DE1049907B - Method and circuit arrangement for the simultaneous visualization of several video signals originating from different television scanners on the same screen - Google Patents

Description

The invention relates to a method for visualizing a plurality of different television scanners originating video signals on the same receiver screen. Come as a television scanner z. B. television cameras, film scanners, slide scanners and magnetic tape scanners into consideration.

It is known that two television images recorded by different cameras are thereby in one image to unite that the signals emitted by one camera in Äustalstlücken that of the second camera supplied signals are displayed. However, this method has the disadvantage that from both television images only the part that is complementary to the other image is visible on the display page can be made. .

In known television studio transmission systems which use multiple television scanners, are the video signals supplied by these television scanners on the screen of a television receiver (Preview monitor) made visible and one of them selected for further transmission. In order to there is the possibility to test each of the pictures for their image effect and their artistic content, before one of them is put on the transmission path and thus visible to a larger audience is made.

But there are transmission systems that are so large for economic reasons Do not justify the effort of preview monitors, and also those with which it is in view of the for Available space is not possible, each of the generated video signals on its own preview monitor to make visible. In some cases one has made up for it by being a whole has only provided two monitors, the first being a preview monitor, on which can be optionally set each of the generated video signals can be made visible, and wherein the second monitor as the end monitor that already shows the selected image to be transferred. This method has naturally has the disadvantage that not all video signals are made visible at the same time.

The aim of the invention is to provide a switching arrangement which neither involves the great expense of one Preview monitor for each video signal makes it necessary yet has the disadvantage of only having one of the images at a time to show on a preview monitor.

It has been a method for combining a plurality (n) television images, which are taken from different image pick-up cameras, and played together on the same screen reception proposed. In this case, the deflection devices for one or both deflection directions of the image pickup tubes are operated by the same deflection current method and circuit arrangement

for simultaneous visualization

several of: different;

From television scanners

Video signals on the same screen

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Applicant:
Rank Cintel Limited, London

Representative: Dr.-Ing. -W; Lampert, patent attorney,>
Stuttgart-Frauenkopf, Distlerstr. 33 '~'^; - / - ^:

Claimed priority: ■■: ■

Great Britain from February 18, 1957 ^: '

Gilbert Nicholls, Chislehürst, Kent (Great Britain) ', has been named as the inventor. . ■;

flowed through or operated with the same deflection voltage, and the written grid is w times larger than the usable area of the picture electrodes and is offset differently from this in the individual cameras, so that in the individual image pickup tubes the same number of lines is scanned as on the associated part of the display screen.

According to the invention, in addition to the horizontal and vertical frequency sawtooth pulses H and V for the deflection systems of the television scanner, further sawing! tooth pulses H ' or V generated and fed to the ■■ deflection systems of the television receiver / whose ■ pulse repetition frequency is an integer fraction; the horizontal H and / or ' the vertical sawtooth pulses V is. According to a feature of the invention, the cathode ray modulation is switched over in accordance with the respective phase positions of the further sawtooth pulses H ' or V and thus in accordance with the respective position of the pixel moving across the screen, so that several video signals are each converted into one! specific area of the screen can be made visible. ' ^::

It is particularly advantageous if you can optionally set either at least two video signals on the single screen or one at a time

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Can make video signals visible on the same screen ^. A circuit arrangement relating to this can be used, for example, in television broadcast vehicles and in television reportage systems in order to better utilize the limited space available or to enable all images to be made visible at the same time and to save weight. However, this circuit arrangement also proves to be advantageous in all those cases in which several television scanners are used, whereas the expense of one video monitor per television scanner does not appear to be economically viable. If, for example, four television cameras are used when observing road traffic in order to observe traffic accumulations at different points in a traffic network, then it is very advantageous to _{: make} four complete but reduced images visible on a single screen using the four camera video signals. If an interesting traffic situation occurs at one of the four places viewed by the cameras, this can be made visible either on a second screen or on the only screen on which the four small images can be seen beforehand - ideally by switching with a push-button was. In this way it is possible for the traffic officials to get a good overview of the four points of the traffic network in spite of a single television screen.

To carry out the invention are Kipp'spän-. Voltage generators are required, which on the one hand deliver horizontal and vertical frequency sawtooth pulses H and V , whose frequency and phase position match those sawtooth pulses H and V , which are fed to the television scanners, and which on the other hand generate further periodic sawtooth pulses H ' and V , their maximum Amplitudes those of the horizontal or. correspond to vertical-frequency sawtooth pulses H or -F, the pulse repetition frequency of which, however, is only an integer fraction of the frequency of the horizontal and / or vertical sawtooth pulses H or V , respectively. ■ It is also necessary to provide a switch which, in order to make only one of the images corresponding to the video signals visible on the single screen, causes the horizontal and vertical frequency sawtooth pulses H or V to be fed to the deflection elements of the television receiver Delivery of the further periodic sawtooth pulses H and V causes.

Finally, it is necessary to provide another switch, which is only used for visualization one of the images corresponding to the video signals on the single screen, the modulation of the screen cathode ray each with only -dem causes a corresponding video signal and which. to Visualization of multiple video signals on a single screen the modulation of the screen cathode ray thus causes the images corresponding to the video signals to appear on the screen become visible.

If two television cameras are available in the first embodiment of the invention, each of which generates a video signal, then there is the possibility of making these two video signals visible on a single screen provided in such a way that the two images come to lie next to one another, with each of the images is displayed with an aspect ratio of 2: 3 instead of the usual 4: 3 aspect ratio. The pulse repetition frequency of the flip-flop H ' hur should be half the pulse repetition frequency of the flip-flop H. The maximum amplitudes of the tilting pulses H ' are equal to the maximum amplitudes of the tilting pulses H, since in every case scanning of the screen in the entire line direction is required. The amplitudes of the tilting pulses H ' differ in the individual moments, however, in general (with the exception of the maximum amplitudes) from those of the tilting pulses H. On the other hand, the vertical tilting pulses V for the television receiver are the same as those vertical frequency tilting pulses V, as they are also supplied to the television camera.

In this first exemplary embodiment, a switching stage has the effect that while only one image - corresponding to one of the video signals - is visible to the television receiver. Tilt pulses H and V are supplied. In contrast, while both images are becoming visible (on the television receiver), the H ' and V tilting pulses are supplied.

In this first embodiment, the further switching pin causes the cathode ray modulation of the picture tube with the first or the second video signal to be effected during the time period during which only one of the images (corresponding to either the first or the second video signal) is visible on the screen . However, during the period of time during which both images are visible on the screen, the further switching stage causes; ' that the cathode ray modulation of the picture tube during the 1st, 3rd, 5th ... (odd) H- pulse is modulated with the first video signal and that the cathode ray modulation - during the 2nd, 4th, 6th. . . (even) ff-flip-flop is modulated with the second video signal. '.. ·.'

As a second particularly well-proven embodiment of the invention, the above-mentioned arrangement is described in more detail, in which four television scanners are provided, which respectively deliver a first to fourth video signal. If these four video signals are made visible at the same time on the single screen, then its image area is advantageously fully utilized and the individual images are not distorted, since their aspect ratio of 4: 3 is maintained. The frequencies of the tilting pulses H ' and V each correspond to half the frequencies of the tilting pulses H and V. The maximum amplitudes achieved by the tilting pulses H' and V are again equal to the amplitudes of the tilting pulses ff and V, whereas the amplitudes currently achieved are equal to each other only equal if the maximum amplitudes are reached both in the H ' or V and in the ff or F tilt pulses. The provided switching stage has the effect that normal tilting pulses H or V are supplied to the television receiver during the period of time during which only one of the four images appears on the television receiver. During the time period during which all four images appear on the screen at the same time, the switching stage causes the application of the tilting pulses H ' and V,

In a further switching stage is effected in this second embodiment that during the If only a single image becomes visible (on the television receiver screen), cathode-ray modulation the picture tube with only one

umpteen of the four video signals occurs. During the period of time when all four images are taken at the same time become visible on the single screen, the further switching step has the effect that during the 1st, 3rd, 5. ... H-tilting pulse the first video signal and during of the 2nd, 4th, 6th ... H tilting pulse the second Video signal is used for modulation, provided that the 1st, 3rd, 5th ... F-tilting pulse occurs at the same time. However, if the 1st, 3rd, 5th ... if-impulse with the 2nd, 4th, 6th ... F-tilt pulse coincides in time, then causes the further switching stage a cathode ray modulation with the third video signal, and if so the 2nd, 4th, 6th ... H tilting pulse with the 2nd, 4th, 6th ... i ^ tilt pulse coincides, then there is a modulation with the fourth video signal.

Provided that there is a distortion of the images made visible on the single screen at the same time can not be avoided, it is appropriate to choose the switching means so that each of the simultaneously appearing images has the same distortion. Optical means can also be provided, in order to at least partially effect a correction of the distorted image formats of the individual images.

In the following, embodiments of the invention are explained in more detail with reference to FIGS. Show it

Fig. 1 to 4 arrangements of several images appearing on the screen at the same time,

Fig. 5 is a block diagram of a system, by means of which on a television screen either only one image or several images can be made visible at the same time.

Figure 1 shows the images corresponding to two video signals on a single television screen. One of these video signals resulted from the scanning of a circle displayed on a uniform background, the other from the scanning of a square. In this case, the horizontal frequency of the tilt pulses if is half the frequency of the normal tilt pulses H, but their maximum amplitude and the frame frequency of the tilt pulses V remain the same (V = V). The result is that the aspect ratio of each of the images is distorted by a ratio of 3: 2 instead of the standard 3: 4. The images are still recognizable, the quality of which is sufficient for some applications, and it can even be advantageous for some purposes if a distortion occurs in one of the scanning devices.

Fig. 2 shows another possibility of image display in which the horizontal frequency has remained unchanged (H '= ¹ H) and the image frequency is only half as large, while its maximum amplitude was kept at a constant value. In this case, the aspect ratio of both images becomes 3: 8, and in general these images are less easy to see than those of FIG. 1.

It is of course possible to make an arrangement with the aid of which the images according to FIG. 1 or those according to Fig. 2 appear at least partially in their correct image format through a large cylindrical lens.

Figure 3 shows a different and improved display in which the two images have the correct 3: 4 aspect ratio. For comparison, the dashed border A shows the dimensions of the largest picture, which can be reproduced in a ratio of 3: 4. The center lines were also drawn in dashed lines to indicate the arrangement of four images with an aspect ratio of 3: 4, as was described in the second exemplary embodiment.

4 shows two images of maximum image size the only screen provided that the correct picture format (aspect ratio 3: 4) is required. Here, too, the dashed line shows the size of the largest in the ratio 3: 4; bare simple picture.

The block diagram according to FIG. 5 shows a studio system, which can be optionally set either to generate a single, maximally large image

ίο (aspect ratio 3: 4) or two smaller pictures (each of which has an aspect ratio of 3: 4

■ indicates) is suitable.

A first video signal (from a first television scanner, not shown) is fed to the circuit

! 5 via terminal 1 and a second video signal (from a second television scanner, not shown) is supplied via terminal 2. One of these video signals is passed through one of the ports 3 or 4 to the amplifier 5, the output of which is connected to the control electrode of the cathode ray tube 6. The gates 3 and 4 are controlled with the aid of a switching stage 7 in such a way that either only the first video signal (via terminal 1) or only the second video signal (via terminal 2) is fed to stage 5. This control, which can also alternate periodically, is brought about by control signals which are fed to the switching stage 7 via the contacts Ci ₁ + a _v a ₂ + a ₄ , a ₃ + a _{4 of} the switch A. In the order of the mentioned contact combinations a _± + <x ₄ , a ₂ -f- Ci ₁ , a ₃ + a ₄ either a voltage with a potential P ₁ or a voltage with a potential P ₂ or a periodic pulse voltage (by means of switching stage 7) is applied to gates 3 and 4. The periodic pulse voltage consists of square pulses (meander voltage), the duration of which is equal to the duration of the (normal) tilting pulses H, ά. H. is therefore equal to the duration of a normal line and whose maximum amplitudes correspond to the potential values P ₁ and P _2. The gate 3 is always opened by the potential P ₁ . and blocked by the potential P ₂ , whereas, conversely, the gate 4 is opened by the potential P ₂ and blocked by the potential P _1. This square-wave signal is obtained in the synchronization switching stage 9, which is fed by a multivibrator (not shown) with the necessary synchronization pulses, such as by the. Arrow 10 was indicated. The cathode ray tube 6 receives the required high voltage from Stufeil. The electron beam generated in the cathode ray tube 6 is by means of the deflection coils of. Stage 12 deflected. The horizontal deflection pulses H are generated in the horizontal tilt generator 13 and fed to the corresponding horizontal deflection coil in stage 12 via contact I) ₁ of switch B. The frequency of the deflection pulses H corresponds to the frequency of those deflection pulses which are used in the extraction of the video signals. Deflection pulses H 'are generated in the horizontal tilt generator 14, the frequency of which corresponds to half the frequency of the pulses H generated in the tilt generator 13. By means of the switch B , the deflection pulses H ' generated in the horizontal tilt generator 14 can be sent via the contacts b ₂ and b _s to the corresponding deflection

level 12 bobbins.

Via an output stage 15 and via contacts C ₁ and C ₃ of switch C, vertical deflection pulses V are fed to the vertical deflection coils of stage 12. The vertical deflection pulses V are generated in the vertical tilt generator 16, and their frequency

is equal to the frequency of those vertical deflection pulses which are used in the extraction of the video signals. In addition, a vertical tilt generator 17 is provided in which vertical deflection pulses V are generated (frequency of V ' = ¹ U frequency of V). These deflection pulses V can optionally be fed to the vertical deflection coils of the stage 12 via the contacts C ₂ and C _{3 and via the output stage 15.} Both the horizontal tilt generators 13 and 14 and the vertical tilt generators 16 and 17 are synchronized from stage 9.

If you want to make only the one picture which corresponds to the first video signal visible on the single screen of the cathode ray tube 6, then the switches A, B and C are left in the switch positions shown.

If, on the other hand, you want to make the second image visible on the screen of the cathode ray tube 6 in accordance with the second video signal - only in full size - then the switch A is turned in such a way that the contacts a ₂ and a _{i are} conductively connected to one another.

. If one wants to it - corresponding to the first and second video signals - both images (. As shown in Figure 3 with fully drawn lines) simultaneously on the screen of the cathode ray tube 6 bring showing, the switch A is provided such that the contacts _a3 and a ₄ are conductively connected to one another, and in addition the switch B is rotated such that the contacts b ₂ and b _{z are} conductively connected. The electron beam of the cathode ray tube 6 is then modulated with the first video signal supplied via terminal 1 when it passes over the first half line (corresponding to H '/ 2) , since the gate 4 blocks (amplitude of the meander voltage is equal to P ₁ ). The time required for this is the same as that of a normal line. While crossing the second half of the first line, the first video signal is blocked and the second video signal is allowed to pass, because the meander voltage now (for the duration of a whole, normal line) the ampli: 4 are made visible at the same time, so that only a part of the screen is used either in the horizontal or in the vertical direction, it is sometimes useful to provide a switch by means of which a switch can be effected instantaneously, so that the two images in

- be widened horizontally or in the vertical direction and thereby cover the entire screen area.

has tudenwert P ₂ .

45

Around. To bring these ■ two images on the screen of the cathode ray tube about as in Fig. 4 to display, you will turn switch C in place of switch B in the last measure taken so that the contacts C ₂ and C _{3 are} conductively connected to each other .

In order to effect the optionally adjustable switchover for visualization - either one of the two images alone or the two images together - with push-button operation, switches A, B and C are controlled in a known manner by means of relays and pushbuttons (not shown) as described above . ■ · ■.

It is of course also possible to reproduce the two images in such a way that they are partially on the screen overlap the cathode ray tube. Thus, in the arrangement according to the invention according to FIG the top and bottom edges of the two images overlap by approximately 16 °. This fact only becomes minor difficulties and growth allow 10% in the height of each image. This arrangement then becomes particularly advantageous be if a cathode ray tube with a rectangular shape Screen used for presentation

will. ■ ■ ■ ■ .. ·, ■■

.If on the. Cathode ray tube screen 6 two images with one. Aspect ratio

from

Claims (8)

Patent claims: 1. A method for the simultaneous visualization of several video signals originating from different television scanners on the same receiver 'screen, characterized in that in addition to the horizontal and vertical frequency sawtooth pulses (H and V) for the deflection systems of the television scanners further sawtooth pulses (H' or V ) are generated and fed to the deflection systems of the television receiver, whose pulse repetition frequency is an integer fraction of the horizontal (H) and / or vertical sawtooth pulses (V) , and that corresponding to the respective phase positions of the further sawtooth pulses (H 'or V) and thus accordingly Depending on the position of the pixel moving across the screen, the cathode ray modulation is switched over in such a way that several video signals are visible in a specific area of the screen. 2. The method according to claim 1, characterized in that either at the same time either the optional images corresponding to a plurality of video signals or one of each of the images corresponding to the video signals Images become visible on the same screen. 3. The method according to claim 1, characterized by such an adjustment of the sawtooth amplitudes, that the images (Fig. 3 and 4) made visible on the same screen (of 6) can be reproduced in undistorted picture format. 4. The method according to claim 1, characterized in that with optical means at least partially corrected the distorted image formats of the individual images (FIGS. 1 and 2) will. , 5. Method according to Claim 1, characterized in that the frequency of the further vertical sawtooth (V) is equal to half the vertical frequency and the frequency of the further horizontal sawtooth (H ') is equal to the horizontal frequency (H) , so that two on the screen (from 6 ) superimposed images (Fig. 4) are visible. 6. Circuit arrangement for performing the method according to claim 1, characterized in that breakover voltage generators (13, 14, 16, 17) are provided, which the horizontal and vertical frequency sawtooth pulses (H or V) and the further sawtooth pulses (H ' or V) generate. 7. Circuit arrangement for performing the method according to claims 1 and 2, characterized by switches (B, C) which, when made visible, only one of the images corresponding to the video signals on the single screen ■ (from -6) the feeding of the horizontal and ■. vertical-frequency sawtooth pulses (H or ■ ¥). ■ to the deflector of the television receiver and at. Visualization of several ■ video signals cause the supply of the further periodic sawtooth pulses (H ' or V). 8. Circuit arrangement for carrying out the method according to claims 1 and 2, characterized by a further switch (A) which, when only one of the images corresponding to the video signals is made visible on the single screen, the continuous modulation of the cathode ray with only one ent- 10 speaking video signal and when several video signals are made visible on the single screen the alternating modulation of the cathode ray causes, the change through in time the horizontal and / or vertical frequency controlled Gate connections are made. Legacy Patents Considered:
German Patent No. 1 009 228. 1 sheet of drawings