Abstract:
A display monitor includes a plurality of monitor inputs, a monitor switch for switching between the plurality of monitor inputs, a plurality of universal serial bus (USB) ports, where a first one of the USB ports is positioned at a first location and is dedicated to a first processing device, a second one of the USB ports is positioned at a second location and is dedicated to a second processing device, and a third one of the USB ports is positioned at a third location and is dedicated to either the first processing device or the second processing device. In addition, the display monitor includes a USB switch for switching between the plurality of USB ports to selectively activate the plurality of USB ports, where the monitor switch is internally linked to the USB switch to cause the monitor switch and the USB switch to switch concurrently with each other.

Description:
BACKGROUND 
       [0001]    Computer monitors or displays are typically large and expensive compared to other computer peripherals. Hence, in many instances (in business or home applications) computer monitors are shared between multiple computers, such as personal computers (PCs) or workstations, to save cost and desk space. This is especially true for the larger and more expensive monitors. For example, an office user may share a single display monitor between a desktop computer and laptop computer, or multiple office users may share multiple display monitors with multiple computers. Similarly, a home user or a college student in a dorm may share one monitor between a PC and a video component, such as a cable-box or a DVD player, whereby the display monitor may be used as both a television monitor and a computer display. Hence, as referred herein, a “display monitor” (or “monitor” for short) is any device that is operable to display video or images output from a computer or any other video component. 
         [0002]    Conventionally, the dual use of or dual connection to a single monitor is made possible through the use of multiple inputs that are available on some monitors or the use of an external switching device, such as a KVM (Keyboard, Video, Mouse) switch. As is generally understood in the art, a KVM switch is a device that allows a console to be shared between multiple PCs. As the name KVM implies, the console includes a keyboard, a video display and a mouse. Certain KVM products also support sharing of analog audio signals and generic USB devices. A typical setup of a desktop KVM system  100  is illustrated in  FIG. 1 . As shown, a KVM switch  130  allows a monitor  110 , a keyboard  140  and a mouse  150  to be connected to either a first PC  120  or a second PC  122 . Switching between the PCs  120  and  122  is typically achieved through a user selection of a button on the KVM switch  130  or through application of a specific key-press combination on the keyboard  140 . 
         [0003]    While the first PC  120  or the second PC  122  is not connected to the keyboard  140  and mouse  150 , the KVM switch  130  simulates the presence of such input devices so that these computers do not generate errors or notifications regarding the lack of a keyboard and a mouse. Traditional KVM devices support analog VGA displays, PS/2 keyboards and PS/2 mice. In recent years, keyboards and mice have migrated to USB (Universal Serial Bus) connections, with displays migrating to DVI (Digital Visual Interface) or HDMI (High-Definition Multimedia Interface) connections. The KVM industry has responded to these changes and now offers KVM products that also support DVI, HDMI and USB connections. 
         [0004]    In lieu of a KVM switch, a monitor with multiple inputs (multi-input monitor) may be used. Lower-end, older consumer monitors tend to be limited to one VGA (Video Graphics Array) and one DVI-D (DVI-Digital) connection for video inputs. However, many newly manufactured monitors include at least two display signal input channels to allow, for example, two PCs to share a single monitor. A typical setup of using monitor switching is illustrated by the system  200  in  FIG. 2 . As shown, only the monitor  210  is shared between a first PC  220  and a second PC  222 , with the keyboards  230 ,  250  and the mice  240 ,  260  being duplicated to provide each of the PCs  220  and  222  with one keyboard  230 ,  250  and one mouse  240 ,  260 . An advantage of using a monitor with multiple inputs is that it is a very cost effective solution and does not degrade video quality. For example, a typical 30-inch business monitor has three DVI-I inputs, a desirable feature for high-end monitor users. However, the convenience of a KVM switch is lost because the keyboard and mouse are not managed and need to be externally and independently switched. 
         [0005]    Alternatively, as illustrated by the system  300  in  FIG. 3 , it is possible to share a keyboard  340  and a mouse  350  by again adding a separate KVM switch  330 . In this scenario, the monitor switching and KVM switching are independent and need to be synchronized by the user. This is often confusing, however, because the monitor  310  and the KVM switch  330  may not use the same input (e.g., one may use a toggle, the other may use direct buttons or key-presses), and they may not show their switching states the same way. In addition, the video selection or switching feature within the KVM switch  330  is not connected, and thus, the video selection or switching feature circuit adds to the cost and the power consumption of the KVM switch  330  without an added benefit. 
         [0006]    Similar problems exist with conventional KVM solutions for sharing multiple monitors. The most commonly used multi-monitor KVM solutions are derived by users mixing independent features of a KVM switch with the integrated input selection features of their multi-input monitors. That is, monitors are each individually switched using their integrated source selection feature/button. In addition, a separate KVM switch is typically used to switch input devices, such as a keyboard and a mouse, for use with two or more computers that provide information display to the multiple monitors. 
         [0007]      FIGS. 4A and 4B , respectively, illustrate systems  400  and  450  having a typical implementation for multi-monitor switching as noted above. The systems  400  and  450  include two monitors, Monitor 1  ( 410 ) and Monitor 2  ( 412 ), that are connected to multiple computers, namely, PC 1  ( 420 ) and PC 2  ( 422 ). The systems  400  and  450  also each includes a KVM switch  430  and input devices, such as a keyboard  440  and a mouse  450 . Performing dual display switching between two host PCs ( 410  and  412 ) in the systems  400  and  450  requires multiple independent device selections. First, the user must manually switch an input selection on each monitor and also must switch the keyboard  440  and mouse  450  using the external KVM switch  430  (via a switch selection on the KVM switch  430  or a dedicated key press sequence programmed for the keyboard  440 ). In such a situation, it is easy for the various input/output/display devices to be out of sync with each other, and consequently presents an inconsistent and potentially confusing UI to the user. In addition, the video selection or switching feature within the KVM switch  430  is not connected, and thus, the video selection or switching feature circuit adds to the cost and the power consumption of the KVM switch  430  without an added benefit. Moreover, there exists a small number of external KVM products that support multiple monitors (as opposed to widely-available KVM products that support single-monitor sharing), but these are rare and expensive devices that often have image quality issues. 
         [0008]    Consequently, the conventional monitor-sharing solutions discussed above are typically unsatisfactory because KVM products are notorious for being expensive, finicky, and for degrading image quality. Further, a multi-input monitor does not manage the keyboard and mouse switching for user interface (UI) or user input. This often results in multiple keyboards and mice, or independent switching of the monitor and/or KVM-linked input devices (keyboard, mouse, etc.). 
         [0009]    Accordingly, it would be desirable to provide a monitor sharing solution for single and/or multi-monitor setups that is simple, user-friendly, and satisfactory to users. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0010]    Embodiments are illustrated by way of example and not limited in the following figure(s), in which like numerals indicate like elements, in which: 
           [0011]      FIG. 1  illustrates a typical desktop KVM (Keyboard, Video, Mouse) system; 
           [0012]      FIG. 2  illustrates typical video switching provided by a multi-input monitor; 
           [0013]      FIG. 3  illustrates a typical monitor-sharing setup that includes video switching at the multi-input monitor as well as device switching at an external KVM switch; 
           [0014]      FIGS. 4A and 4B , respectively, illustrate typical implementations for a multi-monitor switching that uses an external KVM switch; 
           [0015]      FIG. 5  illustrates a monitor-sharing system in which the KVM functionality is integrated within a monitor, in accordance with an embodiment of the invention; 
           [0016]      FIG. 6  illustrates a diagram of the internal logic of a KVM-monitor, in accordance with an embodiment of the invention; 
           [0017]      FIG. 7A  illustrates a KVM-monitor system for sharing multiple monitors across multiple PCs, in accordance with an embodiment of the invention; 
           [0018]      FIG. 7B  illustrates a diagram of an inter-monitor communication channel for a dual-display operation, for instance, the KVM-monitor system depicted in  FIG. 7A , in accordance with an embodiment of the invention; 
           [0019]      FIG. 7C  illustrates a KVM-monitor system for sharing multiple monitors across multiple PCs, in accordance with another embodiment of the invention; 
           [0020]      FIG. 7D  illustrates a diagram of an inter-monitor communication channel for a dual-display operation, for instance, the KVM-monitor system depicted in  FIG. 7C , in accordance with another embodiment of the invention; 
           [0021]      FIG. 8A  illustrates a KVM-monitor system for sharing multiple monitors across multiple PCs, in accordance with another embodiment of the invention; 
           [0022]      FIG. 8B  illustrates a diagram of an inter-monitor communication channel for a dual-display operation, for instance, the KVM-monitor system depicted in  FIG. 8A , in accordance with another embodiment of the invention; 
           [0023]      FIG. 9  illustrates a diagram in which a dedicated wired link is added between monitors for inter-monitor communication, in accordance with an embodiment of the invention; 
           [0024]      FIGS. 10A and 10B , respectively, illustrate various configurations of multiple monitors connected to each other for sharing, in accordance with an embodiment of the invention; 
           [0025]      FIG. 11  illustrates a diagram of a multi-monitor arrangement that uses proximity wireless communication for inter-monitor communication and monitor sharing, in accordance with an embodiment of the invention; and 
           [0026]      FIG. 12  illustrates a diagram of a multi-monitor arrangement in which each monitor is equipped with Bluetooth™ capability for wireless communication with each other, in accordance with an embodiment of the invention. 
       
    
    
     DETAILED DESCRIPTION 
       [0027]    For simplicity and illustrative purposes, the principles of the embodiments are described by referring mainly to examples thereof. In the following description, numerous specific details are set forth in order to provide a thorough understanding of the embodiments. It will be apparent however, to one of ordinary skill in the art, that the embodiments may be practiced without limitation to these specific details. In other instances, well known methods and structures have not been described in detail so as not to unnecessarily obscure the embodiments. 
         [0028]    With reference first to  FIG. 5 , there is shown a monitor-sharing system  500  in which the functionality of a KVM is integrated within a monitor, in accordance with one embodiment. The system  500  depicted in  FIG. 5  avoids complications typically found in conventional monitor-sharing solutions, such as the use of multiple input devices for multiple computers and the required independent switching of KVM-linked input devices that causes such devices to be out-of-sync. According to this embodiment, the integration of KVM functionality within the monitor  510  results in a “KVM-monitor” that offers the convenience of a true KVM while avoiding the need for independent switching of an external KVM switch. 
         [0029]    As shown in the system  500  in  FIG. 5 , there is provided a single monitor  510  for sharing between two computers, namely, PC 1  ( 520 ) and PC 2  ( 522 ), which are connected to the monitor  510  without going through an external KVM switch. Input devices, such as a keyboard  530  and a mouse  540  are also provided. Unlike the conventional arrangements shown in  FIGS. 1-4B , the input devices  530  and  540  are connected directly to the monitor  510  without going through an external KVM switch or the computers PC 1  and PC 2 . 
         [0030]    In addition, and as noted above, the monitor  510  is a “KVM-monitor” that is based on many newly-manufactured monitors, which already contain the functionality to switch between multiple monitor inputs (such as, HDMI, DVI-I, DVI-D, and/or DVI-A, etc.). They also typically contain a USB hub, with a single input port and multiple output ports. Therefore, the KVM-monitor  510  may be one of such monitors, modified to include an additional USB input port to provide a connection to the second computer PC 2   522 . The KVM-monitor  510  may also include a pair of additional dedicated USB output ports, such as 2 USB inputs for the keyboard  530  and the mouse  540 ). The KVM-monitor  510  also has the ability to appropriately switch USB port signals (to accommodate switching between the computers PC 1  and PC 2 ). Additionally, the monitor input switching and USB switching functions may be internally linked so that both switch together. Furthermore, USB switching may be optional so as to allow users that do not desire or require the KVM functionality to use the USB connectors as a standard USB hub (as with current existing monitors), and only the monitor inputs, such as, DVI, HDMI, etc., may be switched. 
         [0031]    Accordingly, the number of shared-connections to the monitor  510  depends on the number of available monitor inputs and on the provisioning of a matching number of USB input ports, together with at least a pair of dedicated or switching USB output ports (or, generally, interfaces for input devices) that the monitor enclosure are physically able to accommodate. 
         [0032]    For the KVM-monitor setup described above, various user-customizable USB port options and advanced configurations are possible. Existing monitors, with integrated USB hubs, associate all USB ports on the monitor to a single host PC. In the KVM-monitor case, port assignments may be matched to device routing, for example, by assigning all USB ports to the user&#39;s currently selected PC. However, the KVM-monitor  510  may afford users with greater flexibility and control over the individual USB port assignments. 
         [0033]    For example, device switching may always re-route certain devices, such as input devices like the keyboard and mouse. However, a user may wish that other specific devices remain connected to one PC (for example, external storage drive(s) that are attached to one or more USB ports of the monitor), independent from the device switching. In one embodiment, USB port control features within the monitor&#39;s on-screen control panel may be provided to achieve this level of control. This level of control provides the user with the option to independently configure each output (or downstream) USB port&#39;s behavior, allowing these individual USB ports to be switched with the device or to be assigned to a specific upstream USB port (as a standard USB hub). 
         [0034]    In another embodiment, the functionality of the USB ports on the monitor  510  may be locked based on the physical location or position of the USB ports on the monitor  510  or on behavior grouping. For example, the monitor  510  may have multiple USB ports  552  and  554  located on the left side, USB ports  560  and  562  located on the right side, USB ports  570  and  572  located on the bottom, and USB ports  574  located on the top of the monitor  510 . In this example, all of the USB ports  552  and  554  located on the left side of the monitor  510  are dedicated to one PC or device, and all of the USB ports  560  and  562  located on the right side of the monitor are dedicated to a second PC or device. In addition, the remaining USB ports  570 ,  572 , and  574  along the bottom and the top of the monitor  510  may be associated with either a first PC  520  or a second PC  522 . Thus, in this example, the spatial locations of the USB ports determine their operations without implementing port configuration features in the monitor&#39;s on-screen control panel. In addition, the monitor  510  may include labels (for instance, as shown in  FIG. 6 ) for the USB ports  552 - 556 ,  560 ,  562 , and  570 - 574  that enable the functionalities of the USB ports  552 - 556 ,  560 ,  562 , and  570 - 574  to be easily distinguished from each other. The labels may include text, for instance, “From Computer A” and “From Computer B”. In addition, or alternatively, the labels may include other distinguishing characteristics, such as, different colors, shapes, etc. 
         [0035]    According to a further example, some of the USB ports  552 ,  560 ,  570 , and  574  may be configured to become powered when either of the PCs  520  and  522  are active. In addition, other ones of the USB ports  562 ,  564 , and  572  may be configured to remain powered regardless of which of the PCs  520  and  522  is active. Still others of the USB ports  556  may be configured to remain active regardless of which of the PCs  520  and  522  is active and these USB ports  556  are not associated with either of the PCs  520  and  522 . 
         [0036]      FIG. 6  illustrates a diagram  600  of the internal logic of a KVM-monitor, such as the monitor  510 , to show how various components are linked, in accordance with one embodiment. As shown, the monitor includes 2 DVI ports  610  and  620 , 8 USB ports  630 - 644 , a DVI switch  650 , and a USB switch  660 . It should however be understood that the monitor may include any suitable number of DVI ports, USB ports, DVI switches, and USB switches without departing from a scope of the invention. 
         [0037]    The DVI switch  650  and the USB switch  660  are internally linked so that both switch together, as initiated by a user via, for example, a dedicated button pressed on the monitor itself or the monitor&#39;s on-screen control panel. Alternatively or additionally, the monitor  510  may be set up or programmed such that the user may initiate the switch by performing a predetermined key-press sequence, e.g., hot key(s), or through a trigger device switching (e.g., once an input device such as a keyboard or mouse is connected to a USB port, the monitor  510  detects such a connection and automatically switches so as to enable a corresponding A or B configuration to which the USB port belongs). 
         [0038]    Based on the user selection through any of the aforementioned modes, the monitor may be switched to the A or B configuration, to switch the display information from computer A (e.g., PC 1   520  in  FIG. 5 ) or computer B (e.g., PC 2   522  in  FIG. 5 ) to the monitor&#39;s screen. As a result, the connection from either DVI  610  or  620  becomes active and is displayed by the monitor  510 . In addition, each computer also connects to a single USB input port, namely PC 1   520  connects to USB port  630  and PC 2   522  connects to USB port  636 . User selection to the A or B configuration, in parallel with the display switching, results in one of the two USB input ports  630  and  636  connecting to the shared output USB port pair  624  and  644 . With the switch in the A position, input (upstream) USB port  630  connects to output (downstream) USB ports  642  and  644 . Likewise, with the switch in the A position, input (upstream) USB port  630  connects to output (downstream) USB ports  632  and  634 . Hence this pair of switching output or downstream USB ports is suitable for input of other devices (e.g., keyboard, mouse, etc.) that the user wishes to share between the two host computers, in sync with the display switching. 
         [0039]    In the case where the user wishes to circumvent the port switching process, peripherals that connect to output (downstream) USB ports  632 ,  634 ,  638  and  640  do not switch with the A or B configuration selection. As shown in  FIG. 6 , the output USB port pair  632  and  634  are internally wired to USB input port  630  (e.g., PC 1   520  from  FIG. 5 ), whereas the output USB port pair  638  and  640  are internally wired to USB input port  636  (e.g., PC 2   522  from  FIG. 5 ). 
         [0040]    Existing monitors with integrated USB hubs typically include automatic power control of the USB hub. That is, the USB hub is typically powered down (switched off) to be in sync with the monitor. Although this may save a little power, this may be an undesirable feature in many instances, for example if the host PC is performing a data back-up operation to an attached USB drive when the monitor decides to sleep. Hence, in one embodiment, the KVM-monitor  510  provides the user with an option to override the automatic power control of the USB hub so as to leave one or more USB ports permanently powered, for example, to charge a wireless phone or personal digital assistant (PDA). 
         [0041]    In many multi-monitor arrangements, especially for workstation configurations, users may connect their machines to multiple displays in order to increase the overall display area. One common configuration is to have a single computer, such as a PC (equipped with a multi-display graphics card), rendering an extended desktop display across multiple monitors. Hence, the aforementioned embodiments for sharing a single monitor may be extended for sharing multiple monitors across multiple devices, such as PCs. While various embodiments as described herein make reference to a system having two monitors and two PCs, it should be understood that such embodiments are scalable to accommodate more monitors and/or PCs (or other devices). 
         [0042]      FIG. 7A  illustrates a KVM-monitor system  800  for sharing multiple monitors across multiple PCs, in accordance with another embodiment. As shown therein, the first monitor  510  and the second monitor  812  are KVM-monitors. In addition, the keyboard  530  and the mouse  540  are depicted as being connected to the second monitor  812 . At least one of the USB ports of first monitor  510  and at least one of the USB ports of the second monitor  812  are arranged in a hierarchical tree architecture, in which the at least one of the USB ports on the first monitor  510  and the at least one of the USB ports on the second monitor  812  comprise leaf nodes of the hierarchical tree architecture, and in which the leaf node of the at least one USB port on the first display monitor is at a higher level than the at least one USB port on the second display monitor. A host node of the hierarchical tree architecture may be contained in both of the PCs  520  and  522 . In addition, the keyboard  530  and the mouse  540  are depicted as being connected to the leaf node USB ports of the second monitor  812 . The arrangement depicted in  FIG. 7A  enables an input switch in both of the monitors  510  and  812  to be triggered through, for instance, a key stroke or button activation, on an input device. In one regard, the hierarchical tree architecture of the USB ports enables a signal from the input device, such as, the keyboard  530  and the mouse  540 , to be propagated through each of the monitors  510  and  812  prior to going to the host, such that the monitors  510  and  812  are synched together, for instance, as also shown in  FIG. 7B . 
         [0043]    From a user&#39;s perspective, this KVM-monitor arrangement provides the convenience of a complete KVM switchover that is to occur across all of the monitors upon a single user action, such as at the press of monitor button or keyboard key-press sequence. That is, both the KVM-Monitor 1   510  and the KVM-Monitor 2   812  synchronize their switching so that when the user switches the input on one KVM-monitor, the other KVM-monitor switches accordingly. This is accomplished through creation of a communication channel between the KVM-monitors  510  and  812 , as facilitated by the USB connection  550  that uses existing USB ports on the monitors  510  and  812 . This communication channel facilitated by the USB connection  550  may be used by the KVM-monitors  510  and  812  to inform each other of their state changes and to monitor state changes of other KVM-monitors. It also enables functions and parameters to be coordinated across multiple monitors. For example, the monitors may be synchronized with respect to their on/off switching so that the user only needs to press one on/off button to switch all of the monitors on or off. Also, the monitors may be synchronized with respect to their brightness, contrast, color, temperature, language or other device specific configuration settings. The aforementioned inter-monitor communication channel may be scalable to any number of monitors and independent of devices such as PCs that are connected thereto. 
         [0044]      FIG. 7B  illustrates a diagram  820  of an inter-monitor communication channel for a dual-display operation, such as the one shown in  FIG. 7A , wherein integrated-KVM switching is performed based on key-press sequences or events (via the keyboard). Each of the KVM-Monitor 1  ( 510 ) and KVM-Monitor 2  ( 812 ) includes a KVM-Hub ( 822  and  830 ) to provide the integrated KVM functionality as described above, a DVI switch ( 824  and  832 ) to provide the multi-input functionality, and a display such as a liquid crystal display (LCD) ( 826  and  834 ) for displaying information. For simplicity purposes, connections between the PC 1  and PC 2  to both DVI switches  824  and  832  are not illustrated in  FIG. 7B . For such a dual display operation, the two integrated KVM-hubs  822  and  830  may be chained together to create a communications path between the two monitors  510  and  812 . As illustrated, both PC 1  ( 520 ) and PC 2  ( 522 ) are connected to the first monitor, KVM-Monitor 1  ( 510 ), and the keyboard  530  and mouse  540  are connected to the second monitor, KVM-Monitor 2  ( 812 ). This enables the USB hub hierarchy to be maintained and the key-press sequence commands to pass from the (downstream) keyboard  530  through both (upstream) KVM-monitors to the selected host PC via its respective USB master port ( 840  or  842 ). 
         [0045]    The USB connection  550 , such as a USB cable link, between the two KVM-monitors  510  and  812  forms a master-slave hub relationship. Normal keyboard and mouse usage is routed back to the selected PC (PC 1  or PC 2 ) via the two integrated USB Hubs  822  and  830 . Both KVM-monitors  510  and  812  have specific USB keyboard and mouse ports and have the ability to act as a keyboard and mouse proxy. For example, at power up (or turn on), KVM-Monitor 1  ( 510 ) may send a special command or identification while initializing its keyboard port. This initialization may be ignored by standard keyboards but recognizable by KVM-Monitor 2  ( 812 ), and it is used to disable the USB switching in KVM-Monitor 2 . Thus, KVM-Monitor 2  is slaved to KVM-Monitor 1  with respect to the switching of PC 1  and PC 2  for use with the keyboard  530  and mouse  540 . Then, upon recognizing a key-press command sequence from the keyboard  530 , KVM-Monitor 2  switches its display input channel (via its DVI switch  832 ) and also forwards the key-press command to the upstream KVM-Monitor 1 . In turn, KVM-Monitor 1  interprets the key-press sequence and also switches its display input channel (via its DVI switch  824 ), switches its USB KVM to select an alternate one of PC 1  and PC 2  as the new host. 
         [0046]    The keyboard proxy of KVM-Monitor 1  is configured to block the actual key-press command sequence from being passed to the selected host PC. To avoid incorrect switching, the downstream KVM-Monitor 2  may append the current (new) display input channel to the key-press command sequence that is sent to the upstream KVM-Monitor 1  to ensure a correct switching of the monitor. Alternatively, the command sequence may include a command to switch the monitor for viewing. 
         [0047]      FIG. 7C  illustrates a KVM-monitor system  850  for sharing multiple monitors across multiple PCs, in accordance with another embodiment. The KVM-monitor system  850  depicted in  FIG. 7C  is similar to the KVM-monitor system  800  depicted in  FIG. 7A . As such, only those features that differ from the KVM-monitor system  700  will be described with respect to the KVM-monitor system  850 . 
         [0048]    Initially, instead of connecting only to the KVM-hub  822 , the USB masters  840  and  842  of the PCs  520  and  522  are connected to both of the monitors  510  and  812  and are thus configured to interface with any attached peripheral or input device. In addition, the monitors  510  and  812  do not connect through to each other, but instead, rely on the host(s)  840  and  842  to determine the relationships between the monitors  510  and  812  and the input devices  530  and  540 . 
         [0049]    As all KVM-monitors have an internal controller, software drivers may be installed in the host PC(s) to issue commands to perform the appropriate KVM switching. Thus, when a PC performs an enumeration of the USB bus, it may detect how many KVM-monitors are connected to the host computer and may configure each appropriately (switch only the display or both the display and USB). The PC is aware of all the monitors (and controllers thereof) connected to the USB tree and therefore may receive state messages from any connected monitor, and may trigger switching on all of the monitors. 
         [0050]      FIG. 7D  illustrates a diagram  870  of an inter-monitor communication channel for a dual-display operation, such as the one shown in  FIG. 7C , wherein integrated-KVM switching is performed based on key-press sequences or events (via the keyboard). The diagram  870  of  FIG. 7D  includes all of the features of the diagram  820  depicted in  FIG. 7B . As illustrated, both PC 1  ( 520 ) and PC 2  ( 522 ) are connected to both the first monitor, KVM-Monitor 1  ( 510 ) and the second monitor, KVM-monitor 2  ( 812 ), and the keyboard  530  and mouse  540  are connected to the second monitor, KVM-Monitor 2  ( 812 ). This configuration also enables the USB hub hierarchy to be maintained and the key-press sequence commands to pass from the (downstream) keyboard  530  through both (upstream) KVM-monitors to the selected host PC via its respective USB master port ( 840  or  842 ). 
         [0051]      FIG. 8A  illustrates a KVM-monitor system  1000  for sharing multiple monitors across multiple PCs, in accordance with another embodiment. The KVM-monitor system  1000  depicted in  FIG. 8A  is similar to the KVM-monitor system  800  depicted in  FIG. 7A . As such, only those features that differ from the KVM-monitor system  800  will be described with respect to the KVM-monitor system  1000 . 
         [0052]    As shown in  FIG. 8A , the input devices  530  and  540  are depicted as being connected to the first monitor  510 . Assuming that the USB ports in the PCs  520  and  522  and the monitors  510  and  812  are in the hierarchical connection tree arrangement as discussed above, the first monitor  510  is at a higher level than the second monitor  812 . Thus, signals received from the input devices  530  and  540  may not be relayed to the second monitor  812  under the connection arrangements depicted in  FIGS. 7A-7D . To overcome this situation, each of the monitors  510  and  812  is equipped with an embedded USB (slave) microcontroller for display and connection switching, as shown in  FIG. 8B . 
         [0053]    As is generally known with USB connections, the USB protocol does not let devices communicate directly with each other and thus, the devices are intended to be pure slaves to a PC. In order to overcome this restriction, according to an example, one or both of the KVM-monitors  510  and  812  is equipped with USB master support to enable direct communication of information between the KVM-monitors  510  and  812  without having to go through one of the PCs  520 ,  522 . In another example, the USB protocol may be modified to enable such communications. In a further example, the KVM-monitors  510  and  812  may be equipped with specialized USB chips to enable the direct communication between the KVM-monitors  510  and  812 . 
         [0054]      FIG. 8B , more particularly, illustrates a component diagram  1050  detailing components in each KVM-Monitor  510  and  812  used in a setup of an inter-monitor communication channel for a multi-display operation, such as the one shown in  FIG. 8A , wherein integrated-KVM switching is performed based on the user selecting an input source, via either a button or the on-screen control panel, on any connected monitor instead of a key-press sequence or event. For this setup, each of the connected monitors, KVM-Monitor 1   510  and KVM-Monitor 2   812 , includes a dedicated USB microcontroller  1010  integrated therein. Connected devices, such as PC 1   520  and PC 2   522 , may be used to relay events between those controllers. Again, the USB ports of the two monitors may be chained together via the USB connection  550 . However, there are no dedicated USB ports on each monitor, and the keyboard  530  and mouse  540  may be connected to any USB port of the two monitors. For example, instead of having the keyboard  530  and mouse  540  connected to KVM-Monitor 2 , as illustrated in  FIG. 7A , these input devices may be connected to KVM-Monitor 1 , as illustrated in  FIG. 8A . 
         [0055]    The microcontroller  1010  in each of the KVM-monitors  510  and  812  has access to and control over the LCD video input switching (as performed by the video switch  1012 , which is similar to the DVI switch  824  or  832  in  FIGS. 7B and 7D , for display on the LCD  1014 ). The controller  1010  is located on the downstream side of the monitor&#39;s integrated USB hub  1020 , which may include an extra USB port to accommodate the controller  1010 . The controller  1010  is also responsible for the upstream USB connectivity, via the USB switch  1022  on the upstream side of the hub. 
         [0056]    According to a further example, one or both of the monitors  510  and  812  includes intended USB master functionality. In this example, either or both of the monitors  510  and  812  may assume the role of the USB master and thus may control on the downstream devices. The USB master functionality may be stored on a computer-readable medium as software. 
         [0057]    With reference now to  FIG. 9 , there is shown a diagram  1100  in which a dedicated communication link  1150  is added between monitors  510  and  812 , which is an alternative to using a USB connection for inter-monitor communication as depicted in  FIG. 7A . As such, each of the monitors  510  and  812  includes a dedicated interface for enabling the dedicated communication link  1150  between the monitors  510  and  812 . The dedicated communication link  1150  may adopt one of the low-cost serial data transfer standards to create the data path (e.g. I2C, SPI, RS-485 or 1-wire), or it may use USB or another direct data connection method. Hence, each KVM-monitor  510 ,  812  includes additional connectors (for link input and output) for such a wired link  1150  that serves to simplify the data transfer process (without interfering with or modifying the USB/KVM chipset in each monitor). Furthermore, numerous monitors may be chained together using either a common electrical connection (e.g., as in the case of 1-wire bus solutions) or as a series of shorter one-to-one links (e.g., as in the case of SPI solutions). Examples of these arrangements are shown by the quad-display examples  1200  and  1260 , respectively, in  FIGS. 10A and 10B , which show KVM-monitors  1210 ,  1220 ,  1230 , and  1240  chained together by dedicated wired links  1150 . Each of the KVM-monitors  1210 - 1240  is similar to the KVM-monitor  510  described earlier. Also, multiple devices, such as PCs may be connected to one or more of the KVM-monitors. For simplicity,  FIGS. 12A-B  only show one PC  1250  connected to one of the KVM-monitors. In one embodiment, different colored and shaped connector types for the “in” and “out” ends of these monitor links may help to avoid user configuration errors. 
         [0058]    The dedicated communication link  1150  allows the KVM-monitors  1210 - 1240  to act as peers; thus, user-input changes to any one monitor may be propagated to all of the other connected monitors. The dedicated communication link  1150  also provides an option to connect multiple sets of keyboard and mouse pairs, each to a different monitor, to allow the user to switch between them. Additionally, by placing connectors on each side of the monitor, the monitor links may provide information regarding the relative location of each monitor and propagate this information back to the host PC. Various manners in which the respective locations of each of the monitors  1210 - 1240  may automatically be identified are described in greater detail herein below. In one regard, therefore, the respective locations of each of the monitors may automatically be identified, which eliminates the trial-and-error approach to multi-monitor configuration, allowing the monitors to inform the host of their spatial relationship with respect to each other on the desktop (or other setting). For example,  FIG. 10A  shows four KVM-monitors  1210 - 1240  in a horizontal (or single-line) distribution, and  FIG. 10B  shows a tiled (2×2) configuration. In each spatial configuration, the inter-monitor connections via the dedicated wired links to respective connectors on the KVM-monitors provide the host PC  1250  with information identifying their aggregated configuration. This allows the host PC  1250  to modify the distribution of video signals to each display, according to their relative position. In addition, it may be possible to use the same data to provide approximate location information for attached peripherals, for example USB microphones, speakers and webcams. Such data may allow auto-configuration and re-direction of their behaviors. For example, two identical USB speakers may be placed to the left and right side of the KVM-monitors, with some speakers acting as both a right speaker for one monitor and a left speaker for an adjacent monitor. Then, left and right channel audio may be automatically assigned to each speaker based on monitor switching. 
         [0059]    An alternative to the dedicated wired solution may be implemented by using short range wireless communications, whereby each KVM-monitor may have integrated therein one or more wireless transceiver IC (Integrated Circuit) chips.  FIG. 11  illustrates a diagram  1300  of a multi-monitor arrangement that uses proximity wireless communication  1350  as a dedicated communication link between each monitor, in accordance with one embodiment. This proximity wireless communication may be facilitated by NFC (Near Field Communications), RFID (Radio Frequency Identification), or other radio frequency or modulated light technologies, which have evolved to allow bi-directional data flow between pairs of closely located active transducers. 
         [0060]    In one embodiment, proximity data link antennas may be deployed or mounted along both sides of a monitor enclosure. Auto-detect functionality may operate to determine the presence of an adjacent monitor and allow input switching and other parametric data to be shared between the monitors. As with the use of dedicated wired links discussed above, the wireless communication may be independent of the current state of the host PCs. Consequently, KVM switching may be initiated by the user selecting an input selection button or an input selection in an on-screen control panel of any of the connected monitors, or optionally by entering an appropriate keyboard key-press sequence. Many existing standardized low power RF protocols may be used to implement the aforementioned wireless communication links between KVM-monitors. 
         [0061]      FIG. 12  illustrates a diagram  1400  of a multi-monitor arrangement, in which each monitor is equipped with Bluetooth™ capability (e.g., a Bluetooth™ radio chip) for wireless communication  1450 , in accordance with one embodiment. As illustrated, the KVM-Monitor 1  ( 510 ) is the Bluetooth™ master and may be USB connected to one or more host PCs, PC 1  ( 520 ) and PC 2  ( 522 ), via a 2×2 cross-point switch. This allows the upstream USB signals to be connected to either the internal multi-port USB hub or the internal Bluetooth™ module of the monitor. Other USB routing options may be implemented to allow the host PCs to access both the USB hub and the Bluetooth™ functionality in the monitor. KVM-Monitor 2  ( 812 ), which is not connected via USB to either host PC, becomes a Bluetooth™ slave, as do the keyboard  530  and mouse  540 . These wireless communication links create a network (Personal Area Network) connecting these input devices and the KVM-monitors  510 ,  812  to one of the selected PCs. However the Bluetooth™ controller in KVM-Monitor 1   510 , as the master, controls the PAN communications and can interpret KVM selection requests from any monitor input buttons or from keyboard key-press commands, regardless of the connected PC status. As in the previously described cases, the Bluetooth™ master collates status information for all the grouped devices and issues commands to switch all of these devices to the appropriate state. 
         [0062]    Accordingly, various embodiments as described herein provide an integration of the KVM functionality into display monitors at marginal cost increase, when compared to non-KVM monitors. This cost increase is more than offset by the increased usability and marketability of KVM-monitors. For example, the various embodiments described herein provide solutions that address a user&#39;s need or desire to share devices in a multi-computer and/or multi-monitor configuration. They also enable multiple monitors to operate in a synchronized manner by sharing status information and optionally other display parameters (brightness, contrast, color balance, etc.), power settings (on-off), etc., while providing the user with a much simpler interface and ergonomic overhead. Synchronization between the multiple monitors may include, for instance, changing the brightness on one monitor causes the brightness in another monitor to change to an identical setting. As another example, the synchronization may be defined to include that a change on one monitor causes the same relative change to occur in another monitor. Linking multiple devices to form a desktop ensemble of input/output devices also allows a single user action (e.g., key-press sequence or button press) to perform simultaneous keyboard, mouse and display switchover between multiple source machines. 
         [0063]    While the description presented above has focused on USB and DVI connections, it should be apparent that the same techniques would apply in configurations where video and peripheral signals are combined in a single connector or cable. In addition, although particular attention has been given to switching two-dimensional video outputs for visual monitors, exactly the same descriptions presented above would apply for audio, tactile, or 3D output devices. 
         [0064]    What has been described and illustrated herein is an embodiment along with some of its variations. The terms, descriptions and figures used herein are set forth by way of illustration only and are not meant as limitations. Those skilled in the art will recognize that many variations are possible within the spirit and scope of the subject matter, which is intended to be defined by the following claims—and their equivalents—in which all terms are meant in their broadest reasonable sense unless otherwise indicated.