Patent ID: 8650344
Filing Date: 2014-02-11
Classification: G06F,G09G

Abstract:
1. A method for operating a KVM switch with independent on-screen display (OSD) and control channels through at least one operation and control device, the KVM switch comprising a switch circuit, an OSD control system unit and an OSD unit, the switch circuit comprising a computer video switching circuit for receiving video signals and synchronization signals from a plurality of computers and a switch control and processing chip for receiving the video signals and synchronization signals from the computer video switching circuit and calculating, processing and transmitting the video signal and synchronization signal of the selected computer to the computer video switching circuit, the OSD control system unit comprising an OSD control system chip which receives at least one functional instruction from the operation and control devices, converts the functional instruction to control command and transmits the control command to the switch circuit and the OSD unit, the OSD unit comprising an OSD video switching circuit and an OSD processing chip, the OSD processing chip receiving the control command and a background video signal from the OSD control system unit, calculating, processing and generating an OSD synchronization signal and an OSD menu video signal, and transmitting the OSD synchronization signal, the OSD image signal and the OSD background image signal to the OSD video switching circuit, the OSD video switching circuit performing the ON and OFF switching processing for the output of the OSD synchronization signal, an OSD menu video signal and OSD background video signal for displaying at a monitor, the method comprising the steps of: (a) the switch control and processing chip of the switch circuit of the KVM switch receiving a functional instruction or call from the operation and control device; (b) the switch control and processing chip of the KVM switch handing the OSD relevant control power over to the OSD control system unit, and then the OSD control system unit outputting switch signals to turn off the picture of the video signal and synchronization signal of the selected computer and starting the channel for OSD synchronization signal, OSD menu video signal and OSD background video signal; (c) the OSD control system unit of the KVM switch retrieving a pre-stored OSD background picture; (d) the OSD control system unit outputting the pre-stored OSD background video signal and the control command to the OSD processing chip of the OSD unit, and the OSD processing chip and the OSD video switching circuit transmitting the OSD background video signal, the OSD menu video signal and the OSD synchronization signal to the monitor for displaying; (e) the operation and control device inputting a functional instruction to select an OSD operation picture; (f) outputting the selected OSD operating picture to the OSD processing chip, and then transmitting it to the monitor; (g) the operation and control device inputting a functional instruction to the OSD control system chip of the OSD control system unit to control the OSD processing chip to stop the OSD operation and exit from the OSD background picture; (h) the OSD control system unit enabling the OSD video switching circuit to turn off the channel of the OSD synchronization signal, the OSD menu video signal and the OSD background video signal; and handing the control power back to the switch control and processing chip of the switch circuit of the KVM switch, and then the switch control and processing chip controlling the computer video switching circuit to switch back to the picture of the video signal and synchronization signal of the computer.