this embodiment, the second range R2a is, for example, the same range as the first range R1 in the first embodiment, and the second sensor 32a is, for example, provided in the same position as the first sensor 31 in the first embodiment. Also, the second range R2b is, for example, the same range as the second range R2 in the first embodiment, and the second sensor 32b is, for example, provided in the same position as the second sensor 32 in the first embodiment. Note that in Figure 10 and Figure 11 described later, the description of the corridor 66 in the first embodiment is omitted. Also, in this embodiment, the second range R2a is the area on the opposite side of the first projection surface S1 with the projector 20 in between (i.e., the area on the entrance 67 side (the area on the mirror 50 side)), and the second range R2b is the area on the first projection surface S1 side with the projector 20 in between.

[0085] The mirror 50 is located near the entrance 67 in the passageway 200. The first projection surface S1 is set on the wall surface 63 of the room 100. The mirror 50 is positioned and angled so that a person P in the first range R1 of the passageway 200 can see the first projection surface S1 reflected in the mirror 50 through the opening of the entrance 67. A wall surface 68 extends between the first range R1 and the first projection surface S1, so the first projection surface S1 is not directly visible to the person P in the first range R1. In other words, in this embodiment, the first range R1 is the area on the mirror 50 side of the wall surface 68 (entrance 67) (i.e., the area opposite to the first projection surface S1 side), and the second ranges R2a and R2b are the areas on the opposite side of the mirror 50 of the wall surface 68 (entrance 67).

[0086] As shown in Figure 10, if a person P is in the first range R1, the first sensor 31 detects the person P. Based on this detection result, the CPU 11 of the control device 10 sends a projection control signal to the projector 20, causing the projector 20 to project a first image 41, which is recognized as being in the correct orientation when reflected in the mirror 50, onto the first projection surface S1 of the wall surface 63. As a result, person P sees the mirrored image 41r of the first image 41 reflected in the mirror 50. In the example shown in Figure 10, the shape of the first image 41 on the first projection surface S1 is geometrically corrected to a shape different from a rectangle so that the mirrored image 41r appears as a rectangle to person P.

[0087] Figure 11 shows room 100 in the second embodiment. In the second embodiment, as described above, the first projection surface S1 is set on the wall surface 63. On the other hand, since there is no projection surface that can be directly seen simultaneously by a person P in the first range R1 of the passageway 200 and a person P in the second range R2a or R2b of the room 100, the second projection surface is not set in this embodiment. In addition, in this embodiment, third projection surfaces S3a and S3b, which can be directly seen from the second range R2a and the second range R2b, are set on the floor surface 62 and the wall surface 64, respectively. For example, the third projection surface S3a is the same area as the second projection surface S2a in the first embodiment, and the third projection surface S3b is the same area as the second projection surface S2b in the first embodiment. Hereinafter, when referring to either the third projection surface S3a or S3b, it will be written as "third projection surface S3". A person P in the second range R2a can directly see the first projection surface S1, the third projection surfaces S3a and S3b. Furthermore, a person P in the second range R2b can directly see the first projection plane S1, the third projection planes S3b and S3c, and the fourth projection plane S4 set on the wall surface 65. The second range R2b can also be called the third range R3, from which the fourth projection plane S4 can be directly seen.

[0088] In this embodiment, when the CPU 11 of the control device 10 determines that person P is in the first range R1, it causes the projector 20 to project a first image 41 onto the first projection surface S1. This first image 41 is visible to person P through the mirror 50. If the CPU 11 of the control device 10 determines that there is no person P in the first range R1, it performs the following control depending on the presence or absence of person P in the second ranges R2a and R2b. Specifically, if the CPU 11 determines that person P is in the second range R2a and not in the second range R2b, or if it determines that person P is in both the second ranges R2a and R2b, it causes the projector 20 to project the second image 42 onto one of the first projection surface S1, third projection surface S3a, or S3b that is visible from the second ranges R2a and R2b. Furthermore, if the CPU 11 determines that person P is in the second range R2b (third range R3) and not in the second range R2a, it causes the projector 20 to project the second image 42 onto the fourth projection surface S4 that is visible only from the second projection surface R2b (third range R3).

[0089] Note that the number of second ranges R2 is not limited to two; three or more may be set. In this case, a second sensor 32 can be provided corresponding to each of the multiple second ranges R2. Furthermore, if it is determined that there are people in two or more different second ranges R2, the second image 42 should be projected onto a single projection surface (for example, one of the first projection surface S1, third projection surface S3a, or S3b) from which all detected people P can be seen.

[0090] <Projection control processing> Next, the projection control process of the second embodiment will be described. Note that the image projection process is the same as in the first embodiment, so its description will be omitted.

[0091] Figure 12 is a flowchart illustrating the control procedure for the projection control process in the second embodiment.

[0092] When projection control processing is started, the CPU 11 of the control device 10 determines whether or not the first sensor 31 has detected a person P based on the data related to the detection result of person P received from the detection device 30 (step S301).

[0093] If the first sensor 31 determines that a person P has been detected ("YES" in step S301), the CPU 11 determines the orientation of the projector 20 so that it can be projected onto the first projection surface S1 (step S302), determines the content of the image suitable for viewing from the first range R1 (step S303), decides to perform a left-right inversion process (step S304), determines the content of the geometric correction so that it is recognized as a normal shape when reflected in the mirror 50 (step S305), and generates a projection control signal to project the first image 41, including the decisions made in steps S302 to S305, and sends it to the projector 20 (step S306). The processing in steps S302 to S306 is the same as the processing in steps S108 to S112 in Figure 7.

[0094] If, in step S301, it is determined that the first sensor 31 has not detected person P ("NO" in step S301), the CPU 11 determines whether one or more second sensors 32 have detected person P (step S307). If it is determined that none of the second sensors 32 have detected person P ("NO" in step S307), the CPU 11 returns to step S301. If it is determined that one or more second sensors 32 have detected person P ("YES" in step S307), the CPU 11 determines whether only second sensor 32b has detected person P (step S308).

[0095] If it is determined that only the second sensor 32b has detected a person P ("YES" in step S308), the CPU 11 determines the fourth projection plane S4 as the projection target (step S309), determines the orientation of the projector 20 so that it can be projected onto the fourth projection plane S4 (step S310), determines the content and orientation of the second image 42 suitable for viewing from the second range R2 (step S311), determines the content of geometric correction (step S312), and generates a projection control signal for projecting the second image 42, including the decisions made in steps S309 to S312, and sends it to the projector 20 (step S313). The processing in steps S311 to S313 is the same as the processing in steps S116 to S118 in Figure 7.

[0096] On the other hand, if in step S308 it is determined that the second sensor 32b did not detect the person P ("NO" in step S308), the CPU 11 determines one of the first projection surface S1, the third projection surface S3a, or S3b as the projection target (step S314), determines the orientation of the projector 20 so that it can project onto the determined projection target (step S315), and proceeds to step S311. In the following step S313, a projection control signal is generated to project the second image 42, including the decisions made in steps S314, S315, S311, and S312, and sent to the projector 20 (step S313). When a projection control signal is sent to the projector 20 in step S306 or S313, the CPU 11 terminates the projection control process.

[0097] (others) The above-described embodiments are merely examples of the projection system, projection method, and program according to the present invention, and are not limited thereto. For example, the projector 20 may be configured to perform some of the functions that the control device 10 in the above embodiment performed. For instance, the CPU 21 of the projector 20 may determine the content of the geometric correction of the projected image according to the indicated projection surface. In this case, the CPU 11 of the control device 10 and the CPU 21 of the projector 20 correspond to the "processing units". Alternatively, the projector 20 may be configured to perform all the functions that the control device 10 in the above embodiment performed, and the control device 10 may be omitted. In this case, the CPU 21 of the projector 20 corresponds to the "processing unit". Alternatively, the detection device 30 may be included in the projector 20, and the detection device 30 may be omitted.

[0098] Furthermore, the detection device 30 may be equipped with a camera that photographs the interior of the room 100 instead of the first sensor 31 and the second sensor 32, and may detect the position of the person (or object) P based on the image captured by the camera. Alternatively, the CPU 11 of the control device 10, which receives the image captured by the camera of the detection device 30, may detect the position of the person (or object) P based on the image. In this case, the CPU 11 of the control device 10 and the detection device 30 constitute the "detection device".

[0099] Furthermore, although the above embodiment was described using an example in which the CPU 21 of the projector 20 performs image processing such as left-right inversion, rotation, and geometric correction of the image data related to the image to be projected, the embodiment is not limited to this. For example, the CPU 11 of the control device 10 may perform image processing of the image data, and the processed image data may be sent to the projector 20 for projection.

[0100] Furthermore, the positional relationship between the mirror 50, the first range R1, and the first projection surface S1 is not limited to that exemplified in the above embodiment. Any positional relationship is acceptable as long as a person P in the first range R1 can see the first projection surface S1 reflected in the mirror 50.

[0101] Furthermore, if the first range R1 is larger than a certain size, the position of person P within the first range R1 may be detected based on images of the first range R1 taken by the camera, and the position of the first projection surface S1 may be adjusted according to the relationship between the detected position of person P and the position of the mirror 50. For example, if a part of the first projection surface S1 reflected in the mirror 50 becomes invisible depending on the position of person P within the first range R1, the position of the first projection surface S1 may be adjusted so that the entire first projection surface S1 can be seen through the mirror 50. Alternatively, the position of the first projection surface S1 may be adjusted so that the first projection surface S1 is reflected in the center of the mirror 50 as seen from the perspective of person P at the detected position.

[0102] Furthermore, multiple first ranges R1 may be set for a single mirror 50, and multiple first projection surfaces S1 that are visible through the mirror 50 from each of these multiple first ranges R1 may be set. In this case, multiple first sensors 31 are provided to detect whether or not a person P is present in each of the multiple first ranges R1, and the first image 41 is projected onto the first projection surface S1 that is visible through the mirror 50 from the first range R1 in which person P is present. Furthermore, multiple mirrors 50 may be provided, and multiple first projection surfaces S1 that can be seen from one first range R1 through each mirror 50 may be set. In this case, when a person P is in the first range R1, the first image 41 should be projected onto one of the multiple first projection surfaces S1. Alternatively, multiple mirrors 50 may be provided, along with multiple first ranges R1 and multiple first sensors 31 corresponding to the multiple first ranges R1. In this case, for example, a first projection surface S1 corresponding to each combination of mirrors 50 and first ranges R1 may be set, and the first image 41 may be projected onto the first projection surface S1 corresponding to the first range R1 in which a person P is detected by the first sensor 31.

[0103] Furthermore, the projection system 1 may be equipped with a mirror detection device that detects the position and orientation of the mirror 50 by various known methods, and the CPU 11 may set a first projection surface S1 that can be seen by a person P in the first range R1 through the mirror 50 based on the detection result of the mirror 50 by the mirror detection device.

[0104] Furthermore, although the above embodiment was described using an example where the projection direction of the image is adjusted by rotating the projector 20 around the first axis A1 and the second axis A2 using the projection direction adjustment device 70, the method of adjusting the projection direction is not limited to this. For example, the projection system 1 may be provided with a mirror that reflects the light projected from the projector 20, and the projection direction of the image may be adjusted by changing the angle of this mirror.

[0105] Furthermore, although the above embodiment was described using an example where the projection system 1 is installed indoors, such as in a room 100 (or a room 100 and a passageway 200), the projection system 1 can be installed in any location with a projection surface, and for example, the projection system 1 may be installed outdoors.

[0106] Furthermore, while the above description discloses an example in which the flash memory of the storage unit 13 is used as a computer-readable medium for the program according to the present invention, the invention is not limited to this example. Other computer-readable mediums that can be used include information recording media such as HDDs, SSDs, and CD-ROMs. In addition, a carrier wave can also be used as a medium for providing the data of the program according to the present invention via a communication line.

[0107] Furthermore, it goes without saying that the detailed configuration and operation of the components of the projection system 1, control device 10, projector 20, and detection device 30 in the above embodiment can be appropriately modified without departing from the spirit of the present invention.

[0108] Although embodiments of the present invention have been described, the scope of the present invention is not limited to the embodiments described above, but includes the scope of the invention as described in the claims and its equivalents. The invention described in the claims initially attached to the application for this patent is listed below. The claim numbers listed below are the same as those in the claims initially attached to the application for this patent. [Note] <Claim 1> Based on the detection result of the detection device for an object with a visibility function, it is determined whether the object is located in a first range where the first projection surface reflected in the mirror is visible, and whether the object is located in a second range where the first projection surface is directly visible. If it is determined that the object is located within the first range, the projection device projects a first image onto the first projection surface that is recognized as being in the correct orientation when reflected in the mirror. If it is determined that the object is located within the second range, the projection device projects a second image onto the first projection surface that is recognized as being in a normal orientation when viewed directly. A projection system equipped with a processing unit. <Claim 2> The detection device is A first sensor that detects the target when the target is located within the first range, A second sensor for detecting the target when the target is located within the second range, The projection system according to claim 1, having the following features. <Claim 3> The processing unit projects the first image, whose shape has been corrected so that it is recognized as a normal shape when reflected in the mirror, onto the first projection surface using the projection device. The projection system according to claim 1. <Claim 4> The aforementioned processing unit, If it is determined that the object is located in the first range, and it is also determined that the object is located in the second range, the projection device projects a third image onto a second projection surface that is directly visible to the object located in the first range and the object located in the second range, the third image being recognized as being in a normal orientation when directly viewed. The projection system according to any one of claims 1 to 3. <Claim 5> The aforementioned processing unit, If it is determined that the object is located in the first range, and it is also determined that the object is located in the second range, The number of objects located in the first range and the number of objects located in the second range are counted. If the number of objects located in the first range is greater than the number of objects located in the second range, the projection device will project the first image onto the first projection surface. If the number of objects located in the second range is greater than the number of objects located in the first range, the projection device will project the second image onto the first projection surface. The projection system according to any one of claims 1 to 3. <Claim 6> The first projection plane is located in a position where it is not directly visible to the object located within the first range. The projection system according to claim 1. <Claim 7> A projection method performed by a computer in a projection system, Based on the detection result of the detection device for an object with a visibility function, it is determined whether the object is located in a first range where the first projection surface reflected in the mirror is visible, and whether the object is located in a second range where the first projection surface is directly visible. If it is determined that the object is located within the first range, the projection device projects a first image onto the first projection surface that is recognized as being in the correct orientation when reflected in the mirror. If it is determined that the object is located within the second range, the projection device projects a second image onto the first projection surface that is recognized as being in a normal orientation when viewed directly. Projection method. <Claim 8> In the projection system's computer, A process to determine, based on the detection result of an object having a visual function by a detection device, whether the object is located in a first range where the first projection surface reflected in the mirror is visible, and whether the object is located in a second range where the first projection surface is directly visible. When it is determined that the object is located within the first range, the projection device performs a process of projecting a first image onto the first projection surface that is recognized as being in the correct orientation when reflected in the mirror. When it is determined that the target is located within the second range, the projection device performs a process of projecting a second image onto the first projection surface that is recognized as being in a normal orientation when directly viewed. A program that executes the command. [Explanation of symbols]

[0109] 1. Projection System 10 Control device 11. CPU (Processing Unit, Computer) 12 RAM 13 Storage section 131 Programs 14 Communications Department 15 bus 20. Projector (projection device) 20a enclosure 20b Projection Lens 21 CPU 22 RAM 23 Memory section 231 Programs 232 Image Data 24 Projection section 25 Communications Department 26 bus 30 Detection device 31. First Sensor 32, 32a, 32b Second sensor 41 Image 1 41r mirror image 42. Image 2 43 Third Image 50 mirror 61, 69 Ceiling 62 Floor surface Walls 63-65, 68 66 Corridor 67 Entrance 70 Projection direction adjustment device 71 1st adjustment section 72 Second adjustment section 73 Retaining member 731 Base 731a, 732a Mounting holes 732 Side plate 100 rooms 200 aisles P person R1 First Range R2, R2a, R2b Second Range R3 Third Range S1 1st projection surface S2, S2a, S2b 2nd projection plane S3, S3a, S3b 3rd projection plane S4 4th projection plane

Claims

1. Based on the detection result of the detection device for an object with a visibility function, it is determined whether the object is located in a first range where the first projection surface reflected in the mirror is visible, and whether the object is located in a second range where the first projection surface is directly visible. If it is determined that the object is located within the first range and not within the second range, the projection device projects a first image onto the first projection surface that is recognized as being in the correct orientation when reflected in the mirror. If the object is not determined to be located within the first range and is determined to be located within the second range, the projection device projects a second image onto the first projection surface that is recognized as being in the normal orientation when directly viewed. If it is determined that the object is located in the first range and also in the second range, the projection device projects a third image onto a second projection surface that is directly visible to the object located in the first range and the object located in the second range, the third image being recognized as being in a normal orientation when directly viewed. A projection system equipped with a processing unit.

2. Based on the detection result of an object having a visibility function by the detection device, it is determined whether the object is located in a first range in which the first projection surface reflected in the mirror is visible, and whether the object is located in a second range in which the first projection surface is directly visible. If it is determined that the object is located within the first range and not within the second range, the projection device projects a first image onto the first projection surface that is recognized as being in the correct orientation when reflected in the mirror. If the object is not determined to be located within the first range and is determined to be located within the second range, the projection device projects a second image onto the first projection surface that is recognized as being in the normal orientation when directly viewed. If it is determined that the object is located in the first range and also in the second range, The number of objects located in the first range and the number of objects located in the second range are counted. If the number of objects located in the first range is greater than the number of objects located in the second range, the projection device projects the first image onto the first projection surface. If the number of objects located in the second range is greater than the number of objects located in the first range, the projection device will project the second image onto the first projection surface. A projection system equipped with a processing unit.

3. The detection device is A first sensor for detecting the target when the target is located within the first range, A second sensor for detecting the target when the target is located within the second range, A projection system according to claim 1 or claim 2, comprising:

4. The processing unit projects the first image, whose shape has been corrected so that it is recognized as a normal shape when reflected in the mirror, onto the first projection surface using the projection device. The projection system according to claim 1 or claim 2.

5. The first projection plane is located in a position where it is not directly visible to the object located within the first range. The projection system according to claim 1 or claim 2.

6. A projection method performed by a computer in a projection system, Based on the detection result of the detection device for an object with a visibility function, it is determined whether the object is located in a first range where the first projection surface reflected in the mirror is visible, and whether the object is located in a second range where the first projection surface is directly visible. If it is determined that the object is located within the first range and not within the second range, the projection device projects a first image onto the first projection surface that is recognized as being in the correct orientation when reflected in the mirror. If the object is not determined to be located within the first range and is determined to be located within the second range, the projection device projects a second image onto the first projection surface that is recognized as being in the normal orientation when directly viewed. If it is determined that the object is located in the first range and also in the second range, the projection device projects a third image onto a second projection surface that is directly visible to the object located in the first range and the object located in the second range, the third image being recognized as being in a normal orientation when directly viewed. Projection method.

7. A projection method performed by a computer of a projection system, Based on the detection result of the detection device for an object with a visibility function, it is determined whether the object is located in a first range where the first projection surface reflected in the mirror is visible, and whether the object is located in a second range where the first projection surface is directly visible. If it is determined that the object is located within the first range and not within the second range, the projection device projects a first image onto the first projection surface that is recognized as being in the correct orientation when reflected in the mirror. If the object is not determined to be located within the first range and is determined to be located within the second range, the projection device projects a second image onto the first projection surface that is recognized as being in the normal orientation when directly viewed. If it is determined that the object is located in the first range and also in the second range, The number of objects located in the first range and the number of objects located in the second range are counted. If the number of objects located in the first range is greater than the number of objects located in the second range, the projection device projects the first image onto the first projection surface. If the number of objects located in the second range is greater than the number of objects located in the first range, the projection device will project the second image onto the first projection surface. Projection method.

8. In the projection system's computer, A process to determine, based on the detection result of an object having a visual function by a detection device, whether the object is located in a first range where the first projection surface reflected in the mirror is visible, and whether the object is located in a second range where the first projection surface is directly visible. If it is determined that the object is located within the first range and not within the second range, the projection device performs a process of projecting a first image onto the first projection surface that is recognized as being in the correct orientation when reflected in the mirror. If the object is not determined to be located within the first range and is determined to be located within the second range, the projection device performs a process of projecting a second image onto the first projection surface that is recognized as being in a normal orientation when directly viewed. If it is determined that the object is located in the first range and also in the second range, the projection device performs a process of projecting a third image, which is recognized as being in the normal orientation when directly viewed, onto a second projection surface that is directly visible to the object located in the first range and the object located in the second range. A program that executes the command.

9. The computer of the projection system, A process to determine, based on the detection result of an object having a visual function by a detection device, whether the object is located in a first range where the first projection surface reflected in the mirror is visible, and whether the object is located in a second range where the first projection surface is directly visible. If it is determined that the object is located within the first range and not within the second range, the projection device performs a process of projecting a first image onto the first projection surface that is recognized as being in the correct orientation when reflected in the mirror. If the object is not determined to be located within the first range and is determined to be located within the second range, the projection device performs a process of projecting a second image, which is recognized as being in a normal orientation when directly viewed, onto the first projection surface. If it is determined that the object is located in the first range and also in the second range, The number of objects located in the first range and the number of objects located in the second range are counted. If the number of objects located in the first range is greater than the number of objects located in the second range, the projection device projects the first image onto the first projection surface. If the number of objects located in the second range is greater than the number of objects located in the first range, the projection device performs a process of projecting the second image onto the first projection surface. A program that executes the command.

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