Projection system and control method for projection system

Abstract

To allow sharing of an image projected by a projection device and an image photographed by a projection device between the plurality of devices.SOLUTION: A projection system 100 causes a first projection device to communicate with a second projection device to receive a first received image, project the first received image on a first projection object, photograph a range including the first projection object, remove an image overlapping the first received image from a photographed image of the first projection object to create a first transmission image, and transmit the first transmission image to the second projection device. The projection system causes the second projection device to communicate with the first projection device to receive a second received image, project the second received image on a second projection object, photograph a range including the second projection object, remove an image overlapping the second received image from a photographed image to create a second transmission image, and transmit the second transmission image to the first projection device.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a projection system and a control method for a projection system. [Background technology]

[0002] Conventionally, there are known techniques for drawing characters or the like by superimposing them on an image projected by a projector. For example, a device disclosed in Patent Document 1 detects handwritten characters superimposed on an image projected on a screen by photographing the screen with a camera. This device records the detected character data on a recording medium in association with the projected video data, thereby reproducing the video data with the handwritten characters superimposed. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2015-161748 Summary of the Invention [Problem to be solved by the invention]

[0004] The device described in Patent Document 1 requires data recorded on a recording medium to play back video data and handwritten characters. With this configuration, it is difficult to share images projected by the projector or images captured by the projector among multiple devices. [Means for solving the problem]

[0005] One aspect of the present disclosure is a projection system including a first projection device and a second projection device, wherein the first projection device includes a first communication unit that communicates with the second projection device to receive a first received image, a first projection unit that projects the first received image onto a first projection target, and a first capture unit that captures an image of an area including the first projection target, and generates a first transmission image by removing an image that overlaps the first received image from a first captured image captured by the first capture unit, and a second projection device that transmits a second received image by the first communication unit, and the second projection device that has a second communication unit that communicates with the first projection device to receive a second received image, a second projection unit that projects the second received image onto a second projection target, and a second capturing unit that captures an area including the second projection target, and that generates a second transmitted image by removing an image that overlaps the second received image from the second captured image captured by the second capturing unit, and transmits the second transmitted image by the second communication unit.

[0006] Another aspect of the present disclosure is a control method for a projection system including a first projection device and a second projection device, the control method including: using the first projection device to communicate with the second projection device to receive a first received image; projecting the first received image onto a first projection target; capturing an image of an area including the first projection target; generating a first transmitted image by removing an image that overlaps with the first received image from a first captured image of the first projection target; transmitting the first transmitted image to the second projection device; using the second projection device to communicate with the first projection device to receive a second received image; projecting the second received image onto a second projection target; capturing an image of an area including the second projection target; generating a second transmitted image by removing an image that overlaps with the second received image from a second captured image of the second projection target; and transmitting the second transmitted image to the first projection device. [Brief explanation of the drawings]

[0007] [Figure 1]FIG. 1 is a diagram showing a schematic configuration of a projection system according to a first embodiment. [Figure 2] FIG. 2 is a block diagram of each device of the projection system according to the first embodiment. [Figure 3] FIG. 2 is a schematic diagram showing an example of the configuration of a projection unit and an imaging unit. [Figure 4] FIG. 10 is a schematic diagram showing another example of the configuration of the projection unit and the imaging unit. [Figure 5] FIG. 3 is a sequence diagram showing the operation of the projection system according to the first embodiment. [Figure 6] 6 is a flowchart showing the operation of the first projection device of the first embodiment. [Figure 7] FIG. 2 is a schematic diagram illustrating the operation of the projection system according to the first embodiment. [Figure 8] FIG. 10 is a diagram showing a schematic configuration of a projection system according to a second embodiment. [Figure 9] FIG. 10 is a block diagram of each device of a projection system according to a second embodiment. [Figure 10] 10 is a flowchart showing the operation of the second projection device of the second embodiment. [Figure 11] FIG. 10 is a schematic diagram illustrating the operation of the projection system according to the second embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0008] [1. First embodiment] [1-1. Projection system configuration] 1 is a diagram showing a schematic configuration of a projection system 100 according to the first embodiment. The projection system 100 includes a first projection device 1 and a second projection device 2. The first projection device 1 and the second projection device 2 are connected to each other via a communication network N so as to be able to communicate data with each other.

[0009] There are no restrictions on the installation locations of the first projection device 1 and the second projection device 2; for example, the usage location S1 of the first projection device 1 and the usage location S2 of the second projection device 2 may be located far apart or close to each other.

[0010] The communication network N is a network that enables data communication between devices. The communication network N may be, for example, a local network such as a LAN (Local Area Network) or a wide area network. The communication network N may also be, for example, an open network such as the Internet. The communication network N may include communication lines such as dedicated lines, public lines, and cellular communication lines, and communication devices such as routers and gateway devices. The first projection device 1 and the communication network N may be connected via a communication cable in a wired manner, or may be connected wirelessly via a wireless communication path. Similarly, the second projection device 2 and the communication network N may be connected via a communication cable in a wired manner, or may be connected wirelessly via a wireless communication path. The communication cable may be, for example, a LAN cable or a USB cable conforming to the USB (Universal Serial Bus) communication standard. The wireless communication path may be, for example, Wi-Fi or Bluetooth. Wi-Fi is a registered trademark. Bluetooth is a registered trademark.

[0011] The first projection device 1 projects image light PL1 toward the first projection target OB1, forming a projection image PP1 on the first projection target OB1. The first projection device 1 projecting image light PL1 corresponds to displaying a projection image PP1 on the first projection target OB1. The second projection device 2 projected image light PL2 toward the second projection target OB2, forming a projection image PP2 on the second projection target OB2. The second projection device 2 projecting image light PL2 corresponds to displaying a projection image PP2 on the second projection target OB2. In the following description, the term "image" includes video and still images.

[0012] FIG. 1 shows a configuration in which a first projection device 1 is installed above a first projection target OB1 and projects image light PL1 downward from the first projection device 1. The first projection target OB1 includes, for example, a plane OB11 and an object OB12 placed on the plane OB11. Similarly, a second projection device 2 is installed above a second projection target OB2 and projects image light PL2 downward. The second projection target OB2 includes a plane OB21 and an object OB22 placed on the plane OB21. The configuration in FIG. 1 is an example, and the planes OB11 and OB21 may be curved surfaces or surfaces with irregularities. The position and orientation of the first projection device 1 are determined depending on the positional relationship with the first projection target OB1. For example, the first projection device 1 may be installed in an orientation to project image light PL1 horizontally or upward. The same applies to the second projection device 2.

[0013] The first projection device 1 has a function of capturing an image of the first projection target OB1. The first projection device 1 transmits the captured image of the first projection target OB1 to the second projection device 2 via the communication network N. The second projection device 2 also has a function of capturing an image of the second projection target OB2. The second projection device 2 transmits the captured image of the second projection target OB2 to the first projection device 1 via the communication network N. The first projection device 1 and the second projection device 2 can clearly share images, including hand-drawn images and captured images, respectively.

[0014] [1-2. Projection device configuration] FIG. 2 is a block diagram of each device in the projection system 100. First, the configuration of the first projection device 1 will be described. The first projection device 1 includes a first projection unit 110 that projects image light PL1 and a drive circuit 113 that drives the first projection unit 110. The first projection unit 110 includes an image light formation unit 111 and a projection optical system 112.

[0015] The image light forming section 111 generates the image light PL1. The image light forming section 111 includes self-emitting elements that emit predetermined colored light. The predetermined colored light is, for example, red light, blue light, and green light. The self-emitting elements include, for example, LED (Light Emitting Diode) elements or OLED (Organic LED) elements. The configuration of the image light forming section 111 will be described later.

[0016] The image light forming unit 111 may be configured to include, for example, a light source having a lamp or a solid-state light source, and a light modulation device that modulates the light emitted by the light source. Examples of the lamp include a halogen lamp, a xenon lamp, and an ultra-high pressure mercury lamp. Examples of the solid-state light source include an LED and a laser light source. Examples of the light modulation device include a transmissive liquid crystal panel, a reflective liquid crystal panel, and a digital micromirror device (DMD).

[0017] The projection optical system 112 includes optical elements that guide the image light PL1 emitted by the image light formation unit 111 toward the first projection target OB1. The optical elements include a single lens or a lens group including multiple lenses. The optical elements may include a prism and a dichroic mirror. Alternatively, the optical elements may be reflective optical elements such as mirrors.

[0018] The drive circuit 113 is connected to the image processing unit 143, which will be described later. The drive circuit 113 forms the image light PL1 by driving the image light formation unit 111 based on an image signal input from the image processing unit 143. For example, the drive circuit 113 forms an image by the image light formation unit 111 on a frame-by-frame basis.

[0019] The first projection device 1 includes a first image capturing unit 115. The first image capturing unit 115 is a digital camera having an image capturing element. The first image capturing unit 115 captures images under the control of a first control unit 120, which will be described later, and outputs the captured image to the first control unit 120. The image capturing range of the first image capturing unit 115 includes the direction in which the first projection unit 110 projects the image light PL1. For example, the image capturing range of the first image capturing unit 115 includes the first projection target OB1. The image capturing element included in the first image capturing unit 115 is, for example, a CMOS (Complementary Metal Oxide Semiconductor) image sensor or a CCD (Charge Coupled Device) image sensor. The configuration of the first image capturing unit 115 will be described later together with the first projection unit 110.

[0020] The first projection device 1 includes a first control unit 120, an operation unit 131, a remote control light receiving unit 132, an input interface 133, a connection unit 141, a first communication unit 142, and an image processing unit 143. The first control unit 120, the input interface 133, the connection unit 141, the first communication unit 142, and the image processing unit 143 are connected to each other via a bus 139 so as to be able to communicate data with each other.

[0021] The operation unit 131 includes various buttons and switches provided on the surface of the housing of the first projection device 1. The operation unit 131 generates operation signals corresponding to the operation of the buttons or switches, and outputs the operation signals to the input interface 133. The input interface 133 includes a circuit that outputs the operation signals input from the operation unit 131 to the first control unit 120.

[0022] The remote control light receiving unit 132 includes a light receiving element that receives infrared light, and receives an infrared signal transmitted from the remote control 41. When a switch (not shown) provided on the remote control 41 is operated, the remote control 41 transmits an infrared signal indicating the operation. The remote control light receiving unit 132 decodes the received infrared signal to generate an operation signal. The remote control light receiving unit 132 outputs the generated operation signal to the input interface 133. The input interface 133 includes a circuit that outputs the operation signal input from the remote control light receiving unit 132 to the first control unit 120.

[0023] There are no limitations on the specific manner in which signals are transmitted and received between the remote control 41 and the remote control light receiving unit 132. The configuration in which the remote control 41 transmits an infrared signal to the remote control light receiving unit 132 is one example. For example, the remote control 41 and the remote control light receiving unit 132 may transmit and receive signals by performing short-range wireless communication such as Bluetooth.

[0024] The connection unit 141 is an interface device that receives image data from an external device, and is connected to, for example, a player that plays back an optical disc type recording medium or a personal computer.

[0025] The first communication unit 142 is connected to a communication network N and transmits and receives data to and from the second projection device 2 via the communication network N. The first communication unit 142 is, for example, a communication device including a connector for connecting a communication cable and a communication circuit for inputting and outputting signals via the communication cable. Alternatively, the first communication unit 142 may be a wireless communication device. In this case, the first communication unit 142 includes, for example, an antenna, an RF (Radio Frequency) circuit, a baseband circuit, etc.

[0026] The image processing unit 143 selects an image source under the control of the first control unit 120. Sources available to the first projection device 1 include, for example, image data received by the connection unit 141 and image data received by the first communication unit 142.

[0027] The image processing unit 143 performs image processing on the image data of the selected source under the control of the first control unit 120. The image processing performed by the image processing unit 143 includes, for example, resolution conversion processing, geometric correction processing, digital zoom processing, and image correction processing for adjusting the color tone and brightness of the image.

[0028] The image processing unit 143 generates an image signal based on the image data after image processing and outputs it to the drive circuit 113. A frame memory (not shown) may be connected to the image processing unit 143. In this case, the image processing unit 143 loads the image data acquired from the source into the frame memory. The image processing unit 143 performs image processing on the image data loaded into the frame memory.

[0029] The image processing unit 143 can be configured, for example, by an integrated circuit. The integrated circuit is configured, for example, by an LSI (Large Scale Integration). More specifically, the image processing unit 143 is configured, for example, by an ASIC (Application Specific Integrated Circuit), a PLD (Programmable Logic Device), or the like. The PLD includes, for example, an FPGA (Field-Programmable Gate Array). Furthermore, an analog circuit may be included as part of the configuration of the integrated circuit, or the integrated circuit may be a combination of a processor and an integrated circuit. The combination of a processor and an integrated circuit is called a microcontroller (MCU), a SoC (System-on-a-Chip), a system LSI, a chipset, or the like.

[0030] The first control unit 120 includes a processor 121 and a memory 125. The memory 125 is a storage device that stores programs and data executed by the processor 121 in a nonvolatile manner. The memory 125 is configured by a semiconductor storage element such as a magnetic storage device or a flash ROM (Read Only Memory), or other types of nonvolatile storage device. The memory 125 may include a RAM (Random Access Memory) that configures the work area of ​​the processor 121. The memory 125 stores data processed by the processor 121 and a control program 126 executed by the processor 121.

[0031] The processor 121 is configured with a CPU (Central Processing Unit), an MPU (Micro-processing unit), or the like. The processor 121 may be configured with a single processor, or multiple processors may function as the processor 121. The processor 121 may be configured as an SoC integrated with part or all of the memory 125 and / or other circuits. As described above, the processor 121 may be configured by combining a CPU that executes a program and a DSP (Digital Signal Processor) that executes predetermined arithmetic processing. All of the functions of the processor 121 may be implemented in hardware, or may be configured using a programmable device. The processor 121 may also have the functions of the image processing unit 143. In other words, the functions of the image processing unit 143 may be executed by the processor 121.

[0032] The processor 121 controls each part of the first projection device 1 by executing a control program 126 stored in the memory 125. The processor 121 has a projection control unit 122 and a first filter 123. These are functional parts that are realized by the processor 121 executing the control program 126 through cooperation between hardware and software.

[0033] The projection control unit 122 receives an image transmitted from the second projection device 2 via the first communication unit 142. The image received by the first communication unit 142 from the second projection device 2 is referred to as the first received image. The projection control unit 122 projects an image based on the first received image onto the first projection target OB1 via the first projection unit 110. The projection control unit 122 causes the first capture unit 115 to capture an area including the first projection target OB1 and acquires the captured image. The projection control unit 122 performs filtering using the first filter 123 on the image captured by the first capture unit 115, and transmits the transmission image generated by the filtering to the second projection device 2 via the first communication unit 142. The image captured by the first capture unit 115 is referred to as the first captured image. Furthermore, the image generated by filtering the first captured image and transmitted to the second projection device 2 by the first communication unit 142 is referred to as the first transmitted image.

[0034] The first filter 123 filters the first captured image based on the first received image. In detail, the first filter 123 performs processing to remove an image that overlaps with the first received image from the first captured image.

[0035] Next, the configuration of the second projection device 2 will be described. The second projection device 2 includes a second projection section 210 that projects the image light PL2, and a drive circuit 213 that drives the second projection section 210. The second projection section 210 includes an image light formation section 211 and a projection optical system 212.

[0036] The image light forming section 211 generates the image light PL2. The image light forming section 211 includes a self-emitting element that emits light of a predetermined color. Examples of the self-emitting element include an LED element or an OLED element.

[0037] The image light forming unit 211 may include, for example, a light source having a lamp or a solid-state light source, and a light modulation device that modulates the light emitted by the light source. Examples of the light modulation device include a transmissive liquid crystal panel, a reflective liquid crystal panel, or a digital micromirror device. The optical element may also be a reflective optical element.

[0038] The projection optical system 212 includes optical elements that guide the image light PL2 emitted by the image light formation unit 211 toward the second projection target OB2. The optical elements include a lens group including one lens or multiple lenses. The optical elements may also include a prism and a dichroic mirror.

[0039] The drive circuit 213 is connected to the image processing unit 243, which will be described later. The drive circuit 213 forms the image light PL2 by driving the image light formation unit 211 based on an image signal input from the image processing unit 243. For example, the drive circuit 213 forms an image by the image light formation unit 211 on a frame-by-frame basis.

[0040] The second projection device 2 includes a second image capturing unit 215. The second image capturing unit 215 is a digital camera having an image capturing element. The second image capturing unit 215 captures images under the control of a second control unit 220, which will be described later, and outputs the captured image to the second control unit 220. The image capturing range of the second image capturing unit 215 includes the direction in which the second projection unit 210 projects the image light PL2. For example, the image capturing range of the second image capturing unit 215 includes the second projection target OB2. The image capturing element included in the second image capturing unit 215 is, for example, a CMOS image sensor or a CCD image sensor.

[0041] The configurations of the image light forming unit 211, the projection optical system 212, the drive circuit 213, and the second photographing unit 215 can be the same as the configurations of the image light forming unit 111, the projection optical system 112, the drive circuit 113, and the first photographing unit 115 that are provided in the first projection device 1, respectively.

[0042] The second projection device 2 includes a second control unit 220, an operation unit 231, a remote control light receiving unit 232, an input interface 233, a connection unit 241, a second communication unit 242, and an image processing unit 243. The second control unit 220, the input interface 233, the connection unit 241, the second communication unit 242, and the image processing unit 243 are connected to each other via a bus 239 so as to be able to communicate data with each other.

[0043] The operation unit 231 includes various buttons and switches provided on the surface of the housing of the second projection device 2. The operation unit 231 generates operation signals corresponding to the operation of the buttons or switches, and outputs the operation signals to the input interface 233. The input interface 233 includes a circuit that outputs the operation signals input from the operation unit 231 to the second control unit 220.

[0044] The remote control light receiving unit 232 includes a light receiving element that receives infrared light, and receives an infrared signal transmitted from the remote control 42. When a switch (not shown) provided on the remote control 42 is operated, the remote control 42 transmits an infrared signal indicating the operation. The remote control light receiving unit 232 decodes the received infrared signal to generate an operation signal. The remote control light receiving unit 232 outputs the generated operation signal to the input interface 233. The input interface 233 includes a circuit that outputs the operation signal input from the remote control light receiving unit 232 to the second control unit 220.

[0045] There are no limitations on the specific manner in which signals are transmitted and received between the remote control 42 and the remote control light receiving unit 232. The configuration in which the remote control 42 transmits an infrared signal to the remote control light receiving unit 232 is one example. For example, the remote control 42 and the remote control light receiving unit 232 may transmit and receive signals by performing short-range wireless communication such as Bluetooth.

[0046] The connection unit 241 is an interface device that receives image data from an external device, and is connected to, for example, a player that plays back an optical disc type recording medium or a personal computer.

[0047] The second communication unit 242 is connected to the communication network N and transmits and receives data to and from the first projection device 1 via the communication network N. The second communication unit 242 is, for example, a communication device including a connector for connecting a communication cable and a communication circuit for inputting and outputting signals via the communication cable. Alternatively, the second communication unit 242 may be a wireless communication device. In this case, the second communication unit 242 includes, for example, an antenna, an RF circuit, a baseband circuit, etc.

[0048] The image processing unit 243 selects an image source under the control of the second control unit 220. Sources available to the second projection device 2 are, for example, images received by the connection unit 241 and images received by the second communication unit 242.

[0049] The image processing unit 243 performs image processing on the image of the selected source under the control of the second control unit 220. The image processing performed by the image processing unit 243 includes, for example, resolution conversion processing, geometric correction processing, digital zoom processing, and image correction processing for adjusting the color tone and brightness of the image.

[0050] The image processing unit 243 generates an image signal based on the image data after image processing and outputs it to the drive circuit 213. A frame memory (not shown) may be connected to the image processing unit 243. In this case, the image processing unit 243 loads an image acquired from a source into the frame memory. The image processing unit 243 performs image processing on the image loaded into the frame memory.

[0051] The image processing unit 243 can be configured, for example, by an integrated circuit. The integrated circuit is configured, for example, by an LSI. More specifically, the image processing unit 243 is configured by an ASIC, a PLD, or the like. The PLD includes, for example, an FPGA. Furthermore, an analog circuit may be included as part of the configuration of the integrated circuit, or the integrated circuit may be a combination of a processor and an integrated circuit. Examples of the combination of a processor and an integrated circuit include a microcontroller, an SoC, a system LSI, and a chipset.

[0052] The configurations of the operation unit 231, the remote control light receiving unit 232, and the input interface 233 can be the same as those of the operation unit 131, the remote control light receiving unit 132, and the input interface 133, respectively. Similarly, the configurations of the connection unit 241, the second communication unit 242, and the image processing unit 243 can be the same as those of the connection unit 141, the first communication unit 142, and the image processing unit 143, respectively.

[0053] The second control unit 220 includes a processor 221 and a memory 225. The memory 225 is a storage device that stores programs and data executed by the processor 221 in a nonvolatile manner. The memory 225 is configured from a magnetic storage device, a semiconductor storage element such as a flash ROM, or other types of nonvolatile storage device. The memory 225 may include a RAM that configures the work area of ​​the processor 221. The memory 225 stores data processed by the processor 221 and a control program 226 executed by the processor 221.

[0054] The processor 221 is configured with a CPU, an MPU, or the like. The processor 221 may be configured with a single processor, or multiple processors may function as the processor 221. The processor 221 may be configured with an SoC integrated with part or all of the memory 225 and / or other circuits. As described above, the processor 221 may be configured with a combination of a CPU that executes a program and a DSP that executes predetermined arithmetic processing. All of the functions of the processor 221 may be implemented in hardware, or may be configured using a programmable device. The processor 221 may also have the functions of the image processing unit 243. In other words, the processor 221 may execute the functions of the image processing unit 243.

[0055] The processor 221 controls each part of the second projection device 2 by executing a control program 226 stored in the memory 225. The processor 221 has a projection control unit 222 and a second filter 223. These are functional parts that are realized by the processor 221 executing the control program 226 through cooperation between hardware and software.

[0056] The projection control unit 222 receives an image transmitted by the first projection device 1 via the second communication unit 242. The image received by the second communication unit 242 from the first projection device 1 is referred to as a second received image. The projection control unit 222 projects an image based on the second received image onto the second projection target OB2 via the second projection unit 210. The projection control unit 222 then causes the second capture unit 215 to capture an area including the second projection target OB2 and acquires the captured image. The projection control unit 222 then filters the captured image by the second capture unit 215 using the second filter 223, and transmits the transmitted image generated by the filtering to the first projection device 1 via the second communication unit 242. The captured image by the second capture unit 215 is referred to as a second captured image. The image generated by filtering the second captured image and transmitted to the first projection device 1 by the second communication unit 242 is referred to as a second transmitted image.

[0057] The second filter 223 filters the second captured image based on the second received image. Specifically, the second filter 223 performs processing to remove an image that overlaps with the second received image from the second captured image.

[0058] [1-3. Configuration of the projection unit and the shooting unit] FIG. 3 is a schematic diagram showing an example of the configuration of the first projection unit 110 and the first image capturing unit 115. As shown in FIG. The projection optical system 112 includes a separation optical element 151 and a projection lens 152. The optical axis of the image light PL1 projected by the projection lens 152 toward the first projection target OB1 is indicated by the symbol AX. The optical axis AX is the central axis of the image light PL1 irradiated from the projection lens 152 onto the first projection target OB1, and is a virtual axis that passes through the optical center of the projection lens 152 and follows the direction in which the image light PL1 is irradiated from the projection lens 152.

[0059] The image light forming unit 111 includes a light emitting device 161. The light emitting device 161 has light emitting elements arranged in a row on a light emitting surface 162. The light emitting elements arranged on the light emitting surface 162 include a light emitting element that emits red light, a light emitting element that emits blue light, and a light emitting element that emits green light. By arranging these light emitting elements in a matrix, the light emitting device 161 emits image light PL1 that forms an image from the light emitting surface 162.

[0060] The light-emitting surface 162 faces the separation optical element 151. The image light PL1 emitted by the light-emitting surface 162 enters the separation optical element 151 along the optical axis AX, passes through the separation optical element 151, and enters the projection lens 152. The projection lens 152 irradiates the image light PL1 that has passed through the separation optical element 151 onto the first projection target OB1. The optical axis of the image light PL1 emitted by the light-emitting surface 162 is defined as the projection optical axis PAX. The projection optical axis PAX is the central axis of the image light PL1 emitted by the light-emitting device 161, and is a virtual axis that passes through the center of the area in which the light-emitting elements are arranged on the light-emitting surface 162 and is perpendicular to the light-emitting surface 162. In the configuration of FIG. 3, the projection optical axis PAX coincides with the optical axis AX. In other words, the light-emitting device 161 is arranged on the optical axis AX of the projection optical system 112.

[0061] The first photographing unit 115 includes an imaging device 171. The imaging device 171 is disposed opposite the separation optical element 151. In the imaging device 171, imaging elements are disposed side by side on an imaging surface 172 facing the separation optical element 151. The first photographing unit 115 photographs an image by each imaging element disposed on the imaging surface 172 receiving light incident from the separation optical element 151. The imaging device 171 faces a surface of the separation optical element 151 different from the surface of the light-emitting device 161. In detail, the light-emitting device 161 is disposed so as to be aligned with the separation optical element 151 in a direction along the optical axis AX. In contrast, the imaging device 171 faces the separation optical element 151 at an angle of 90 degrees with respect to the optical axis AX.

[0062] The separation optical element 151 transmits light emitted by the light emitting device 161 to make it incident on the projection lens 152, and also reflects light that has entered the separation optical element 151 from the projection lens 152 toward the imaging device 171. The separation optical element 151 can be, for example, a polarization separation element. The separation optical element 151 may also be configured with a dichroic mirror or a dichroic prism.

[0063] The optical axis of light reflected by the separation optical element 151 toward the imaging device 171 is indicated by the symbol IAX. The imaging optical axis IAX is the central axis of light traveling from the separation optical element 151 toward the imaging device 171, and is the axis of light received by the imaging device 171 at its imaging surface 172. The imaging optical axis IAX is a virtual axis perpendicular to the imaging surface 172. In other words, the imaging device 171 is disposed so that the center of the imaging surface 172 coincides with the imaging optical axis IAX.

[0064] The photographing optical axis IAX coincides with the optical axis AX until it is reflected inside the separation optical element 151 . That is, in an area closer to the first projection target OB1 than the projection optical system 112, the projection optical axis PAX of the image light PL1 emitted by the image light formation unit 111 coincides with the imaging optical axis IAX of the light received by the first imaging unit 115. In this way, the first projection unit 110 and the first imaging unit 115 are optically arranged on the same axis. That is, the first projection unit 110 and the first imaging unit 115 project and capture the image light PL1 on the same axis.

[0065] 3 is a schematic diagram, and the first projection unit 110, the projection optical system 112, and the first capturing unit 115 may include components not shown in Fig. 3. For example, the projection optical system 112 may include optical elements other than the separation optical element 151 and the projection lens 152. For example, the projection optical system 112 may include a light guiding element between the separation optical element 151 and the projection lens 152. A polarization separation element and a polarization conversion element may be provided between the light emitting device 161 and the separation optical element 151 to adjust the polarization of the image light PL1 incident on the separation optical element 151.

[0066] FIG. 4 is a schematic diagram showing another example of the configuration of the first projection unit 110 and the first image capturing unit 115. In FIG. This configuration example uses a light receiving and emitting device 18 that integrates a first projection unit 110 and a first image capturing unit 115. In the example of Fig. 4, the projection optical system 112 does not have a separation optical element 151. The projection lens 152 in Fig. 4 may be the same as the projection lens 152 illustrated in Fig. 3, or may have a different configuration.

[0067] The light emitting and receiving device 18 is disposed on the optical axis AX of the projection lens 152. The light emitting and receiving device 18 has a light emitting element and a light receiving element on a light emitting and receiving surface 18a facing the projection lens 152. That is, as shown enlarged in circle A in Fig. 4, a blue light emitting element 181, a red light emitting element 182, a green light emitting element 183, and an imaging element 185 are disposed on the light emitting and receiving surface 18a.

[0068] The blue light-emitting element 181, the red light-emitting element 182, and the green light-emitting element 183 are configured, for example, by LEDs or OLEDs. The blue light-emitting element 181 is an element that emits light in a blue wavelength region, the red light-emitting element 182 is an element that emits light in a red wavelength region, and the green light-emitting element 183 is an element that emits light in a green wavelength region. In the example of FIG. 4, one pixel region 180 is configured by two blue light-emitting elements 181, one red light-emitting element 182, and one green light-emitting element 183. The pixel region 180 is an area that forms one pixel included in an image formed by the light-receiving and light-emitting device 18. The pixel region 180 forms the color of one pixel by two blue light-emitting elements 181, one red light-emitting element 182, and one green light-emitting element 183.

[0069] The light receiving and emitting surface 18a includes one image sensor 185 per pixel region 180. The image sensor 185 is an element made of a CMOS or a CCD, and receives light incident on the light receiving and emitting surface 18a. The first photographing unit 115 photographs an image by receiving light with the image sensor 185.

[0070] In this way, the light emitting and receiving device 18 functions as an image light forming unit 111 that forms image light PL1, and as a first capturing unit 115 that captures images. The optical axis of the image light PL1 emitted by the light emitting and receiving device 18 is optical axis AX, and the first capturing unit 115 captures images using light that is incident along the optical axis AX. In the configuration of FIG. 4, similar to the configuration shown in FIG. 3, the first projection unit 110 and the first capturing unit 115 are optically arranged on the same axis, and the first projection unit 110 and the first capturing unit 115 perform projection and capture along the same axis.

[0071] The configuration of the first projection unit 110 and the first image capturing unit 115 shown in FIG. 3 can be applied to the second projection unit 210 and the second image capturing unit 215. That is, the image light formation unit 211 of the second projection unit 210 can include the light emitting device 161, the projection optical system 212 can include the separation optical element 151 and the projection lens 152, and the second image capturing unit 215 can include the image capturing device 171. Similarly, the configuration shown in FIG. 4 can be applied to the second projection unit 210 and the second image capturing unit 215. In this case, the second projection unit 210 and the second image capturing unit 215 can be configured to include the light emitting and receiving device 18 and the projection lens 152 of FIG. 4. With these configurations, the projection system 100 can function as a system in which images are shared between the first projection device 1, which performs projection and image capturing on the same axis, and the second projection device 2, which performs projection and image capturing on the same axis.

[0072] [1-4. Projection System Operation] Fig. 5 is a sequence diagram showing the operation of the projection system 100. Fig. 6 is a flowchart showing the operation of the projection apparatus, here showing the operation of the first projection apparatus 1. Fig. 7 is a schematic diagram showing the operation of the projection system 100. The operation of the projection system 100 will be described with reference to these figures.

[0073] 5, the processes of steps SA11 to SA16 are executed by the first control unit 120 of the first projection device 1, and the processes of steps SB11 to SB16 are executed by the second control unit 220 of the second projection device 2. The images transmitted and received by the first projection device 1 to the second projection device 2 are the first transmitted image and the first received image, respectively. The images transmitted and received by the second projection device 2 to and from the first projection device 1 are the second transmitted image and the second received image, respectively. Furthermore, the images captured by the first projection device 1 and the second projection device 2 are the first captured image and the second captured image, respectively.

[0074] In step SA11, the first projection device 1 captures an image of an area including the first projection target OB1 and generates a first captured image. In step SA12, the first projection device 1 executes a transmission image generation process to generate a first transmission image. The transmission image generation process will be described later with reference to FIG. 6. In step SA13, the first projection device 1 transmits the first transmission image to the second projection device 2. For example, this state is shown by image SP11 in FIG. 7.

[0075] In step SB11, the second projection device 2 receives the image transmitted by the first projection device 1. The image received by the second projection device 2 in step SB11 is the second received image. In step SB12, the second projection device 2 projects the received second received image onto the second projection target OB2 using the second projection unit 210.

[0076] In step SB13, the second projection device 2 captures an image of an area including the second projection target OB2 to generate a second captured image. In step SB14, the second projection device 2 executes a transmission image generation process based on the second captured image to generate a second transmission image, which is a processed image. The transmission image generation process executed by the second projection device 2 in step SB14 is the same as the process executed by the first projection device 1 in step SA12. More specifically, this process uses the second captured image instead of the first captured image and the second received image instead of the first received image to generate a second transmission image. In step SB15, the second projection device 2 transmits the second transmission image to the first projection device 1. For example, this state is shown by image SP21 in FIG. 7.

[0077] In step SA14, the first projection device 1 receives the image transmitted by the second projection device 2. The image received by the first projection device 1 in step SA14 is the first received image. In step SA15, the first projection device 1 projects the received first received image onto the first projection target OB1 using the first projection unit 110.

[0078] In step SA16, the first projection device 1 determines whether to end the operation. If the first projection device 1 determines to end the operation (step SA16; YES), such as when an operation instructing to end the operation is detected by the input interface 133, the first projection device 1 ends this process. If the first projection device 1 determines not to end the operation (step SA16; NO), the first projection device 1 returns to step SA11.

[0079] In step SB16, the second projection device 2 determines whether to end the operation. If the second projection device 2 determines to end the operation (step SB16; YES), such as when an operation instructing to end the operation is detected via the input interface 233, the second projection device 2 ends this process. If the second projection device 2 determines not to end the operation (step SB16; NO), the second projection device 2 returns to step SB11.

[0080] 6 shows in detail the transmission image generation process executed by the first projection device 1 in step SA12. The processes of steps SA21 to SA24 in FIG.

[0081] In step SA21, the first projection device 1 acquires the first captured image captured by the first image capturing unit 115. In step SA22, the first received image received before step SA21 is acquired. For example, in the transmission image generation process when steps SA11 to SA16 shown in FIG. 5 are executed for the second time, the first projection device 1 acquires the first received image received in step SA14 executed for the first time.

[0082] In step SA23, the first projection device 1 removes, from the first captured image obtained in step SA21, an image that overlaps with the first received image obtained in step SA22. In step SA23, the first projection device 1, for example, filters the first captured image obtained in step SA21 using the first filter 123. The first filter 123 filters the first captured image based on the first received image, thereby outputting an image from which the image that overlaps with the first received image has been removed. In step SA24, the first projection device 1 stores the image after the image removal process in the memory 125 as the first transmitted image. For example, in step SA24, the first projection device 1 designates the image output by the first filter 123 as the first transmitted image. The first transmitted image stored in the memory 125 in step SA24 is transmitted to the second projection device 2 in step SA13, as described above.

[0083] Here, the first filter 123, for example, superimposes the first received image and the first captured image, and eliminates the image that overlaps the first received image and the first captured image before outputting the image.

[0084] An image in the first captured image that overlaps with the first received image includes an image whose size, position, and shape are completely identical. The first filter 123 may also remove from the first captured image an image whose size, position, or shape differs from an image included in the first received image. In this case, the first control unit 120 may have a threshold value that defines an acceptable range for differences in image size, position, and shape. For example, the first control unit 120 may determine that the images overlap when the amount of difference in image size, position, and shape is smaller than the threshold value. The first filter 123 may also perform a process of removing an image based on whether the colors of the images match.

[0085] Furthermore, for example, the first filter 123 may process the first captured image by recognizing image objects included in the first received image and image objects included in the first captured image. An image object refers to a group of images such as a figure or a character. Specifically, the first filter 123 removes the background from the first received image and extracts image objects included in the image after background removal. The first filter 123 removes the background from the first captured image and extracts image objects included in the image after background removal. The first filter 123 compares the image objects extracted from the first received image with the image objects extracted from the first captured image to identify matching image objects. The first filter 123 removes the identified image objects from the first captured image. For example, this state is shown in image SP12 in FIG. 7.

[0086] In step SB14, the second projection device 2 executes processing similar to the transmission image generation processing shown in FIG. 6. That is, the second projection device 2 acquires the second captured image captured by the second image capturing unit 215 in step SB14, and acquires the second received image received in step SB11. The second projection device 2 performs filtering using, for example, the second filter 223, and removes an image that overlaps with the second received image from the second captured image. The second projection device 2 stores the processed image processed by the second filter 223 in the memory 225 as the processed image. The processed image stored in the memory 225 is transmitted to the first projection device 1 as the second transmission image in step SB15.

[0087] In this way, the first projection device 1 transmits a first transmission image obtained by removing an image that overlaps with the first received image from the first captured image to the second projection device 2. Similarly, the second projection device 2 transmits a second transmission image, which is a processed image obtained by removing an image that overlaps with the second received image from the second captured image, to the first projection device 1. These processes have the effect of improving the visibility of the projection images projected onto the first projection target OB1 and the second projection target OB2.

[0088] 7 shows a viewing state ST1 of the first projection target OB1 of the first projection device 1 and a viewing state ST2 of the second projection target OB2 of the second projection device 2. Also shown are images SP11, SP21, and SP12 transmitted and received between the first projection device 1 and the second projection device 2.

[0089] As shown in Fig. 1, an object OB12 is placed on a plane OB11 of the first projection target OB1 of the first projection device 1. This visual state is shown in the upper part of ST1 in Fig. 7, and the actual object OB12 is visually recognized. In addition, paper or the like is placed on the plane OB11, and a user using the first projection device 1 can write characters or figures on the plane OB1 with a writing implement.

[0090] An object OB22 is placed on a plane OB21 of the second projection target OB2 of the second projection device 2. This state is not shown in Fig. 7. Also, like the plane OB11, a piece of paper or the like is placed on the plane OB21, so that a user of the second projection device 2 can write characters or figures on the plane OB21 with a writing implement.

[0091] The first projection device 1 captures an image of the first projection target OB1 using the first image capturing unit 115 to generate a first captured image. The first captured image includes an object image OP1 that is an image of the object OB12. The first projection device 1 generates a first transmission image by filtering the first captured image using the first filter 123. The first projection device 1 transmits the first transmission image to the second projection device 2 as an image SP11. This state is shown as image SP11 in FIG. 7.

[0092] The second projection device 2 receives the image SP11 as a second received image. The second projection device 2 projects the second received image onto the second projection target OB2 using the second projection unit 210. At this time, an object OB22 is present on the second projection target OB2, and an object image OP1 is projected onto the object OB2. This visual state is shown in the upper part of ST2 in FIG. 7, where the actual object OB22 and the object image OP1, which is a projected image of the object OB12, are visually recognized.

[0093] The second projection device 2 captures an image of the second projection target OB2 using the second image capturing unit 215 to generate a second captured image. The second captured image includes an object image OP2, which is an image of the object OB22, and an object image OP1. The second projection device 2 generates a processed image by removing an image that overlaps with the first transmitted image from the second captured image. The processed image is an image from which the object image OP1 has been removed. The second projection device 2 transmits the processed image, the second transmitted image, to the first projection device 1 as an image SP21. This state is shown as image SP21 in FIG. 7.

[0094] The first projection device 1 receives the image SP21 as the first received image. The first projection device 1 projects the first received image onto the first projection target OB1 using the first projection unit 110. As a result, the object OB12 and the object image OP2 are visually recognized on the first projection target OB1. This visual recognition state is shown in the middle part of ST1 in FIG. 7, where the actual object OB12 and the object image OP2, which is a projected image of the object OB22, are visually recognized.

[0095] Here, an example is shown in which a user of the first projection device 1 writes a handwritten figure OB13 on a plane OB11. On the first projection target OB1, the handwritten figure OB13 is visually recognized in addition to an object OB12 and an object image OP2. This visual recognition state is shown in the lower part of ST1 in FIG. 7, where the object OB12 and the handwritten figure OB13, which are real entities, and the object image OP2, which is a projected image of the object OB22, are visually recognized.

[0096] The first projection device 1 captures an image of the first projection target OB1 using the first image capture unit 115 to generate a first captured image. The first captured image includes an image of the object OB12, an image of the hand-drawn figure OB13, and an image of the object image OP2. The first projection device 1 removes, from the first captured image, an image that overlaps with the image SP21 using the first filter 123. As a result, the first projection device 1 generates a first transmission image. The first transmission image includes the object image OP1, which is the image of the object OB12, and the object image OP3, which is the image of the hand-drawn figure OB13, but does not include the object image OP2. The first projection device 1 transmits the first transmission image to the second projection device 2 as the image SP12. This state is shown as the image SP12 in FIG. 7.

[0097] The second projection device 2 receives the image SP12 as a second received image, and projects the image SP12 onto the second projection target OB2 by the second projection unit 210. As a result, the object OB22 and the object images OP1 and OP3 projected by the second projection unit 210 are visually recognized on the second projection target OB2. This visual recognition state is shown in the lower part of ST2 in Fig. 7, where the object OB22, which is an actual object, the object image OP1, which is a projected image of the object OB12, and the object image OP3, which is a projected image of the figure OB13, are visually recognized.

[0098] In this way, in the projection system 100, an image of the object OB12 and the handwritten figure OB13 placed on the first projection target OB1 is projected onto the second projection target OB2. Also, an image of the object OB22 placed on the second projection target OB2 is projected onto the first projection target OB1. Therefore, the states of the first projection target OB1 and the second projection target OB2 can be shared between the first projection device 1 and the second projection device 2.

[0099] The first transmission image transmitted from the first projection device 1 to the second projection device 2 is an image obtained by removing an image that overlaps with the first received image received by the first projection device 1 from the first captured image by the first image capturing unit 115. The second projection device 2 transmits to the first projection device 1 a second transmission image obtained by removing an image that overlaps with the second received image from the second captured image by the second image capturing unit 215. This has the advantage of maintaining good visibility of the first projection target OB1 and the second projection target OB2.

[0100] For comparison, consider the example shown in FIG. 7 , where the second projection device 2 transmits the second captured image captured by the second image capturing unit 215 to the first projection device 1 as is. In this case, when the first projection device 1 projects the second captured image transmitted by the second projection device 2 onto the first projection target OB1, the object image OP1 is projected superimposed on the object OB12. The object image OP1 does not necessarily match the object OB12 perfectly. For example, the object image OP1 included in the first captured image captured by the first image capturing unit 115 is affected by factors such as uneven brightness of the plane OB1 due to ambient light, the shadow of the object OB22 caused by ambient light, the color of the plane OB1, and the unevenness of the plane OB1. Furthermore, when the object image OP1 is projected onto the second projection target OB2 by the second projection unit 210, the second captured image captured by the second image capturing unit 215 of the projected object image OP1 is likely to differ from the actual object OB12. Therefore, when the second image captured by the second image capturing unit 215 is projected onto the first projection target OB1 by the first projection unit 110, an object image OP1 that is similar to the appearance of the object OB12 but different from the appearance of the object OB12 is projected at a position where it overlaps with the object OB12. This state can be said to be less visible to the user than when only the object OB12 is visible.

[0101] In particular, when the projection optical axis PAX of the first projection unit 110 and the imaging optical axis IAX of the first imaging unit 115 are configured to be coaxial, as shown in Figures 3 and 4, the object image OP1 and the object OB12 have a high degree of similarity in terms of position and size. Therefore, the lines constituting the object image OP1 overlap with the object OB12, causing the user to see a double image. This situation results in poor visibility for the user, and is difficult to say that the user can see comfortably.

[0102] In the projection system 100 of this embodiment, the first projection device 1 transmits a first transmission image generated in a transmission image generation process to the second projection device 2, and the second projection device 2 transmits a second transmission image, which is a processed image generated in the transmission image generation process, to the first projection device 1. This allows the first projection device 1 and the second projection device 2 to share the states of the first projection target OB1 and the second projection target OB2 with good visibility.

[0103] [1-5. Operation of the embodiment] As described above, the projection system 100 described in the embodiment includes the first projection device 1 and the second projection device 2. The first projection device 1 includes the first communication unit 142 that communicates with the second projection device 2 to receive a first received image, the first projection unit 110 that projects the first received image onto the first projection target OB1, and the first capturing unit 115 that captures an area including the first projection target OB1. The first projection device 1 generates a first transmission image by removing an image that overlaps the first received image from the captured image captured by the first capturing unit 115, and transmits the first transmission image via the first communication unit 142. The second projection device 2 includes a second communication unit 242 that communicates with the first projection device 1 to receive the second received image, a second projection unit 210 that projects the second received image onto the second projection target OB2, and a second capture unit 215 that captures an area including the second projection target OB2. The second projection device 2 generates a second transmission image by removing an image that overlaps the second received image from the captured image captured by the second capture unit 215, and transmits the second transmission image via the second communication unit 242.

[0104] In a control method for the projection system 100, the first projection device 1 communicates with the second projection device 2 to receive a first received image, projects the first received image onto the first projection target OB1, and captures an area including the first projection target OB1. The first projection device 1 also generates a first transmitted image by removing an image that overlaps with the first received image from a first captured image of the first projection target OB1, and transmits the first transmitted image to the second projection device 2. The second projection device 2 also communicates with the first projection device 1 to receive a second received image, projects the second received image onto the second projection target OB2, and captures an area including the second projection target OB2. The second projection device 2 also generates a second transmitted image by removing an image that overlaps with the second received image from a second captured image of the second projection target OB2, and transmits the second transmitted image to the first projection device 1.

[0105] According to the projection system 100 and the control method for the projection system 100, the state of the first projection target OB1 and the state of the second projection target OB2 can be shared between the first projection device 1 and the second projection device 2. Furthermore, it is possible to prevent a situation in which the projection image projected by the first projection device 1 onto the first projection target OB1 and the actual first projection target OB1 overlap unnaturally. Similarly, it is possible to prevent a situation in which the projection image projected by the second projection device 2 onto the second projection target OB2 and the actual second projection target OB2 overlap unnaturally. This allows the user to view the first projection target OB1 and the second projection target OB2 with good visibility.

[0106] The first projection device 1 generates the first transmission image by removing, using the first filter 123, an image that overlaps with the first received image from the captured image of the first image capturing unit 115. This makes it possible to prevent the projection image projected by the second projection device 2 onto the second projection target OB2 from unnaturally overlapping with the actual second projection target OB2 through processing that uses the first filter 123.

[0107] The second projection device 2 generates a second transmission image by removing, using the second filter 223, an image that overlaps with the second received image from the captured image of the second image capturing unit 215. This makes it possible to prevent the projection image projected by the first projection device 1 onto the first projection target OB1 from unnaturally overlapping with the actual first projection target OB1 through processing that uses the second filter 223.

[0108] The first projection unit 110 includes an image light forming unit 111 that forms image light and a projection optical system 112 that projects the image light toward the first projection target OB1, and the first photographing unit 115 includes an imaging device 171 that receives light incident through the projection optical system. The first photographing unit 115 can also be configured to include a light receiving and emitting device 18. This allows the first projection device 1 to be configured such that the projection optical axis PAX of the image light PL1 and the optical axis AX of the first projection device 1 of the first capturing unit 115 overlap with each other. With this configuration, the first capturing unit 115 can obtain a captured image that has little deviation from the projection image PP1 projected by the first projection unit 110.

[0109] [2. Second Embodiment] FIG. 8 is a diagram showing a schematic configuration of a projection system 100A of the second embodiment. FIG. 9 is a block diagram of each device of the projection system 100A of the second embodiment. FIG. 10 is a flowchart showing the operation of a second projection device 2A of the second embodiment. FIG. 11 is a schematic diagram showing the operation of the projection system 100A of the second embodiment. The second embodiment will be described with reference to these figures. In the description of the second embodiment, components of the projection system 100A that are common to the first embodiment will be assigned the same reference numerals, and description thereof will be omitted.

[0110] 8 includes a first projection device 1, a second projection device 2A, and a third projection device 3. The first projection device 1, the second projection device 2A, and the third projection device 3 are connected to each other via a communication network N so as to be able to communicate data with each other.

[0111] There are no restrictions on the installation locations of the first projection device 1, the second projection device 2A, and the third projection device 3. For example, the use location S1 of the first projection device 1, the use location S2 of the second projection device 2A, and the use location S3 of the third projection device 3 may be located far from each other or close to each other.

[0112] The second projection device 2A has a common configuration with the second projection device 2 described in the first embodiment. In the second embodiment, an object OB22 and an object OB23 are placed on the second projection target OB2.

[0113] The third projection device 3 is a projection device configured similarly to the first projection device 1. The third projection device 3 projects image light PL3 ​​toward the third projection target OB3, and forms a projection image PP3 on the third projection target OB3. Projecting the image light PL3 ​​by the third projection device 3 corresponds to displaying the projection image PP3 on the third projection target OB3.

[0114] 8 shows a configuration in which the third projection device 3 is installed above the third projection target OB3 and projects image light PL3 ​​downward from the third projection device 3, but this is just one example. The installation state of the third projection device 3 and the configuration of the third projection target OB3 can be changed as desired, similar to the installation state of the first projection device 1 and the configuration of the first projection target OB1 described in the first embodiment.

[0115] The third projection device 3 has a function of capturing an image of the third projection target OB3. The third projection device 3 transmits a third captured image of the third projection target OB3 as a third transmitted image to the second projection device 2A via the communication network N. The third projection device 3 also receives an image from the second projection device 2A as a third received image.

[0116] The second projection device 2A has a function of capturing an image of the second projection target OB2. The second projection device 2A transmits a second captured image of the second projection target OB2 to the first projection device 1 as a second transmitted image and to the third projection device 3 as a fourth transmitted image via the communication network N. The second projection device 2A receives the image from the first projection device 1 as a second received image and receives the image from the third projection device 3 as a fourth received image.

[0117] 9, the second projection device 2A differs from the second projection device 2 in that the second control unit 220 includes a resolution conversion unit 224 and performs processing using the resolution conversion unit 224. Regarding the second projection device 2A, descriptions of components common to the second projection device 2 and operations common to the second projection device 2 will be omitted.

[0118] The third projection device 3 includes a third projection section 310 that projects image light PL3, and a drive circuit 313 that drives the third projection section 310. The third projection section 310 includes an image light formation section 311 and a projection optical system 312.

[0119] The image light forming section 311 generates the image light PL3. The image light forming section 311 includes a self-emitting element that emits light of a predetermined color. Examples of the self-emitting element include an LED element or an OLED element.

[0120] The image light forming unit 311 may include, for example, a light source having a lamp or a solid-state light source, and a light modulation device that modulates the light emitted by the light source. Examples of the lamp include a halogen lamp, a xenon lamp, and an ultra-high pressure mercury lamp. Examples of the solid-state light source include an LED and a laser light source. Examples of the light modulation device include a transmissive liquid crystal panel, a reflective liquid crystal panel, and a digital micromirror device.

[0121] The projection optical system 312 includes optical elements that guide the image light PL3 ​​emitted by the image light formation unit 311 toward the third projection target OB3. The optical elements include a lens group including one lens or multiple lenses. The optical elements may also include a prism and a dichroic mirror.

[0122] The drive circuit 313 is connected to an image processing unit 343, which will be described later. The drive circuit 313 forms the image light PL3 ​​by driving the image light formation unit 311 based on an image signal input from the image processing unit 343. For example, the drive circuit 313 forms an image by the image light formation unit 311 on a frame-by-frame basis.

[0123] The third projection device 3 includes a third image capturing unit 315. The third image capturing unit 315 is a digital camera having an image capturing element. The third image capturing unit 315 captures images under the control of a third control unit 320, which will be described later, and outputs the captured image to the third control unit 320. The image capturing range of the third image capturing unit 315 includes the direction in which the third projection unit 310 projects the image light PL3. For example, the image capturing range of the third image capturing unit 315 includes the third projection target OB3. The image capturing element included in the third image capturing unit 315 is, for example, a CMOS image sensor or a CCD image sensor.

[0124] The configurations of the image light forming unit 311, the projection optical system 312, the drive circuit 313, and the third photographing unit 315 can be the same as the configurations of the image light forming unit 111, the projection optical system 112, the drive circuit 113, and the first photographing unit 115 that are provided in the first projection device 1, respectively.

[0125] The third projection device 3 includes a third control unit 320, an operation unit 331, a remote control light receiving unit 332, an input interface 333, a connection unit 341, a third communication unit 342, and an image processing unit 343. The third control unit 320, the input interface 333, the connection unit 341, the third communication unit 342, and the image processing unit 343 are connected to each other via a bus 339 so as to be able to communicate data with each other.

[0126] The operation unit 331 includes various buttons and switches provided on the surface of the housing of the third projection device 3. The operation unit 331 generates operation signals corresponding to the operation of the buttons or switches, and outputs the operation signals to the input interface 333. The input interface 333 includes a circuit that outputs the operation signals input from the operation unit 331 to the third control unit 320.

[0127] The remote control light receiving unit 332 includes a light receiving element that receives infrared light, and receives an infrared signal transmitted from the remote control 43. When a switch (not shown) provided on the remote control 43 is operated, the remote control 43 transmits an infrared signal indicating the operation. The remote control light receiving unit 332 decodes the received infrared signal to generate an operation signal. The remote control light receiving unit 332 outputs the generated operation signal to the input interface 333. The input interface 333 includes a circuit that outputs the operation signal input from the remote control light receiving unit 332 to the third control unit 320.

[0128] There are no limitations on the specific manner in which signals are transmitted and received between the remote control 43 and the remote control light receiving unit 332. The configuration in which the remote control 43 transmits an infrared signal to the remote control light receiving unit 332 is one example. For example, the remote control 43 and the remote control light receiving unit 332 may transmit and receive signals by performing short-range wireless communication such as Bluetooth.

[0129] The connection unit 341 is an interface device that receives images from an external device, and is connected to, for example, a player that plays back an optical disc type recording medium or a personal computer.

[0130] The third communication unit 342 is connected to the communication network N and transmits and receives data to and from the second projection device 2A via the communication network N. The third communication unit 342 is, for example, a communication device including a connector for connecting a communication cable and a communication circuit for inputting and outputting signals via the communication cable. Alternatively, the third communication unit 342 may be a wireless communication device. In this case, the third communication unit 342 includes, for example, an antenna, an RF circuit, a baseband circuit, etc.

[0131] The image processing unit 343 selects an image source under the control of the third control unit 320. Sources available to the third projection device 3 include, for example, image data received by the connection unit 341 and image data received by the third communication unit 342.

[0132] The image processing unit 343 performs image processing on the image of the selected source under the control of the third control unit 320. The image processing performed by the image processing unit 343 includes, for example, resolution conversion processing, geometric correction processing, digital zoom processing, and image correction processing for adjusting the color tone and brightness of the image.

[0133] The image processing unit 343 generates an image signal based on the image after image processing and outputs it to the drive circuit 313. A frame memory (not shown) may be connected to the image processing unit 343. In this case, the image processing unit 343 loads image data acquired from a source into the frame memory. The image processing unit 343 performs image processing on the image data loaded into the frame memory.

[0134] The image processing unit 343 can be configured, for example, by an integrated circuit. The integrated circuit is configured, for example, by an LSI. More specifically, the image processing unit 343 is configured by an ASIC, a PLD, or the like. The PLD includes, for example, an FPGA. Furthermore, an analog circuit may be included as part of the configuration of the integrated circuit, or the integrated circuit may be a combination of a processor and an integrated circuit. Examples of the combination of a processor and an integrated circuit include a microcontroller, an SoC, a system LSI, and a chipset.

[0135] The configurations of the operation unit 331, the remote control light receiving unit 332, and the input interface 333 can be the same as those of the operation unit 131, the remote control light receiving unit 132, and the input interface 133, respectively. Similarly, the configurations of the connection unit 341, the third communication unit 342, and the image processing unit 343 can be the same as those of the connection unit 141, the first communication unit 142, and the image processing unit 143, respectively.

[0136] The third projection unit 310 and the third image capturing unit 315 included in the third projection device 3 can have the configurations shown in FIG. 3 and FIG. 4. That is, the image light formation unit 311 included in the third projection unit 310 can have the light emitting device 161, the projection optical system 312 can include the separation optical element 151 and the projection lens 152, and the third image capturing unit 315 can have the image capturing device 171. Similarly, the configuration shown in FIG. 4 can be applied to the third projection unit 310 and the third image capturing unit 315. In this case, the third projection unit 310 and the third image capturing unit 315 can have the light receiving and emitting device 18 and the projection lens 152 shown in FIG. 4. In this case, the first projection device 1, the second projection device 2A, and the third projection device 3 that make up the projection system 100A function as projection devices that perform projection and image capturing on the same axis.

[0137] The third control unit 320 includes a processor 321 and a memory 325. The memory 325 is a storage device that stores programs and data executed by the processor 321 in a nonvolatile manner. The memory 325 is configured from a magnetic storage device, a semiconductor storage element such as a flash ROM, or other types of nonvolatile storage device. The memory 325 may include a RAM that configures the work area of ​​the processor 321. The memory 325 stores data processed by the processor 321 and a control program 326 executed by the processor 321.

[0138] The processor 321 is configured with a CPU, an MPU, or the like. The processor 321 may be configured with a single processor, or multiple processors may function as the processor 321. The processor 321 may be configured as an SoC integrated with part or all of the memory 325 and / or other circuits. As described above, the processor 321 may be configured by combining a CPU that executes programs and a DSP that executes predetermined arithmetic processing. All of the functions of the processor 321 may be implemented in hardware, or may be configured using a programmable device. The processor 321 may also have the functions of the image processing unit 343. In other words, the functions of the image processing unit 343 may be executed by the processor 321.

[0139] The processor 321 controls each part of the third projection device 3 by executing a control program 326 stored in the memory 325. The processor 321 has a projection control unit 322 and a third filter 323. These are functional parts that are realized by the processor 321 executing the control program 326 through cooperation between hardware and software.

[0140] The projection control unit 322 receives the image transmitted by the second projection device 2 via the third communication unit 342. The image received by the third communication unit 342 from the second projection device 2 is referred to as the third received image. The projection control unit 322 projects an image based on the third received image onto the third projection target OB3 via the third projection unit 310. The projection control unit 322 then causes the third imaging unit 315 to capture an image of an area including the third projection target OB3, thereby acquiring a third captured image. The projection control unit 322 then filters the third captured image using the third filter 323, and transmits the third transmission image generated by the filtering to the second projection device 2A via the third communication unit 342. The image captured by the third projection device 3 is referred to as the third captured image, and the image generated by the third projection device 3 through filtering of the third captured image is referred to as the third transmission image. The third transmission image is also an image that the third projection device 3 transmits to the second projection device 2A.

[0141] The third filter 323 filters the third captured image based on the third received image. Specifically, the third filter 323 performs processing to remove from the third captured image any image that overlaps with the third received image.

[0142] In the projection system 100A, the first projection device 1 operates in the same manner as in the first embodiment, thereby sharing the states of the first projection target OB1 and the second projection target OB2 with the second projection device 2A. The third projection device 3 operates in the same manner as the first projection device 1. The third projection device 3 shares the states of the second projection target OB2 and the third projection target OB3 with the second projection device 2A. The second projection device 2A provides two regions on the second projection target OB2 in order to share images with both the first projection device 1 and the third projection device 3.

[0143] As shown in FIG. 8, the second projection device 2A provides a first area AR1 and a second area AR2 on the second projection target OB2. Specifically, the second projection device 2A divides the projected image PP2 into the first area AR1 and the second area AR2, and places a different image in each area. Therefore, different images are projected onto the portion of the second projection target OB2 corresponding to the first area AR1 and the portion corresponding to the second area AR2. The object OB23 is located in the first area AR1, and the object OB22 is located in the second area AR2. The first area AR1 and the second area AR2 are virtual areas, and there is no need to provide an actual partition on the second projection target OB2 to separate the first area AR1 and the second area AR2.

[0144] The projection control unit 222 of the second projection device 2A receives the second received image from the first projection device 1 via the second communication unit 242. The projection control unit 222 projects an image based on the second received image onto the second projection target OB2 via the second projection unit 210. The projection control unit 222 receives an image transmitted by the third projection device 3 via the second communication unit 242. The image received from the third projection device 3 by the second communication unit 242 of the second projection device 2A is referred to as a fourth received image. The projection control unit 222 projects an image based on the fourth received image onto the second projection target OB2 via the second projection unit 210.

[0145] Here, the projection control unit 222 projects the second received image onto the first area AR1, and projects the fourth received image onto the second area AR2. Because the first area AR1 is smaller than the entire projection image of the second projection unit 210, the projection control unit 222 performs processing to convert the resolution of the second received image using the resolution conversion unit 224. The resolution conversion unit 224 converts the resolution of the second received image into a resolution for projection. The projection resolution of the second received image is the projection resolution of the second projection unit 210 that corresponds to the first area AR1. The projection resolution can be calculated, for example, from the ratio of the first area AR1 to the entire projection area of ​​the second projection unit 210.

[0146] Furthermore, the projection control unit 222 performs processing to convert the resolution of the fourth received image using the resolution conversion unit 224. The resolution conversion unit 224 converts the resolution of the fourth received image into a resolution for projection. The projection resolution of the fourth received image is the projection resolution of the second projection unit 210 corresponding to the second area AR2. The projection resolution can be calculated, for example, from the ratio of the second area AR2 to the entire projection area of ​​the second projection unit 210.

[0147] The projection control unit 222 causes the second imaging unit 215 to capture an image of an area including the second projection target OB2, and acquires a second captured image. The projection control unit 222 divides the second captured image into an image of an area corresponding to the first area AR1 and an image of an area corresponding to the second area AR2.

[0148] The projection control unit 222 generates a first processed image by performing filtering using the second filter 223 on the captured image in the range corresponding to the first area AR1. Here, the second filter 223 performs filtering based on the second received image to remove images that overlap with the second received image from the captured image in the range corresponding to the first area AR1. Furthermore, the projection control unit 222 causes the resolution conversion unit 224 to perform processing to convert the resolution of the first processed image so that the resolution of the first processed image corresponds to the projection resolution of the first projection device 1. The projection control unit 222 transmits the first processed image after the resolution conversion processing to the first projection device 1 as a second transmitted image.

[0149] The projection control unit 222 generates a second processed image by filtering the captured image in the range corresponding to the second area AR2 using the second filter 223. Here, the second filter 223 performs filtering based on the second received image to remove images that overlap with the second received image from the captured image in the range corresponding to the second area AR2. Furthermore, the projection control unit 222 causes the resolution conversion unit 224 to perform processing to convert the resolution of the second processed image so that the resolution of the second processed image corresponds to the projection resolution of the third projection device 3. The projection control unit 222 transmits the second processed image after the resolution conversion processing to the third projection device 3 as a fourth transmitted image. The image generated by the second projection device 2A by filtering the second captured image is called the fourth transmitted image. The fourth transmitted image is also the image transmitted by the second projection device 2A to the third projection device 3.

[0150] Next, the operation of the projection system 100A in the second embodiment will be described. In the second embodiment, the operation of the first projection device 1 is the same as that described in the first embodiment. Furthermore, the operation of the third projection device 3 is the same as that of the first projection device 1 described in the first embodiment. Therefore, the operation of the second projection device 2A will be described here according to the flowchart in FIG.

[0151] The processing of steps SB31 to SB48 in FIG. 10 is executed by the second control unit 220 of the second projection device 2A. In step SB31, the second projection device 2A receives an image via the second communication unit 242. In step SB32, the second projection device 2A determines whether the sender of the received image corresponds to the first area AR1. That is, the second projection device 2A determines whether the sender of the image received in step SB31 is the first projection device 1 or the third projection device 3.

[0152] If the second projection device 2A determines that the image transmission source is the first projection device 1, that is, if it determines that the image transmission source corresponds to the first area AR1 (step SB32; YES), the second projection device 2A proceeds to step SB33. In this case, the image received in step SB31 is the second received image received from the first projection device 1. In step SB33, the second projection device 2A converts the resolution of the second received image using the resolution conversion unit 224. In step SB34, the second projection device 2A projects the second received image, whose resolution has been converted by the resolution conversion unit 224, onto the first area AR1 of the second projection target OB2 using the second projection unit 210. In step SB34, if the second projection unit 210 is currently projecting an image, the second projection device 2A updates the projection image of the second projection unit 210 based on the second received image that has been subjected to the resolution conversion process.

[0153] If the second projection device 2A determines that the image transmission source is the third projection device 3, that is, if it determines that the transmission source does not correspond to the first area AR1 (step SB32; NO), the second projection device 2A proceeds to step SB35. In this case, the image received in step SB31 is the fourth received image received from the third projection device 3. In step SB35, the second projection device 2A converts the resolution of the fourth received image using the resolution conversion unit 224. In step SB36, the second projection device 2A projects the fourth received image, whose resolution has been converted by the resolution conversion unit 224, onto the second area AR2 of the second projection target OB2 using the second projection unit 210. In step SB36, if the second projection unit 210 is currently projecting an image, the second projection device 2A updates the projection image of the second projection unit 210 based on the fourth received image that has been subjected to resolution conversion.

[0154] In step SB37, the second projection device 2A performs imaging using the second imaging unit 215 and acquires a second captured image in step SB38. In step SB39, the second projection device 2A divides the second captured image into a captured image of a range corresponding to the first area AR1 and a captured image of a range corresponding to the second area AR2. In step SB40, the second projection device 2A performs resolution conversion processing on each image divided in step SB39 using the resolution conversion unit 224. For example, in step SB40, the second projection device 2A adjusts the resolution of the captured image of the range corresponding to the first area AR1 to the resolution of the second received image using the resolution conversion unit 224. Also, for example, in step SB40, the second projection device 2A adjusts the resolution of the captured image of the range corresponding to the second area AR2 to the resolution of the fourth received image using the resolution conversion unit 224.

[0155] In step SB41, the second projection device 2A acquires a captured image of a range corresponding to the resolution-converted first area AR1. In step SB42, the second projection device 2A acquires a second received image. Specifically, the second projection device 2A acquires the last second received image received from the first projection device 1 before step SB42.

[0156] In step SB43, the second projection device 2A generates a first processed image by performing filtering on the second received image using the second filter 223. In detail, the second projection device 2A removes, from the captured image acquired in step SB41, an image that overlaps with an image included in the second received image.

[0157] In step SB44, the second projection device 2A acquires a captured image of the range corresponding to the resolution-converted second area AR2. In step SB45, the second projection device 2A acquires a fourth received image. Specifically, the second projection device 2A acquires the fourth received image, which was the last image received from the third projection device 3 before step SB45.

[0158] In step SB46, the second projection device 2A generates a second processed image by performing filtering on the fourth received image using the second filter 223. In detail, the second projection device 2A removes, from the captured image acquired in step SB44, an image that overlaps with an image included in the fourth received image.

[0159] In step SB47, the second projection device 2A transmits the first processed image as a second transmission image to the first projection device 1, and transmits the second processed image as a fourth transmission image to the third projection device 3, via the second communication unit 242.

[0160] In step SB48, the second projection device 2A determines whether to end its operation. If the second projection device 2A determines to end its operation (step SB48; YES), such as when an operation instructing to end its operation is detected via the input interface 233, the second projection device 2A ends this process. If the second projection device 2A determines not to end its operation (step SB48; NO), the second projection device 2A returns to step SB31.

[0161] 11 shows the visibility of the first projection device 1 and the second projection device 2A as an operating state of the projection system 100A. The visibility of the third projection device 3 is the same as that of the first projection device 1, so it is not shown in the figure.

[0162] Figure 11 shows the viewing state ST11 of the first projection target OB1 of the first projection device 1, the viewing state ST21 of the second projection target OB2 of the second projection device 2A, and images transmitted and received between the first projection device 1 and the second projection device 2A.

[0163] As shown in FIG. 8, an object OB12 is placed on a plane OB11 of the first projection target OB1. This visual state is shown in the upper part of ST11 in FIG. 11, and the actual object OB12 is visually recognized. Paper or the like is placed on the plane OB11, and a user using the first projection device 1 can write characters or figures on the plane OB1 with a writing implement. Furthermore, objects OB22 and OB23 are placed on a plane OB21 of the second projection target OB2. This state is not shown in FIG. 11. Paper or the like is also placed on the plane OB21, similar to the plane OB11, and a user using the second projection device 2A can write characters or figures on the plane OB21 with a writing implement. The object OB23 is located in the first area AR1, and the object OB22 is located in the second area AR2.

[0164] The first projection device 1 generates a first transmission image by filtering a first captured image of the first projection target OB1 using the first image capturing unit 115 with the first filter 123. The first projection device 1 transmits the first transmission image to the second projection device 2A as an image SP11. This state is shown as image SP11 in FIG. 11.

[0165] The second projection device 2A receives the image SP11 as the second received image. The second projection device 2A converts the resolution of the second received image. The second projection device 2A projects the second received image after the resolution conversion process onto the first area AR1. At this time, the object OB22 is present in the first area AR1, and the object image OP1 is projected. This visual state is shown in the upper part of ST2 in FIG. 11, where the actual object OB23 and the object image OP1, which is a projected image of the object OB12, are visually recognized in the first area AR1, and the actual object OB22 is visually recognized in the second area AR2.

[0166] The second projection device 2A captures an image of the second projection target OB2 using the second image capture unit 215 to generate a second captured image. The second captured image shows the state of the first area AR1 and the state of the second area AR2. The second projection device 2A divides the second captured image. The second projection device 2A generates a first processed image by filtering the captured image of the range corresponding to the first area AR1 based on the image SP11, which is the first transmission image. Furthermore, the second projection device 2A converts the resolution of the first processed image using the resolution conversion unit 224 to generate a first processed image having a resolution corresponding to the projection resolution of the first projection device 1, and transmits it as the second transmission image. The second projection device 2A transmits the first processed image to the first projection device 1 as image SP31. This state is shown as image SP31 in FIG. 11.

[0167] The first projection device 1 receives the image SP31 as the first received image and projects it onto the first projection target OB1 using the first projection unit 110. As a result, the object OB12 and the object image OP2 are visually recognized on the first projection target OB1. This visual recognition state is shown in the middle part of ST1 in FIG. 11, where the object OB12, which is a real object, and the object image OP2, which is a projected image of the object OB23, are visually recognized.

[0168] Here, an example is shown in which a user of the first projection device 1 writes a handwritten figure OB13 on a plane OB11. On the first projection target OB1, the handwritten figure OB13 is visually recognized in addition to an object OB12 and an object image OP2. This visual recognition state is shown in the lower part of ST11 in FIG. 11, in which the object OB12 and the handwritten figure OB13, which are real entities, and the object image OP2, which is a projected image of the object OB22, are visually recognized.

[0169] The first projection device 1 generates an image SP12, which is a first transmission image, by filtering a first captured image of the first projection target OB1 captured by the first capturing unit 115 based on an image SP31, which is a first received image. The image SP12 includes an object image OP1, which is an image of the object OB12, and an object image OP3, which is an image of the handwritten figure OB13, but does not include an object image OP2. The first projection device 1 transmits the image SP12 to the second projection device 2A as a first transmission image. This state is shown as image SP12 in FIG. 11.

[0170] The second projection device 2A receives the image SP12 as a second received image. The second projection device 2A converts the resolution of the second received image. The second projection device 2A projects the second received image after the resolution conversion process onto the first area AR1. As a result, the object OB22 and the object images OP1 and OP3 projected by the second projection unit 210 are visually recognized in the first area AR1 of the second projection target OB2. This visual recognition state is shown in the lower part of ST2 in FIG. 11, where the actual object OB22, the object image OP1 which is a projected image of the object OB12, and the object image OP3 which is a projected image of the figure OB13 are visually recognized in the first area AR1, and the actual object OB22 is visually recognized in the second area AR2.

[0171] In this way, in the projection system 100A, an image of the object OB12 and the handwritten figure OB13 placed on the first projection target OB1 is projected onto the second projection target OB2. Also, an image of the object OB23 placed on the second projection target OB2 is projected onto the first projection target OB1. Therefore, the states of the first projection target OB1 and the second projection target OB2 can be shared between the first projection device 1 and the second projection device 2A.

[0172] As described with reference to Fig. 10, the second projection device 2A also performs the operation shown in Fig. 11 on the third projection device 3. As a result, an image of the object OB32 placed on the third projection target OB3 is projected onto the second area AR2 of the second projection target OB2. Furthermore, an image of the object OB22 placed in the second area AR2 of the second projection target OB2 is projected onto the third projection target OB3. Therefore, the states of the second projection target OB2 and the third projection target OB3 can be shared between the second projection device 2A and the third projection device 3.

[0173] Therefore, the projection system 100A allows the status of the projection target to be shared between the first projection device 1 and the second projection device 2A, and between the third projection device 3 and the second projection device 2A. The second projection device 2A shares the status of the first area AR1 of the second projection target OB2 with the first projection device 1, and shares the status of the second area AR2 with the third projection device 3. Therefore, a user of the second projection device 2A can share the status of the projection area while distinguishing between the status of the first projection device 1 and the status of the third projection device 3.

[0174] The second projection device 2A then performs resolution conversion processing on the second received image received from the first projection device 1 and the fourth received image received from the third projection device 3. Therefore, the second projection device 2A can share images with both the first projection device 1 and the third projection device 3 by utilizing the second projection target OB2, which has a limited area.

[0175] Furthermore, the second projection device 2A divides the second captured image and performs resolution conversion processing on the captured image in the range corresponding to the first area AR1 and the captured image in the range corresponding to the second area AR2. This allows the process of removing images that overlap with the second received image from the captured image and the process of removing images that overlap with the second received image from the captured image to be quickly performed. Furthermore, the first processed image has a resolution corresponding to the projection resolution of the first projection device 1, and the second processed image has a resolution corresponding to the projection resolution of the third projection device 3. This allows images to be shared with both the first projection device 1 and the third projection device 3 without increasing the processing load on the first projection device 1 and the third projection device 3.

[0176] As described above, the projection system 100A of the second embodiment includes the third projection device 3. The third projection device 3 includes a third communication unit 342 that communicates with the second projection device 2A to receive a third received image, a third projection unit 310 that projects the third received image onto the third projection target OB3, and a third capture unit 315 that captures an area including the third projection target OB3. The third projection device 3 generates a third transmitted image by removing an image that overlaps with the third received image from the third captured image captured by the third capture unit 315, and transmits the third transmitted image via the third communication unit 342. The second projection device 2A receives a fourth received image from the third projection device 3 via the second communication unit 242, and projects the second received image onto the first area AR1 of the second projection target and the fourth received image onto the second area AR2 of the second projection target via the second projection unit. The second projection device 2A generates a second transmitted image including a first processed image and a second processed image. The second projection device 2A generates the first processed image by removing an image that overlaps with the second received image from the captured image in the range corresponding to the first area AR1 of the second captured image, and transmits the first processed image to the first projection device 1. The second projection device 2A generates a second processed image by removing an image that overlaps with the fourth received image from the captured image in the range corresponding to the second area AR2 of the second captured image, and transmits the second processed image to the third projection device 3.

[0177] This allows the projection system 100A to share the state of the first projection target OB1 and the state of the second projection target OB2 between the first projection device 1 and the second projection device 2A. Furthermore, the projection system 100A allows the state of the second projection target OB2 and the state of the third projection target OB3 to be shared between the second projection device 2A and the third projection device 3. The projection system 100A can prevent the projection image projected by the first projection device 1 onto the first projection target OB1 from unnaturally overlapping with the actual first projection target OB1. Similarly, it can prevent the projection image projected by the second projection device 2 onto the second projection target OB2 from unnaturally overlapping with the actual second projection target OB2. Furthermore, it is possible to prevent the projection image projected by the third projection device 3 onto the third projection target OB3 from unnaturally overlapping with the actual third projection target OB3, thereby allowing the user to view the first projection target OB1, the second projection target OB2, and the third projection target OB3 with good visibility.

[0178] In the projection system 100A, the third projection device 3 generates a third transmitted image by removing an image that overlaps with the third received image from the third captured image using the third filter 323. This process using the third filter 323 makes it possible to prevent the projection image projected by the second projection device 2A onto the second area AR2 from unnaturally overlapping with the actual object in the second area AR2.

[0179] The second projection device 2A includes a second filter 223 that removes an image that overlaps with the second received image from the second captured image. The second projection device 2A generates a first processed image by using the second filter 223 to remove an image that overlaps with the second received image from an image in a range of the second captured image that corresponds to the first area AR1. The second projection device 2A generates a second processed image by using the second filter 223 to remove an image that overlaps with the fourth received image from an image in a range of the second captured image that corresponds to the second area AR2. This allows the second projection device 2A to share images with both the first projection device 1 and the third projection device 3 using the second projection target OB2.

[0180] The second projection device 2A is configured to be able to perform resolution conversion processing. The second projection device 2A transmits a first processed image having a resolution corresponding to the second received image to the first projection device 1, and transmits a second processed image having a resolution corresponding to the fourth received image to the third projection device 3. As a result, the second projection device 2A transmits a first processed image having a resolution that the first projection device 1 can process to the first projection device 1, and transmits a second processed image having a resolution that the third projection device 3 can process to the third projection device 3. Therefore, the second projection device 2A can share images with the first projection device 1 and the third projection device 3 without increasing the processing load on the first projection device 1 and the third projection device 3.

[0181] 3. Other Embodiments The above-described embodiments are preferred embodiments of the present invention, but the present invention is not limited to these and various modifications are possible within the scope of the present invention.

[0182] 3 and 4 are merely examples, and the configurations of the first projection unit 110 and the first image capturing unit 115 provided in the first projection device 1 can be changed as desired. For example, the first image capturing unit 115 may be configured as a separate entity from the first projection device 1. The second projection unit 210 and the second image capturing unit 215 provided in the second projection device 2, 2A have the same configuration. The third projection unit 310 and the third image capturing unit 315 have the same configuration.

[0183] The configurations of the devices shown in Figures 2 and 9 indicate functional configurations, and the specific implementation form is not particularly limited. In other words, it is not necessary to implement hardware corresponding to each functional unit individually, and it is of course possible to implement a configuration in which a single processor executes a program to realize the functions of multiple functional units. Furthermore, some of the functions realized by software in the above embodiments and modifications may be realized by hardware, and some of the functions realized by hardware may be realized by software.

[0184] Furthermore, the processing units in the sequence diagram shown in Fig. 5 and the flowcharts in Fig. 6 and Fig. 10 are divided according to the main processing content in order to make it easier to understand the operation of each device in projection systems 100 and 100A. The method of dividing the processing units and the names shown in these figures do not limit the present invention. The processing executed by each device can be divided into more processing units depending on the processing content, or one processing unit can be divided so that it includes even more processes.

[0185] The control program 126 may be recorded on a recording medium that is readable by the first projection device 1, for example. The recording medium may be a magnetic or optical recording medium or a semiconductor memory device. Specific examples include portable or fixed recording media such as flexible disks, optical disc recording media, magneto-optical disc recording media, and semiconductor storage devices. Alternatively, these programs may be stored on a server device or the like, and downloaded from the server device as needed. The same applies to the control programs 226 and 326. [Explanation of symbols]

[0186] 1...first projection device, 2, 2A...second projection device, 3...third projection device, 100, 100A...projection system, 110...first projection unit, 115...first image capturing unit, 120...first control unit, 121...processor, 122...projection control unit, 123...first filter, 125...memory, 126...control program, 142...first communication unit, 210...second projection unit, 215...second image capturing unit, 220...second control unit, 221...processor, 222...projection control control unit, 223...second filter, 224...resolution conversion unit, 225...memory, 226...control program, 242...second communication unit, 310...third projection unit, 315...third imaging unit, 320...third control unit, 321...processor, 322...projection control unit, 323...third filter, 325...memory, 326...control program, 342...third communication unit, AR1...first area, AR2...second area, N...communication network, OB1...first projection target, OB2...second projection target, OB3...third projection target.

Claims

1. A projection system including a first projection device, a second projection device, and a third projection device, the first projection device, a first communication unit that communicates with the second projection device to receive a first received image; a first projection unit that projects the first received image onto a first projection target; a first image capturing unit that captures an image of an area including the first projection target, generating a first transmission image by removing an image that overlaps the first received image from a first captured image captured by the first imaging unit, and transmitting the first transmission image by the first communication unit; the second projection device, a second communication unit that communicates with the first projection device to receive a second received image; a second projection unit that projects the second received image onto a second projection target; a second image capturing unit configured to capture an image of an area including the second projection target, generating a second transmission image by removing an image that overlaps the second received image from a second captured image captured by the second imaging unit, and transmitting the second transmission image by the second communication unit; the third projection device, a third communication unit that communicates with the second projection device to receive a third received image; a third projection unit that projects the third received image onto a third projection target; a third image capturing unit that captures an image of an area including the third projection target, generating a third transmission image by removing an image that overlaps with the third received image from a third captured image captured by the third imaging unit, and transmitting the third transmission image by the third communication unit; the second projection device, receiving a fourth received image from the third projection device by the second communication unit; projecting the second received image onto a first area of ​​the second projection target and projecting the fourth received image onto a second area of ​​the second projection target by the second projection unit; the second transmitted image includes a first processed image and a second processed image; generating the first processed image by removing an image overlapping with the second received image from an image in a range corresponding to the first region in the second captured image, and transmitting the first processed image to the first projection device; A projection system that generates the second processed image by removing an image that overlaps with the fourth received image from an image in the range corresponding to the second area of ​​the second captured image, and transmits the second processed image to the third projection device.

2. The projection system according to claim 1 , wherein the first projection device generates the first transmitted image by removing an image that overlaps with the first received image from the first captured image using a first filter.

3. 3. The projection system according to claim 1, wherein the second projection device generates the second transmitted image by removing an image that overlaps with the second received image from the second captured image using a second filter.

4. The projection system according to claim 1 , wherein the third projection device generates the third transmitted image by removing an image that overlaps with the third received image from the third captured image using a third filter.

5. the second projection device, a second filter that removes an image that overlaps with the second received image from the second captured image; generating the first processed image by removing an image overlapping with the second received image from an image in a range corresponding to the first region in the second captured image using the second filter; 5. The projection system of claim 1, wherein the second processed image is generated by using the second filter to remove images that overlap with the fourth received image from an image in a range of the second captured image corresponding to the second region.

6. the second projection device is configured to be able to perform resolution conversion processing, and transmits the first processed image having a resolution corresponding to the second received image to the first projection device; 6. The projection system according to claim 1, wherein the second processed image having a resolution corresponding to the fourth received image is transmitted to the third projection device.

7. the first projection unit includes an image light forming unit that forms image light, and a projection optical system that projects the image light toward the first projection target; The projection system according to claim 1 , wherein the first image capturing unit includes an image capturing device that receives light incident through the projection optical system.

8. A control method for a projection system including a first projection device, a second projection device, and a third projection device, comprising: The first projection device communicating with the second projection device to receive a first received image; projecting the first received image onto a first projection target; capturing an image of an area including the first projection target; generating a first transmission image by removing an image that overlaps the first reception image from a first captured image of the first projection target, and transmitting the first transmission image to the second projection device; The second projection device communicating with the first projection device to receive a second received image; projecting the second received image onto a second projection target; taking an image of an area including the second projection target; generating a second transmission image by removing an image that overlaps the second reception image from a second captured image of the second projection target, and transmitting the second transmission image to the first projection device; The third projection device communicating with the second projection device to receive a third received image; projecting the third received image onto a third projection target; Shooting an area including the third projection target; generating a third transmission image by removing an image that overlaps with the third reception image from a third captured image of the third projection target, and transmitting the third transmission image to the second projection device; The second projection device communicating with the third projection device to receive a fourth received image; projecting the second received image onto a first area of ​​the second projection target and projecting the fourth received image onto a second area of ​​the second projection target; the second transmitted image includes a first processed image and a second processed image; generating the first processed image by removing an image overlapping with the second received image from an image in a range corresponding to the first region in the second captured image, and transmitting the first processed image to the first projection device; A control method for a projection system, which generates the second processed image by removing images that overlap with the fourth received image from an image in the range corresponding to the second area of ​​the second captured image, and transmits the second processed image to the third projection device.

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