Abstract:
A video recorder, includes: a filter for performing a comb-filtering operation and supplying a comb-filtered component of a video signal; controllable influencing apparatus for terminating the output of the comb-filtered component and activating instead, the propagation of the non-filtered component; transition detection apparatus for detecting a vertically extending transition and supplying characteristic information upon detection of such a transition; control information generating apparatus, arranged between the transtion detection apparatus and the influencing apparatus, for generating control information enabling the termination of the output of the comb-filtered component and the activation of the propagation of the non-filtered component for a period of time which is longer than possible by means of the characteristic information.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The invention relates to a circuit arrangement for processing a video signal which contains a brightness component and a color component and may include video signal segments representing vertically extending transitions in a visually observable rendition, the circuit arrangement comprising filter means for processing one of the two components of the video signal in conformity with the comb filter principle, the filter means comprising a direct branch and a delay branch, the direct branch propagating the processable component of the video signal essentially without delay, while the delay branch includes delay means for delaying the processable component of the video signal by the duration of at least one line, and also comprising combination means following the direct branch and the delay branch for combining the component of the video signal propagated essentially without delay and the delayed component of the video signal, and for outputting the comb-filtered component of the video signal, the circuit arrangement also comprising a switching stage following the filter means for further processing the comb-filtered component of the video signal, controllable influencing means for terminating propagation of the comb-filtered component of the video signal to the switching stage, and, at the same time, for activating propagation of this component of the video signal, in at least essentially non-filtered form, to the switching stage, and transition detection means for detecting a vertically extending transition, represented by at least one of the two components, and whereby, upon detection of such a transition, characteristic information is generated and applied to output means of the transition detection means, the output means of the transition detection means being connected to the controllable influencing means via connection means in such a manner that, when characteristic information is output via the output means, the controllable influencing means ensures termination of the propagation of the comb-filtered component of the video signal and activation of the propagation of this component of the video signal in at least essentially non-filtered form. 
     The invention also relates to a video recorder which includes a circuit arrangement for processing a video signal which contains a brightness component and a color component and may include video signal segments representing vertically extending transitions in a visually observable rendition, the circuit arrangement comprising filter means for processing one of the components of the video signal in conformity with the comb filter principle, the filter means comprising a direct branch and a delay branch, the direct branch propagating the processable component of the video signal essentially without delay, while the delay branch includes delay means for delaying the processable component of the video signal by the duration of at least one line, and also comprising combination means following the direct branch and the delay branch for combining the component of the video signal propagated essentially without delay and the delayed component of the video signal, and for outputting the comb-filtered component of the video signal, the circuit arrangement also comprising a switching stage following the filter means for further processing the comb-filtered component of the video signal, controllable influencing means for terminating propagation of the comb-filtered component of the video signal to the switching stage, and, at the same, for activating time propagation of this component of the video signal, in at least essentially non-filtered form, to the switching stage, and transition detection means for detecting a vertically extending transition, represented by at least one of the two components, and whereby, upon detection of such a transition, characteristic information is generated and applied to output means of the transition detection means, the output means of the transition detection means being connected to the controllable influencing means via connection means in such a manner that, when characteristic information is output via the output means, the controllable influencing means ensures termination of the propagation of the comb-filtered component of the video signal and activation of the propagation of this component of the video signal in at least essentially non-filtered form. 
     2. Description of the Related Art 
     A circuit arrangement of the kind set forth in the first paragraph and a video recorder of the kind set forth in the second paragraph are known, for example, from German Patent DE 40 22 923 A1. 
     In the known circuit arrangement and in the known video recorder, the output means, formed by an output of the transition detection means (consisting of a color difference recognition circuit), receives a characteristic pulse as the characteristic information from the transition detection means and is connected directly, via a connection lead, which is provided as the connection means, to the filter means which is formed by a simple comb filter and which receives the color component, so the color signal, of a video signal to be processed in order to subject the color signal to an operation for eliminating crosstalk by means of the filter means. In the known circuit arrangement, it is a problem that, upon detection of a transition extending vertically in a visually observable rendition, the color difference recognition circuit outputs a characteristic pulse whose duration essentially corresponds to only the duration of the transition, and that in dependence on this characteristic pulse, the influencing means (formed by an electronic switch in the delay branch of the filter means) ensures, only for the duration of this characteristic pulse, that the propagation of the comb-filtered color signal is terminated and that the propagation of the non-filtered color signal to a switching stage succeeding the filter means is activated, in that the influencing means provides for substantially complete suppression of the color signal delayed by means of the delay branch of the filter means. It has been found in practice that, despite such influencing of the filter means, a disadvantageous color signal delay occurs which has a disturbing effect, notably in the visually observable rendition of, in that case, horizontally extending color transitions, because it induces a shift of the color information in the vertical direction towards the lower end of the picture and the shift extends across every color transition of this kind. 
     SUMMARY OF THE INVENTION 
     It is an object of the invention to eliminate the described problems and to provide an improved circuit arrangement of the kind set forth in the first paragraph, and an improved video recorder of the kind set forth in the second paragraph, offering improved signal processing and, hence, a perfect visually observable rendition of the processed video signals. 
     In order to achieve this object, a circuit arrangement of the kind set forth in the first paragraph according to the invention is characterized in that control information generating means is inserted in the connection means between the transition detection means and the influencing means, the control information generating means receiving the characteristic information generated by the transition detection means, and generating, in dependence on the reception of characteristic information, control information which is applied to the influencing means and enables termination of the propagation of the comb-filtered component of the video signal and activation of the propagation of this component of the video signal in at least essentially non-filtered form, for a period of time which is longer than is possible by means of the characteristic information. Thus, using only a few additional means, it is achieved that for a period of time lasting several lines, the influencing means ensures influencing of the termination of the propagation of the comb-filtered component of a video signal and, instead, activates the propagation of the component of the video signal in non-filtered form, so that a component of a video signal which has been delayed by more than one line, for example, by the filter means but also by other means inducing a delay, does not have a disturbing effect on the visually observable rendition of a transition extending in the vertical direction. 
     The transition detection means in such a circuit arrangement may be constructed so as to output a digital data word or a characteristic pulse as the characteristic information. In a circuit arrangement according to the invention in which the transition detection means is constructed so as to output a characteristic pulse as characteristic information, it has been found that it is advantageous when, additionally, the control information generating means, receiving an output characteristic pulse, includes a pulse stretching circuit, whereby control information is generated and output as a control pulse which has been stretched relative to a characteristic pulse received. This is advantageous notably with a view to realizing a particularly simple circuitry. 
     For a circuit arrangement according to the invention, it has also been found to be advantageous when, additionally, the filter means is formed by a recursive filter having a delay branch including a feedback factor adjusting stage as the controllable influencing means, a feedback factor being variable between the value “1” and the value “0” in said feedback factor adjusting stage, the pulse stretching circuit being connected to the feedback factor adjusting stage, and upon appearance of a stretched control pulse, the feedback factor being reduced or set to the value “0” for the duration of the stretched control pulse. Such an embodiment has proven to be particularly effective in practice in that the filter means is provided for noise suppression purposes. For a circuit arrangement according to the invention in which the transition detection means is constructed so as to output a characteristic pulse as characteristic information, it has also been found to be advantageous when, additionally, the control information generating means, receiving an output characteristic pulse, includes an input terminal for receiving the characteristic pulse, a direct channel connected to the input terminal for practically non-delayed propagation of the characteristic pulse received, and a delay channel connected to the input terminal and including further delay means, whereby the characteristic pulse received is delayed by the duration of at least one line, and combination means following the direct channel ( 80 ) and the delay channel, having a logic OR-function, and outputting control information in the form of a non-delayed characteristic pulse, and subsequently a delayed characteristic pulse. This is particularly advantageous in that in successive lines, it enables termination of the propagation of a comb-filtered component of a video signal, each time in the same line area which corresponds to the length of a vertical transition and hence to the duration of a characteristic pulse, at the same time, the propagation of this component of the video signal in non-filtered form being activated instead. 
     In order to solve the above problem, a video recorder of the kind set forth in the second paragraph according to the invention is characterized in that control information generating means is included in the connection means between the transition detection means and the influencing means, the control generating means receiving the characteristic information generated by the transition detection means, and generating, in dependence on the reception of characteristic information, control information which is applied to the influencing means so as to terminate the propagation of the comb-filtered component of the video signal, and activate the propagation of this component of the video signal in at least essentially non-filtered form for a period of time which is longer than is possible by means of the characteristic information. Thus, in a video recorder according to the invention, advantages are achieved which correspond to the advantages disclosed in the foregoing for a circuit arrangement according to the invention. 
     The advantageous further embodiments of a video recorder according to the invention offer advantages which correspond to the advantages previously disclosed for the advantageous embodiments of a circuit arrangement according to the invention. 
     The foregoing aspects and further aspects of the invention will become apparent from the two embodiments described hereinafter and will be illustrated with respect thereto. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The invention will be described in detail hereinafter on the basis of two embodiments which are shown in the drawings, however, without the invention being restricted thereto. In the drawings: 
     FIG. 1 shows, diagrammatically, a first embodiment of a video recorder and a circuit arrangement in the video recorder according to the invention, including control information generating means for generating control information for influencing means, the control information generating means being formed by a pulse stretching circuit; 
     FIGS. 2A,  2 B,  2 C and  2 D show signal waveforms occurring in the circuit arrangement of the video recorder shown in FIG. 1; and 
     FIG. 3 shows, in the same way as FIG. 1, a second embodiment of a video recorder and a circuit arrangement in the video recorder according the invention, including control information generating means for generating control information for influencing means, and including delay means having a delay of one line as well as combination means with a logic OR-function. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     FIG. 1 shows a video recorder  1 . The video recorder  1  includes two rotatably drivable magnetic heads  2  and  3  whereby a magnetic tape can be scanned in known manner along helical, adjacent tracks in order to play back color video signals recorded on the magnetic tape. A device  4  with rotatably drivable transformers as well as a head switching device (not shown) is connected to the magnetic heads  2  and  3  in known manner. 
     A circuit arrangement  5  for processing a playback color video signal is connected to the device  4 . To this end, the circuit arrangement  5  includes an input  6  which can receive a playback color video signal from the device  4 . A so-called head amplifier  7  is connected to the input  6 ; this amplifier amplifies a playback color video signal from the magnetic heads  2  and  3 . A playback color video signal can be applied from the head amplifier  7  to a brightness channel  8  and a color channel  9 . It is to be noted that a playback color video signal may include video signal segments which represent vertical transitions in a visually observable rendition on a display screen of a television apparatus or on a display device of another display apparatus. 
     The brightness channel  8  can process a brightness component, so a brightness signal Y, of a playback color video signal. Brightness signal processing means  10  is provided for this purpose. The brightness signal processing means  10  includes a highpass filter  11  which succeeds the head amplifier  7 , an FM demodulator  12  which succeeds the high-pass filter  11 , and a brightness signal noise suppression stage  13  which succeeds the FM demodulator  12 . It is to be noted that the brightness signal processing means  10  also includes, or may include, further signal processing stages which, however, are not described herein because they are not of essential importance in this context. The brightness signal noise suppression stage  13  can deliver a processed brightness signal Y which can be applied to a video signal processing device  15  via an electrically conductive connection  14  in the brightness channel  8 . 
     The video signal processing device  15  is connected, via an output of the circuit arrangement, to diagrammatically represented output means  16  of the video recorder  1 . The output means  16 , for example, formed by a so-called SCART connector, can apply a playback color video signal processed by the circuit arrangement  5  or the video recorder  1 , for example, to a television receiver. 
     A color component, so a color signal C, of a playback color video signal can be processed in the color channel  9 . The color channel  9  is provided with color signal processing means  17  for this purpose. The color signal processing means  17  includes a low-pass filter  18  which is connected to the head amplifier  7 . The low-pass filter  18  outputs a color signal C with a frequency around 627 kHz; this signal is applied to a mixing stage  19  connected to the low-pass filter  18 . Via an electrically conductive connection  20 , the mixing stage  19  can receive a mixing signal of a frequency of approximately 5.06 MHz from a mixing signal generator (not shown). The playback color signal C is retransposed in the mixing stage  19  so that the mixing stage  19  outputs a retransposed color signal C having a frequency around 4.43 MHz; this signal is applied to a bandpass filter  21  which succeeds the mixing stage  19 . A comb filter  22  is connected to the bandpass filter  21 . The comb filter  22  serves to eliminate crosstalk as has since long been known. In the present case, the comb filter  22  is succeeded by an amplifier stage  23  whose output supplies a retransposed color signal C which is substantially free from crosstalk. It is to be noted that the color signal processing means  17  additionally includes, or may include, further signal processing stages which, however, are not described herein because they are not relevant in the present context. 
     The color signal processing means  17  also includes filter means  24  which is connected to the amplifier stage  23 , and serves to achieve noise suppression in the color signal C of a playback color video signal. The filter means  24  includes an input  25  which can receive the color signal C output by the amplifier stage  23 . The filter means  24  can process the color component, i.e., the color signal C, of a playback color video signal according to the comb filter principle. 
     The filter means  24  includes a direct branch  26  which is simply formed by an electrically conductive connection  27  in the present case. The direct branch  26  propagates the processable color signal C of a playback color video signal without delay. The filter means  24  also includes a delay branch  28  whose construction will be described in detail hereinafter. Finally, the filter means  24  also includes combination means  29  which succeeds the direct branch  26  and the delay branch  28  and is formed, in the present embodiment, by a subtraction stage  29  for the subtraction of the signals applied thereto. The subtraction stage  29  outputs the comb-filtered color signal C of a playback color video signal via an output which is connected to an output  30  of the filter means  24 . The output  30  of the filter means  24  is connected to the video signal processing device  15  which thus forms a switching stage which succeeds the filter means  24  and serves to process the comb-filtered color signal C of a playback color video signal. 
     The delay branch  28  of the filter means  24  includes delay means  31  which is, in this case, formed by a charge-coupled device  31  (CCD). The input of the charge-coupled device  31  is connected to the output of the subtraction stage  29 . The charge-coupled device  31  is capable of delaying the signal applied thereto, i.e., the comb-filtered color signal C, by two lines (2 H). A bandpass filter  32  is connected to the charge-coupled device  31 . Connected to the bandpass filter  32  is a signal processing stage  33  which is capable of performing automatic gain control and automatic phase control. The output of the signal processing stage  33  is connected to a first input of a summing stage  34  whose second input is connected to the input  25  of the filter means  24 . The filter means  24 , in the present embodiment, is formed by a recursive filter whose delay branch  28  includes a feedback factor adjusting stage  35 . An input  36  of the feedback factor adjusting stage  35  is connected to an output of the summing stage  34 . The feedback factor adjusting stage  35  also includes a control input  37  which can receive a control signal as will be described in detail hereinafter. An output  38  of the feedback factor adjusting stage  35  is connected to an input of the subtraction stage  29 . A feedback factor can be switched between the value “1” and the value “0” in the feedback factor adjusting stage  35 , thus enabling adjustment of the comb filter effect of the filter means  24 , formed by a recursive filter, by appropriate adjustment of the relevant feedback factor. When the feedback factor is set or driven to the value “0”, the comb filter effect of the filter means  24  is completely switched off so that the propagation of the comb-filtered color signal C at the output  30  of the filter means  24  is terminated and, at the same time, the propagation of the color signal C of a playback color video signal in non-filtered form, via the output  30  of the filter means  24 , to the video signal processing device  15  is activated. The feedback factor adjusting stage  35  thus constitutes a controllable influencing means whereby the propagation of the comb-filtered color signal C of a playback color video signal to the video signal processing device  15  can be terminated and, at the same time, the propagation of this color signal C of a playback color video signal, in at least essentially non-filtered form, to the video signal processing device  15  can be activated. 
     The circuit arrangement  5  also includes transition detection means  39  whereby a vertical transition, represented by the brightness component, i.e., by the brightness signal Y, and also by the color component, i.e., the color signal C, can be detected and whereby, upon detection of such a transition, characteristic information can be generated and output via the output means  40  of the transition detection means  39 . The output means  40  is formed by an output terminal. The transition detection means  39  includes input means  41  which is formed by an input terminal and is connected to the electrically conductive connection  14  in the present embodiment. Via the input means  41 , the transition detection means  39  in the present embodiment can receive the brightness signal Y processed by the brightness signal processing means  10 . 
     The transition detection means  39  includes an amplifier  42  which is connected to the input means  41  and serves to amplify the brightness signal Y. The transition detection means  39  also includes a delay device  43  which is connected to the input means  41 , for delaying the brightness signal Y by the duration of one line (1 H), and for applying the delayed brightness signal Y H  to a controllable amplifier  44  for amplifying the delayed brightness signal Y H . The transition detection means  39  also includes a socalled non-correlation detector  45  which receives the amplified, non-delayed brightness signal Y via a first input  46  and, via a second input  47 , the amplified delayed brightness signal Y H . The non-correlation detector  45  determines whether the two brightness signals Y and Y H  applied thereto are correlated, i.e., whether they essentially correspond, or are not correlated, i.e., whether they deviate from one another by more than a given degree. 
     FIG. 2A shows a part of the brightness signal Y of a playback color video signal. The brightness signal first of all has an amplitude value which corresponds to the black level. Subsequently, a jump occurs in the brightness signal Y, i.e., to an amplitude value which corresponds to the white level. Thereafter, the brightness signal Y retains the amplitude value in conformity with the white level. Subsequently, a further jump occurs in the brightness signal Y, i.e., to the previously assumed amplitude value which corresponds to the black level. The described signal variation, of course, is given merely by way of example. 
     FIG. 2B shows the brightness signal Y H  which has been shifted in time by one line (1 H) with respect to the brightness signal Y H  of FIG. 2A by the delay device  43 . 
     When the above two brightness signals Y and Y H  are applied to the non-correlation detector  45 , the detector  45  outputs, via the output means  40  of the transition detection means  39 , characteristic information in the form of a characteristic pulse KI if the two applied brightness signals Y and Y H  clearly deviate from one another. FIG. 2C shows such characteristic pulses KI. 
     The output means  40  of the transition detection means  39  is connected to the influencing means, i.e., to the feedback factor adjusting stage  35 , via connection means  48 , so that in response to the output of characteristic information in the form of a characteristic pulse KI by the output means  40  of the transition detection means  39 , the feedback factor adjusting stage  35 , acting as influencing means, ensures termination of the propagation of the comb-filtered color signal C of the playback color video signal and activation of the propagation of this color signal C of the playback color video signal in at least essentially non-filtered form. 
     In the video recorder  1  or th e circuit arrangement  5  shown in FIG. 1, control information generating means  49  is advantageously inserted in the connection means  48  between the transition detection means  39  and the influencing means, formed by the feedback factor adjusting stage  35 , in such a manner that an input  50  of the control information generating means  49  is connected to the output means  40  of the transition detection means  39 , and an output  51  of the control information generating means  49  is connected to the control input  37  of the feedback factor adjusting stage  35 , constituting the influencing means. The control information generating means  49  receives the characteristic information generated by the transition detection means  39 . The control information generating means  49  generates, in dependence on the reception of such characteristic information, control information for application to the influencing means so as to terminate the propagation of the comb-filtered color signal C of the playback color video signal and activate the propagation of this color signal C of the playback color video signal in at least essentially non-filtered form, for a period of time which is longer than can be achieved by means of the characteristic information. 
     In the present embodiment, in which the transition detection means  39  is arranged to output a characteristic pulse KI as the characteristic information, the control information generating means  49  receiving a characteristic pulse, includes a pulse amplifier stage  52  and a pulse stretching circuit  53  which succeeds the pulse amplifier stage  52  and can generate control information in the form of a stretched control pulse SI, i.e., stretched relative to the characteristic pulse KI received, as characteristic information which can be output via the output  51  of the control information generating means  49 . FIG. 2D shows such control pulses SI. 
     In the video recorder  1  or the circuit arrangement  5  of FIG. 1, the pulse stretching circuit  53  is connected to the feedback factor adjusting stage  35  of the filter means  24 , in the form of a recursive filter. When such a stretched control pulse SI is applied from the pulse stretching circuit  53  to the control input  37  of the feedback factor adjusting stage  35 , the feedback factor is set to the value “0” in the feedback adjusting stage  35  for the duration of the stretched control pulse SI. Consequently, the comb filter effect is deactivated so that, instead of the comb-filtered color signal C, the non-filtered color signal C is output via the output  30  of the filter means  24  so as to be applied to the video signal processing device  15 . 
     The pulse stretching circuit  53  of the present embodiment is constructed in such a manner that a stretched control pulse SI covers the duration of essentially five lines in total. It is to be noted that, evidently, a different duration of the stretched control pulse SI is also feasible, for example, a duration corresponding to only four or three lines, but also to six or seven lines. 
     Using only simple means in the described video recorder  1 , or its circuit arrangement  5 , it is advantageously achieved that the feedback factor adjusting stage  35  ensures, for a period of time lasting several lines, the influencing of the termination of the propagation of the comb-filtered color signal C of a playback color video signal and of the activation instead of the propagation of the color signal C of the playback color video signal in non-filtered form, so that a color signal C of a color video signal, delayed by the filter means  24  by the duration of more than one line (1 H), does not have a disturbing effect on the visually observable rendition of a transition extending in the vertical direction. 
     For the described embodiment, it was assumed that each of two transitions, represented by the two jumps in the brightness signal Y and extending in the vertical direction in a visually observable rendition, extends practically across the entire line length. Evidently, this is to be understood merely as an example, because such a transition may also extend over only a part of the overall line length as is actually often the case in practice. 
     For the embodiment of the video recorder  1 , or its circuit arrangement  5 , as described with reference to FIG. 1, it was assumed that the feedback factor is changed or set to the value “0” in response to the appearance of the control information SI at the control input  37  of the feedback factor adjusting stage  35 . It is to be noted that the feedback factor need not necessarily be reduced to the value “0” and that changing the feedback factor to a value slightly higher than the value “0” is also feasible. 
     FIG. 3 shows a second embodiment of a video recorder  1  and a circuit arrangement  5  according to the invention. Hereinafter, only those components of the video recorder  1  and its circuit arrangement  5  will be described in respect of which the video recorder  1  or its circuit arrangement  5  deviates essentially from the first embodiment of the video recorder  1  and the circuit arrangement  5  shown in FIG.  1 . 
     FIG. 3 shows the comb filter  22  in the color channel  9  in greater detail. The comb filter  22  forms filter means  22  whereby the color component, so the color signal C, of a playback color video signal can be processed in conformity with the comb filter principle. The comb filter  22  includes an input  55  which is connected to the bandpass filter  21 , and an output  56  wherefrom the comb-filtered color signal C can be derived. 
     The comb filter  22  includes a direct branch  57  which is formed essentially by an electrically conductive connection  58  which connects the input  55  of the comb filter  22  to a first input  59  of a summing stage  60 . The color signal C to be processed can be applied to the summing stage  60  practically without delay via the direct branch. 
     Furthermore, the comb filter  22  includes a delay branch  61 . The delay branch  61  includes a first delay stage  62  which is connected to the input  55  of the comb filter  22 , and a second delay stage  63  which is connected to the first delay stage  62 . The two delay stages  62  and  63  constitute delay means of the delay branch  61 . The delay branch  61  also includes a switching stage  64 , a first input  65  of which is connected to the output of the first delay stage  62 , while a second input  66  is connected to the output of the second delay stage  63 . An output  67  of the switching stage  64  is connected to a second input  68  of the summing stage  60 . The output  67  of the switching stage  64  is connected to the first input  65  of the switching stage  64  in the case of playback of an NTSC color video signal. In the case of playback of a PAL color video signal, the output  67  of the switching stage  64  is connected to the second input  66  of the switching stage  64 . For the control of the switching stage  64 , the circuit arrangement  5  is provided with control means  69  whereby a PAL/NTSC switching signal P/N can be generated so as to be applied to a control input  70  of the switching stage  64 . 
     The delay branch  61  thus delays an applied color signal C by one line (1 H) overall in the case of playback of an NTSC color video signal, and by two lines (2 H) in the case of playback of a PAL color video signal. 
     The video recorder  1  and the circuit arrangement  5  shown in FIG. 3 also include controllable influencing means  71  whereby propagation of the comb-filtered color signal C of a play-back color video signal from the output  56  of the comb filter  22  to the switching stage which succeeds the comb filter  22 , and is, in this case, formed by the amplifier stage  23 , can be terminated and, at the same time, the propagation of the color signal C of a playback color video signal in non-filtered form to the amplifier stage  23  can be activated. In the present case, the controllable influencing means  71  is formed by a further switching stage  71 . The further switching stage  71  includes a first input  72  and a second input  73  and a control input  74  as well as an output  75 . The first input  72  is connected, via an electrically conductive connection  76 , directly to the output of the bandpass filter  21 . The second input  73  is connected to the output  56  of the comb filter  22 . The output  75  is connected to the amplifier stage  23 . The means connected to the control input  74  will be described in detail hereinafter. 
     The output means  40  of the transition detection means  39  in the video recorder  1  and the circuit arrangement  5  of FIG. 3, is again connected to the controllable influencing means  71  by means of connection means  54 . 
     In the connection means  54  between the transition detection means  39  and the influencing means  71  in the video recorder  1  and the circuit arrangement  5  of FIG. 3, there is inserted control information generating means  77  which includes an input terminal  78  and an output terminal  79 . The input terminal  78  is connected to the output means  40  of the transition detection means  39 . The output terminal  79  of the control information generating means  77  is connected to the control input  74  of the influencing means  71 , so the further switching stage  71 . 
     The control information generating means  77  includes a direct channel  80  which is connected to the input terminal  78  and consists of an electrically conductive connection  81 , and also include a delay channel  82  which is connected to the input terminal  78  and includes further delay means, i.e., a delay device  83 . A characteristic pulse KI received at the input terminal  78  can be propagated without delay via the direct channel  80 , so the connection  81 . The delay device  83  can delay a characteristic pulse K 1  received at the input terminal  78  by the duration of one line (1 H) and output it as the delayed characteristic pulse KI H . 
     The delay channel  82  also includes a switching stage  84  which is connected to the delay device  83  and comprises an input  85 , a control input  86  as well as an output  87 . The control input  86  is connected to the control means  69  so that the control input  86  of the switching stage  84  also receives the PAL/NTSC switching signal P/N. The PAL/NTSC switching signal P/N ensures that the input  85  of the switching stage  84  is connected to the output  87  in the case of playback of a PAL color video signal, while, in the case of playback of an NTSC color video signal, the connection between the input  85  and the output  87  is interrupted. 
     The control information generating means  77  also includes combination means  88  which succeeds the direct channel  80  and the delay channel  82 , and has a logic OR-function. One input of the combination means  88  is connected to the electrically conductive connection  81  of the direct channel  80 , while the other input of the combination means  88  is connected to the output  87  of the switching stage  84  of the delay channel  82 . The output of the combination means  88 , at the same time, constitutes the output terminal  79  of the control information generating means  77  which is connected to the control input  74  of the further switching stage  71  provided as the controllable influencing means. 
     The combination means  88 , having a logic OR-function, outputs control information in the form of a non-delayed characteristic pulse KI as well as a delayed characteristic pulse KI H . 
     When a characteristic pulse KI or a delayed characteristic pulse KI H  appears at the control input  74  of the further switching stage  71 , the first input  72  of the further switching stage  71  is connected to the output  75  thereof, thus ensuring that propagation of the comb-filtered color signal C of a playback color video signal to the amplifier stage  23  is terminated, and, at the same time, propagation of the color signal C in non-filtered form to the amplifier stage  23  is activated. 
     Using very simple means, it is thus advantageously achieved that termination of the propagation of a comb-filtered color signal C and simultaneous activation instead of the propagation of the non-filtered color signal C can be realized within successive lines, each time within the same line region which corresponds to the length of a transition extending in the vertical direction and hence to the duration of a characteristic pulse KI and a delayed characteristic pulse KI H . It is thus also achieved that the system-inherent delay time intervals of different length, occurring in the brightness channel  8  and in the color channel  9  in a PAL system, i.e., 1 H for the brightness signal Y and 2 H for the color signal C, are compensated. It is to be noted that instead of the compensation of the different delay time intervals of 1 H and 2 H by additionally delaying the characteristic pulse KI by means of the delay device  83 , another compensation of such different delay time intervals of 1 H and 2 H can also take place, i.e., delaying the brightness signal Y occurring ahead of the transition detection means  39 , additionally to the 1 H delay executed before in the brightness channel  8 , by the duration of one line (1 H) and applying this delayed brightness signal to the transition detection means  39 .