Robert Boschgmbh

Hans-Peter Maly

Jurgen Heitmann

Gerhard Illetschko

Rudolf Wilhelm

A digital main store having a capacity of one field and a buffer store of much lower capacity upstream of the main store are so arranged that the buffer control controls the buffer store to compensate frequency differences between an input television signal and a reference signal. An address generator controls the main store to compensate phase differences between the two signals.

Synchronizing system for television signals

This invention concerns a method of reproducing, at a selectable magnetic tape speed different from that used during the recording, a video signal stored in a plurality of separate tracks inclined to the center line of the magnetic tape by means of a head wheel carrying peripherally arranged magnetic heads, wherein the addresses of reproduced lines of picture information are derived solely from the composite signal reproduced from the magnetic tape, wherein useful lines are read into respective locations of a picture store in accordance with these line addresses, and wherein the stored lines are read out from the store in a predetermined sequence. In the embodiment described the line addresses are derived by a counter to the counting input of which are delivered pulses which correspond to that of the horizontal synchronizing pulses taken from the magnetic tape, to the resetting input of which are delivered pulses which correspond to the vertical synchronizing pulses taken from the magnetic tape, and to a third input of which are delivered pulses the frequency of which corresponds to the frequency of cross modulation disturbances and each of which causes a change in the registered count by an amount which is determined by the registered count itself and whether the tape reproduction speed is greater or less than the recording speed.

Method and apparatus for the variable speed reproduction of a video

A circuit arrangement is described for the transmission of a digital data signal. The circuit arrangement is inserted as an asynchronous interface into the transmission path between digital data handling systems with differing clock frequencies f.sub.1 and f.sub.2. The circuit arrangement comprises a register 1 of D flip-flops for buffering the input data D.sub.1. The clocking of the register 1 is performed with a special clock signal f.sub.Inter, which is derived from a series circuit of edge controlled R-S and J-K flip-flops 3 and 4 respectively. The result is output data D.sub.2 synchronous with the frequency f.sub.2.

Circuit arrangement for the transmission of digital data

A method and apparatus for representing the amplitude curve of a selected portion of a video signal upon the picture screen of a video display device, at least the selected portion being in digital form and not requiring conversion to analog form prior to such representation. This is achieved by using the line structure of the line raster produced on the picture screen of the video display device as a digital-analog converter. The range of possible digital values for the individual picture elements of the selected line of the video signal are allocated as reference values to respective lines of the line raster, and during each line period of the line raster the digital values of the elements are compared in succession with the appertaining reference value. When during any line period of the line raster the compared values agree the picture screen is momentarily brightened, so that each picture element of the selected line is represented on the screen with a vertical displacement determined by its digital value, so that an amplitude curve similar to an oscillogram is produced having a horizontal time axis. In a further embodiment of the invention, arranged to display the amplitude curve of selected picture elements each taken from a respective line of the video signal, the reference values are allocated to respective columns of the line raster of the display device. The result is the production of an oscillogram on the picture screen having a vertical time axis.

Representing a video signal upon the picture screen of a video display

A complete analog color-T.V. signal is separated into a luminance component and a color component. Each component is digitalized and then written into an RAM sequentially using a first addressing schedule for the write-in. The information is then read-out using a different addressing schedule for the read-out. The thusly read out digitalized components are converted back into analog form and combined to form another complete analog color T.V. signal. This technique makes possible a variety of special effects, including horizontal and/or vertical image compression, the display of a half image and alongide it a mirror-symmetrical version thereof, the storage of four color T.V. images in a manner which is interleaved in both the x and y directions of the memory, and others.

Modification of T.V. image performed using ram storing the image content

An analog PAL color television signal which is to be encoded is passed through a comb filter to separate the signal into a chrominance component and a luminance component each having a carrier frequency. Each signal is then separately scanned at a rate which is directly related to the color carrier frequency (4.43 MHz) of the signal. The luminance signal is fed to a scanning and holding circuit which scans it at a rate of twice the color carrier frequency or 8.86 MHz. The chrominance signal is fed to a scanning and holding circuit which scans it at a rate which is one-half the color carrier frequency of 2.21 MHz. This scanning and holding of each component signal converts the signals into a corresponding PAM signal. Each PAM signal is then quantized and encoded in a PCM coder. The resulting signals are applied to a digital combiner which thereby produces a digital color video signal.

Method and apparatus for digitally encoding color video signals having

A digital system is disclosed for precisely located a television vertical sync signal. The precise location in time of a (k + 1)th pulse used for vertical synchronization is predicted, based on continuously observed past performance, as a function of time interval after the last or (k)th pulse used for horizontal synchronization.

Growing community of inventors

Darmstadt, Germany

Hans-Peter Maly