Abstract: Memories are provided for correction signal values respectively for a hue signal, a saturation signal and a luminance signal derived from a digital color television signal. Each of the memories consists of two memory units which are alternately used for storing new correction signal values and for reading out previously stored correction signal values. The corrected signal values are modified by a key signal, if present, in each case and are then supplied to calculation circuits to each of which a signal derived from the saturation signal is applied. The resulting fully corrected hue and saturation signals are converted back into color difference signals, but the finally corrected luminance signal requires no conversion. The raw correction signal values are supplied from a computer into which control magnitudes can be entered to produce them. These control magnitudes can be used to define corner points of a deflected line function from which the correction signals are derived.

Abstract: Circuitry for detecting and correcting errors in data words occurring in Reed-Solomon coded blocks contains a plurality of stages. One stage constructs syndromes in the data flowing through the blocks. Another stage detects erasures in the syndromes. Another stage applies a Euclid's algorithm withT.sub.s (x)={Q.sub.s-1 (x).multidot.T.sub.s-1 (x)}+T.sub.s-2 (x),R.sub.s (x)={Q.sub.s-1 (x).multidot.R.sub.s-1 (x)}+R.sub.s-2 (x),andI Q.sub.s-1 (x)=R.sub.s-2 (x)/R.sub.s-1 (x)wherein T.sub.s (x), R.sub.s (x), and Q.sub.s-1 (x) are polynomials representing the position of the error, its value, and a provisional value respectively, and R.sub.s (x) and T.sub.s (x) can be normalized with a minimal coefficient T.sub.s (0)=.delta. such that R(x)=R.sub.s (xi/.delta. and T(x)=T.sub.s (x)/.delta.. Another stage detects error positions X.sub.k and values Y.sub.k by conducting a Chien zero-root search in conjunction with ##EQU1## wherein T'(X.sub.k) is the first derivative of T at a place x.sub.k.

Abstract: Memories are provided for correction signal values respectively for a hue signal, a saturation signal and a luminance signal derived from a digital color television signal. Each of the memories consists of two memory units which are alternately used for storing new correction signal values and for reading out previously stored correction signal values. The corrected signal values are modified by a key signal, if present, in each case and are then supplied to calculation circuits to each of which a signal derived from the saturation signal is applied. The resulting fully corrected hue and saturation signals are converted back into color difference signals, but the finally corrected luminance signal requires no conversion. The correction signal values are supplied from a computer into which control magnitudes can be entered to produce them. These control magnitudes can be used to define corner points of a deflected line function from which the raw correction signals are derived.

Abstract: In a magnetic tape transport device having supply and take-up reels and tape guide elements, as well as a scanner, there is engaged with the tape on each side of the scanner a tape tension roller on the free extremity of a tape tension lever which is subjected to torque at its pivot by a d.c. motor for maintaining the desired tension of the tape. An angular position indicator is connected to the pivot of the lever and a regulation loop is provided for controlling the tape tension in a manner consistent with the tape speed. A capstan drive of the tape is not necessary.

Abstract: A digital color television signal has its chrominance component, which is in the form of color difference signals, resolved into color hue and color saturation signals which are used to address a function memory which provides a pair of correction signals that are supplied to calculator circuits which respectively receive the color hue signal, the color saturation signal and the luminance signal as well as predetermined control signals previously stored which relate to the color sectors adjacent to the color sector in which the color hue signal is located. The calculation circuits respectively supply corrected color hue, color saturation and luminance signals. The color hue signal is additively corrected by a color hue correction signal and the color saturation signal is multiplicatively corrected by a saturation correction signal.

Abstract: For oblique track scanning of magnetic tape which is looped around a two-part drum (1, 2) separated by a gap (5) in which magnetic heads (11) affixed to a headwheel revolve, the rotary transformers connecting the magnetic heads on the headwheel to fixed parts of the scanning device are provided by inner and outer magnetic core rings in which windings are embedded for a number of transformers. One group of these rotary transformers (18, 19) is located above the headwheel disk structure (10, 25) in such a way that outer magnetic core rings are fixed in a bore of the fixed upper drum (1) and inner magnetic core rings (19) are affixed to a seating shell (25) that connects the headwheel disk (10) to its driving shaft.

Abstract: For reducing the d.c. component of a digital signal in which a good many data words are put together in data blocks each having the same number of words, a supplementary word is derived and is transmitted or stored along with the data words. The bit mix of the supplementary word contains information for shifting the word bit-mix range, defined in accordance with the d.c. component of various words of the data words in the data block. The bit-mix value of the supplementary word is derived by evaluation of the weighting of ASE-coded data words in the data block, this being done in a manner dependent on the standard deviation and an expected value or center of gravity of the data block. A difference value determined with respect to the center of gravity and the value of a middle level value of a data word represents the value of the supplementary word with which, by the use of the modulo-2 addition the digital signal is shifted in bit-mix value range.

Abstract: A tape drive mechanism for magnetic tape apparatus for tapes housed in cassettes has a pressure roller (29) at one end of a press-on lever (35) which is pivotally held on a drive shaft bearing (31) of a drive shaft (30) so that it can be inclined in a vertical plane. Another end of the press-on lever (35) has the guide cavity (37) in which a grade element (38) is held. The guide element is affixed at the end of a bascule lever (40) which is pivoted also on the supporting bearing (31) of the drive shaft (30). The bascule lever (40) is controlled by the progress of a tape threading operation of a tape loading device, the control being in the axial direction of the drive shaft (30).

Abstract: Video signals are supplied as component signals (in which the color signals are not correlated with a color carrier wave) and are stored in a frame memory and read out therefrom in synchronism with supplied reference signals. A FIFO memory is interposed ahead of the frame memory for delaying the video signals in such a way that they can be brought into synchronism with the horizontal phase of the reference signals. The system can be made to operate in a frame mode in which the field sequence and the timing of the synchronizing pulses always agree with those of the reference signal, in a field mode in which only horizontal sychronization is provided and the field sequence can be modified, a line mode in which the input signal is merely delayed into synchronism with the horizontal phase of the reference signal, and a delay mode in which a substitute reference signal is derived from the input signal itself, so that the memory is used merely for delay.

Abstract: A method of recording and/or playing back a data signal, in an apparatus in which a tape helically encircles a drum containing a headwheel, and the heads scan oblique tracks on the tape, features reduction of the tape velocity by a factor 1/n where n is a positive integer. Along with the tape velocity change, the static tracking angle between the tape and drum is correspondingly adjusted so that the heads will continue to scan along a standard track pattern or format. The data rate of data signals retrieved from the tape (e.g. high-date rate satellite transmissions) or of incoming data signals can be converted to a different data rate by intermediate steps of writing to a digital memory and reading back at a more desirable data rate.

Abstract: Synchronizing pulses are separated from a video signal played back from a magnetic tape recording. The individual synchronizing pulses are then inspected in a digital inspection circuit containing two generic array logic (GAL) units and a counter, operating in conjunction with a gate pulse generated from a electrically programmable read-only memory (EPROM) which is controlled by a counter reset by every validated synchronizing pulse. The inspection is in terms of phase and width of the synchronizing pulse. The pulses that pass inspection are utilized for the playback of the video signal, as are also other timing signals generated by the EPROM. The detection of a dropout in the playback demodulator interrupts the provision of inspected synchronizing signals and also prevents false clamping of the final sync separator, but clock pulses driving the counter that addresses the EPROM, together with a reset signal from the EPROM, maintain certain timing signals during the dropout.

Abstract: The magnetic tape video playback apparatus for a digital video signal regenerates the sample rate from the playback to operate a counter and detects the video data block numbers to permit an address generator to derive the more significant bits of addresses for a picture memory in which the video data signal is temporarily stored. The counter provides the less significant bits of the write addresses. The separated vertical sync pulses are counted in a second counter to provide time information for storage in a time data memory which is operated in parallel with the picture memory, using the write addresses from the already mentioned address generator. A reference sample rate generator operates a third counter which provides the read out addresses for the picture and time data memories.

Abstract: A system for focusing a zoom lens objective of a color television camera. A luminance or green video signal derived from a portion of the picture is full-wave rectified and then averaged. The sharpest focus corresponds to the highest value of that average. The signal is converted to digital form and processed by a microcomputer for automatic focusing control by finding the signal maximum with shifting of the lens focus setting. The video signal is stripped of its d.c. component before rectification, but is used with its full bandwidth.

Abstract: A scanning device for a magnetic tape recording and playback equipment of the oblique track type has a drive shaft (9) for a rotary head wheel (4) mounted in a duplex ball bearing (10) centered on the orbit plane of the magnetic heads which revolve on the circumference of the head wheel between the two halves of a tape-guiding drum. A support bearing (19) is affixed in the bottom of a housing (17) which houses the drive motor and is held in a downward extending socket at the bottom of the lower half of the drum. The housing can be tilt-shifted slightly for shifting the support bearing and then held, by three screws accessible from below, in the correct position for aligning the orbit of the magnetic heads in the gap between the two halves of the drum.

Abstract: A method of synchronizing digital data which includes periodic synchronization sequences. The first step in the method comprises determining the number of bit errors in relation to an ideal bit sequence in the synchronization sequence. A next step comprises using twice the chronological filtration from the resulting bit-error values to determine the timing of a synchronization sequence recognized in the digital data, allowing the data to be assembled block by block.

Abstract: A digital oscillator is built around an accumulator which is incremented by a predetermined number N of unit values at every pulse of a sequence of pulses of a reference frequency and the carry output of the accumulator is used to produce the output frequency. In order to eliminate the jitter of that output, the carry signal is supplied to a delay chain, from the output of which a delay is selected in a manner dependent upon the content of the accumulator during the presence of the carry signal in question at the output of the accumulator. The carry pulse times a D register in which the contemporary content of the accumulator is stored until the next carry pulse while being supplied to a calculation circuit for selecting the appropriate delay derived from the D register content and the number of units of accumulator incrementation in use at the particular time.

Abstract: A video noise reducer comprises a full picture memory and provides comparison of corresponding pixels of undelayed and delayed video signals, in which the delayed signal is fed back and mixed which is the undelayed signal at a controllable fader fading factor controlled by the absolute value difference between compared pixels subjected to filtering and other processing. In this noise reducer pixel comparison is elaborated to provide a signal designating the sign of the difference and a temporal (non-spatial) motion detector checks for the predominance of designations of one sign (and the rarity of designations of the other sign) in order to establish the presence of a fading procedure which must not be mistakenly interpreted as a detection of motion in the picture content. The temporal motion detector can be constituted so that isolated designations of a sign opposite to the preponderant sign of a succession of designations of the same sign cannot prevent the recognition of the presence of a fading procedure.

Abstract: Data signals recorded in oblique tracks on a magnetic tape, after they are picked up, preamplified and prefiltered, are rectified and converted to digital values representative of amplitude in respective segments distributed over track lengths. For each segment position in a track, the values are averaged and inverted by a ROM and stored in a RAM at track segment addresses. The values thus stored are converted into analog form and then used as multipliers in a multiplication stage following the preamplification and prefiltering. The output of the multiplier can readily be shaped into unambiguous data signals for further processing.

Abstract: When two color television standards prescribe the same horizontal scanning frequency but different color carrier frequencies, one of them, for example, requiring a frequency providing a one-half line offset to the horizontal scanning frequency (NTSC Standard) and the other requiring a three-quarter line offset (PAL-M Standard), each color carrier frequency being locked to the common line frequency, a modified phase locked loop circuit makes it possible to synchronize the color carrier frequencies to each other. The oscillator at the color carrier frequency of one standard has its output compared, in a phase comparison stage, with the color synchronization signal of the other standard. The output of the phase comparison stage is supplied to a sample-and-hold circuit which is sampled during the presence of that color synchronizing signal in every fourth line.

Abstract: For reliable playback of digital video signals in slow-motion operation over a wide range of slow-motion speeds, auxiliary playback heads are positioned closely behind normal playback heads and offset by half a track width therefrom. Each of the playback heads have a circuit for regenerating clock and data signals which includes a PLL circuit and all of the PLL circuits have an output for the signal that shows whether the PLL circuit is locked in or not. The lock-in signals are supplied to first address inputs of an ROM which has a principal output showing whether the normal playback heads or the auxiliary playback heads have the larger number of locked-in PLL circuits and the group of playback heads having that larger number of locked-in PLL circuits is selected for having the data and clock signal outputs passed on to playback channels for further processing. The control of the switching circuit is improved by having auxiliary outputs of the ROM fed back to second address inputs thereof.