Abstract: The invention concerns a method of time-correcting a digital switching signal. To derive a switching signal from a television signal in conventional analog technique, the television signal is passed through a threshold value device which provides the switching signal when the threshold value is exceeded. In digital processing, however, this can give rise to faults since the exceeding of the threshold value is not recognized until the following scanned value of the digital television signal so that the switching signal is delayed relative to its true position. To avoid this a time correction signal is formed which corresponds to the amount by which the actual switching signal is delayed relative to its true position, and this correction signal is used to produce a series of control signals which effect a progressive switching of the digital signal.

Abstract: The alternate line first picture field of a television picture frame is delayed for one line scan period and the delayed signals are averaged with the currently picked up signals to provide a second field of interpolated lines. Each recorded field is played twice and, for the first playing, a switch actuated at half the vertical scan frequency furnishes the delayed signals to the picture reproducing circuits, while for the second playing of the same field from the record, the averaged signals are supplied to the picture reproduction circuits. For color television signals, only the low-frequency components are processed in the foregoing manner, and the high-frequency components are separated by a frequency dividing network ahead of the delay circuit and added back to the processed low-frequency signals for provision to the picture reproducing circuits.

Abstract: To transmit color video information from one point to another within a color television studio complex, particularly for distribution of source signals which are intended to be processed in a digital mode at another location in the studio, the information is transmitted in form of a color television signal comprising a luminance component having a given frequency range and a carrier frequency chrominance component having a frequency range outside that of the luminance component, the chrominance component simultaneously obtaining the full color information for the luminance component. The selected mode permits the ready separation of the luminance and chrominance components without perceptible quality losses, and recording and cutting processing.

Abstract: 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.

Abstract: 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.

Abstract: A method of delaying a signal N period lengths of a timing signal is disclosed using two shift registers which have capacities y and z, each less than N, but which have a total capacity greater than N. The signal to be delayed is fed to a first shift register until that shift register is full. The signal is later fed to the second shift register. When N bits of information have been recorded by the shift registers, the first shift register is again inputted causing an output which corresponds to the first data bits of the signal. Thus, there is stored in both registers y+z-N bits of common data during each cycle. This cycle is repeated for each N periods of the timing signal, thereby resulting in the storage of N data bits by a plurality of shift registers which each have a capacity less than N which have a total capacity greater than N.

Abstract: A comb filter filters the luminance signal and a difference signal indicative of the difference in signal content between two sequential lines. A low-pass filter furnishes a low frequency luminance signal having only the low frequency components of the luminance signal. The low frequency signal is applied to a horizontal aperture correction circuit which furnishes substitute high frequency signals. The low frequency luminance signal and the substitute high frequency signals are applied to one input of a fade-in fade-out circuit whose other input receives the luminance signal. The ratio of signals at the output of the fade-in fade-out circuit is controlled by a correlation signal derived from the difference signal. In the digital embodiment, the fade-in fade-out circuit receives the luminance signal and the substitute high frequency signals only and the low frequency luminance signal is added to the output of the fade-in fade-out circuit.

Abstract: 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.

Abstract: A process and associated apparatus for digitally clamping pulse code modulated video signals is disclosed, including four separate preferred embodiments. The disclosed process first requires that during each horizontal scanning interval a difference between the binary value of the pulse code modulated video signal and a predetermined nominal binary value be determined. This difference is then arithmetically averaged with at least one similarly determined difference obtained during a prior horizontal scanning interval to obtain a binary correction value. The binary correction value is then added to the binary value of the pulse code modulated video signal which is to be clamped outside the horizontal scanning interval in the active range of a horizontal period.

Abstract: A head wheel is rotated at a predetermined, essentially constant speed within a tape cylinder over which a tape is guided in a spiral path, on which video signal tracks are recorded in inclined track portions. The instantaneous position of the head wheel is determined, for example by a tacho generator applying signals to a counter, phase-synchronized by the outputs from the head wheel tacho generator.

Abstract: 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.

Abstract: Color T.V. signal information is transmitted from a receiver into a recorder, from a transmitter to a receiver, from a color T.V. camera into a transmitter, or the like. The luminance component and the chrominance component are alternately applied to an analog-to-digital converter, during alternate respective field-periods (half-frame periods) of the T.V. signal. Produced at the output of the converter is a signal in which the digital chrominance information alternates with the digital luminance information during different respective field-periods of the T.V. signal. Although a single analog-to-digital converter can be used, the sampling frequency for the analog-to-digital conversion of the two different components can be of different respective values.

Abstract: An apparatus for delaying a signal n period lengths by the use of two shift registers which have capacities less than n but which have a total capacity greater than n. The signal to be delayed is fed to a first shift register until that shift register is full. The signal is then fed to a second shift register. Timing signals which control the shift registers' receipt of information are properly blanked in order to allow this result. When n bits of information have been recorded by the shift registers, the first shift register is again inputted causing an output which corresponds to the first data bits of the signal. While the first shift register is receiving and outputting the second cycle of information a pre-determined number of data bits are fed to the second shift register to fill the register. This cycle is repeated resulting in the storage of n data bits by a plurality of shift registers which each have a capacity less than n which have a total capacity greater than n.

Abstract: A binary encoded signal which is to be clamped at a desired binary value is simultaneously applied to a digital subtractor and a digital adder. The digital subtractor subtracts the difference between the desired binary value and the value of the binary encoded signal. The resulting difference is applied to a storage flip-flop circuit having a switching pulse input which receives a periodic signal. The flip-flop transfers the last received difference until the periodic signal is received causing it to transfer the latest received difference. A binary adder adds the output of the storage flip-flop to the binary encoded signal. This results in a corrected clamped binary encoded signal.

Abstract: The invention provides an apparatus for producing video frequency color value signals which correspond to a desired arrangement of vertical or horizontal color bars on a television screen. In the case of vertical color bars the apparatus derives during each line period an identical series of pulses having a multiple of the line frequency. Each series of pulses is applied to a binary counter which provides as output a sequence of sets of binary signals. This sequence of sets of binary signals is translated by a pre-programmed store into a further sequence of sets of binary signals, these latter sets of signals being applied to a digital-to-analogue converter adapted to derive therefrom corresponding sets of color value signals. Each set of color value signals defines a differently colored line segment.

Abstract: A color television signal is divided into a luminance signal component Y and two color difference signal components R--Y and B--Y. In differential pulse code modulation for transmission and demodulation after reception, the color difference signals are coded and decoded in a time multiplex mode respectively by a single coder and a single decoder.