FR2499342A1 - BAND FORMAT FOR A HELICOIDAL EXPLORATION VIDEO RECORDING AND RETURN SYSTEM AND EXPLORATION DEVICE FOR USE THEREIN IN RECORDING AND RETRACTING SYSTEMS - Google Patents

Abstract

THE PRESENT INVENTION RELATES TO HELICOIDAL EXPLORATION VIDEO TAPE RECORDING OR RESTITUTION SYSTEMS. ACCORDING TO THE INVENTION, IN A BAND FORMAT, SEPARATE U1U2, V1V2 RECORDING TRACKS ARE ARRANGED IN A NUMBER OF U, V, W LONGITUDINAL SEGMENTS ON THE TAPE AND EACH TRACK CONTAINS A CERTAIN NUMBER OF U1, U2 DISTINCT PARTS EACH OF WHICH IN COMBINATION WITH AT LEAST ONE OTHER DISTINCT PART V1, W1 OF ANOTHER LONGITUDINAL BAND SEGMENT RELATES TO AN INDIVIDUAL VERTICAL SEGMENT OF A TELEVISION FRAME; THE VARIOUS COMBINATIONS OF THE TRACK PARTS RELATE RESPECTIVELY TO VERTICAL AND DIFFERENT SEGMENTS OF THE WEFT WHICH TOGETHER CONSTITUTE THE COMPLETE WEFT. THE PRESENT INVENTION IN PARTICULAR ALLOWS THE RESTITUTION OF RECOGNIZABLE IMAGES AT SPEEDS OTHER THAN RECORDING, WITH A REDUCED LIMIT ON THE DATA FATURES WHICH CAN BE TAKEN INTO ACCOUNT.

Description

The present invention relates to a tape format for a system

  for recording and video playback with helical exploration and the device to be used for this purpose, in recording and / or reproduction systems, and represents an improvement made to the patent application filed in France under number 81.01 . 503 January 27, 1981 and hereinafter referred to

"The domestic invention".

  Helical exploration video recording and / or playback systems are known, where each track track that is explored relates to a known segment of an image or a complete grid of information.

  of TV. Such systems can be

  put an automatic loading of the tape using an active exploration angle of less than 3600 (for example or 2400), with a scanner having an equal circumference

  or smaller than the track length per image or grid.

  These systems include complex treatment devices

  signals to organize and synchronize the video information when it is rendered at longitudinal speeds of the tape, other than the recording speed. In such systems, the address information is embedded in the video information on each track and a memory is incorporated in the signal processing device to sufficiently organize and synchronize the video information to obtain a recognizable image. The complexity of signal processing devices has been reduced in recording and / or

  unseen exploration using an active angle of

  substantially 360? However, the automatic loading of the tape is not yet possible with a

  active exploration angle of approximately 3600 and consequently

  such an arrangement is not widely used.

  Automatic strip loading is possible in non-segmented exploration systems using an active exploration angle of 1800, but in order to obtain a given track length per image or grid, the diameter

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  scanner needs to be doubled compared to the system

  having an active exploration angle of substantially 3600.

  Of course, such an increase in the size of the scanner dramatically increases the size of the recording and / or rendering system and it is a problem

  particularly in the portable versions of such a system.

  According to the principle of the prior invention, video information relating to individual vertical segments of a television frame is recorded on separate tracks in longitudinal segments of the web, for synchronizing grid or image information.

  adjacent without the use of a complex treatment device

  signal when the tape is replayed at speeds other than the recording speed. In the recording and / or reproduction unit, a number of transducers in number equal to the desired amount of vertical frame segments are also

  spaced apart on the rotator scanner, each trans-

  driver having a single location along the axis

  cylindrical or rotation of the scanner.

  According to this. nvention, there are still separate tracks in a number of longitudinal segments

  of the tape, but each of these tracks contains a -

  a number of distinct sections of runway each of which incombined with another of these distinct portions of another longitudinal segment of the runway, relates to an individual vertical segment of the television frame. The various combinations of the track portions relate respectively to different vertical frame segments which, together, constitute the complete frame. This modified format reduces the limit of the data rate which will be explained hereinafter. will be better understood, and other goals,

  characteristics, details and advantages of it

  more clearly in the explanatory description

  which will follow made with reference to the accompanying schematic drawings given solely by way of example illustrating an embodiment of the invention, and in which:

  FIG. 1 illustrates the band format to be explored

  In one embodiment of the present invention, separate tracks are arranged in a number of longitudinal segments on the strip, A indicating the bandwidth; FIG. 2 illustrates the relationship of the tracks in each longitudinal segment of FIG. 1 to the individual vertical segments of a television frame and the relation of adjacent exploration points along the

  tracks in each longitudinal segment at the same location

  on the frame; FIG. 3 illustrates a transducer scanning arrangement with which the tape format of FIG. 1 can be explored; FIG. 4 illustrates the helical exploration band format for another embodiment of the prior invention; Fig. 5 illustrates the relationship of the longitudinal band segments of Fig. 4 with individual and vertical frame segments and the relationship of adjacent exploration points along the tracks in each longitudinal segment at the same frame location; FIG. 6 illustrates a transducer exploration arrangement by which the band format of FIG. 4 can be explored; and FIG. 7 illustrates a particular validation sequence for the transducers of the arrangement of FIG. 6; FIG. 8 illustrates a helical exploration tape format according to the present invention; FIG. 9 shows the relationship of track portions in the longitudinal segments of the band of FIG. 8 with individual vertical segments of the frame; and - Figure 10 shows a particular validation sequence for exploring the band format of the figure

  8 with the transducers in the arrangement of Figure 6.

  A band portion is shown in FIG. 1 with a helical exploration track format according to the prior invention disposed thereon. In this format, separate tracks of the video information are disposed in each of the two longitudinal segments X and Y across the band. As can be seen in FIG. 2, the video information in the tracks of the longitudinal segments X and Y relates to individual vertical segments X 'and Y' of a television frame, the adjacent points of exploration along of tracks in each segment being related to the same location of

  the frame as shown in Figures 1 and 2.-

  Depending on the pace of the data of the information to be recorded, more than one track of each segment of tape may relate

  to individual and vertical frame segments. However, -

  for the simplicity of the description, each track in a

  band segment refers to a full frame segment, so the video information that is represented by the centralized points on the-tracks in the X and Y segments

  Figure 1 relates directly to the central points of

  in the vertical frame segments X 'and Y'

respectively in Figure 2.

  A transducer scanning arrangement for recording and / or reproducing the tape format of FIG. 1 is illustrated in FIG. 3 where the transducers and 12 are also spaced from each other around the periphery of a scanner. 14 which rotates to explore the web 16 which is guided around by uprights 18 and 20. Each transducer 10 and 12 is also uniquely placed in the direction of the cylindrical axis of the scanner and the uprights 18 and 20 guide the web 16 around the scanner 14 about 1800 of its periphery. When more than one track in each band segment relates to the vertical frame segment, a number of transducers in a group are disposed at each peripheral location on the scanner, the transducers of any group being suitably arranged along the the direction of

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  the cylindrical axis of the scanner to simultaneously explore substantially adjacent tracks in the appropriate segment

Of the band.

  Since the tracks in the longitudinal X and Y segments of the tape contain video information which relates only to the vertical segments X 'and Y' respectively, a larger amount of coherent frame information is explored from the tape format. Fig. 1 when this tape is rendered at a higher speed than this recording meter in comparison with traditional segmented helical exploration formats. This will be better understood by considering the situation where a large number (approaching infinity) of transducers is arranged on the scanner to explore tracks in a similarly large number of longitudinal segments on the band, with each longitudinal segment relating to individual and vertical frame segments. So when tape 16 is played back or replayed at a faster speed

  higher than that of registration, some information

  The video coverage of each vertical segment of the frame is captured during successive turns of the scanner and therefore a more recognizable image is obtained directly from the video information being scanned. Accordingly, if the quality of the image is not of great importance, the address information on the tape and the memory in a signal processing device which is traditionally used to obtain a recognizable image under conditions fast restitution becomes useless. Figure 1 is not to scale and therefore it may be difficult to understand that the strip segments that relate to coherent frames are vertically aligned across the width of the band. In a typical application, each strip is 406, 4 mm long and 0.127 mm wide, thus controlling the scanner rotation speed 14, the longitudinal speed of the strip 16 and the helical winding of this strip on the scanner 14 the vertical alignment of the tracks can be achieved for coherent frames,

  As one can guess from reading the description

  In the foregoing concept of the invention, only a number of longitudinal band segments are required, each segment containing video information tracks relating to vertical and individual frame segments. Furthermore, for a given length per image or television grid, the diameter of the scanner 14 can be reduced while maintaining the quality of the recognizable image in fast playback conditions. This is accomplished by increasing

  the number of longitudinal segments individually

  to an equal number of vertical frame segments. FIG. 4 shows a part of the strip with a helicoidal exploration track format for such an embodiment. In this format, separate tracks of the video information are arranged in each of the three longitudinal band segments U, V and W. As can be seen in FIG. 5, the video information in each track of the segments U, V and W relates to individual vertical segments U ', V' and W 'respectively

  of a television frame, the adjacent points of

  along the runways in each segment being related to

  with the same location of the frame as illustrated in FIGS. 4 and 5. In these figures, the video information represented by the centralized points on the tracks in the segments U, V and W relates directly to the centralized points in the vertical segments of frame U ',

V 'and W' respectively.

  A transducer exploration arrangement for recording and / or rendering of the tape format

  FIG. 4 is illustrated in FIG.

  Conductors 30, 32 and 34 are also spaced from each other around the periphery of a scanner 36 which rotates in a recording and / or playback unit to explore the web 38 which is guided around it by uprights 40 and 42. Each transducer 30, 32 and 34 is also uniquely placed in the direction of the cylindrical axis of the scanner and the uprights 40 and 42 guide the band 38 around the scanner 36 out of 2400 around it. In this embodiment, the video information relating to a complete television grid can be scanned on the tape 38 for each turn of the scanner 36 by validating the transducers 30, 32 and 34 in succession over 1200 of the rotation of the scanner. However, smaller scanner diameters were obtained with this embodiment by validating the transducers 30, 32 and 34 in succession on 2400 rotation of the scanner, so that a complete television picture is scanned on the tape for two turns of the scanner 36, as shown in FIG. 7 where B indicates a scanner revolution, C indicates two scanner laps, or a television image, U, V, and W indicate the segments of the tape and D indicates the

rotation of the scanner.

  Those skilled in the art will realize without further explanation, that as the data rate increases, the rotational speed of the scanner and / or the longitudinal velocity of the web may

  to be increased somewhat to respond to the situation.

  However, a response limit to the data rate will exist due to losses in the transducer core and / or band gap losses and these limitations.

  can not be avoided by increasing these speeds.

  Reference was made to an attempt to avoid this limitation with the tape format of the prior invention, in that a number of transducers could be used to record more than one track related to an individual vertical segment of frame in each longitudinal band segment. According to the present invention, to overcome this limit, each track recorded in a longitudinal band segment contains discrete portions each of which relates to different vertical frame segments. Then, by combining the track portions of different longitudinal segments of the web to derive each vertical frame segment, a number of transducers can be simultaneously enabled during web exploration. A portion of the helicoidal tracking format tape according to the present invention is shown in FIG. 81 which is similar to the format of the tracks of FIG. 4 because separate tracks of the video information are disposed in each of the three longitudinal segments. However, in the format of FIG. 8, each track contains more than a portion of the video information. Each track part

  is simultaneously explored with another part of the track-

  longitudinal segment different from the band for

  worm a particular vertical segment of weft, as we

  shown in Figure 9. The transient exploration arrangement

  The drivers of FIG. 6 will be adapted for recording and / or reproducing the band size of FIG. 8 by simultaneously enabling pairs of transducers 32 and 34 to explore combinations of the track portions of the different longitudinal band segments.

  as can be seen in Figure 10.

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R E V E N D I C AT I 0 NS

  A tape format for a helicoidal video recording and playback system, characterized in that separate recording tracks (U1 / U2, V1 / V2) are arranged in a number of longitudinal segments (U, V, W) on the web, each track containing a number of distinct parts (U1, U2) each of which in combination with at least one other part

  separate track (V1, W1) from another longitudinal segment

  of the band, refers to an individual vertical segment

  duel (T1 + V1, U2 + W2) of a television frame, the various combinations of the parts of the track relating respectively to different vertical segments

  frame forming together the complete frame.

  2. Format according to claim 1, characterized in that there are three longitudinal segments of the strip and in

  that each track has two distinct parts specified

  each one contributing to a vertical segment of a

sixth of the frame.

  3. Device for recording and / or rendering video tape with helicoidal exploration, characterized in that a certain number of transducers (30, 32, 34) arranged at equally spaced locations on the periphery of a rotary scanner (36 around which the band

  (38) will be guided during its use for an explo-

  less than 360, having unique locations in the direction of the axis of rotation of said scanner, thereby cooperating with separate longitudinal segments (U, V, W) of the strip, and that means are provided to activate each transducer for different periods ms overlapping at least with respect to another of said transducers during the rotation of the scanner so as to effectively explore separate portions of the separate tracks in the corresponding longitudinal band segment; track (U1, V1; U2, W1) which are simultaneously explored in different longitudinal segments during the overlapping periods together relating to a respective one of a certain number of vertical segments (U1 + V1, U2 + W1)

of a television frame.

  4. Device according to claim 3, characterized in that there are three transducers which are each activated during successive periods substantially 240 with inactive intermediate periods substantially 120, the beginning of said periods of 240 for the various transducers being offset substantially 120, so each track in each longitudinal segment of the strip is explored in two successive parts, each of which is explored simultaneously with a portion of the track of another longitudinal segment of the strip, and thus relate both to a vertical segment

  particular a sixth of the TV frame.