JPH10214070A - Display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To always conduct normal communication by compensating for the failures of communication while plural number of devices are connected to each other. SOLUTION: A display device 3 is connected to a PC1 and a PC2 employing conventional video signal lines and also connected with duplex communication lines, respectively. If the video signals outputted by the PC1 are selected and displayed on the device 3, the display conditions of the device 3 such as various adjustments related to the display size, the display position and the contrast, for example, are controlled from the PC1 side through a C1. Moreover, specific information of the device 3 such as the control condition and identification information are transmitted to the PC1 side. In order to switch the input to the display 3 from the PC1 to the PC2, the display 3 newly makes a communication condition initializing request or a reset request against the PC2 so as to conduct communication.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a display device capable of displaying an image and reproducing sound based on a video signal or the like output from a computer device or the like.
In particular, it relates to a display device that communicates with a computer device or the like.

[0002]

2. Description of the Related Art In recent years, in the field of computers, particularly personal computers (hereinafter, referred to as PCs), a plug and play (PLUG & PLAY, hereinafter referred to as plug & play) function has been regarded as important. This is a function that enables the PC user to avoid troublesome setting work for various devices (including the display device) connected to the PC. Is also expensive. In the case of a display device, a PC
If you connect a display device to the video signal output terminal of
Alternatively, when the power of the connected PC and the display device is turned on, a standard display image state can be obtained without adjustment. An example of such a display device is described in JP-A-7-302068. Here, a communication line is provided between the display device and the PC, the PC reads identification information and timing information of the display device, and generates a video signal timing or a video signal format that can be displayed on the display device, and the PC generates a video signal. Output from the output terminal.

On the other hand, in order to provide ease of adjustment, P
In some cases, a communication line is provided between C and the display device to transmit a display control signal or control command from the PC to the display device. When the control signal or the control command is received by the display device, the content of the signal is determined and, for example, the display size and the display position are adjusted. By installing the communication line in this way, the software on the PC is operated, and the display adjustment of the display device can be easily performed by an operation from an input device such as a mouse or a keyboard connected to the PC. Such an example is disclosed in JP-A-7-168.
No. 547 is cited.

[0004]

In the above prior art, a computer and a display device connected to each other are one-to-one. However, in a conventional display system including a display device and a computer, since sufficient consideration was not given to communication between the display device and the computer, when the connected computer device changed on the display device side. If communication failure occurs, images are not displayed correctly, or if the display device's power save mode is enabled, the power to the display device will be cut off and the computer and other peripheral devices connected on the communication line will be disconnected. Communication could not be performed in some cases. Also, since the communication line and the video signal line exist independently, it may be difficult to control the display state of the display device, for example, the display size, position, brightness, display color, and the like via the communication line. Was. In addition, when various peripheral devices are connected to the communication line, if the computer serving as the control host is switched, there is a possibility that the control of the peripheral devices may not be performed as it is.

Further, the communication function is stopped in a state or a situation where the computer device is not functioning because the computer device is a host although the communication line exists, and the use of the display device and the peripheral device is prevented. Sometimes became impossible.

Therefore, an object of the present invention is to solve the above-mentioned problems of the prior art, and to provide a display device capable of simultaneously connecting a plurality of computers, one of a plurality of display devices connected to a computer, or a plurality of display devices. To provide one display device among a plurality of display devices connected to the computer. Further, the display device can perform communication with the computer without any trouble. It is an object of the present invention to provide a display device which does not hinder communication with a peripheral device of a computer. Another object of the present invention is to provide a display device that can communicate with other peripheral devices even when the display device is used alone, that is, without being connected to a computer.

[0007]

In order to solve the above problems, the present invention provides a display device which can be connected to a plurality of computers at one time. A communication means capable of displaying a video signal from one of the computers and switching communication with the computer, and initializing a communication state with the computer in response to the switching of the video signal. An operating display device. Further, the display device of the present invention may include first communication means for transmitting display information to a computer and second communication means for performing two-way communication with the computer. Further, the display device of the present invention may include control means for controlling the communication means.

Further, the display device of the present invention may have a hub means for distributing communication between the computer and a peripheral device existing outside the display device. Further, if the display device of the present invention includes a power supply for supplying power to the hub, the power supply can be controlled by the control.

Further, the display device according to the present invention may include a video demodulation means for reproducing an analog video signal from data (digital signal) relating to video display inputted via the communication means.

Alternatively, the display device of the present invention may include audio demodulation means for reproducing an analog audio signal from data (digital signal) related to audio display input via the communication means.

Here, the computer is not limited to a PC as long as it has a computer function including a computer device, and may be any device.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Specific embodiments of the above invention will be described below with reference to the drawings. FIG. 1 shows an embodiment of the present invention. Here, a configuration diagram in a case where, for example, two computer devices are connected to a display device is shown. Here, two computer devices are used.
The same is true even if one or more computer devices are connected. As described above, since a plurality of computers can be connected to the display device at a time, it is not necessary for the user to reconnect the computer that he or she wants to use each time.
In the figure, reference numerals 1 and 2 denote computer devices (hereinafter, referred to as PC1 and PC2), and reference numeral 3 denotes a display device according to the present invention. The display device 3 is P
C1 and PC2 and a normal video signal line, for example, a video graphic adapter (Video Graphic A)
video signal cables and connectors of bidirectional communication specifications (hereinafter referred to as C1 and C2).
Respectively). However, here, the video signal line and the communication line are shown separately for the sake of convenience, but the difference may affect the present invention regardless of whether they are actually separate lines or within one cable. There is no.

Another embodiment of the present invention will be described below. Now, as an initial state, the PC 1
Are selected and displayed, and the operation in the case where the communication through the communication line C1 is performed is as follows. First, before entering this state, the communication between the display device 3 and the PC 1 is initialized, and the initialization is performed immediately after the display device 3 and the PC 1 are started. That is, immediately after the display device 3 and the PC 1 are connected, or the connected display device 3
Immediately after power is supplied to PC1 and PC1. In the state where the video signal output from the PC 1 is selected and displayed on the display device 3, various adjustments regarding the display state of the display device 3, for example, the display size, the display position, or the display of the contrast, etc., can be made via the PC 1 via C 1.
It is possible to control from the side, and it is also possible to transmit the control state of the display device 3 and unique information such as identification information to the PC 1 side. In this case, the communication between the display device 3 and the PC 2 has not been initialized at this time, and thus the PC 2 and the display device 3 are not in a state where communication by the plug-and-play function is possible. Therefore, when the input of the display device 3 is switched from the PC1 to the PC2, the display device 3 makes a communication initialization request or a reset request to the PC2 along with the signal switching, so that the communication can be performed. less than,
The internal operation of the display device 3 in that case will be described in more detail.

FIG. 2 is an internal configuration diagram of the display device 3 in FIG. In FIG. 2, reference numeral 21 denotes a first PC
Connector C for receiving video signal from (PC1)
N1 and N22 are connectors CN2 for receiving a video signal from the second PC (PC2), and 23 are connectors CM1 and 24 for connecting communication lines for performing a second communication which is bidirectional communication with PC1. Connectors CM2 and 25 for connecting communication lines for performing a second communication which is bidirectional communication with the PC1
Switching circuits SW1 and 26 for switching between the video signal from PC1 and the video signal from PC2 are switching circuits SW2 and SW2 for switching the first communication with PC1 or PC2.
7 is a switching circuit SW3 for switching the second communication connected with the video signal cable line, 28 is a memory circuit for storing display ID information, 29 is a video circuit, 30 is a drive circuit, 31 is a control circuit, and 32 is a control circuit. A display device 33 for displaying images is an input means such as a switch for instructing a signal switching. Here, the driving circuit 3
0 indicates that the method changes depending on the display device 32. For example, if the display device 32 is a CRT (Cathode
ube), it functions as a so-called deflection circuit.

When the display device 3 shown in FIG. 2 is connected to the PC 1 as an initial state, the display device 3 stored in the memory circuit 28 for realizing the plug & play function of the PC 1 via the connector CN1. The display ID information that is the unique information is transmitted to the PC 1.
The PC 1 creates a video signal that can be displayed on the display device 3 from the received data and outputs it to the connector CN1. In this case, the communication for transmitting the display ID information, which is the unique information of the display device 3 stored in the memory circuit 28, to the PC 1 is the first communication.

If the first communication is successful, the connector C
The second communication between the display device 3 and the PC 1 is performed via M1. In the second communication, the display device 3 performs the reception of the screen adjustment command in the display device 3, the transmission of the internal information of the display device 3, and the like independently of the first communication. When the second communication is performed, the image display on the display device 3 is continuously and appropriately performed by the video signal and the synchronization signal created and transmitted by the PC 1.
Here, for example, the display device 3
When the user performs a switch operation to switch from the PC 1 in use to the PC 2, a switching instruction signal is input to the control circuit 31. The control circuit 31 determines that there is a PC switching request, and first, the connector CM of the second communication.
1 to the PC 1 via a switch preparation instruction signal. PC
In order to prepare for the switching, information 1 such as various current setting values and video signal timings for the display device 3 is held, and the PC 1 starts a resuming operation in preparation for being selected and connected to the display device 3 again. Then, P
A switch preparation completion report signal is transmitted from C1 to the display device 3 via the second communication connector CM1. In response to this, the control circuit 31 switches the switching circuit S
By controlling W1, SW2, and SW3, a communication line for performing video signal and other communication is switched to the PC2 side. At this time, the memory circuit 28 is set to the output ready state for the PC 2. Immediately after the switching of the switching circuit, an initialization request signal or a reset request signal for starting the first communication is transmitted from the control circuit 31 to the PC 2 via the second communication connector CM2. Then, the PC 2 is in an initial state immediately after the power is turned on, the display ID information stored in the memory circuit 28 is transmitted to the PC 2 side via the connector CN2 of the first communication, and the PC 2 transmits an image suitable for the display device 3. Output video signals in signal format. This operation is similar to the above-described operation when the video signal of PC1 is selected. Further, when switching from PC2 to PC1 again, the control circuit 31 performs the second switching in the same manner as described above.
And issues a switching preparation instruction signal to PC2 via the communication connector CM2. In preparation for switching, the PC 2 holds information such as current various setting values and video signal timings for the display device 3 by the resume function,
Is selected and connected to the display device 3. The control circuit 31 of the display device controls the internal switching circuits, and connects to the PC 1 again. Control circuit 3
1 outputs a reconnection request signal to PC1 via a communication line connected to the second communication connector CM1,
The PC 1 can return to the original state by resetting the state of the previous connection held by the resume function for the display device. Furthermore, PC1 returns to P
When switching to C2, the same operation as described above is performed and switching is performed.

Each operation associated with the above-mentioned switching is continued until the power of the display device or the PC is turned off, and the operation after the power is turned on is the same as the case described above. Furthermore, in the embodiment shown here, the number of computers connected to the display device 3 is two,
As described above, it is possible to cope with a case where there are more than two computers. In that case, the number of connectors of the display device, the number of inputs of various switching circuits, and the control circuit 3
The number of compatible computers corresponds to the maximum number of connectable computers. Further, FIG. 2 illustrates the case where the first communication and the second communication are independent, but it is of course possible to perform processing on the same communication line. In that case, the memory circuit 28 is connected to the control circuit 31, and the display I is connected via the control circuit 31 at the time of initial setting.
It sends out the D information to the communication line and performs bidirectional communication with the PC to exchange various data described above such as control information of the display device.

Next, FIG. 3 is a configuration diagram showing another embodiment of the display device of the present invention. As in the case of FIG. 1, the number of PCs connected to the display device 3 of FIG.
It may be more than one. In FIG. 3, reference numeral 4 denotes a mouse as an example of a peripheral device connected to the display device 3,
Reference numeral 34 denotes a hub circuit (HUB) for distributing the second communication with the PC, and the same reference numerals as those in FIG. 2 provide the same functions.

In FIG. 3, a hub circuit 34 for distributing the second communication with PC1 or PC2 to peripheral devices is added to the display device of FIG. Hub circuit 3
In addition to distributing communication with the PC 1 or PC 2, when information about the display device 3 is transmitted from the peripheral device to the hub circuit 34, the information transmission device 4 also sends the information to the control circuit 31. On the other hand, information output from the control circuit 31 to the PC is output to the PC via the hub circuit 34. When the switching operation of the PC connected to the display device is performed in FIG. 3, similarly to the case described with reference to FIG. 2, the switching preparation request is issued from the control circuit 31 to the currently selected and connected PC1 or PC2 before switching. Send a signal. Then, the PC1 or PC2 temporarily holds the setting conditions, information, and the like for all the peripheral devices on the communication line connected via the hub circuit 34, and prepares for switching.
The display device 3 recognizes that the switching preparation is ready, and switches each of the switching circuits 25 to 27. When the switching is completed, the control circuit 31 requests the newly selected and connected PC side to reset communication with various peripheral devices connected on the communication line via the hub circuit 34. The resetting work at the time of communication switching is performed as described above.

As another operation of FIG. 3, when a switching request signal is input from the input means 33, the control circuit 31
A switching request signal is transmitted via the hub circuit 34 and the switching circuit 26 to the selected PC that is performing the communication. In response to the request for the signal, the PC being selected sends a reset command signal to each peripheral device or hub circuit 34. Then, the display device 3 and the hub circuit 34
Peripheral devices, such as the mouse 4 etc., connected to the
Is reset or disconnected, and at the same time, the control circuit 31 controls the switching circuits 25 to 27 according to the reset command signal to perform the switching operation of the connected PC. Immediately after the switching, each peripheral device is re-recognized by the PC connected after the switching, and various communication initial settings are performed again.

As still another operation, in FIG. 3, when a switching request signal is input from the input means 33, the control circuit 31 sends a control signal to the hub circuit 34 in accordance with the request content of the signal, and The communication between each of the peripheral devices connected to the circuit 34 and the PC is forcibly disconnected. Thereafter, the control circuit 31 switches the switching circuits 25 to 27 inside the display device.
To switch the connection destination PC. After the completion of the switching, the control circuit 31 causes the hub circuit 34 to resume communication between each peripheral device and the PC. By its operation,
Switching only the PC while maintaining the connection state between the PC before switching and each peripheral device via the hub circuit, and communicating with each peripheral device via the hub circuit 34 with the newly selected PC. Becomes possible.

By the above operation, it is possible to reduce the trouble of switching the communication between the PC and the peripheral device including the display device, which occurs when the video signal output from the PC is switched to the video signal output from another PC. It becomes possible.

FIG. 4 is a diagram showing still another embodiment according to the present invention. In the figure, reference numeral 35 denotes a power supply circuit of the hub circuit 34, and other components having the same reference numerals as those in FIG. 3 have the same functions. The operation of FIG. 4 will be described below.

In the display device 3 shown in FIG.
4, communication is performed between the control circuit 31 and the selected PC. Normally, the power supply circuit 35 is used as a power supply for communication with the hub circuit 34 and peripheral devices.
Power supply to other peripheral devices connected to the device or to a communication control system of the peripheral device.
When the display device 3 shifts to the power save mode in accordance with an instruction from the selected PC, the control circuit 31
Controls the power supply circuit 35 to stop supplying power to peripheral devices connected to the hub circuit 34. Alternatively, the control circuit 31 controls the power supply circuit 35 to stop the power supply from the display device 3 to the hub circuit 34 and peripheral devices,
Instead, the hub circuit 34 is connected to the P circuit via the second communication line.
The hub circuit 34 and peripheral devices are controlled by the power supplied from C. The above operation will be described in more detail with reference to FIG.

FIG. 5 is a configuration diagram showing the internal configuration of the hub circuit 34 in FIG. In the figure, 51 is a hub control circuit,
52 is a power system switching circuit. In the figure, during normal operation, the power supply system switching circuit 5 is controlled by the hub control circuit 51.
2 supplies power from the power supply circuit 35 of FIG. 4 and supplies power to PC peripheral devices connected to the hub control circuit 51. Here, when the display device 3 enters the power save mode, an instruction to shift to the power save mode is transmitted from the control circuit 31 inside the display device to the hub control circuit 51 inside the hub circuit 34, and the hub control circuit 51 The switching circuit 52 is controlled to stop supplying power to peripheral devices connected to the hub circuit 34. further,
The hub control circuit 51 may control the power supply system switching circuit 52 to select a power supply line from an external power supply, specifically, a power supply line sent together with a communication signal line from the PC. By the above operation, the power supply from the display device 3 to the peripheral devices connected to the hub circuit 34 is stopped, and the power consumption of the display device itself can be reduced.

Further, in FIG. 5, even when the peripheral device connected to the hub control circuit 51 is in an unused state or a standby state even in a normal use state, the port of the peripheral device is determined, and The power supply switching circuit 52 can be controlled so that the communication power supply connected to the device is turned off. At this time, when a communication restart request or communication designation is performed from the PC to the peripheral device in the power saving state, the hub control circuit 51 detects the communication restart request signal or the communication designation signal, and the hub circuit in the power off state. 3
The corresponding port No. 4 is controlled to be in the power-on state, and the communication between the peripheral device and the PC is returned to a state where communication is possible. In the power control described above, even when the display device is in the power save state, the hub control circuit 51 controls the power supply from the PC to perform distribution to the operating peripheral devices,
With this control, it is possible to suppress power consumption due to communication on the PC side. By performing power control as needed as described above, it is possible to finely suppress power consumption during communication with a PC.

FIG. 6 is a diagram showing another embodiment according to the present invention. In the figure, reference numeral 61 denotes a computer device (hereinafter, PC)
, 62 to 64 are display devices having a function of communicating with a PC. In the figure, each of the display devices 62 to 64 has a video signal input terminal and a communication signal input / output terminal. The operation of the display devices 62 to 64 displays a video signal sent from a PC, and also displays the video signal via a communication line. This is a display device that performs bidirectional communication with a computer device and can be controlled by a PC so as to provide an optimum display state in accordance with the received video signal. Further, each of the display devices has a hub circuit similarly to the display device having the communication function described in each of the above embodiments of the present invention, and can distribute and branch a communication signal to another display device. It has the function to do. Therefore, the communication signal output from the PC 61 is input to the display device 1 62, is branched by the hub circuit inside the display device 1, is input to the display device 63 63, and is output by the hub circuit inside the display device 63. It is possible to input communication signals to sequentially connected display devices and distribute communication signals to the display device N of 64. On the other hand, the video signal is PC
61 to each display device. From the above, the number of display devices that can be connected to one PC depends on the supply capability of the PC that the PC can provide. As described above, since the communication lines for transmitting the video signals are connected to the respective display devices via different paths, the correspondence between the video signal transmitted from the PC and the display device receiving the video signal is established. is required. The association is performed according to the following procedure.

[0028]

[Table 1]

Table 1 is a table for explaining one method of setting the correspondence. As shown in the table, in order to be able to recognize which display device is the transmission destination of the video signal output by the PC, the PC determines the polarity of the horizontal and vertical synchronization signals output together with the video signal in each combination. The polarity is determined so that they do not match. Each display device transmits the polarity information of the input synchronization signal and the identification information of the peripheral device connected on the communication line via the communication line.
Send back to PC when communication with C is initialized. In this way, the PC can recognize the correspondence between the destination display device and the video signal to be sent to the display device. In this case, the number of display devices according to the embodiment of the present invention that can be connected to the PC is up to four depending on the combination of the positive and negative polarities of the horizontal and vertical synchronization signals.
Further, in the embodiment of the present invention, it is possible to associate a video signal with a display device by the presence or absence of a horizontal and vertical synchronization signal instead of the polarity information of the synchronization signal. Table 2 shows an example of the correspondence.

[0030]

[Table 2]

In this case, since the display device cannot display an image when all the synchronization signals are lost, the operation for confirming the correspondence is performed when the display device is first connected to the PC or when the power of the PC and the display device is turned on. It is performed immediately after. Also in Table 2, the number of display devices that can be connected to the PC is up to four depending on the combination of the presence or absence of the synchronization signal. Further, if the methods of Tables 1 and 2 are used in combination, and a method of a combination thereof is used, up to nine display devices can be identified by checking the polarity and presence / absence of the synchronization signal. It is possible to identify a correspondence relationship with a display device that should receive a video signal.

Further, the display device of FIG. 6 transmits display information such as its own characteristic information, a serial number, a serial number, and receivable video signal timing to a PC via a communication line existing in the same cable as the video signal line. And a communication line for performing a first communication that can be transmitted to the communication device. By comparing the display information sent from the first communication line with the display information sent via the second communication line, which is a two-way communication for adjusting the display device in FIG. 6, And the PC can recognize the correspondence between the display device connected to the video signal line and the display device to be controlled for display adjustment. In this case, the number of display devices that can be connected to the PC is not particularly limited. Further, the correspondence can be identified by a simple identification number instead of the display information.

FIG. 7 shows still another embodiment of the present invention. In the figure, reference numeral 71 denotes a video signal switching circuit;
2 is a drawing processing circuit, 73 is a video decoder circuit, 74 is a communication control circuit, 75 is an audio decoder circuit, 76 is an audio processing circuit, 77 is a speaker, and FIG. 1 shows the other embodiments of the invention. The same reference numerals as those in FIG. 6 have the same functions. The operation will be described below.

The communication control circuit 74 communicates with the PC via the hub circuit 34 via the connector 23 and outputs video signals from the PC to the display device, or communicates with other peripheral devices via the hub circuit 34. And the communication is P
When the video signal is transmitted to the display device C by communication via the connector 23 and the PC performs video processing and the like to output the video signal to the display device, the video signal switching circuit 71 connects the analog video signal input side from the connector 21 to the display device. Switching control is performed so that the user can make a selection. Further, the control circuit 31 controls the video circuit 29 and the drive circuit 30 according to the display control command of the display device sent from the communication control circuit 74. Next, a basic operation in a case where the display device is disconnected from the PC or a case where communication between the display device and the PC is not performed due to a state where the PC is turned off or the like is described. explain. In this case,
The display device controls communication and video processing performed by the PC by itself, and independently communicates with various peripheral devices connected to the communication line. In the embodiment of the present invention, the video device communicates with a drive device of a disk recording medium such as a CD-ROM drive or an imaging device such as a camera via the hub circuit 34 as the video device, and outputs video data output from a peripheral device. Can be processed and displayed in the display device. This operation will be described in detail below.

The communication control circuit 74 communicates with digital video equipment such as a CD-ROM and a digital camera via the hub circuit 34. Digital video data or other information output from a digital video device or the like
Is transmitted to the communication control circuit 74 via the communication control circuit 74. The communication control circuit 74 extracts a video data portion necessary for display and outputs the video data portion to the video decoder circuit 75. The video decoder circuit 73
When the transmitted video data is data compressed by a video compression technique such as the MPEG system, for example, a circuit for performing a so-called decoding process, which is a process of returning to a state of digitized video data before compression. It is. Next, the decoded video data is sent to the drawing processing circuit 72, reproduced into an analog video signal, and returned to a signal format that can be received by a normal display device. The output video signal of the drawing processing circuit 72 is input to the video circuit 29 and the drive circuit 30 via the switching circuit 71, and the video data transmitted from the peripheral device connected to the display device via a communication line is displayed on the display device of the display device. 32 on the video. As described above, according to the embodiment of the present invention, even when the host computer device is powered down or not connected, if a peripheral device is connected to the display device, necessary video information can be reproduced in the display device. It is possible to display on a display device by processing. Using this method, P
The display device can be used without C, and the use of the display device can be varied.

Similarly, an audio signal can be output by processing inside the display device even when the host computer is powered down or not connected to the display device. In the case of reproducing an audio signal, the communication control circuit 74 is connected via the hub circuit 34 shown in FIG.
Outputs the audio data portion to the audio decoder circuit 75. If the input audio data is digital audio data and the digital audio data is data compressed, the audio decoder circuit decompresses the data and outputs it to the audio processing circuit 76. The audio processing circuit 76 converts the audio signal into an analog audio signal, and outputs the analog audio signal from the speaker 77 as normal audio. As described above, the audio can be reproduced by the audio reproduction processing of the display device itself without the processing of the host PC.

FIG. 8 shows another embodiment of the present invention.
In the figure, reference numeral 81 denotes a power supply circuit, and other reference numerals which are the same as those in FIGS. 1 to 7 have the same functions. In FIG. 8, the audio decoder circuit 75 and the audio processing circuit 7
6 and a speaker 77, the operation of which is the same as that of FIG. 7, but the power supply circuit 81 of FIG. 8 has a function of performing power control on the audio reproduction processing portion.
A power supply circuit exists independently of a power supply circuit that controls power supply to circuits other than the audio reproduction processing portion inside the display device. The power supply circuit 81 is controlled by the communication control circuit 74. If audio data to be output is not input to the communication control circuit 74 by communication via the hub circuit 34, power is supplied to the power supply circuit 81 by control of the communication control circuit 74. Is stopped, and the audio reproduction processing portion is shifted to the power save mode. The control for the power supply circuit 81 can be performed either independently or in conjunction with the power save mode of the display device itself, and the selection of those methods is displayed on an adjustment switch or display device 32 provided in the display device. It can be selected from the adjustment menu or the like by operating the adjustment switch or button. Although the embodiment of the present invention has been described with respect to the audio reproducing portion, the video decoder circuit 73 and the drawing processing circuit 72
Similarly, the present invention can also be applied to a video playback processing portion having a power supply control independent of a power supply circuit that controls power supply to circuits other than the video playback processing portion of the display device. As described above, fine power control is performed by providing a power supply circuit for controlling power supply to each of the portions of the display device that perform audio reproduction processing and video reproduction processing, thereby reducing the power consumption of the display device itself. It is possible to operate so as to suppress as much as possible.

FIG. 9 is a system configuration diagram showing still another invention. In the figure, reference numerals 91, 92 and 93 denote display devices according to the present invention, and the same reference numerals as those in FIG. 6 have the same functions. The operation of FIG. 9 will be described below.

In FIG. 9, reference numeral 61 has the same function as the PC shown in FIG. 6, and performs the same operation. On the other hand, the display devices 91, 92, and 93 are display devices that can be connected to a plurality of PCs 61 and have a function of selectively displaying video signals output from the connected PCs. For this function, the display device 3 shown in FIG.
This function enables the output video signal from the PC to be selectively displayed on the display device. Here, the display device 91 is connected to a plurality of PCs 61 via a bidirectional communication line, and performs bidirectional communication with a selected PC. In the bidirectional communication, the display device 91 is displayed according to an instruction from the selected computer. It controls the internal circuit of the device and transmits the internal information of the display device to the computer. Further, a plurality of bidirectional communications, which are communications between a plurality of PCs and the display device 91, are also distributed to other display devices 92, 93 and the like. This function is the same as distributing two-way communication from a PC as shown in FIG. 6 to the display devices 62, 63, and 64. Control is performed. By the above communication control, each of the display devices 91, 9
Communication between the PCs 2 and 93 and the plurality of PCs is controlled, and each of the display devices 91, 92 and 93 can display an image based on the video signal from the selected PC on its own display device. Also, the identification of each display device is determined by the state of the synchronization signal sent from the PC side as in FIG. 6, and each display device can be realized by holding the identification number given from the PC side. When the PC selected by the display device is switched, the retained identification number is notified to the switched PC via the bidirectional communication line. The notified PC can continue to recognize the connected display device,
The inconvenience such as wiring connection due to switching of the PC to be selected can be eliminated.

In FIG. 9, the two-way communication lines of a plurality of PCs and the display device are intensively connected to one of the display devices 91. However, in the present invention, these two-way communication lines are connected to a plurality of the plurality of display devices. The same function can be realized even when the display device is connected to the display device in a distributed manner.

[0041]

As described above, according to the present invention, in a current system in which a computer device and a display device communicate with each other, a communication defect when a plurality of devices are connected to each other is compensated for and always compensated. Normal communication can be performed. In addition, when another computer peripheral device is connected to the communication, the power supply to be supplied by the display device can be controlled as needed, so that power consumption is suppressed.
Requires minimal power. Further, instead of the communication data processing by the computer device, communication data from another peripheral device connected on the communication line can be processed and displayed on the display device itself, so that a stand-alone usage method can be provided.

[Brief description of the drawings]

FIG. 1 is a system configuration diagram showing a first embodiment of the present invention.

FIG. 2 is a configuration diagram of a first display device according to the first embodiment.

FIG. 3 is a configuration diagram of a second display device according to the first embodiment.

FIG. 4 is a configuration diagram of a third display device according to the first embodiment.

FIG. 5 is a configuration diagram of a hub circuit in the third display device.

FIG. 6 is a system configuration diagram showing a second embodiment of the present invention.

FIG. 7 is a configuration diagram of a display device according to a third embodiment of the present invention.

FIG. 8 is a configuration diagram of a display device showing a fourth embodiment of the present invention.

FIG. 9 is a system configuration diagram showing a sixth embodiment of the present invention.

Continued on the front page (72) Inventor Kozo Masuda 292 Yoshida-cho, Totsuka-ku, Yokohama-shi, Kanagawa Prefecture Inside the Multimedia Systems Development Division of Hitachi, Ltd. (72) Inventor Kazufumi Kikuchi 292 Yoshida-cho, Totsuka-ku, Yokohama-shi, Kanagawa Hitachi, Ltd. Visual Information Media Division

Claims (17)

[Claims] 1. A display device connectable to a plurality of computers and capable of displaying a screen based on video signals from the connected computers. 2. A display device connected to a computer and another display device, the display device being capable of displaying a screen based on a video signal from the computer, and transmitting information communicated with the computer to the other display device. A display device comprising means for delivering to a display device. 3. A display device connected to a plurality of computers and capable of selectively displaying a screen based on a video signal from the connected computer, wherein the computer transmits the selected video signal. A communication unit that transmits the individual information of the display device at the time of starting up the computer or at the time of a request from the computer, from a computer that transmits the selected video signal,
When the display is switched to a video signal from a computer other than the computer, the communication is performed by requesting the computer newly selected by the communication unit to be in a state after the startup of the selected computer. Or a communication initialization request to the selected computer to resume communication. 4. The display device according to claim 3, wherein a first communication of the communication means capable of transmitting at least individual information of the display device from the display device to the computer is switched. A first switching unit, a communication between the display device and the computer for transmitting an instruction of a display state of the display device, a communication for transmitting and receiving individual information of the display device, or a communication of control information of the display device. Second switching means for switching a second communication among the communication means for performing a certain bidirectional communication; instruction means for instructing switching of an input video signal; and each of the switching means based on an output of the instruction means And the selected computer communicates with the selected computer via the second switching means. Control means for controlling the second communication with the display device, wherein the control means can control the communication means. 5. A display device connected to a plurality of computers and capable of selectively displaying an image based on a video signal from the connected computer, wherein the display device transmits the image to the computer from the display device. First switching means for switching a first communication capable of transmitting at least individual information; communication between the computer and the display device for instructing a display state of the display device; individual information of the display device Second switching means for switching a second communication, which is a two-way communication for communicating communication of the display device or communication of control information of the display device; an instructing means for instructing switching of an input video signal; Controlling the switching means based on the output of the instruction means; Control means for controlling said second communication between said selected computer and said display device via a stage. 6. The display device according to claim 4, wherein said control means has been selected via said second communication before controlling said first and second switching means. A display device, comprising: transmitting a switching preparation request signal to a computer; and transmitting a communication initialization request signal to the newly selected computer via the second communication after the switching control. 7. A display device connected to a plurality of computers and capable of selectively displaying an image based on a video signal output from the connected computer, wherein the display device sends the display to the computer side. First to output at least device individual information
First switching means for switching the communication between the computer and the display device, and second switching for switching the second communication between the computer and the display device, or between the computer and the peripheral device of the display device. Means, and information of a second communication which is two-way communication between the computer selected by the second switching means and the display device, or two-way communication between the selected computer and a peripheral device of the display device. Hub means for distributing to the internal circuit of the display device and the peripheral device, and when switching the video signal from the selected computer to the display device to a video signal from another computer, Instructing means for instructing input switching, and based on the output of the instructing means The second communication via the hub means between the computer and the display device selected via the second switching means and between the selected computer and the peripheral device, controlling each of the switching means. Control means for controlling the display device. 8. A display device according to claim 7, wherein said control means controls said first and second switching means and controls said first and second switching means via said hub means. Performing a second communication, transmitting a switching preparation request signal to the already selected computer by the second communication, and performing the second communication with a newly selected computer after the switching control; 2. A display device for transmitting a communication initialization request signal to the newly selected computer by the communication of 2. 9. The display device according to claim 7, wherein said control means controls said first and second switching means and controls said second switching means via said hub means and said already selected computer. Communication of the second
Transmitting a communication reset request signal to the peripheral device to the already selected computer by the communication of the above, and performing the second communication with the newly selected computer via the hub means after the switching control. Characteristic display device. 10. A display device connected to at least one computer and capable of displaying an image based on a video signal output from one of the connected computers, wherein the display device displays A first transmitting at least individual information of the display device to a computer side;
And a second means for performing a second communication that is a two-way communication between the computer and the display device or a two-way communication between the computer and a peripheral device of the display device.
Communication means; hub means for distributing information of two-way communication by the second communication means to the internal circuit of the display device and the peripheral device; power supply means for supplying power to the hub means; Control means for controlling bidirectional communication with the display device or a circuit inside the display device, wherein the control means controls the power supply means according to a communication state of the second communication. A display device characterized by the above-mentioned. 11. The display device according to claim 10, wherein said control means controls said power supply means when bidirectional communication between said peripheral device connected to said hub means and said computer is stopped. The display device according to claim 1, further comprising: a control for stopping power supply to the device, or a control for stopping power supply to a portion where the peripheral device is not connected to the hub means. 12. A display device connected to a computer and capable of displaying an image based on a video signal output from the computer, comprising: a two-way communication between the computer and the display device; or a computer and the display device. Communication means for performing two-way communication with the peripheral device; hub means for distributing the information of the two-way communication by the communication means to the peripheral device of the display device and another display device by two-way communication; and controlling the communication. And control means for controlling a circuit inside the display device. The control means detects information having a vertical and horizontal synchronization signal input together with the video signal, and detects the vertical information via the bidirectional communication. Or a display for transmitting information of a horizontal synchronization signal to the computer. Ray device. 13. The display device according to claim 12, wherein the information on the vertical and horizontal synchronization signals is information on the polarities of the vertical and horizontal synchronization signals, and the information on the vertical and horizontal synchronization signals in the initial stage of communication between the display device and the computer. A display device, comprising: information on the presence or absence of a horizontal synchronization signal, or information on a combination of information on the polarities of the vertical and horizontal synchronization signals and information on the presence or absence of the vertical and horizontal synchronization signals. 14. A display device connected to a plurality of computers and capable of selectively displaying an image based on a video signal from the connected computer, wherein a bidirectional communication between the selected computer and the display device is provided. Hub means for distributing information to a peripheral device of the display device or another display device, and controlling the bidirectional communication between the selected computer and the display device, or controlling the peripheral device and the peripheral device via the hub circuit. Control means for performing communication control for distributing the information by the two-way communication to the another display device, or controlling the internal circuit of the display device based on control information sent from the selected computer. A display device characterized by the above-mentioned. 15. A display device connected to a plurality of computers and capable of selectively displaying an image based on a video signal output from the computers, wherein the selected one of the plurality of computers and the display Communication means for performing bidirectional communication with the device, hub means for distributing information by bidirectional communication to a circuit inside the display device, another display device, or a peripheral device; and the computer via the hub means Control means for controlling bidirectional communication with the display device and controlling a circuit inside the display device, and when the selected video signal is newly selected as a video signal output from another computer The bidirectional communication through the communication means or the hub means under the control of the control means. A display device for transmitting individual information of the display device, another display device connected to the hub means, or a peripheral device to the newly selected computer side. 16. A display device connected to a computer and capable of displaying an image based on a video signal output from the computer, communication means for communicating with the computer, and distributing the communication to peripheral devices of the display device. Hub means; video demodulation means for reproducing video data or video information transmitted from a peripheral device via the hub means into an analog video signal; output of the video demodulation means; Video switching means for switching between video signals, and control means for controlling each of the above means, the control means, when the display device and the computer are not connected, or the display device and the computer When the communication is not being performed, the switching unit is controlled to control the video decoding. Display apparatus characterized by an image based on an output from the means is a video can be displayed. 17. A display device connected to a computer and capable of displaying an image based on a video signal output from the computer, communication means for communicating with the computer, and distributing the communication to peripheral devices of the display device. Hub means; audio demodulation means for reproducing an analog audio signal from audio data or audio information transmitted by communication from a peripheral device via the hub means; and control means for controlling each of the above means. The controller controls the audio demodulator to take in audio data or information when there is no communication between the display device and the computer or when no communication is performed, and reproduces an audio signal. A display device, comprising: