Abstract: Apparatus, systems and methods for generating a hybrid on screen display are described. A background image portion of a user interface is generated at a switching device. Video data representing the background image portion of the user interface is transmitted to a user station of a user console. The video data is modified at the user station as it is received using video data representing a user interface element that is specific to the user station. A customized user interface is displayed on a display device attached to the user station.

Abstract: Apparatus and methods for transmitting digital video data and auxiliary data over a four twisted wire pair cable, and systems using such apparatus, are described. A first, second and third digital video color signal and a digital video timing signal are transmitted using differential mode signalling over a first, second, third and fourth twisted wire pair of a cable. Auxiliary data is sent over a data channel using common mode signalling over a first pair of the four twisted wire pairs of the cable. A common mode choke can be used to add or remove a signal sent using the common mode signalling from a pair of wires also used to transmit one of the digital video color or digital video timing signals.

Abstract: A method and system for supplying a digital video signal from a source to a sink are described. The digital video signal includes digital video data for three different colors and a pixel clock signal, such as DVI and HDMI. The digital video data and the pixel clock signal are received at a transmitter which sends a signal representative of the frequency of the pixel clock signal over a cable connecting the transmitter and a receiver. Digital video data for three different colors is sent over three different twisted wire pairs of the cable to the receiver. A local pixel clock signal is generated at the receiver using the signal representative of the frequency of the pixel clock signal. The local pixel clock signal is used to process the received digital video data and recovered digital video data and the local pixel clock signal are output.

Abstract: A digital video signal has a frame rate and a resolution within a range of resolutions. If the resolution of the received digital video signal is in a lower resolution range then it is not compressed or if in a higher resolution range the video color data is compressed by a constant compression ratio. Frames of digital color samples are transmitted and frames of digital color samples are received at the same frame rate. The received compressed digital color samples are expanded by a constant expansion ratio when transmitted in a compressed format and not expanded if transmitted in the uncompressed video format. A digital video signal is output with a resolution the same as the resolution of the original digital video signal.

Abstract: Apparatus and methods for reducing cross talk between electrical ports are described. An electronic device comprises a housing for electronic circuitry and has a plurality of ports for connecting electrical devices. Each port includes a connector connected by at least one electrical connection to the electronic circuitry. A connector shield is arranged to provide an electrically conductive loop around which an induced electrical current can flow to reduce cross-talk between ports. A shielding can is part of the connector shield and includes a body formed of a folded sheet of electrically conductive material and an electrical contact for electrically connecting the body to a connector. A face of the body defines a first aperture shaped to receive the connector so that the shielding can may be arranged about the connector to form a part of the electrically conductive loop.

Abstract: A switching device for automatically sharing a pointing input device between a plurality of computers is described. The switching device includes an input for receiving relative pointer position data from the pointing input device and a plurality of outputs, each connectable to a respective one of a plurality of computers. A controller receives the input relative position data and converts the relative pointer position data to absolute pointer position data. Which of the plurality of computers to route input data to is determined based on the absolute pointer position data. Input data is routed to one of the plurality of computers so that a cursor position on a display device of the computer can be controlled by the pointing input device.

Abstract: There is provided video switching circuitry for use in a KVM switch and similar devices. Video signal switching circuitry can supply video signals from a one of a plurality of video sources connected to the circuit to a display device connected to the circuit. The high data signalling rate signals are converted into a greater number of lower data signalling rate signals for switching by a bus architecture. Also provided are video display systems in which analogue and digital video signals are switched synchronously to allow them to be displayed on common or separate display devices. Also described is a high-resolution monitor digital video data switching device.

Abstract: Apparatus and methods for reducing cross talk between electrical ports are described. An electronic device comprises a housing for electronic circuitry and has a plurality of ports for connecting electrical devices. Each port includes a connector connected by at least one electrical connection to the electronic circuitry. A connector shield is arranged to provide an electrically conductive loop around which an induced electrical current can flow to reduce cross-talk between ports. A shielding can is part of the connector shield and includes a body formed of a folded sheet of electrically conductive material and an electrical contact for electrically connecting the body to a connector. A face of the body defines a first aperture shaped to receive the connector so that the shielding can may be arranged about the connector to form a part of the electrically conductive loop.

Abstract: A method and system for supplying a digital video signal from a source to a sink are described. The digital video signal includes digital video data for three different colours and a pixel clock signal, such as DVI and HDMI. The digital video data and the pixel clock signal are received at a transmitter which sends a signal representative of the frequency of the pixel clock signal over a cable connecting the transmitter and a receiver. Digital video data for three different colours is sent over three different twisted wire pairs of the cable to the receiver. A local pixel clock signal is generated at the receiver using the signal representative of the frequency of the pixel clock signal. The local pixel clock signal is used to process the received digital video data and recovered digital video data and the local pixel clock signal are output.

Abstract: A video switch for allowing at least two users to view video data from respective ones of at least two video sources. The video switch comprises a switch for selecting one of the at least two video sources and at least one sampler connected to the switch. The sampler is for sampling video data from the at least two video sources. The video switch further comprises a controller for controlling the switch and sampler to select one of the at least two video sources and sample a frame of video data. An output is provided for transmitting video data to one of the at least two users. The output supports a maximum number of simultaneous users which is at least two, and the number of samplers in the video switch is less than the maximum number of simultaneous users. A video switch according to the present invention allows a sampler for capturing video data to be shared between at least two simultaneous users. This reduces the cost, size and complexity of the hardware required to implement a video switch.

Abstract: There is provided video switching circuitry for use in a KVM switch and similar devices. Video signal switching circuitry can supply video signals from a one of a plurality of video sources connected to the circuit to a display device connected to the circuit. The high data signalling rate signals are converted into a greater number of lower data signalling rate signals for switching by a bus architecture. Also provided are video display systems in which analogue and digital video signals are switched synchronously to allow them to be displayed on common or separate display devices. Also described is a high-resolution monitor digital video data switching device.

Abstract: A system, apparatus and methods for transmitting video and audio data over twisted pairs are described. A differential signal that contains video color information is transmitted over each twisted pair. Data representing digital samples of at least one audio signal is transmitted on two or more of the twisted pairs as a common mode signal.

Abstract: A switching device for automatically sharing a pointing input device between a plurality of computers is described. The switching device includes an input for receiving relative pointer position data from the pointing input device and a plurality of outputs, each connectable to a respective one of a plurality of computers. A controller receives the input relative position data and converts the relative pointer position data to absolute pointer position data. Which of the plurality of computers to route input data to is determined based on the absolute pointer position data. Input data is routed to one of the plurality of computers so that a cursor position on a display device of the computer can be controlled by the pointing input device.

Abstract: A video switch for allowing at least two users to view video data from respective ones of at least two video sources. The video switch comprises a switch for selecting one of the at least two video sources and at least one sampler connected to the switch. The sampler is for sampling video data from the at least two video sources. The video switch further comprises a controller for controlling the switch and sampler to select one of the at least two video sources and sample a frame of video data. An output is provided for transmitting video data to one of the at least two users. The output supports a maximum number of simultaneous users which is at least two, and the number of samplers in the video switch is less than the maximum number of simultaneous users. A video switch according to the present invention allows a sampler for capturing video data to be shared between at least two simultaneous users. This reduces the cost, size and complexity of the hardware required to implement a video switch.

Abstract: There is provided video switching circuitry for use in a KVM switch and similar devices. Video signal switching circuitry can supply video signals from a one of a plurality of video sources connected to the circuit to a display device connected to the circuit. The high data signalling rate signals are converted into a greater number of lower data signalling rate signals for switching by a bus architecture. Also provided are video display systems in which analogue and digital video signals are switched synchronously to allow them to be displayed on common or separate display devices. Also described is a high-resolution monitor digital video data switching device.

Abstract: A system, apparatus and methods for transmitting video and audio data over twisted pairs are described. A differential signal that contains video colour information is transmitted over each twisted pair. Data representing digital samples of at least one audio signal is transmitted on two or more of the twisted pairs as a common mode signal.

Abstract: Devices for reducing and determining the skew between colour video signals transmitted over at least two different video cables are described. A KVM extender including such devices is also described. The skew reduction device includes a plurality of video signal transmission tracks selectably connectable to each of the video cables to increase the video signal transmission path length so as to more closely matching the total video signal path length for each of the colour video signals. The skew determination device comprises a processing device, a signal generator for applying measuring signals to each of the video signal cables and signal detection circuitry to receive measuring signals transmitted over the video signal cables. Detection signals are output to the processing device which is programmed to determine an indication of the transmission path length difference between the video signal cables.

Abstract: A serial data routing device for use in routing serial data between a computer and a peripheral device. The data routing device includes a computer data converter which communicates data under the USB protocol with a computer and which converts data received from the computer into converted computer data. A peripheral data converter is also included which communicates data under the USB protocol with the peripheral device and which converts data received from the peripheral device into converted peripheral data. A data router is provided in communication with the computer data converter and the peripheral data converter and transfers converted computer data and converted peripheral data between them. It includes a data routing controller which controls the routing of the converted computer data and the converted peripheral data between the computer data converter and the peripheral data converter such that the computer and peripheral device operate as though directly connected by a USB bus.

Abstract: There is provided video switching circuitry for use in a KVM switch and similar devices. Video signal switching circuitry can supply video signals from a one of a plurality of video sources connected to the circuit to a display device connected to the circuit. The high data signalling rate signals are converted into a greater number of lower data signalling rate signals for switching by a bus architecture. Also provided are video display systems in which analogue and digital video signals are switched synchronously to allow them to be displayed on common or separate display devices. Also described is a high-resolution monitor digital video data switching device.