U.S. Philips Corporation

Telefunken

Arthur Heller

Klaus Schuster

Alfred Schaumberger

Friedrich Gierlinger

Friedrich Dollinger

A method of transmitting and decoding biphase coded signals individually representing separate data services and inserted in the line blanking interval of a video signal greatly increases the probability of avoiding the effects of anticoincidence errors. A unique start code is allocated to each of the data services prior to transmitting the video signal. The video signal is separated into the separate data services without field or line windowing. Every pair of biphase elements occurring after the start code is checked for anticoincidence errors, and all wanted bits are stored in a buffer memory. The wanted bits are transferred from the buffer memory to an output memory only when no anticoincidence error has occurred between the start code and the last wanted bit.

Sdystem for transmitting and decoding biphase data, in particular for VPS

A method of producing a modulated chrominance signal with suppressed carrier. A square-wave carrier signal and a color information signal in the form of a sequence of digitally encoded amplitude values are applied to a modulator arrangement. The clock frequency for the amplitude values is an integral multiple of the color carrier frequency and is phase-locked thereto. Each bit of the amplitude values is inverted during one half cycle of the carrier and not inverted in the subsequent half cycle. A first and a second value, respectively are added to the values obtained thus, these first and second values being calculated such that also for input and/or output signal values which are located at a distance from the drive mean values at the input and output ends a total carrier suppression is achieved for the desired input signal level. The modulated analog chrominance signal is available after digital-to-analog conversion.

Method of producing a modulated chrominance signal with suppressed

A television test line signal generator comprising a read-only memory which is read under the control of a clocked counting circuit, memory outputs being connected via a clocked buffer store to a digital-to-analogue converter, which is followed by a signal filter. The information in the read-only memory is programmed versus signal distortions following thereafter.

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Eichenried, Germany

Arthur Heller