Image display device and image display system

Abstract

Image display device and image display system. In the event of a failure of the upstream device in the daisy chain, the impact on the downstream device is suppressed. The projector (20) includes a projection device (25), a power supply device (26), a communication device (23), a first processing unit (221) for controlling the power supply device (26), a second processing unit (222) for controlling the projection device (25), and a third processing unit (223) for controlling the communication device (23). The communication device (23) includes a first input / output IF (231) and a second input / output IF (232). The third processing unit (223) performs the following: detecting the connection between the computer (10) that outputs image data (112) and the first input / output IF (231); acquiring the image data (112) output by the computer (10); and outputting the image data (112) from the second input / output IF (232) to the display (30).

Description

Technical Field

[0001] This invention relates to image display devices and image display systems. Background Technology

[0002] Display systems are known to connect multiple projectors or displays to a source device and display images. For example, Patent Document 1 discloses a display system in which a source device, a first projector, and a second projector are connected in a daisy-chain manner. That is, in the display system of Patent Document 1, the source device is interconnected with the first projector, and the first projector is interconnected with the second projector.

[0003] Patent Document 1: Japanese Patent Application Publication No. 2020-182049

[0004] However, in the technology described in Patent Document 1, the source device and the second projector are not directly connected. The processing unit of the first projector performs the following function: acquiring image data from the source device and outputting it to the second projector. Therefore, it is possible that if the processing unit of the first projector malfunctions, neither the image projected by the first projector nor the image projected by the second projector will be output. Summary of the Invention

[0005] To address the aforementioned issues, one embodiment of the image display apparatus disclosed herein includes: a projection device; a power supply device; a communication device having a first interface and a second interface; a first control circuit that controls the power supply device; a second control circuit that controls the projection device and is different from the first control circuit; and a third control circuit that controls the communication device and is different from both the first and second control circuits, wherein the third control circuit performs the following processing: detecting whether an image output device that outputs image data is connected to the first interface; acquiring the image data output by the image output device; and outputting the image data from the second interface to an external display device.

[0006] To address the aforementioned issues, one embodiment of the image display system disclosed herein includes: a source device; a first display device connected to the source device; and a second display device connected to the first display device. The second display device outputs second specification information related to image display of the second display device to the first display device. The first display device outputs both the first specification information and the second specification information related to image display of the first display device to the source device. Based on the first specification information and the second specification information, the source device determines the format of image data that can be displayed by the first and second display devices. The source device outputs the determined image data to the first display device, and the first display device outputs the image data to the second display device.

[0007] To address the aforementioned issues, one embodiment of the image display system disclosed herein comprises: a source device; a first display device connected to the source device; and a second display device connected to the first display device, wherein the second display device outputs second specification information relating to image display of the second display device to the first display device, the first display device generates third specification information based on the first specification information and the second specification information relating to image display of the first display device, the first display device outputs the third specification information to the source device, the source device determines the form of image data that can be displayed by the first display device and the second display device based on the third specification information, the source device outputs image data based on the third specification information to the first display device, and the first display device outputs image data based on the third specification information to the second display device. Attached Figure Description

[0008] Figure 1 This is a structural diagram of the image display system according to the first embodiment.

[0009] Figure 2 This is a diagram showing an example of the configuration of each element in the image display system 1 according to the first embodiment.

[0010] Figure 3 It is shown Figure 1 A block diagram illustrating the structure of a computer.

[0011] Figure 4 It is shown Figure 1 A block diagram illustrating the structure of a projector.

[0012] Figure 5 It is shown Figure 1 A block diagram illustrating the structure of a display.

[0013] Figure 6 It is shown Figure 1 The timing diagram shows the power-on process of the projector.

[0014] Figure 7 It is shown Figure 1 The timing diagram of the output actions of the image data of the image display system.

[0015] Figure 8 This is a timing diagram showing the power-on operation of the projector involved in Modification Example 1.

[0016] Figure 9 This is a timing diagram showing the output operation of image data of the image display system involved in Modification Example 2.

[0017] Figure 10 This is a timing diagram showing the output operation of image data of the image display system involved in Modification Example 3.

[0018] Label Explanation

[0019] 1: Image display system; 10: Computer; 20: Projector; 23: Communication device; 25: Projection device; 26: Power supply device; 30: Display; 112: Image data; 212: First specification information; 312: Second specification information; 221: First processing device; 222: Second processing device; 223: Third processing device; 231: First input / output IF; 232: Second input / output IF. Detailed Implementation

[0020] Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings. Furthermore, the dimensions and scales of the parts in the drawings may differ from actual dimensions, and some parts are shown schematically for ease of understanding. Moreover, unless otherwise specified in the following description, the scope of the present invention is not limited to these embodiments.

[0021] 1. First Implementation Method

[0022] 1.1. Overview of Image Display Systems

[0023] The following is for reference Figures 1 to 7 The outline of the image display system 1 according to the first embodiment will be described.

[0024] Figure 1This is a structural diagram of the image display system 1 according to the first embodiment. The image display system 1 includes a computer 10, a projector 20, and a display 30. The computer 10 includes a communication device 13. The communication device 13 includes a first input / output IF 131 and a second input / output IF 132. The projector 20 includes a communication device 23. The communication device 23 includes a first input / output IF 231 and a second input / output IF 232. The display 30 includes a communication device 33. The communication device 33 includes a first input / output IF 331 and a second input / output IF 332. Here, the first input / output IF 231 is an example of a first interface, and the second input / output IF 232 is an example of a second interface.

[0025] Computer 10 and projector 20 are interconnected via a first communication cable 41. Projector 20 and monitor 30 are interconnected via a second communication cable 42. Therefore, computer 10, projector 20, and monitor 30 are connected in a so-called daisy-chain manner.

[0026] The first communication cable 41 and the second communication cable 42 are cables for transmitting image data, control signals, notification signals, and power voltage. For example, the first communication cable 41 and the second communication cable 42 are HDMI (registered trademark) cables.

[0027] Computer 10 stores first image data that forms the basis of the projected image projected by projector 20, and second image data that forms the basis of the displayed image displayed on monitor 30. Computer 10 sends the first image data and the second image data to projector 20.

[0028] More specifically, the first image data and the second image data output from the computer 10 are input to the projector 20 via the first communication cable 41. The first image data input to the projector 20 is stored in the storage device of the projector 20. The second image data input to the projector 20 is relayed by the projector 20 and input to the display 30 via the second communication cable 42.

[0029] Additionally, when the computer 10 and the projector 20 are connected by the first communication cable 41, a connection notification signal is sent from the projector 20 to the computer 10. When the projector 20 and the monitor 30 are connected by the second communication cable 42, a connection notification signal is sent from the monitor 30 to the projector 20.

[0030] 1.2. Configuration Example of Image Display System 1

[0031] Figure 2 This diagram illustrates an example configuration of the various elements in the image display system 1 according to the first embodiment. Furthermore, the elements in the image display system 1 are installed in a school classroom 70, but... Figure 2In order to make the configuration example easier to understand, part of the ceiling and walls in classroom 70 have been omitted.

[0032] Screen 50 is mounted, for example, on the wall 70-1 at the front of classroom 70. Projector 20 is mounted on the ceiling of classroom 70 and projects images onto screen 50. Monitor 30 is mounted at the rear of classroom 70. Speaker 60-1 is mounted on wall 70-1, and speaker 60-2 is mounted on the wall 70-2 to the right of classroom 70.

[0033] User U1 is, for example, a school teacher. User U1 operates the computer 10 placed at the front of classroom 70. User U2 is, for example, multiple students belonging to group 1, and user U3 is, for example, multiple students belonging to group 2. User U2, belonging to group 1, watches and listens to the first image content projected from projector 20 onto screen 50. User U3, belonging to group 2, watches and listens to the second image content displayed on monitor 30.

[0034] In this embodiment, the first image content and the second image content are the same. Furthermore, in this embodiment, the specifications related to the image display of the projector 20 and the specifications related to the image display of the display 30 are the same. Therefore, in this embodiment, the first image data and the second image data are the same image data.

[0035] 1.3. Structure of Computer 10

[0036] Figure 3 It is shown Figure 1 A block diagram illustrating the structure of a computer 10. The computer 10 includes a storage device 11, a processing device 12, a communication device 13, a display device 14, and an input device 15. The various components of the computer 10 are interconnected via one or more buses for communicating information. The computer 10 is an example of an image output device and a source device.

[0037] Storage device 11 stores various types of information. Storage device 11 may be configured to include, for example, volatile memory such as RAM and non-volatile memory such as ROM. Here, RAM is an abbreviation for Random Access Memory. ROM is an abbreviation for Read Only Memory. Control program 111, image data 112, etc., are stored in storage device 11. The volatile memory of storage device 11 is used by processing device 12 as the working area 113 of processing device 12. Control program 111 is a program that controls the overall computer 10.

[0038] Furthermore, part or all of the storage device 11 may be located on an external storage device, an external server, or the like. In addition, part or all of the various information stored in the storage device 11 may be pre-stored in the storage device 11 or obtained from an external storage device, an external server, or the like.

[0039] The processing unit 12 controls the operation of the computer 10. The processing unit 12 functions as a receiving unit 121, a transmitting unit 122, an image transformation unit 123, and a display control unit 124. The processing unit 12 is configured to include one or more CPUs. However, the processing unit 12 may replace a CPU or, in addition to a CPU, include programmable logic devices such as FPGAs or ASICs. Here, CPU is an abbreviation for Central Processing Unit, FPGA is an abbreviation for Field-Programmable Gate Array, and ASIC is an abbreviation for Application Specific Integrated Circuit.

[0040] The processing device 12 reads the control program 111 from the storage device 11 and executes the read control program 111. The processing device 22 functions as a receiving unit 121, a transmitting unit 122, an image transformation unit 123, and a display control unit 124 by executing the control program 111.

[0041] The receiving unit 121 receives various signals output from the projector 20 and the display 30 via the communication device 13.

[0042] The transmitting unit 122 transmits image data 112 to the projector 20 via the communication device 13.

[0043] The image transformation unit 123 transforms the resolution, frame rate, and other parameters of the image data 112 as needed. For example, the image transformation unit 123 transforms the format of the image data 112, such as the resolution and frame rate, to suit the specifications of the projector 20 or the display 30.

[0044] The display control unit 124 controls the display device 14 to display images or text.

[0045] The communication device 13 is hardware that serves as a transceiver for communicating with other devices. The communication device 13 is also referred to as a network device, network controller, network interface card (NIC), communication module, etc. The communication device 13 may also include a connector for wired connection and an interface circuit corresponding to that connector. Additionally, the communication device 13 may also include a wireless communication interface. Examples of wired connectors and interface circuits that conform to HDMI (High-Definition Multimedia Interface; registered trademark), DisplayPort (registered trademark), wired LAN, IEEE 1394, USB, etc., can be listed. Examples of wireless communication interfaces that conform to wireless LAN and Bluetooth (registered trademark), etc., can be listed. The communication device 13 communicates with the projector 20. In this embodiment, HDMI (registered trademark) will be used as an example of the communication interface.

[0046] Display device 14 is a device that displays images and character information. Display device 14 displays various images based on the control of processing device 12. For example, various display panels such as liquid crystal panels and organic EL (Electro Luminescence) panels are suitable for use as display device 14.

[0047] Input device 15 accepts operations from the user. For example, input device 15 may be configured to include a keyboard, touchpad, touch panel, mouse, or other pointing devices. In this case, if input device 15 is configured to include a touch panel, it may also function as display device 14.

[0048] 1.4. Structure of the Projector

[0049] Figure 4 It is shown Figure 1 A block diagram illustrating the structure of a projector 20. The projector 20 includes a storage device 21, a processing device 22, a communication device 23, an operation device 24, a projection device 25, and a power supply device 26. The various components of the projector 20 are interconnected via one or more buses for information communication. The projector 20 is an example of an image display device and a first display device.

[0050] Storage device 21 stores various information. Storage device 21 may be configured to include, for example, volatile memory such as RAM and non-volatile memory such as ROM. Control program 211, first specification information 212, etc., are stored in storage device 21. The volatile memory of storage device 21 is used by processing device 22 as the working area 213 of processing device 22. Control program 211 is a program that controls the projector 20 as a whole. First specification information 212 contains information related to the resolution, frame rate, color depth, color gamut, and contrast of projection device 25.

[0051] Resolution indicates the number of pixels in an image displayed on a display device. Higher resolution results in a more detailed image. Frame rate indicates the number of frames per second. A higher frame rate results in a smoother image. Color depth indicates the resolution of each pixel in the image. Color depth is also known as deep color. A higher color depth value results in a smoother color transition. Color gamut indicates the width of the color range that can be processed. Standards include BT.601, BT.709, BT.2020, and BT.2100. A higher standard value allows for a wider range of colors to be processed. Contrast ratio indicates the difference in brightness between the darkest and brightest parts of an image. Contrast ratio standards include SDR (Standard Dynamic Range), HDR (High Dynamic Range), HLG (Hybrid Log-Gamma), and HDR10+. The difference in brightness increases in the order SDR, HDR, and HDR10+, resulting in a more vibrant image. HLG has the same contrast ratio as HDR.

[0052] Furthermore, part or all of the storage device 21 may be located on an external storage device, an external server, or the like. In addition, part or all of the various information stored in the storage device 21 may be pre-stored in the storage device 21 or obtained from an external storage device, an external server, or the like.

[0053] The processing unit 22 controls the operation of the projector 20. The processing unit 22 includes a first processing unit 221, a second processing unit 222, a third processing unit 223, and a fourth processing unit 224. Each of the first processing unit 221, the second processing unit 222, the third processing unit 223, and the fourth processing unit 224 is configured to include one or more CPUs. However, the first processing unit 221, the second processing unit 222, the third processing unit 223, and the fourth processing unit 224 may replace the CPU, or may include programmable logic devices such as FPGAs or ASICs in addition to CPUs.

[0054] The first processing unit 221 functions as a power control unit. Power control refers to controlling the power supply device 26. The second processing unit 222 functions as a projection control unit. Projection control refers to controlling the projection device 25. The third processing unit 223 functions as a communication control unit. Communication control refers to controlling the communication device 23. The fourth processing unit 224 functions as an operation control unit. Operation control refers to controlling the operation device 24.

[0055] Furthermore, the first processing device 221, the second processing device 222, the third processing device 223, and the fourth processing device 224 are each configured individually. Specifically, for example, the first processing device 221, the second processing device 222, the third processing device 223, and the fourth processing device 224 are each mounted as a separate chip on a substrate.

[0056] The processing device 22 reads the control program 211 from the storage device 21 and executes the read control program 211. By executing the control program 211, the processing device 22 functions as a power control unit, a projection control unit, a communication control unit, and an operation control unit.

[0057] The communication device 23 is hardware that serves as a transceiver for communicating with other devices. The communication device 23 is also referred to as a network device, network controller, network interface card (NIC), communication module, etc. The communication device 23 has a connector for wired connection and an interface circuit corresponding to the connector. Alternatively, the communication device 23 may also have a wireless communication interface. Examples of wired connectors and interface circuits include those conforming to HDMI (registered trademark), DisplayPort (registered trademark), wired LAN, IEEE 1394, USB, etc. Examples of wireless communication interfaces include those conforming to wireless LAN and Bluetooth (registered trademark). The communication device 23 communicates with the computer 10 and the display 30.

[0058] The communication device 23 includes a first input / output IF (interface) 231 and a second input / output IF 232. The first input / output IF 231 includes an input / output connector for wired connection and interface circuitry corresponding to the input / output connector. The second input / output IF 232 includes an input / output connector for wired connection and interface circuitry corresponding to the input / output connector.

[0059] The operating device 24 is an input interface that receives input operations from the user U1 for the projector 20. The operating device 24 may have, for example, operating buttons provided in the housing of the projector 20. The operating device 24 outputs information identifying the pressed operating button to the processing device 22. Thus, the content of the user U1's input operation to the operating device 24 is output to the processing device 22. Therefore, the content of the user U1's input operation to the operating device 24 is transmitted to the processing device 22.

[0060] Alternatively, the operating device 24 may have a touch panel instead of operating buttons. In this case, the operating device 24 outputs data indicating the detected touch position to the processing device 22. Alternatively, the operating device 24 may also be a remote control device independent of the projector 20's housing.

[0061] The projection device 25 projects projected light. Additionally, the projection device 25 includes a light source (not shown), a light modulator 251, and a projection lens 252. The light source may include a halogen lamp, a xenon lamp, an ultra-high pressure mercury lamp, an LED, or a laser light source. The light modulator 251 includes one or more liquid crystal panels. Alternatively, the light modulator 251 may include a DMD instead of a liquid crystal panel.

[0062] The light modulator 251 modulates the light emitted from the light source into projection light for displaying the projected image on the screen 50 based on the signal input from the second processing device 222. Here, LED is an abbreviation for Light Emitting Diode, and DMD is an abbreviation for Digital Mirror Device. The projection lens 252 causes the projection light modulated by the light modulator 251 to form an image on the screen 50.

[0063] Under the control of the second processing unit 222, the projection device 25 projects projection light for displaying the projected image onto the screen 50. In other words, the projection device 25 projects an image based on image information input from the processing unit 22 onto the screen 50.

[0064] The power supply unit 26 supplies power to various parts of the projector 20. The supply or stop of power to various parts of the projector 20 is controlled by the first processing unit 221.

[0065] The first processing unit 221 controls the power supply unit 26.

[0066] The second processing unit 222 controls the operation of the projection device 25.

[0067] The third processing unit 223 controls the operation of the communication device 23. The third processing unit 223 detects the connection status of the computer 10 with the first input / output IF 231. The third processing unit 223 detects the connection status of the display 30 with the second input / output IF 232.

[0068] 1.5. Display Structure

[0069] Figure 5 It is shown Figure 1 A block diagram illustrating the structure of a display 30. The display 30 includes a storage device 31, a processing device 32, a communication device 33, and a display device 34. The various components of the display 30 are interconnected via one or more buses for communicating information. The display 30 is an example of an external display device and a second display device.

[0070] Storage device 31 stores various information. Storage device 31 may be configured to include, for example, volatile memory such as RAM and non-volatile memory such as ROM. Control program 311, second specification information 312, etc., are stored in storage device 31. The volatile memory of storage device 31 is used by processing device 32 as working area 313. Control program 311 is a program that controls the entire display 30. Second specification information 312 contains information related to the resolution, frame rate, color depth, color gamut, and contrast of display device 34.

[0071] Furthermore, part or all of the storage device 31 may be located on an external storage device, an external server, or the like. In addition, part or all of the various information stored in the storage device 31 may be pre-stored in the storage device 31 or obtained from an external storage device, an external server, or the like.

[0072] The processing device 32 controls the operation of the display 30. The processing device 32 functions as a receiving unit 321, a transmitting unit 322, and a display control unit 323. The processing device 32 is configured to include one or more CPUs. However, the processing device 32 may replace a CPU or, in addition to a CPU, include programmable logic devices such as FPGAs or ASICs.

[0073] The processing device 32 reads the control program 311 from the storage device 31 and executes the read control program 311. The processing device 32 functions as a receiving unit 321, a transmitting unit 322, and a display control unit 323 by executing the control program 311.

[0074] The receiving unit 321 receives image data 112 from the projector 20 via the communication device 33.

[0075] The transmitting unit 322 transmits various information to the projector 20 via the communication device 33.

[0076] The display control unit 323 displays the acquired image data 112 on the display device 34.

[0077] The communication device 33 is hardware that serves as a transceiver for communicating with other devices. The communication device 33 is also referred to as a network device, network controller, network interface card (NIC), communication module, etc. The communication device 33 may also include a connector for wired connection and an interface circuit corresponding to that connector. Additionally, the communication device 33 may also include a wireless communication interface. Examples of wired connectors and interface circuits that conform to HDMI (registered trademark), DisplayPort (registered trademark), wired LAN, IEEE 1394, USB, etc., can be listed. Examples of wireless communication interfaces that conform to wireless LAN and Bluetooth (registered trademark), etc., can be listed. The communication device 33 communicates with the projector 20. In this embodiment, HDMI (registered trademark) will be used as an example of the communication interface.

[0078] Display device 34 is a device for displaying images and character information. Display device 34 displays various images based on the control of processing device 32. For example, various display panels such as liquid crystal panels and organic EL (Electro Luminescence) panels are suitable for use as display device 34.

[0079] In addition, the display 30 may also have an input device for adjusting the image displayed on the display device 34.

[0080] 1.6. Specific Actions in Image Display System 1

[0081] Next, refer to Figures 6-7 The specific operations of the projector 20 or the image display system 1 will be explained. Furthermore, in this first embodiment, the explanation is based on the premise that the specifications related to the projection device 25 and the specifications related to the display device 34 are the same.

[0082] 1.6.1. Power-on operation of projector 20

[0083] Figure 6 It is shown Figure 1 The timing diagram shows the power-on operation of the projector 20. The operating device 24 of the projector 20 receives the power-on operation from the user U1. The power-on operation refers to the operation of the user U1 pressing the power-on button on the operating device 24.

[0084] When the power-on operation based on user U1 is accepted in step S11, the first processing device 221 outputs a first startup request to the second processing device 222 in step S12, and outputs a second startup request to the third processing device 223 in step S13.

[0085] Next, in step S14, the second processing device 222 executes the projection device startup timing sequence that starts the projection device 25.

[0086] In step S15, the second processing device 222 outputs first completion information to the first processing device 221. However, in this embodiment, a portion of the wiring of the second processing device 222 is broken, rendering it unable to output the first completion information. Therefore, the first processing device 221 cannot receive the first completion information.

[0087] In step S16, the third processing device 223 executes the communication device startup sequence that enables the communication device 23 to start.

[0088] In step S17, the third processing device 223 outputs the second completion information to the first processing device 221.

[0089] In step S18, if the first processing device 221 fails to obtain the first completion information even after a predetermined time has elapsed since the output of the first start request, it determines that there is a defect in the second processing device 222.

[0090] 1.6.2. Image data output action in image display system 1

[0091] Figure 7 It is shown Figure 1 The timing diagram shows the output actions of the image data from the image display system 1. In this example, as... Figure 1 As shown, computer 10 and projector 20 are connected to each other via a first communication cable 41, and projector 20 and monitor 30 are connected to each other via a second communication cable 42. Furthermore, in this example, the startup of computer 10, projector 20, and monitor 30 is presumably complete.

[0092] In step S21, the processing device 12 of the computer 10 detects that the projector 20 is connected to the second input / output IF 132 via the first communication cable 41.

[0093] In step S22, the third processing device 223 of the projector 20 detects the connection between the computer 10 and the first input / output IF 231 via the first communication cable 41.

[0094] In step S23, the third processing device 223 detects that the display 30 is connected to the second input / output IF 232 via the second communication cable 42.

[0095] In step S24, the processing device 32 of the display 30 detects that the projector 20 is connected to the first input / output IF 331 via the second communication cable 42.

[0096] In step S25, the processing device 12 outputs the image data 112 stored in the storage device 11 from the second input / output IF 132.

[0097] In step S26, the third processing device 223 outputs the image data 112 obtained from the first input / output IF 231 to the display 30.

[0098] In step S27, the third processing device 223 stores the acquired image data 112 in the storage device 21.

[0099] In step S28, the processing device 32 stores the image data 112 obtained from the first input / output IF 331 in the storage device 31.

[0100] In step S29, the third processing device 223 outputs image data 112 to the second processing device 222. However, a problem occurs in the second processing device 222. Assuming that no problem occurs in the second processing device 222, the second processing device 222 performs projection processing based on the projection device 25 in step S30, but in this example, the processing in step S30 is not performed.

[0101] In step S31, the processing device 32 displays the image based on the image data 112 on the display device 34.

[0102] 1.7. Effects of the first embodiment

[0103] As described above, the projector 20 according to the first embodiment includes a projection device 25, a power supply device 26, a communication device 23, a first processing device 221, a second processing device 222, and a third processing device 223. The communication device 23 includes a first input / output IF 231 and a second input / output IF 232.

[0104] The first processing unit 221 controls the power supply unit 26. The second processing unit 222 controls the projection unit 25. The second processing unit 222 is different from the first processing unit 221. The third processing unit 223 controls the communication unit 23. The third processing unit 223 is different from both the first processing unit 221 and the second processing unit 222.

[0105] The third processing device 223 performs the following processing: detecting the connection between the computer 10 that outputs image data 112 and the first input / output IF 231; acquiring the image data 112 output by the computer 10; and outputting the image data 112 to the display 30 from the second input / output IF 232.

[0106] According to this method, the first processing unit 221 for controlling the power supply device 26, the second processing unit 222 for controlling the projection device 25, and the third processing unit 223 for controlling the communication device 23 are each independently provided in the projector 20. Therefore, even if the second processing unit 222 malfunctions, the third processing unit 223 can still output image data 112 to the display 30, thus suppressing the impact of malfunctions in the projector 20 on the display 30.

[0107] In addition, the first processing device 221, the second processing device 222 and the third processing device 223 are each configured separately.

[0108] According to this method, even if any one of the processing devices fails, the first processing device 221, the second processing device 222, and the third processing device 223 are not easily affected by each other's failures.

[0109] Furthermore, although this embodiment is a system used by teachers in classrooms or schools to guide students, the use of the image display system 1 is not limited to this. Additionally, while this embodiment combines one projector and one monitor, a projector can be used instead of a monitor, and vice versa.

[0110] In addition, in this embodiment, HDMI (registered trademark) is used as the communication interface for daisy-chaining, but other communication interfaces that can communicate via daisy-chaining, such as DisplayPort (registered trademark) and IEEE1394, can also be used.

[0111] 2. Variations

[0112] This invention is not limited to the embodiments described above, and various modifications can be made within the scope of this invention. Specific modifications are illustrated below. Furthermore, two or more modifications selected from the following examples can be appropriately combined without contradiction. In addition, in the modifications illustrated below, elements with the same function or effect as those described in the preceding embodiments are represented by the same reference numerals used in the above description, and their detailed descriptions are appropriately omitted.

[0113] 2.1. Variation Example 1

[0114] In the above embodiment, a method is illustrated where projection control is not performed due to a malfunction of the second processing device 222. However, in the above embodiment, power is continuously supplied from the power supply device 26 to the second processing device 222 and the projection device 25. In contrast, in Modification 1, the power supply from the power supply device 26 to the malfunctioning second processing device 222 and the projection device 25, which cannot be controlled due to the malfunction of the second processing device 222, is stopped.

[0115] Figure 8 This is a timing diagram showing the power-on operation of the projector 20 involved in Modification Example 1. Furthermore, in Figure 8 In the middle, to and Figure 6 The same steps are marked as above. Figure 6 The step numbers are the same as the step numbers. The operating device 24 of the projector 20 accepts the power-on operation from user U1.

[0116] When the power-on operation based on user U1 is accepted in step S11, the first processing device 221 outputs a first startup request to the second processing device 222 in step S12, and outputs a second startup request to the third processing device 223 in step S13.

[0117] Next, in step S14, the second processing device 222 executes the projection device startup timing sequence that starts the projection device 25.

[0118] In step S15, the second processing device 222 outputs first completion information to the first processing device 221. However, in this embodiment, a portion of the wiring of the second processing device 222 is broken, rendering it unable to output the first completion information. Therefore, the first processing device 221 cannot receive the first completion information.

[0119] In step S16, the third processing device 223 executes the communication device startup sequence that enables the communication device 23 to start.

[0120] In step S17, the third processing device 223 outputs the second completion information to the first processing device 221.

[0121] In step S18, if the first processing device 221 fails to obtain the first completion information even after a predetermined time has elapsed since the output of the first start request, it determines that there is a defect in the second processing device 222.

[0122] In step S19, the first processing device 221 stops supplying power to the second processing device 222.

[0123] In step S1A, the first processing device 221 stops supplying power to the projection device 25.

[0124] In the projector 20 involved in Modification 1, when the projection device 25 is unable to project an image based on image data, the first processing device 221 causes the power supply device 26 to stop supplying power to the projection device, while on the other hand, it causes the power supply device 26 to maintain the power supply to the third processing device 223 and the communication device 23.

[0125] According to this method, in the event of a malfunction in the second processing device 222, by supplying power to the communication device 23 and the third processing device 223 and stopping the power supply to the projection device 25, it is possible to suppress the power wasted in the projection device 25 and the second processing device 222, and to output image data 112 to the display 30.

[0126] 2.2. Variation Example 2

[0127] In the first embodiment, the specifications related to the projection device 25 and the specifications related to the display device 34 are the same. In the second variation, when the specifications related to the projection device 25 and the specifications related to the display device 34 are different, the computer 10, as the source device, needs to output image data according to their respective specifications. In the second variation, an example of the computer 10 determining the format of the output image data based on the specifications will be described.

[0128] The projector 20 relays the image data 112 output from the computer 10 to the display 30. Additionally, the projector 20 relays the second specification information 312 from the display 30 to the computer 10.

[0129] The third processing unit 223 detects the connection status between the display 30 and the second input / output IF 232. The third processing unit 223 acquires the second specification information 312 output by the display 30 via the second communication cable 42. The third processing unit 223 outputs the acquired second specification information 312 to the computer 10 via the first communication cable 41. Image data 112 is generated in the computer 10 based on the first specification information 212 and the second specification information.

[0130] Figure 9 This is a timing diagram showing the output operation of image data of the image display system 1 involved in Modification 2. Furthermore, in this modification, this is predicated on the complete startup of the computer 10, projector 20, and display 30.

[0131] In step S31, the processing device 12 of the computer 10 detects that the projector 20 is connected to the second input / output IF 132 via the first communication cable 41.

[0132] In step S32, the third processing device 223 of the projector 20 detects the connection of the computer 10 to the first input / output IF 231 via the first communication cable 41.

[0133] In step S33, the third processing device 223 detects that the display 30 is connected to the second input / output IF 232 via the second communication cable 42.

[0134] In step S34, the processing device 32 of the display 30 detects that the projector 20 is connected to the first input / output IF 331 via the second communication cable 42.

[0135] In step S35, the processing device 32 outputs the second specification information 312 stored in the storage device 31 to the projector 20.

[0136] In step S36, the third processing device 233 outputs the first specification information 212 and the second specification information 312 stored in the storage device 21 to the computer 10.

[0137] In step S37, the processing device 12 determines the format of the image data 112 stored in the storage device 11 based on the first specification information 212 and the second specification information 312. Specifically, the format of the image data 112 is determined according to the lower-level specification among the specifications included in the first specification information 212 and the specifications included in the second specification information 312. Here, the lower-level specification refers to a specification with relatively low resolution, relatively low frame rate, relatively low color depth, relatively narrow color gamut, or relatively low contrast, etc.

[0138] In step S38, the processing device 12 outputs the image data 112, whose format has been determined, to the projector 20.

[0139] In step S39, the third processing device 223 outputs the image data 112 obtained from the first input / output IF 231 to the display 30.

[0140] In step S40, the third processing device 223 stores the acquired image data 112 in the storage device 21.

[0141] In step S41, the processing device 32 stores the acquired image data 112 in the storage device 31.

[0142] In step S42, the third processing device 233 outputs the image data 112 stored in the storage device 21 to the second processing device 222. However, a problem occurs in the second processing device 222. Assuming that no problem occurs in the second processing device 222, the second processing device 222 performs projection processing based on the projection device 25 in step S43, but in this example, the processing in step S43 is not performed.

[0143] In step S44, the processing device 32 displays the image based on the image data 112 on the display device 34.

[0144] As explained above, the third processing device 223 performs the following processing: detecting the connection between the display 30 and the second input / output IF 232; acquiring the second specification information 312 output by the display 30; and outputting the acquired second specification information 312 to the computer 10. The form of the image data 112 is determined based on the first specification information 212 and the second specification information 312.

[0145] According to this method, by obtaining image data from computer 10 based on specification information obtained from display 30, image data with specifications suitable for display 30 can be output to display 30.

[0146] As explained above, the image display system 1 involved in Modification 2 includes a computer 10, a projector 20 connected to the computer 10, and a display 30 connected to the projector 20. The display 30 outputs second specification information 312 related to the image display of the display 30 to the projector 20. The projector 20 outputs first specification information 212 and second specification information 312 related to the image display of the projector 20 to the computer 10. Based on the first specification information 212 and the second specification information 312, the computer 10 determines the format of the specification information that can be displayed by the projector 20 and the display 30, and outputs image data in the determined format to the projector 20. The projector 20 outputs image data to the display 30.

[0147] This method automatically selects image data of suitable specifications for both the image display device and the external display device used as sink devices, and outputs it from the source device. Therefore, it improves user convenience.

[0148] Furthermore, if the first specification information 212 and the second specification information 312 are different from each other, the computer 10 determines the form of the image data 112 according to the lower specification in the specification contained in the first specification information 212 and the specification contained in the second specification information 312.

[0149] According to this method, since the image data format is made consistent with the lower-level specifications, both the projector 20 and the display 30 can project / display images more reliably.

[0150] 2.3. Variation Example 3

[0151] In Variation 2, the method by which the computer 10 determines the format of the image data based on the first specification information 212 and the second specification information 312 is shown, but the format of the image data can also be determined in the projector 20.

[0152] Figure 10 This is a timing diagram showing the output operation of image data in the image display system 1 involved in Modification 3. Furthermore, in this modification, this is predicated on the computer 10, projector 20, and display 30 having all been started.

[0153] In step S51, the processing device 12 of the computer 10 detects that the projector 20 is connected to the second input / output IF 132 via the first communication cable 41.

[0154] In step S52, the third processing device 223 of the projector 20 detects the connection of the computer 10 to the first input / output IF 231 via the first communication cable 41.

[0155] In step S53, the third processing device 223 detects that the display 30 is connected to the second input / output IF 232 via the second communication cable 42.

[0156] In step S54, the processing device 32 of the display 30 detects that the projector 20 is connected to the first input / output IF 331 via the second communication cable 42.

[0157] In step S55, the processing device 32 outputs the second specification information 312 stored in the storage device 31 to the projector 20.

[0158] In step S56, the third processing device 233 determines the third specification information based on the first specification information 212 and the second specification information 312 stored in the storage device 21. The third specification information refers to the specification information that selects the lower-level specification among the specifications included in the first specification information and the specifications included in the second specification information.

[0159] In step S57, the third processing device 233 outputs the third specification information to the computer 10.

[0160] In step S58, the processing device 12 determines the form of the image data 112 that can be displayed by the projector 20 and the display 30 based on the third specification information.

[0161] In step S59, the processing device 12 outputs the image data 112, whose format has been determined, to the projector 20.

[0162] In step S60, the third processing device 223 outputs the image data 112 obtained from the first input / output IF 231 to the display 30.

[0163] In step S61, the third processing device 223 stores the acquired image data 112 in the storage device 21.

[0164] In step S62, the processing device 32 stores the acquired image data 112 in the storage device 31.

[0165] In step S63, the third processing device 233 outputs the image data 112 stored in the storage device 21 to the second processing device 222. However, a problem occurs in the second processing device 222. Assuming that no problem occurs in the second processing device 222, the second processing device 222 performs projection processing based on the projection device 25 in step S64, but in this example, the processing in step S64 is not performed.

[0166] In step S65, the processing device 32 displays the image based on the image data 112 on the display device 34.

[0167] As explained above, the image display system 1 according to Modification 3 includes a computer 10, a projector 20 connected to the computer 10, and a display 30 connected to the projector 20. The display 30 outputs second specification information 312 related to the image display of the display 30 to the projector 20. Based on the first specification information 212 and the second specification information 312 related to the image display of the projector 20, the projector 20 generates third specification information and outputs the third specification information to the computer 10. Based on the third specification information, the computer 10 determines the form of specification information that can be displayed by the projector 20 and the display 30, and outputs image data 112 based on the third specification information to the projector 20. The projector 20 outputs image data 112 based on the third specification information to the display 30.

[0168] This method automatically selects image data of suitable specifications for both the image display device and the external display device used as the receiver, and outputs it from the source device. Therefore, it improves user convenience.

[0169] Furthermore, when the first specification information 212 and the second specification information 312 are different from each other, the projector 20 generates third specification information, which selects the lower-level specification from the specifications included in the first specification information 212 and the specifications included in the second specification information 312. The computer 10 determines the format of the image data 112 based on the third specification information.

[0170] According to this method, since the image data format is made consistent with the lower-level specifications, both the projector 20 and the display 30 can project / display images more reliably.

[0171] 2.4. Variation Example 4

[0172] In the first embodiment, if the second processing device 222 malfunctions and image projection fails in the projection device 25, the user U1 may operate the operation device 24 to stop the power supply to the projection device 25. The power supply to the projection device 25 may be stopped, for example, by pressing the sleep button on the operation device 24.

[0173] 3. Notes

[0174] The following is a summary published in this note.

[0175] 3.1. Appendix 1

[0176] The image display device described in Appendix 1 includes: a projection device; a power supply device; a communication device having a first interface and a second interface; a first control circuit that controls the power supply device; a second control circuit that controls the projection device and is different from the first control circuit; and a third control circuit that controls the communication device and is different from both the first and second control circuits. The third control circuit performs the following processing: detecting whether an image output device that outputs image data is connected to the first interface; acquiring the image data output by the image output device; and outputting the image data from the second interface to an external display device.

[0177] According to the image display device described in Appendix 1, the first control circuit for controlling the power supply device, the second control circuit for controlling the projection device, and the third control circuit for controlling the communication device are each independently provided in the image display device. Therefore, even if a malfunction occurs in the second control circuit, image data can still be output to an external display device through the third control circuit, thus suppressing the impact of malfunctions in the image display device on the external display device.

[0178] 3.2. Appendix 2

[0179] The image display device involved in Appendix 2 is, in Appendix 1, wherein the first control circuit causes the power supply device to stop supplying power to the projection device when the projection device is unable to project an image based on the image data, and on the other hand, causes the power supply device to maintain the power supply to the third control circuit and the communication device.

[0180] According to the image display device described in Appendix 2, in the event of a malfunction in the second control circuit, power is supplied to the communication device and the third control circuit, and power supply to the projection device is stopped. As a result, the power wasted in the projection device and the second control device can be suppressed, and image data can be output to an external display device.

[0181] 3.3. Appendix 3

[0182] The image display device involved in Appendix 3 is, in Appendix 1 or Appendix 2, wherein the third control circuit performs the following processing: detecting the connection between the external display device and the second interface; obtaining specification information output by the external display device; and outputting the obtained specification information to the image output device, wherein the form of the image data is determined based on the specification information.

[0183] According to the image display device described in Appendix 3, by obtaining image data determined based on specification information obtained from an external display device from an image output device, it is possible to output image data with specifications suitable for the external display device to the external display device.

[0184] 3.4. Appendix 4

[0185] The image display device referred to in Appendix 4 is such that, in any one of Appendix 1 to Appendix 3, the first control circuit, the second control circuit, and the third control circuit are each configured independently.

[0186] According to the image display device described in Appendix 4, the first control device, the second control device, and the third control device are not easily affected by each other's failures, even if any one of the control devices fails.

[0187] 3.5. Appendix 5

[0188] The image display system described in Appendix 5 includes: a source device; a first display device connected to the source device; and a second display device connected to the first display device. The second display device outputs second specification information related to the image display of the second display device to the first display device. The first display device outputs both the first specification information and the second specification information related to the image display of the first display device to the source device. Based on the first specification information and the second specification information, the source device determines the format of image data that can be displayed by the first display device and the second display device. The source device outputs the determined image data to the first display device, and the first display device outputs the image data to the second display device.

[0189] According to the image display system described in Appendix 5, image data of suitable specifications for the image display device and external display device used as the receiver is automatically selected and output from the source device. This improves user convenience.

[0190] 3.6. Appendix 6

[0191] The image display system described in Appendix 6 is one in which, in Appendix 5, the source device determines the format of the image data according to the lower-level specification among the specifications contained in the first specification information and the specifications contained in the second specification information, when the first specification information and the second specification information are different from each other.

[0192] According to the image display system described in Appendix 6, since the image data format is consistent with the lower-level specifications, both the image display device and the external display device can project / display images more reliably.

[0193] 3.7. Appendix 7

[0194] The image display system described in Appendix 7 includes: a source device; a first display device connected to the source device; and a second display device connected to the first display device, wherein the second display device outputs second specification information related to image display of the second display device to the first display device, the first display device generates third specification information based on the first specification information and the second specification information related to image display of the first display device, the first display device outputs the third specification information to the source device, the source device determines the form of image data that can be displayed by the first display device and the second display device based on the third specification information, the source device outputs image data based on the third specification information to the first display device, and the first display device outputs image data based on the third specification information to the second display device.

[0195] According to the image display system described in Appendix 7, image data of suitable specifications for the image display device and external display device used as the sink device is automatically selected and output from the source device. Therefore, user convenience is improved.

[0196] 3.8. Appendix 8

[0197] The image display system described in Appendix 8 is, in Appendix 7, wherein the first display device, when the first specification information and the second specification information are different from each other, selects the lower specification among the specifications contained in the first specification information and the specifications contained in the second specification information, thereby generating the third specification information.

[0198] According to the image display system described in Appendix 8, since the image data format is consistent with the lower-level specifications, both the image display device and the external display device can project / display images more reliably.

Claims

1. An image display device comprising: Projection device; Power supply device; A communication device having a first interface and a second interface; The first control circuit controls the power supply device; A second control circuit, which controls the projection device, and is different from the first control circuit; and The third control circuit controls the communication device and is different from both the first and second control circuits. The third control circuit performs the following processing: The connection status of the image output device that detects the output image data is with the first interface; Acquire the image data output by the image output device; and The image data is output from the second interface to an external display device.

2. The image display device according to claim 1, wherein, When the projection device is unable to project an image based on the image data, the first control circuit causes the power supply device to stop supplying power to the projection device, while the power supply device maintains power supply to the third control circuit and the communication device.

3. The image display device according to claim 1, wherein, The third control circuit performs the following processing: Detect the connection status between the external display device and the second interface; Obtain the specification information output by the external display device; and The obtained specification information is output to the image output device. The format of the image data is determined based on the specification information.

4. The image display device according to claim 1, wherein, The first control circuit, the second control circuit, and the third control circuit are each configured independently.

5. An image display system comprising: a source device; a first display device connected to the source device; and a second display device connected to the first display device. The second display device outputs second specification information related to the image display of the second display device to the first display device. The first display device outputs first specification information and second specification information related to the image display of the first display device to the source device. Based on the first specification information and the second specification information, the source device determines the format of the image data that can be displayed by the first display device and the second display device, and the source device outputs the determined image data to the first display device. The first display device outputs the image data to the second display device.

6. The image display system according to claim 5, wherein, When the first specification information and the second specification information are different from each other, the source device determines the format of the image data according to the lower specification among the specifications contained in the first specification information and the specifications contained in the second specification information.

7. An image display system comprising: a source device; a first display device connected to the source device; and a second display device connected to the first display device. The second display device outputs second specification information related to the image display of the second display device to the first display device. The first display device generates third specification information based on first specification information and second specification information related to image display on the first display device, and outputs the third specification information to the source device. Based on the third specification information, the source device determines the format of the image data that can be displayed by the first display device and the second display device, and the source device outputs the image data based on the third specification information to the first display device. The first display device outputs image data based on the third specification information to the second display device.

8. The image display system according to claim 7, wherein, When the first specification information and the second specification information are different from each other, the first display device selects the lower specification among the specifications contained in the first specification information and the specifications contained in the second specification information, thereby generating the third specification information.

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