Patent ID: 7685336
Filing Date: 2010-03-23
Classification: G06F

Abstract:
1. A keyboard-video-mouse (KVM) switch for connecting a plurality of computers and plural sets of user input and display devices, the KVM switch comprising: a server interface connected to the plurality of computers, wherein the server interface supports a first visual interface and a second visual interface and is configured to receive a video signal from the plurality of computers in a first format through the first visual interface or in a second format through the second visual interface; a client interface connected to the plural sets of user input and display devices, wherein the client interface supports a third visual interface and a fourth visual interface and is configured to supply a video signal in the first format through the third visual interface or in the second format through the fourth visual interface; a switch circuit, coupled between the server interface and the client interface, configured to route paths among the computers and the sets of user input and display devices; a first overlapping circuit configured to receive the video signal in the first format from the server interface and to overlap a first video overlapping image onto the video signal in the first format, thereby generating a first overlapped video signal in the first format; a first transmitting circuit configured to transmit the first overlapped video signal in the first format to one of the sets of user input and display devices through the third visual interface of the client interface; a first conversion circuit configured to receive the video signal in the second format from the server interface and to convert the video signal in the second format to a first converted video signal in an intermediate format; a second overlapping circuit configured to receive the first converted video signal in the intermediate format from the first conversion circuit and to overlap a second video overlapping image onto the first converted video signal, thereby generating a second overlapped video signal in the intermediate format; a second conversion circuit configured to receive the second overlapped video signal in the intermediate format from the second overlapping circuit and to convert the second overlapped video signal to a second converted video signal in the second format; and a second transmitting circuit configured to transmit the second converted video signal in the second format to one of the sets of user input and display devices through the fourth visual interface of the client interface; wherein the set of user input and display devices that sends an electrical signal to activate the overlapping circuits is different from the set of user input and display devices that displays the overlapped video signal.