Abstract: A television signal includes a video signal having at least luminance information and a signalling bit stream for conveying static control information bits relating e.g. to at least an aspect ratio of the video signal, in which a plurality of bits of an additional data signal are distributed over at least one bit of the signalling bit stream per frame of the video signal, whereby the signalling bit stream contains at least one varying bit in addition to the static control information bits.

Abstract: Method of transmitting signals between communication stations via a network, in which a central control station is adapted to transmit a picture of a virtually real ambience to each connected station. In the picture, connected stations are represented by objects which can be displaced by the user of the corresponding station. Other stations such as information sources are represented by stationary objects in the form of buildings. As soon as objects touch or overlap each other, an actual communication connection (for example a telephone conversation, a database consult, a transaction) is established between the corresponding stations. A "chat box" application is also provided, with the particular property that the extent of interaction between conversation partners is dependent on the mutual distance between their corresponding objects in the picture.

Abstract: A three dimensional projection television system in which the screen of the receiver alternatively receives a television picture field as polarized by polarizing apparatus and a television picture field which is orthogonally polarized with respect to the fields polarized by the polarizing apparatus. Also disclosed in a receiver for use in such a system. The receiver includes three projectors each projecting through a polarizer and an individual electro-optical crystal device.

Abstract: A movement-adaptive processing circuit for an interlaced video signal has a selection circuit (5) which passes on to its output (21) one of the three video signals applied to its inputs (3, 9, 11) and which signals substantially correspond to three position-sequential lines of two consecutive fields when this signal has an amplitude which is closest to the mean amplitude of these three video signals. The processing circuit may be used many types of circuits such as, for example, in line or field number conversion circuits, noise suppression circuits, DPCM decoding circuits, vertical contour correction circuits and still-picture display circuits of video record players.

Abstract: Arrangement for receiving and processing digital signals in teletext or associated systems, comprising a picture store and a background store, the background store being arranged immediately after the source for the digital input signals such that output signals of the background store can be applied to the customary input circuit for further processing, while the picture store is arranged after this input circuit. The background store can store at least two but preferably a larger number of pages. Because of this implementation the waiting times occurring when new pages are requested are reduced to zero or substantially zero after the first request, while no additional control actions by the user are required.

Abstract: In a television receiver, comprising a tuning portion (1) which operates in time-division multiplex and a first memory circuit (41) for storing sub-picture information from different transmissions obtained during a tuning cycle, a second memory circuit (57) is provided for acquiring the sub-picture information from the first memory circuit (41) in one single operation and for displaying (at 65) during a next tuning cycle a composite picture in which no change of picture content occurs.

Abstract: A movement-adaptive transversal-recursive noise suppression circuit for a television signal can be provided in a simple way with only a single control system (19) for changing from transversal to recursive filtering while maintaining optimum noise suppression. The circuit includes a first combining circuit having a first input for receiving the television signal, a delay circuit coupled to an output of the first combining circuit and a second combining circuit having a first input coupled to an output of the delay circuit and a second input coupled to the output of the first combining circuit, the output of the delay circuit being also coupled to a second input of the first combining circuit, and an output of the second combining circuit being the output of the noise suppression circuit.

Abstract: In a television circuit arrangement for field and line frequency doubling and picture part magnification (zooming), in order to obtain the frequency doubling, information is written, alternately, into two field memories (M1, M2) during a field period having line periods at a given writing speed (clock frequency fc), whereby the reading from the field memories takes place at twice the writing speed. For a picture part magnification to be carried out in a simple manner, a magnification control circuit (TG, S3, S4, S11, S12) having a clock signal change-over circuit (S3, S4) is provided, as a result of which during writing, a higher writing speed (clock frequency 2fc) than the said given writing speed (clock frequency fc) is used during a part of the field periods and of the line periods, which part is substantially inversely proportional to the ratio between the higher writing speed and the given writing speed.

Abstract: In a series-parallel-series memory circuit (3) which requires a write clock signal (at 19), a transfer clock signal (at 25) and a read clock signal (at 31), it is sufficient, because a clock signal processing circuit (23) is provided, to apply only two clock signals (to 33 and 35). Using a gate circuit (41), it is possible to obtain from one clock signal (applied to 35) additional information, which is provided by means of pulse duration variation, for adapting the time delay of the memory circuit (FIG. 1).

Abstract: In a field number conversion circuit, the mutual positions of the horizontal and vertical synchronizing signal pattern in a field of the television signal to be converted are measured by means of a measuring circuit (201) and these mutual positions are adequately transferred by means of a coupling circuit (203) to a corresponding field in the converted television signal. Reading the field memories (125, 127) used during the conversion operation is preferably effected at a clock frequency (at 53) which is not coupled to the clock frequency (at 23) used during the writing operation.

Abstract: Movement detection in a PAL television signal is effected on that portion of the television signal which is located within the chrominance signal band. This portion (obtained via 3) is demodulated into color difference signals (11, 13) which are added (29) and subtracted (27). The subtracted signal is delayed for one picture period and combined (39) with the added signal. Then the absolute value is produced (45), so that a signal is obtained which only reports movement and does not interpret crosstalk from the luminance signal of a still picture to the chrominance signal as movement.

Abstract: A color television display device comprising a plurality of picture display tubes for displaying a color television signal. In order to eliminate a flicker effect which particularly occurs for unsatured colors at high luminance, the vertical deflection of a first group of the display tubes as well as the video signals applied thereto are delayed by the same time delay with respect to a second group of the display tubes.

Abstract: A field-frequency doubling circuit for a television signal having two field memories (23, 29) may alternatively be employed as a picture memory for the television signal when it is slightly extended by providing a re-write circuit (9, 11) and an adapted output circuit (17, 47) (FIG. 1). This picture memory may be included in, for example, a noise suppression circuit or a movement detector.