Robert Boschgmbh

Hubert Foerster

Josef Sochor

Winfried Horstmann

Richard Heinz

Reinhard Kutzner

Andreas Ilmer

Digitalized audio signals of a plurality of channels are stored blockwise in each channel and then recorded blockwise in repeating channel sequence in similarly situated portions of successive oblique tracks in which are also recorded concurrent video signals, but the recording of a channel block is skipped once per picture field, so that an integral number of channel sequences will record all the audio channel information for a period equal to a picture field. In the video track where audio recording is skipped, other information may be recorded. The read-out rate of the channel blocks is slightly accelerated so that the track skipping loses no information. Consequently, the recorded signals can be cut in, or cut off, or edited at any frame end without loss of registry of the audio channels.

Method and apparatus for recording digitally coded television signals

Color television signals are split up to provide a luminance signal and a chrominance signal. These are recombined in a manner designed to reduce the frequency bandwidth and, furthermore, time-subdivision is used to distribute signals for recording between two channels, with time expansion being provided in each channel before recording each channel on a separate track on the recording medium. In playback, the signals of the separate channels are time-compressed and then sequentially switched back into the original signal sequence. The time-expansion and distribution among channels can be performed after the color television signal has been rearranged to occupy smaller bandwidth or the components of the television signal can be separately time divided, distributed and time expanded in the recording technique, with the converse signal processing being performed in playback.

Method and apparatus for magnetic tape recording of color television

The invention relates to a method of recording a television signal of the kind in which the signal is recorded on a relatively slowly moving tape in a plurality of inclined tracks by a plurality of recording heads carried at the periphery of a head wheel rotating at a relatively high speed in a plane non-parallel to the direction of tape motion. The head wheel executes m complete revolutions for each n complete television pictures, where the ratio m/n is non-integral, and control signals having a frequency of 1/n of the picture frequency are recorded along a longitudinal control track by a fixed head. For recording signals according to the 625 line European standard, m is chosen to be 25 and n is chosen to be 2. For the U.S. 525 line standard, m is 21 and n is 2. In both cases 25 lines per track are recorded.

Method of recording television signals

Since frequency modulated signals such as color television signals are subject to amplitude changes as well as timing changes if the playback speed is not the same as the recording speed, a variable gain amplifier is provided. The gain of the variable gain amplifier is controlled by an error signal which corresponds to a measured difference between the recording and playback speed. The measured difference is derived from a phase comparison of separated color bursts and of the same bursts delayed by one line period. The amplitude corrected signals at the output of the variable gain amplifier are also applied to an amplitude measuring stage 16 whose output in turn controls the frequency characteristic of a filter filtering the color television signals prior to demodulation.

Playback system with amplitude correction for frequency modulated signals

Successive picture fields in normal operation are successively written into a one-field memory and displayed by nondestructive read-out. A stop order stops the tape while the last recorded picture field is continuously displayed and backs up the tape to a point from which it can be restarted to store either the next preceding or the next following picture field, according to the next order entered into the equipment. An address memory is supplied with addresses read off the tape by a counter roller and a timing mark reading head. A stop order interrupts the advancing of the address in storage by the tape advance reading head, causing the tape to be stopped and backed up at the end of memorizing the picture field being reproduced. A forward step or backward step order increments or decrements the address memory and restarts the tape, and when the addressed picture field is reproduced, it is stored in the memory, after which the usual stop and back-up automatically takes place. An order for resumption of progressive television picture reproduction can also be supplied to the system.

Method and apparatus for stop frame reproduction in television picture

Furnishing a signal having an amplitude corresponding to the difference between the recording and playback speed of a tape recorded color television signal, the phase of the color burst of two successive lines is compared. When the speed difference includes a known difference such as, for example, for slow motion reproduction, a compensating delay is added to the single line delay of the known apparatus and simultaneously a DC voltage corresponding to the so-added delay is added to the error signal derived from the phase comparator. The additional delay and the additional voltage for the error signal are automatically inserted into the circuit by ganging a switch or potentiometer for the additional delay and for the additional voltage to the speed control for the tape drive.

System for generating an error signal indicative of differences between

In order to provide fast- and slow-motion reproduction of video signals a tape is played back at a different velocity, at which the scan traces provide acceptable signals for only a portion of each track at a time, the acceptably picked-up picture lines of these track portions are temporarily stored (others being excluded) and then played back under conditions satisfying television reception standards, in an order determined by an address made up of the line number and a track and field identification provided in response to track and field beginning pulses recorded on the tape. The address can be recorded together with the video signals or can be generated by counting means during the reproduction of the video signals. The tape transport speed is automatically adjusted slightly, if necessary, with respect to the speed setting, to avoid duplicate storage of corresponding lines in successive fields at the expense of omission of other lines. Where it is satisfactory to limit the slow-motion and fast-motion tape speed to a number of particular values, the temporary storage and playback can be controlled by a read-only memory that has its content selected by the tape speed setting.

Method for fast- and slow-motion reproduction of video signals stored in

A color TV signal is recorded on an information carrier and includes a luminance component which occupies a predetermined luminance frequency range and a modulated chrominance subcarrier. In a conventional color TV signal, the modulated chrominance subcarrier occupies a first chrominance frequency range having a predetermined location relative to the luminance frequency range. However, the modulated chrominance subcarrier is assigned a different second frequency range which has the advantage that the modulated chrominance subcarrier in such range is easier to record. A color TV picture is to be reproduced from such recorded color TV signal. Firstly, there is introduced into such color TV signal a corrective phase shift bringing the signal into synchronism with a studio synchronizer. Only thereafter is the modulated chrominance subcarrier frequency-translated from the second back to the conventional first chrominance frequency range to thereby form a conventional color TV signal.

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Darmstadt, Germany

Hubert Foerster