Control method for projection system and projection device

Abstract

To easily grasp a cause of abnormal execution of interactive control.SOLUTION: When receiving first identification information J1 from a first image cable CP1, a first personal computer 600 transmits the first identification information J1 to a projector 1 via a first control cable CC1. When receiving second identification information J2 from a second image cable CP2, a second personal computer 700 transmits the second identification information J2 to the projector 1 via a second control cable CC2. The projector 1 executes determining whether the identification information input from the first control terminal 171 is the first identification information J1 or the second identification information J2, and notifying a user of a first message MG1 indicating that a control cable connected to the first control terminal 171 is invalid when determining that the identification information is the second identification information J2.SELECTED DRAWING: Figure 4

Description

[Technical field]

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

[0002] 2. Description of the Related Art There is known a technology relating to so-called interactive control, which accepts a user's operation on a projection surface such as a whiteboard and projects an image corresponding to the user's operation onto the projection surface. For example, in the interactive system described in Patent Document 1, a personal computer device, which is an interactively controlled device, transmits an assigned physical address to a projector device, and other devices do not transmit physical addresses to the projector device. The projector device determines, from among the projection images input to each input terminal, a projection image for interactive control input from the personal computer device based on the received physical address. Then, when a pen operation is detected on the coordinates corresponding to the projection area of ​​the determined projection image, the projector device converts the position coordinates of the pen into operation information in the coordinate system of the personal computer device and transmits it to the personal computer device. The projector device is connected to the personal computer device via an image cable for inputting a projection image corresponding to interactive control and a control cable for transmitting and receiving operation information. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2016-21699 A Summary of the Invention [Problem to be solved by the invention]

[0004] For example, a plurality of personal computer devices may be connected to one projector device, and a desired personal computer device among the plurality of personal computer devices may be interactively controlled by the one projector device. In this case, the desired personal computer device may not be interactively controlled normally because the desired personal computer device and one projector device are not connected by a correct combination of image cable and control cable. However, it is difficult for a user to understand the reason why the desired personal computer device is not interactively controlled normally. [Means for solving the problem]

[0005] One aspect of the present disclosure is a method for controlling a projection system comprising: a projection device that projects a projection image onto a projection surface, receives a user's operation on the projection surface, and generates a control signal indicating a position of the operation on the projection surface; a first information processing device communicatively connected to the projection device and controlled based on the control signal; and a second information processing device communicatively connected to the projection device and controlled based on the control signal, wherein the first information processing device is configured to transmit a first image signal indicating the projection image to the projection device via a first image cable and receive the control signal from the projection device via a first control cable, and the second information processing device is configured to transmit a second image signal indicating the projection image to the projection device via a second image cable and receive the control signal from the projection device via the second control cable, and the projection device comprises a first control terminal to which the first control cable is connected and a second control terminal to which the second control cable is connected, a control cable for transmitting first identification information to the first information processing device via the first image cable and a control cable for transmitting second identification information to the second information processing device via the second image cable; when the first information processing device receives the first identification information, the first identification information can be transmitted to the projection device via the first control cable; and when the second information processing device receives the second identification information, the second identification information can be transmitted to the projection device via the second control cable; and when the first information processing device is connected to the projection device via the first image cable and a control cable is connected to the first control terminal, the projection device determines whether the identification information input from the first control terminal is the first identification information or the second identification information; and when it is determined that the identification information is the second identification information, notifies the projection device of a first message indicating that the control cable connected to the first control terminal is invalid.

[0006] Another aspect of the present disclosure includes a projection device that projects a projection image onto a projection surface, receives a user's operation on the projection surface, and generates a control signal indicating a position of the operation on the projection surface, a first information processing device communicatively connected to the projection device, and a second information processing device communicatively connected to the projection device, wherein the first information processing device is configured to transmit a first image signal indicating the projection image to the projection device via a first image cable, receive the control signal from the projection device via a first control cable, and be controlled based on the control signal, and the second information processing device is configured to transmit a second image signal indicating the projection image to the projection device via a second image cable, receive the control signal from the projection device via the second control cable, and be controlled based on the control signal, and the projection device is a second information processing device to which the first control cable and the second control cable are connected. A control method for a projection system having a first control terminal and a second control terminal, wherein the first information processing device is capable of transmitting first identification information to the projection device via each of the first image cable and the first control cable, and the second information processing device is capable of transmitting second identification information to the projection device via each of the second image cable and the second control cable, and the projection device includes, when the first information processing device is connected to the projection device via the first image cable and a control cable is connected to the first control terminal, determining whether the identification information input from the first control terminal is the first identification information or the second identification information, and when it is determined that the identification information is the second identification information, reporting a first message indicating that the control cable connected to the first control terminal is invalid.

[0007] Yet another aspect of the present disclosure includes a projection device that projects a projection image onto a projection surface, receives a user's operation on the projection surface, and generates a control signal indicating a position of the operation on the projection surface, a first information processing device communicatively connected to the projection device, and a second information processing device communicatively connected to the projection device, wherein the first information processing device is configured to transmit a first image signal indicating the projection image to the projection device via a first image cable, receive the control signal from the projection device via a first control cable, and be controlled based on the control signal, and the second information processing device is configured to transmit a second image signal indicating the projection image to the projection device via a second image cable, receive the control signal from the projection device via the second control cable, and be controlled based on the control signal, and the projection device is configured to transmit a second image signal indicating the projection image to the projection device via a second image cable, receive the control signal from the projection device via the second control cable, and be controlled based on the control signal, a first control terminal to which a control cable is connected and a second control terminal to which the second control cable is connected, wherein the projection device transmits first identification information via the first image cable and the first control terminal, and transmits second identification information via the second image cable and the second control terminal, respectively, and the first information processing device, when the projection device is connected to the first information processing device via the first image cable and the first control cable is connected to the first control terminal, determines whether the identification information input via the first control cable is the first identification information or the second identification information, and when it is determined that the identification information is the second identification information, notifies a first message indicating that the control cable connected to the first control terminal is invalid.

[0008] Yet another aspect of the present disclosure is a control method for a projection system comprising: a projection device that projects a projection image onto a projection surface, receives a user operation on the projection surface, and generates a control signal indicating a position of the operation on the projection surface; a first information processing device communicatively connected to the projection device; and a second information processing device communicatively connected to the projection device, wherein the first information processing device is configured to transmit a first image signal indicating the projection image to the projection device via a first image cable, receive the control signal from the projection device via a first control cable, and be controlled based on the control signal; the second information processing device is configured to transmit a second image signal indicating the projection image to the projection device via a second image cable, receive the control signal from the projection device via a second control cable, and be controlled based on the control signal; and the projection device comprises a first control terminal to which the first control cable is connected and a second control terminal to which the second control cable is connected, wherein the projection device transmits first identification information via the first control terminal, and generates a control signal indicating a position of the operation on the projection surface; the first information processing device, when receiving the first identification information, is capable of transmitting the first identification information to the projection device via the first image cable, and when receiving the second identification information, is capable of transmitting the second identification information to the projection device via the first image cable; the second information processing device, when receiving the first identification information, is capable of transmitting the first identification information to the projection device via the second image cable, and when receiving the second identification information, is capable of transmitting the second identification information to the projection device via the second image cable; the projection device is connected to the first control terminal via the first control cable and, when an image cable is connected to the projection device, determines whether the identification information input via the image cable is the first identification information or the second identification information; and, when it is determined that the identification information is the second identification information, notifies a first message indicating that the image cable connected to the projection device is unauthorized.

[0009] Another aspect of the present disclosure is a projection device that projects a projection image onto a projection surface, accepts a user operation on the projection surface, and generates a control signal indicating a position of the operation on the projection surface, the projection device being communicably connected to a first information processing device and a second information processing device, the first information processing device being configured to transmit a first image signal indicating the projection image to the projection device via a first image cable, receive the control signal from the projection device via a first control cable, and be controlled based on the control signal, and when first identification information is received from the projection device, the first information processing device being configured to transmit the first identification information to the projection device via the first control cable, the second information processing device being configured to transmit a second image signal indicating the projection image to the projection device via a second image cable, receive the control signal from the projection device via a second control cable, and be controlled based on the control signal, and when second identification information is received from the projection device, a first control terminal to which the first control cable is connected and a second control terminal to which the second control cable is connected; and a processor, the processor being capable of transmitting the first identification information to the first information processing device via the first image cable, transmitting the second identification information to the second information processing device via the second image cable, determining whether the identification information input from the first control terminal is the first identification information or the second identification information when the first information processing device is connected to the projection device via the first image cable and a control cable is connected to the first control terminal, and when it is determined that the identification information is the second identification information, reporting a first message indicating that the control cable connected to the first control terminal is invalid. [Brief description of the drawings]

[0010] [Figure 1] FIG. 1 is a perspective view showing an example of the configuration of a projector according to an embodiment. [Diagram 2]FIG. 1 is a side view showing an example of a projector according to an embodiment. [Diagram 3] FIG. 2 is a diagram showing an example of the configuration of a projector and a first indicator according to the embodiment. [Figure 4] FIG. 1 is a diagram showing an example of the configuration of a projection system according to a first embodiment. [Diagram 5] 5 is a flowchart showing an example of processing of the projection system in the first embodiment. [Figure 6] FIG. 13 is a diagram showing an example of the configuration of a projection system according to a second embodiment. [Figure 7] 10 is a flowchart showing an example of processing of a projection system in a second embodiment. [Figure 8] FIG. 13 is a diagram showing an example of the configuration of a projection system according to a third embodiment. [Figure 9] 13 is a flowchart showing an example of processing of a projection system according to a third embodiment. [Figure 10] FIG. 13 is a diagram showing an example of the configuration of a projection system according to a fourth embodiment. [Figure 11] 13 is a flowchart showing an example of processing of a projection system in a fourth embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] The present embodiment will be described below with reference to the drawings. The present embodiment includes a first embodiment described with reference to Figures 4 and 5, a second embodiment described with reference to Figures 6 and 7, a third embodiment described with reference to Figures 8 and 9, and a fourth embodiment described with reference to Figures 10 and 11. First, a configuration common to the first, second, third and fourth embodiments will be described with reference to FIGS. 1 to 3. FIG.

[0012] [1. Projector configuration] FIG. 1 is a perspective view showing an example of the configuration of a projector 1 in the present embodiment. The projector 1 includes a projector body 100, a projection surface 10, and a first pointer 50. The projection surface 10 is a surface onto which the projector body 100 projects an image. The first pointer 50 is used by a user to point to a position PS on the projection surface 10. The position PS on the projection surface 10 can also be specified by a second pointing object 70 such as the user's finger. FIG. 1 shows an X-axis, a Y-axis, and a Z-axis which are orthogonal to each other. The Z-axis indicates a direction parallel to the normal direction of the projection surface 10. The Y-axis indicates a direction parallel to the vertical direction. The X-axis indicates a direction perpendicular to each of the Z-axis and the Y-axis. Hereinafter, the positive direction of the Z-axis may be referred to as "forward". The positive direction of the Y-axis may be referred to as "downward". The positive direction of the X-axis may be referred to as "rightward".

[0013] The projector body 100 generates image light corresponding to image data and projects the generated image light onto the projection surface 10. The projector body 100 also has a so-called "interactive function." The "interactive function" is a function that detects a position PS on the projection surface 10 indicated by the first indicator 50 or the second indicator 70, displays an image corresponding to the position PS or trajectory of the first indicator 50 or the second indicator 70 on the projection surface 10 based on the detected position PS, modifies the image displayed on the projection surface 10, and controls at least one of a first personal computer 600 or a second personal computer 700 described below. The projector 1 corresponds to an example of a "projection device."

[0014] In this embodiment, the process of generating an image corresponding to the position PS or trajectory of the first indicator 50 or the second indicator 70 based on the position PS of the projection surface 10 indicated by the first indicator 50 or the second indicator 70, or making changes to the image displayed on the projection surface 10, is executed by the first personal computer 600 or the second personal computer 700. The first personal computer 600 corresponds to an example of a "first information processing device." The second personal computer 700 corresponds to an example of a "second information processing device." The first personal computer 600 and the second personal computer 700 will be described with reference to FIGS.

[0015] The first indicator 50 is a pen-shaped indicator that is held by the user and has a light-emitting tip 51, a shaft 52 that is gripped by the user, and the like. A light-emitting unit 55 such as an LED (Light Emitting Diode) that emits near-infrared light is mounted on the tip 51. The light-emitting unit 55 emits light at a predetermined light-emitting interval when the tip 51 is in contact with the projection surface 10. The light-emitting unit 55 also emits light at a predetermined light-emitting interval even when the tip 51 is not in contact with the projection surface 10. Although one first indicator 50 is shown in FIG. 1, the number of first indicators 50 that can be used simultaneously is not limited to one, and a plurality of first indicators 50 can also be used simultaneously. The first indicator 50 will be further described with reference to FIG.

[0016] Furthermore, when using the user's finger as the second indicator 70, the user touches the tip of the finger or the like to the projection surface 10 to indicate a position PS on the projection surface 10. The projector body 100 emits detection light along the projection surface 10, and when the tip of the second indicator 70 comes into contact with the projection surface 10, the detection light is blocked. This detection light is hereinafter referred to as second light 180. The second light 180 is reflected by the second indicator 70, and a portion of the reflected light of the second light 180 travels from the second indicator 70 toward the projector body 100. The projector body 100 detects the reflected light of the second light 180 reflected by the second indicator 70, and detects the position PS indicated by the second indicator 70. That is, in this embodiment, the indicators include a first indicator 50 and a second indicator 70.

[0017] FIG. 2 is a side view showing an example of the projector 1 in this embodiment. In this embodiment, the projector body 100 is fixed to a wall surface, for example, and installed in front of and above the projection surface 10. The projector body 100 projects image light toward the projection surface 10 diagonally below the projector body 100. The drawing area 20 is an area of ​​the projection surface 10 onto which the image light is projected by the projector body 100. The projector body 100 accepts drawing by a pointer in the drawing area 20. In addition, the projector body 100 irradiates second light 180 used for detecting the first pointer 50 and the second pointer 70 in a direction corresponding to the projection surface 10.

[0018] The direction in which the second light 180 is irradiated is, for example, a direction in which the reflected light reflected by the second indicator 70 approaching within a predetermined distance from the projection surface 10 can be incident on the imaging unit 135. The second light 180 is light used to detect the position PS of the second indicator 70, and is infrared light in this embodiment. Since the second light 180 is infrared light, the second indicator 70 can be detected without being affected by image light mainly composed of visible light, and does not affect the display by the image light. The second light 180 is irradiated to a range including at least a part of the projection surface 10. In this embodiment, the second light 180 is projected, for example, to a range covering the entire projection surface 10. The second light 180 is further described with reference to FIG.

[0019] [2. Configuration of the projector body and the first indicator] FIG. 3 is a diagram showing an example of the configuration of the projector body 100 and the first indicator 50 in this embodiment. First, a description will be given of the configuration of the projector main body 100. The projector main body 100 includes an image storage section 110, a projection section 120, a transmission section 131, an irradiation section 133, an imaging section 135, a light receiving section 140, and a first control section 150.

[0020] The image storage unit 110 stores an image received from the first personal computer 600 or the second personal computer 700 as an image to be projected by the projection unit 120. The image storage unit 110 is a so-called "frame memory" that stores the image to be projected by the projection unit 120 in units of frames. In the following description, the image projected by the projection unit 120 may be referred to as a "projected image."

[0021] The image storage unit 110 outputs an image signal indicating an image to the light modulation device 123 described later, and causes the light modulation device 123 to output image light corresponding to the image data. The image light generated by the light modulation device 123 is projected onto the projection surface 10 by the projection unit 120.

[0022] The projection unit 120 includes a light source 121 , a light modulation device 123 , and an optical unit 125 .

[0023] The light source 121 includes a light source such as a xenon lamp, an extra-high pressure mercury lamp, an LED, a laser light source, etc. The light source 121 may also include a reflector and an auxiliary reflector that guide the light emitted from the light source to the light modulation device 123.

[0024] The light modulation device 123 includes a modulation element such as a liquid crystal panel. The light modulation device 123 forms image light by modulating the light incident from the light source 121 in accordance with an image signal input from the image storage unit 110. The image light is typically color image light including three colors of visible light, red (R), green (G), and blue (B). In this embodiment, the light modulation device 123 is described as having a modulation element such as a liquid crystal panel, but is not limited thereto. The light modulation device 123 may be a so-called DLP (Digital Light Processing) type having a DMD (Digital Mirror Device).

[0025] The optical unit 125 projects the image light formed by the light modulation device 123 onto the projection surface 10 to form an image on the projection surface 10. The optical unit 125 includes at least one of a lens and a mirror. The optical unit 125 may include a zoom mechanism that enlarges or reduces the image projected onto the projection surface 10, and a focus adjustment mechanism that adjusts the focus.

[0026] The transmission unit 131 outputs signal light 181, which is a signal for synchronizing the light emission timing of the first indicator 50 with the imaging timing of the imaging unit 135. The signal light 181 is indicated by a two-dot chain line in Fig. 3. The signal light 181 is, for example, a near-infrared light signal that can be received by the receiving unit 53. When the projector body 100 is in an activated state, the transmission unit 131 transmits the signal light 181 at predetermined time intervals.

[0027] The signal light 181 is, for example, a signal that specifies the timing for the first indicator 50 to transmit the first light 190. The first light 190 is near-infrared light having a predetermined emission pattern. In Fig. 3, the first light 190 is indicated by a dashed dotted line. The first indicator 50 transmits the first light 190 in synchronization with the timing of receiving the signal light 181, for example. In this way, the projector body 100 can cause the imaging unit 135 to capture an image in synchronization with the timing at which the first indicator 50 emits the first light 190. The transmission unit 131 includes, for example, a light source such as an LED, and a device that controls turning the light source on and off. The device that controls turning the light source on and off can be configured, for example, by an ASIC (Application Specific Integrated Circuit), an FPGA (Field-Programmable Gate Array), or the like.

[0028] The irradiation unit 133 irradiates a second light 180 for detecting the first indicator 50 and the second indicator 70 in a direction including the projection surface 10. In FIG. 3, the second light 180 is indicated by a dashed line. The irradiation unit 133 has an LD (Laser Diode) or an LED as a light source that outputs infrared light. The irradiation unit 133 may also include an optical component that diffuses the infrared light output by the light source toward the projection surface 10.

[0029] The imaging unit 135 is a camera equipped with an imaging element such as a CMOS (Complementary Metal Oxide Semiconductor) or a CCD (Charge Coupled Device) that receives near-infrared light outputted by the light emitting unit 55 of the first indicator 50. The imaging unit 135 also includes an optical system that forms an image on the imaging element, an aperture that limits the amount of light incident on the imaging element, and the like. The imaging section 135 captures an image of a range including the projection surface 10 and generates a captured image. The imaging section 135 receives and captures the first light 190 outputted by the first indicator 50. The captured image generated by the imaging section 135 is outputted to the first control section 150.

[0030] When capturing an image, the imaging section 135 outputs an interrupt signal to the first control section 150. When the imaging section 135 receives a response corresponding to the interrupt signal from the first control section 150, the imaging section 135 outputs the captured image to the first control section 150.

[0031] The light receiving unit 140 receives an infrared signal transmitted from the remote control 5. The light receiving unit 140 generates an operation signal corresponding to the received infrared signal, and outputs the generated operation signal to the first control unit 150. The operation signal is a signal corresponding to a switch on the remote control 5 operated by the user.

[0032] The first control unit 150 is a computer device including a first memory 150B and a first processor 150A. The first memory 150B includes, for example, a volatile memory such as a random access memory (RAM) and a non-volatile memory such as a read only memory (ROM). The volatile memory constitutes a work area for the first processor 150A. The non-volatile memory stores the first control program PG1 executed by the first processor 150A and calibration data. The first control program PG1 includes firmware and application programs.

[0033] The calibration data is data that associates the captured image with the drawing area 20 of the projection surface 10. Specifically, the calibration data is data that associates the coordinates of each pixel in the coordinate system of the captured image with the coordinates of each pixel in the coordinate system of the image storage unit 110. In this embodiment, the coordinates of the captured image are referred to as "camera coordinates," and the coordinates of the image storage unit 110 are referred to as "panel coordinates." By referring to the calibration data, a corresponding position PS in the drawing area 20 is uniquely identified for one position on the captured image. In other words, the "panel coordinates" correspond to the corresponding position PS in the drawing area 20.

[0034] The first processor 150A is configured, for example, by a CPU, a MPU (Micro Processor Unit), etc. The first processor 150A executes a control program to control each part of the projector body 100. The first processor 150A may be configured by a plurality of processors.

[0035] The first control unit 150 detects the first light 190 captured in the captured image and the reflected light of the second light 180 reflected by the first indicator 50. The first control unit 150 analyzes the captured image generated by the imaging unit 135 to identify the positions PS indicated by the first indicator 50 and the second indicator 70. The first control unit 150 generates coordinate information indicating the positions of the light points of the detected first light 190 and the light points of the reflected light of the second light 180. The coordinate information is expressed in camera coordinates.

[0036] The first control unit 150 converts the coordinate information expressed in the camera coordinate system into coordinate information in the panel coordinate system. This conversion is performed, for example, based on calibration data generated by a calibration performed in advance.

[0037] The first control unit 150 controls each unit of the projector body 100 to display an image on the projection surface 10. The first control unit 150 receives a projection image from the first personal computer 600 or the second personal computer 700, and displays the projection image on the projection surface 10. Furthermore, the first control unit 150 generates a control signal indicating a position PS on the projection surface 10 indicated by the first indicator 50 and the second indicator 70, and transmits the generated control signal to the first personal computer 600 or the second personal computer 700. The position PS indicated by this control signal is the indicated position indicated on the projection surface 10, and can be said to be an operation position.

[0038] The first personal computer 600 or the second personal computer 700 receives the control signal and generates drawing data representing images, figures, characters, symbols, etc. corresponding to the trajectory of the position PS. The first personal computer 600 or the second personal computer 700 also superimposes the drawing data on the projection image. The first personal computer 600 or the second personal computer 700 then transmits to the projector body 100 a superimposed image in which the drawing data and the projection image are superimposed.

[0039] The first control unit 150 develops the superimposed image received from the first personal computer 600 or the second personal computer 700 into coordinates on the image storage unit 110. As a result, the superimposed image is displayed on the projection surface 10.

[0040] Next, the configuration of the first indicator 50 will be described. The first indicator 50 includes a tip portion 51 , a shaft portion 52 , a receiving portion 53 , a tip switch 54 , a light emitting portion 55 , a power supply portion 57 , and a second control portion 58 .

[0041] The receiving unit 53 includes a light receiving element that receives near-infrared light, and receives the signal light 181 transmitted from the projector body 100. The receiving unit 53 outputs an internal signal indicating the timing at which the signal light 181 is received, etc., to the second control unit 58.

[0042] The tip switch 54 is a switch that turns on when the tip 51 comes into contact with the projection surface 10 and is pressed down, and turns off when the contact between the tip 51 and the projection surface 10 is released.

[0043] The light-emitting unit 55 includes an LED that emits near-infrared light, and the light emission is controlled by the second control unit 58, and outputs the first light 190 that is near-infrared light.

[0044] The power supply unit 57 includes a battery such as a primary battery, a secondary battery, or a photovoltaic cell, and supplies power to each part of the first indicator 50. The first indicator 50 may include a power switch that turns on and off the supply of power from the power supply unit 57.

[0045] The second control unit 58 includes a processor such as a CPU, a storage device such as a memory, and various peripheral circuits. In other words, the second control unit 58 functions as a computer. The second control unit 58 controls each part of the first indicator 50 by the processor executing a program stored in the storage device. The second control unit 58 may also be configured to include multiple processors.

[0046] The second control unit 58 determines the light emission timing, which is the timing at which the light emitting unit 55 emits light, based on the internal signal input from the receiving unit 53. The second control unit 58 causes the light emitting unit 55 to emit light at the determined light emission timing, and outputs the first light 190.

[0047] [3. First embodiment] [3-1. Projection system configuration] Next, a projection system 2 according to the first embodiment will be described with reference to Fig. 4-Fig. 5. Fig. 4 is a diagram showing an example of the configuration of the projection system 2 according to the first embodiment. As shown in Fig. 4, the projection system 2 includes the projector 1 described with reference to Figs. 1-3, a first personal computer 600, and a second personal computer 700.

[0048] [3-1-1. Projector configuration] The projector 1 includes a first control unit 150, a first image communication interface 160, and a first control communication interface 170. The first image communication interface 160 is a communication interface that performs communication with the first personal computer 600 and the second personal computer 700, for example, in accordance with the HDMI (registered trademark) (High-Definition Multimedia Interface) standard. The first image communication interface 160 includes a connector that connects the first image cable CP1 and the second image cable CP2, and an interface circuit that processes signals transmitted through the connector. The connector includes a first image terminal 161 and a second image terminal 162.

[0049] Each of the first image cable CP1 and the second image cable CP2 is a so-called HDMI (registered trademark) cable. The first image cable CP1 is connected to a first image terminal 161, and the second image cable CP2 is connected to a second image terminal 162. When communication conforming to the HDMI (registered trademark) standard is established between the projector 1 and the first personal computer 600, device information is shared. The device information includes, for example, the identification information of the projector 1, the identification information of the first image terminal 161, the identification information of the first personal computer 600, and the identification information of the third image terminal 661. Furthermore, when communication conforming to the HDMI (registered trademark) standard is established between the projector 1 and the second personal computer 700, device information is shared. The device information includes, for example, the identification information of the projector 1, the identification information of the second image terminal 162, the identification information of the second personal computer 700, and the identification information of the fourth image terminal 761. Thus, the user can connect the first image cable CP1 to the first image terminal 161 and connect the second image cable CP2 to the second image terminal 162 based on the device information.

[0050] The first image communication interface 160 is an interface board having a connector and an interface circuit, and is connected to a main board on which the first processor 150A and the like of the first control unit 150 are mounted. Alternatively, the connector and interface circuit constituting the first image communication interface 160 are mounted on the main board of the first control unit 150. The first image communication interface 160 receives image data and the like from the first personal computer 600 and the second personal computer 700.

[0051] The first control communication interface 170 is a communication interface that communicates with the first personal computer 600 and the second personal computer 700 according to, for example, the Universal Serial Bus (USB) standard. The first control communication interface 170 includes a connector that connects the first control cable CC1 and the second control cable CC2, and an interface circuit that processes signals transmitted through the connector. The connector includes a first control terminal 171 and a second control terminal 172.

[0052] Each of the first control cable CC1 and the second control cable CC2 is a USB (registered trademark) cable. The first control cable CC1 is correctly connected to the first control terminal 171 as shown by a solid line in Fig. 4. Also, the first control cable CC1 may be erroneously connected to the second control terminal 172 as shown by a virtual line in Fig. 4. The second control cable CC2 is correctly connected to the second control terminal 172 as shown by a solid line in Fig. 4. Also, the second control cable CC2 may be erroneously connected to the first control terminal 171 as shown by a virtual line in Fig. 4.

[0053] The first control communication interface 170 is an interface board having a connector and an interface circuit, and is connected to a main board on which the first processor 150A and the like of the first control unit 150 are mounted. Alternatively, the connector and interface circuit constituting the first control communication interface 170 are mounted on the main board of the first control unit 150. The first control communication interface 170 transmits control signals and the like indicating the positions PS of the projection surface 10 indicated by the first indicator 50 and the second indicator 70 to the first personal computer 600 and the second personal computer 700.

[0054] [3-1-2. Configuration of the first personal computer] The first personal computer 600 includes a third control unit 650, a third image communication interface 660, a third control communication interface 670, and a first monitor 680. The first personal computer 600 is an example of a terminal. The first personal computer 600 transmits a first image signal indicating a projection image to the projector 1 via a first image cable CP1. That is, the first personal computer 600 functions as an image source. The third control unit 650 controls the operation of each unit of the first personal computer 600. The third control unit 650 is a computer device including a third memory 650B and a third processor 650A. The third memory 650B includes, for example, a volatile memory such as a RAM, and a non-volatile memory such as a ROM. The volatile memory constitutes a work area for the third processor 650A. The non-volatile memory stores a third control program PG3 executed by the third processor 650A. The third control program PG3 includes firmware and application programs.

[0055] The third image communication interface 660 is a communication interface that executes communication with the projector 1, for example, in accordance with the HDMI (registered trademark) standard. The third image communication interface 660 includes a connector for connecting the first image cable CP1, and an interface circuit for processing a signal transmitted through the connector. The connector includes a third image terminal 661. The first image cable CP1 is connected to the third image terminal 661. In other words, the image cable connected to the third image terminal 661 is described as the first image cable CP1.

[0056] The third image communication interface 660 is an interface board having a connector and an interface circuit, and is connected to a main board on which the third processor 650A and the like of the third control unit 650 are mounted. Alternatively, the connector and interface circuit constituting the third image communication interface 660 are mounted on the main board of the third control unit 650. The third image communication interface 660 transmits image data and the like to the projector 1.

[0057] The third control communication interface 670 is a communication interface that executes communication with the projector 1, for example, in accordance with the USB (registered trademark) standard. The third control communication interface 670 includes a connector for connecting the first control cable CC1, and an interface circuit for processing signals transmitted through the connector. The connector includes a third control terminal 671. The first control cable CC1 is connected to the third control terminal 671 as shown by the solid line and the virtual line in FIG. 4. In other words, the control cable connected to the third control terminal 671 is described as the first control cable CC1.

[0058] The third control communication interface 670 is an interface board having a connector and an interface circuit, and is connected to a main board on which the third processor 650A and the like of the third control unit 650 are mounted. Alternatively, the connector and interface circuit constituting the third control communication interface 670 are mounted on the main board of the third control unit 650. The third control communication interface 670 receives, from the projector 1, a control signal or the like indicating the position PS of the projection surface 10 indicated by the first indicator 50 and the second indicator 70.

[0059] The third control unit 650 includes a transfer unit 655. The third processor 650A functions as the transfer unit 655 by executing the third control program PG3. The transfer unit 655 receives the first identification information J1 via the third image terminal 661 of the third image communication interface 660. Then, the transfer unit 655 stores the first identification information J1 in the third memory 650B, and transmits the first identification information J1 to the projector 1 via the third control terminal 671.

[0060] The first monitor 680 is a display device composed of a liquid crystal display panel, an organic EL (Electro-Luminescence) panel, or the like, and displays characters and images according to the control of the third control unit 650. The first monitor 680 displays an image based on the first image signal according to the control of the third control unit 650. The content of the image displayed on the first monitor 680 is, for example, the same as the content of the projected image. When an arbitrary object is drawn in the projected image, the object is also displayed in the image displayed on the first monitor 680 based on the control signal. That is, the first personal computer 600 is controlled based on the control signal. In other words, as an "interactive function", a function in which the first personal computer 600 is controlled based on the control signal is executed. The control of the first personal computer 600 by the projector 1 based on the control signal may be called "interactive control".

[0061] [3-1-3. Configuration of the second personal computer] The second personal computer 700 includes a fourth control unit 750, a fourth image communication interface 760, a fourth control communication interface 770, and a second monitor 780. The second personal computer 700 is an example of a terminal. The second personal computer 700 transmits a second image signal indicating a projection image to the projector 1 via a second image cable CP2. That is, the second personal computer 700 functions as a source of an image. Note that the second image signal may be the same as or different from the first image signal. In other words, the content of the projection image projected from the projector 1 based on the first image signal may be the same as or different from the content of the projection image projected from the projector 1 based on the second image signal. The fourth control unit 750 controls the operation of each unit of the second personal computer 700. The fourth control unit 750 is a computer device including a fourth memory 750B and a fourth processor 750A. The fourth memory 750B includes, for example, a volatile memory such as a RAM, and a non-volatile memory such as a ROM. The volatile memory constitutes a work area for the fourth processor 750A. The non-volatile memory stores a fourth control program PG4 executed by the fourth processor 750A. The fourth control program PG4 includes firmware and application programs.

[0062] The fourth image communication interface 760 is a communication interface that executes communication with the projector 1, for example, in accordance with the HDMI (registered trademark) standard. The fourth image communication interface 760 includes a connector for connecting the second image cable CP2, and an interface circuit for processing signals transmitted through the connector. The connector includes a fourth image terminal 761. The second image cable CP2 is connected to the fourth image terminal 761. In other words, the image cable connected to the fourth image terminal 761 is described as the second image cable CP2.

[0063] The fourth image communication interface 760 is an interface board having a connector and an interface circuit, and is connected to a main board on which the fourth processor 750A and the like of the fourth control unit 750 are mounted. Alternatively, the connector and interface circuit constituting the fourth image communication interface 760 are mounted on the main board of the fourth control unit 750. The fourth image communication interface 760 transmits image data and the like to the projector 1.

[0064] The fourth control communication interface 770 is a communication interface that executes communication with the projector 1, for example, in accordance with the USB (registered trademark) standard. The fourth control communication interface 770 includes a connector for connecting the second control cable CC2, and an interface circuit for processing signals transmitted through the connector. The connector includes a fourth control terminal 771. The second control cable CC2 is connected to the fourth control terminal 771 as shown by the solid line and the virtual line in FIG. 4. In other words, the control cable connected to the fourth control terminal 771 is described as the second control cable CC2.

[0065] The fourth control communication interface 770 is an interface board having a connector and an interface circuit, and is connected to a main board on which the fourth processor 750A and the like of the fourth control unit 750 are mounted. Alternatively, the connector and interface circuit constituting the fourth control communication interface 770 are mounted on the main board of the fourth control unit 750. The fourth control communication interface 770 receives, from the projector 1, a control signal and the like indicating the position PS of the projection surface 10 indicated by the first indicator 50 and the second indicator 70.

[0066] The fourth control unit 750 includes a transfer unit 755. The fourth processor 750A functions as the transfer unit 755 by executing the fourth control program PG4. When the fourth image communication interface 760 receives the second identification information J2 via the fourth image terminal 761, the transfer unit 755 stores the second identification information J2 in the fourth memory 750B and transmits the second identification information J2 to the projector 1 via the fourth control terminal 771.

[0067] The second monitor 780 is a display device constituted by a liquid crystal display panel, an organic EL panel, or the like, and displays characters and images under the control of the fourth control unit 750. The second monitor 780 displays an image based on the second image signal in accordance with the control of the fourth control unit 750. The content of the image displayed on the second monitor 780 is, for example, the same as the content of the projected image. When an arbitrary object is drawn in the projected image, the object is also displayed in the image displayed on the second monitor 780 based on the control signal. That is, the second personal computer 700 is controlled based on the control signal. In other words, as an "interactive function", a function in which the second personal computer 700 is controlled based on the control signal is executed. The control of the second personal computer 700 by the projector 1 based on the control signal may be called "interactive control".

[0068] [3-1-4. Configuration of the first control section] The first control unit 150 includes, as functional units, a transmission unit 151, a reception unit 152, a determination unit 153, and a notification unit 154. Specifically, the first processor 150A of the first control unit 150 executes a first control program PG1 stored in the first memory 150B, thereby functioning as the transmission unit 151, the reception unit 152, the determination unit 153, and the notification unit 154.

[0069] The transmission unit 151 generates first identification information J1 and second identification information J2. The first identification information J1 is, for example, first allocation information assigned in advance to the first image terminal 161. The second identification information J2 is, for example, second allocation information assigned in advance to the second image terminal 162. The first identification information J1 is an example of device information shared by one of the projector 1 and the first personal computer 600 with the other when, for example, the first image cable CP1 is connected to the projector 1 and the first personal computer 600 and communication in accordance with the HDMI (registered trademark) standard is established. The second identification information J2 is an example of device information shared by one of the projector 1 and the second personal computer 700 with the other when, for example, the second image cable CP2 is connected to the projector 1 and the second personal computer 700 and communication in accordance with the HDMI (registered trademark) standard is established.

[0070] The transmission unit 151 stores the first identification information J1 in the first memory 150B in association with the identification information indicating the first personal computer 600. The transmission unit 151 also stores the second identification information J2 in the first memory 150B in association with the identification information indicating the second personal computer 700. The transmission unit 151 transmits the first identification information J1 from the first image terminal 161 of the first image communication interface 160 to the first personal computer 600 via the first image cable CP1. In addition, the transmission unit 151 transmits the second identification information J2 from the second image terminal 162 of the first image communication interface 160 to the second personal computer 700 via the second image cable CP2.

[0071] The receiving unit 152 receives the first identification information J1 and the second identification information J2 from the first control terminal 171 and the second control terminal 172 of the first control communication interface 170. The first identification information J1 is transmitted from the first personal computer 600 via the first control cable CC1. The second identification information J2 is transmitted from the second personal computer 700 via the second control cable CC2.

[0072] 4, when the first control cable CC1 is connected to the first control terminal 171, the receiver 152 receives the first identification information J1 from the first control terminal 171. Also, when the second control cable CC2 is connected to the second control terminal 172, the receiver 152 receives the second identification information J2 from the second control terminal 172. 4, when the second control cable CC2 is connected to the first control terminal 171, the receiver 152 receives the second identification information J2 from the first control terminal 171. Also, when the second control cable CC2 is connected to the first control terminal 171, the receiver 152 receives the first identification information J1 from the second control terminal 172, as shown by the imaginary line in FIG.

[0073] The determination unit 153 determines whether the identification information input from the first control terminal 171 is the first identification information J1 or the second identification information J2.

[0074] For example, assume that the third image terminal 661 is connected to the first image terminal 161 via the first image cable CP1. In this case, since the first personal computer 600 is the image source of the projector 1, it is preferable that the object of control based on the control signal is the first personal computer 600. This is because the user wants to perform interactive control on the terminal as the image source. In other words, when the third image terminal 661 is connected to the first image terminal 161 via the first image cable CP1, it is preferable that the terminal connected to the first control terminal 171 via the first control cable CC1 is the third control terminal 671. If the first image terminal 161 and the third image terminal 661 are connected while the first control terminal 171 and the fourth control terminal 771 are connected, the image source is the first personal computer 600 while the control object is the second personal computer 700. Therefore, the image source and the control object do not match as viewed from the projector body 100, and normal interactive control is not performed.

[0075] In contrast, in the projection system 2, the determination unit 153 determines whether the identification information input from the first control terminal 171 is the first identification information J1 or the second identification information J2, thereby making it possible to determine whether the source of the image and the control target match as viewed from the projector body 100. For example, the determination unit 153 determines whether the identification information input from the first image terminal 161 is the first identification information J1 and whether the identification information input from the first control terminal 171 is the first identification information J1. In other words, the determination unit 153 determines whether the third image terminal 661 is connected to the first image terminal 161 and the first control terminal 171 is connected to the third control terminal 671. When the identification information input from the first image terminal 161 and the identification information input from the first control terminal 171 match each other, the source of the image and the control target match as viewed from the projector body 100, and normal interactive control is performed.

[0076] When the judgment unit 153 judges that the identification information input from the first control terminal 171 is the second identification information J2, the notification unit 154 notifies a first message MG1 indicating that the control cable connected to the first control terminal 171 is invalid. The first message MG1 is, for example, text information saying "The control cable connection is incorrect." In addition, when the judgment unit 153 judges that the identification information input from the first control terminal 171 is the second identification information J2, the notification unit 154 notifies a second message MG2 encouraging the connection of the first control cable CC1 to the first control terminal 171. The second message MG2 is, for example, text information stating "Please connect the first control cable CC1 connected to the first personal computer to the first control terminal 171." The notification unit 154 displays the first message MG1 and the second message MG2 by projecting text images indicating the first message MG1 and the second message MG2 on the projection surface 10 using, for example, an OSD (On-Screen Display) function.

[0077] [3-2. Processing of the projection system] Next, processing of the projection system 2 in the first embodiment will be described with reference to Fig. 5. Fig. 5 is a flowchart showing an example of processing of the projection system 2 in the first embodiment. In other words, Fig. 5 is a flowchart showing an example of processing of the first control unit 150 of the projector 1, the third control unit 650 of the first personal computer 600, and the fourth control unit 750 of the second personal computer 700 in the first embodiment. In Fig. 5, the projector 1 is written as "PJ", the first personal computer 600 is written as "PC1", and the second personal computer 700 is written as "PC2".

[0078] A first image cable CP1 is connected between the projector 1 and the first personal computer 600. Then, communication in accordance with the HDMI (registered trademark) standard is established between the projector 1 and the first personal computer 600 via the first image cable CP1. Also, a second image cable CP2 is connected between the projector 1 and the second personal computer 700. Then, communication in accordance with the HDMI (registered trademark) standard is established between the projector 1 and the second personal computer 700 via the second image cable CP2. In addition, a first control cable CC1 is connected between the projector 1 and the first personal computer 600. In addition, a second control cable CC2 is connected between the projector 1 and the second personal computer 700. Thereafter, the process shown in the flowchart of FIG. 5 is executed.

[0079] First, in step SA101, the transmission unit 151 of the projector 1 generates first identification information J1 and second identification information J2. Then, the transmission unit 151 associates the first identification information J1 with identification information indicating the first personal computer 600 and stores it in the first memory 150B. In addition, the transmission unit 151 associates the second identification information J2 with identification information indicating the second personal computer 700 and stores it in the first memory 150B. Next, in step SA103, the transmission unit 151 transmits the first identification information J1 from the first image terminal 161 of the first image communication interface 160 to the first personal computer 600 via the first image cable CP1. Next, in step SA105, the transmission unit 151 transmits the second identification information J2 from the second image terminal 162 of the first image communication interface 160 to the second personal computer 700 via the second image cable CP2.

[0080] Next, in step SA107, the transfer unit 655 of the first personal computer 600 receives the first identification information J1. Next, in step SA109, the transfer unit 655 stores the first identification information J1 in the third memory 650B. Next, in step SA111, the transfer unit 655 transmits the first identification information J1 from the third control terminal 671 to the projector 1 via the first control cable CC1.

[0081] Next, in step SA113, the transfer unit 755 of the second personal computer 700 receives the second identification information J2. Next, in step SA115, the transfer unit 755 stores the second identification information J2 in the fourth memory 750B. Next, in step SA117, the transfer unit 755 transmits the second identification information J2 from the fourth control terminal 771 to the projector 1 via the second control cable CC2.

[0082] Next, in step SA119, the receiving unit 152 of the projector 1 receives the first identification information J1 and the second identification information J2 from the first control terminal 171 and the second control terminal 172 of the first control communication interface 170. Then, the determining unit 153 of the projector 1 determines whether or not the first identification information J1 has been received from the first control terminal 171. If the determination unit 153 determines that the first identification information J1 has been received from the first control terminal 171 (step SA119; YES), the process then ends. If the determination unit 153 determines that the first identification information J1 has not been received from the first control terminal 171 (step SA119; NO), the process proceeds to step SA121. Then, in step SA121, the determination unit 153 determines whether the second identification information J2 has been received from the first control terminal 171 or not. If the determination unit 153 determines that the second identification information J2 has not been received from the first control terminal 171 (step SA121; NO), the process returns to step SA119. If the determination unit 153 determines that the second identification information J2 has been received from the first control terminal 171 (step SA121; YES), the process proceeds to step SA123. Then, in step SA123, the notification unit 154 of the projector 1 notifies at least the first message MG1. The notification unit 154 of the projector 1 may notify the second message MG2. The first message MG1 indicates that the control cable connected to the first control terminal 171 is invalid. The second message MG2 urges the user to connect the first control cable CC1 to the first control terminal 171. After that, the process ends.

[0083] Note that, when the determination unit 153 determines that the first identification information J1 has been received from the first control terminal 171 (step SA119; YES), the process does not end, and interactive control of the first personal computer 600 by the projector 1 may be started. In this case, a control signal is selectively transmitted from the projector 1 to the first personal computer 600 corresponding to the first identification information J1, out of the first personal computer 600 and the second personal computer 700. In other words, the projector 1 has a function of selectively transmitting a control signal to the terminal corresponding to the first identification information J1, out of the first personal computer 600 and the second personal computer 700.

[0084] As described with reference to FIG. 1-FIG. 5, the transfer unit 655 of the first personal computer 600 receives the first identification information J1 from the projector 1 via the first image cable CP1, and transmits the received first identification information J1 to the projector 1. Also, the transfer unit 755 of the second personal computer 700 receives the second identification information J2 from the projector 1 via the second image cable CP2, and transmits the received second identification information J2 to the projector 1. Then, when the determination unit 153 determines that the second identification information J2 has been received from the first control terminal 171, the notification unit 154 of the projector 1 notifies at least the first message MG1. The notification unit 154 of the projector 1 may notify the second message MG2. The first message MG1 indicates that the control cable connected to the first control terminal 171 is invalid. The second message MG2 prompts the first control cable CC1 to be connected to the first control terminal 171.

[0085] Therefore, the first message MG1 allows the user to easily confirm that the control cable connected to the first control terminal 171 is incorrect. Therefore, the user can easily understand the reason why interactive control is not being performed normally. Furthermore, the second message MG2 allows the user to easily connect the first control cable CC1 to the first control terminal 171. Therefore, the user can easily resolve the reason why interactive control is not being performed normally. As a result, user convenience can be improved.

[0086] [4. Second embodiment] [4-1. Projection system configuration] Next, a projection system 2 according to a second embodiment will be described with reference to FIGS. In the following explanation, we will mainly explain the configuration of the projection system 2 according to the second embodiment that differs from the configuration of the projection system 2 according to the first embodiment, and the same configurations will be given the same reference symbols and their explanations will be omitted. FIG. 6 is a diagram showing an example of the configuration of a projection system 2 in the second embodiment. The configuration of the projector 1 shown in FIG. 6 is the same as the configuration of the projector 1 according to the first embodiment described with reference to FIG. 4, and therefore the description thereof will be omitted.

[0087] The configuration of the first personal computer 600 shown in FIG. 6 differs from the configuration of the first personal computer 600 according to the first embodiment described with reference to FIG. 4 in the following points. That is, while the third control unit 650 of the first personal computer 600 according to the first embodiment has a transfer unit 655, the third control unit 650 of the first personal computer 600 according to the second embodiment has a transmission unit 651.

[0088] The third control unit 650 includes a transmission unit 651. The third processor 650A functions as the transmission unit 651 by executing the third control program PG3. The transmission unit 651 generates the first identification information J1. The first identification information J1 is, for example, first allocation information that is allocated to the first image terminal 161 in advance. The first identification information J1 is included in the shared device information when, for example, the first image cable CP1 is connected to the projector 1 and the first personal computer 600 and communication in accordance with the HDMI (registered trademark) standard is established.

[0089] The transmission unit 651 stores the first identification information J1 in the third memory 650B. The transmission unit 651 transmits the first identification information J1 from the third image terminal 661 of the third image communication interface 660 to the projector 1 via the first image cable CP1. Furthermore, the transmission unit 651 transmits the first identification information J1 from the third control terminal 671 of the third control communication interface 670 to the projector 1 via the first control cable CC1.

[0090] The configuration of the second personal computer 700 shown in FIG. 6 differs from the configuration of the second personal computer 700 according to the first embodiment described with reference to FIG. 4 in the following points. That is, while the fourth control unit 750 of the second personal computer 700 according to the first embodiment has a transfer unit 755, the fourth control unit 750 of the second personal computer 700 according to the second embodiment has a transmission unit 751.

[0091] The fourth control unit 750 includes a transmission unit 751. The fourth processor 750A functions as the transmission unit 751 by executing the fourth control program PG4. The transmission unit 751 generates the second identification information J2. The second identification information J2 is, for example, second allocation information that is allocated to the second image terminal 162 in advance. The second identification information J2 is included in the shared device information when, for example, the second image cable CP2 is connected to the projector 1 and the second personal computer 700 and communication in accordance with the HDMI (registered trademark) standard is established.

[0092] The transmission unit 751 stores the second identification information J2 in the fourth memory 750B. The transmission unit 751 transmits the second identification information J2 from the fourth image terminal 761 of the fourth image communication interface 760 to the projector 1 via the second image cable CP2. Furthermore, the transmission unit 751 transmits the second identification information J2 from the fourth control terminal 771 of the fourth control communication interface 770 to the projector 1 via the second control cable CC2.

[0093] The configuration of the first control unit 150 shown in FIG. 6 differs from the configuration of the first control unit 150 according to the first embodiment described with reference to FIG. 4 in the following points. While the first control unit 150 according to the first embodiment includes a transmission unit 151, a reception unit 152, a determination unit 153, and a notification unit 154, the first control unit 150 according to the second embodiment includes a reception unit 152, a determination unit 153, and a notification unit 154. In other words, the first control unit 150 according to the second embodiment does not include the transmission unit 151. Specifically, the first processor 150A of the first control unit 150 executes the first control program PG1 stored in the first memory 150B, thereby functioning as a receiving unit 152, a determining unit 153, and an informing unit 154.

[0094] The receiving unit 152 in the second embodiment has the same functions as the receiving unit 152 in the first embodiment, but differs from it in that it has the following functions. The receiving unit 152 receives the first identification information J1 from the first image terminal 161 of the first image communication interface 160. The receiving unit 152 also receives the second identification information J2 from the second image terminal 162 of the first image communication interface 160. Furthermore, the receiving unit 152 stores the first identification information J1 in the first memory 150B in association with the identification information indicating the first personal computer 600. The receiving unit 152 also stores the second identification information J2 in the first memory 150B in association with the identification information indicating the second personal computer 700.

[0095] The determination unit 153 in the second embodiment executes the same process as the determination unit 153 in the first embodiment. Moreover, the notification unit 154 in the second embodiment executes the same process as the notification unit 154 in the first embodiment.

[0096] [4-2. Processing of the projection system] Next, processing of the projection system 2 in the second embodiment will be described with reference to FIG. 7. FIG. 7 is a flowchart showing an example of processing of the projection system 2 in the second embodiment. In other words, FIG. 7 is a flowchart showing an example of processing of the first control unit 150 of the projector 1, the third control unit 650 of the first personal computer 600, and the fourth control unit 750 of the second personal computer 700 in the second embodiment. In FIG. 7, the projector 1 is written as "PJ", the first personal computer 600 is written as "PC1", and the second personal computer 700 is written as "PC2".

[0097] A first image cable CP1 is connected between the projector 1 and the first personal computer 600. Then, communication in accordance with the HDMI (registered trademark) standard is established between the projector 1 and the first personal computer 600 via the first image cable CP1. Also, a second image cable CP2 is connected between the projector 1 and the second personal computer 700. Then, communication in accordance with the HDMI (registered trademark) standard is established between the projector 1 and the second personal computer 700 via the second image cable CP2. In addition, a first control cable CC1 is connected between the projector 1 and the first personal computer 600. In addition, a second control cable CC2 is connected between the projector 1 and the second personal computer 700. Thereafter, the process shown in the flowchart of FIG. 7 is executed.

[0098] First, in step SB101, the transmission unit 651 of the first personal computer 600 generates the first identification information J1. Next, in step SB103, the transmission unit 651 stores the first identification information J1 in the third memory 650B. Next, in step SB105, the transmission unit 651 transmits the first identification information J1 from the third image terminal 661 of the third image communication interface 660 to the projector 1 via the first image cable CP1. The transmission unit 651 also transmits the first identification information J1 from the third control terminal 671 of the third control communication interface 670 to the projector 1 via the first control cable CC1.

[0099] Next, in step SB107, the transmission unit 751 of the second personal computer 700 generates second identification information J2. Next, in step SB109, the transmission unit 751 stores the second identification information J2 in the fourth memory 750B. Next, in step SB111, the transmission unit 751 transmits the second identification information J2 from the fourth image terminal 761 of the fourth image communication interface 760 via the second image cable CP2 to the projector 1. In addition, the transmission unit 751 transmits the second identification information J2 from the fourth control terminal 771 of the fourth control communication interface 770 to the projector 1 via the second control cable CC2.

[0100] Next, in step SB113, the receiving unit 152 of the projector 1 receives the first identification information J1 from the first image terminal 161 of the first image communication interface 160. Furthermore, the receiving unit 152 stores the first identification information J1 in the first memory 150B in association with the identification information indicating the first personal computer 600. Next, in step SB115, the receiving unit 152 receives the second identification information J2 from the second image terminal 162 of the first image communication interface 160. The receiving unit 152 also stores the second identification information J2 in the first memory 150B in association with the identification information indicating the second personal computer 700.

[0101] Next, in step SB117, the receiving unit 152 of the projector 1 receives the first identification information J1 and the second identification information J2 from the first control terminal 171 and the second control terminal 172 of the first control communication interface 170. Then, the determining unit 153 of the projector 1 determines whether or not the first identification information J1 has been received from the first control terminal 171. If the determination unit 153 determines that the first identification information J1 has been received from the first control terminal 171 (step SB117; YES), the process then ends. If the determination unit 153 determines that the first identification information J1 has not been received from the first control terminal 171 (step SB117; NO), the process proceeds to step SB119. Then, in step SB119, the decision unit 153 decides whether or not the second identification information J2 has been received from the first control terminal 171. If the determination unit 153 determines that the second identification information J2 has not been received from the first control terminal 171 (step SB119; NO), the process returns to step SB117. If the determination unit 153 determines that the second identification information J2 has been received from the first control terminal 171 (step SB119; YES), the process proceeds to step SB121. Then, in step SB121, the notification unit 154 notifies at least the first message MG1. The notification unit 154 of the projector 1 may notify the second message MG2. The first message MG1 indicates that the control cable connected to the first control terminal 171 is invalid. The second message MG2 urges the user to connect the first control cable CC1 to the first control terminal 171. After that, the process ends.

[0102] As described with reference to FIGS. 1-3 and 6-7, the transmission unit 651 of the first personal computer 600 transmits the first identification information J1 to the projector 1 via the first control cable CC1. Moreover, the transmission unit 751 of the second personal computer 700 transmits the second identification information J2 to the projector 1 via the second control cable CC2. Then, when the determination unit 153 determines that the second identification information J2 has been received from the first control terminal 171, the notification unit 154 of the projector 1 notifies at least the first message MG1. The notification unit 154 of the projector 1 may notify the second message MG2. The first message MG1 indicates that the control cable connected to the first control terminal 171 is invalid. The second message MG2 urges the connection of the first control cable CC1 to the first control terminal 171.

[0103] Therefore, the first message MG1 allows the user to easily confirm that the control cable connected to the first control terminal 171 is incorrect. Therefore, the user can easily understand the reason why interactive control is not being performed normally. Furthermore, the second message MG2 allows the user to easily connect the first control cable CC1 to the first control terminal 171. Therefore, the user can easily resolve the reason why interactive control is not being performed normally. As a result, user convenience can be improved.

[0104] [5. Third embodiment] [5-1. Projection system configuration] Next, a projection system 2 according to a third embodiment will be described with reference to FIGS. In the following explanation, we will mainly explain the configuration of the projection system 2 according to the third embodiment that differs from the configuration of the projection system 2 according to the first embodiment, and the same configurations will be given the same reference symbols and their explanations will be omitted. FIG. 8 is a diagram showing an example of the configuration of a projection system 2 in the third embodiment. The configuration of the projector 1 shown in FIG. 8 is the same as the configuration of the projector 1 according to the first embodiment described with reference to FIG. 4, and therefore the description thereof will be omitted.

[0105] The configuration of the first control unit 150 shown in FIG. 8 differs from the configuration of the first control unit 150 according to the first embodiment described with reference to FIG. 4 in the following points. While the first control unit 150 of the first embodiment has a transmitting unit 151, a receiving unit 152, a judgment unit 153, and an alarm unit 154, the first control unit 150 of the third embodiment has a transmitting unit 151 but does not have the receiving unit 152, the judgment unit 153, or the alarm unit 154. Specifically, the first processor 150A of the first control unit 150 functions as a transmission unit 151 by executing a first control program PG1 stored in the first memory 150B.

[0106] The transmitting unit 151 in the third embodiment has the same functions as the transmitting unit 151 in the first embodiment, but differs from it in that it has the following functions. The transmitter 151 transmits the first identification information J1 from the first control terminal 171 of the first control communication interface 170 to the first personal computer 600 or the second personal computer 700 via the first control cable CC1 or the second control cable CC2. In addition, the transmitter 151 transmits the second identification information J2 from the second control terminal 172 of the first control communication interface 170 to the first personal computer 600 or the second personal computer 700 via the first control cable CC1 or the second control cable CC2.

[0107] The configuration of the first personal computer 600 shown in FIG. 8 differs from the configuration of the first personal computer 600 according to the first embodiment described with reference to FIG. 4 in the following points. That is, while the third control unit 650 of the first personal computer 600 in the first embodiment has a transfer unit 655, the third control unit 650 of the first personal computer 600 in the third embodiment has a receiving unit 652, a determination unit 653, and an alarm unit 654.

[0108] The third control unit 650 includes a receiving unit 652, a determination unit 653, and a notification unit 654. Specifically, the third processor 650A functions as the receiving unit 652, the determination unit 653, and the notification unit 654 by executing the third control program PG3.

[0109] The receiving unit 652 receives the first identification information J1 from the third image terminal 661 of the third image communication interface 660. The first identification information J1 is transmitted from the projector 1 via the first image cable CP1. Moreover, the receiving unit 652 stores the first identification information J1 in the third memory 650B.

[0110] 8, when the first control cable CC1 is connected to the first control terminal 171, the receiver 652 receives the first identification information J1 from the first control cable CC1. Also, as shown by the phantom line in FIG 8, when the first control cable CC1 is connected to the second control terminal 172, the receiver 652 receives the second identification information J2 from the first control cable CC1.

[0111] The determination unit 653 determines whether the identification information input from the third control terminal 671 is the first identification information J1 or the second identification information J2.

[0112] When the judgment unit 653 judges that the identification information input from the third control terminal 671 is the second identification information J2, the notification unit 654 notifies a first message MG1 indicating that the control cable connected to the first control terminal 171 is invalid. The first message MG1 is, for example, text information saying "The control cable connection is incorrect." In addition, when the judgment unit 653 judges that the identification information input from the third control terminal 671 is the second identification information J2, the notification unit 654 notifies a second message MG2 prompting the user to connect the first control cable CC1 to the first control terminal 171. The second message MG2 is, for example, text information stating "Please connect the first control cable CC1 connected to the first personal computer to the first control terminal 171." The notification unit 654 displays, for example, on the display of the first personal computer 600, text images indicating the first message MG1 and the second message MG2.

[0113] The configuration of the second personal computer 700 shown in FIG. 8 differs from the configuration of the second personal computer 700 according to the first embodiment described with reference to FIG. 4 in the following points. That is, while the fourth control unit 750 of the second personal computer 700 in the first embodiment has a transfer unit 755, the fourth control unit 750 of the second personal computer 700 in the second embodiment has a receiving unit 752, a determination unit 753, and an alarm unit 754.

[0114] The fourth control unit 750 includes a receiving unit 752, a determination unit 753, and a notification unit 754. Specifically, the fourth processor 750A functions as the receiving unit 752, the determination unit 753, and the notification unit 754 by executing the fourth control program PG4.

[0115] The receiving unit 752 receives the second identification information J2 from the fourth image terminal 761 of the fourth image communication interface 760. The second identification information J2 is transmitted from the projector 1 via the second image cable CP2. Moreover, the receiving unit 752 stores the second identification information J2 in the fourth memory 750B.

[0116] 8, when the second control cable CC2 is connected to the second control terminal 172, the receiver 752 receives the second identification information J2 from the second control cable CC2. Also, as shown by the phantom line in Fig. 8, when the second control cable CC2 is connected to the first control terminal 171, the receiver 752 receives the first identification information J1 from the second control cable CC2.

[0117] The determination unit 753 determines whether the identification information input from the fourth control terminal 771 is the first identification information J1 or the second identification information J2.

[0118] When the judgment unit 753 judges that the identification information input from the fourth control terminal 771 is the first identification information J1, the notification unit 754 notifies a third message MG3 indicating that the control cable connected to the second control terminal 172 is invalid. The first message MG3 is, for example, text information saying "The control cable connection is incorrect." In addition, when the judgment unit 753 judges that the identification information input from the fourth control terminal 771 is the first identification information J1, the notification unit 754 notifies a fourth message MG4 prompting the user to connect the second control cable CC2 to the second control terminal 172. The fourth message MG4 is, for example, text information stating "Please connect the second control cable CC2, which is connected to the second personal computer, to the second control terminal 172." The notification unit 654 displays, for example, text images indicating the third message MG3 and the fourth message MG4 on the display of the second personal computer 700.

[0119] [5-2. Processing of the projection system] Next, processing of the projection system 2 in the third embodiment will be described with reference to Fig. 9. Fig. 9 is a flowchart showing an example of processing of the projection system 2 in the third embodiment. In other words, Fig. 9 is a flowchart showing an example of processing of the first control unit 150 of the projector 1, the third control unit 650 of the first personal computer 600, and the fourth control unit 750 of the second personal computer 700 in the third embodiment. In Fig. 9, the projector 1 is written as "PJ", the first personal computer 600 is written as "PC1", and the second personal computer 700 is written as "PC2".

[0120] A first image cable CP1 is connected between the projector 1 and the first personal computer 600. Then, communication in accordance with the HDMI (registered trademark) standard is established between the projector 1 and the first personal computer 600 via the first image cable CP1. Also, a second image cable CP2 is connected between the projector 1 and the second personal computer 700. Then, communication in accordance with the HDMI (registered trademark) standard is established between the projector 1 and the second personal computer 700 via the second image cable CP2. In addition, a first control cable CC1 is connected between the projector 1 and the first personal computer 600. In addition, a second control cable CC2 is connected between the projector 1 and the second personal computer 700. Thereafter, the process shown in the flowchart of FIG. 9 is executed.

[0121] First, in step SC101, the transmission unit 151 of the projector 1 generates the first identification information J1 and the second identification information J2. Next, in step SC103, the transmission unit 151 transmits the first identification information J1 from the first image terminal 161 of the first image communication interface 160 to the first personal computer 600 via the first image cable CP1. In addition, the transmission unit 651 transmits the first identification information J1 from the first control terminal 171 of the first control communication interface 170 to the first personal computer 600 or the second personal computer 700 via the first control cable CC1 or the second control cable CC2. Next, in step SC105, the transmission unit 151 transmits the second identification information J2 from the second image terminal 162 of the first image communication interface 160 to the second personal computer 700 via the second image cable CP2. In addition, the transmission unit 651 transmits the second identification information J2 from the second control terminal 172 of the first control communication interface 170 to the first personal computer 600 or the second personal computer 700 via the first control cable CC1 or the second control cable CC2.

[0122] Next, in step SC107, the receiving section 652 of the first personal computer 600 receives the first identification information J1 from the third image terminal 661 of the third image communication interface 660. Next, in step SC109, the receiving section 652 stores the first identification information J1 in the third memory 650B. Next, in step SC111, the determination unit 653 determines whether or not the first identification information J1 has been received from the first control cable CC1.

[0123] If the determination unit 653 determines that the first identification information J1 has been received from the first control cable CC1 (step SC111; YES), the process ends. If the determination unit 653 determines that the first identification information J1 has not been received from the first control cable CC1 (step SC111; NO), the process proceeds to step SC113. Then, in step SC113, the determination unit 653 determines whether or not the second identification information J2 has been received from the first control cable CC1. If the determination unit 653 determines that the second identification information J2 has not been received from the first control cable CC1 (step SC113; NO), the process returns to step SC111. If the determination unit 653 determines that the second identification information J2 has been received from the first control cable CC1 (step SC113; YES), the process proceeds to step SC115. Then, in step SC115, the notification unit 654 notifies at least the first message MG1. The notification unit 154 of the projector 1 may notify the second message MG2. The first message MG1 indicates that the control cable connected to the first control terminal 171 is invalid. The second message MG2 urges the user to connect the first control cable CC1 to the first control terminal 171. After that, the process ends.

[0124] Next, in step SC117, the receiving section 752 of the second personal computer 700 receives the second identification information J2 from the fourth image terminal 761 of the fourth image communication interface 760. Next, in step SC119, the receiving section 752 stores the second identification information J2 in the fourth memory 750B. Next, in step SC121, the determination unit 753 determines whether or not the second identification information J2 has been received from the second control cable CC2.

[0125] If the determination unit 753 determines that the second identification information J2 has been received from the second control cable CC2 (step SC121; YES), the process ends. If the determination unit 753 determines that the second identification information J2 has not been received from the second control cable CC2 (step SC121; NO), the process proceeds to step SC123. Then, in step SC123, the decision unit 753 decides whether or not the first identification information J1 has been received from the second control cable CC2. If the determination unit 753 determines that the first identification information J1 has not been received from the second control cable CC2 (step SC123; NO), the process returns to step SC121. If the determination unit 753 determines that the first identification information J1 has been received from the second control cable CC2 (step SC123; YES), the process proceeds to step SC125. Then, in step SC125, the notification unit 754 notifies a third message MG3 and a fourth message MG4. The third message MG3 indicates that the control cable connected to the second control terminal 172 is invalid. The fourth message MG4 prompts the user to connect the second control cable CC2 to the second control terminal 172. Then, the process ends.

[0126] As described with reference to FIGS. 1-3 and 8-9, the transmission unit 151 of the projector 1 transmits the first identification information J1 from the first control terminal 171 of the first control communication interface 170 to the first personal computer 600 or the second personal computer 700 via the first control cable CC1 or the second control cable CC2. In addition, the transmission unit 151 transmits the second identification information J2 from the second control terminal 172 of the first control communication interface 170 to the first personal computer 600 or the second personal computer 700 via the first control cable CC1 or the second control cable CC2. Then, when the determination unit 653 of the first personal computer 600 determines that the second identification information J2 has been received from the first control cable CC1, the notification unit 654 notifies at least the first message MG1. The notification unit 154 of the projector 1 may notify the second message MG2. The first message MG1 indicates that the control cable connected to the first control terminal 171 is invalid. The second message MG2 urges the user to connect the first control cable CC1 to the first control terminal 171. Furthermore, when the determination unit 753 of the second personal computer 700 determines that the first identification information J1 has been received from the second control cable CC2, the notification unit 754 notifies a third message MG3 and a fourth message MG4. The third message MG3 indicates that the control cable connected to the second control terminal 172 is invalid. The fourth message MG4 urges the user to connect the second control cable CC2 to the second control terminal 172.

[0127] Therefore, the user can easily confirm from the first message MG1 that the control cable connected to the first control terminal 171 is incorrect. Therefore, the user can easily understand the reason why interactive control is not being performed normally. Furthermore, the user can easily connect the first control cable CC1 to the first control terminal 171 in accordance with the second message MG2. Therefore, the user can easily resolve the reason why interactive control is not being performed normally. As a result, user convenience can be improved. Furthermore, the third message MG3 allows the user to easily confirm that the control cable connected to the second control terminal 172 is incorrect. Therefore, the user can easily understand the reason why interactive control is not being performed properly. Furthermore, the fourth message MG4 allows the user to easily connect the second control cable CC2 to the second control terminal 172. Therefore, the user can easily resolve the reason why interactive control is not being performed properly. As a result, user convenience can be improved.

[0128] [6. Fourth embodiment] [6-1. Projection system configuration] Next, a projection system 2 according to a fourth embodiment will be described with reference to FIGS. In the following explanation, we will mainly explain the configuration of the projection system 2 according to the fourth embodiment that differs from the configuration of the projection system 2 according to the first embodiment, and the same configurations will be given the same reference symbols and their explanations will be omitted. FIG. 10 is a diagram showing an example of the configuration of a projection system 2 in the fourth embodiment. The configuration of the projector 1 shown in FIG. 10 is the same as the configuration of the projector 1 according to the first embodiment described with reference to FIG. 4, and therefore the description thereof will be omitted.

[0129] The configuration of the first personal computer 600 shown in FIG. 10 is the same as the configuration of the first personal computer 600 according to the first embodiment described with reference to FIG. 4, and therefore a description thereof will be omitted. However, the function of the transfer unit 655 shown in Fig. 10 differs from the function of the transfer unit 655 shown in Fig. 4. The transfer unit 655 shown in Fig. 10 receives the first identification information J1 or the second identification information J2 via a third control terminal 671 of a third control communication interface 670. In addition, the transfer unit 655 stores the received identification information in a third memory 650B, and transmits the received identification information to the projector 1 via a third image terminal 661 of a third image communication interface 660 and a first image cable CP1.

[0130] The configuration of the second personal computer 700 shown in FIG. 10 is the same as the configuration of the second personal computer 700 according to the first embodiment described with reference to FIG. 4, and therefore a description thereof will be omitted. However, the function of the transfer unit 755 shown in Fig. 10 differs from the function of the transfer unit 755 shown in Fig. 4. The transfer unit 755 shown in Fig. 10 receives the first identification information J1 or the second identification information J2 via a fourth control terminal 771 of a fourth control communication interface 770. In addition, the transfer unit 655 stores the received identification information in a fourth memory 750B, and transmits the received identification information to the projector 1 via a fourth image terminal 761 of a fourth image communication interface 760 and the second image cable CP2.

[0131] The configuration of the first control unit 150 shown in Fig. 10 is the same as the configuration of the first control unit 150 according to the first embodiment described with reference to Fig. 4. However, since the configurations of the transmitting unit 151, the receiving unit 152, the determining unit 153, and the notifying unit 154 constituting the first control unit 150 are different, the differences will be described below.

[0132] The transmitting unit 151 shown in Fig. 4 transmits the first identification information J1 via the first image cable CP1 and transmits the second identification information J2 via the second image cable CP2. In contrast, the transmitting unit 151 shown in Fig. 10 transmits the first identification information J1 and the second identification information J2 via the first control cable CC1 and the second control cable CC2. The transmission unit 151 transmits the first identification information J1 and the second identification information J2 from the first control terminal 171 and the second control terminal 172 of the first control communication interface 170 to the first personal computer 600 and the second personal computer 700.

[0133] The receiving unit 152 shown in Fig. 4 receives the first identification information J1 and the second identification information J2 via the first control cable CC1 and the second control cable CC2. In contrast, the receiving unit 152 shown in Fig. 10 receives the first identification information J1 and the second identification information J2 via the first image cable CP1 and the second image cable CP2.

[0134] 10, when the first control cable CC1 is connected to the first control terminal 171, the transmitter 151 transmits the first identification information J1 to the first personal computer 600 via the first control cable CC1. Also, when the second control cable CC2 is connected to the second control terminal 172, the transmitter 151 transmits the second identification information J2 to the second personal computer 700 via the second control cable CC2. In this case, the receiving unit 152 receives the first identification information J1 from the first personal computer 600 via the first image cable CP1, and receives the second identification information J2 from the second personal computer 700 via the second image cable CP2.

[0135] 10, when the first control cable CC1 is connected to the second control terminal 172, the transmitter 151 transmits the second identification information J2 to the first personal computer 600 via the first control cable CC1. Also, when the second control cable CC2 is connected to the first control terminal 171, the transmitter 151 transmits the first identification information J1 to the second personal computer 700 via the second control cable CC2. In this case, the receiving unit 152 receives the second identification information J2 from the first personal computer 600 via the first image cable CP1, and receives the first identification information J1 from the second personal computer 700 via the second image cable CP2.

[0136] The determination unit 153 shown in Fig. 4 determines whether the identification information input from the first control terminal 171 is the first identification information J1 or the second identification information J2. In contrast, the determination unit 153 shown in Fig. 10 determines whether the identification information input from the first image cable CP1 to the first image terminal 161 is the first identification information J1 or the second identification information J2.

[0137] The notification unit 154 shown in Fig. 4 notifies the first message MG1 and the second message MG2 when the determination unit 153 determines that the identification information input from the first control terminal 171 is the second identification information J2. In contrast, the notification unit 154 shown in Fig. 10 notifies the first message MG1 and the second message MG2 when the determination unit 153 determines that the identification information input from the first image cable CP1 to the first image terminal 161 is the second identification information J2.

[0138] [6-2. Processing of projection system] The processing of the projection system 2 in the fourth embodiment will be described with reference to Fig. 11. Fig. 11 is a flowchart showing an example of the processing of the projection system 2 in the fourth embodiment. In other words, Fig. 11 is a flowchart showing an example of the processing of the first control unit 150 of the projector 1, the third control unit 650 of the first personal computer 600, and the fourth control unit 750 of the second personal computer 700 in the fourth embodiment. In Fig. 11, the projector 1 is written as "PJ", the first personal computer 600 is written as "PC1", and the second personal computer 700 is written as "PC2".

[0139] A first image cable CP1 is connected between the projector 1 and the first personal computer 600. Then, communication in accordance with the HDMI (registered trademark) standard is established between the projector 1 and the first personal computer 600 via the first image cable CP1. Also, a second image cable CP2 is connected between the projector 1 and the second personal computer 700. Then, communication in accordance with the HDMI (registered trademark) standard is established between the projector 1 and the second personal computer 700 via the second image cable CP2. In addition, a first control cable CC1 is connected between the projector 1 and the first personal computer 600. In addition, a second control cable CC2 is connected between the projector 1 and the second personal computer 700. Thereafter, the process shown in the flowchart of FIG. 11 is executed.

[0140] First, in step SD101, the transmission unit 151 of the projector 1 generates first identification information J1 and second identification information J2. Then, the transmission unit 151 associates the first identification information J1 with identification information indicating the first personal computer 600 and stores them in the first memory 150B. The transmission unit 151 also associates the second identification information J2 with identification information indicating the second personal computer 700 and stores them in the first memory 150B. Next, in step SD103, the transmitter 151 transmits the first identification information J1 from the first control terminal 171 to the first personal computer 600 or the second personal computer 700 via the first control cable CC1 or the second control cable CC2. Next, in step SD105, the transmitter 151 transmits the second identification information J2 from the second control terminal 172 to the first personal computer 600 or the second personal computer 700 via the first control cable CC1 or the second control cable CC2.

[0141] Next, in step SD107, the transfer unit 655 of the first personal computer 600 receives the first identification information J1 or the second identification information J2. Next, in step SD109, the transfer section 655 stores the identification information received in step SD107 in the third memory 650B. Next, in step SD111, the transfer section 655 transmits the identification information received in step SD107 from the third image terminal 661 to the projector 1 via the first image cable CP1.

[0142] Next, in step SD113, the transfer section 755 of the second personal computer 700 receives the first identification information J1 or the second identification information J2. Next, in step SD115, the transfer section 755 stores the identification information received in step SD113 in the fourth memory 750B. Next, in step SD117, the transfer unit 755 transmits the identification information received in step SD113 from the fourth image terminal 761 to the projector 1 via the second image cable CP2.

[0143] Next, in step SD119, the receiving unit 152 of the projector 1 receives the first identification information J1 and the second identification information J2 from the first image terminal 161 and the second image terminal 162 of the first image communication interface 160. Then, the determining unit 153 of the projector 1 determines whether or not the first identification information J1 has been received from the first image terminal 161. If the determination unit 153 determines that the first identification information J1 has been received from the first image terminal 161 (step SD119; YES), the process ends. If the determination unit 153 determines that the first identification information J1 has not been received from the first image terminal 161 (step SD119; NO), the process proceeds to step SD121. Then, in step SD121, the determination unit 153 determines whether the second identification information J2 has been received from the first image terminal 161 or not. If the determination unit 153 determines that the second identification information J2 has not been received from the first image terminal 161 (step SD121; NO), the process returns to step SD119. If the determination unit 153 determines that the second identification information J2 has been received from the first image terminal 161 (step SD121; YES), the process proceeds to step SD123. Then, in step SD123, the notification unit 154 of the projector 1 notifies at least the first message MG1. The notification unit 154 of the projector 1 may notify the second message MG2. The first message MG1 indicates that the control cable connected to the first control terminal 171 is invalid. The second message MG2 urges the user to connect the first control cable CC1 to the first control terminal 171. After that, the process ends.

[0144] As described with reference to FIG. 10-FIG. 11, the transfer unit 655 of the first personal computer 600 receives the first identification information J1 or the second identification information J2 from the projector 1 via the first control cable CC1, and transmits the received identification information to the projector 1. Also, the transfer unit 755 of the second personal computer 700 receives the first identification information J1 or the second identification information J2 from the projector 1 via the second control cable CC2, and transmits the received identification information to the projector 1. Then, when the determination unit 153 determines that the second identification information J2 has been received from the first image terminal 161, the notification unit 154 of the projector 1 notifies the first message MG1 and the second message MG2. The first message MG1 indicates at least one of that the control cable connected to the first control terminal 171 is unauthorized or that the image cable connected to the first image terminal 161 is unauthorized. The second message MG2 prompts at least one of connecting the first control cable CC1 to the first control terminal 171 and connecting the first image cable CP1 to the first image terminal 161.

[0145] Therefore, the first message MG1 allows the user to easily confirm that the control cable connected to the first control terminal 171 is incorrect. Therefore, the user can easily understand the reason why interactive control is not being performed normally. Furthermore, the second message MG2 allows the user to easily connect the first control cable CC1 to the first control terminal 171. Therefore, the user can easily resolve the reason why interactive control is not being performed normally. As a result, user convenience can be improved.

[0146] [7. Effects] As described above, the control method of the projection system 2 according to the first embodiment includes a projector 1 that projects a projection image onto a projection surface 10, receives a user's operation on the projection surface 10, and generates a control signal indicating a position PS of the operation on the projection surface 10, a first personal computer 600 that is communicatively connected to the projector 1 and controlled based on the control signal, and a second personal computer 700 that is communicatively connected to the projector 1 and controlled based on the control signal, the first personal computer 600 is configured to transmit a first image signal indicating the projection image to the projector 1 via a first image cable CP1 and receive the control signal from the projector 1 via a first control cable CC1, the second personal computer 700 is configured to transmit a second image signal indicating the projection image to the projector 1 via a second image cable CP2 and receive the control signal from the projector 1 via a second control cable CC2, and the projector 1 includes a first control terminal 171 to which the first control cable CC1 is connected, and a second control cable CP3 to which the second control cable CC4 is connected. and a second control terminal 172 to which CC2 is connected, the projector 1 is capable of transmitting first identification information J1 to a first personal computer 600 via a first image cable CP1, and is capable of transmitting second identification information J2 to a second personal computer 700 via a second image cable CP2, and the first personal computer 600 is capable of transmitting the first identification information J1 to the projector 1 via the first control cable CC1 when receiving the first identification information J1, When the personal computer 700 receives the second identification information J2, it can transmit the second identification information J2 to the projector 1 via the second control cable CC2. When the first personal computer 600 is connected to the projector 1 via the first image cable CP1 and a control cable is connected to the first control terminal 171, the projector 1 determines whether the identification information input from the first control terminal 171 is the first identification information J1 or the second identification information J2, and when it is determined that the identification information is the second identification information J2,and notifying a first message MG1 indicating that the control cable connected to the first control terminal 171 is invalid.

[0147] In the above configuration, the control cable connected to the first control terminal 171 is, for example, any one of the first control cable CC1, the second control cable CC2, and other control cables. When the projector 1 detects that any one of the first control cable CC1, the second control cable CC2, and other control cables is connected to the first control terminal 171, it determines that the control cable is connected.

[0148] In this way, the projector 1 can transmit the first identification information J1 to the first personal computer 600 via the first image cable CP1, and can transmit the second identification information J2 to the second personal computer 700 via the second image cable CP2. Furthermore, when the first personal computer 600 receives the first identification information J1, it can transmit the first identification information J1 to the projector 1 via the first control cable CC1. When the second personal computer 700 receives the second identification information J2, it can transmit the second identification information J2 to the projector 1 via the second control cable CC2. When a first personal computer 600 is connected to the projector 1 via a first image cable CP1 and a control cable is connected to the first control terminal 171, the projector 1 determines whether the identification information input from the first control terminal 171 is the first identification information J1 or the second identification information J2, and if it is determined that the identification information is the second identification information J2, it issues a first message MG1 indicating that the control cable connected to the first control terminal 171 is invalid. Therefore, the user can easily confirm from the first message MG1 that the control cable connected to the first control terminal 171 is unauthorized. Therefore, the user can easily understand the cause of the interactive control not being executed normally. As a result, the user's convenience can be improved.

[0149] In addition, in the control method for the projection system 2 according to the first embodiment, the projector 1 issues a notification by projecting a first message MG1 onto the projection surface . In this way, the projector 1 notifies the user by projecting the first message MG1 onto the projection surface 10, so the user can easily visually recognize the first message MG1. Therefore, by visually recognizing the first message MG1, the user can easily confirm that the control cable connected to the first control terminal 171 is unauthorized. Therefore, the user can easily grasp the cause of the interactive control not being executed normally. As a result, user convenience can be improved.

[0150] In addition, in the control method of the projection system 2 according to the first embodiment, the projector 1 includes notifying a second message MG2 encouraging connection of the first control cable CC1 to the first control terminal 171 when the identification information is determined to be the second identification information J2. In this way, when it is determined that the identification information is the second identification information J2, a second message MG2 is displayed to prompt the user to connect the first control cable CC1 to the first control terminal 171. The second message MG2 then enables the user to easily connect the first control cable CC1 to the first control terminal 171. This allows the user to easily resolve the cause of the interactive control not being performed normally. This improves user convenience.

[0151] Furthermore, in the control method for the projection system 2 according to the first embodiment, the projector 1 includes a first image terminal 161 to which a first image cable CP1 can be connected and a second image terminal 162 to which a second image cable CP2 can be connected, and the first identification information J1 is first allocation information pre-assigned to the first image terminal 161, and the second identification information J2 is second allocation information pre-assigned to the second image terminal 162. In this way, the first identification information J1 is first allocation information assigned in advance to the first image terminal 161, and the second identification information J2 is second allocation information assigned in advance to the second image terminal 162. Therefore, the projector 1 can easily generate the first identification information J1 and the second identification information J2. Therefore, the configuration of the projector 1 can be simplified.

[0152] The projector 1 according to the first embodiment projects a projection image onto a projection surface 10, accepts a user's operation on the projection surface 10, and generates a control signal indicating a position PS of the operation on the projection surface 10. The projector 1 is communicably connected to a first personal computer 600 and a second personal computer 700. The first personal computer 600 is configured to transmit a first image signal indicating the projection image to the projector 1 via a first image cable CP1, receive the control signal from the projector 1 via a first control cable CC1, and be controlled based on the control signal. When the first identification information J1 is received from the projector 1, the second personal computer 700 is configured to transmit the first identification information J1 to the projector 1 via the first control cable CC1. The second personal computer 700 is configured to transmit a second image signal indicating the projection image to the projector 1 via a second image cable CP2, receive the control signal from the projector 1 via a second control cable CC2, and be controlled based on the control signal. When the identification information J2 is received, the projector 1 is configured to transmit the second identification information J2 to the projector 1 via the second control cable CC2. The projector 1 includes a first control terminal 171 to which the first control cable CC1 is connected, a second control terminal 172 to which the second control cable CC2 is connected, and a first processor 150A. The first processor 150A transmits the first identification information J1 to the first personal computer 600 via the first image cable CP1, and transmits the second identification information J2 to the second personal computer 600 via the second image cable CP2. 700, and when the first personal computer 600 is connected to the projector 1 via the first image cable CP1 and a control cable is connected to the first control terminal 171, determines whether the identification information input from the first control terminal 171 is the first identification information J1 or the second identification information J2, and when it is determined that the identification information is the second identification information J2, notifies a first message MG1 indicating that the control cable connected to the first control terminal 171 is invalid.

[0153] In this configuration, the control cable connected to the first control terminal 171 is, for example, any one of the first control cable CC1, the second control cable CC2, and other control cables. When the projector 1 detects that any one of the first control cable CC1, the second control cable CC2, and other control cables is connected to the first control terminal 171, it determines that the control cable is connected. According to the projector 1 of the first embodiment, the same effects as those of the control method for the projection system 2 of the first embodiment are achieved.

[0154] A control method for a projection system 2 according to a second embodiment includes a projector 1 that projects a projection image onto a projection surface 10, receives a user's operation on the projection surface 10, and generates a control signal indicating a position PS of the operation on the projection surface 10, a first personal computer 600 that is communicatively connected to the projector 1, and a second personal computer 700 that is communicatively connected to the projector 1, the first personal computer 600 being configured to transmit a first image signal indicating the projection image to the projector 1 via a first image cable CP1, receive the control signal from the projector 1 via a first control cable CC1, and be controlled based on the control signal, the second personal computer 700 being configured to transmit a second image signal indicating the projection image to the projector 1 via a second image cable CP2, receive the control signal from the projector 1 via a second control cable CC2, and be controlled based on the control signal, the projector 1 being configured to transmit a second image signal indicating the projection image to the projector 1 via a second image cable CP2, receive the control signal from the projector 1 via a second control cable CC2, and be controlled based on the control signal, a first control terminal 171 and a second control terminal 172 to which a first personal computer 600 and a second control cable CC2 are connected, the first personal computer 600 being capable of transmitting first identification information J1 to the projector 1 via the first image cable CP1 and the first control cable CC1, respectively, and the second personal computer 700 being capable of transmitting second identification information J2 to the projector 1 via the second image cable CP2 and the second control cable CC2, the projector 1 including, when the first personal computer 600 is connected to the projector 1 via the first image cable CP1 and a control cable is connected to the first control terminal 171, determining whether the identification information input from the first control terminal 171 is the first identification information J1 or the second identification information J2, and when it is determined that the identification information is the second identification information J2, notifying a first message MG1 indicating that the control cable connected to the first control terminal 171 is invalid.

[0155] In this configuration, the control cable connected to the first control terminal 171 is, for example, any one of the first control cable CC1, the second control cable CC2, and other control cables. When the projector 1 detects that any one of the first control cable CC1, the second control cable CC2, and other control cables is connected to the first control terminal 171, it determines that the control cable is connected.

[0156] In this way, the first personal computer 600 can transmit the first identification information J1 to the projector 1 via each of the first image cable CP1 and the first control cable CC1. Also, the second personal computer 700 can transmit the second identification information J2 to the projector 1 via each of the second image cable CP2 and the second control cable CC2. Then, when the first personal computer 600 is connected to the projector 1 via the first image cable CP1 and a control cable is connected to the first control terminal 171, the projector 1 determines whether the identification information input from the first control terminal 171 is the first identification information J1 or the second identification information J2, and when it is determined that the identification information is the second identification information J2, it notifies the first message MG1 indicating that the control cable connected to the first control terminal 171 is invalid. Therefore, according to the control method for the projection system 2 of the second embodiment, the same effects as those of the control method for the projection system 2 of the first embodiment are achieved.

[0157] A control method for a projection system 2 according to a third embodiment includes a projector 1 that projects a projection image onto a projection surface 10, receives a user's operation on the projection surface 10, and generates a control signal indicating a position PS of the operation on the projection surface 10, a first personal computer 600 that is communicatively connected to the projector 1, and a second personal computer 700 that is communicatively connected to the projector 1, the first personal computer 600 being configured to transmit a first image signal indicating the projection image to the projector 1 via a first image cable CP1, receive the control signal from the projector 1 via a first control cable CC1, and be controlled based on the control signal, and the second personal computer 700 being configured to transmit a second image signal indicating the projection image to the projector 1 via a second image cable CP2, receive the control signal from the projector 1 via a second control cable CC2, and be controlled based on the control signal. a control method for a projection system 2 in which a projector 1 has a first control terminal 171 to which a first control cable CC1 is connected and a second control terminal 172 to which a second control cable CC2 is connected, the projector 1 transmits first identification information J1 via each of the first image cable CP1 and the first control terminal 171, and transmits second identification information J2 via each of the second image cable CP2 and the second control terminal 172, and a first personal computer 600, when the projector 1 is connected to the first personal computer 600 via the first image cable CP1 and the first control cable CC1 is connected to the first control terminal 171, determines whether the identification information input via the first control cable CC1 is the first identification information J1 or the second identification information J2, and when it is determined that the identification information is the second identification information J2, notifies a first message MG1 indicating that the control cable connected to the first control terminal 171 is invalid.

[0158] In this way, the projector 1 transmits the first identification information J1 via each of the first image cable CP1 and the first control terminal 171, and transmits the second identification information J2 via each of the second image cable CP2 and the second control terminal 172. Then, when the projector 1 is connected to the first personal computer 600 via the first image cable CP1 and the first control cable CC1 is connected to the first control terminal 171, the first personal computer 600 determines whether the identification information input from the first control cable CC1 is the first identification information J1 or the second identification information J2, and when it is determined that the identification information is the second identification information J2, it notifies a first message MG1 indicating that the control cable connected to the first control terminal 171 is invalid. Therefore, according to the control method for the projection system 2 of the third embodiment, the same effects as those of the control method for the projection system 2 of the first embodiment are achieved.

[0159] A control method for a projection system 2 according to a fourth embodiment includes a projector 1 that projects a projection image onto a projection surface 10, receives a user's operation on the projection surface 10, and generates a control signal indicating a position PS of the operation on the projection surface 10, a first personal computer 600 that is communicatively connected to the projector 1, and a second personal computer 700 that is communicatively connected to the projector 1, the first personal computer 600 being configured to transmit a first image signal indicating the projection image to the projector 1 via a first image cable CP1, receive the control signal from the projector 1 via a first control cable CC1, and be controlled based on the control signal, the second personal computer 700 being configured to transmit a second image signal indicating the projection image to the projector 1 via a second image cable CP2, receive the control signal from the projector 1 via a second control cable CC2, and be controlled based on the control signal, the projector 1 having a first control terminal 171 to which the first control cable CC1 and the second control cable CC2 are connected, and a second control terminal 172 to which the second control cable CC2 are connected, A method for controlling a projection system 2 having a terminal 172, the projector 1 transmits first identification information J1 via a first control terminal 171 and transmits second identification information J2 via a second control terminal 172, the first personal computer 600 is capable of transmitting the first identification information J1 to the projector 1 via a first image cable CP1 when it receives the first identification information J1, and is capable of transmitting the second identification information J2 to the projector 1 via the first image cable CP1 when it receives the second identification information J2, and the second personal computer 70 when the projector 1 receives the first identification information J1, the projector 1 is capable of transmitting the first identification information J1 to the projector 1 via the second image cable CP2, and when the projector 1 receives the second identification information J2, the projector 1 is capable of transmitting the second identification information J2 to the projector 1 via the second image cable CP2, and when the projector 1 is connected to the first control terminal 171 via the first control cable CC1 and an image cable is connected to the projector 1, the projector 1 determines whether the identification information input from the image cable is the first identification information J1 or the second identification information J2;When it is determined that the identification information is the second identification information J2, a first message MG1 is notified indicating that the image cable connected to the projector 1 is unauthorized.

[0160] In this configuration, the image cable connected to the projector 1 is, for example, any one of the first image cable CP1, the second image cable CP2, and other image cables. When the projector 1 detects that any one of the first image cable CP1, the second image cable CP2, and other image cables is connected to the projector 1, the projector 1 determines that the image cable is connected.

[0161] In this way, the projector 1 transmits the first identification information J1 via the first control terminal 171, and transmits the second identification information J2 via the second control terminal 172. Furthermore, when the first personal computer 600 receives the first identification information J1, it can transmit the first identification information J1 to the projector 1 via the first image cable CP1, and when the first personal computer 600 receives the second identification information J2, it can transmit the second identification information J2 to the projector 1 via the first image cable CP1. Furthermore, when the second personal computer 700 receives the first identification information J1, it can transmit the first identification information J1 to the projector 1 via the second image cable CP2, and when the second identification information J2 is received, it can transmit the second identification information J2 to the projector 1 via the second image cable CP2. When the projector 1 is connected to the first control terminal 171 via the first control cable CC1 and an image cable is connected to the projector 1, the projector 1 determines whether the identification information input from the image cable is the first identification information J1 or the second identification information J2, and if it is determined that the identification information is the second identification information J2, it issues a first message MG1 indicating that the control cable connected to the first control terminal 171 is invalid. Therefore, according to the control method for the projection system 2 of the fourth embodiment, the same effects as those of the control method for the projection system 2 of the first embodiment are achieved.

[0162] [8. Transformation] The above-described embodiment is a preferred embodiment of the present invention, however, the present invention is not limited to this embodiment and can be embodied in various modified forms without departing from the spirit of the present invention.

[0163] In this embodiment, a case will be described in which the "first information processing device" is the first personal computer 600 and the "second information processing device" is the second personal computer 700, but the present disclosure is not limited to this. Each of the "first information processing device" and the "second information processing device" may be, for example, a notebook computer.

[0164] In this embodiment, the first image communication interface 160, the third image communication interface 660, and the fourth image communication interface 760 communicate in accordance with the HDMI (registered trademark) standard, but the present disclosure is not limited thereto. The first image communication interface 160, the third image communication interface 660, and the fourth image communication interface 760 may communicate in accordance with, for example, the DVI (registered trademark) (Digital Visual Interface) standard.

[0165] In this embodiment, the first control communication interface 170, the third control communication interface 670, and the fourth control communication interface 770 perform communication in accordance with the USB (registered trademark) standard, but the present disclosure is not limited thereto. The first control communication interface 170, the third control communication interface 670, and the fourth control communication interface 770 may perform communication in accordance with, for example, the micro USB (registered trademark) standard.

[0166] In this embodiment, a configuration has been described in which the projector body 100 includes the irradiation unit 133 and the imaging unit 135, but at least one of the irradiation unit 133 and the imaging unit 135 may be provided outside the projector body 100 as a separate device. Also, part of the functions of the first control unit 150 may be mounted on a separate device provided outside the projector body 100. When these components are provided outside the projector body 100, they may each be an independent device, or a device including two or more of these components may be used. In these cases, the whole including the separate components may be referred to as the projector.

[0167] Also, the functional units shown in FIG. 3, FIG. 4, FIG. 6, FIG. 8, and FIG. 10 show the functional configuration of each of the first control unit 150, the third control unit 650, and the fourth control unit 750, and the specific implementation form is not particularly limited. In other words, it is not necessarily necessary to implement hardware corresponding to each functional unit individually, and it is also possible to implement a configuration in which one processor executes a program to realize the functions of multiple functional units. Also, in this embodiment, some of the functions realized by software may be realized by hardware, or some of the functions realized by hardware may be realized by software. In addition, the specific detailed configuration of each of the other units of the projector body 100 can also be arbitrarily changed within the scope of the gist.

[0168] In addition, the processing units in the flowcharts shown in Figures 5, 7, 9, and 11 are divided according to the main processing contents in order to facilitate understanding of the processing of the first control unit 150, the third control unit 650, and the fourth control unit 750. There is no limitation to the manner of division or names of the processing units shown in the flowcharts shown in Figures 5, 7, 9, and 11, and the processing units can be divided into more processing units according to the processing contents, or one processing unit can be divided to include more processes. In addition, the processing order of the above flowcharts is not limited to the example shown in the figures.

[0169] Furthermore, the control method for the projection system 2 can be realized by having the first processor 150A included in the projector 1 execute the first control program PG1, the third control unit 650 of the first personal computer 600 execute the third control program PG3, and the fourth control unit 750 of the second personal computer 700 execute the fourth control program PG4. Each of the first control program PG1, the third control program PG3, and the fourth control program PG4 can also be recorded on a recording medium that is readable by a computer. As the recording medium, a magnetic or optical recording medium, or a semiconductor memory device can be used. Specifically, examples of the recording medium include portable or fixed recording media such as a flexible disk, a hard disk drive (HDD), a compact disk read only memory (CD-ROM), a digital versatile disk (DVD), a Blu-ray (registered trademark) disc, a magneto-optical disk, a flash memory, a card-type recording medium, etc. The recording medium may also be a non-volatile storage device such as a RAM, a ROM, or a HDD, which is an internal storage device provided in each of the projector main body 100, the first personal computer 600, and the second personal computer 700. In addition, at least one of the first control program PG1, the third control program PG3, and the fourth control program PG4 can be stored in a server device or the like, and the control program can be downloaded from the server device to the projector body 100, the first personal computer 600, or the second personal computer 700, thereby realizing the control method for the projection system 2.

[0170] [9. Notes] The following is a summary of this disclosure. (Supplementary Note 1) A control method for a projection system comprising: a projection device that projects a projection image onto a projection surface, receives a user's operation on the projection surface, and generates a control signal indicating a position of the operation on the projection surface; a first information processing device that is communicatively connected to the projection device and controlled based on the control signal; and a second information processing device that is communicatively connected to the projection device and controlled based on the control signal, wherein the first information processing device is configured to transmit a first image signal indicating the projection image to the projection device via a first image cable, and to receive the control signal from the projection device via a first control cable, and the second information processing device is configured to transmit a second image signal indicating the projection image to the projection device via a second image cable, and to receive the control signal from the projection device via the second control cable, and the projection device comprises a first control terminal to which the first control cable is connected, and a second control terminal to which the second control cable is connected, a first identification information input from the first control terminal of the projection device when the first information processing device is connected to the projection device via the first image cable and a control cable is connected to the first control terminal, the first identification information being transmitted to the first information processing device via the first control cable, and the second identification information being transmitted to the second information processing device via the second image cable, the first information processing device being capable of transmitting the first identification information to the projection device via the first control cable when the first information processing device receives the first identification information, and the second information processing device being capable of transmitting the second identification information to the projection device via the second control cable when the second information processing device receives the second identification information,

[0171] This allows the user to easily confirm from the first message that the control cable connected to the first control terminal is unauthorized. Therefore, the user can easily understand the reason why interactive control is not being performed normally. As a result, user convenience can be improved.

[0172] (Supplementary Note 2) The control method for a projection system according to Supplementary Note 1, wherein the projection device notifies the user by projecting the first message onto the projection surface.

[0173] This allows the user to easily view the first message. Therefore, by viewing the first message, the user can easily confirm that the control cable connected to the first control terminal is unauthorized. Therefore, the user can easily understand the reason why interactive control is not being performed normally. As a result, user convenience can be improved.

[0174] (Supplementary Note 3) A method for controlling a projection system described in Supplementary Note 1 or Supplementary Note 2, comprising the projection device notifying a second message prompting the user to connect the first control cable to the first control terminal when the identification information is determined to be the second identification information.

[0175] This allows the user to easily connect the first control cable to the first control terminal by the second message, thereby allowing the user to easily resolve the cause of the interactive control not being performed normally, thereby improving user convenience.

[0176] (Appendix 4) A method for controlling a projection system described in any one of Appendices 1 to 3, wherein the projection device includes a first image terminal to which the first image cable can be connected and a second image terminal to which the second image cable can be connected, the first identification information being first allocation information pre-assigned to the first image terminal, and the second identification information being second allocation information pre-assigned to the second image terminal.

[0177] This allows the projection device to easily generate the first identification information and the second identification information, thereby simplifying the configuration of the projection device.

[0178] (Supplementary Note 5) A projection device that projects a projection image onto a projection surface, receives a user's operation on the projection surface, and generates a control signal indicating a position of the operation on the projection surface, the projection device being communicably connected to a first information processing device and a second information processing device, the first information processing device being configured to transmit a first image signal indicating the projection image to the projection device via a first image cable, receive the control signal from the projection device via a first control cable, and be controlled based on the control signal, and when first identification information is received from the projection device, the first information processing device being configured to transmit the first identification information to the projection device via the first control cable, the second information processing device being configured to transmit a second image signal indicating the projection image to the projection device via a second image cable, receive the control signal from the projection device via a second control cable, and be controlled based on the control signal, and when second identification information is received from the projection device, the second information processing device being configured to transmit a first control terminal to which the first control cable is connected and a second control terminal to which the second control cable is connected, and a processor, the processor being capable of: transmitting the first identification information to the first information processing device via the first image cable; transmitting the second identification information to the second information processing device via the second image cable; determining whether the identification information input from the first control terminal is the first identification information or the second identification information, when the first information processing device is connected to the projection device via the first image cable and a control cable is connected to the first control terminal; and, when it is determined that the identification information is the second identification information, notifying a first message indicating that the control cable connected to the first control terminal is invalid.

[0179] As a result, the projection device described in Supplementary Note 5 has the same effects as the projection system control method described in Supplementary Note 1.

[0180] (Supplementary Note 6) A projection device that projects a projection image onto a projection surface, receives a user's operation on the projection surface, and generates a control signal indicating a position of the operation on the projection surface, a first information processing device communicatively connected to the projection device, and a second information processing device communicatively connected to the projection device, wherein the first information processing device is configured to transmit a first image signal indicating the projection image to the projection device via a first image cable, receive the control signal from the projection device via a first control cable, and be controlled based on the control signal, and the second information processing device is configured to transmit a second image signal indicating the projection image to the projection device via a second image cable, receive the control signal from the projection device via the second control cable, and be controlled based on the control signal, and the projection device is a first information processing device to which the first control cable and the second control cable are connected. A control method for a projection system comprising a control terminal and a second control terminal, wherein the first information processing device is capable of transmitting first identification information to the projection device via each of the first image cable and the first control cable, and the second information processing device is capable of transmitting second identification information to the projection device via each of the second image cable and the second control cable, the projection device including, when the first information processing device is connected to the projection device via the first image cable and a control cable is connected to the first control terminal, determining whether the identification information input from the first control terminal is the first identification information or the second identification information, and when it is determined that the identification information is the second identification information, reporting a first message indicating that the control cable connected to the first control terminal is invalid.

[0181] As a result, the projection system control method described in Supplementary Note 6 has the same effects as the projection system control method described in Supplementary Note 1.

[0182] (Supplementary Note 7) A projection device that projects a projection image onto a projection surface, receives a user's operation on the projection surface, and generates a control signal indicating a position of the operation on the projection surface, a first information processing device communicatively connected to the projection device, and a second information processing device communicatively connected to the projection device, wherein the first information processing device is configured to transmit a first image signal indicating the projection image to the projection device via a first image cable, receive the control signal from the projection device via a first control cable, and be controlled based on the control signal, and the second information processing device is configured to transmit a second image signal indicating the projection image to the projection device via a second image cable, receive the control signal from the projection device via the second control cable, and be controlled based on the control signal, and the projection device is connected to a first information processing device connected to the first control cable. a first control terminal to which the second control cable is connected, and a second control terminal to which the second control cable is connected, wherein the projection device transmits first identification information via the first image cable and the first control terminal, and transmits second identification information via the second image cable and the second control terminal, and the first information processing device, when the projection device is connected to the first information processing device via the first image cable and the first control cable is connected to the first control terminal, determines whether the identification information input via the first control cable is the first identification information or the second identification information, and when it is determined that the identification information is the second identification information, notifies a first message indicating that the control cable connected to the first control terminal is invalid.

[0183] As a result, the projection system control method described in Supplementary Note 7 has the same effects as the projection system control method described in Supplementary Note 1.

[0184] (Supplementary Note 8) A control method for a projection system comprising: a projection device that projects a projection image onto a projection surface, receives a user's operation on the projection surface, and generates a control signal indicating a position of the operation on the projection surface; a first information processing device communicably connected to the projection device; and a second information processing device communicably connected to the projection device, wherein the first information processing device is configured to transmit a first image signal indicating the projection image to the projection device via a first image cable, receive the control signal from the projection device via a first control cable, and be controlled based on the control signal; the second information processing device is configured to transmit a second image signal indicating the projection image to the projection device via a second image cable, receive the control signal from the projection device via a second control cable, and be controlled based on the control signal; and the projection device comprises a first control terminal to which the first control cable is connected, and a second control terminal to which the second control cable is connected, wherein the projection device transmits first identification information via the first control terminal, and generates a control signal indicating the position of the operation on the projection surface; and transmitting second identification information to the projection device via the first image cable, when the first information processing device receives the first identification information, and transmitting the second identification information to the projection device via the first image cable when the second information processing device receives the second identification information, and transmitting the first identification information to the projection device via the second image cable when the second information processing device receives the first identification information, and transmitting the second identification information to the projection device via the second image cable when the second information processing device receives the first identification information, and

[0185] As a result, the projection system control method described in Supplementary Note 8 has the same effects as the projection system control method described in Supplementary Note 1. [Explanation of symbols]

[0186] 1...projector (projection device), 2...projection system, 10...projection surface, 50...first indicator, 70...second indicator, 100...projector body, 110...image storage unit, 120...projection unit, 150...first control unit, 150A...first processor, 150B...first memory, 151...transmission unit, 152...reception unit, 153...determination unit, 154...notification unit, 160...first image communication interface, 161...first image terminal, 162...second image terminal, 170...first control communication interface, 171...first control terminal, 172...second control terminal, 600...first personal computer (first information processing device), 650...third control unit, 650A...third processor, 650B...third memory, 655...transmission unit, 660...third image communication interface interface, 661...third image terminal, 670...third control communication interface, 671...third control terminal, 700...second personal computer (second information processing device), 750...fourth control unit, 750A...fourth processor, 750B...fourth memory, 755...transfer unit, 760...fourth image communication interface, 761...fourth image terminal, 770...fourth control communication interface, 771...fourth control terminal, CC1...first control cable, CC2...second control cable, CP1...first image cable, CP2...second image cable, J1...first identification information, J2...second identification information, MG1...first message, MG2...second message, PG1...first control program, PG3...third control program, PG4...third control program.

Claims

1. a projection device that projects a projection image onto a projection surface, receives a user's operation on the projection surface, and generates a control signal indicating a position of the operation on the projection surface; a first information processing device that is communicatively connected to the projection device and controlled based on the control signal; a second information processing device that is communicatively connected to the projection device and controlled based on the control signal; the first information processing device is configured to transmit a first image signal indicating the projection image to the projection device via a first image cable, and to receive the control signal from the projection device via a first control cable; the second information processing device is configured to transmit a second image signal indicating the projection image to the projection device via a second image cable, and to receive the control signal from the projection device via a second control cable; a projection system control method, the projection device including a first control terminal to which the first control cable is connected and a second control terminal to which the second control cable is connected, the method comprising: the projection device is capable of transmitting first identification information to the first information processing device via the first image cable, and is capable of transmitting second identification information to the second information processing device via the second image cable; when the first information processing device receives the first identification information, the first information processing device is capable of transmitting the first identification information to the projection device via the first control cable; when the second information processing device receives the second identification information, the second information processing device is capable of transmitting the second identification information to the projection device via the second control cable; The projection device is determining whether identification information input from the first control terminal is the first identification information or the second identification information when the first information processing device is connected to the projection device via the first image cable and a control cable is connected to the first control terminal; when it is determined that the identification information input from the first control terminal is the second identification information, notifying a first message indicating that the control cable connected to the first control terminal is unauthorized; A method for controlling a projection system, comprising:

2. the projection device notifies the user by projecting the first message onto the projection surface. The method of controlling a projection system according to claim 1 .

3. the projection device notifying a second message prompting the user to connect the first control cable to the first control terminal when the identification information is determined to be the second identification information; A method for controlling a projection system according to claim 1 or 2.

4. the projection device includes a first image terminal to which the first image cable can be connected and a second image terminal to which the second image cable can be connected; the first identification information is first allocation information that is assigned in advance to the first image terminal, The second identification information is second allocation information that is assigned in advance to the second image terminal. The method of controlling a projection system according to claim 1 .

5. 1. A projection device that projects a projection image onto a projection surface, receives a user's operation on the projection surface, and generates a control signal indicating a position of the operation on the projection surface, A first information processing device and a second information processing device are communicatively connected to each other, The first information processing device is a first image signal indicating the projection image is transmitted to the projection device via a first image cable, the control signal is received from the projection device via a first control cable, and the projection device is controlled based on the control signal; when first identification information is received from the projection device, the first identification information is transmitted to the projection device via the first control cable; The second information processing device is a second image signal indicating the projection image is transmitted to the projection device via a second image cable, the control signal is received from the projection device via a second control cable, and the projection device is controlled based on the control signal; when second identification information is received from the projection device, the second identification information is transmitted to the projection device via the second control cable; the projection device includes a first control terminal to which the first control cable is connected, a second control terminal to which the second control cable is connected, and a processor; The processor, transmitting the first identification information to the first information processing device via the first image cable; transmitting the second identification information to the second information processing device via the second image cable; determining whether identification information input from the first control terminal is the first identification information or the second identification information when the first information processing device is connected to the projection device via the first image cable and a control cable is connected to the first control terminal; when it is determined that the identification information is the second identification information, notifying a first message indicating that the control cable connected to the first control terminal is unauthorized; A projection device capable of executing the above.

6. a projection device that projects a projection image onto a projection surface, receives a user's operation on the projection surface, and generates a control signal indicating a position of the operation on the projection surface; a first information processing device communicably connected to the projection device; a second information processing device connected to the projection device so as to be capable of communicating with the projection device; the first information processing device is configured to transmit a first image signal indicating the projection image to the projection device via a first image cable, receive the control signal from the projection device via a first control cable, and be controlled based on the control signal; the second information processing device is configured to transmit a second image signal indicating the projection image to the projection device via a second image cable, receive the control signal from the projection device via a second control cable, and be controlled based on the control signal; a projection system control method, the projection device including a first control terminal to which the first control cable is connected and a second control terminal to which the second control cable is connected, the method comprising the steps of: the first information processing device is capable of transmitting first identification information to the projection device via each of the first image cable and the first control cable; the second information processing device is capable of transmitting second identification information to the projection device via each of the second image cable and the second control cable; The projection device is determining whether identification information input from the first control terminal is the first identification information or the second identification information when the first information processing device is connected to the projection device via the first image cable and a control cable is connected to the first control terminal; when it is determined that the identification information is the second identification information, notifying a first message indicating that the control cable connected to the first control terminal is unauthorized; A method for controlling a projection system, comprising:

7. a projection device that projects a projection image onto a projection surface, receives a user's operation on the projection surface, and generates a control signal indicating a position of the operation on the projection surface; a first information processing device communicably connected to the projection device; a second information processing device connected to the projection device so as to be capable of communicating with the projection device; the first information processing device is configured to transmit a first image signal indicating the projection image to the projection device via a first image cable, receive the control signal from the projection device via a first control cable, and be controlled based on the control signal; the second information processing device is configured to transmit a second image signal indicating the projection image to the projection device via a second image cable, receive the control signal from the projection device via a second control cable, and be controlled based on the control signal; a projection system control method, the projection device including a first control terminal to which the first control cable is connected and a second control terminal to which the second control cable is connected, the method comprising: The projection device is Transmitting first identification information via each of the first image cable and the first control terminal; Transmitting second identification information via each of the second image cable and the second control terminal; The first information processing device is determining whether identification information input via the first control cable is the first identification information or the second identification information when the projection device is connected to the first information processing device via the first image cable and the first control cable is connected to the first control terminal; when it is determined that the identification information is the second identification information, notifying a first message indicating that the control cable connected to the first control terminal is unauthorized; A method for controlling a projection system, comprising:

8. a projection device that projects a projection image onto a projection surface, receives a user's operation on the projection surface, and generates a control signal indicating a position of the operation on the projection surface; a first information processing device communicably connected to the projection device; a second information processing device connected to the projection device so as to be capable of communicating with the projection device; the first information processing device is configured to transmit a first image signal indicating the projection image to the projection device via a first image cable, receive the control signal from the projection device via a first control cable, and be controlled based on the control signal; the second information processing device is configured to transmit a second image signal indicating the projection image to the projection device via a second image cable, receive the control signal from the projection device via a second control cable, and be controlled based on the control signal; a projection system control method, the projection device including a first control terminal to which the first control cable is connected and a second control terminal to which the second control cable is connected, the method comprising: the projection device transmits first identification information via the first control terminal and transmits second identification information via the second control terminal; when the first information processing device receives the first identification information, the first information processing device is capable of transmitting the first identification information to the projection device via the first image cable, and when the first information processing device receives the second identification information, the first information processing device is capable of transmitting the second identification information to the projection device via the first image cable; when the second information processing device receives the first identification information, the second information processing device is capable of transmitting the first identification information to the projection device via the second image cable, and when the second information processing device receives the second identification information, the second information processing device is capable of transmitting the second identification information to the projection device via the second image cable; The projection device is determining whether identification information input via an image cable is the first identification information or the second identification information when the projection device is connected to the first control terminal via the first control cable and an image cable is connected to the projection device; when it is determined that the identification information is the second identification information, notifying a first message indicating that the image cable connected to the projection device is unauthorized; A method for controlling a projection system, comprising:

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