JP2002341438A - Projection type image display device and image display system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide projection type image display device and system capable of displaying the same image as a projected and displayed image also on an external display device arranged on another place, and when a plurality of images are inputted, capable of easily projecting and displaying a required image. SOLUTION: The projection type image display device is provided with image input parts 100A to 100C capable of inputting a plurality of image information in parallel, projection display means 106, 108 for selectively projecting and displaying the plurality of image information supplied through the image input parts 100A to 100C, an image output part 114A for outputting the image information supplied through the image input parts 100A to 100C and displaying the image information on an external display device 201 such as a monitor device, and a control means 115 capable of setting up a 1st mode for outputting the image information displayed by the projection display means out of the plurality of image information from the image output part and a 2nd mode for outputting image information optionally selected from the plurality of image information from the image output part.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a projection type image display device called a projector or the like and an image display system using the same.

[0002]

2. Description of the Related Art Conventionally, there is no projector device which projects an image supplied from a video or a personal computer on a screen by enlarging and displaying the image on the screen as an electric video signal. Therefore, for example, when a participant is located away from the place where the conference is being held, even if the projector device is used at the place where the conference is being held, the participant can hear the sound by the video conference system or the like. However, there is an inconvenience that the image displayed by the projector device on the conference side (only seen by the conferee) cannot be directly viewed, and the content of the conference cannot be sufficiently understood only by the sound.

Further, recent projector devices are provided with a plurality of input terminals, and a plurality of image supply devices such as a video and a personal computer are connected to these input terminals at the same time. Image information to be displayed (that is, an image supply device) can be selected.

[0004]

However, it is often the case that only the presenter does not know which image supply device is connected to which input terminal of the projector device. In this case, when an image to be projected and displayed is to be switched, it is not known whether or not the image has been switched to a correct image until the projected and displayed image is confirmed, and the presentation must be interrupted during that time. For this reason, there is a possibility that the smooth progress of the conference may be hindered.

Therefore, the present invention can display the same image as the image being projected and displayed on an external display device installed at another place. It is an object of the present invention to provide a projection-type image display device and an image display system capable of easily projecting and displaying an image.

[0006]

In order to achieve the above object, according to a first aspect of the present invention, an image input unit capable of inputting a plurality of pieces of image information in parallel and a plurality of image information supplied through the image input unit are provided. A projection display unit for selectively projecting and displaying image information, an image output unit for outputting a plurality of image information supplied through an image input unit and displaying the image information on a monitor device or other external display device, and A first mode for outputting image information for which image display is being performed by the projection display means from the image output unit, and a second mode for outputting image information arbitrarily selected from the plurality of image information from the image output unit. The projection type image display device includes a control unit that can set a mode.

In the second invention, an image input unit capable of inputting a plurality of image information in parallel, a projection display means for selectively projecting and displaying a plurality of image information supplied through the image input unit, An image output unit that outputs a plurality of pieces of image information supplied through the image input unit and displays the plurality of pieces of image information on a monitor device or another external display device; and a projection display unit among the plurality of pieces of image information from a first output terminal of the image output unit. The projection-type image display device includes control means for outputting image information projected and displayed and outputting image information arbitrarily selected from a plurality of pieces of image information from a second output terminal of the image output unit.

According to these inventions, the same image information as that projected and displayed is displayed on the external display device by setting the first mode or through the first output terminal, or by setting the second mode or Through the second output terminal, it is possible to display arbitrarily selected image information (the same image information as the image information being projected and displayed or image information not being projected and displayed) on the external display device.

Therefore, for example, when an external display device is installed via a communication device at a location (participant side) away from the installation location (conference participant side) of the projection-type image display device, the first mode is set. Alternatively, through the first output terminal, the same image as the image projected and displayed by the projection-type image display device can be shown to the participant on the external display device.

Further, by displaying a plurality of pieces of image information sequentially on an external display device or collectively in a multi-screen configuration by setting a second mode or through a second output terminal, the presenter or the like can be displayed. The presentation assistant can easily check a plurality of images, and can easily and accurately select an image to be projected and displayed.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS (First Embodiment) FIG. 1 shows the configuration of a projector (projection image display) according to a first embodiment of the present invention.

Reference numeral 100A denotes a first external signal input terminal. In this embodiment, a VGA signal output from a presenter's personal computer (PC) is input. 10
Reference numeral 0B denotes a second external signal input terminal. In this embodiment, a VGA signal from a document camera (visualizer) is input. 100C is a third external signal input terminal. In this embodiment, an output signal of a VTR (video signal reproducing device) is input. As described above, in the projector device of the present embodiment, image signals (image information) from a plurality of image supply devices can be input in parallel.

A scan converter 100 converts a signal input to the input terminal 100A into a signal having a predetermined number of pixels corresponding to the number of elements of a liquid crystal panel (LCD) 106 described later. Similarly, 101 is an input terminal 100
A scan converter 102 converts the signal input to B into a signal having a predetermined number of pixels, and 102 converts the signal input to the input signal 100C.

The first to third external signal input terminals 10
0A, 100B, 100C and scan converter 1
The image input unit referred to in the claims is constituted by 00 to 12.

Reference numeral 103 denotes scan converters 100 to 10
A switch circuit for selecting and outputting one signal from the signals processed in step 2, and 104 including a character or the like as a signal from the switch circuit 103 in accordance with a control signal from a controller (control means) 115 described later. A multiplexing circuit (OSD) for multiplexing.

Reference numeral 105 denotes a liquid crystal drive circuit for driving a liquid crystal panel 106, which will be described later, based on an output signal of the multiplexing circuit 104; 106, a liquid crystal panel driven by the liquid crystal drive circuit 105; 107, a projection light source; Reference numeral denotes a screen on which an image displayed on the liquid crystal 106 is enlarged and projected by the projection lens 108.

The liquid crystal drive circuit 105, the liquid crystal panel 106, the projection light source 107, and the projection lens 108 constitute a projection display means as defined in the claims.

Reference numeral 109 denotes a first memory circuit to which an output signal of the scan converter 100 is input, 110 denotes a second memory circuit to which an output signal of the scan converter 101 is input, and 111 denotes an output signal of the scan converter 102. A third memory circuit.

Reference numeral 119 denotes a memory controller which controls writing and reading to and from the memories 109 to 111 based on a control signal from the controller 115 described later. Reference numeral 112 denotes a switch circuit that selects or combines signals from the first to third memory circuits 109 to 111 according to a control signal from a controller 115 described later and outputs the selected signals.

Reference numeral 120 denotes a scan converter circuit which converts the number of pixels of the output signal from the SW 112 into a signal format which can be displayed on a monitor (external display device) 201 which will be described later. Reference numeral 113 denotes an output signal from the image processing circuit 112 which is described later. A multiplexing circuit (OSD) that multiplexes a signal such as a character according to a control signal from the control circuit 115 that performs the operation. A drive circuit 114 outputs a signal from the multiplexing circuit 113 to the outside, and an output terminal 114A outputs a signal from the drive circuit 114 to the outside. Scan converter circuit 12
0, the multiplexing circuit 113, the drive circuit 114, and the output terminal 114A constitute an image output unit referred to in the claims.

Reference numeral 115 denotes a controller for controlling each block of the projector apparatus, and 116 denotes input terminals 100a to 100a.
The liquid crystal 106 is selected from the signals (images) input to 102a.
An image selection switch 117 for selecting an image to be transmitted to the liquid crystal 106 and selecting an image to be projected and displayed is the same signal as the signal to be transmitted to the liquid crystal 106 (first mode: referred to as an interlock mode here). A monitor output changeover switch for selecting whether the signal is an arbitrary signal including a signal to be transmitted to the liquid crystal 106 (second mode: here, referred to as an independent mode). Mouse (position information input means) for input, 201 is a monitor (external display device), 201a is an input terminal of the monitor 201, 121 is whether or not an operation menu (operation index) is displayed on the monitor 201 in an on-screen display mode OSD SW for selecting whether or not.

FIG. 2 shows an image input to each input terminal and a projection display on a screen 200 (hereinafter also referred to as an optical output).
5 shows an example of an image and a monitor display image in each of the above modes. Specifically, FIG. 2A shows an input image to input terminal 100A, FIG. 2B shows an input image to input terminal 100B,
(C) shows an input image to the input terminal 100C.

(D1), (D2), and (D3) are input terminals 100A, 100B, 100
The screen projection image when C is selected, the monitor display image when the linked mode is set, and the monitor display image when the independent mode is set are shown.

Although this figure shows a case where all the monitor display images when the independent mode is set are selected as images different from the screen projection image, the same monitor display image as the screen projection image can be selected. is there.
Further, (E) shows that when the independent mode is set, the OSD SW
Shows a case where the operation menu is displayed on the monitor display image by turning on.

FIG. 3 shows each monitor display mode in the independent mode. FIG. 3D shows a case where the image from the input terminal 100A is selected as the monitor display image when the independent mode is set.

Further, (1) and (3) in FIG.
FIG. 3 (2) shows a case where images from the input terminals 100C and 100A are selected as monitor display images when the independent mode is set. The figure shows a case where the operation menu is displayed on the monitor, and (1) to (3) show a case where the operation menu is displayed so as to be superimposed on each monitor display image.

Next, based on the flowchart of FIG.
The operation of the projector device shown in FIG. 1 will be described. First, a power supply (not shown) is turned on (step 2).
01), the controller 115 initializes each unit based on the initial settings described in Table 1 (step 2).
02).

[0028]

[Table 1]

That is, the input terminal 103A of the SW 103
And the output signal 103O are selectively connected, and the character multiplexing OFF is set in the multiplexing circuit 104. Further, the input terminal 112A and the output terminal 112O of the SW 112 are selectively connected, and the multiplexing circuit 113 is set to the character multiplexing OFF. In this embodiment, the SWs 116 and 117 are set as tact SWs, and the detection at the time of initialization is not performed. Further, it also detects whether the mouse 118 is connected. Furthermore, monitor output switching SW
117 is set to the interlock mode.

When the initialization is completed, the scan converter 100 converts the monitor output signal of the PC connected to the input terminal 100A into the number of pixels of the liquid crystal panel 106, for example, 1024 pixels × 768 pixels, for each frame. Is done. In addition, the number of frames is not limited to the number of frames of the input signal and can be output. However, since this is a general signal processing of the scan converter, the detailed description is omitted here.

Similarly, the scan converter 101 converts the number of pixels of the document camera input to the input terminal 100B into 1024 × 768 pixels, and the scan converter 102 converts the signal of the VTR device input to the input terminal 100C. The output signal is also converted to 1024 pixels × 768 pixels and sent to the next stage.

The SW 103 is connected to each scan converter 10
0 to 102 are selected and output. Since the output signal of the scan converter 100 has been selected by initialization, the signal from the PC is
4, the light is displayed on the liquid crystal panel 106 by the liquid crystal panel driver 105, and the light transmitted through the liquid crystal panel 106 is projected and displayed on the screen 200 by the projection lens 108 by the irradiation of the light source 107.

At the same time, each scan converter 10
Output signals of 0 to 102 are stored in memories 109 to 11 respectively.
Entered into 1 and saved. In the initial state, no special processing is performed by the memory controller 119, and the same signals as the output signals from the scan converters 100 to 102 are output from the memories 109 to 111, respectively.

The SW 112 at the next stage is 112 in the initial state.
Since A is selected and the signal from the memory 109 is selected, from the output terminal 112O of the SW 112,
The same signal as the output signal from the output terminal 103O of the SW 103 is output.

The next stage of the scan converter 120 is a switch
112 from a video signal (for example, NTSC system)
And outputs the signal to the multiplexing circuit 113 in the initial state without any multiplexing in the initial state. The driver circuit 114 outputs the signal sent from the multiplexing circuit 120 from the output terminal 114A as it is. The output terminal 114A is connected to the monitor 2
01 is connected to the input terminal 201A of the monitor 201 by the projector device.
The same image as the image displayed at 0 is displayed. However, the screen projection image and the monitor display image are images of the same source, but have different resolutions, frame rates, and the like.

<Description of Interlocking Mode / Pointing Using Mouse> When the selection switch 116 is pressed from this initial state and the input signal is switched to the signal from the input terminal 100B (image signal from the document camera) (step 203 → 2).
04 → 208 → 209), in the initial state, the monitor output switch SW117 is in the state where the interlock mode is set (steps 209 → 210).
A signal from the input terminal 100B is input to both W112, and an image from the document camera connected to the input signal terminal 100B is displayed on the screen 200 and the monitor 201.

When the selection switch 116 is depressed and the input signal is switched to the signal from the input terminal 100C (image signal from the VTR) (steps 203 → 204 → 208 →
212), in the initial state, the monitor output switch SW117
Since the interlock mode is set (step 212 → 213), a signal from the input terminal 100C is input to both the SW 103 and SW 112, and the input signal terminal 1 is input to both the screen 200 and the monitor 201.
The image from the VTR connected to 00C is displayed.

When the selection switch 116 is pressed to switch the input signal to the signal from the input terminal 100A (image signal from the PC) (steps 203 → 204 → 20).
5) In the initial state, the monitor output switching SW 117 is in the state in which the interlock mode is set (steps 205 → 206), so that the signals from the input terminal 100A are input to both SW 103 and SW 112, and the screen 2
00 and the monitor 201 both have the input signal terminal 100
The image from the PC connected to A is displayed.

For this reason, since the same image as the image displayed on the screen 200 is always automatically displayed on the monitor 201, the trouble of switching the monitor input signal every time the screen display image is switched can be omitted.

Therefore, in a conference or presentation, the presenter can make a presentation smoothly while viewing the monitor display image that is the same as the screen display image at hand.

When the OSD SW 121 is depressed (step 231), the controller 115 outputs the character code signal of the cursor to the multiplexing circuits 104 and 113 because the current display mode is the interlocking mode.
Using the multiplexing circuits 104 and 113, the pointer moved by the mouse 118 is multiplexed on the screen (step 2).
41 → 242 → 243).

Thus, the screen 200 and the monitor 2
01 on both display screens (although the display resolution is different, it is difficult to multiplex to the same position strictly, but it is possible to display at the same position without discomfort)
And the presenter can use it to indicate the position of interest on the display image.

<Explanation of Operation Menu Display / Character Multiplexing / Independent Mode> Next, the operation when the display mode is set to the independent mode by operating the monitor output switch SW 117 will be described.

When the independent mode is selected by the monitor output switch SW 117 (steps 221 → 222 → 224 → 23)
4), the controller 115 turns off the pointer multiplexing display multiplexed by the multiplexing circuit 104,
13, the pointer display and the operation menu display are multiplexed.

That is, when a signal to press the SW 121 is input to the controller 115 from the previous state, the controller 115 outputs a pointer display signal and a character code signal of an operation menu shown in Table 2 to the multiplexing circuit 113.

[0046]

[Table 2]

The multiplexing circuit 113 converts the character code sent from the controller 115 into character information,
The signal is multiplexed with the video signal input from the scan converter 120 and output to the driver circuit 114. As a result, signals are sent to the driver circuit 114, the output terminal 114A, the monitor input terminal 201A, and the monitor 201, and an operation menu is displayed on the monitor 201.

For example, when the pointer is moved with the mouse 118 on "optical output" in the main menu shown in the uppermost row of Table 2 and the mouse is clicked, an optical output setting menu shown in the second row is displayed.

Then, for example, move the pointer to the "input terminal B".
When the mouse is clicked and the mouse is clicked, the controller 115 determines that the input terminal B has been selected.
The signal selected by W112 is switched to the signal from the memory 110 (steps 241, 242, 243, and 251).
→ 252 → 253 → 254). As a result, only the monitor display image is switched to the image input to the input terminal 103B, while the screen display image remains the image input to the input terminal 103A.

<Explanation of Multi-Image Display> In the display mode menu shown in Table 2, when “multi-image” is selected, each input signal input to the input terminals 100A, 101A, and 102A is temporarily stored. The output signals from the memories 109, 110, and 111 are subjected to filtering to reduce the number of pixels in the vertical and horizontal directions to half each of the normal output of the image signal stored in each memory to reduce the number of pixels. To a quarter. Then, the image data of the first line of the original image is selected from the memory 109 (half of one line of the output image), and
, The image data of the first line of the original image is selected.

Subsequently, after one horizontal blanking period, the image data of the second line is selected from the memory 109, and the image data of the second line in the memory 110 is selected. Similarly, the selection of the image data is continued, and the memory 109, the memory 110
When the output of the image data is completed, the readout is similarly performed from the memory 111.

However, in this case, since there is no data corresponding to the right image, a blanking level signal is output without selecting image data. This reading is performed at the same clock rate as usual.

By this memory read operation, the multi-image output of the image data stored in the memories 109, 110 and 111 is performed to the output terminal 114A. At the same time, the controller 115 character-multiplexes input terminal names corresponding to the respective input signals at predetermined positions. Therefore, by looking at this image, it is possible to grasp what image is being input to which input terminal without switching the input signal, so that the screen display image can be smoothly switched.

Therefore, when making a presentation or the like using the projector device of the present embodiment, the projector device is set to the independent mode, and the screen attendant is shown to the conference participants, while the presenter or the assistant presenter is presented. The presentation is made while viewing the display image on the monitor 201 such as a video monitor or a small liquid crystal display device. And the presenters,
Even if the monitor display image can be different from the screen display image or a multi-screen image, the contents of multiple input images can be checked and the necessary screen image can be immediately and mistaken when necessary. Since the display can be performed without any change, the presentation can be smoothly performed.

In this embodiment, the case where the display mode and the screen display image are switched by clicking on the operation menu using the mouse has been described.
A touch operation panel may be provided on the screen of the monitor 201 so that the display mode, the screen display image, and the like can be switched based on the position information pressed on the touch operation panel.

(Second Embodiment) FIG. 5 shows the configuration of a video conference system (image display system) according to a second embodiment of the present invention using the projector device described in the first embodiment. ing. In FIG. 5, the left side is the presenter's hall, and the right side is the participant's hall to listen to the presentation, and the sound and images from the participant's hall are sent to the presenter's hall.

Reference numeral 301 denotes a video conference device installed at the presenter's venue, which can communicate with the video conference device 401 installed at the participant's venue via the communication line 451.

Reference numeral 302 denotes a venue imaging camera for photographing a presenter or a presenter's venue. Reference numeral 303 denotes a PC 305 for outputting conference materials and the like to the projector device 303, a VTR 306 for reproducing an image signal recorded on a VTR tape, and a VTR 306. This is a projector device of the present embodiment that displays an output image signal from the video conference device 301.

Further, reference numeral 304 denotes a projector device 303.
Is a screen on which the output image is projected. Reference numeral 307 denotes a microphone that picks up the sound of the presenter's hall and the sound of the presenter. Reference numeral 308 denotes a speaker that outputs an audio signal output from the video conference system 301.

Reference numeral 402 denotes a participant-side video conference system 4
01 is a camera for photographing the venue connected to 01. Reference numeral 403 denotes a projector device (external display device) that enlarges and projects an image signal output from the video conference system 401 onto a screen 404.

Reference numeral 405 denotes a microphone that picks up the audio of the participant's venue, and 406 denotes a speaker that outputs an audio signal output from the video conference device 401.

The video conference devices 301 and 401 stand up stand-alone, select and take in either the image signal from the camera 302 for photographing the venue or the image from the projector device 303, and receive the audio signal from the microphone 307. Take in, compress each and multiplex them to make communication line 4.
51.

The transmitted signal is transmitted to the video conference device 401.
And the video conference device 401 separates the multiplexed compressed audio data and the multiplexed image data and decompresses them. The image data is output to the projector device (external display device) on the participant's side, and the audio signal is output to the speaker 406.

Accordingly, at the participant's venue, the image selected by the photographing camera 302 at the presenter's venue or the output image from the projector 303 is viewed as the projection image by the projector 403. Can be.

For this reason, the person present at the participant's venue is the state of the presenter's venue, the presenter, and the projector device 30.
3 makes it possible to see an image equivalent to the image output.

When the projector device 303 is set to the interlock mode, the image output from the projector device 303 to the projector device 403 on the participant side is a screen projection image as the presentation on the presenter side proceeds. Is automatically switched in accordance with the switching, so that the participant can always see an image equivalent to the image output on the screen 304 at the presenter's venue.

In this embodiment, a dedicated output terminal (first output terminal) for causing the projector device 303 to project and display the same image as the screen projection image by the projector device 303 on the projector device 403 on the participant side.
Output terminal) and monitor 319 is connected to output terminal 1 in FIG.
If the mouse 318 is connected to the projector device 303 by connecting to the output terminal (second output terminal) corresponding to 14A, the same image is projected on the screen by both projector devices 303, and the meeting person's side is displayed. Even if a presenter or a presentation assistant sets the projector device 303 to the independent mode and operates the mouse 318 while viewing another image or a multi-image through the monitor 319, the conference can proceed smoothly. Good.

In this case as well, the identification display of the image displayed on the monitor 319, the operation menu display, and the pointer display are changed to the second display.
May be made to be performed by the monitor 319 through the output terminal.

[0069]

As described above, according to the first and second aspects of the present invention, the first mode is set or the first mode is set.
The same image information as the image information being projected and displayed is displayed on the external display device through the output terminal of the external display device, or the image information arbitrarily selected by the setting of the second mode or through the second output terminal is displayed on the external display device. Can be displayed.

Therefore, for example, when an external display device is installed via a communication device at a location (participant side) away from the installation location (conference participant side) of the projection type image display device, the first
By setting the mode or through the first output terminal, the same image as the image projected and displayed by the projection type image display device can be shown to the participant on the external display device. In addition, a presenter or a presentation assistant can display a plurality of pieces of image information sequentially on an external display device at hand or collectively in a multi-screen configuration by setting a second mode or through a second output terminal. And a plurality of pieces of image information can be easily confirmed. Therefore, the presentation can be smoothly performed while easily and accurately selecting an image to be projected and displayed.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating a configuration of a projector device according to a first embodiment of the invention.

FIG. 2 is an explanatory diagram showing an input image, a screen projection image, and a monitor display image in the projector device.

FIG. 3 is an explanatory diagram showing a monitor display example in an independent mode in the projector device.

FIG. 4 is an operation flowchart of the projector device.

FIG. 5 is a conceptual diagram of a video conference system according to a second embodiment of the present invention.

[Explanation of symbols]

 100A-100C Input terminal 100-102 Scan converter 104,113 Multiplex circuit 109-111 Memory 115 Control circuit 116 Input selection switch 117 Monitor output changeover switch 200,304,404 Screen 201,319 Monitor 301,401 Video conference device 302,402 Camera 303,403 Projector device

Claims (11)

[Claims] An image input unit capable of inputting a plurality of pieces of image information in parallel; a projection display unit for selectively projecting and displaying a plurality of pieces of image information supplied through the image input unit; An image output unit for outputting the plurality of pieces of image information thus displayed on a monitor device or other external display device; and outputting the image information of the plurality of pieces of image information projected and displayed by the projection display unit to the image output unit. Control means for setting a first mode for outputting from a plurality of pieces of image information and a second mode for outputting image information arbitrarily selected from the plurality of pieces of image information from the image output unit. Type image display device. 2. The projection type image display device according to claim 1, wherein the control unit displays the plurality of image information on the external display device in a multi-screen configuration in the second mode. . 3. The external device according to claim 2, wherein the control unit causes the external display device to display an identification of the image information output from the image output unit in the second mode. 3. The projection type image display device according to 1 or 2. 4. The display means of the external display device, wherein the control means displays on the display screen of the external display device a selection operation of image information to be projected and displayed by the projection display means, a selection operation of the mode, and other indications of a user operation. The projection type image display device according to any one of claims 1 to 3, wherein 5. A control device, comprising: a mouse and other position input devices for inputting information indicating a position on a display image, wherein said control means is displayed by said projection display means in said first mode. A pointer is displayed at a position on the image corresponding to the position information input from the position input device, and in the second mode, the pointer is input from the position information input device on a display screen by the external display device. 5. The projection type image display device according to claim 4, wherein a pointer for performing the user operation is displayed at a position corresponding to the position information. 6. An image input unit capable of inputting a plurality of pieces of image information in parallel, projection display means for selectively projecting and displaying a plurality of pieces of image information supplied through the image input unit, and supplying the plurality of pieces of image information through the image input unit. An image output unit for outputting the plurality of pieces of image information thus displayed on a monitor device or another external display device, and projecting the plurality of pieces of image information from the first output terminal of the image output unit by the projection display unit Control means for outputting the displayed image information and outputting, from a second output terminal of the image output section, image information arbitrarily selected from the plurality of pieces of image information. Display device. 7. The projection according to claim 6, wherein the control means outputs the plurality of pieces of image information from the second output terminal so as to be displayed on the external display device in a multi-screen configuration. Type image display device. 8. The control means outputs, from the second output terminal, information for causing an identification display of image information output from the second output terminal to be performed on a display screen of the external display device. The projection-type image display device according to claim 6, wherein the image is output. 9. The control unit displays, from the second output terminal, a selection operation of image information for causing the projection display unit to perform image display, a selection operation of the mode, and a display serving as an index of a user operation. 9. The projection type image display device according to claim 6, wherein information to be output on a display screen of the external display device is output. 10. A touch operation panel is provided on the monitor device, and the control means responds to the operation by operating the touch operation panel on an image displayed on the monitor device in a multi-screen configuration. 10. The projection type image display device according to claim 1, wherein an image to be displayed is displayed by the projection display means. 11. A communication device for communicably connecting the projection type image display device according to claim 1 to an image output unit of the projection type image display device and a monitor device or another external display device. An image display system comprising: