Video record

© Start of patent term: 1977 11 15 Longest possible duration:

© Issued on: 1978 07 10 © inventor:

© Dependency: '© Pamphlets considered to delineate the state of the art:

No.344263

The invention relates to a method for producing a video recording on a disc-shaped record carrier, in which are located in surrounding tracks video information, which are provided for reproducing by means of a television display device, which video information is divided into line segments and in the line segments Teilbildabsehnitte, the Video information of two partial image sections, which are provided in one or more rounds of a track, during a time interval corresponding to the reproduction of a complete image, results in a line-shifted image in the display device, which recording medium is suitable for reproducing a motion picture containing television picture in the form of a series of more than two successive fields and also for the repeated reproduction of two successive fields for obtaining a television still picture.

It should be noted that plate-shaped or disk-shaped record carriers carrying video information are often called video disks.

The invention further relates to a circuit arrangement for imposing the method according to the invention and to a plate-shaped recording medium with a video recording produced by the method according to the invention or using the circuit arrangement according to the invention.

In Philips Technical Review, 1973, No. 7, pages 190 to 192 inclusive, a video playback system is described with a disc-shaped or disk-shaped record carrier. The video information in this system is encoded on the record carrier in the form of a succession of variable-length, variable-frequency pits. The circular or spiral track with the pattern of pits is scanned by a light spot, and the reflected light is converted into an electrical signal via a photodiode. From this electrical signal a video signal is derived by means of a decoding, which is suitable for reproduction with a standard television display device.

The Lieftfleekabtastung offers the ability to receive a television still picture on display by a repeated sampling of a once or several times around running track with information contained therein, which belongs to a television picture formed from two line-shifted fields. This possibility exists, for example, with a magnetic information track on the video disc and with magnetic scanning of the same. On the other hand, this possibility is absent in a system having a video disk with an information track in a spiral groove and a mechanical groove scan of the same. Namely, it can not jump back quickly enough from the end of the second field to the beginning of the first field, which is necessary for the repeated reproduction of two fields forming the television picture.

In a video disc reproducing system capable of still picture reproduction obtained by repeatedly reproducing the information of two fields, this reproduction often results in a flicker phenomenon which does not occur in a continuous continuous reproduction. The cause of such flicker is the presence of a motion at a point in the scene to be shot between the taking eye in one field and that in the other field.

The repeated reproduction of the two partial images with the information shift between the two partial images caused therein by the movement in the scene leads to the mentioned flicker phenomenon, which occurs with the image frequency.

It is an object of the present invention to obtain a television still picture formed by repeatedly reproducing two line-separated fields with video information without causing a troublesome flicker caused by the movement in the recorded scene. This aim is to be achieved under the condition that the good picture quality is not appreciably affected by the normally continuous reproduction of the information from the video disc.

The inventive method of the initially mentioned kind is characterized in that the recorded image signals are combined in groups of two sub-images and recorded from these field signals two to be recorded on the carrier, eg by delayed by at least one field duration and optionally by at least one line duration, differently corrected signals are formed, wherein on a moving object edge in the image belonging to a line signals of the first field and the signals of the intermediate to be reproduced second field of a group have a corresponding course . so that in the reproduction of a still image flicker by raster frequency jumping of the object edge is avoided or at least substantially reduced, and that the signals thus obtained are recorded on the carrier.

An advantageous embodiment of the method according to the invention is further characterized in that when recording the video information on the recording medium an image sync signal for determining the position of the beginning of the different groups, each corresponding to two associated sub-images, is used.

Nr.344263

The circuit arrangement according to the invention provided for carrying out a method according to the invention is characterized in that the circuit arrangement with at least one delay arrangement whose delay time corresponds to almost one field duration is arranged between an input terminal and an output terminal and with at least two superimposition stages, is provided with at least one Um5 switching arrangement with two input terminals and an output terminal and with a switching signal generator for supplying the switching circuit per field switching switching signal, the output terminal of the switching arrangement with a first output terminal of the circuit arrangement and the input terminal of the delay arrangement with an input terminal of the circuit arrangement coupled, and the superposition stages are arranged for signal combining between terminals of the circuit 10 arrangement, the delay arrangement and the switching arrangement.

An advantageous development of the circuit arrangement according to the invention is characterized in that the circuit arrangement is provided with a second output terminal, which is connected to provide the Bildsynchronsignals via a frequency divider stage with a division factor two with an output of the switching signal generator.

The record carrier according to the invention of the type mentioned above, which record carriers are also called video disks, is characterized in that the video information present in the circulating tracks on the record carrier is recorded in different groups from two respective sub-picture sections, wherein in each group the information of the first sub-picture is only slightly differs from that of the second field, and there are groups, in which the Video20 information differs substantially from that of the following group.

An advantageous embodiment of the record carrier according to the invention is characterized in that in the circulating on the record carrier present on the record carrier corresponding to a television standard horizontal and vertical synchronous information a the different groups of two associated sub-picture sections defining image synchronizing information is recorded25.

The invention will now be further described by way of examples shown in the drawings. In the drawings, FIG. 1 is a diagram for explaining the flicker phenomenon to be corrected in a repeated reproduction of the information of two partial image portions of a video disc, FIG. 2 3 shows a circuit arrangement for carrying out the method according to the invention, FIGS. 4 and 5 show some timing diagrams associated with the arrangement according to FIG. 4, FIGS. 6 to 10 show further circuit arrangements according to the invention, FIG 7 shows some timing diagrams of output signals which occur in the circuit arrangements according to FIGS. 7 to 10, and FIGS. 12 and 13 show circuit arrangements for carrying out the method according to the invention in color television.

In Fig. La, a video disk -1-- is shown in view. The video disk - 1- is provided with a central hole -2- for a spindle of a turntable. On this video disk -1-, video information is recorded in spiral-shaped tracks from the outer edge to the inner circle -3, of which three semicircular track sections are labeled -4, 5 and 6. Due to the spiral track course, the semicircular track sections -4, 5 and 6 do not ideally follow the circular shape, but are only approximately circular. In the track sections -4, 5, 6, etc., the video information corresponding to a television field picture is recorded. The encoded video information may be formed, for example, in the form of a pattern of pits, which pattern is scanned by a light spot, or in the form of a magnetic pattern that can be read out by means of a magnetic scan. Apart from a mechanical scanning of an information groove as a track, which is not considered here, the way in which information has been recorded is of subordinate importance.

In the usual way in television, the video and synchronous information occurs in line-shifted television sub-pictures composed of television lines, with two line-separated sub-pictures always forming one frame. In track section -4-, a first line is denoted by -7- and a second line by -8-. The track section -4- ends with a -9- designated half-line. The track section 50-5-- starts with the information of a half-line designated -10- and ends with a whole line designated -11-. The information in the track section -6- is recorded in the same manner as in the track section -4-. In the usual manner in television, half-lines -7, 8, 11 and 9, 10 also contain field sync information.

Starting from the semicircular track section --5--, a line-shifted television picture is formed on the one hand with the preceding sub-picture of the track section -4- and on the other with the following sub-picture of the track section -6-. The same applies to the sub-picture of the track section -4- with the preceding and the subsequent sub-picture of the track section -5- or for the track section -6- with the preceding sub-picture of the track section -5- and the following

Field. Consequently, two successive fields always form a line-shifted image.

Nr.344263

In Fig. Lb is a view of a line-shifted image is displayed during playback. With --X- is a reproduced television line referred to, the information of which, for example, from the track section -4- on the video disk -1-comes from Fig. La. A Y-line is a reproduced television line whose information originates, for example, from the track section ~ 5 ~ on the video disk ~ 1 from Fig. La. With -Z- in Fig.lb a line in the vertical scanning direction is indicated.

In Fig.lb also a rectangle delimited with full lines is shown, which belongs to the part of the image embodied by the information of the track section -4- and further a rectangle delimited by dashed lines, to the by the information of the track section -5- (Fig .la) embodied part picture belongs. The two fields thus contain signals of a rectangle which has moved during the recording, so that it assumes a different, shifted position in the two fields. If now both fields are reproduced repeatedly, then the rectangular image jumps back and forth and causes a disturbing flicker. Herein it is obtained by the repeated reproduction of the information of the track sections -4 and 5- characterized in that the information sample at the end of the line -11- of the track section -5- jumps to the beginning of the line -7- of the track section --4- , If an ideal circular shape of the track sections -4 and 5 were provided instead of the spiral track of the information tracks, this jump operation would not be necessary for obtaining a still picture, but it would have to be continuously jumped from one track section to the next with continuous reproduction of a television picture. In order to jump quickly without affecting the reproduced image, as shown in Fig.la, the start and end points of the recording track must be close to each other. So it is at least an approximately complete circulation of the track necessary. Of course, more or less complete laps of the lane may be provided for a track portion representing an image.

As Fig.lb shows, results in the reproduction of a rectangular moving object between the one field (television line -X-) and the other field (TV line -Y-) a shift. For this purpose, the information of the lines -X and Y- is plotted in FIG. 1c as a function of time.

In Fig.ld the information is shown, as this occurs at the registered in Fig.lb line ~ Z-. The instantaneous information at the location of the line -Z-, which appears as a pattern of information of the television lines in one and in the other field, is denoted by a dot -ZI- or a cross -Z2-. Assuming that the line ~X- of Fig.lb belongs to the information of the track section -4- in Fig.la, it follows that information patterns originating from the track section -4- are represented by the points -ZI- from Fig.ld are. The information at the crosses -Z2- of Fig.ld then belongs to the information patterns derived from the track section -5- of Fig. 1a.

The shift, which is illustrated in Fig.lb by hatching, gives a flicker with the frame rate (25 Hz), since at the location of the hatching one field, for example, the information black and the other field contains the information white.

FIG. 2 shows a number of time diagrams that are comparable to those in FIG. The information patterns of one field are indicated in Fig. 2 by full and the other by dashed lines. In Fig. 2a, a transition in the vertical scanning direction (line -Z- in Fig.lb) is shown with a signal Al, which has undergone no shift during a field duration, ie in the image when recording a movement has occurred. By ΐ_η_θ, in-4> in-2> * n> * n + 2 ^{un <}^ * n + 4 ^sintAn information pattern denotes how they occur in a field, where n is an odd integer. In the (preceding or following) sub-image, the interlacing process causes the information patterns in -5> in-3> nl>²n + l> ^ n + 3 ^unc^ ^ n + 5 ^auL

In Fig. 2a, AC1 represents a signal as occurs in vertical vertical aperture correction commonly used in television. The aperture correction is used to improve the image quality in the reproduction, whereby a correction signal (AC1) is added to the signal transitions with a slight slope, the slope becomes steeper, and a larger signal difference is obtained between the initial and final values. The derivation of the vertical aperture correction signal AC1 will be described in more detail below. The signal AC1 is multiplied by a factor p added to the signal Al, which then yields an aperture corrected signal F1.

In Fig. 2b, a signal A2 is shown, wherein the information pattern shown in solid lines (i_netc.) correspond to those in the signal Al of Fig. 2a, while the information pattern shown by dashed lines are shifted to the right in the figure. The size of the information i_n_3 in the signal A1 of FIG. 2a now appears in the information i_n+ i from Fig.2b on, ie the information is shifted in its field by two lines down (Fig.lb). This shift is presumed to occur within a very short time immediately after the local scan in the previous field occurred at the time the scene was taken. There is only one information shift and the (shifted) size is not affected. In practice, a shift will not occur immediately after a local scan and will take some time so that not only does an information shift occur

No. 344263 also a flattening of the information size. In order to explain the invention as simply as possible, this effect has not been taken into account.

Further, it has been assumed that there is no open space in the recording between the lines in each television field, so that the effective light integration time when taking a field duration is equal. If there had been an open space, which corresponds to an ideal interlacing between two successive fields, then the effective light integration time would have corresponded to an image duration of the duration of two fields.

In Fig. 2b, a vertical aperture correction signal AC2 is plotted, which can be derived from the signal AC1 of Fig. 2a in that the information shown by dashed lines are also shifted by two lines in its own field. In Fig. 2b, a signal F2 indicates a signal corrected for the factor p = vertical-aperture.

A comparison of the signal Fl of Fig. 2a with the signal F2 of Fig. 2b shows that when the signal F2 is reproduced with the shift therein, a flicker phenomenon will occur. From the signals A2 and F2, it can be seen that the flicker phenomenon has been emphasized by the vertical aperture correction.

In order to avoid the flicker phenomenon during playback as explained with reference to the signal F2 from FIG. 2b, it would be possible to repeat the information of one field in the other field duration, resulting in a signal S1 according to FIG. 2c. The signal A2 of FIG. 2a information shown in full lines is repeated via a delay arrangement whose delay time corresponds to one field duration plus half a line duration, in the following partial image shown dashed instead of the shifted information. The signal of one field is then reproduced twice; the signal of the other field is not used. At this time, a vertical aperture correction signal designated by SCI occurs, giving a signal S12 for reproduction.

The signal S12 of Fig. 2c gives an improvement in flicker appearance as compared with the signal F2 of Fig. 3b in the reproduction, but as significant drawbacks there is a halftone reduction in the vertical direction and the appearance of a vertical pattern (with dashes in the horizontal direction), which is caused by the staircase character of the signal S12.

With a circuit arrangement according to the invention, as illustrated in FIG. 3 a, a flicker-compensated image can be obtained during reproduction without the introduction of disturbing phenomena; such a circuit arrangement according to the invention is suitable for providing the information for the tracks from a video disc. For this purpose, some signals A, B, C, D, E, AC / E and F in the form of instantaneous information i are given in FIG. 3b to explain the signal processing.

In Fig. 3a -20- an arrangement is designated, with which the information tracks with video and synchronous information in coded form on a video disc or disc are aufgezeiehn. The information tracks can be formed, for example, in a manner already mentioned as a depression pattern or as a magnetic pattern. The formation of the arrangement -20- is in itself less relevant to the invention, so that it is disregarded in the following discussions. With -21- is designated a video signal source, which may be, for example, a scene-capturing television camera or a video disc, from which the information is taken. The signal source -21- is connected to outputs of a signal generator -22- which outputs signals Syi and Sjji, supplying signals Sy and Sjj while supplying external synchronizing signals. The signals Sy and Sjj are, for example, the vertical (V) and horizontal (V) prescribed according to a television standard. H) synchronizing and blanking signals, which, if necessary, are used to control the signal source -21- and occur, for example (unchanged), in the camera video signal A emitted by the video signal source -21-. The structure of the signals Sy and Sjj is not relevant to the invention, so this is disregarded.

The video signal output of the source -21- is connected to an input terminal -23- of the arrangement according to the invention according to Fig. 3a, having a first output terminal -24j- for outputting a modified video signal F and having a second output terminal -24 £ - for outputting an image Sync signal which outputs are connected to inputs of the array -20-. The input terminal -23- is connected to a series arrangement of two delay circuits -25 and 26- each having a signal delay time corresponding to a line duration Tjj. Via an attenuation stage -27- (generally denoted by a) with a factor of -g-, the input terminal -23- with the signal A is connected to a first input terminal of an adder stage -28-. The output terminal of the delay arrangement -26- with the signal C is connected via a damping stage -29- with a factor at a second input terminal of the stage -28-. A third input terminal of stage -28- is connected to the output terminal of a switching arrangement -30- which is provided with two input terminals. To control the switching arrangement -30- this is to a Aus6

No.344263 gear of a switching signal generator -31- is supplied with the signal Sy, whereby during the one field duration the one input terminal of the device -30- and during the other field duration the other input terminal is connected to the output terminal. The individual sub-image sections are denoted by index numbers N, where N = 1, 2, 3, ..., etc. To emphasize the switching operation taking place according to the partial image sections and the switching position of the Umsehaltanordnung

N N + l -30-, the input terminals are labeled i and i, with the proviso that

N N + 2 N + 4 N + 1 N + 3 N + 5 i = i = i etc. and i = i = i, etc.

N

The input terminal i of the switching device -30- is connected to the signal B leading connection point of the delay devices -25 and 26-. Parallel to the delay arrangement-26- a superposition stage -32- is provided. The output terminal of stage -32-, which carries the signal D,

I ^TH \ is connected to a delay device -33-, which has a delay time IT_v - -7- | has, corresponding to nearly one field duration (Ty). The delay time ('V -?)' Corresponds to one

V 2

Sub-picture duration Ty less than a half line duration Th, whereby, when current information of one line in a field, ie from a certain position on the line, is applied to the output terminal of the device -33-, the corresponding position of the subjacent line of the preceding field N + l corresponding information occurs. In general, it follows that upon supply of information i at the

Output terminal of the device -33- the information i occurs, where with N = 1, 2, 3, 4 ... the HtZ

Teilbildabsehnitte and with n = 1, 3, 5, ... the lines are designated, up to and including the odd number of lines, according to the Eernsehnorm comprises an image formed from two line-shifted fields.

Via an attenuation stage -34- with a factor i, the output terminal of the delay arrangement 33- is connected to the terminal i of the Umsehaltanordnung -30-, then the signal E occurs. The connection point between the delay circuits - 25 and 26-, on which the signal B lies, is connected to an input terminal of a superposition stage -35- whose output terminal with the signal F is connected to the output terminal -24 ^ - of the arrangement Stage -35- is connected to an output terminal of a switching arrangement -36- with two input terminals N N + li and i, which via a damping stage -37 bzw.38- with a factor p or q are connected to the output terminal of the stage -28-, which carries the signal AC / E. The switching arrangement 36- as well as the switching arrangement -30- is controlled from the switching signal generator -31- and switches in a corresponding manner.

To obtain an image sync signal at the output terminal 242, it is connected to the switching signal generator -31- via a frequency divider stage -39- having a frequency divider with a divide ratio f = 2.

For convenience, the switch assemblies -30 and 36- are drawn with mechanical shift arms, but in practice they will be implemented electronically. Furthermore, the attenuation stages -27 and 29- can be included in the superposition stage -28-, which also applies to the stages -34 and 32- and to be described further stages. Instead of the switching arrangement -36- being arranged behind the steps -37 and 38-, it could also be arranged in front of them.

The arrangement according to FIG. 3 a is provided with a vertical aperture correction circuit which is formed by the components labeled -25, 26, 27, 28, 29, 35 and 37. The vertical movement correction circuit (-25 to 29, 35, 37-) is effective in a known manner with the switching position of the switching circuits -30 and 36 shown in FIG. 3a. For explanation, in Fig. 3b shows some instantaneous information i with the field numbering N (= 1, 2, 3, ...) and the part numbering n (= 1, 3, 5, ...). At the point where information for explaining the invention is not relevant, three points are set, which will also be the case in the following drawings.

N

When a video signal A = i is supplied, after the delay arrangement -25 or 26, respectively, the Inn + 2 formation of only one line or two lines earlier occurs in the same field, which corresponds to the given nN N

Numbering by a number 2 deviates, so B = i and C = i. It follows that the superposition stage Ω H * ~ 2

Nr.344263

-28-- a correction signal

AC / E .N 1 /. N, N \^Tn 2 \ ¹ n-2 \ i + 2), which after the superposition stage -35- the vertical aperture corrected signal .N n

NN \ n-2 n + 2 / yields. This signal is obtained with the arrangement according to FIG. 3a as a signal i, which signal can be regarded as a partial image, to be considered as a first partial image, of different groups of respectively two associated image-resultant partial images. In the second sub-picture of the groups werN + l connected via the switching arrangements -30 and 36- the terminals i through. When doing the video signal source -21- the signal

N + li

n + 3, the signals appear behind the delay circuits -25 and 26-

N + 1, 1 or C n + 1

N + li

n-1 up. Compared with the signal .N + l n + l which is supplied to the delay arrangement -3-, the output terminal carries a signal component which belongs to the preceding field N and lies in this field by one line lower in the image, ie the line with the number n + 2nd It follows that the signal of Fig. 3b is the signal (i^N + i^N ) \ n + 2 n / results. From the signals A, C and E, the stage -28- becomes a correction signal

AC / E (.N .N - 1 +1 \ n + 2 n / .N + l .N + l \

- l + i \ n-1 n + 3 / made, and thus ensures that the stage -35- a signal F with .N + l ' ¹n + l

N + l ^Xn + 1 / N \\ i + 2

N \ ^{+ 1} n / / N + l N + l \ n-1 ⁺ ^ + 3 outputs according to Fig. 3b.

The mode of operation of the arrangement according to FIG. 3 a will now be explained on the basis of the signals illustrated in FIG. 4. 4a and 4b apply to the cases described in FIGS. 2a and 2b, the signals A1 and A2 from FIG. 2 corresponding to the signals A1 and A2 from FIG. It can be seen that the correction signal AC / El according to FIG. 4a differs only slightly from the correction signal AC1 according to FIG. 2a; as a difference one obtains that the correction signal for the second field (N + 1) has been reduced by half in each group. The korδ

Nr, 344263, signal F is in Fig. 4a for p = -, q = 0 &

designated Fll, for

1 p = -, q = - with F12 and Z Δ for p = q = 1 with F13. It follows that in the given example, the signal Fl of Fig. 2a to the Si2

However, the Kbrrektursignal AC / E2 of Figure 4b differs greatly from the signal AC2 of FIG. 2b. For p = or 1, the corrected signals F21, F22 and F23 are plotted in FIG. 4b. A comparison of signal F13 of Fig. 4a corresponds to that which means that in the signal Al, ie in the absence of motion, the image quality is not affected by the effect of the arrangement of Fig. 3a.

2

2 of the signal F2 of Fig. 2b, which gives a distracting flicker phenomenon in reproduction, with the signal F23 of Fig. 4b clearly shows that the signal F23 is no flicker during reproduction, the transition in the information patterns being gradual. The extent of the correction may also be chosen as desired by making the factors p and q of the stages -37 and 38-adjustable.

It can be seen that a flicker-free reproduction of a television still picture can be obtained by dividing the video information serially offered one after the other from the video signal source --21-- into different groups of two respective sub-pictures (N, N + 1) and a signal combination before recording on a video disk -1- (Figure 1a) with an arrangement -20- (Figure 3a). The image sync signal occurring at the output terminal -24 £ - ensures that for a particular choice of groups, for example, the track sections -4 and 5- of the video plate -1- of Figure la correspond to a group of two fields or the track sections 5 and 6 correspond to such a group, the further group formation of the following sub-images continues to take place in a corresponding manner. In other words: the picture sync signal at the terminalⁱⁿ Fig. 3a corresponds to a character on the video disk -1- of Fig.la which is effective in reproducing a still picture as the beginning character thereof. This initial character on the video disc -1- can be realized in various forms, for example in one of the three types listed below.

a) By attaching a marker, for example, on the outer edge of the video disk -1-, whereby depending on the location of this character, the track sections -4 and 5 or 5 and 6 or other corresponding track sections give the information for an image.

Characterized in that the image synchronizing information that occurs after the standards in the first lines of the sub-images, is changed after every two sub-images, this change is used as image Synehroninformation and is detected.

By specifying that the images should always begin with a particular one of the two types of sub-images, for example those sub-images that begin with a whole line of information (line 7 of the track section -4- of the video disc -1- of Fig. La) or with those Partial images starting with half an information line (line 10 of track section -5-). A display device for the video disk -1- is then according to this definition in such a way that when the reproduction of a still picture is required, for example in the course of a continuous playback, not just the next field and the subsequent field for the still picture playback are selected, but that is waited until the agreed to be considered as the first field of a group field to be detected.

From Fig. 4, in particular Fig. 4b with the signal F23, it can be seen that a displacement of the contents of the picked-up image in the image scanning direction no longer causes flicker phenomena.

That the arrangement of Fig. 3a is also effective for shifts in the line scanning direction will now be explained with reference to Fig. 5. In Fig. 5a, a signal transition in the line scanning direction for the lines NNN + 1N + 1 is shown

Information i and i shown in a field and for the line information i _ and i in n n + 2 n + l n + 3 and q = 0,

b)

c) the following drawing. In the reproduction shown in Fig. 5b, the line information i

N + l

_ .. _ N + 1 N + 1

i. etc., at the same place, while the line information i ", i" and i ", etc., at a vern-2 n + l n + 3 n-1

Resolved point occur, which is also shown in Fig. Lc.

From the signals shown in Fig. 3b it is apparent that the signal AC / E at the first field (N) is equal to zero, which for the signal F is the value

Ν 'N l = i η n. For the second partial image (N + 1) it holds that (N N + li - i n n + l corresponds to which signal is plotted in FIG

Nr.344263

Signal F applies:

N + l ' ¹n + l

N + l / N l + q | l n + l \ n .N + l \^Xn + 1}

Ν 'N + l'

In Fig. 5c, the signals i and i fiirq = 0, n n + 1 and 1 are plotted. It turns out that for q = 1 an ideal correction is obtained and that for q =

- Compared to q = 0 already results in a significant improvement.

FIG. 6 a shows a second embodiment of an arrangement according to the invention, with some instantaneous information i being given in FIG. 6 b to explain the mode of operation. The arrangement of FIG. 6a differs from that according to FIG. 3a with respect to the location at which the switching arrangement is provided, and it is the switching arrangement therefore in FIG. The output terminal of the switching circuit -30 '- is connected to an input terminal of the superimposing stage -35-, and it is the connection point in the series arrangement of the two delay arrangements -25 and 26- directly to an input terminal of Overlay level -28- attached. The interchanging of the terminals results in that the superposition stage -28- provides a normal vertical aperture correction signal ABC in each field, while for the second field (N + l ') not the own video signal but a combination of the first one Partial image, u.zw. - i + i is corrected. If Si2 \ n + 2 n /

The result is indicated in FIG. 6b. It follows that for q = 1 the information i of Sinti_χ gnals F from Fig. 6b of Fig. 3b corresponds. It follows that the signal F23 from FIG. 4b with p = - and q = 1 also applies to the arrangement according to FIG. 6a.

In the manner described for a shift in the line scanning device in FIG. 5, for the signal F from FIG. 6b follows:

I

i and n

N + l ' ^Xn + 1 / NN - i + i \ n + 2 n so that regardless of the factor q an ideal correction occurs.

In the arrangements of Figs. 7, 8, 9 and 10, there are no vertical aperture correction circuits. However, these circuits, as well as horizontal aperture correction circuits, may be provided between, for example, the output terminal 24χ- carrying the signal F and the arrangement -20- for producing a video disc. As far as is possible and expedient, in the arrangements according to FIGS. 8, 9 and 10 use the same reference numerals as in the arrangements of FIG. 3 and 6; this applies to components -20 to 24 and 31 and 39-.

In the arrangement of Fig. 7a, the input terminal -23- is connected to a series arrangement of three delay arrangements -40, 41 and 42-, the arrangements -40 and 42- having a delay time I Ty -j which is close to one field duration Ty and the arrangement-41- has a delay time corresponding to a line duration Th. The delay orders -40 and 41- / T_H\ have a total delay time I Ty ⁺~ 2 ~ li which also corresponds almost to the field duration Ty. This delay time could also be obtained by a single delay arrangement. The input terminal -23- with a signal A is connected through an attenuation stage -43- with a factor of one

Input terminal of a superposition stage -44- connected to a second input terminal via an attenuation stage -45- with a factor with the connection point of the arrangements -41 and

42-, on which the signal B is connected. The output terminal of the stage -45- is further at an input terminal of a superposition stage -46-, via a damping stage -47- with a factor of 1

- Is at the output terminal of the arrangement -42-, which leads a signal C. The output terminal of u

Stage -44- with a signal D and the output terminal of stage -46- with a signal E are connected to N N + l of an input terminal i and i, respectively, of a switching arrangement -48- whose output terminal is connected to the output terminal --24 leading to a signal F. ^ - the arrangement is connected.

No.344263

It is assumed that when the input terminal i of the switching circuit -48- is connected to its output terminal, a signal shown in Fig. 7b appears at the input terminal -23- of the arrangement. In this case, a signal i occurs after the delay arrangement -40-Nl and after the delay arrangement -41- the signal occurs. The signals A and B are transmitted via the superposition stage -44- to the signal /, N .Nl

- 1 +1 \ nl combined, which is the signal n

N + 1 yields. In the subsequent field duration, the input terminal i of the switching arrangement -48- is connected to its output terminal. When the signal occurs, the signal appears behind the delay device -42-

nl ^Xn + 1, which gives the signal / .N .Nl 2 \ n n + 1 via the superposition stage -46-, which ultimately gives the signal

N + 1n + 1

Partial image corresponds.

It follows that the information of two related fields forming a group for a particular line (s) of the first field i ^ from the own video signal (i ^ ^ and from an overlying line (nl) of a delayed by almost one field duration Ty Video signal of the previous (N + l ^ and for the subsequent line (n + 1) of the second field I i ^₊^ j from the video signal of the first field i & j which is delayed by almost (£) one frame time Ty and from an underlying line (n + 1) of the video signal of the preceding field i2 delayed by almost two frames Ty₊^ is formed.

The result of the signal combination is shown in Fig.llb by the signals F7i and F72, which are derived from the already described in Figs. 2 and 4 signals Al and A2, which are repeated in Fig. 11a. It can be seen that no flicker occurs when the signal F72 is reproduced. To Be11

No.344263, the signal values ​​of the signal F7g of FIG. 11b and the corresponding signals of FIGS. 11c, d and e Nl N + 1 have been assumed to correspond to the information i.

The use of the delay arrangement -41- with a delay time corresponding to the line duration ^TH results in that the line information of the two associated fields is formed of one line and the line above it for the first field and the same line and the line for the second field. Without the delay arrangement -41- would have

Nl the signal B of Fig. 7b the value i, which for the signal F n + l

Ν '

II ·, Nl ^Xn + 1 / would result. It follows from the signal F of Fig. 7b that the line information for the first and second field of the group are then identical. Compared to the gradual slope in the information patterns of the signals F7] _ and F72 shown in FIG. 11, a lower-quality image then appears, i. zw. the fact that the step-shaped character of the inclination would give a horizontally directed strip-shaped pattern in the playback.

In Fig, 8a, an arrangement is shown, which is comparable to that of Fig, 7a, but in which only a delay arrangement Ver -50- with a nearly one field duration Ty corresponding delay f ^th \ time I Ty - -y is accidental. The delay arrangement -50- is of a type in which simultaneously

Signal recording and delivery of a delayed signal can be done. The input terminal of the delay device -50-, at which the signal B is present at the output terminal of a Umschaltanord N + l tion -51-, the input terminal i is at the input terminal -23- of the arrangement with the signal ON. An input terminal i of the switching arrangement -51- is connected to an output terminal of a superposition stage -52- which is provided with an input terminal connected to the terminal -23- and to an input terminal which has a delay arrangement -53- whose delay time corresponds to a line duration Tg, is connected to the output terminal of the delay arrangement -50-. The connection point of the delay devices -50 and 53-, at which the signal C is present, which gives a signal D after the arrangement -53-, is connected via an attenuation stage --54- to an input N + 1 terminal i of a switching arrangement -55- and to an input terminal of a Uber storage level -56- laid. A second input terminal of the superimposing stage -56- is connected to the input terminal -23- via a damping stage -57-, while the output terminal of the stage -56- is connected to an input terminal N i of the switching arrangement -55- whose output terminal is connected to the output terminal -24i - The An N N + l

Order is. A signal E or F at the input terminal i or i of the switching arrangement -55- results in a signal G depending on the switching position.

In Fig. 8b, the information i are given, which occur at moments, on the one hand symbolized by the N + l a full line switch position (i) and on the other hand, symbolized by a dotted line Sehalterstellung (i ^) of the switching arrangement -51 and 55- occur. It is assumed that an ONN + l running state in which the input terminal i is connected to the output of the switching arrangement, the signal B to the signal

Nl n + l corresponds. In the following sub-picture section (i), the signal occurs at the input terminal -23- and the signal .N1 occurs at the output terminal of the delay arrangement -50-^Xn + 1

No.344263, while the output terminal of the delay arrangement -53- the signal

Nl nl leads. The superposition stage -52- forms the signal from the signals A and D.

N NI i ^{+ 1} n nl for feeding to the delay device -50-. The superposition stage -56- forms the signals i (i^N

2 \ n .Ν -! \ N + 1 / which signal gives the output signal .Ν '.

N + 1

In the subsequent sub-picture section, in which the input terminals i are connected to the outputs of the change-over arrangements, the signal .N + 1 n + 1 which supplies the signal B occurs. When the signal .N + 1 occurs^Xn + 1 at the input terminal of the delay arrangement -50- occurs at the output terminal of the same SiN N gnalanteil i in the signal C on. This signal component is supplied by the signal component i in the signal n + 2 π of the preceding field. The result is that the delay device-50- is the signal

N Nl

C = i "+ l" n + 2 n + 1 which halves the signal F resulting in the output terminal -24 * ^ - the signal

N + 1 'n + 1 of Fig. 8b occurs.

In Fig. 11c, the output signals G8 ^ and G8₂ the arrangement of FIG. 8a, u.zw. starting from the finger signals Al and A2 from Fig. Ha. From the signal G of FIG. 8b it follows that the information of a particular line (s) in the first field (Ν ') of the group of two associated fields is formed from the own information of the relevant line and the information of an underlying line (n + 1) of the preceding field (Nl) while the information of the subsequent line (n + 1) of the second field (N + 1¹) is formed by the information of the underlying line (n + 1) of the preceding field (Nl) and the information of the underlying line (n + 2) of the field corresponding to the first field (N) of the group.

No. 344263

By using the delay arrangement -53- with a delay time corresponding to the line duration Th is reached, the information of a common line (n + 1) is used to form the line information of both the first and the second field of the group and hiebei to form the line information in the first field, the information of the overlying line (s) and to form the line information in second sub-picture dielnformation the underlying line (n + 2) is additionally used. As explained in the explanation of the use of the delay arrangement -51-- in the arrangement according to FIG. 7a, the desired gradual inclination for the information medium thereby occurs in the signals G8i and G82 according to FIG. 11c.

nl

If one does not use the delay arrangement -53-, it follows that instead of the signal component i nl in the signal al

N .No ^{1 + 1} - n nl of Fig. 8b, a signal component i

Nl n + 1 occurs (originating from the signal C), which is a signal F .N + 1 '1 /, N .Nl \ ^Xn + 1 2 \ n + 2 n + 3 /. This would be used to form the line information of the first and second field of the group of four consecutive lines two and two, which patterns instead of the gradual inclination in the information results in the less desirable gradual inclination with the strip pattern in the playback.

In Fig. 9a an arrangement is shown which, in addition to the components described in the arrangement of Fig. 7a, further comprises a damping stage -49- with a factor i connected to the connection point of the delay arrangements -40 and 41-. The output terminal of the stage -49- is connected to a third input terminal of the superposition stages -44 'and 46'-, while the

1

Attenuation level -45'- has one factor - instead of - has. In the same manner as the signals A through F of FIG. 7b, the signals A through G appearing in the arrangement of FIG. 9a are shown in FIG. 9b. In FIG G9g the arrangement of FIG. 9a applied, u.zw. starting from the input signals Al and A2 of Fig. 11a. From the signal G of FIG. 9b it follows that the information for a specific line (s) in the first field (Ν ') of a group of two associated fields is formed from the own video signal ^ i J and a video signal of the preceding field (N1) delayed nearly one field duration the intended delay for obtaining the information of an underlying line (n + 1) by a line duration shorter or to obtain the information or The information for the line (n + 1) of the second subpicture (N + 1 ') of the group, which consists of the video signal of the preceding field (Nl) delayed nearly the duration of two fields. and the video signal of the first field (N) delayed nearly one field duration undergoes a delay which is shorter by one line duration for obtaining the information of an underlying (n + 2) or a delay longer by one line period for obtaining the information of an overlying line (s).

FIG. 10 a shows an arrangement which largely corresponds to that according to FIG. 8 a, in particular with regard to the use of the delay arrangement 50, which is suitable for continuous signal recording of a signal V and signal output of a signal D delayed by one field duration, and the use of the switching arrangements -51 and 55- and the superposition stage -52-. Furthermore, a delay arrangement -60- with a delay time corresponding to a line duration Th and a parallel lying superimposing stage -61- is provided which lies between the input terminal -23- of the arrangement node and the signal terminal B leading input terminal i of the switching arrangement -51-. The output terminal of the superposition stage -61- is connected via a damping stage -62- with a factor i with a signal E leading input terminal of the superposition stage -52-, the other input terminal via a damping stage -63- with a factor i with the output terminal of the delay

No.344263 ruling arrangement -50- is connected. To the output terminal of the delay arrangement -50- a delay arrangement -64- is connected with a parallel superposition stage

N + I -65- which parallel connection is connected to a signal terminal F leading input terminal i of Umsehaltanordnung -55-. The output terminal of the superposition stage -65-, which carries a signal G, has been applied via a damping stage -66- by a factor to an input terminal of a superposition stage -67-, whose other input terminal is connected via a damping stage -68- by a factor i to the output terminal the delay arrangement -60- is placed. The leading a signal H.² N

Output terminal of the stage -67- is connected to the input terminal i of the switching arrangement -55- which is connected to the output terminal leading to a signal K at the output terminal -24! - of the arrangement.

In Fig. 10b, the information i is given in the same manner as in Fig. 8b. After a start-up period with the signals

Nl n + 1 and B = C = i

Nl nl it follows that in the following field section with the signals λ ·^Ν τ »·^Ν

Α = ι, Β = 1 η-2 and thereby the signals .Nl ^Xn-1 and F = i

Nl n-3 the signal

G = - i nl .Nl 1 Nl n-3, the output signal

Ν 'of Fig. 10b occurs. During this field duration, the signal "1 .Nl 1, N nl 4 n-2 is applied to the delay device -50-. In the following sub-picture section with the signals. N + 1, "N + l

Α = ι and B = ι n + l nl occurs in the manner described in Fig. 8b, the delayed signal C as a signal

NI IN 1 .N

D = - i "+ - i" + - i n + l 4 n + 2 4 n, where the signal

nl

F = - i " _t _ nl 4 n

IN IN + - i + - i n-2 to the signal

No, 344,263

N + 1 'n + 1 at the output terminal -24-.

The signal K according to FIG. 10b is shown in FIG. 11b in the form of the signals ΚΙΟχ and KL0₂ represented by the input signals Al and A2 (Fig. 11). It turns out that the information i belonging to 5 of the lines of the first (Ν ') and second (N + 1') partial image are shifted by two successive lines in relation to the partial images (N and Nl) used for the signal combination. This shift has no disadvantages and is permissible. Compared to the signal G of Fig. 9b, the signal K of Fig. 10b has a single difference, u. tw. the shift of two consecutive lines (n-2 versus n; nl versus n + 1, etc.).

In the arrangements of Figures 7, 8, 9 and 10, no vertical aperture correction circuit is provided. However, such circuitry could be used and could be provided between the output terminal -24 ^ - and the arrangement -20-. Likewise, a HorizontalAperturkorrekturschaltung could be provided.

It should also be mentioned that inexpensive delay arrangements with a delay time of about one field duration can be used, which have only a limited frequency pass band, u.zw. in that the input terminal -23- offered a frequency-limited signal A and the output terminal -24j- are connected to a superposition stage whose other input terminal to the described arrangement according to the invention around the RF signal component is supplied.

In Fig. 5 it is illustrated how with the aid of the arrangement according to Fig. 3a, the flicker at Wieder20 would be caused by a movement in the recorded scene in the Zeilenabtast- or horizontal direction is turned off. For the arrangement according to FIG. 7a with the output signal F according to FIG. 7b, it follows that da.Nl₌ .Nl nl n + 1 for the horizontal scanning direction in both sub-images (Ν 'and N + 1') the same mean of the shifted

Signal slopes in the fields (N and Nl) occurs. The same applies to the arrangements and the signals according to FIGS. 8, 9 and 10.

A video disk with information recorded by a method according to the invention has arranged the information in groups, whereby in each group the information of the first partial image differs only to a minor extent from that in the second partial image and a movement in the scene, the 30th with different video information between successive fields, can only occur as a difference in the video information between the groups consisting of two respective sub-images.

Above solutions are given, in which at least one delay arrangement is used whose delay time corresponds to almost one field duration Ty. Another solution is possible using a delay arrangement with a delay time which corresponds to an image duration, that is to say corresponds to the duration of two partial image sections Ty. A signal may be formed for the first field of each group consisting of two fields, u.zw. according to the relationship .N-2 .N

Ν ' ^Xn ^{+ X}ni = -.

while the signal for the second field of this group corresponds to the relationship

N + 1 'Nl n. = l.

n + 1 n + 1 is formed. Thus, the information for the first field (i) becomes the mean of the immediate

N N-2 information (i) and the information (i) delayed by one frame duration; The information for the second field (i) is supplied by the information (i) delayed by one frame duration. An advantage of this is that, for a moving part in a scene, by averaging the signals of a first and a third field, the (middle) position of the part is the same as that of the one 16 in this way

No.344263 closed second part of the picture. In the absence of movement in the scene, signal processing does not affect the original signals offered.

For completeness, it should be noted that the signal processing is feasible with an arrangement of which an input terminal is immediately connected to an adder via a delay arrangement whose delay time corresponds to a picture duration, the output of the adder being connected through an attenuation stage with a factor and the output of the adder Delay arrangement are connected directly to input terminals of a switching arrangement, whose output terminal is connected to the output of the device. During the first field of each group of two associated fields, the attenuation stage is connected to the output, wherein during every other field the output of the delay device is connected directly to the output of the device.

The foregoing has described in general terms the processing of a video signal that occurs in a black-and-white television system. The description of the use of the measures according to the invention in a video signal occurring in a color television system will now be described below. It is inefficient, the signal processing on the three color television signals normally occurring in color television, which correspond to a red, green and blue field, individually, ie in triplicate.

In the arrangement of Fig. 12, a video signal source -21'- provides a coded color television signal corresponding to the applied color television system, for example a standard NTSC signal or PAL signal. The NTSC signal or PA L signal is supplied to a decode section 70, which outputs a luminance signal Y and two color difference signals RY and BY at three circuit outputs. Based on the based on the three basic colors red, green and blue color television system, where a color signal R, Gbzw. B, it follows that the luminance signal is the color signal combination

Y = 0.30 R + 0.59 G + 0.11 B is formed.

The Sehaltungsausgang the decoder circuit -70- with the luminance signal Y is connected to an input terminal -23- a -71- device. The arrangement -71- contains, corresponding to the circuit arrangements according to FIGS. 3a and 6a, the components -25... 39-. The arrangement -71- has a first and a second output terminal -24 ^ or 242-^auf> ³¹¹ which are a video signal combination in different groups of two associated sub-images (signal F of Fig. 3b or 6b) and an image sync signal before. The output terminal -242- with the image sync signal is connected to an input of an array -20 '- for recording information on a video disc. The arrangement -71- is further provided with an output for providing a switching signal, to which the output of the switching signal generator -31- of the circuit arrangement according to Fig. 3a or 6a is used.

In the arrangement according to FIG. 12, the circuit output of the decoding circuit -70- with the color difference signal RY is connected to an input of a delay arrangement -72- whose delay time corresponds to a line duration Tjj and to an input of a delay arrangement -73- whose delay time Ty + - Tjj corresponds, where Ty corresponds to a field duration. The output of a

N

Delay arrangement -72- is connected to an input terminal i, a switching arrangement -74- whose N + 1 other input terminal i is connected to the output of the delay arrangement -73-. To control the Ums chaltanordnung -74- connected to the arrangement -71- (u., To the output of the existing therein Schalttsignalgenerators -31-), whereby in the first field each of two fields

N existing group, the input terminal i is connected to the output of the switching arrangement -74- N + l and in the second field, the input terminal i. In the same way, the circuit output of the decoder circuit -70- at which the color difference signal BY occurs is connected to delay arrangements -75 and 76- whose delay time is Tjj and Ty + 3/2 Tg, respectively, to which arrangements -75, 76- a switching arrangement follows. The output terminals of the switching circuits -74 and 77-, which are combined, and the output terminal -24χ- of the arrangement -71- are at inputs of a coding circuit -78- to form a standard NTSC signal or PAL signal, which at an output to Supply to the array -20 '- becomes available for recording information on a video disc.

For an explanation of the mode of operation of the arrangement -71- according to FIG. 12, reference is made to FIGS. 3 and 6 and the associated description. The construction of the arrangement -71- in the form of one of the circuit arrangements shown in FIGS. 7, 8, 9 and 10 appears less suitable because the outputs at the outputs -24 ^ -

No.344263 obtained signal combinations directly from more or less non-contiguous video signals of several fields and lines are formed therein. On the other hand, with respect to the arrangement of Fig. 3, a modified aperture correction signal is used to match the information of the second field of each group formed with information from the first field. The configuration of the arrangement -71 "of Fig. 6 is considered to be the most suitable. The two fields of each group have their own aperture correction signal, while the main field of the second field

<img file="AT344263B_D0001.tif" />

strong agreement with that of the first field (i), as is apparent from the signal F of Fig. 6b. Accordingly, with regard to the construction and the operation of the arrangement -71-, which is provided in the circuit arrangement according to FIG. 12, reference is made to the statements relating to FIG.

The arrangement -71- in the circuit of Fig. 12 provides at the output terminal -24j- a signal F as shown in Fig. 6b, where i = Y, so that in the first field each

Group a signal Y and in the second field, the signal Y is available. During the first partial n + 1 image, signal A of Fig. 6b appears at input terminal -23- of Fig. 12, yielding Y. Gen + 2 compared to the signal at the output terminal -24] .- the arrangement -71- has a delay time corresponding to a line duration Tg, which results from the use of the delay arrangement -25- of the arrangement according to Figure 6a. At the inputs of the delay devices -72 and 73- a signal is issued

<img file="AT344263B_D0002.tif" />

occurs during the first field (N) at the output of the delay arrangement -72 or 75- a signal

NN Ν 'NN (RY) or, (BY). In the coding circuit -78-, the signals Y, (RY) and (BY) are processed to the η η η η n standardized NTSC signal or PAL signal. It can be seen that only the luminance information for performing the image frequency flicker compensation in a still image is changed while the color information has remained unchanged.

During the second field (N + 1) of each group consisting of two fields, the signal Y appears at the output terminal -24 ^ of the device -71-, and at the output terminal -23-N + 1 the signal Y ^₊₃ occurs (as can be seen from the signals F and A in Fig, 6b). In this case, the signals (RY) and (BY) occur at the inputs of the delay arrangements -72 and 73 or 75 and 76, U + 3 Πτ3 giving the delay time Ty + 3/2 Tjj of the delay arrangements -73 and 76, that occur at the outputs signals which are delayed by one field duration Ty and by 11/2 line duration Th, which

NN gives the value (RY) and (BY). Because of a delay time

<img file="AT344263B_D0003.tif" />

N follow the signals (R- Y)

NN and (BY), where the additional delay time Th is the value (RY) +

N (BY) yields.

It can be seen that the coding circuit -78- for the second field of each group consisting of two subframes beN + l 'NN contains the signals Y, (RY) ^ and (^BY)₁₁ be forwarded. Since for the first field the Ν 'NN

Signals Y, (RY) and (BY) occur, it follows that the luminance information is modified by the signal combination in the groups each containing two partial image sections, the color information in the form of color difference signals but in both partial image sections is the same. It follows that a good elimination of the image-frequency flicker occurs when playing a still image. On

No.344263

The advantage is that the delay arrangements -72, 73, 75 and 76- and in particular the delay arrangements -73 and 76- whose delay time is longer than a field duration Ty, only a limited to about 1 MHz bandwidth for processing the to 0.6 to 0.8 MHz in frequency limited color difference signals (RY) and (BY) need. For the arrangement -71- it holds that the delay arrangements used therein (according to FIG. 6a shows the delay arrangements -25, 26- with the time delay

Tg and the delay device -33- with the time delay

JH

Ty -), a bandwidth up to about

MHz, which in particular makes the delay arrangement -33- more expensive. A processing of the three color signals R, G and B, each with the full bandwidth and each with a single compensation of the flicker by a triple use of the arrangement -71- to a very unfavorable solution. It is more advantageous first to form the luminance signal Y with the full bandwidth and the frequency-limited color difference signals RY and BY (directly) with the aid of a matrix circuit of the color signals R, G and B and then the arrangement according to FIG. 12 with the components -71 to 78-.

The use of the delay arrangements -72 and 75- can be omitted in which

The result is that in the interconnected input terminals i the coding circuit -78- Ν 'NN on the supply of the modified luminance signal Y ^ the color difference signals ^^-V) n + 2 ^U.N^ +2

N + l gets fed. In the interconnected input terminals i the coding circuit N + l 'NN -78- gets the signals Y, (RY) ^₊₂^U.N^ ^The Shifting in the color information, which is taken from the line n + 2 instead of the line n, has virtually no noticeable consequences during playback.

In Fig. 13 an embodiment of the arrangement according to the invention is shown, in which the coded color television signal for an NTSC system or a PAL system originating from the video signal source -21 '- is fed to a filter bank -80- connected to a circuit output the luminance signal Y with a bandwidth up to, for example, 3.5 MHz and the modulated chrominance signal Ch with a limited bandwidth of 1.5 MHz at another circuit output. The chrominance signal Ch contains the color information on a quadrature modulated subcarrier.

The illuminating signal Y is processed in the manner described in the arrangement of Fig. 12 in the arrangement -71-. The first output terminal -24 ^ - is connected to an input of a superposition stage -81- shown as an adder. The chrominance signal Ch is applied to two delay arrays -82 and 83-, one having a delay cell corresponding to the line duration Th and the other having a delay time of Ty + 3/2 Th, which is close to one field duration Ty. The output of the delay arrangement -82- is connected to an input terminal i^Na switching arrangement -84-, which performs a changeover under control of a switching signal generator (-32-) per sub-image section, which is provided in the arrangement -71-. The output of the delay arrangement -83- is connected to an input terminal of, for example, a manually switchable switch -85- with two output terminals. To use the arrangement of FIG. 13 in a color television system with the NTSC standard, the switch -85- should be placed in the position in which its input is connected to the output terminal NTSC. This output terminal is in turn connected via an inverter circuit -86- to the input terminal i of the non-switching arrangement -84-. Similarly, for use in accordance with the PAL standard, the switch -85- should be set to the other position in which its input is connected to the output terminal PAL. The latter output terminal of the -85- switch is connected to the input terminal i via a phase switch -87-^{N + 1} the Unaschaltanordnung -84- connected. The output of stage -81 outputs an NTSC / PAL signal to the array -20-.

Taking into consideration the explanations of FIGS. 6 and 12, for the first field (N) of each group of two associated fields, the result is that upon the occurrence of the signal Y ₊₂^onDer 'the input terminal -23- the signal Y occurs at the output terminal -24i-, while at the signal n

NN

Ch ^ at the input of the delay arrangement -82- the output thereof carries the signal Ch ^. The AusΝ 'N transition of the superposition stage -81- leads thereby a signal Y ^ + Ch ^, which is a standardized NTSC / PAL 19

No.344263

Signal for the arrangement -20 '- is available, which is present in this signal to eliminate the image-frequency flicker appearance in still image playback, a modified luminance signal, but the color information is unchanged.

For the second field of each group consisting of two associated fields, N + 1 results with the aid of the above-mentioned indication that the signal Y occurs at the occurrence of the signal Y at the input terminal -23-N + 1 'at the output terminal -24i. This occurs at the entrance of the delay Anord^A n + l n -83- the signal Ch on, while at the output the signal Ch occurs. Apart from a Phan + 3 H senänderung, which also depends on the position of the switch -85- (NTSC or PAL), it follows that the N + l 'N

Output of Uber storage stage -81- a signal Y_{Q + 1} + Ch ^ leads.

Ν 'N

A comparison of the signal for the first field, which corresponds to the value Y ^ + Ch ^, with the signal for the second field, which corresponds to the value Y + Ch, shows that with a modified n + ln

Luminance information the color information is still unchanged.

Although the circuit arrangements -86 and 87- have been mentioned in the above discussions, the phase shifts between the chrominance signals of successive lines in a partial image provided in accordance with the color television standards have not been discussed in detail. For the

455

NTSC standard is that at 525 lines per full image, the color carrier frequency x should be the line frequency, while the color carrier sync signal of each line has a phase corresponding to 180 ° in the (RY) - (BY) diagram. Starting from a function for the chrominance signal:

CH

ch_Q sin 2 π x 227.5

<img file="AT344263B_D0004.tif" />

(1) follows for τ = number of line duration delays Tg, a phase shift in the chrominance signal corresponding to sin 2 π x 227.5 xl / T x number of line duration delays T. (2)

Η H

For the delay arrangement -83- of the arrangement according to FIG. 13, it follows that by its time delay T_v + 3/2 Tjj an effective time delay of the output signal corresponding to the same

Τ + -Τ = 263 T relative to the signal at the output terminal 24-, - the arrangement-71- entV 2 Η H · * stands. If the number of line duration delays is 263, it follows from relationship (2) that the phase shift is an integer multiple of 2π plus π, so that equalization of the phase shift corresponding to 180 ° is necessary for the chrominance signal. For this purpose, the NTSC terminal of UmschalN + l ters -85- via the Inverters circuit -86- connected to the input terminal i of the switching arrangement -84-.

However, if the use of the delay arrangement -82- is omitted in the manner described in connection with the explanation of FIG. 12 for the delay arrangements -72 and 75-, whereby a delay arrangement -83'- with a delay time T + T is to be provided, then so V 2 n occurs an effective delay of the output signal of the device -83 '- compared to the signal at the

Clamp -24-, from T - - T = 262 T up. From the relation (2) it then follows that a phase ver^A V 2 Η H

Shift corresponding to an integer multiple of 2 π occurs, so that no further measures need to be taken.

For the PAL standard, with a line number of 625 per frame, the color subcarrier frequency is equal to ( ¹¹³⁵\ 4 +

<img file="AT344263B_D0005.tif" />

x horizontal frequency, while the color carrier sync signal for successive lines in a field alternately has the phase 135 °, 225 °, 135 °,..., etc., in the (RY) (BY) diagram at a phase position of the color carrier sync signal of 135 ° the (RY) axis one

Nr.344263

Phase angle of 90 ° and has a phase position of the color carrier sync signal of 225 °, the (RY) axis has a phase angle of 270 °.

For the PA L chrominance signal, the function results

CH = Ch sin 2 π o ²⁸³'^{75 +} 625 (td) (3)

For the phase shift follows:

(1) 1 sin 2 πI 283.75 ⁺ -y (number of line duration delays T ^). (4) \ 'H

The time delay Ty + 3/2 Tg in the delay arrangement 83 of the arrangement of Fig. 13 results in an effective time delay of the output signal of the delay arrangement -83- from T + - T = 313 T relative to the signal at the output terminal -24₁ - the arrangement-71-. V 2 Η Η i

From the relationship (4) follows a phase shift of sin 2 ff (88813.75 + 0.5)

7Γ so that the phase shift is an integer multiple of 2 ff and -, which gives the Chromi4 nanzsignal a phase shift of 90 °. To compensate for the 90 ° phase shift, a phase shift of -90 ° for the chrominance signal is made with the aid of the phase rotator -87-.

To determine the phase of the color carrier sync signal and the associated position of the (RY) axis in the (RY) (BY) diagram, the following applies. The PAL standard specifies that the phase of the color carrier sync signal for the first complete line of a field differs from the first complete line of the subsequent field. This results in groups of 4 fields, starting from a phase of the sync signal of 135 for the first complete line in a first odd field a phase of 225 ° for the first complete line in the following second, even field, a phase of 225 ° for the first complete line in the following third, odd field and a phase of 135 ° for the first complete line in the following fourth, even field follows. The (RY) axis is at 90 ° in the Synehronsignalphase of 135 ° and 270 ° at the synchronous signal phase of 225 °. The effective time delay of the delay arrangement -83- in Fig. 13 corresponding to T + - T = 313 T indicates that phase matching must occur. For the information for V 2 Η H a complete line in a field with, for example, a phase of 225 ° for the color carrier sync signal is taken by the time delay of 313 line durations Tjj the top line of the previous field, the phase corresponding to 135 ° for the sync signal Has. The phase matching means that the chrominance information and the chrominance synchronous information must be mirrored to the (BY) ae in the (RY) (BY) diagram, which is done with the phase rotator -87-.

The phase rotator -87- in FIG. 13 is used to perform the phase adjustment of the -90 ° chrominance signal and the chrominance information and carrier synchronous information over the (BY) avex, The PAL chrominance signal Ch with the color carrier sync signal on the back porch is fed in the phase rotator -87- to an input of a signal multiplier -88- and to the input of a gate circuit -89-. Gate -89- allows only the carrier sync signal present on the back porch a frequency doubler -90- whose output is connected to an input of the signal multiplier -88-. In the signal multiplier -88- the chrominance signal Ch, that according to the function

Ch sin (ω t + φ) o occurs, multiplied by 2 sin 2 cot, where 2 ω is twice the radial frequency of the color carrier. For the function

Ch sin (ω t + cp] sin 2 ω to

No. 344263, that it conforms to the following formula:

ch_Q cos (wt - φ) - Ch_Q (3 ωί + φ), (5)

The signal of the relationship (5) appears at the output of the signal multiplier -88-, which is connected to a low-pass filter -91-. The output of the low pass filter -91- carries a signal with the function

ch_Q cos (wt - φ), which is opposite to the signal

ch_Q sin (ωί + φ) in the (RY) - (BY) diagram is a reflection from the (BY) -axis.

The output of the low-pass filter -91- is at the input of a phase rotation filter -92-, which results in a Pha10 senverschiebung of -90 °. The output of the phase rotation filter -92- is connected to the input terminal N + 1 i of the switching arrangement --84-- to supply the matched PAL chrominance signal Ch to them.

If one does not use the delay arrangement -82- and if one accordingly provides a delay arrangement 83 'with a delay time Τ + π T, the following results:

V 2 H

The effective delay time of T - i T = 312 T indicates that the information for a V 2 Η H

If one takes into account the groups consisting of four sub-pictures according to the PAL standard, it follows that the phase of the chrominance synchronizing signal and the (RY) axis does not require any change. From the relation (4), it is found that the chrominance information undergoes a phase shift corresponding to sin 2 π (88530 + 0.5), so that a phase shift corresponding to an integer multiple of 2π plus π results. To compensate for the phase shift of 180 ° can be used as a phase inverter inverter circuit.